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Sample records for cespitosa ecotype warynski

  1. Effect of chemophytostabilization practices on arbuscular mycorrhiza colonization of Deschampsia cespitosa ecotype Warynski at different soil depths

    NARCIS (Netherlands)

    Gucwa-Przepióra, E.; Malkowski, E.; Sas-Nowosielska, A.; Kucharski, R.; Krzyzak, J.; Kita, A.; Römkens, P.F.A.M.

    2007-01-01

    The effects of chemophytostabilization practices on arbuscular mycorrhiza (AM) of Deschampsia cespitosa roots at different depths in soils highly contaminated with heavy metals were studied in field trials. Mycorrhizal parameters, including frequency of mycorrhization, intensity of root cortex colon

  2. Effect of chemophytostabilization practices on arbuscular mycorrhiza colonization of Deschampsia cespitosa ecotype Warynski at different soil depths

    NARCIS (Netherlands)

    Gucwa-Przepióra, E.; Malkowski, E.; Sas-Nowosielska, A.; Kucharski, R.; Krzyzak, J.; Kita, A.; Römkens, P.F.A.M.

    2007-01-01

    The effects of chemophytostabilization practices on arbuscular mycorrhiza (AM) of Deschampsia cespitosa roots at different depths in soils highly contaminated with heavy metals were studied in field trials. Mycorrhizal parameters, including frequency of mycorrhization, intensity of root cortex colon

  3. Effect of chemophytostabilization practices on arbuscular mycorrhiza colonization of Deschampsia cespitosa ecotype Warynski at different soil depths

    NARCIS (Netherlands)

    Gucwa-Przepióra, E.; Malkowski, E.; Sas-Nowosielska, A.; Kucharski, R.; Krzyzak, J.; Kita, A.; Römkens, P.F.A.M.

    2007-01-01

    The effects of chemophytostabilization practices on arbuscular mycorrhiza (AM) of Deschampsia cespitosa roots at different depths in soils highly contaminated with heavy metals were studied in field trials. Mycorrhizal parameters, including frequency of mycorrhization, intensity of root cortex

  4. Effect of chemophytostabilization practices on arbuscular mycorrhiza colonization of Deschampsia cespitosa ecotype Warynski at different soil depths

    Energy Technology Data Exchange (ETDEWEB)

    Gucwa-Przepiora, E.; Malkowski, E.; Sas-Nowosielska, A.; Kucharski, R.; Krzyzak, J.; Kita, A.; Romkens, P.F.A.M. [University of Silesia, Katowice (Poland)

    2007-12-15

    The effects of chemophytostabilization practices on arbuscular mycorrhiza (AM) of Deschampsia cespitosa roots at different depths in soils highly contaminated with heavy metals were studied in field trials. Mycorrhizal parameters, including frequency of mycorrhization, intensity of root cortex colonization and arbuscule abundance were studied. Correlations between concentration of bioavailable Cd, Zn, Pb and Cu in soil and mycorrhizal parameters were estimated. An increase in AM colonization with increasing soil depth was observed in soils with spontaneously, growing D. cespitosa. A positive effect of chemophytostabilization amendments (calcium phosphate, lignite) on AM colonization was found in the soil layers to which the amendments were applied. Negative correlation coefficients between mycorrhizal parameters and concentration of bioavailable Cd and Zn in soil were obtained. Our results demonstrated that chemophytostabilization practices enhance AM colonization in D. cespitosa roots, even in soils fertilized with high rates of phosphorus.

  5. Arbuscular mycorrhiza of Deschampsia cespitosa (Poaceae at different soil depths in highly metal-contaminated site in southern Poland

    Directory of Open Access Journals (Sweden)

    Ewa Gucwa-Przepióra

    2013-12-01

    Full Text Available This study presents root colonization of Deschampsia cespitosa growing in the immediate vicinity of a former Pb/Zn smelter by arbuscular mycorhizal fungi (AMF and dark septated endophytes (DSE at different soil depths. AMF spores and species distribution in soil profile were also assessed. Arbuscular mycorrhiza (AM and DSE were found in D. cespitosa roots at all investigated soil levels. However, mycorrhizal colonization in topsoil was extremely low with sporadically occurring arbuscules. AM parameters: frequency of mycorrhization of root fragments (F%, intensity of root cortex colonization (M%, intensity of colonization within individual mycorrhizal roots (m%, and arbuscule abundance in the root system (A% were markedly higher at 20–40, 40–60 cm soil levels and differed in a statistically significant manner from AM parameters from 0–10 and 10–20 cm layers. Mycorrhizal colonization was negatively correlated with bioavailable Cd, Pb and Zn concentrations. The number of AMF spores in topsoil was very low and increased with soil depth (20–40 and 40–60 cm. At the study area spores of three morphologically distinctive AMF species were found: Archaeospora trappei, Funneliformis mosseae and Scutellospora dipurpurescens. The fourth species Glomus tenue colonized roots of D. cespitosa and was observed in the root cortex at 20–40 and 40–60 soil depth, however, its spores were not found at the site.

  6. COMPARATIVE ANALYSIS OF INTER SIMPLE SEQUENCE REPEATS AND SIMPLE SEQUENCE REPEATS MARKERS: GENETIC ANALYSIS OF DESCHAMPSIA CESPITOSA POPULATIONS GROWING IN METAL CONTAMINATED REGIONS IN CANADA

    Directory of Open Access Journals (Sweden)

    K.K. Nkongolo

    2014-01-01

    Full Text Available Comparative studies conducted on the genetic variation of metal-tolerant populations and their non-metal-tolerant counterparts have been performed on numerous species using isozyme markers. Analysis of genetic differences among plant populations growing in heavy metal-contaminated and uncontaminated regions are limited. The main objectives of the present study were to compare ISSR and microsatellite markers in assessing genetic variation in D. cespitosa populations that colonized metal-contaminated and uncontaminated regions in Northern Ontario, Canada. Total genomic DNA from D. cespitosa samples were amplified with ISSR and SSR primers using optimized PCR conditions. The level of polymorphic loci varies from 46 to 74% for ISSR analysis. The level of observed heterozygosity was moderate to high ranging from 0.44 to 0.68 for the SSR primers used. But no significant difference in genetic variation levels was detected between metal contaminated and uncontaminated sites with SSR markers. There was a significant reduction of polymorphic loci in samples from highly metal-contaminated areas of the Cobalt region compared to the reference sites based on ISSR analysis. Use of a combination of different marker systems is recommended to analyse genetic variation in plant populations.

  7. Ecotype Zones for Minnesota and Iowa Prairie Lands

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document contains a map of local ecotype seed harvest zones for Iowa and Minnesota. A local ecotype zone is defined as a geographic area with generally similar...

  8. Varied growth response of cogongrass ecotypes to elevated CO2

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    G. Brett Runion

    2016-01-01

    Full Text Available Cogongrass [Imperata cylindrica (L. P. Beauv] is an invasive C4 perennial grass which is listed as one of the top ten worst weeds in the world and is a major problem in the Southeast US. Five cogongrass ecotypes (Florida, Hybrid, Louisiana, Mobile, and North Alabama collected across the Southeast and a red-tip ornamental variety were container grown for six months in open top chambers under ambient and elevated (ambient plus 200 ppm atmospheric CO2. Elevated CO2 increased average dry weight (13% which is typical for grasses. Elevated CO2 increased height growth and both nitrogen and water use efficiencies, but lowered tissue nitrogen concentration; again, these are typical plant responses to elevated CO2. The hybrid ecotype tended to exhibit the greatest growth (followed by Louisiana, North Alabama, and Florida ecotypes while the red-tip and Mobile ecotypes were smallest. Interactions of CO2 with ecotype generally showed that the hybrid, Louisiana, Florida, and/or North Alabama ecotypes showed a positive response to CO2 while the Mobile and red-tip ecotypes did not. Cogongrass is a problematic invasive weed in the southeastern U.S. and some ecotypes may become more so as atmospheric CO2 continues to rise.

  9. Chelator profiling in Deschampsia cespitosa (L.) Beauv. Reveals a Ni reaction, which is distinct from the ABA and cytokinin associated response to Cd.

    Science.gov (United States)

    Hayward, Allison R; Coates, Kahlan E; Galer, Amy L; Hutchinson, Thomas C; Emery, R J Neil

    2013-03-01

    Plant hormones, including abscisic acid (ABA) and cytokinins (CKs), fluctuate as a result of excess metal exposure. Changes in hormonal concentration regulate plant growth and may also signal activation of metal chelators. The grass Deschampsia cespitosa was dosed with either Ni or Cd or pulsed with exogenous ABA. The roots were analyzed for ABA and CKs and for multiple potential metal chelators including: amino acids, nicotianamine (NA), and phytochelatins (PCs). They were quantified after 3 h and after 7 days, using LC-ESI MS/MS. The Ni treatment caused no measurable change in ABA or CK concentration; however, an increase in NA was documented. The Cd treatment resulted in a short-term ABA increase followed by a reduction in CKs and an increase in PC concentration. An exogenous ABA pulse in non-metal challenged plants induced changes in CKs and PCs that followed those of Cd treatment. Ni and Cd stress resulted in distinctly different detoxification responses. Since the reaction of CKs and putative metal chelators to Cd stress can be mimicked by an exogenous ABA pulse, it is suggested that ABA acts as a stress signal, resulting in reduced growth by way of decreased CK concentration and reduced metal toxicity through increased PC production.

  10. Freeze tolerance differs between two ecotypes of Paspalum vaginatum (Poaceae

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    Liliana Teresa Fabbri

    2016-03-01

    Full Text Available Morphological and physiological responses to freezing were evaluated in two ecotypes of the perennial turfgrass Paspalum vaginatum. Leaf extension rate, number of active meristems, leaf water potential and net photosynthesis were measured on plants of both a commercial cultivar, 'Sea Isle 2000', and a wild ecotype from the Flooding Pampa grasslands of Argentina. Plants were propagated by cloning, cultivated in pots, and examined during 18 consecutive days under two treatments: a non-frozen control treatment (15.5±7 ºC and a frozen treatment with two stages: Stage 1 with four hours of freezing stress for 10 nights (-5ºC, and Stage 2 with 12 hours of freezing stress for eight nights (five nights at -5ºC and three nights at -8ºC. After these treatments, plants were returned to the outside environment to evaluate shoot injury and post-freezing recovery. Leaf water potential, net photosynthesis and leaf extension rate were significantly higher in the wild ecotype than in the commercial cultivar. Meristem density was reduced after freezing in both ecotypes, but was more pronounced in the commercial cultivar (98.5% than in the wild ecotype (80%. Thus, the two ecotypes coming from different environments, exhibited different morphological and physiological responses to exposure to freezing temperatures.

  11. Edaphic factors determining variation of two ecotypes of Leymus chinensis in North China

    Institute of Scientific and Technical Information of China (English)

    ZHOU Chan; YANG Yunfei

    2006-01-01

    To identify ecotypic variation of L. chinensis, the physiological characteristics and environmental factors were measured and assessed for grey-green and yellow-green ecotypes of L. chinensis grown in the salt-alkalized and aeolian sandy soils. Although both ecotypes presented a similar salt-alkaline tolerance under the experimental conditions, they differed in several aspects. The L. chinensis grown in the aeolian sandy soils had higher water potential and chlorophyll content and lower proline content in their leaves than those grown in the salt-alkalized habitat, and the grey-green ecotype of L. chinensis in both types of soils had higher water potential,chlorophyll and proline contents than the yellow-green ecotype. Besides, grey-green ecotypes had higher salt-alkaline tolerance than the yellow-green ecotype. The stepwise regression analysis showed that soil conductance and pH value were the main ecological factors affecting the physiology of L. chinensis. From the natural distribution of the two ecotypes, we considered that salt-alkaline in the soils is the leading factor in determining ecotypic variation of L. chinensis. The two ecotypes were first named grey-green and yellow-green ecotypes respectively.

  12. Genomic evidence of adaptive evolution in emergent Vibrio parahaemolyticus ecotypes

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    Jeffrey W. Turner

    2016-07-01

    Full Text Available Abstract The ubiquitous marine bacterium Vibrio parahaemolyticus is a leading cause of illness associated with seafood consumption. The emergence of two genetically distinct ecotypes (ST3 and ST36 has led to an alarming increase in the size and frequency of disease outbreaks. We conducted a genomic comparison of 30 V. parahaemolyticus genomes that represent a diverse collection of 15 genetically distinct ecotypes, including newly sequenced representatives of ST3 and ST36, isolated from both clinical and environmental sources. A multistep evolutionary analysis showed that genes associated with sensing and responding to environmental stimuli have evolved under positive selection, identifying examples of convergent evolution between ST3 and ST36. A comparison of predicted proteomes indicated that ST3 and ST36 ecotypes laterally acquired tens of novel genes associated with a variety of functions including dormancy, homeostasis and membrane transport. Genes identified in this study play an apparent role in environmental fitness and may confer cross protection against stressors encountered in the human host. Together, these results show the evolution of stress response is an important genetic mechanism correlated with the recent emergence of the ST3 and ST36 ecotypes.

  13. Circulation of four Anaplasma phagocytophilum ecotypes in Europe

    NARCIS (Netherlands)

    Jahfari, Setareh; Coipan, E Claudia; Fonville, Manoj; van Leeuwen, Arieke Docters; Hengeveld, Paul; Heylen, Dieter; Heyman, Paul; van Maanen, Cees; Butler, Catherine M|info:eu-repo/dai/nl/304832162; Földvári, Gábor; Szekeres, Sándor; van Duijvendijk, Gilian; Tack, Wesley; Rijks, Jolianne M|info:eu-repo/dai/nl/151266093; van der Giessen, Joke; Takken, Willem; van Wieren, Sipke E; Takumi, Katsuhisa; Sprong, Hein

    2014-01-01

    BACKGROUND: Anaplasma phagocytophilum is the etiological agent of granulocytic anaplasmosis in humans and animals. Wild animals and ticks play key roles in the enzootic cycles of the pathogen. Potential ecotypes of A. phagocytophilum have been characterized genetically, but their host range,

  14. Circulation of four Anaplasma phagocytophilum ecotypes in Europe

    NARCIS (Netherlands)

    Jahfari, S.; Coipan, E.C.; Fonville, M.; Leeuwen, van A.D.; Hengeveld, P.; Heylen, D.; Heyman, P.; Maanen, van C.; Butler, C.M.; Foldvari, G.; Szekeres, S.; Duijvendijk, van L.A.G.; Tack, W.; Rijks, J.M.; Giessen, van der J.; Takken, W.; Wieren, van S.E.; Takumi, K.; Sprong, H.

    2014-01-01

    Background: Anaplasma phagocytophilum is the etiological agent of granulocytic anaplasmosis in humans and animals. Wild animals and ticks play key roles in the enzootic cycles of the pathogen. Potential ecotypes of A. phagocytophilum have been characterized genetically, but their host range,

  15. Switchgrass ecotypes alter microbial contribution to deep-soil C

    Science.gov (United States)

    Switchgrass (Panicum virgatum L.) is a C4, perennial grass that is being developed as a bioenergy crop for the United States. While aboveground biomass production is well documented for switchgrass ecotypes (lowland, upland), little is known about the impact of plant belowground productivity on mic...

  16. Circulation of four Anaplasma phagocytophilum ecotypes in Europe

    NARCIS (Netherlands)

    Jahfari, Setareh; Coipan, E Claudia; Fonville, Manoj; van Leeuwen, Arieke Docters; Hengeveld, Paul; Heylen, Dieter; Heyman, Paul; van Maanen, Cees; Butler, Catherine M; Földvári, Gábor; Szekeres, Sándor; van Duijvendijk, Gilian; Tack, Wesley; Rijks, Jolianne M; van der Giessen, Joke; Takken, Willem; van Wieren, Sipke E; Takumi, Katsuhisa; Sprong, Hein

    2014-01-01

    BACKGROUND: Anaplasma phagocytophilum is the etiological agent of granulocytic anaplasmosis in humans and animals. Wild animals and ticks play key roles in the enzootic cycles of the pathogen. Potential ecotypes of A. phagocytophilum have been characterized genetically, but their host range, zoonoti

  17. Circulation of four Anaplasma phagocytophilum ecotypes in Europe

    NARCIS (Netherlands)

    Jahfari, S.; Coipan, E.C.; Fonville, M.; Leeuwen, van A.D.; Hengeveld, P.; Heylen, D.; Heyman, P.; Maanen, van C.; Butler, C.M.; Foldvari, G.; Szekeres, S.; Duijvendijk, van L.A.G.; Tack, W.; Rijks, J.M.; Giessen, van der J.; Takken, W.; Wieren, van S.E.; Takumi, K.; Sprong, H.

    2014-01-01

    Background: Anaplasma phagocytophilum is the etiological agent of granulocytic anaplasmosis in humans and animals. Wild animals and ticks play key roles in the enzootic cycles of the pathogen. Potential ecotypes of A. phagocytophilum have been characterized genetically, but their host range, zoonoti

  18. Switchgrass ecotypes alter microbial contribution to deep-soil C

    Science.gov (United States)

    Roosendaal, Damaris; Stewart, Catherine E.; Denef, Karolien; Follett, Ronald F.; Pruessner, Elizabeth; Comas, Louise H.; Varvel, Gary E.; Saathoff, Aaron; Palmer, Nathan; Sarath, Gautam; Jin, Virginia L.; Schmer, Marty; Soundararajan, Madhavan

    2016-05-01

    Switchgrass (Panicum virgatum L.) is a C4, perennial grass that is being developed as a bioenergy crop for the United States. While aboveground biomass production is well documented for switchgrass ecotypes (lowland, upland), little is known about the impact of plant belowground productivity on microbial communities down deep in the soil profiles. Microbial dynamics in deeper soils are likely to exert considerable control on ecosystem services, including C and nutrient cycles, due to their involvement in such processes as soil formation and ecosystem biogeochemistry. Differences in root biomass and rooting characteristics of switchgrass ecotypes could lead to distinct differences in belowground microbial biomass and microbial community composition. We quantified root abundance and root architecture and the associated microbial abundance, composition, and rhizodeposit C uptake for two switchgrass ecotypes using stable-isotope probing of microbial phospholipid fatty acids (PLFAs) after 13CO2 pulse-chase labeling. Kanlow, a lowland ecotype with thicker roots, had greater plant biomass above- and belowground (g m-2), greater root mass density (mg cm-3), and lower specific root length (m g-1) compared to Summer, an upland ecotype with finer root architecture. The relative abundance of bacterial biomarkers dominated microbial PLFA profiles for soils under both Kanlow and Summer (55.4 and 53.5 %, respectively; P = 0.0367), with differences attributable to a greater relative abundance of Gram-negative bacteria in soils under Kanlow (18.1 %) compared to soils under Summer (16.3 %; P = 0.0455). The two ecotypes also had distinctly different microbial communities process rhizodeposit C: greater relative atom % 13C excess in Gram-negative bacteria (44.1 ± 2.3 %) under the thicker roots of Kanlow and greater relative atom % 13C excess in saprotrophic fungi under the thinner roots of Summer (48.5 ± 2.2 %). For bioenergy production systems, variation between switchgrass

  19. Accumulation and tolerance of lead in two contrasting ecotypes of Dianthus carthusianorum.

    Science.gov (United States)

    Wójcik, Małgorzata; Tukiendorf, Anna

    2014-04-01

    Dianthus carthusianorum is one of the dominant plant species colonising the Zn-Pb waste deposits in Bolesław, Southern Poland. It differs in terms of morphology and genetics from ecotypes inhabiting non-metal-polluted areas. The response of waste-heap (metallicolous, M) and reference (nonmetallicolous, NM) ecotypes of D. carthusianorum to Pb in hydroponics was investigated and compared in this study. The plants of the M ecotype were more tolerant to Pb than these of the NM ecotype in spite of accumulation of higher concentrations of Pb. In both ecotypes, about 70-78% of Pb was retained in roots. In non Pb-treated plants, a higher glutathione (GSH) level was found in the M ecotype. After the Pb exposure, the GSH level decreased and was similar in both ecotypes. Lead treatment induced synthesis of phytochelatins (PCs) only in the plant roots, with significantly higher concentrations thereof detected in the NM ecotype. Malate and citrate concentrations were higher in the M ecotype; however, they did not change significantly upon any Pb treatment in either ecotype. The results indicated that neither PCs nor organic acids were responsible for the enhanced Pb tolerance of the waste-heap plants.

  20. Cadmium Induced Changes of Proline in Two Ecotypes of Thlaspi Caerulescens

    Directory of Open Access Journals (Sweden)

    Zemanová V.

    2013-04-01

    Full Text Available A Thlaspi caerulescens (J. & C. PRESL was used to study the effect of cadmium on the content of free amino acids and ability accumulation of Cd in ecotypes of this plant species. In pot experiment two ecotypes T. caerulescens were used: Ganges ecotype from France and Mežica ecotype from Slovenia. The plants were grown in soil (chernozem – Suchdol spiked with NPK and three different concentration of Cd: 30, 60 and 90 mg/kg. The content of Cd was measured in the above-ground biomass and roots using ICP-OES. Accumulation of Cd was higher in the Mežica ecotype in contrast to the low Cd-accumulating the Ganges ecotype. Analyses of free amino acids contents were measured by GC-MS method. The content of free amino acids in above-ground biomass of the Mežica ecotype declined progressively with increasing concentrations of Cd. Opposite trend was observed in roots of this ecotype. The increase of free amino acids contents in above-ground biomass and roots of the Ganges ecotype were detected. The results of specific amino acids free proline showed increased content in plant biomass with increasing Cd contamination of soil. A statistically significant increase was observed between control plants (0 mg/kg Cd and variant Cd3 (90 mg/kg Cd for both ecotypes. The statistically significant decrease of free proline was observed in the Mežica ecotype roots. Opposite trend was observed in roots of Ganges ecotype - increasing trend of free proline content. These results indicate a correlation between content of Cd and content of free proline in different parts of the plant. We can speculate that the mechanism of Cd hyperaccumulation and metabolism of free proline are not identical in ecotypes of this species.

  1. WOOD ANATOMICAL STUDY AMONG THREE ECOTYPES OF Pinus merkusii IN SUMATRA AND THE POTENTIAL AS CLIMATE CHANGE INDICATOR

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    Yulia Sandri

    2016-09-01

    Full Text Available Recently, climate change is the one of most important environmental issue. Climate variability can be recorded by tree growing through the growth ring. Growth ring formed by cambial activity were examined in wood anatomy. In Sumatra, there are three ecotypes Pinus merkusii, namely ecotypes Kerinci, Tapanuli, and Aceh which can be distinguished morphologically. This study aims to knowing the wood anatomical characteristics of the three ecotypes and determine the potential as climate indicator. This study was conducted in October 2014 until June 2015. Sample of Kerinci ecotype was collected in Kerinci Seblat National Park, Tapanuli ecotype in Dolok Sibualbuali Natural Reserve and Aceh ecotype in Gunung Leuser National Park on a height of 130 cm using increment borer and cut on the main stem 5×5 cm for anatomical sample. Results from this study indicate that ecotype Kerinci and Tapanuli showed earlywood and latewood boundary exposing the clear growth ring, whereas in Aceh ecotype unclear. Tapanuli ecotype have the thickest tracheid diameter than ecotype Kerinci and Aceh. Ecotypes of Kerinci, Tapanuli, and Aceh has homoceluler and uniseriate ray where Aceh ecotype have the longest ray. Furthermore, Kerinci and Tapanuli ecotype have potential as climate indicator eventhough showed negative correlation, that Tapanuli ecotype show the best result and recommended in dendrochronology study.

  2. A genomic island linked to ecotype divergence in Atlantic cod

    DEFF Research Database (Denmark)

    Hansen, Jakob Hemmer; Eg Nielsen, Einar; Therkildsen, Nina O.;

    2013-01-01

    gene flow and large effective population sizes, properties which theoretically could restrict divergence in local genomic regions. We identify a genomic region of strong population differentiation, extending over approximately 20 cM, between pairs of migratory and stationary ecotypes examined at two......The genomic architecture underlying ecological divergence and ecological speciation with gene flow is still largely unknown for most organisms. One central question is whether divergence is genome‐wide or localized in ‘genomic mosaics’ during early stages when gene flow is still pronounced....... Empirical work has so far been limited, and the relative impacts of gene flow and natural selection on genomic patterns have not been fully explored. Here, we use ecotypes of Atlantic cod to investigate genomic patterns of diversity and population differentiation in a natural system characterized by high...

  3. Delineating ecotypes of marine photosynthetic picoeukaryotes in the wild

    Science.gov (United States)

    Limardo, A. J.; Sudek, S.; Rii, Y. M.; Church, M. J.; Wei, C. L.; Armbrust, E. V.; Worden, A. Z.

    2015-12-01

    Extremely small eukaryotic green algae are abundant primary producers found in diverse marine habitats. Over the last decade several studies have revealed extensive diversity within the "pico-prasinophytes" (≤2 µm diameter) that was previously unrecognized due to a lack of distinguishing morphological features. Using whole genome and marker gene analyses, distinct species have since been recognized within the Micromonas and Ostreococcus genera. Relatively little is known about environmental factors driving distributions of these species, but for Ostreococcus, laboratory studies suggested that differentiation reflects high- and low-light adapted ecotypes. Subsequent field studies indicated that Ostreococcus Clade OI and Clade OII rarely co-occur but partition according to distinct habitats - representing 'mesotrophic' and 'oligotrophic' ecotypes, respectively. Unlike Micromonas and Ostreococcus, Bathycoccus was presumed to be a single cosmopolitan species because identical 18S rRNA gene sequences are observed in cultured isolates and in environmental surveys. However, analysis of a targeted metagenome from a Bathycoccus population in the tropical Atlantic led to the hypothesis that Bathycoccus also harbors distinct ecotypes. Here, we have developed qPCR assays to enumerate the two Bathycoccus types which can be discriminated based on the internal transcribed spacer (ITS). Statistical analysis of qPCR and environmental data from >200 North Pacific Ocean samples shows that the two Bathycoccus clades are only somewhat analogous to oligotrophic and mesotrophic Ostreococcus clades. The two Bathycoccus clades co-occurred more than twice as often as the Ostreococcus clades. Additionally, while Bathycoccus BII and oligotrophic Ostreococcus OII were found at warm temperatures up to 26°C, BII extended into colder waters than OII. Similarly, Bathycoccus BI extended into warmer waters than mesotrophic Ostreococcus OI. Currently, we are analyzing metatranscriptomes to

  4. Accuracy and efficiency of algorithms for the demarcation of bacterial ecotypes from DNA sequence data.

    Science.gov (United States)

    Francisco, Juan Carlos; Cohan, Frederick M; Krizanc, Danny

    2014-01-01

    Identification of closely related, ecologically distinct populations of bacteria would benefit microbiologists working in many fields including systematics, epidemiology and biotechnology. Several laboratories have recently developed algorithms aimed at demarcating such 'ecotypes'. We examine the ability of four of these algorithms to correctly identify ecotypes from sequence data. We tested the algorithms on synthetic sequences, with known history and habitat associations, generated under the stable ecotype model and on data from Bacillus strains isolated from Death Valley where previous work has confirmed the existence of multiple ecotypes. We found that one of the algorithms (ecotype simulation) performs significantly better than the others (AdaptML, GMYC, BAPS) in both instances. Unfortunately, it was also shown to be the least efficient of the four. While ecotype simulation is the most accurate, it is by a large margin the slowest of the algorithms tested. Attempts at improving its efficiency are underway.

  5. Distribution and diversity of Prochlorococcus ecotypes in the Red Sea

    KAUST Repository

    Shibl, Ahmed A.

    2014-06-19

    Photosynthetic prokaryotes of the genus Prochlorococcus play a major role in global primary production in the world\\'s oligotrophic oceans. A recent study on pelagic bacterioplankton communities in the northern and central Red Sea indicated that the predominant cyanobacterial 16S rRNA gene sequence types were from Prochlorococcus cells belonging to a high-light-adapted ecotype (HL II). In this study, we analyzed microdiversity of Prochlorococcus sp. at multiple depths within and below the euphotic zone in the northern, central, and southern regions of the Red Sea, as well as in surface waters in the same locations, but in a different season. Prochlorococcus dominated the communities in clone libraries of the amplified 16S-23S rRNA internal transcribed spacer (ITS) region. Almost no differences were found between samples from coastal or open-water sites, but a high diversity of Prochlorococcus ecotypes was detected at 100-meter depth in the water column. In addition, an unusual dominance of HL II-related sequences was observed in deeper waters. Our results indicate that the Red Sea harbors diverse Prochlorococcus lineages, but no novel ecotypes, despite its unusual physicochemical properties. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  6. Recurrent evolution of life history ecotypes in sockeye salmon: implications for conservation and future evolution.

    Science.gov (United States)

    Wood, Chris C; Bickham, John W; John Nelson, R; Foote, Chris J; Patton, John C

    2008-05-01

    We examine the evolutionary history and speculate about the evolutionary future of three basic life history ecotypes that contribute to the biocomplexity of sockeye salmon (Oncorhynchus nerka). The 'recurrent evolution' (RE) hypothesis claims that the sea/river ecotype is ancestral, a 'straying' form with poorly differentiated (meta)population structure, and that highly structured populations of lake-type sockeye and kokanee have evolved repeatedly in parallel adaptive radiations between recurrent glaciations of the Pleistocene Epoch. Basic premises of this hypothesis are consistent with new, independent evidence from recent surveys of genetic variation in mitochondrial and microsatellite DNA: (1) sockeye salmon are most closely related to pink (O. gorbuscha) and chum (O. keta) salmon with sea-type life histories; (2) the sockeye life history ecotypes exist as polyphyletic lineages within large drainages and geographic regions; (3) the sea/river ecotype exhibits less genetic differentiation among populations than the lake or kokanee ecotypes both within and among drainages; and (4) genetic diversity is typically higher in the sea/river ecotype than in the lake and kokanee ecotypes. Anthropogenic modification of estuarine habitat and intensive coastal fisheries have likely reduced and fragmented historic metapopulations of the sea/river ecotype, particularly in southern areas. In contrast, the kokanee ecotype appears to be favoured by marine fisheries and predicted changes in climate.

  7. Physiological assessment of drought tolerance of two ecotypes of cumin (Cuminum cyminum L. under greenhouse conditions

    Directory of Open Access Journals (Sweden)

    2015-11-01

    Full Text Available Drought has adverse effects on plant growth and production. Plants respond to drought stress through biochemical and physiological processes. In the present study, physiological responses of two cumin (Cuminum cyminum L. ecotypes including Ravar and Gonbad, which belong to dry and sub-humid regions of Iran, respectively, were evaluated in a split-plot factorial experiment with three replications in controlled greenhouse conditions. Physiological traits such as relative water content, relative leaf water loss and electrolyte leakage were measured. Analysis of variance showed that there are considerable genetic variations for drought tolerance between the ecotypes. Drought stress decreased relative water content and relative leaf water loss rate, while electrolyte leakage was significantly increased in both ecotypes. Most of the significant changes were recorded in Gonbad ecotype. The Ravar ecotype demonstrated higher tolerance to drought stress, as compared to Gonbad ecotype, which can be due to compatibility of this genotype to water-deficit conditions. Therefore, this ecotype was recommended as a tolerant ecotype to drought stress. In conclusion, the investigated traits in this experiment were found to be valuable criteria in selection of drought-tolerant ecotypes at seedling stage under greenhouse conditions.

  8. The adaptive value of phenotypic plasticity in two ecotypes of a marine gastropod

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    Butlin Roger K

    2010-10-01

    Full Text Available Abstract Background Few surveys have concentrated on studying the adaptive value of phenotypic plasticity within genetically-distinct conspecific ecotypes. Here, we conduct a test to assess the adaptive value that partial phenotypic plasticity may have for survival in the marine gastropod Littorina saxatilis. This species has evolved canalized ecotypes but, nevertheless, the ecotypes show some phenotypic plasticity for the traits under divergent selection between wave-exposed and high-predation habitats. Results We exposed juveniles of each ecotype to several environmental treatments under laboratory conditions in order to produce shape variation associated with plasticity. The two ecotypes from different treatments were then transplanted to the wave-exposed habitat and the survival rate was monitored. Ecotype explained the largest distinction in survival rate while treatment caused variation in survival rate within the ecotype released into its parental habitat which was correlated with plastic changes in shell shape. Snails that had experienced a treatment mimicking the environment of the transplantation location survived with the highest rate, while individuals from the contrary experimental treatment had lower survivorship. Conclusions We conclude that the partial plastic response shown in Littorina saxatilis has a significant impact on fitness, although this remains small compared to the overall adaptive difference between ecotypes.

  9. [Effects of exogenous Ca2+ on the growth and Zn accumulation of two Sedum alfredii Hance ecotypes].

    Science.gov (United States)

    Huang, Hua-gang; Li, Ting-xuan; Zhang, Xi-zhou; Tian, Sheng-ke; Yang, Xiao-e

    2008-04-01

    A hydroponic study was conducted to investigate the biomass, root morphology, and zinc (Zn), calcium (Ca) and sulfur (S) contents of two Sedum alfredii ecotypes under effects of different concentration calcium (Ca2+) addition. The results showed that with increasing exogenous Ca2+ concentration, the dry mass of the two S. alfredii ecotypes increased, and the shoot dry mass of hyperaccumulation ecotype increased significantly (P hyperaccumulation ecotype increased with increasing exogenous Ca2+ concentration, while those of non-hyperaccumulation ecotype were in adverse. The Zn accumulation in the root, stem and leaf of hyperaccumulation ecotype was increased with increasing exogenous Ca2+ concentration though the differences among Ca2+ treatments were not significant (P >0.05), while the Zn accumulation in the shoot of non-hyperaccumulation ecotype was significantly low (P hyperaccumulation ecotype had a significant positive correlation with the concentration of exogenous Ca2+ (P hyperaccumulation ecotype (P hyperaccumulation ecotype, while inhibited the Zn accumulation of non-hyperaccumulation ecotype. Appropriate concentration of exogenous Ca2+ could promote the growth of hyperaccumulation ecotype S. alfredii, and improve its ability of accumulating more zinc.

  10. [Quality variation and ecotype division of Panax quinquefolium in China].

    Science.gov (United States)

    Huang, Lin-Fang; Suo, Feng-Mei; Song, Jing-Yuan; Wen, Mei-Jia; Jia, Guang-Lin; Xie, Cai-Xiang; Chen, Shi-Lin

    2013-04-01

    Quality variation and ecotype classification of Chinese herbal medicine are important scientific problems in Daodi herbal medicine research. The diversity of natural environmental conditions has led to form unique multi-Daodi, multi-product areas that produce particular Chinese herbal medicine. China is one of three big American ginseng (Panax quinquefolium L.) producing areas worldwide, with over 300 years of application and 40 years of cultivation history. Long-term production practice has led to the formation of three big advocate produce areas in China: Northeast province, Beijing and Shandong. P. quinquefolium L. grown under certain environmental conditions will develop long-term adaptations that will lead to more stable strains (different ecotypes). P. quinquefolium L., can vary greatly in quality; however, the ecological mechanisms causing this variation are still unclear. Root samples were collected from four-year-old cultivated P. quinquefolium L. plants in the three major genuine (Daodi) American ginseng-producing areas of Northeast province, Beijing and Shandong province, China. Ultra-performance liquid chromatography was used to analyze the contents of eight ginsenosides (Rg1, Re, Rb1, Rb2, Rb3, Rc, Rd, Rg2). Data for nine ecological factors, including temperature, moisture and sunlight, were obtained from the ecological database of Geographic Information System for Traditional Chinese Medicine. Soil samples from the sampling sites were collected. Effective boron and iron, available nitrogen and potassium, as well as other trace elements and soil nutrients, were determined by conventional soil physicochemical property assay methods. Analytical methods of biostatistics and numerical taxonomy were used to divide ecotypes of the three main Panax quinquefolium L. producing areas in China based on ginsenoside content, climate, soil and other ecological factors. To our knowledge, this is the first time that ecological division of P. quinquefolium L. producing

  11. Reproductive, morphological, and phytochemical responses of Arabidopsis thaliana ecotypes to enhanced UV-B radiation

    Energy Technology Data Exchange (ETDEWEB)

    Trumbull, V.L.; McCloud, E.S.; Paige, K.N. (Univ. of Illinois, Urbana, IL (United States))

    1994-06-01

    Two ecotypes of Arabidopsis thaliana, collected from Libya and Norway, were grown in the greenhouse under. UV-B doses of 0 and 10.5 kJ m[sup [minus]2] UV-B[sub BE]. The high UV-B dose simulated midsummer ambient conditions over Libya and a 40% reduction in stratospheric ozone over Norway. The Libyan ectotype, which originated from latitudes where solar UV-B is high, showed no UV-B induced damage to plant growth. However the Norwegian ecotype, which originated from latitudes where solar UV-B is low, showed a significant reduction in plant height, inflorescence weight, and rosette weight in response to enhanced UV-B. Although fruit and seed number for both ecotypes were unaffected by enhanced UV-B radiation the germination success of the seeds harvested from the irradiated Norwegian plants were significantly reduced. The two ecotypes also differed with respect to their accumulation of kaempferol, a putative UV-B protective filter. The Libyan ecotype increased kaempferol concentration by 38% over the 0 kJ treatment whereas the Norwegian ecotype increased by only 15%. These data suggest that, for these ecotypes, variation in UV-B sensitivity may be explained by the differential induction of UV-absorbing leaf pigments.

  12. Genetic Diversity Analysis of Iranian Jujube Ecotypes (Ziziphus spp. Using RAPD Molecular Marker

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    S Abbasi

    2012-12-01

    Full Text Available Jujube (Ziziphus jujuba Mill. is a valuable medicinal plant which is important in Iranian traditional medicines. Although the regional plants such as jujube play an important role in our economy, but they are forgotten in research and technology. Considering the economic and medicinal importance of jujube, the first step in breeding programs is determination of the genetic diversity among the individuals. 34 ecotypes of jujube, which have been collected from eight provinces of Iran, were used in this study. The genetic relationships of Iranian jujube ecotypes were analyzed using Random Amplified Polymorphic DNA (RAPD marker. Six out of 15 random decamer primers applied for RAPD analysis, showed an informative polymorphism. According to clustering analysis using UPGMA's methods, the ecotypes were classified into two major groups at the 0.81 level of genetic similarity. The highest value of similarity coefficient (0.92 was detected between Mazandaran and Golestan ecotypes and the most genetic diversity was observed in ecotypes of Khorasan-Jonoubi. The affinity of Khorasan-Jonoubi and Esfahan ecotypes indicated a possible common origin for the variation in these areas. Results indicated that RAPD analysis could be successfully used for the estimation of genetic diversity among Ziziphus ecotypes and it can be useful for further investigations.

  13. Shared and nonshared genomic divergence in parallel ecotypes of Littorina saxatilis at a local scale.

    Science.gov (United States)

    Ravinet, Mark; Westram, Anja; Johannesson, Kerstin; Butlin, Roger; André, Carl; Panova, Marina

    2016-01-01

    Parallel speciation occurs when selection drives repeated, independent adaptive divergence that reduces gene flow between ecotypes. Classical examples show parallel speciation originating from shared genomic variation, but this does not seem to be the case in the rough periwinkle (Littorina saxatilis) that has evolved considerable phenotypic diversity across Europe, including several distinct ecotypes. Small 'wave' ecotype snails inhabit exposed rocks and experience strong wave action, while thick-shelled, 'crab' ecotype snails are larger and experience crab predation on less exposed shores. Crab and wave ecotypes appear to have arisen in parallel, and recent evidence suggests only marginal sharing of molecular variation linked to evolution of similar ecotypes in different parts of Europe. However, the extent of genomic sharing is expected to increase with gene flow and more recent common ancestry. To test this, we used de novo RAD-sequencing to quantify the extent of shared genomic divergence associated with phenotypic similarities amongst ecotype pairs on three close islands (<10 km distance) connected by weak gene flow (Nm ~ 0.03) and with recent common ancestry (<10 000 years). After accounting for technical issues, including a large proportion of null alleles due to a large effective population size, we found ~8-28% of positive outliers were shared between two islands and ~2-9% were shared amongst all three islands. This low level of sharing suggests that parallel phenotypic divergence in this system is not matched by shared genomic divergence despite a high probability of gene flow and standing genetic variation.

  14. Evaluation of Freezing Tolerance of Three Ajowan (Trachyspermum ammi (Linn. Sprague Ecotypes in Controlled Conditions

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    Z Boroumand Rezazadeh

    2013-08-01

    Full Text Available Ajowan is one of the endemic plants in Khorasan province, and there is a little information on its tolerance to cold stress. In order to study freezing tolerance of ajowan, an experiment was conducted in faculty of agriculture, Ferdowsi University of Mashhad, based on factorial-completely randomized design with three replications and three ecotypes of ajowan (Neishabour, Birjand and Torbat-e-Heidarieh were imposed on eight freezing temperatures (0 (control, -1.5, -3, -4.5, -6,-7.5, -9 and -10.5 °C. Plants were grown in natural environment till 4-5 leaf stage, then for freezing treatments transferred to thermo-gradient freezer. The cell membrane stability was evaluated by electrolyte leakage index (EL and temperature for killing 50% of samples according to the electrolyte leakage (LT50el was determined. Furthermore, survival percentage, leaf number and dry weight, temperature for killing 50% of samples according to survival (LT50su and reduced dry matter temperature 50 (RDMT50 were determined after three weeks recovery in the glasshouse. Response of ajowan ecotypes for electrolyte leakage was different and birjand ecotype had the lowest %EL, whereas the slope of %EL in mentioned ecotype was lower than two other ecotypes. However there were no significant differences among ajowan ecotypes on LT50su. Decreasing temperature to -7.5 °C reduced survival percentage of Neishabour and Torbat-e-Heidarieh ecotypes to lower than 20 percent, whiles in this temperature Birjand’s survival percentage was about 60 percent. It seems that Birjand ecotype with the lowest electrolyte leakage, the highest survival and dry matter and the lowest LT50su was more tolerant than two other ecotypes.

  15. The effect of Chinese tallow tree (Sapium sebiferum) ecotype on soil-plant system carbon and nitrogen processes.

    Science.gov (United States)

    Zou, Jianwen; Rogers, William E; DeWalt, Saara J; Siemann, Evan

    2006-11-01

    The EICA hypothesis predicts that shifts in allocation of invasive plants give rise to higher growth rates and lower herbivore defense levels in their introduced range than conspecifics in their native range. These changes in traits of invasive plants may also affect ecosystem processes. We conducted an outdoor pot experiment with Chinese tallow tree (Sapium sebiferum, Euphorbiaceae) seedlings from its native (Jiangsu, China, native ecotype) and introduced ranges (Texas, USA, invasive ecotype) to compare their relative performances in its native range and to examine ecotype effects on soil processes with and without fertilization. Consistent with predictions, plant (shoot and root) mass was significantly greater and leaf defoliation tended to be higher, while the root:shoot ratio was lower for the invasive ecotype relative to the native ecotype. Seasonal amounts of soil-plant system CO(2) and N(2)O emissions were higher for the invasive ecotype than for the native ecotype. Soil respiration rates and N(2)O emission increases from fertilization were also greater for the invasive ecotype than for the native ecotype, while shoot-specific respiration rates (g CO(2)-C g(-1) C day(-1)) did not differ between ecotypes. Further, soil inorganic N (ammonium and nitrate) was higher, but soil total N was lower for soils with the invasive ecotype than soils with the native ecotype. Compared with native ecotypes, therefore, invasive ecotypes may have developed a competition advantage in accelerating soil processes and promoting more nitrogen uptake through soil-plant direct interaction. The results of this study suggest that soil and ecosystem processes accelerated by variation in traits of invasive plants may have implications for their invasiveness.

  16. Phylogenomics of the killer whale indicates ecotype divergence in sympatry.

    Science.gov (United States)

    Moura, A E; Kenny, J G; Chaudhuri, R R; Hughes, M A; Reisinger, R R; de Bruyn, P J N; Dahlheim, M E; Hall, N; Hoelzel, A R

    2015-01-01

    For many highly mobile species, the marine environment presents few obvious barriers to gene flow. Even so, there is considerable diversity within and among species, referred to by some as the 'marine speciation paradox'. The recent and diverse radiation of delphinid cetaceans (dolphins) represents a good example of this. Delphinids are capable of extensive dispersion and yet many show fine-scale genetic differentiation among populations. Proposed mechanisms include the division and isolation of populations based on habitat dependence and resource specializations, and habitat release or changing dispersal corridors during glacial cycles. Here we use a phylogenomic approach to investigate the origin of differentiated sympatric populations of killer whales (Orcinus orca). Killer whales show strong specialization on prey choice in populations of stable matrifocal social groups (ecotypes), associated with genetic and phenotypic differentiation. Our data suggest evolution in sympatry among populations of resource specialists.

  17. Phenotypic plasticity in response to the social environment: effects of density and sex ratio on mating behaviour following ecotype divergence.

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    Kristina Karlsson

    Full Text Available The ability to express phenotypically plastic responses to environmental cues might be adaptive in changing environments. We studied phenotypic plasticity in mating behaviour as a response to population density and adult sex ratio in a freshwater isopod (Asellus aquaticus. A. aquaticus has recently diverged into two distinct ecotypes, inhabiting different lake habitats (reed Phragmites australis and stonewort Chara tomentosa, respectively. In field surveys, we found that these habitats differ markedly in isopod population densities and adult sex ratios. These spatially and temporally demographic differences are likely to affect mating behaviour. We performed behavioural experiments using animals from both the ancestral ecotype ("reed" isopods and from the novel ecotype ("stonewort" isopods population. We found that neither ecotype adjusted their behaviour in response to population density. However, the reed ecotype had a higher intrinsic mating propensity across densities. In contrast to the effects of density, we found ecotype differences in plasticity in response to sex ratio. The stonewort ecotype show pronounced phenotypic plasticity in mating propensity to adult sex ratio, whereas the reed ecotype showed a more canalised behaviour with respect to this demographic factor. We suggest that the lower overall mating propensity and the phenotypic plasticity in response to sex ratio have evolved in the novel stonewort ecotype following invasion of the novel habitat. Plasticity in mating behaviour may in turn have effects on the direction and intensity of sexual selection in the stonewort habitat, which may fuel further ecotype divergence.

  18. ABSCISIC ACID EFFECTS ON WATER AND PHOTOSYNTHETIC CHARACTERISTICS OF TWO ECOTYPES OF Atriplex halimus L.

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    Y. Bidai

    2016-05-01

    Full Text Available The aim of this study is to compare the water and photosynthetic characteristics of two xerophilic ecotypes of Atriplex halimus (L.. Seeds collected from two different sites Djelfa and Oran are germinated in controlled greenhouse. After 6 months, the plantlets were treated 21 days with increasing concentrations of abscisic acid (0M, 10-6 M and 10-3 M. The results show that ecotype of Djelfa reduced water loss through transpiration because of high stomatal resistance. Consequently the content of chlorophyll a and b decrease significantly compared to Oran ecotype which show an increase of the osmotic potential and relative water content. Osmotic adjustment to reduce dehydration and maintain a good photosynthesis seems efficient in Oran ecotype.

  19. Genetic and Ecotypic Differentiation in a Californian Plant Polyploid Complex (Grindelia, Asteraceae)

    OpenAIRE

    Abigail J Moore; Moore, William L.; Baldwin, Bruce G.

    2014-01-01

    Studies of ecotypic differentiation in the California Floristic Province have contributed greatly to plant evolutionary biology since the pioneering work of Clausen, Keck, and Hiesey. The extent of gene flow and genetic differentiation across interfertile ecotypes that span major habitats in the California Floristic Province is understudied, however, and is important for understanding the prospects for local adaptation to evolve or persist in the face of potential gene flow across populations...

  20. Demographic characteristics of circumpolar caribou populations: ecotypes, ecological constraints, releases, and population dynamics

    OpenAIRE

    Mallory, F.F.; T.L. Hillis

    1998-01-01

    Data on the status of caribou {Rangifer tarandus) herds throughout the circumpolar region during the last 20 years were obtained from the literature and personal communication with researchers. Information was analysed in relation to ecotype (insular, montane, barren-ground, and woodland/forest), population status (increasing, stable, decreasing), herd size, human impact, and temporal change in number. The data support the conclusions (1) that each ecotype is exposed to different ecological c...

  1. Identification and Selection for Salt Tolerance in Alfalfa (Medicago sativa L. Ecotypes via Physiological Traits

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    Hassan MONIRIFAR

    2009-12-01

    Full Text Available Salt stress is a serious environmental problem throughout the world which may be partially relieved by breeding cultivars that can tolerate salt stress. Plant breeding may provide a relatively cost effective short-term solution to the salinity problem by producing cultivars able to remain productive at low to moderate levels of salinity. Five alfalfa cultivars, �Seyah-Roud�, �Ahar-Hourand�, �Oskou�, �Malekan� and �Sefida-Khan� were assessed for salt tolerance at mature plant stage. A greenhouse screening system was used to evaluate individual alfalfa plants grown in perlit medium, and irrigated with water containing different amounts of NaCl. Three salt levels were achieved by adding 0, 100 and 200 mM NaCl to Hoagland nutrient solution, respectively. Forage yield, sodium and potassium contents and K/Na ratio was determined. Also, leaf samples were analyzed for proline and chlorophyll contents. The ecotypes Seyha-Roud and �Sefida-Khan� had comparatively less sodium contents than �Oskou�, �Ahar-Hourand� and �Malekan� ecotypes, also potassium content increased under saline condition. Forage yield of different alfalfa ecotypes was significantly influenced by the salinity. The ecotypes �Malekan�, Ahar- Hourand and �Oskou� were successful in maintaining forage yield under salinity stress. Sodium contents increased due to salinity in all alfalfa ecotypes however ecotypes �Ahar-Hourand� and �Malekan� maintained the highest leaf Na concentration. They showed higher content of K than other ecotypes but had lower K/Na ratio. It was concluded that, two ecotypes �Malekan� and �Ahar-Hourand� were better.

  2. Genetic diversity in South African Nguni cattle ecotypes based on microsatellite markers.

    Science.gov (United States)

    Sanarana, Yandisiwe; Visser, Carina; Bosman, Lydia; Nephawe, Khathutshelo; Maiwashe, Azwihangwisi; van Marle-Köster, Este

    2016-02-01

    The Nguni cattle breed is a landrace breed adapted to different ecological regions of South Africa. A number of ecotypes are recognised based on phenotype within the breed, but it is not known if they are genetically distinct. In this study, molecular characterisation was performed on Makhathini (MAK), Pedi (PED), Shangaan (SHA) and Venda (VEN) Nguni cattle ecotypes. Two Nguni cattle populations, not kept as separate ecotypes, from the University of Fort Hare (UFH) and Agricultural Research Council Loskop South farm (LOS) were also included. Genotypic data was generated for 189 unrelated Nguni cattle selected based on pedigree records using 22 microsatellite markers. The expected heterozygosity values varied from 69 % (UFH) to 72 % (PED) with a mean number of alleles ranging from 6.0 to 6.9. The F ST estimate demonstrated that 4.8 % of the total genetic variation was due to the genetic differentiation between the populations and 92.2 % accounted for differences within the populations. The genetic distances and structure analysis revealed the closest relationship between MAK, PEDI and SHA ecotypes, followed by SHA and VEN. The UFH population clustered with the MAK ecotype, indicating that they are more genetically similar, while the LOS cattle grouped as a distinct cluster. Results suggest that the genetic differentiation between the PED and SHA ecotypes is low and can be regarded as one ecotype based on limited genetic differences. The results of this study can be applied as a point of reference for further genetic studies towards conservation of Nguni cattle ecotypes.

  3. Microsatellite based genetic diversity study in indigenous chicken ecotypes of Karnataka

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    B. H. Rudresh

    2015-08-01

    Full Text Available Aim: The current study was the first of its kind taken upon indigenous ecotypes of the Karnataka in order to unravel the diversity details at 20 chicken microsatellite regions. Materials and Methods: 210 indigenous chicken belonging to six districts of Bangalore and Mysore division formed the target sample for the present study. The genomic deoxyribonucleic acid was isolated by phenol chloroform isoamyl alcohol method. A panel of 20 microsatellite regions, including 14 recommended by FAO and six identified from published scientific literature became the targeted chicken genomic region. 27-33 samples were successfully genotyped in each of the six ecotypes through simplex or multiplex polymerase chain reactions, polyacrylamide gel electrophoresis and silver staining for the selected microsatellite panel. Results: The chickens of Ramanagara and Chamrajnagara were most distant with a Nei’s genetic distance value of 0.22. The chickens of Bangalore rural and Mysore were least distant with a value of 0.056. The Ramanagara and Chamrajnagara pair had Nei’s genetic identity value of 0.802, which is least among all pairs of ecotypes. There were five main nodes from which the six ecotypes evolved on the basis 20 microsatellite markers used in this study. This study indicates that the four ecotypes Ramnagara, Bangalore Rural, Chickaballapura and Mysore are genetically identical due to their common ancestral evolution while, Mandya and Chamrajnagara ecotypes formed a relatively different cluster due to a separate common ancestral chicken population and less number of generations since drifting from bifurcation node. Conclusion: Twenty microsatellite markers based genetic diversity study on six indigenous ecotypes indicated lower genetic distances as well as lower FST values compared to the distinguished breeds reported. There were two main clusters, which differentiated into six ecotypes. They may differentiate into more distinct varieties if bred in

  4. Brood development of different carniolan bee ecotypes (Apis mellifera carnica Pollmann, 1879

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    Dragan Bubalo

    2002-09-01

    Full Text Available Brood development of different carniolan honeybee ecotypes (Apis mellifera carnica Pollmann, 1879 was carried out in condition of pannonian and alpine climate. The colonies on both experimental apiaries were divided in the three groups, each 12 queens, of alpine (Austria, subalpine (Slovenia and pannonian (Croatia ecotype. The experiment was designed to monitor development of brood, the total number of laid cells and colony strength. In particular part of the year, experimental ecotypes shown significant differences in area of unsealed and sealed brood in both climate. In the whole season there was not established significant difference between ecotypes regarding to development of drone brood. In pannonian climate, in comparison to alpine climate, the number of laid eggs was higher for all ecotypes. Pannonian ecotype did not recognize all food sources in the new environment, which could be seen in the lack of pollen in the colonies at the alpine climate during last two measuriments. The lack of pollen affected the weakening of the colonies laiter in the season.

  5. COMPARISON OF SLAUGHTER, CARCASS VALUES OF SUDAN GOAT ECOTYPES FED DIFFERENT LEVELS OF ENERGY/PROTEIN

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    A.A. TAMEEM ELDAR

    2012-07-01

    Full Text Available This experiment aimed to assess the slaughter and carcass values of different Sudan goat ecotypes (Nubian, Desert and Swiss Nubian fed different levels of energy/protein. Nine male goat kids (2-3 months and average weight 9.23 kg of either ecotypes were used in a 3x3x3 arrangement, fed three experimental diets A (control, B and C, with varying energy: protein 1:0.14, 1:0.16 and 1:0.18 respectively. The study showed that Nubian goats possessed heavier slaughter weight; empty body weight, warm and cold carcass weight than the Desert and Swiss Nubian goats in the ration B and C. Dressing percentage on both basis (slaughter weight and empty body weight of Nubian were higher for ration B and C. Warm carcass weights of all goat ecotypes increased directly with energy: protein ratio. Highest weight of leg, loin, rack and neck and shoulder were recorded by Nubian goats for ration B and C. It was concluded that, all ecotype kids respond well to increasing energy protein levels. According to the results obtained local goat ecotypes, mainly Nubian goats, responded well to improved nutrition, therefore results obtained can be applied for the local goat ecotypes studied to encourage goat meat consumption and exportation.

  6. Comparison of seasonal habitat selection between threatened woodland caribou ecotypes in central British Columbia

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    Elena S. Jones

    2007-04-01

    Full Text Available Woodland caribou (Rangifer tarandus caribou in British Columbia have been classified into ecotypes based on differences in use of habitat in winter. Although recovery planning focuses on ecotypes, habitat use and selection varies within ecotypes. Our objectives were to compare habitat use and selection among previously identified woodland caribou herds at the transition zone between northern (Moberly, Quintette, and Kennedy herds and mountain (Parsnip herd ecotypes in central British Columbia. We developed selection models for each herd in spring, calving, summer/fall, early and late winter. Topographic models best predicted selection by most herds in most seasons, but importance of vegetation-cover was highlighted by disproportionate use of specific vegetation-cover types by all caribou herds (e.g., in early winter, 75% of Kennedy locations were in pine-leading stands, 84% of Parsnip locations were in fir and fir-leading stands, and 87 and 96% of locations were in alpine for the Moberly and Quintette herds, respectively. Using a combination of GPS and VHF radio-collar locations, we documented some spatial overlap among herds within the year, but use of vegetation-cover types and selection of elevations, aspects, and vegetation-cover types differed among herds and within ecotypes in all seasons. Habitat use and selection were most similar between the two northern-ecotype herds residing on the eastern side of the Rocky Mountains. This research indicates that habitat use and selection by caribou herds in all seasons is more variable than ecotype classifications suggest and demonstrates the value of undertaking herd-specific mapping of critical habitat for woodland caribou.

  7. Replaying Evolution to Test the Cause of Extinction of One Ecotype in an Experimentally Evolved Population.

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    Caroline B Turner

    Full Text Available In a long-term evolution experiment with Escherichia coli, bacteria in one of twelve populations evolved the ability to consume citrate, a previously unexploited resource in a glucose-limited medium. This innovation led to the frequency-dependent coexistence of citrate-consuming (Cit+ and non-consuming (Cit- ecotypes, with Cit-bacteria persisting on the exogenously supplied glucose as well as other carbon molecules released by the Cit+ bacteria. After more than 10,000 generations of coexistence, however, the Cit-lineage went extinct; cells with the Cit-phenotype dropped to levels below detection, and the Cit-clade could not be detected by molecular assays based on its unique genotype. We hypothesized that this extinction was a deterministic outcome of evolutionary change within the population, specifically the appearance of a more-fit Cit+ ecotype that competitively excluded the Cit-ecotype. We tested this hypothesis by re-evolving the population from a frozen population sample taken within 500 generations of the extinction and from another sample taken several thousand generations earlier, in each case for 500 generations and with 20-fold replication. To our surprise, the Cit-type did not go extinct in any of these replays, and Cit-cells also persisted in a single replicate that was propagated for 2,500 generations. Even more unexpectedly, we showed that the Cit-ecotype could reinvade the Cit+ population after its extinction. Taken together, these results indicate that the extinction of the Cit-ecotype was not a deterministic outcome driven by competitive exclusion by the Cit+ ecotype. The extinction also cannot be explained by demographic stochasticity alone, as the population size of the Cit-ecotype should have been many thousands of cells even during the daily transfer events. Instead, we infer that the extinction must have been caused by a rare chance event in which some aspect of the experimental conditions was inadvertently perturbed.

  8. Metabolic and biological profile of autochthonous Vitis vinifera L. ecotypes.

    Science.gov (United States)

    Impei, Stefania; Gismondi, Angelo; Canuti, Lorena; Canini, Antonella

    2015-05-01

    Vitis vinifera L. is a plant species rich in phenolic compounds that are usually associated with the health benefits of wine and grape consumption in the diet. Anthocyanins, catechins, flavonol, phenolic acids and stilbenes are key molecular constituents of the Vitis berries, affecting the quality of grape products. The purpose of this work was to identify the metabolic profiles of 37 genetically certified V. vinifera Latial accessions. In particular, qualitative and quantitative analyses of specific secondary metabolites and total phenolic and tannin contents were performed by LC-MS and spectrophotometric analysis. In addition, since plant molecules are well-known for their free radical scavenging properties, the antioxidant effects of the sample extracts were evaluated through two different antiradical assays: DPPH and FRAP tests. Finally, a preliminary screening of the antiproliferative activity of each specimen on HCT-116 human colorectal cancer cells was conducted. All the results showed a great variety and amount of phenolic compounds in all accessions; moreover, we observed a significant correlation in the extracts between the metabolite concentration and bioactivity. Besides, some samples presented extraordinary biological effects, such as reduction of tumor cell growth not associated with cytotoxicity, supporting their use as possible future adjuvants for cancer therapy. In conclusion, the present research increased the scientific knowledge about Italian autochthonous vine ecotypes in order to valorize them and support their reintroduction in the local economic system.

  9. Divergence is focused on few genomic regions early in speciation: incipient speciation of sunflower ecotypes.

    Science.gov (United States)

    Andrew, Rose L; Rieseberg, Loren H

    2013-09-01

    Early in speciation, as populations undergo the transition from local adaptation to incipient species, is when a number of transient, but potentially important, processes appear to be most easily detected. These include signatures of selective sweeps that can point to asymmetry in selection between habitats, divergence hitchhiking, and associations of adaptive genes with environments. In a genomic comparison of ecotypes of the prairie sunflower, Helianthus petiolaris, occurring at Great Sand Dunes National Park and Preserve (Colorado), we found that selective sweeps were mainly restricted to the dune ecotype and that there was variation across the genome in whether proximity to the nondune population constrained or promoted divergence. The major regions of divergence were few and large between ecotypes, in contrast with an interspecific comparison between H. petiolaris and a sympatric congener, Helianthus annuus. In general, the large regions of divergence observed in the ecotypic comparison swamped locus-specific associations with environmental variables. In both comparisons, regions of high divergence occurred in portions of the genetic map with high marker density, probably reflecting regions of low recombination. The difference in genomic distributions of highly divergent regions between ecotypic and interspecific comparisons highlights the value of studies spanning the spectrum of speciation in related taxa.

  10. Evaluation of Fall Planting Dates of Cumin (Cuminum cyminum L. Ecotypes in Mashhad Conditions

    Directory of Open Access Journals (Sweden)

    Z Khorasani

    2012-07-01

    Full Text Available In order to study the effects of fall planting dates on yield and yield components of six cumin (Cuminum cyminum L. ecotypes an experiment was arranged in a randomized complete block design as a split-plot with three replications during 2007-08 growing season at the Agricultural Research Station of Ferdowsi University of Mashhad. Three planting dates (18 Oct. (first, 8 Nov. (second and 29 Dec. (third and six cumin ecotypes (Torbat heydarieh, Khaf, Sabzevar, Ghaen, Ghoochan and RZ19 were allocated to main and sub plots, respectively. Results showed that the effects of planting dates, ecotypes and interaction effects of planting dates and cumin ecotypes were significant for yield components (winter survival percentage, number of umbel per plant, number of seeds per umbel and 1000-seed weight and seed yield and biological yield. There was a reduction on yield components (number of umbel per plant, number of seeds per umbel and 1000-seed weight, seed yield and biological yield due to delay planting date from 18 Oct. to 29 Dec. The highest winter survival percentage was achieved on the third planting date. The highest and lowest amount for all of the traits, were achieved in Ghaen and RZ19 ecotypes, respectively. According to the useful results and for the deployment of cumin fall planting in other locations of province, continuation of this study to recommended.

  11. Uptake, Distribution and Accumulation of Copper in Two Ecotypes of Elsholtzia

    Institute of Scientific and Technical Information of China (English)

    JIANG Li-Ying; YANG Xiao-E; YE Zheng-Qian; SHI Wei-Yong

    2003-01-01

    Two ecotypes of Elsholtzia, Elsholtzia splendens and E. Argyi, are dominant plants growing on Cu and Pb-Zn smelters, respectively. Samples of the two ecotypes and the corresponding soils from fields of a copper mining area and a Pb-Zn mining area of Zhejiang Province, China, were analyzed to investigate Cu or Zn tolerance of these two ecotypes. Effects of nine Cu levels (0, 5, 10, 20, 40, 80, 160, 240 and 320 mg Cu L-1 as CuSO4@SH20) on growth and uptake, translocation and accumulation of Cu in these two ecotypes were examined in a solution culture experiment. The experimental results showed that dry weights (DW) of shoots and roots were depressed, and growth of E. Splendens was less depressed tha n that of E. Argyi when treated with ≥ 5 mg Cu L-1. Concentrations of Cu in shoots of E. Splendens and E. Argyi exceeded 1 000 mg kg-1 DW at ≥ 40 mg Cu L-x. The maximum Cu accumulated in the shoots of Gu-treated E. Splendens and E. Argyi reached 101 and 142μg plant-1. Furthermore, analysis of plant samples from the fields showed that these two ecotypes can tolerant excess heavy metals and produced high dry matter, and E. Splendens can accumulate 11.7 mg Cu plant-1 grown on the Cu smelter. Therefore, E. Splendens and E. Argyi could be good plants for phytoremediation.

  12. Comparative Genomics of cpn60-Defined Enterococcus hirae Ecotypes and Relationship of Gene Content Differences to Competitive Fitness.

    Science.gov (United States)

    Katyal, Isha; Chaban, Bonnie; Hill, Janet E

    2016-11-01

    Natural microbial communities undergo selection-driven succession with changes in environmental conditions and available nutrients. In a previous study of the pig faecal Enterococcus community, we demonstrated that cpn60 universal target (UT) sequences could resolve phenotypically and genotypically distinct ecotypes of Enterococcus spp. that emerged over time in the faecal microbiome of growing pigs. In this study, we characterized genomic diversity in the identified Enterococcus hirae ecotypes in order to define further the nature and degree of genome content differences between taxa resolved by cpn60 UT sequences. Genome sequences for six representative isolates (two from each of three ecotypes) were compared. Differences in phosphotransferase systems and amino acid metabolism pathways for glutamine, proline and selenocysteine were observed. Differences in the lac family phosphotransferase system corresponded to lactose utilization phenotypes of the isolates. Competitive fitness of the E. hirae ecotypes was evaluated by in vitro growth competition assays in pig faecal extract medium. Isolates from E. hirae-1 and E. hirae-2 ecotypes were able to out-compete isolates from the E. hirae-3 ecotype, consistent with the relatively low abundance of E. hirae-3 relative to E. hirae-1 and E. hirae-2 previously observed in the pig faecal microbiome, and with observed differences between the ecotypes in gene content related to biosynthetic capacity. Results of this study provide a genomic basis for the definition of ecotypes within E. hirae and confirm the utility of the cpn60 UT sequence for high-resolution profiling of complex microbial communities.

  13. Pb uptake, accumulation, subcellular distribution in a Pb-accumulating ecotype of Sedum alfredii (Hance)

    Institute of Scientific and Technical Information of China (English)

    何冰; 杨肖娥; 倪吾钟; 魏幼璋; 叶海波

    2003-01-01

    Lead concentrations in roots, stems and leaves of accumulating and non-accumulating ecotypes of Sedum alfredii (Hance) were studied through a hydroponic experiment with different Pb concentrations sup-plied as Pb( NO3 )2 .Lead concentrations in leaves and stems of the accumulating ecotype were 4-9 times and 3-5 times those of the non-accumulating ecotype, and Pb-accumulated amounts in stems and leaves of theaccumulating ecotype were 4-9 times and 8-1l times higher than those of the non-accumulating ecotype,respectively. The results indicated that the accumulating ecotype had better ability to transport Pb from roots toshoots. The subeellular distributions of Pb in the root, stem and leaf tissues were studied using sucrose differ-ential centrifugation. Approximately 50% of Pb contents was found to be associated with the cell wall fractionin stems of the accumulating ecotype and the percentage increased to 80% both in roots and leaves, no matter when plants were grown with different levels of Pb. The results indicated that the distribution of Pb on cell walls of the accumulating ecotype could mainly account for the high tolerance to Pb.

  14. Agronomic, metabolomic and lipidomic characterisation of Sicilian Origanum vulgare (L.) ecotypes.

    Science.gov (United States)

    Tuttolomondo, Teresa; Martinelli, Federico; Mariotti, Lorenzo; Leto, Claudio; Maggio, Antonella; La Bella, Salvatore

    2016-01-01

    Although Origanum vulgare (L.) has been deeply analysed at phytochemical level, poor knowledge is available regarding non-volatile compounds such as lipids. The aim of this work was to characterise five wild Sicilian Origanum ecotypes from an agronomic, metabolomic and lipidomic perspective. Serradifalco presented higher dry weight and inflorescences/plant than the others while Favara had a significantly higher number of branches per plant and more extensive flowered stratum. Metabolomic analysis, performed with LC-MS-TOF, allowed a preliminary characterisation of the non-volatile metabolome of the five oregano ecotypes Origanum vulgare ssp. hirtum. Twenty-five metabolites were identified belonging to organic acids, amino acids, lysophosphatidylcholines, carnithines, nucleic bases and lysophosphatidylethanolamines. Lipidomic analysis identified 115 polar plant membrane glycerolipid species. Thirteen of them were differentially present in the two chosen ecotypes. The role of these metabolites in plant physiology from a qualitative and pharmacological point of view was discussed.

  15. The molecular dimension of microbial species: 1. Ecological distinctions among, and homogeneity within, putative ecotypes of Synechococcus inhabiting the cyanobacterial mat of Mushroom Spring, Yellowstone National Park

    DEFF Research Database (Denmark)

    Becraft, Eric D.; Wood, Jason M.; Rusch, Douglas B.;

    2015-01-01

    and transcripts over a large number of habitat types in the Mushroom Spring microbial mat. Putative ecological species [putative ecotypes (PEs)], which were predicted by an evolutionary simulation based on the Stable Ecotype Model (Ecotype Simulation), exhibited distinct distributions relative to temperature...

  16. Ultrastructural changes, zinc hyperaccumulation and its relation with antioxidants in two ecotypes of Sedum alfredii Hance.

    Science.gov (United States)

    Jin, Xiao Fen; Yang, Xiao E; Islam, Ejazul; Liu, Dan; Mahmood, Qaisar; Li, Hong; Li, Junying

    2008-11-01

    Zn phytotoxicity and its possible detoxifying responses in two ecotypes of Sedum alfredii Hance, i.e. hyperaccumulating ecotype (HE) and non-hyperaccumulating ecotype (NHE) were investigated. HE grew better with high Zn concentrations of 29.11gkg(-1) DW in shoots when exposed to 500microM Zn2+. Toxicity symptoms caused by Zn in root cells of both ecotypes mainly included plasmolysis, disruption of plasma membranes and increased cell vacuolation. At high supplied Zn concentration, chloroplasts suffered from structural disorganization in both ecotypes. Zn-induced hydrogen peroxide (H2O2) and superoxide radical (O(2)-) productions in leaves were determined by a histochemical method, which revealed that Zn stress may have involved NADPH oxidase, protein phosphatases and intracellular Ca2+ to activate the reactive oxygen species production. Inhibition of glutathione synthesis may have led to increased H2O2 and O(2)- accumulations in leaves of HE. In response to higher Zn concentrations, ascorbic acid significantly increased in both ecotypes and levels of glutathione increased in both leaves and roots of HE and in roots of NHE without any change in the leaves of NHE. The enzymatic activities like those of superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), guaiacol peroxidase (GPX, EC 1.11.1.7), ascorbate peroxidase (APX, EC 1.11.1.11), dehydroascorbate reductase (DHAR, EC 1.8.5.1), and glutathione reductase (GR, EC 1.6.4.2) in leaves of HE were all enhanced at supplied Zn concentration of 500microM, which may account for its better growth.

  17. Phytostabilization potential of two ecotypes of Vetiveria zizanioides in cadmium-contaminated soils: greenhouse and field experiments.

    Science.gov (United States)

    Phusantisampan, Theerawut; Meeinkuirt, Weeradej; Saengwilai, Patompong; Pichtel, John; Chaiyarat, Rattanawat

    2016-10-01

    Soil contamination by cadmium (Cd) poses a serious environmental and public health concern. Phytoremediation, i.e., the use of plants to remove contaminants from soil, has been proposed for treatment of Cd-contaminated ecosystems. In this study, we demonstrated the potential of Vetiveria zizanioides, commonly known as vetiver, to serve as an effective phytoremediation agent. Two ecotypes, i.e., India and Sri Lanka, were grown in greenhouse pots and in the field. Soils were amended with cow manure, pig manure, bat manure, and an organic fertilizer. Among all amendments, pig manure performed best in both greenhouse and field studies in terms of increasing total V. zizanioides biomass production in both ecotypes. In both greenhouse and in the field, tissue of the Sri Lanka ecotype had higher Cd concentrations than did the India ecotype. In the greenhouse, the presence of Cd did not affect total biomass production or root dry weight. The Sri Lanka ecotype had 2.7 times greater adventitious root numbers and 3.6 times greater Cd accumulation in roots than did the India ecotype. In the field study, the Sri Lanka ecotype offers potential as an excluder species, as it accumulated Cd primarily in roots, with translocation factor values 1 for all experiments except for the pig manure amendment. In addition, the highest Cd concentration in the Sri Lanka ecotype root (71.3 mg kg(-1)) was consistent with highest Cd uptake (10.4 mg plant(-1)) in the cow manure treatment. The India ecotype contained lower root Cd concentrations, and Cd accumulation was slightly higher in shoots compared to roots, with translocation factor (TF) values >1. The India ecotype was therefore not considered as an excluder in the Cd-contaminated soil. With the use of excluder species combined with application of organic amendments, soil contamination by Cd may be treated by alternative remediation methods such as phytostabilization.

  18. Cross-cultural and cross-ecotype production of a killer whale `excitement' call suggests universality

    Science.gov (United States)

    Rehn, Nicola; Filatova, Olga A.; Durban, John W.; Foote, Andrew D.

    2011-01-01

    Facial and vocal expressions of emotion have been found in a number of social mammal species and are thought to have evolved to aid social communication. There has been much debate about whether such signals are culturally inherited or are truly biologically innate. Evidence for the innateness of such signals can come from cross-cultural studies. Previous studies have identified a vocalisation (the V4 or `excitement' call) associated with high arousal behaviours in a population of killer whales in British Columbia, Canada. In this study, we compared recordings from three different socially and reproductively isolated ecotypes of killer whales, including five vocal clans of one ecotype, each clan having discrete culturally transmitted vocal traditions. The V4 call was found in recordings of each ecotype and each vocal clan. Nine independent observers reproduced our classification of the V4 call from each population with high inter-observer agreement. Our results suggest the V4 call may be universal in Pacific killer whale populations and that transmission of this call is independent of cultural tradition or ecotype. We argue that such universality is more consistent with an innate vocalisation than one acquired through social learning and may be linked to its apparent function of motivational expression.

  19. Ecotypic differentiation in thermal traits in the tropical to warm-temperate green macrophyte Valonia utricularis

    NARCIS (Netherlands)

    Eggert, A.; Burger, E.M.; Breeman, Arno

    2003-01-01

    Differentiation of thermal traits (i.e. growth, survival and reproduction) was studied in the green macrophyte Valonia utricularis (Roth) C. Agardh, which has a world-wide tropical to warm-temperate distribution. Ecotypic differentiation between northeast Atlantic/Mediterranean and Indo-west Pacific

  20. Population genomics of the killer whale indicates ecotype evolution in sympatry involving both selection and drift.

    Science.gov (United States)

    Moura, Andre E; Kenny, John G; Chaudhuri, Roy; Hughes, Margaret A; J Welch, Andreanna; Reisinger, Ryan R; de Bruyn, P J Nico; Dahlheim, Marilyn E; Hall, Neil; Hoelzel, A Rus

    2014-11-01

    The evolution of diversity in the marine ecosystem is poorly understood, given the relatively high potential for connectivity, especially for highly mobile species such as whales and dolphins. The killer whale (Orcinus orca) has a worldwide distribution, and individual social groups travel over a wide geographic range. Even so, regional populations have been shown to be genetically differentiated, including among different foraging specialists (ecotypes) in sympatry. Given the strong matrifocal social structure of this species together with strong resource specializations, understanding the process of differentiation will require an understanding of the relative importance of both genetic drift and local adaptation. Here we provide a high-resolution analysis based on nuclear single-nucleotide polymorphic markers and inference about differentiation at both neutral loci and those potentially under selection. We find that all population comparisons, within or among foraging ecotypes, show significant differentiation, including populations in parapatry and sympatry. Loci putatively under selection show a different pattern of structure compared to neutral loci and are associated with gene ontology terms reflecting physiologically relevant functions (e.g. related to digestion). The pattern of differentiation for one ecotype in the North Pacific suggests local adaptation and shows some fixed differences among sympatric ecotypes. We suggest that differential habitat use and resource specializations have promoted sufficient isolation to allow differential evolution at neutral and functional loci, but that the process is recent and dependent on both selection and drift.

  1. Hybrid Sterility over Tens of Meters Between Ecotypes Adapted to Serpentine and Non-Serpentine Soils

    Science.gov (United States)

    Leonie Moyle; Levine Mia; Stanton Maureen; Jessica Wright

    2012-01-01

    The development of hybrid sterility is an important step in the process of speciation, however the role of adaptive evolution in triggering these postzygotic barriers is poorly understood. We show that, in the California endemic plant Collinsia sparsiflora ecotypic adaptation to two distinct soil types is associated with the expression of...

  2. Mixing of porpoise ecotypes in southwestern UK waters revealed by genetic profiling.

    Science.gov (United States)

    Fontaine, Michaël C; Thatcher, Oliver; Ray, Nicolas; Piry, Sylvain; Brownlow, Andrew; Davison, Nicholas J; Jepson, Paul; Deaville, Rob; Goodman, Simon J

    2017-03-01

    Contact zones between ecotypes are windows for understanding how species may react to climate changes. Here, we analysed the fine-scale genetic and morphological variation in harbour porpoises (Phocoena phocoena) around the UK by genotyping 591 stranded animals at nine microsatellite loci. The data were integrated with a prior study to map at high resolution the contact zone between two previously identified ecotypes meeting in the northern Bay of Biscay. Clustering and spatial analyses revealed that UK porpoises are derived from two genetic pools with porpoises from the southwestern UK being genetically differentiated, and having larger body sizes compared to those of other UK areas. Southwestern UK porpoises showed admixed ancestry between southern and northern ecotypes with a contact zone extending from the northern Bay of Biscay to the Celtic Sea and Channel. Around the UK, ancestry blends from one genetic group to the other along a southwest--northeast axis, correlating with body size variation, consistent with previously reported morphological differences between the two ecotypes. We also detected isolation by distance among juveniles but not in adults, suggesting that stranded juveniles display reduced intergenerational dispersal. The fine-scale structure of this admixture zone raises the question of how it will respond to future climate change and provides a reference point for further study.

  3. Ecotypes as a concept for exploring responses to climate change in fish assemblage

    NARCIS (Netherlands)

    Engelhard, G.H.; Ellis, J.R.; Payne, M.R.; Hofstede, ter R.; Pinnegar, J.K.

    2011-01-01

    How do species-rich fish assemblages respond to climate change or to other anthropogenic or environmental drivers? To explore this, a categorization concept is presented whereby species are assigned with respect to six ecotype classifications, according to biogeography, horizontal and vertical habit

  4. Photosynthetic pigments and stomatal conductance in ecotypes of copoazu (Theobroma grandi orum Willd. Ex. Spreng K. Schum..

    Directory of Open Access Journals (Sweden)

    Juan Carlos Suárez-Salazar

    2016-12-01

    Full Text Available The objective of this work was to evaluate the variability of photosynthetic pigment content and daily stomatal conductance was evaluated in relation to environmental variables in Copoazú (Theobroma grandi orum ecotypes. The ecotypes used were part of the germoplasm bank of the University of the Amazon (Colombia. The study was carried out during the year 2015. Four leaves of the average stratum of four plants were collected for each ecotype, to extract and read at different levels of absorbance and determine the content of photosynthetic pigments. During the hours of 04:00 a.m. to 6:00 p.m., the stomatal conductance (gs was monitored for environmental variables (relative humidity, air temperature, radiation and vapor pressure de cit (VPD. An analysis of variance was made using the Tukey test, correlations and regressions were made between gs and environmental variables. The contents of chlorophyll a, b, total and carotenoids among ecotypes were different (P<0.0001, the ecotype UA-31 presented the highest values, contrasting with the ecotype UA-37. Concerning gs, the interaction ecotype*hour showed signi cant differences (P<0.0001 .The ecotypes that presented the highest values of gs were UA-67 and UA-039, (P<0.0001, radiation (-0.91, P<0.0001 and DPV (-0.94; P<0.0001 0.0001.The results suggest that ecotypes UA-039 and UA-31 were the most suitable in terms of gaseous exchange and content of photosynthetic pigments.

  5. Phenotypic plasticity of sun and shade ecotypes of Stellaria longipes in response to light quality signaling, gibberellins and auxin.

    Science.gov (United States)

    Kurepin, Leonid V; Pharis, Richard P; Neil Emery, R J; Reid, David M; Chinnappa, C C

    2015-09-01

    Stellaria longipes plant communities (ecotypes) occur in several environmentally distinct habitats along the eastern slopes of southern Alberta's Rocky Mountains. One ecotype occurs in a prairie habitat at ∼1000 m elevation where Stellaria plants grow in an environment in which the light is filtered by taller neighbouring vegetation, i.e. sunlight with a low red to far-red (R/FR) ratio. This ecotype exhibits a high degree of phenotypic plasticity by increasing stem elongation in response to the low R/FR ratio light signal. Another Stellaria ecotype occurs nearby at ∼2400 m elevation in a much cooler alpine habitat, one where plants rarely experience low R/FR ratio shade light. Stem elongation of plants is largely regulated by gibberellins (GAs) and auxin, indole-3-acetic acid (IAA). Shoots of the prairie ecotype plants show increased IAA levels under low R/FR ratio light and they also increase their stem growth in response to applied IAA. The alpine ecotype plants show neither response. Plants from both ecotypes produce high levels of growth-active GA1 under low R/FR ratio light, though they differ appreciably in their catabolism of GA1. The alpine ecotype plants exhibit very high levels of GA8, the inactive product of GA1 metabolism, under both normal and low R/FR ratio light. Alpine origin plants may de-activate GA1 by conversion to GA8 via a constitutively high level of expression of the GA2ox gene, thereby maintaining their dwarf phenotype and exhibiting a reduced phenotypic plasticity in terms of shoot elongation. In contrast, prairie plants exhibit a high degree of phenotypic plasticity, using low R/FR ratio light-mediated changes in GA and IAA concentrations to increase shoot elongation, thereby accessing direct sunlight to optimize photosynthesis. There thus appear to be complex adaptation strategies for the two ecotypes, ones which involve modifications in the homeostasis of endogenous hormones.

  6. Adaptive responses reveal contemporary and future ecotypes in a desert shrub.

    Science.gov (United States)

    Richardson, Bryce A; Kitchen, Stanley G; Pendleton, Rosemary L; Pendleton, Burton K; Germino, Matthew J; Rehfeldt, Gerald E; Meyer, Susan E

    2014-03-01

    Interacting threats to ecosystem function, including climate change, wildfire, and invasive species necessitate native plant restoration in desert ecosystems. However, native plant restoration efforts often remain unguided by ecological genetic information. Given that many ecosystems are in flux from climate change, restoration plans need to account for both contemporary and future climates when choosing seed sources. In this study we analyze vegetative responses, including mortality, growth, and carbon isotope ratios in two blackbrush (Coleogyne ramosissima) common gardens that included 26 populations from a range-wide collection. This shrub occupies ecotones between the warm and cold deserts of Mojave and Colorado Plateau ecoregions in western North America. The variation observed in the vegetative responses of blackbrush populations was principally explained by grouping populations by ecoregions and by regression with site-specific climate variables. Aridity weighted by winter minimum temperatures best explained vegetative responses; Colorado Plateau sites were usually colder and drier than Mojave sites. The relationship between climate and vegetative response was mapped within the boundaries of the species-climate space projected for the contemporary climate and for the decade surrounding 2060. The mapped ecological genetic pattern showed that genetic variation could be classified into cool-adapted and warm-adapted ecotypes, with populations often separated by steep dines. These transitions are predicted to occur in both the Mojave Desert and Colorado Plateau ecoregions. While under contemporary conditions the warm-adapted ecotype occupies the majority of climate space, climate projections predict that the cool-adapted ecotype could prevail as the dominant ecotype as the climate space of blackbrush expands into higher elevations and latitudes. This study provides the framework for delineating climate change-responsive seed transfer guidelines, which are needed

  7. Evaluation of Freeze Tolerance in Lancelot Plantain (Plantago lanceolata L. Ecotypes under Controlled Conditions

    Directory of Open Access Journals (Sweden)

    M. Janalizadeh

    2016-02-01

    Full Text Available Introduction Lancelot Plantain (Ribwort, narrow-leaf or English plantain is a deep-rooted, short-lived perennial herb from Plantaginaceae family which has been used for various medicinal purposes for centuries, especially in Europe and only more recently has been proposed as a forage plant. The leaf of plantain is highly palatable for grazing animals, providing mineral-rich forage. Recently two productive upright cultivars of plantain have been bred and introduced, Grasslands Lancelot and the more erect winter active Ceres Tonic. Plantain grows moderately in winter but its main growth periods beings in spring and autumn with opportunistic summer growth. Although it reveals suitable winter survival in natural conditions, but there is not a lot of information about cold tolerance of this plant. So it is important to recognize the freeze tolerance of narrow leaf plantain for successful planting and utilization in cold regions such as Mashhad in Khorasan Razavi Province (Northeast of Iran. Determining LT50 point or critical temperature for survival of plant is the most reliable and simple method for evaluating cold tolerance of plants. Another reliable method for freeze tolerance of plants is estimation of temperature at which 50 % of dry matter reduces (RDMT50. This experiment was carried out to evaluate freeze tolerance of five ecotypes of Lancelot plantain according to the LT50su and RDMT50 indices. Materials and Methods In order to evaluate freeze tolerance of Lancelot plantain, a factorial experiment based on completely randomized design with three replications was carried out under controlled conditions at college of agriculture, Ferdowsi University of Mashhad. Five ecotypes of Lancelot plantain (Bojnourd, Kalat, Mashhad, Ghayen and Birjand after three months growth and hardening in natural environment were transferred to a Thermo gradient freezer on January 20th, 2012 and exposed to eight freezing temperatures (Zero, -3, -6, -9, -12, -15, -18

  8. Application of otolith shape analysis in identifying different ecotypes of Coilia ectenes in the Yangtze Basin, China

    Digital Repository Service at National Institute of Oceanography (India)

    Radhakrishnan, K.V.; Li, Y.; Jayalakshmy, K.V.; Liu, M.; Murphy, B.R.; Xie, S.

    As the three ecotypes of C. ectenes are prone to intermixing along Yangtze, 84 identifying an efficient methodology for their distinction is imperative. In several cases of 85 recent morphological and genetic studies, controversy arose... 3.2. Shape visualization 190 191 The average shape of the otoliths showed distinct differences among the three 192 ecotypes (Fig. 4). There was a well-developed antirostrum for both the anadromous and 193 the land...

  9. Clustering of Subgingival Microbiota Reveals Microbial Disease Ecotypes Associated with Clinical Stages of Periodontitis in a Cross-Sectional Study

    Science.gov (United States)

    Boutin, Sébastien; Hagenfeld, Daniel; Zimmermann, Heiko; El Sayed, Nihad; Höpker, Tanja; Greiser, Halina K.; Becher, Heiko; Kim, Ti-Sun; Dalpke, Alexander H.

    2017-01-01

    Periodontitis is characterized by chronic inflammation associated with alteration of the oral microbiota. In contrast to previous microbiome studies focusing a priori on comparison between extreme phenotypes, our study analyzed a random sample of 85 people. The aim of this study was to link microbial differences to disease’s prevalence and severity. Using next generation sequencing of 16S rRNA amplicons and cluster analysis, we observed that the population can be divided into two major ecotypes: One mainly contained periodontal healthy/mild periodontitis individuals whereas the second ecotype showed a heterogeneous microbial distribution and clustered into three distinct sub-ecotypes. Those sub-ecotypes differed with respect to the frequency of diseased patients and displayed a gradual change in distinct subgingival microbiota that goes along with clinical disease symptoms. In ecotype 2, the subgroup with no clinical signs of disease was linked to an increase of F. nucleatum vincentii but also several other species, while only in “end-stage” dysbiosis classical red complex bacteria gained overweight. Therefore, the microbial disease ecotypes observed in our population can lead to an establishment of an early microbial risk profile for clinically healthy patients. PMID:28298910

  10. Genome-scale cold stress response regulatory networks in ten Arabidopsis thaliana ecotypes

    DEFF Research Database (Denmark)

    Barah, Pankaj; Jayavelu, Naresh Doni; Rasmussen, Simon

    2013-01-01

    BACKGROUND: Low temperature leads to major crop losses every year. Although several studies have been conducted focusing on diversity of cold tolerance level in multiple phenotypically divergent Arabidopsis thaliana (A. thaliana) ecotypes, genome-scale molecular understanding is still lacking...... using Arabidopsis NimbleGen ATH6 microarrays. In total 6061 transcripts were significantly cold regulated (p majority of the transcripts (75%) showed ecotype specific expression pattern. By using sequence data...... available from Arabidopsis thaliana 1001 genome project, we further investigated sequence polymorphisms in the core cold stress regulon genes. Significant numbers of non-synonymous amino acid changes were observed in the coding region of the CBF regulon genes. Considering the limited knowledge about...

  11. Characterization of starch from two ecotypes of andean achira roots (Canna edulis).

    Science.gov (United States)

    Cisneros, Fausto H; Zevillanos, Roberto; Cisneros-Zevallos, Luis

    2009-08-26

    Starches from two ecotypes of achira roots (Canna edulis Ker-Gawler) were characterized and compared to commercial potato and corn starches. This included scanning electron microscopy (SEM) of starch granules and amylose content determination of starch. Starch solutions or gels were tested by rotational viscometry, Rapid Visco Analyzer (RVA), and texture analysis. Some starch samples were subjected to various treatments: pH reduction, autoclaving at high temperature, and high shear before testing by rotational viscometry. Achira starch showed some unusual properties, such as very large oblong granules (approximately 45-52 microm major axis and approximately 33-34 microm minor axis) and relatively high amylose content (approximately 33-39%). The San Gaban achira ecotype formed high-consistency gels upon cooling, both in RVA study (5% starch) and in texture analysis (8% starch), compared to other starch gels and also exhibited higher thermal resistance to viscosity breakdown.

  12. Ecotypes as a concept for exploring responses to climate change in fish assemblages

    DEFF Research Database (Denmark)

    Engelhard, George H.; Ellis, Jim R.; Payne, Mark;

    2011-01-01

    How do species-rich fish assemblages respond to climate change or to other anthropogenic or environmental drivers? To explore this, a categorization concept is presented whereby species are assigned with respect to six ecotype classifications, according to biogeography, horizontal and vertical...... habitat preference, trophic guild, trophic level, or body size. These classification schemes are termed ecotypology, and the system is applied to fish in the North Sea using International Bottom Trawl Survey data. Over the period 1977–2008, there were changes in the North Sea fish community that can...... or combinations of them. The post-1989 warm biological regime appears to have favoured pelagic species more than demersal species. These community-level patterns agree with the expected responses of ecotypes to climate change and also with anticipated vulnerability to fishing pressure....

  13. Genome-scale cold stress response regulatory networks in ten Arabidopsis thaliana ecotypes

    DEFF Research Database (Denmark)

    Barah, Pankaj; Jayavelu, Naresh Doni; Rasmussen, Simon;

    2013-01-01

    ontology (GO) categories were identified to delineate natural variation of cold stress regulated differential gene expression in the model plant A. thaliana. The predicted regulatory network model was able to identify new ecotype specific transcription factors and their regulatory interactions, which might...... using Arabidopsis NimbleGen ATH6 microarrays. In total 6061 transcripts were significantly cold regulated (p expression pattern. By using sequence data...

  14. Genetic and ecotypic differentiation in a Californian plant polyploid complex (Grindelia, Asteraceae.

    Directory of Open Access Journals (Sweden)

    Abigail J Moore

    Full Text Available Studies of ecotypic differentiation in the California Floristic Province have contributed greatly to plant evolutionary biology since the pioneering work of Clausen, Keck, and Hiesey. The extent of gene flow and genetic differentiation across interfertile ecotypes that span major habitats in the California Floristic Province is understudied, however, and is important for understanding the prospects for local adaptation to evolve or persist in the face of potential gene flow across populations in different ecological settings. We used microsatellite data to examine local differentiation in one of these lineages, the Pacific Coast polyploid complex of the plant genus Grindelia (Asteraceae. We examined 439 individuals in 10 different populations. The plants grouped broadly into a coastal and an inland set of populations. The coastal group contained plants from salt marshes and coastal bluffs, as well as a population growing in a serpentine grassland close to the coast, while the inland group contained grassland plants. No evidence for hybridization was found at the single location where adjacent populations of the two groups were sampled. In addition to differentiation along ecotypic lines, there was also a strong signal of local differentiation, with the plants grouping strongly by population. The strength of local differentiation is consistent with the extensive morphological variation observed across populations and the history of taxonomic confusion in the group. The Pacific Clade of Grindelia and other young Californian plant groups warrant additional analysis of evolutionary divergence along the steep coast-to-inland climatic gradient, which has been associated with local adaptation and ecotype formation since the classic studies of Clausen, Keck, and Hiesey.

  15. Genetic and ecotypic differentiation in a Californian plant polyploid complex (Grindelia, Asteraceae).

    Science.gov (United States)

    Moore, Abigail J; Moore, William L; Baldwin, Bruce G

    2014-01-01

    Studies of ecotypic differentiation in the California Floristic Province have contributed greatly to plant evolutionary biology since the pioneering work of Clausen, Keck, and Hiesey. The extent of gene flow and genetic differentiation across interfertile ecotypes that span major habitats in the California Floristic Province is understudied, however, and is important for understanding the prospects for local adaptation to evolve or persist in the face of potential gene flow across populations in different ecological settings. We used microsatellite data to examine local differentiation in one of these lineages, the Pacific Coast polyploid complex of the plant genus Grindelia (Asteraceae). We examined 439 individuals in 10 different populations. The plants grouped broadly into a coastal and an inland set of populations. The coastal group contained plants from salt marshes and coastal bluffs, as well as a population growing in a serpentine grassland close to the coast, while the inland group contained grassland plants. No evidence for hybridization was found at the single location where adjacent populations of the two groups were sampled. In addition to differentiation along ecotypic lines, there was also a strong signal of local differentiation, with the plants grouping strongly by population. The strength of local differentiation is consistent with the extensive morphological variation observed across populations and the history of taxonomic confusion in the group. The Pacific Clade of Grindelia and other young Californian plant groups warrant additional analysis of evolutionary divergence along the steep coast-to-inland climatic gradient, which has been associated with local adaptation and ecotype formation since the classic studies of Clausen, Keck, and Hiesey.

  16. Ecotype dependent expression and alternative splicing of epithiospecifier protein (ESP) in Arabidopsis thaliana.

    Science.gov (United States)

    Kissen, R; Hyldbakk, E; Wang, C-W V; Sørmo, C G; Rossiter, J T; Bones, A M

    2012-03-01

    Epithiospecifier protein (ESP) is responsible for diverting glucosinolate hydrolysis from the generation of isothiocyanates to that of epithionitriles or nitriles, and thereby negatively affects the ability of the plant to defend itself against certain insects. Despite this important role of ESP, little is known about its expression in plant tissues and the regulation thereof. We therefore investigated ESP expression by qPCR and Western blot in different organs during the growth cycle of the two Arabidopsis thaliana ecotypes Col-0 and Mt-0. Besides the fact that ESP transcript and protein levels were revealed to be much higher in Mt-0 than in Col-0 in all cases, our qPCR results also indicated that ESP expression is regulated differently in the two A. thaliana ecotypes. No ESP protein was detected by Western blot in any organ or developmental stage for Col-0. During the assays an alternative splice variant of ESP was identified in Col-0, but not Mt-0, leading to a mis-spliced transcript which could explain the low expression levels of ESP in the former ecotype. Analysis of genomic sequences containing the ESP splice sites, of ESP protein level and ESP activity from seven A. thaliana ecotypes showed a positive correlation between the presence of a non-canonical 5' splice site for ESP and the absence of detectable ESP protein levels and ESP activity. When analysing the expression of both transcript variants in Col-0 after treatment with methyl jasmonate, a condition known to "induce ESP", it was indeed the alternative splice variant that was preferentially induced.

  17. Plant response to climate change varies with topography, interactions with neighbors, and ecotype.

    Science.gov (United States)

    Liancourt, Pierre; Spence, Laura A; Song, Daniel S; Lkhagva, Ariuntsetseg; Sharkhuu, Anarmaa; Boldgiv, Bazartseren; Helliker, Brent R; Petraitis, Peter S; Casper, Brenda B

    2013-02-01

    Predicting the future of any given species represents an unprecedented challenge in light of the many environmental and biological factors that affect organismal performance and that also interact with drivers of global change. In a three-year experiment set in the Mongolian steppe, we examined the response of the common grass Festuca lenensis to manipulated temperature and water while controlling for topographic variation, plant-plant interactions, and ecotypic differentiation. Plant survival and growth responses to a warmer, drier climate varied within the landscape. Response to simulated increased precipitation occurred only in the absence of neighbors, demonstrating that plant-plant interactions can supersede the effects of climate change. F. lenensis also showed evidence of local adaptation in populations that were only 300 m apart. Individuals from the steep and dry upper slope showed a higher stress/drought tolerance, whereas those from the more productive lower slope showed a higher biomass production and a greater ability to cope with competition. Moreover, the response of this species to increased precipitation was ecotype specific, with water addition benefiting only the least stress-tolerant ecotype from the lower slope origin. This multifaceted approach illustrates the importance of placing climate change experiments within a realistic ecological and evolutionary framework. Existing sources of variation impacting plant performance may buffer or obscure climate change effects.

  18. Different utilization of alginate and other algal polysaccharides by marine Alteromonas macleodii ecotypes.

    Science.gov (United States)

    Neumann, Anna M; Balmonte, John P; Berger, Martine; Giebel, Helge-Ansgar; Arnosti, Carol; Voget, Sonja; Simon, Meinhard; Brinkhoff, Thorsten; Wietz, Matthias

    2015-10-01

    The marine bacterium Alteromonas macleodii is a copiotrophic r-strategist, but little is known about its potential to degrade polysaccharides. Here, we studied the degradation of alginate and other algal polysaccharides by A. macleodii strain 83-1 in comparison to other A. macleodii strains. Cell densities of strain 83-1 with alginate as sole carbon source were comparable to those with glucose, but the exponential phase was delayed. The genome of 83-1 was found to harbour an alginolytic system comprising five alginate lyases, whose expression was induced by alginate. The alginolytic system contains additional CAZymes, including two TonB-dependent receptors, and is part of a 24 kb genomic island unique to the A. macleodii 'surface clade' ecotype. In contrast, strains of the 'deep clade' ecotype contain only a single alginate lyase in a separate 7 kb island. This difference was reflected in an eightfold greater efficiency of surface clade strains to grow on alginate. Strain 83-1 furthermore hydrolysed laminarin, pullulan and xylan, and corresponding polysaccharide utilization loci were detected in the genome. Alteromonas macleodii alginate lyases were predominantly detected in Atlantic Ocean metagenomes. The demonstrated hydrolytic capacities are likely of ecological relevance and represent another level of adaptation among A. macleodii ecotypes.

  19. Scaling-up permafrost thermal measurements in western Alaska using an ecotype approach

    Science.gov (United States)

    Cable, William L.; Romanovsky, Vladimir E.; Torre Jorgenson, M.

    2016-10-01

    Permafrost temperatures are increasing in Alaska due to climate change and in some cases permafrost is thawing and degrading. In areas where degradation has already occurred the effects can be dramatic, resulting in changing ecosystems, carbon release, and damage to infrastructure. However, in many areas we lack baseline data, such as subsurface temperatures, needed to assess future changes and potential risk areas. Besides climate, the physical properties of the vegetation cover and subsurface material have a major influence on the thermal state of permafrost. These properties are often directly related to the type of ecosystem overlaying permafrost. In this paper we demonstrate that classifying the landscape into general ecotypes is an effective way to scale up permafrost thermal data collected from field monitoring sites. Additionally, we find that within some ecotypes the absence of a moss layer is indicative of the absence of near-surface permafrost. As a proof of concept, we used the ground temperature data collected from the field sites to recode an ecotype land cover map into a map of mean annual ground temperature ranges at 1 m depth based on analysis and clustering of observed thermal regimes. The map should be useful for decision making with respect to land use and understanding how the landscape might change under future climate scenarios.

  20. Diversity of Ralstonia solanacearum in French Guiana expands knowledge of the "emerging ecotype".

    Science.gov (United States)

    Deberdt, P; Guyot, J; Coranson-Beaudu, R; Launay, J; Noreskal, M; Rivière, P; Vigné, F; Laplace, D; Lebreton, L; Wicker, E

    2014-06-01

    Although bacterial wilt remains a major plant disease throughout South America and the Caribbean, the diversity of prevalent Ralstonia solanacearum populations is largely unknown. The genetic and phenotypic diversity of R. solanacearum strains in French Guiana was assessed using diagnostic polymerase chain reactions and sequence-based (egl and mutS) genotyping on a 239-strain collection sampled on the families Solanaceae and Cucurbitaceae, revealing an unexpectedly high diversity. Strains were distributed within phylotypes I (46.9%), IIA (26.8%), and IIB (26.3%), with one new endoglucanase sequence type (egl ST) found within each group. Phylotype IIB strains consisted mostly (97%) of strains with the emerging ecotype (IIB/sequevar 4NPB). Host range of IIB/4NPB strains from French Guiana matched the original emerging reference strain from Martinique. They were virulent on cucumber; virulent and highly aggressive on tomato, including the resistant reference Hawaii 7996; and only controlled by eggplant SM6 and Surya accessions. The emerging ecotype IIB/4NPB is fully established in French Guiana in both cultivated fields and uncultivated forest, rendering the hypothesis of introduction via ornamental or banana cuttings unlikely. Thus, this ecotype may have originated from the Amazonian region and spread throughout the Caribbean region.

  1. Effect of Seawater Stress on Physiological and Biochemical Responses of Five Jerusalem Artichoke Ecotypes

    Institute of Scientific and Technical Information of China (English)

    LONG Xiao-Hua; CHI Jin-He; LIU Ling; LI Qing; LIU Zhao-Pu

    2009-01-01

    Three treatments consisting of 0%,15%,and 30% seawater were investigated to analyse the ecotypic variabilities among five populations of Jerusalem artichoke (Helianthus tuberosus) regarding their responses to seawater stress under a hydroponic culture system.Analyses were done 2,4,and 6 days after treatments.The 15% and 30% seawater treatments reduced the growth rates of roots and shoots of H.tuberosus populations.The activities of superoxide dismutase,peroxidase,and catalase majored in the leaves were stimulated under the seawater stress.The electrolyte leakage and malondialdehyde contents of the leaves were also stimulated owing to seawater stress.The contents of proline and solublesugars in the leaves increased significantly with increasing seawater concentrations.The concentrations of Na+,K+,and Cl-in the aerial parts and roots increased with an increase in the seawater concentration throughout the experimental period.There were ccotypic differences among the five populations of H.tuberosus as evidenced by the analyses of the above items in both aerial parts and roots under seawater treatment.The magnitude of the ecotypic variance components indicated that a substantial proportion of the total variation for these physiological and biochemical responses were owing to ecotype,indicating the possibility of improvement through hybridization and selection.

  2. The molecular dimension of microbial species: 1. Ecological distinctions among, and homogeneity within, putative ecotypes of Synechococcus inhabiting the cyanobacterial mat of Mushroom Spring, Yellowstone National Park

    Directory of Open Access Journals (Sweden)

    Eric Daniel Becraft

    2015-06-01

    Full Text Available Based on the Stable Ecotype Model, evolution leads to the divergence of ecologically distinct populations (e.g., with different niches and/or behaviors of ecologically interchangeable membership. In this study, pyrosequencing was used to provide deep sequence coverage of Synechococcus psaA genes and transcripts over a large number of habitat types in the Mushroom Spring microbial mat. Putative ecological species (putative ecotypes, which were predicted by an evolutionary simulation based on the Stable Ecotype Model (Ecotype Simulation, exhibited distinct distributions relative to temperature-defined positions in the effluent channel and vertical position in the upper 1 mm-thick mat layer. Importantly, in most cases variants predicted to belong to the same putative ecotype formed unique clusters relative to temperature and depth in the mat in canonical correspondence analysis, supporting the hypothesis that while the putative ecotypes are ecologically distinct, the members of each ecotype are ecologically homogeneous. Putative ecotypes responded differently to experimental perturbations of temperature and light, but the genetic variation within each putative ecotype was maintained as the relative abundances of putative ecotypes changed, further indicating that each population responded as a set of ecologically interchangeable individuals. Compared to putative ecotypes that predominate deeper within the mat photic zone, the timing of transcript abundances for selected genes differed for putative ecotypes that predominate in microenvironments closer to upper surface of the mat with spatiotemporal differences in light and O2 concentration. All of these findings are consistent with the hypotheses that Synechococcus species in hot spring mats are sets of ecologically interchangeable individuals that are differently adapted, that these adaptations control their distributions, and that the resulting distributions constrain the activities of the species

  3. Evaluating Ecotypes as a means of Scaling-up Permafrost Thermal Measurements in Western Alaska.

    Science.gov (United States)

    Cable, William; Romanovsky, Vladimir

    2015-04-01

    In many regions, permafrost temperatures are increasing due to climate change and in some cases permafrost is thawing and degrading. In areas where degradation has already occurred the effects can be dramatic, resulting in changing ecosystems, carbon release, and damage to infrastructure. Yet in many areas we lack baseline data, such as subsurface temperatures, needed to assess future changes and potential risk areas. Besides climate, the physical properties of the vegetation cover and subsurface material have a major influence on the thermal state of permafrost. These properties are often directly related to the type of ecosystem overlaying permafrost. Thus, classifying the landscape into general ecotypes might be an effective way to scale up permafrost thermal data. To evaluate using ecotypes as a way of scaling-up permafrost thermal data within a region we selected an area in Western Alaska, the Selawik National Wildlife Refuge, which is on the boundary between continuous and discontinuous permafrost. This region was selected because previously an ecological land classification had been conducted and a very high-resolution ecotype map was generated. Using this information we selected 18 spatially distributed sites covering the most abundant ecotypes, where we are collecting low vertical resolution soil temperature data to a depth of 1.5 meters at most sites. At three additional core sites, we are collecting air temperature, snow depth, and high vertical resolution soil temperature to a depth of 3 meters. The sites were installed in the summers of 2011 and 2012; consequently, we have at least two years of data from all sites. Mean monthly and mean annual air temperature and snow depth for all three core sites are similar within the 2012-2014 period. Additionally, the average air temperature and snow depth from our three cores sites compares well with that of a nearby meteorological station for which long-term data is available. During the study period snow depth

  4. Moderate Drought Stress Induces Increased Foliar Dimethylsulphoniopropionate (DMSP Concentration and Isoprene Emission in Two Contrasting Ecotypes of Arundo donax

    Directory of Open Access Journals (Sweden)

    Matthew Haworth

    2017-06-01

    Full Text Available The function of dimethylsulphoniopropionate (DMSP in plants is unclear. It has been proposed as an antioxidant, osmolyte and overflow for excess energy under stress conditions. The formation of DMSP is part of the methionine (MET pathway that is involved in plant stress responses. We used a new analytical approach to accurately quantify the changes in DMSP concentration that occurred in two ecotypes of the biomass crop Arundo donax subject to moderate drought stress under field conditions. The ecotypes of A. donax were from a hot semi-arid habitat in Morocco and a warm-humid environment in Central Italy. The Moroccan ecotype showed more pronounced reductions in photosynthesis, stomatal conductance and photochemical electron transport than the Italian ecotype. An increase in isoprene emission occurred in both ecotypes alongside enhanced foliar concentrations of DMSP, indicative of a protective function of these two metabolites in the amelioration of the deleterious effects of excess energy and oxidative stress. This is consistent with the modification of carbon within the methyl-erythritol and MET pathways responsible for increased synthesis of isoprene and DMSP under moderate drought. The results of this study indicate that DMSP is an important adaptive component of the stress response regulated via the MET pathway in A. donax. DMSP is likely a multifunctional molecule playing a number of roles in the response of A. donax to reduced water availability.

  5. Parallel genetic divergence among coastal-marine ecotype pairs of European anchovy explained by differential introgression after secondary contact.

    Science.gov (United States)

    Le Moan, A; Gagnaire, P-A; Bonhomme, F

    2016-07-01

    Ecophenotypic differentiation among replicate ecotype pairs within a species complex is often attributed to independent outcomes of parallel divergence driven by adaptation to similar environmental contrasts. However, the extent to which parallel phenotypic and genetic divergence patterns have emerged independently is increasingly questioned by population genomic studies. Here, we document the extent of genetic differentiation within and among two geographic replicates of the coastal and marine ecotypes of the European anchovy (Engraulis encrasicolus) gathered from Atlantic and Mediterranean locations. Using a genome-wide data set of RAD-derived SNPs, we show that habitat type (marine vs. coastal) is the most important component of genetic differentiation among populations of anchovy. By analysing the joint allele frequency spectrum of each coastal-marine ecotype pair, we show that genomic divergence patterns between ecotypes can be explained by a postglacial secondary contact following a long period of allopatric isolation (c. 300 kyrs). We found strong support for a model including heterogeneous migration among loci, suggesting that secondary gene flow has eroded past differentiation at different rates across the genome. Markers experiencing reduced introgression exhibited strongly correlated differentiation levels among Atlantic and Mediterranean regions. These results support that partial reproductive isolation and parallel genetic differentiation among replicate pairs of anchovy ecotypes are largely due to a common divergence history prior to secondary contact. They moreover provide comprehensive insights into the origin of a surprisingly strong fine-scale genetic structuring in a high gene flow marine fish, which should improve stock management and conservation actions.

  6. Ecotype variability in growth and secondary metabolite profile in Moringa oleifera: impact of sulfur and water availability.

    Science.gov (United States)

    Förster, Nadja; Ulrichs, Christian; Schreiner, Monika; Arndt, Nick; Schmidt, Reinhard; Mewis, Inga

    2015-03-25

    Moringa oleifera is widely cultivated in plantations in the tropics and subtropics. Previous cultivation studies with M. oleifera focused primarily only on leaf yield. In the present study, the content of potentially health-promoting secondary metabolites (glucosinolates, phenolic acids, and flavonoids) were also investigated. Six different ecotypes were grown under similar environmental conditions to identify phenotypic differences that can be traced back to the genotype. The ecotypes TOT4880 (origin USA) and TOT7267 (origin India) were identified as having the best growth performance and highest secondary metabolite production, making them an ideal health-promoting food crop. Furthermore, optimal cultivation conditions-exemplarily on sulfur fertilization and water availability-for achieving high leaf and secondary metabolite yields were investigated for M. oleifera. In general, plant biomass and height decreased under water deficiency compared to normal cultivation conditions, whereas the glucosinolate content increased. The effects depended to a great extent on the ecotype.

  7. Do pollinator distributions underlie the evolution of pollination ecotypes in the Cape shrub Erica plukenetii?

    Science.gov (United States)

    Van der Niet, Timotheüs; Pirie, Michael D; Shuttleworth, Adam; Johnson, Steven D; Midgley, Jeremy J

    2014-01-01

    According to the Grant-Stebbins model of pollinator-driven divergence, plants that disperse beyond the range of their specialized pollinator may adapt to a new pollination system. Although this model provides a compelling explanation for pollination ecotype formation, few studies have directly tested its validity in nature. Here we investigate the distribution and pollination biology of several subspecies of the shrub Erica plukenetii from the Cape Floristic Region in South Africa. We analyse these data in a phylogenetic context and combine these results with information on pollinator ranges to test whether the evolution of pollination ecotypes is consistent with the Grant-Stebbins model. Pollinator observations showed that the most common form of E. plukenetii with intermediate corolla length is pollinated by short-billed Orange-breasted sunbirds. Populations at the northern fringe of the distribution are characterized by long corollas, and are mainly pollinated by long-billed Malachite sunbirds. A population with short corollas in the centre of the range was mainly pollinated by insects, particularly short-tongued noctuid moths. Bird exclusion in this population did not have an effect on fruit set, while insect exclusion reduced fruit set. An analysis of floral scent across the range, using coupled gas chromatography-mass spectrometry, showed that the scent bouquets of flowers from moth-pollinated populations are characterized by a larger number of scent compounds and higher emission rates than those in bird-pollinated populations. This was also reflected in clear separation of moth- and bird-pollinated populations in a two-dimensional phenotype space based on non-metric multidimensional scaling analysis of scent data. Phylogenetic analyses of chloroplast and nuclear DNA sequences strongly supported monophyly of E. plukenetii, but not of all the subspecies. Reconstruction of ancestral character states suggests two shifts from traits associated with short

  8. Genome-scale cold stress response regulatory networks in ten Arabidopsis thaliana ecotypes

    DEFF Research Database (Denmark)

    Barah, Pankaj; Jayavelu, Naresh Doni; Rasmussen, Simon

    2013-01-01

    BACKGROUND: Low temperature leads to major crop losses every year. Although several studies have been conducted focusing on diversity of cold tolerance level in multiple phenotypically divergent Arabidopsis thaliana (A. thaliana) ecotypes, genome-scale molecular understanding is still lacking...... using Arabidopsis NimbleGen ATH6 microarrays. In total 6061 transcripts were significantly cold regulated (p ... be crucial for their local geographic adaptation to cold temperature. Additionally, since the approach presented here is general, it could be adapted to study networks regulating biological process in any biological systems....

  9. Ecotypic variability in the metabolic response of seeds to diurnal hydration-dehydration cycles and its relationship to seed vigor.

    Science.gov (United States)

    Bai, Bing; Sikron, Noga; Gendler, Tanya; Kazachkova, Yana; Barak, Simon; Grafi, Gideon; Khozin-Goldberg, Inna; Fait, Aaron

    2012-01-01

    Seeds in the seed bank experience diurnal cycles of imbibition followed by complete dehydration. These conditions pose a challenge to the regulation of germination. The effect of recurring hydration-dehydration (Hy-Dh) cycles were tested on seeds from four Arabidopsis thaliana accessions [Col-0, Cvi, C24 and Ler]. Diurnal Hy-Dh cycles had a detrimental effect on the germination rate and on the final percentage of germination in Col-0, Cvi and C24 ecotypes, but not in the Ler ecotype, which showed improved vigor following the treatments. Membrane permeability measured by ion conductivity was generally increased following each Hy-Dh cycle and was correlated with changes in the redox status represented by the GSSG/GSH (oxidized/reduced glutathione) ratio. Among the ecotypes, Col-0 seeds displayed the highest membrane permeability, whilst Ler was characterized by the greatest increase in electrical conductivity following Hy-Dh cycles. Following Dh 2 and Dh 3, the respiratory activity of Ler seeds significantly increased, in contrast to the other ecotypes, indicative of a dramatic shift in metabolism. These differences were associated with accession-specific content and patterns of change of (i) cell wall-related laminaribiose and mannose; (ii) fatty acid composition, specifically of the unsaturated oleic acid and α-linoleic acid; and (iii) asparagine, ornithine and the related polyamine putrescine. Furthermore, in the Ler ecotype the content of the tricarboxylic acid (TCA) cycle intermediates fumarate, succinate and malate increased in response to dehydration, in contrast to a decrease in the other three ecotypes. These findings provide a link between seed respiration, energy metabolism, fatty acid β-oxidation, nitrogen mobilization and membrane permeability and the improved germination of Ler seeds following Hy-Dh cycles.

  10. Problems with the claim of ecotype and taxon status of the wolf in the Great Lakes region

    Science.gov (United States)

    Cronin, Matthew A.; Mech, L. David

    2009-01-01

    Koblmuller et al. (2009) analysed molecular genetic data of the wolf in the Great Lakes (GL) region of the USA and concluded that the animal was a unique ecotype of grey wolf and that genetic data supported the population as a discrete wolf taxon. However, some of the literature that the researchers used to support their position actually did not, and additional confusion arises from indefinite use of terminology. Herein, we discuss the problems with designation of a wolf population as a taxon or ecotype without proper definition and assessment of criteria.

  11. Establishment of an Indirect Genetic Transformation Method for Arabidopsis thaliana ecotype Bangladesh

    Directory of Open Access Journals (Sweden)

    Bulbul AHMED

    2011-11-01

    Full Text Available Arabidopsis thaliana is a small flowering plant belonging to the Brassicaceae family, which is adopted as a model plant for genetic research. Agrobacterium tumifaciensmediated transformation method for A. thaliana ecotype Bangladesh was established. Leaf discs of A. thaliana were incubated with A. tumefaciens strain LBA4404 containing chimeric nos. nptII. nos and intron-GUS genes. Following inoculation and co-cultivation, leaf discs were cultured on selection medium containing 50 mg/l kanamycin + 50 mg/l cefotaxime + 1.5 mg/l NAA and kanamycin resistant shoots were induced from the leaf discs after two weeks. Shoot regeneration was achieved after transferring the tissues onto fresh medium of the same combination. Finally, the shoots were rooted on MS medium containing 50 mg/l kanamycin. Incorporation and expression of the transgenes were confirmed by PCR analysis. Using this protocol, transgenic A. thaliana plants can be obtained and indicates that genomic transformation in higher plants is possible through insertion of desired gene. Although Agrobacterium mediated genetic transformation is established for A. thaliana, this study was the conducted to transform A. thaliana ecotype Bangladesh.

  12. Ecotype evolution in Glossina palpalis subspecies, major vectors of sleeping sickness.

    Directory of Open Access Journals (Sweden)

    Thierry De Meeûs

    2015-03-01

    Full Text Available BACKGROUND: The role of environmental factors in driving adaptive trajectories of living organisms is still being debated. This is even more important to understand when dealing with important neglected diseases and their vectors. METHODOLOGY/PRINCIPAL FINDINGS: In this paper, we analysed genetic divergence, computed from seven microsatellite loci, of 614 tsetse flies (Glossina palpalis gambiensis and Glossina palpalis palpalis, major vectors of animal and human trypanosomes from 28 sites of West and Central Africa. We found that the two subspecies are so divergent that they deserve the species status. Controlling for geographic and time distances that separate these samples, which have a significant effect, we found that G. p. gambiensis from different landscapes (Niayes of Senegal, savannah and coastal environments were significantly genetically different and thus represent different ecotypes or subspecies. We also confirm that G. p. palpalis from Ivory Coast, Cameroon and DRC are strongly divergent. CONCLUSIONS/SIGNIFICANCE: These results provide an opportunity to examine whether new tsetse fly ecotypes might display different behaviour, dispersal patterns, host preferences and vectorial capacities. This work also urges a revision of taxonomic status of Glossina palpalis subspecies and highlights again how fast ecological divergence can be, especially in host-parasite-vector systems.

  13. Identification of Italian ecotypes of Juglans regia L. by molecular, morphological and biochemical markers

    Directory of Open Access Journals (Sweden)

    Pollegioni P

    2006-01-01

    Full Text Available Juglans regia L. is a multipurpose species important for quality wood and fruit production. In order to contrast the erosion and to properly conserve, manage and revaluate the genetic resources of Italian walnut, possible ecotypes, naturally adapted and still present in Italy have been researched. Leaves and fruits have been sampled in Campania region, localities of Montella, Cervinara, Fisciano, and in Abruzzo region, localities of Sulmona, Pescasseroli, Villetta Barrea, and Civitella Alfedena. The sites are located at different altitudes and climatic conditions. Materials have been collected on a total of 276 plants. Molecular, morphological and preliminary biochemical analyses have been carried out on this germplasm and on material belonging to 80 plants of 4 famous Italian walnut varieties (Bleggiana and Feltrina, North Italy; Sorrento and Malizia, Southern Italy, in order to have a comparison model. 134 ISSR, morphological and biochemical data have shown peculiar characters for Montella and Pescasseroli in comparison with the other accessions. Because of the peculiar environmental conditions of their locations, the effect of the temperature on the fruit development and fatty acid contents, it is possible to suppose that Montella and Pescasseroli are ecotypes which could be utilised as essential fat acid source and as material for afforestation of mountain zones.

  14. Evaluation of the defensive behavior of two honeybee ecotypes using a laboratory test

    Directory of Open Access Journals (Sweden)

    Andere Cecilia

    2002-01-01

    Full Text Available Honeybee defensive behavior is a useful selection criterion, especially in areas with Africanized honeybees (Apis mellifera L. In all genetic improvement programs the selected characters must be measured with precision, and because of this we evaluated a metabolic method for testing honeybee defensive behavior in the laboratory for its usefulness in distinguishing between honeybee ecotypes and selecting honeybees based on their level of defensive responses. Ten honeybee colonies were used, five having been produced by feral queens from a subtropical region supposedly colonized by Africanized honeybees and five by queens from a temperate region apparently colonized by European honeybees. We evaluate honeybee defensive behavior using a metabolic test based on oxygen consumption after stimulation with an alarm pheromone, measuring the time to the first response, time to maximum oxygen consumption, duration of activity, oxygen consumption at first response, maximum oxygen consumption and total oxygen consumption, colonies being ranked according to the values obtained for each variable. Significant (p < 0.05 differences were detected between ecotypes for each variable but for all variables the highest rankings were obtained for colonies of subtropical origin, which had faster and more intense responses. All variables were highly associated (p < 0.05. Total oxygen consumption was the best indicator of metabolic activity for defensive behavior because it combined oxygen consumption and the length of the response. This laboratory method may be useful for evaluating the defensive behavior of honey bees in genetic programs designed to select less defensive bees.

  15. Three-Dimensional Evaluation on Ecotypic Diversity of Traditional Chinese Medicine: A Case Study of Artemisia annua L.

    Science.gov (United States)

    Li, Lin; Josef, Brinckmann A; Liu, Bing; Zheng, Sihao; Huang, Linfang; Chen, Shilin

    2017-01-01

    Artemisinin is the first-line drug for anti-malaria recommended by the World Health Organization (WHO). As the sole natural plant source of artemisinin, ecotypes of Artemisia annua L. vary widely in artemisinin content between nations, and China is the main producing area of A. annua. Here we present a three-dimensional evaluation on ecotypic diversity of A. annua from 12 main producing areas in China using high-performance liquid chromatography coupled with evaporative light scattering detection (HPLC-ELSD) method, DNA barcoding and ecological analyses. The results indicated that A. annua exhibited high ecotypic diversity. A. annua grown in the South of the Qinling Mountains-Huaihe River Line had a high artemisinin content, whereas the northern ones were low. Similar pattern was noted in the genetic diversity. The southern A. annua had high intraspecific variation in contrast to the northern A. annua. In terms of ecological analyses, humidity and sunshine time could be the major limiting ecological factors that affect the accumulation of artemisinin. This is the first reported three-dimensional evaluation integrating chemical, molecular and ecological analyses of the ecotypic diversity of A. annua. The work will facilitate exploring the genetic basis of chemical variations and developing strategies for the breeding and cultivation of high quality A. annua.

  16. Flower stalk segments of Arabidopsis thaliana ecotype Columbia lack the capacity to grow in response to exogenously applied auxin.

    Science.gov (United States)

    Soga, K; Wakabayashi, K; Hoson, T; Kamisaka, S

    2000-12-01

    Exogenously applied IAA stimulated cell elongation of segments excised from flower stalks of Arabidopsis thaliana ecotype Landsberg erecta (Ler) by increasing the cell wall extensibility, but it did not affect that of ecotype Columbia (Col). Treatment with a low pH buffer solution (pH 4.0) or fusicoccin (FC), a reagent activating H(+)-ATPases, significantly increased the cell wall extensibility and promoted elongation growth of flower stalk segments of both ecotypes, indicating that the flower stalk segments of Col possess the capacity to grow under acidic pH conditions. IAA promoted the proton excretion in segments of Ler but not of Col. On the other hand, FC increased the proton excretion in segments of Col as much as that of Ler. These results suggest that IAA activates the plasma membrane H(+)-ATPases in the segments of Ler but not those of Col, while FC activates them in both ecotypes. Flower stalks of Col may lack the mechanisms of activation by IAA of the plasma membrane H(+)-ATPases.

  17. Quick divergence but slow convergence during ecotype formation in lake and stream stickleback pairs of variable age.

    Science.gov (United States)

    Lucek, K; Sivasundar, A; Kristjánsson, B K; Skúlason, S; Seehausen, O

    2014-09-01

    When genetic constraints restrict phenotypic evolution, diversification can be predicted to evolve along so-called lines of least resistance. To address the importance of such constraints and their resolution, studies of parallel phenotypic divergence that differ in their age are valuable. Here, we investigate the parapatric evolution of six lake and stream threespine stickleback systems from Iceland and Switzerland, ranging in age from a few decades to several millennia. Using phenotypic data, we test for parallelism in ecotypic divergence between parapatric lake and stream populations and compare the observed patterns to an ancestral-like marine population. We find strong and consistent phenotypic divergence, both among lake and stream populations and between our freshwater populations and the marine population. Interestingly, ecotypic divergence in low-dimensional phenotype space (i.e. single traits) is rapid and seems to be often completed within 100 years. Yet, the dimensionality of ecotypic divergence was highest in our oldest systems and only there parallel evolution of unrelated ecotypes was strong enough to overwrite phylogenetic contingency. Moreover, the dimensionality of divergence in different systems varies between trait complexes, suggesting different constraints and evolutionary pathways to their resolution among freshwater systems.

  18. Disentangling the role of phenotypic plasticity and genetic divergence in contemporary ecotype formation during a biological invasion.

    Science.gov (United States)

    Lucek, Kay; Sivasundar, Arjun; Seehausen, Ole

    2014-09-01

    The occurrence of contemporary ecotype formation through adaptive divergence of populations within the range of an invasive species typically requires standing genetic variation but can be facilitated by phenotypic plasticity. The relative contributions of both of these to adaptive trait differentiation have rarely been simultaneously quantified in recently diverging vertebrate populations. Here we study a case of intraspecific divergence into distinct lake and stream ecotypes of threespine stickleback that evolved in the past 140 years within the invasive range in Switzerland. Using a controlled laboratory experiment with full-sib crosses and treatments mimicking a key feature of ecotypic niche divergence, we test if the phenotypic divergence that we observe in the wild results from phenotypic plasticity or divergent genetic predisposition. Our experimental groups show qualitatively similar phenotypic divergence as those observed among wild adults. The relative contribution of plasticity and divergent genetic predisposition differs among the traits studied, with traits related to the biomechanics of feeding showing a stronger genetic predisposition, whereas traits related to locomotion are mainly plastic. These results implicate that phenotypic plasticity and standing genetic variation interacted during contemporary ecotype formation in this case.

  19. Investigating the Effect of Phosphorus, Potassium and Weed Management on Forage and Seed Yield of Alfalfa Ecotypes (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    Ali Reza Heidarian

    2012-09-01

    Full Text Available In order to investigate fertilizing and weed management effects on forage and seed yield of alfalfa ecotypes, a field trial was conducted during 2008-2009 growing season at Khorasan Agricultural and Natural Resource Research Center, Mashhad-Iran. Alfalfa ecotypes including (Ghareghozlo, Hoakmabad, Malekkandi, Kozre, Faminin, Galebani, Rahnani, Shorkat, Chaleshtar, Ghareaghaj, Gharoghlogh, Ordobad, Sedighan, Silvana, Sahandava, Ghahavand, Mohajerankaraj and Mashhad were allocated to main plots; sub plots consisted of two levels of none fertilizing and fertilization treatments using simultaneous application of potassium sulphate and phosphate triple at rates of 150 and 350 K/ha, respectively and sub-sub plots were allocated to weeding and none weeding treatments based on a complete randomized block design in a splitsplit- plot scheme with three replicates. Results showed that the effect of ecotype on forage yield was not significant. Gharoghlogh and Silvana produced the highest (18270 kg/ha and the lowest (14630 kg/ha green forage yield, respectively at both cuttings (first and second cuts. The interaction of fertilization and weeding on forage yield was significant (p<0.01. On the other hand, with application of fertilizer, forage yield 11.74% was increased and it was enhanced 26.93% by manual weeding. Furthermore, results revealed that ecotype fertilizer interaction was significant (p<0.05 for weed dry weight. Ecotype weeding interaction was significant (p<0.05 for number of seed per pod and seed weight (p<0.01. In addition, fertilizer weeding interaction was significant (p<0.05 for number of seed per plant. Among the treatments, highest number of seed per plant was produced by fertilizer and weeding treatment (2734 and the lowest one was obtained by non-fertilizer and non-weeding treatment (559.5.

  20. Convergent evolution across the Australian continent: ecotype diversification drives morphological convergence in two distantly related clades of Australian frogs.

    Science.gov (United States)

    Vidal-García, M; Keogh, J S

    2015-12-01

    Animals from different clades but subject to similar environments often evolve similar body shapes and physiological adaptations due to convergent evolution, but this has been rarely tested at the transcontinental level and across entire classes of animal. Australia's biome diversity, isolation and aridification history provide excellent opportunities for comparative analyses on broad-scale macroevolutionary patterns. We collected morphological and environmental data on eighty-four (98%) Australian hylid frog species and categorized them into ecotypes. Using a phylogenetic framework, we tested the hypothesis that frogs from the same ecotype display similar body shape patterns: (i) across all the Australian hylids, and (ii) through comparison with a similar previous study on 127 (97%) Australian myobatrachid species. Body size and shape variation did not follow a strong phylogenetic pattern and was not tightly correlated with environment, but there was a stronger association between morphotype and ecotype. Both arboreal and aquatic frogs had long limbs, whereas limbs of fossorial species were shorter. Other terrestrial species were convergent on the more typical frog body shape. We quantified the strength of morphological convergence at two levels: (i) between fossorial myobatrachid and hylid frogs, and (ii) in each ecomorph within the hylids. We found strong convergence within ecotypes, especially in fossorial species. Ecotypes were also reflected in physiological adaptations: both arboreal and cocooned fossorial frogs tend to have higher rates of evaporative water loss. Our results illustrate how adaptation to different ecological niches plays a crucial role in morphological evolution, boosting phenotypic diversity within a clade. Despite phylogenetic conservatism, morphological adaptation to repeatedly emerging new environments can erase the signature of ancestral morphotypes, resulting in phenotypic diversification and convergence both within and between diverse

  1. Identification of metalliferous ecotypes of Cistus ladanifer L. using RAPD markers.

    Science.gov (United States)

    Quintela-Sabarís, Celestino; Kidd, Petra S; Fraga, María Isabel

    2005-01-01

    The genetic diversity of Cistus ladanifer ssp. ladanifer (Cistaceae) growing on ultramafic and non-ultramafic (basic and schists) soils in the NE of Portugal was studied in order to identify molecular markers that could distinguish the metal-tolerant ecotypes of this species. Random Amplified Polymorphic DNA (RAPD) markers were used in order to estimate genetic variation and differences between populations. The RAPD dataset was analysed by means of a cluster analysis and an analysis of molecular variance (AMOVA). Our results indicate a significant partitioning of molecular variance between ultramafic and non-ultramafic populations of Cistus ladanifer, although the highest percentage of this variance was found at the intra-population level. Mantel's test showed no relationship between inter-population genetic and geographic distances. A series of RAPD bands that could be related to heavy metal tolerance were observed. The identification of such markers will enable the use of Cistus ladanifer in phytoremediation procedures.

  2. Identification of metalliferous ecotypes of Cistus ladanifer L. using RAPD markers

    Energy Technology Data Exchange (ETDEWEB)

    Quintela-Sabaris, C.; Fraga, M.I. [Dept. of Botany, Univ. of Santiago de Compostela (Spain); Kidd, P.S. [Dept. of Soil Science and Chemical Agronomy, Univ. of Santiago de Compostela (Spain)

    2005-04-01

    The genetic diversity of Cistus ladanifer ssp. ladanifer (Cistaceae) growing on ultramafic and non-ultramafic (basic and schists) soils in the NE of Portugal was studied in order to identify molecular markers that could distinguish the metal-tolerant ecotypes of this species. Random Amplified Polymorphic DNA (RAPD) markers were used in order to estimate genetic variation and differences between populations. The RAPD dataset was analysed by means of a cluster analysis and an analysis of molecular variance (AMOVA). Our results indicate a significant partitioning of molecular variance between ultramafic and non-ultramafic populations of Cistus ladanifer, although the highest percentage of this variance was found at the intra-population level. Mantel's test showed no relationship between inter-population genetic and geographic distances. A series of RAPD bands that could be related to heavy metal tolerance were observed. The identification of such markers will enable the use of Cistus ladanifer in phytoremediation procedures. (orig.)

  3. Ecotype-specific improvement of nitrogen status in European grasses after drought combined with rewetting

    Science.gov (United States)

    Arfin Khan, Mohammed A. S.; Kreyling, Juergen; Beierkuhnlein, Carl; Jentsch, Anke

    2016-11-01

    Drought stress and associated low soil moisture can decrease N status of forage plants by reducing nitrogen (N) uptake. Conversely, rainfall and associated favorable soil moisture can improve plant N status. Yet, it is unclear to which degree drought combined with rewetting can buffer negative effects of drought on N status of forage plants and their populations. Here, we compared shoot N status (N concentration, total N uptake and C/N ratio) of four temperate grass species. Particularly, we investigated ecotypes (populations) grown from seeds from four to six European provenances/species after a drought treatment combined with rewetting (10 day harvest delay) versus continuously watered conditions for control. The experimental combination of drought and rewetting significantly increased shoot N concentration (+96%), N uptake (+31%); and decreased C/N ratio (-46%), biomass production (-29%) and C concentration (-1.4%) compared to control. Shoot N status was found to be different between target grass species and also within their populations under drought combined with rewetting treatment. Presumably drought-adapted populations did not perform better than populations from moist sites indicating no evidence of local adaptation. The drought combined with rewetting event could buffer the negative effects of drought. Shoot N status of grasses after drought and rewetting even exceeded control plants. This surprising finding can potentially be explained by higher N uptake, lack of growth dilution effects or delayed plant maturation. Furthermore, within-species shoot N status responses to drought combined with rewetting event were ecotype-specific, hinting at diverse responses of different population. For rangeland management, we recommend that if a drought event occurs during the growing season, harvesting should be delayed beyond a following rain event.

  4. Defense responses in two ecotypes of Lotus japonicus against non-pathogenic Pseudomonas syringae.

    Directory of Open Access Journals (Sweden)

    Cesar D Bordenave

    Full Text Available Lotus japonicus is a model legume broadly used to study many important processes as nitrogen fixing nodule formation and adaptation to salt stress. However, no studies on the defense responses occurring in this species against invading microorganisms have been carried out at the present. Understanding how this model plant protects itself against pathogens will certainly help to develop more tolerant cultivars in economically important Lotus species as well as in other legumes. In order to uncover the most important defense mechanisms activated upon bacterial attack, we explored in this work the main responses occurring in the phenotypically contrasting ecotypes MG-20 and Gifu B-129 of L. japonicus after inoculation with Pseudomonas syringae DC3000 pv. tomato. Our analysis demonstrated that this bacterial strain is unable to cause disease in these accessions, even though the defense mechanisms triggered in these ecotypes might differ. Thus, disease tolerance in MG-20 was characterized by bacterial multiplication, chlorosis and desiccation at the infiltrated tissues. In turn, Gifu B-129 plants did not show any symptom at all and were completely successful in restricting bacterial growth. We performed a microarray based analysis of these responses and determined the regulation of several genes that could play important roles in plant defense. Interestingly, we were also able to identify a set of defense genes with a relative high expression in Gifu B-129 plants under non-stress conditions, what could explain its higher tolerance. The participation of these genes in plant defense is discussed. Our results position the L. japonicus-P. syringae interaction as a interesting model to study defense mechanisms in legume species.

  5. Salares versus coastal ecotypes of quinoa: Salinity responses in Chilean landraces from contrasting habitats.

    Science.gov (United States)

    Ruiz, Karina B; Aloisi, Iris; Del Duca, Stefano; Canelo, Valentina; Torrigiani, Patrizia; Silva, Herman; Biondi, Stefania

    2016-04-01

    Quinoa (Chenopodium quinoa Willd.) is a highly salt-tolerant species subdivided into five ecotypes and exhibiting broad intra-specific differences in tolerance levels. In a greenhouse study, Chilean landraces belonging either to the salares (R49) or coastal lowlands (VI-1, Villarrica) ecotype with contrasting agro-ecological origins were investigated for their responses to high salinity. The effects of two levels of salinity, 100 (T1) and 300 (T2) mM NaCl, on plant growth and on some physiological parameters were measured. Leaf and root Na(+) accumulation differed among landraces. T2 reduced growth and seed yield in all landraces with maximum inhibition relative to controls in R49. Salinity negatively affected chlorophyll and total polyphenol content (TPC) in VI-1 and Villarrica but not R49. Germination on saline or control media of seeds harvested from plants treated or not with NaCl was sometimes different; the best performing landrace was R49 insofar as 45-65% of seeds germinated on 500 mM NaCl-containing medium. In all landraces, average seedling root length declined strongly with increasing NaCl concentration, but roots of R49 were significantly longer than those of VI-1 and Villarrica up to 300 mM NaCl. Salt caused increases in seed TPC relative to controls, but radical scavenging capacity was higher only in seeds from T2 plants of R49. Total SDS-extractable seed proteins were resolved into distinct bands (10-70 kDa) with some evident differences between landraces. Salt-induced changes in protein patterns were landrace-specific. The responses to salinity of the salares landrace are discussed in relation to its better adaptation to an extreme environment.

  6. Differential control of seed primary dormancy in Arabidopsis ecotypes by the transcription factor SPATULA.

    Science.gov (United States)

    Vaistij, Fabián E; Gan, Yinbo; Penfield, Steven; Gilday, Alison D; Dave, Anuja; He, Zhesi; Josse, Eve-Marie; Choi, Giltsu; Halliday, Karen J; Graham, Ian A

    2013-06-25

    Freshly matured seeds exhibit primary dormancy, which prevents germination until environmental conditions are favorable. The establishment of dormancy occurs during seed development and involves both genetic and environmental factors that impact on the ratio of two antagonistic phytohormones: abscisic acid (ABA), which promotes dormancy, and gibberellic acid, which promotes germination. Although our understanding of dormancy breakage in mature seeds is well advanced, relatively little is known about the mechanisms involved in establishing dormancy during seed maturation. We previously showed that the SPATULA (SPT) transcription factor plays a key role in regulating seed germination. Here we investigate its role during seed development and find that, surprisingly, it has opposite roles in setting dormancy in Landsberg erecta and Columbia Arabidopsis ecotypes. We also find that SPT regulates expression of five transcription factor encoding genes: ABA-INSENSITIVE4 (ABI4) and ABI5, which mediate ABA signaling; REPRESSOR-OF-GA (RGA) and RGA-LIKE3 involved in gibberellic acid signaling; and MOTHER-OF-FT-AND-TFL1 (MFT) that we show here promotes Arabidopsis seed dormancy. Although ABI4, RGA, and MFT are repressed by SPT, ABI5 and RGL3 are induced. Furthermore, we show that RGA, MFT, and ABI5 are direct targets of SPT in vivo. We present a model in which SPT drives two antagonistic "dormancy-repressing" and "dormancy-promoting" routes that operate simultaneously in freshly matured seeds. Each of these routes has different impacts and this in turn explains the opposite effect of SPT on seed dormancy of the two ecotypes analyzed here.

  7. Expression and functional analysis of metal transporter genes in two contrasting ecotypes of the hyperaccumulator Thlaspi caerulescens.

    Science.gov (United States)

    Plaza, Sonia; Tearall, Kathryn L; Zhao, Fang-Jie; Buchner, Peter; McGrath, Steve P; Hawkesford, Malcolm J

    2007-01-01

    Zinc (Zn) hyperaccumulation is a constitutive property of Thlaspi caerulescens, whereas cadmium (Cd) hyperaccumulation varies greatly among different ecotypes. The molecular basis of this variation is unknown. Ecotypic differences in the sequences and expression of four representative ZIP family transporter genes were investigated. Genome analysis indicated the presence of at least two closely related copies of the TcIRT1 gene in both Ganges (high Cd accumulating) and Prayon (low Cd accumulating) ecotypes, with different copies being expressed in each, and, furthermore, the two genes potentially encode different length transcripts. The predominant transcript in Prayon was truncated, missing sequence coding for the putative metal-binding site and the five C-terminal transmembrane helices. The two ecotypes were grown hydroponically +/-Fe and Cd, and mRNA abundance determined for four ZIP genes. The four ZIP genes studied (TcIRT1, TcIRT2, TcZNT1, and TcZNT5) were expressed in roots only. TcIRT1 expression (full-length in Ganges, TcIRT1-1G; truncated in Prayon, TcIRT1-2P) was enhanced by Fe deficiency or by exposure to Cd. TcIRT2 expression was induced by Fe deficiency, but was unaffected by Cd exposure. TcZNT5-G showed greater expression in Prayon compared with Ganges. The functions of TcIRT1 from Ganges and Prayon and the Arabidopsis homologue were analysed by heterologous expression in yeast. All three IRT1 genes were able to facilitate growth on low Fe concentrations. Cd sensitivity of yeast was conferred in the order AtIRT1>TcIRT1-1G>TcIRT1-2P (truncated). Cd uptake after 4 h was only detectable following complementation by AtIRT1. The results suggest that although TcIRT1-G may be involved in Cd hyperaccumulation in the Ganges ecotype of T. caerulescens, the transporter expressed in yeast does not have an enhanced ability to transport Cd compared with AtIRT1. Therefore, the unique Cd-accumulating ability of the T. caerulescens Ganges ecotype must be due to the

  8. Habitat Temperature and Precipitation of Arabidopsis thaliana Ecotypes Determine the Response of Foliar Vasculature, Photosynthesis, and Transpiration to Growth Temperature.

    Science.gov (United States)

    Adams, William W; Stewart, Jared J; Cohu, Christopher M; Muller, Onno; Demmig-Adams, Barbara

    2016-01-01

    Acclimatory adjustments of foliar vascular architecture, photosynthetic capacity, and transpiration rate in Arabidopsis thaliana ecotypes (Italian, Polish [Col-0], Swedish) were characterized in the context of habitat of origin. Temperatures of the habitat of origin decreased linearly with increasing habitat latitude, but habitat precipitation was greatest in Italy, lowest in Poland, and intermediate in Sweden. Plants of the three ecotypes raised under three different growth temperature regimes (low, moderate, and high) exhibited highest photosynthetic capacities, greatest leaf thickness, highest chlorophyll a/b ratio and levels of β-carotene, and greatest levels of wall ingrowths in phloem transfer cells, and, in the Col-0 and Swedish ecotypes, of phloem per minor vein in plants grown at the low temperature. In contrast, vein density and minor vein tracheary to sieve element ratio increased with increasing growth temperature - most strongly in Col-0 and least strongly in the Italian ecotype - and transpirational water loss correlated with vein density and number of tracheary elements per minor vein. Plotting of these vascular features as functions of climatic conditions in the habitat of origin suggested that temperatures during the evolutionary history of the ecotypes determined acclimatory responses of the foliar phloem and photosynthesis to temperature in this winter annual that upregulates photosynthesis in response to lower temperature, whereas the precipitation experienced during the evolutionary history of the ecotypes determined adjustment of foliar vein density, xylem, and transpiration to temperature. In particular, whereas photosynthetic capacity, leaf thickness, and foliar minor vein phloem features increased linearly with increasing latitude and decreasing temperature of the habitats of origin in response to experimental growth at low temperature, transpiration rate, foliar vein density, and minor vein tracheary element numbers and cross

  9. Habitat temperature and precipitation of Arabidopsis thaliana ecotypes determine the response of foliar vasculature, photosynthesis, and transpiration to growth temperature

    Directory of Open Access Journals (Sweden)

    William Walter Adams III

    2016-07-01

    Full Text Available Acclimatory adjustments of foliar vascular architecture, photosynthetic capacity, and transpiration rate in Arabidopsis thaliana ecotypes (Italian, Polish [Col-0], Swedish were characterized in the context of habitat of origin. Temperatures of the habitat of origin decreased linearly with increasing habitat latitude, but habitat precipitation was greatest in Italy, lowest in Poland, and intermediate in Sweden. Plants of the three ecotypes raised under three different growth temperature regimes (low, moderate, and high exhibited highest photosynthetic capacities, greatest leaf thickness, highest chlorophyll a/b ratio and levels of β-carotene, and greatest levels of wall ingrowths in phloem transfer cells, and, in the Col-0 and Swedish ecotypes, of phloem per minor vein in plants grown at the low temperature. In contrast, vein density and minor vein tracheary to sieve element ratio increased with increasing growth temperature – most strongly in Col-0 and least strongly in the Italian ecotype – and transpirational water loss correlated with vein density and number of tracheary elements per minor vein. Plotting of these vascular features as functions of climatic conditions in the habitat of origin suggested that temperatures during the evolutionary history of the ecotypes determined acclimatory responses of the foliar phloem and photosynthesis to temperature in this winter annual that upregulates photosynthesis in response to lower temperature, whereas the precipitation experienced during the evolutionary history of the ecotypes determined adjustment of foliar vein density, xylem, and transpiration to temperature. In particular, whereas photosynthetic capacity, leaf thickness, and foliar minor vein phloem features increased linearly with increasing latitude and decreasing temperature of the habitats of origin in response to experimental growth at low temperature, transpiration rate, foliar vein density, and minor vein tracheary element numbers

  10. Association between minor loading vein architecture and light- and CO2-saturated rates of photosynthetic oxygen evolution among Arabidopsis thaliana ecotypes from different latitudes

    Directory of Open Access Journals (Sweden)

    Christopher M Cohu

    2013-07-01

    Full Text Available Through microscopic analysis of veins and assessment of light- and CO2-saturated rates of photosynthetic oxygen evolution, we investigated the relationship between minor loading vein anatomy and photosynthesis of mature leaves in three ecotypes of Arabidopsis thaliana grown under four different combinations of temperature and photon flux density (PFD. All three ecotypes exhibited greater numbers and cross-sectional area of phloem cells as well as higher photosynthesis rates in response to higher PFD and especially lower temperature. The Swedish ecotype exhibited the strongest response to these conditions, the Italian ecotype the weakest response, and the Col-0 ecotype exhibited an intermediate response. Among all three ecotypes, strong linear relationships were found between light- and CO2-saturated rates of photosynthetic oxygen evolution and the number and area of either sieve elements or of companion and phloem parenchyma cells in foliar minor loading veins, with the Swedish ecotype showing the highest number of cells in minor loading veins (and largest minor veins coupled with unprecedented high rates of photosynthesis. Linear, albeit less significant, relationships were also observed between number and cross-sectional area of tracheids per minor loading vein versus light- and CO2-saturated rates of photosynthetic oxygen evolution. We suggest that sugar distribution infrastructure in the phloem is co-regulated with other features that set the upper limit for photosynthesis. The apparent genetic differences among Arabidopsis ecotypes should allow for future identification of the gene(s involved in augmenting sugar-loading and -transporting phloem cells and maximal rates of photosynthesis.

  11. The evolving male: spinner dolphin (Stenella longirostris) ecotypes are divergent at Y chromosome but not mtDNA or autosomal markers.

    Science.gov (United States)

    Andrews, Kimberly R; Perrin, William F; Oremus, Marc; Karczmarski, Leszek; Bowen, Brian W; Puritz, Jonathan B; Toonen, Robert J

    2013-05-01

    The susceptibility of the Y chromosome to sexual selection may make this chromosome an important player in the formation of reproductive isolating barriers, and ultimately speciation. Here, we investigate the role of the Y chromosome in phenotypic divergence and reproductive isolation of spinner dolphin (Stenella longirostris) ecotypes. This species contains six known ecotypes (grouped into four subspecies) that exhibit striking differences in morphology, habitat and mating system, despite having adjacent or overlapping ranges and little genetic divergence at previously studied mtDNA and autosomal markers. We examined the phylogeographic structure for all six ecotypes across the species range (n = 261, 17 geographic locations) using DNA sequences from three Y chromosome markers, two maternally inherited mitochondrial (mtDNA) markers, and a biparentally inherited autosomal intron. mtDNA and autosomal analyses revealed low divergence (most Φ(ST) values <0.1) between ecotypes and geographic regions, concordant with previous studies. In contrast, Y intron analyses revealed fixed differences amongst the three most phenotypically divergent groups: S. l. longirostris vs. S. l. roseiventris vs. combined S. l. orientalis/S. l. centroamericana/Tres Marias ecotypes). Another ecotype (whitebelly), previously postulated to be a hybrid between the two phenotypically most divergent ecotypes, had Y haplotypes from both putative parent ecotypes, supporting a hybrid designation. Reduced introgression of the Y chromosome has previously been observed in other organisms ranging from insects to terrestrial mammals, and here we demonstrate this phenomenon in a marine mammal with high dispersal capabilities. These results indicate that reduced introgression of the Y chromosome occurs in a wide taxonomic range of organisms and support the growing body of evidence that rapid evolution of the Y chromosome is important in evolutionary diversification.

  12. Effects of Nano Fertilizer Application and Maternal Corm Weight on Flowering at Some Saffron (Crocus sativus L.) Ecotypes

    OpenAIRE

    AMIRNIA, Reza; Bayat, Mahdi; TAJBAKHSH, Mahdi

    2014-01-01

    To develop saffron planting in Urmia, West Azerbaijan, Iran, a split-split plot experiment based on CRBD was carried out in the Urmia University's research farm for two years . Nanofertilizers (Fe, P, K and nofertilizer (control)) as main plots, saffron ecotypes (Mashhad, Torbat-Heydarieh, Torbat-jam, Gonabad, Ghaen and Birjand) as subplots and maternal corm weight (6, 8, 10 and 12 g) as sub-sub plots were considered. Throughout the two years of the study, results showed significant differenc...

  13. A comparison of the functional traits of common reed (Phragmites australis in northern China: aquatic vs. terrestrial ecotypes.

    Directory of Open Access Journals (Sweden)

    Liping Li

    Full Text Available Common reed (Phragmites australis (Cav. Trin. ex Steud. is distributed widely throughout the world with various ecotypes. This research compares the functional traits and biomass allocation patterns of two contrasting reed ecotypes. Twelve pairs of aquatic and terrestrial reed samples were collected in northern China. Significant differences in functional traits between the two reed ecotypes were observed, while biomass allocation patterns of reed organs did not differ significantly except for at the root. The dry matter content (DMC in the whole of the reed plant, leaf, root, and rhizome was higher; while the specific leaf area (SLA and specific root length (SRL were lower in terrestrial versus aquatic reed. The biomass allocation in organs of the two forms of reed was isometric, only root in the terrestrial habitat increased faster with an increase in the whole plant biomass. It can be affirmed that aquatic and terrestrial reed that adapt to different environments generally has distinct leaf and root functional traits but isometric biomass allocation patterns. This suggests different resource acquisition strategies: (1 aquatic reed grows faster with high SLA and SRL and is more responsive to the environment, while (2 terrestrial reed with high DMC grows slower and is less responsive to the adverse environment (e.g. dry soil conditions.

  14. A comparison of the functional traits of common reed (Phragmites australis) in northern China: aquatic vs. terrestrial ecotypes.

    Science.gov (United States)

    Li, Liping; Han, Wenxuan; Thevs, Niels; Jia, Xiuhong; Ji, Chengjun; Jin, Dongmei; He, Ping; Schmitt, Armin O; Cirella, Giuseppe Tommaso; Zerbe, Stefan

    2014-01-01

    Common reed (Phragmites australis (Cav.) Trin. ex Steud.) is distributed widely throughout the world with various ecotypes. This research compares the functional traits and biomass allocation patterns of two contrasting reed ecotypes. Twelve pairs of aquatic and terrestrial reed samples were collected in northern China. Significant differences in functional traits between the two reed ecotypes were observed, while biomass allocation patterns of reed organs did not differ significantly except for at the root. The dry matter content (DMC) in the whole of the reed plant, leaf, root, and rhizome was higher; while the specific leaf area (SLA) and specific root length (SRL) were lower in terrestrial versus aquatic reed. The biomass allocation in organs of the two forms of reed was isometric, only root in the terrestrial habitat increased faster with an increase in the whole plant biomass. It can be affirmed that aquatic and terrestrial reed that adapt to different environments generally has distinct leaf and root functional traits but isometric biomass allocation patterns. This suggests different resource acquisition strategies: (1) aquatic reed grows faster with high SLA and SRL and is more responsive to the environment, while (2) terrestrial reed with high DMC grows slower and is less responsive to the adverse environment (e.g. dry soil conditions).

  15. Effects of cadmium on ultrastructure and antioxidative defense system in hyperaccumulator and non-hyperaccumulator ecotypes of Sedum alfredii Hance

    Energy Technology Data Exchange (ETDEWEB)

    Jin Xiaofen [Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, Zhejiang University, Hangzhou 310029 (China); Zhejiang Provincial Key Lab of Subtropical Soil Science and Plant Nutrition, College of Environmental and Natural Resources Science, Zhejiang University, Hangzhou 310029 (China); Yang Xiaoe [Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, Zhejiang University, Hangzhou 310029 (China); Zhejiang Provincial Key Lab of Subtropical Soil Science and Plant Nutrition, College of Environmental and Natural Resources Science, Zhejiang University, Hangzhou 310029 (China)], E-mail: xyang@zju.edu.cn; Islam, Ejazul [Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, Zhejiang University, Hangzhou 310029 (China); Zhejiang Provincial Key Lab of Subtropical Soil Science and Plant Nutrition, College of Environmental and Natural Resources Science, Zhejiang University, Hangzhou 310029 (China); Nuclear Institute of Agriculture, Tandojam 48800, Hyderabad (Pakistan); Liu Dan [School of Tourism and Health, Zhejiang Forestry College, 311300 Lin' an (China); Mahmood, Qaisar [Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, Zhejiang University, Hangzhou 310029 (China); Zhejiang Provincial Key Lab of Subtropical Soil Science and Plant Nutrition, College of Environmental and Natural Resources Science, Zhejiang University, Hangzhou 310029 (China)

    2008-08-15

    Plant growth, ultrastructural and antioxidant adaptations and glutathione biosynthesis in Cd-hyperaccumulating ecotype Sedum alfredii Hance (HE) countering high Cd environment were investigated and compared with its non Cd-hyperaccumulating ecotype (NHE). Cadmium exposure resulted in significant ultrastructural changes in root meristem and leaf mesophyll cells of S. alfredii, but damage was more pronounced in NHE even when Cd concentrations were one-tenth of those applied to HE. Cadmium stress damaged chloroplasts causing imbalanced lamellae formation coupled with early leaf senescence. Histochemical results revealed that glutathione (GSH) biosynthesis inhibition led to overproduction of hydrogen peroxide (H{sub 2}O{sub 2}) and superoxide radical (O{sub 2}{center_dot}{sup -}) in HE but not in NHE. Differences were noted in both HE and NHE for catalase (CAT), guaiacol peroxidase (GPX), ascorbate peroxidase (APX) and glutathione reductase (GR) activities under various Cd stress levels. No relationship was found between antioxidative defense capacity including activities of superoxide dismutase (SOD), CAT, GPX, APX and GR as well as ascorbic acid (AsA) contents and Cd tolerance in the two ecotypes of S. alfredii. The GSH biosynthesis induction in root and shoot exposed to elevated Cd conditions may be involved in Cd tolerance and hyperaccumulation in HE of S. alfredii H.

  16. A study of fluctuating asymmetry in hybrids of dwarf and normal lake whitefish ecotypes (Coregonus clupeaformis) from different glacial races.

    Science.gov (United States)

    Lu, G; Bernatchez, L

    1999-12-01

    Fish ecotypes found in north temperate lakes are increasingly used as model organisms to explore patterns and processes of population divergence that may ultimately cause speciation. Processes involved in their reproductive isolation are, however, still poorly understood. Recent experimental studies on whitefish ecotypes from different glacial races revealed that embryonic mortality of hybrids was 2.4-4.7 times higher than for parental forms. In this study, we compared fluctuating asymmetry (FA) in morphological traits of these same hybrid and pure crosses to test the hypothesis that genetic stress observed in hybrids at embryonic stages is also manifested at later developmental stages. Twelve morphological traits were used to measure asymmetry. Variable degrees of asymmetry were observed depending on traits and crosses, however there was no significant difference in FA among crosses. These results thus provided no evidence in support of the working hypothesis and indicated that genetic stress may differ among life stages. It is more likely that high hybrid embryonic mortality acts together with ecological factors at later stages to increase further the extent of reproductive isolation between sympatric whitefish ecotypes.

  17. Northern ragweed ecotypes flower earlier and longer in response to elevated CO2: what are you sneezing at?

    Science.gov (United States)

    Stinson, Kristina A; Albertine, Jennifer M; Hancock, Laura M S; Seidler, Tristram G; Rogers, Christine A

    2016-10-01

    Significant changes in plant phenology and flower production are predicted over the next century, but we know relatively little about geographic patterns of this response in many species, even those that potentially impact human wellbeing. We tested for variation in flowering responses of the allergenic plant, Ambrosia artemisiifolia (common ragweed). We grew plants originating from three latitudes in the Northeastern USA at experimental levels of CO2 (400, 600, and 800 µL L(-1)). We hypothesized that northern ecotypes adapted to shorter growing seasons would flower earlier than their southern counterparts, and thus disproportionately allocate carbon gains from CO2 to reproduction. As predicted, latitude of origin and carbon dioxide level significantly influenced the timing and magnitude of flowering. Reproductive onset occurred earlier with increasing latitude, with concurrent increases in the number of flowers produced. Elevated carbon dioxide resulted in earlier reproductive onset in all ecotypes, which was significantly more pronounced in the northern populations. We interpret our findings as evidence for ecotypic variation in ragweed flowering time, as well in responses to CO2. Thus, the ecological and human health implications of common ragweed's response to global change are likely to depend on latitude. We conclude that increased flower production, duration, and possibly pollen output, can be expected in Northeastern United States with rising levels of CO2. The effects are likely, however, to be most significant in northern parts of the region.

  18. Identification of ecotype-specific marker genes for categorization of beer-spoiling Lactobacillus brevis.

    Science.gov (United States)

    Behr, Jürgen; Geissler, Andreas J; Preissler, Patrick; Ehrenreich, Armin; Angelov, Angel; Vogel, Rudi F

    2015-10-01

    The tolerance to hop compounds, which is mainly associated with inhibition of bacterial growth in beer, is a multi-factorial trait. Any approaches to predict the physiological differences between beer-spoiling and non-spoiling strains on the basis of a single marker gene are limited. We identified ecotype-specific genes related to the ability to grow in Pilsner beer via comparative genome sequencing. The genome sequences of four different strains of Lactobacillus brevis were compared, including newly established genomes of two highly hop tolerant beer isolates, one strain isolated from faeces and one published genome of a silage isolate. Gene fragments exclusively occurring in beer-spoiling strains as well as sequences only occurring in non-spoiling strains were identified. Comparative genomic arrays were established and hybridized with a set of L. brevis strains, which are characterized by their ability to spoil beer. As result, a set of 33 and 4 oligonucleotide probes could be established specifically detecting beer-spoilers and non-spoilers, respectively. The detection of more than one of these marker sequences according to a genetic barcode enables scoring of L. brevis for their beer-spoiling potential and can thus assist in risk evaluation in brewing industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Induction of cell death by graphene in Arabidopsis thaliana (Columbia ecotype) T87 cell suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Begum, Parvin, E-mail: parvinchy@ees.hokudai.ac.jp; Fugetsu, Bunshi

    2013-09-15

    Highlights: • This study was set up to explore potential influence of graphene on T87 cells. • Fragmented nuclei, membrane damage, mitochondrial dysfunction were observed. • ROS increased, ROS are key mediators in the cell death signaling pathway. • Translocation of graphene into cells and an endocytosis-like structure was observed. • Graphene entering into the cells by endocytosis. -- Abstract: The toxicity of graphene on suspensions of Arabidopsis thaliana (Columbia ecotype) T87 cells was investigated by examining the morphology, mitochondrial dysfunction, reactive oxygen species generation (ROS), and translocation of graphene as the toxicological endpoints. The cells were grown in Jouanneau and Péaud-Lenoel (JPL) media and exposed to graphene at concentrations 0–80 mg/L. Morphological changes were observed by scanning electron microscope and the adverse effects such as fragmented nuclei, membrane damage, mitochondrial dysfunction was observed with fluorescence microscopy by staining with Hoechst 33342/propidium iodide and succinate dehydrogenase (mitochondrial bioenergetic enzyme). Analysis of intracellular ROS by 2′,7′-dichlorofluorescein diacetate demonstrated that graphene induced a 3.3-fold increase in ROS, suggesting that ROS are key mediators in the cell death signaling pathway. Transmission electron microscopy verified the translocation of graphene into cells and an endocytosis-like structure was observed which suggested graphene entering into the cells by endocytosis. In conclusion, our results show that graphene induced cell death in T87 cells through mitochondrial damage mediated by ROS.

  20. Global gene expression of Prochlorococcus ecotypes in response to changes in nitrogen availability.

    Science.gov (United States)

    Tolonen, Andrew C; Aach, John; Lindell, Debbie; Johnson, Zackary I; Rector, Trent; Steen, Robert; Church, George M; Chisholm, Sallie W

    2006-01-01

    Nitrogen (N) often limits biological productivity in the oceanic gyres where Prochlorococcus is the most abundant photosynthetic organism. The Prochlorococcus community is composed of strains, such as MED4 and MIT9313, that have different N utilization capabilities and that belong to ecotypes with different depth distributions. An interstrain comparison of how Prochlorococcus responds to changes in ambient nitrogen is thus central to understanding its ecology. We quantified changes in MED4 and MIT9313 global mRNA expression, chlorophyll fluorescence, and photosystem II photochemical efficiency (Fv/Fm) along a time series of increasing N starvation. In addition, the global expression of both strains growing in ammonium-replete medium was compared to expression during growth on alternative N sources. There were interstrain similarities in N regulation such as the activation of a putative NtcA regulon during N stress. There were also important differences between the strains such as in the expression patterns of carbon metabolism genes, suggesting that the two strains integrate N and C metabolism in fundamentally different ways.

  1. Switchgrass Cultivar/Ecotype Selection and Management for Biofuels in the Upper Southeast USA

    Directory of Open Access Journals (Sweden)

    Rocky Lemus

    2014-01-01

    Full Text Available Switchgrass (Panicum virgatum L., a perennial warm-season grass indigenous to the eastern USA, has potential as a biofuels feedstock. The objective of this study was to investigate the performance of upland and lowland switchgrass cultivars under different environments and management treatments. Four cultivars of switchgrass were evaluated from 2000 to 2001 under two management regimes in plots established in 1992 at eight locations in the upper southeastern USA. Two management treatments included 1 a single annual harvest (in late October to early November and a single application of 50 kg N/ha/yr and 2 two annual harvests (in midsummer and November and a split application of 100 kg N/ha/yr. Biomass yields averaged 15 Mg/ha/yr and ranged from 10 to 22 Mg/ha/yr across cultivars, managements, locations, and years. There was no yield advantage in taking two harvests of the lowland cultivars (Alamo and Kanlow. When harvested twice, upland cultivars (Cave-in-Rock and Shelter provided yields equivalent to the lowland ecotypes. Tiller density was 36% lower in stands cutting only once per year, but the stands appeared vigorous after nine years of such management. Lowland cultivars and a one-cutting management (after the tops have senesced using low rates of applied N (50 kg/ha are recommended.

  2. Diversity of thermal ecotypes and potential pathotypes of Bacillus thuringiensis soil isolates.

    Science.gov (United States)

    Swiecicka, Izabela; Bartoszewicz, Marek; Kasulyte-Creasey, Daiva; Drewnowska, Justyna M; Murawska, Emilia; Yernazarova, Aliya; Lukaszuk, Edyta; Mahillon, Jacques

    2013-08-01

    Ecological diversification of Bacillus thuringiensis soil isolates was examined to determine whether bacteria adapted to grow at low temperature and/or potentially pathogenic correspond to genetically distinct lineages. Altogether, nine phylogenetic lineages were found among bacilli originating from North-Eastern Poland (n = 24) and Lithuania (n = 25) using multi-locus sequence typing. This clustering was chiefly confirmed by pulsed-field gel electrophoresis. One third of the bacilli were found to be psychrotolerant, which strongly supports the hypothesis of the existence of thermal ecotypes among B. thuringiensis. PCR screening was also performed to detect potential enterotoxin genes and Bacillus anthracis pXO1- and pXO2-like replicons. The cytK-positive isolates (22%) were significantly associated with two phylogenetic lineages (potential CytK pathotypes), whereas there was no correlation between phylogenetic grouping and the presence of the potential tripartite enterotoxin pathotypes (86% of strains). A statistically significant association between phylogenetic lineages and ecologic properties was found with regard to the cry1-positive Lithuanian isolates, while the cry genes in Polish isolates and the pXO1- and pXO2 replicon-like elements showed scattered distribution across phylogenetic lineages. Our results support the hypothesis that B. thuringiensis comprises strains belonging to different phylogenetic lineages, which exhibit specific ecological properties.

  3. Investigation of the effect of phosphogypsum amendment on two Arabidopsis thaliana ecotype growth and development.

    Science.gov (United States)

    Ayadi, Amal; Chorriba, Amal; Fourati, Amine; Gargouri-Bouzid, Radhia

    2015-01-01

    The production of phosphoric acid from natural phosphate rock leads to an industrial waste called phosphogypsum (PG). About 5 tons of PG are generated per ton of phosphoric acid produced. This acidic waste (pH 2.2) is mostly disposed of by dumping into large stockpiles close to fertilizer production units, where they occupy large land areas that can cause serious environmental damages. Several attempts were made to test PG valorization via soil amendment because of its phosphate, sulphate and calcium content. The aim of the this study was to evaluate the potential use of PG as phosphate amendment in soil using two wild-type Arabidopsis thaliana ecotypes (Wassilewskija and Colombia) as model plants. Plants were grown in a greenhouse for 30 days, on substrates containing various PG concentrations (0%, 15%, 25%, 40% and 50%). The growth rate and physiological parameters (fresh weight, phosphate and chlorophyll content) were determined. The data revealed that 15% PG did not alter plant survival and leaf's dry weight, and the inorganic phosphate (Pi) uptake by plant seemed to be efficient. However, some alterations in Chlorophyll a/Chlorophyll b ratio were noticed. Higher PG concentrations (40 and 50% PG) exhibited an enhanced negative effect on plant growth, survival and Pi uptake. These inhibitory effects of the substrates may be related to the acidity of the medium in addition to its Cd content.

  4. Rapid evolutionary divergence and ecotypic diversification of germination behavior in weedy rice populations.

    Science.gov (United States)

    Xia, Han-Bing; Xia, Hui; Ellstrand, Norman C; Yang, Chao; Lu, Bao-Rong

    2011-09-01

    Feral plants have evolved from well-studied crops, providing good systems for elucidation of how weediness evolves. As yet, they have been largely neglected for this purpose. The evolution of weediness can occur by simple back mutations in domestication genes (domestication in reverse). Whether the evolutionary steps to weediness always occur in reverse remains largely unknown. We examined seed germination behavior in recently evolved weedy rice (Oryza sativa f. spontanea) populations and their coexisting cultivars in eastern and north-eastern China to address whether 'dedomestication' is the simple reverse of domestication. We found that these weedy populations did not diverge from their progenitors by reverting to the pre-domestication trait of seed dormancy. Instead, they have evolved a novel mechanism to avoid growing in inappropriate environments via changes in critical temperature cues for seed germination. Furthermore, we found evidence for subsequent ecotypic divergence of these populations such that the critical temperature for germination correlates with the local habitat temperature at latitudinal gradients. The origins of problematic plant species, weeds and invasives, have already been studied in detail. These plants can thus be used as systems for studying rapid evolution. To determine whether and how that evolution is adaptive, experiments such as those described here can be performed.

  5. Identifying Differences in Abiotic Stress Gene Networks between Lowland and Upland Ecotypes of Switchgrass (DE-SC0008338)

    Energy Technology Data Exchange (ETDEWEB)

    Childs, Kevin [Michigan State Univ., East Lansing, MI (United States); Buell, Robin [Michigan State Univ., East Lansing, MI (United States); Zhao, Bingyu [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Zhang, Xunzhong [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2016-11-10

    Switchgrass (Panicum virgatum) is a warm-season C4 grass that is a target lignocellulosic biofuel species for use in the United States due to its local adaption capabilities and high biomass accumulation. Two ecotypes of switchgrass have been described. Members of the lowland ecotype are taller, have narrower leaf blades and generate more biomass compared to individuals from the upland ecotype. Additionally, lowland plants are generally found in the southern United States while upland switchgrass is more typically present in the northern United States. These differences are important as it is envisioned that switchgrass for biofuel production will typically be grown on marginal lands in the northern United States to supplement and diversify farmers' traditional crop incomes. While lowland switchgrass is more productive, it has poor winter survivability in northern latitudes where upland switchgrass is expected to be grown for biofuel use. Abiotic stresses likely to be encountered by switchgrass include drought and salinity. Despite initially being described as preferring wetter environments, members of the lowland ecotype have been characterized as being more drought tolerant than plants of the upland ecotype. Nonetheless, direct trials have indicated that variation for drought tolerance exists in both ecotypes, but prior to this project, only a relatively small number of switchgrass lines had been tested for drought responses. Similarly, switchgrass cultivars have not been widely tested for salt tolerance, but a few studies have shown that even mild salt stress can inhibit growth. The effects of drought and salt stress on plant growth are complex. Both drought and salinity affect the osmotic potential of plant cells and negatively affect plant growth due to reduced water potential and reduced photosynthesis that results from lower stomatal conductance of CO2. Plants respond to drought and salt stress by activating genes that directly attempt to

  6. Comparative assessment on the prevalence of mutations in the Plasmodium falciparum drug-resistant genes in two different ecotypes of Odisha state, India.

    Science.gov (United States)

    Kar, Narayani Prasad; Chauhan, Kshipra; Nanda, Nutan; Kumar, Ashwani; Carlton, Jane M; Das, Aparup

    2016-07-01

    Considering malaria as a local and focal disease, epidemiological understanding of different ecotypes of malaria can help in devising novel control measures. One of the major hurdles in malaria control lies on the evolution and dispersal of the drug-resistant malaria parasite, Plasmodium falciparum. We herewith present data on genetic variation at the Single Nucleotide Polymorphism (SNP) level in four different genes of P. falciparum (Pfcrt, Pfmdr1, Pfdhfr, and Pfdhps) that confer resistance to different antimalarials in two different eco-epidemiological settings, i.e. Hilly-Forest (HF) and Riverine-Plain (RP), in a high malaria endemic district of Odisha state, India. Greater frequency of antimalarial resistance conferring SNPs and haplotypes was observed in all four genes in P. falciparum, and Pfdhps was the most variable gene among the four. No significant genetic differentiation could be observed in isolates from HF and RP ecotypes. Twelve novel, hitherto unreported nucleotide mutations could be observed in the Pfmdr1 and Pfdhps genes. While the Pfdhps gene presented highest haplotype diversity, the Pfcrt gene displayed the highest nucleotide diversity. When the data on all the four genes were complied, the isolates from HF ecotype were found to harbour higher average nucleotide diversity than those coming from RP ecotype. High and positive Tajima's D values were obtained for the Pfcrt and Pfdhfr genes in isolates from both the HF and RP ecotypes, with statistically significant deviation from neutrality in the RP ecotype. Different patterns of Linkage Disequilibrium (LD) among SNPs located in different drug-resistant genes were found in the isolates collected from HF and RP ecotypes. Whereas in the HF ecotype, SNPs in the Pfmdr1 and Pfdhfr were significantly associated, in the RP ecotype, SNPs located in Pfcrt were associated with Pfmdr1, Pfdhfr and Pfdhps. These findings provide a baseline understanding on how different micro eco-epidemiological settings

  7. FLUORESCENCE EMISSION SPECTRA OF MARINE AND BRACKISH-WATER ECOTYPES OF FUCUS VESICULOSUS AND FUCUS RADICANS (PHAEOPHYCEAE) REVEAL DIFFERENCES IN LIGHT-HARVESTING APPARATUS(1).

    Science.gov (United States)

    Maria Gylle, Anna; Rantamäki, Susanne; Ekelund, Nils G A; Tyystjärvi, Esa

    2011-02-01

    The Bothnian Sea in the northerly part of the Baltic Sea is a geologically recent brackish-water environment, and rapid speciation is occurring in the algal community of the Bothnian Sea. We measured low-temperature fluorescence emission spectra from the Bothnian Sea and the Norwegian Sea ecotypes of Fucus vesiculosus L., a marine macroalga widespread in the Bothnian Sea. Powdered, frozen thallus was used to obtain undistorted emission spectra. The spectra were compared with spectra measured from the newly identified species Fucus radicans Bergström et L. Kautsky, which is a close relative of F. vesiculosus and endemic to the Bothnian Sea. The spectrum of variable fluorescence was used to identify fluorescence peaks originating in PSI and PSII in this chl c-containing alga. The spectra revealed much higher PSII emission, compared to PSI emission, in the Bothnian Sea ecotype of F. vesiculosus than in F. radicans or in the Norwegian Sea ecotype of F. vesiculosus. The results suggest that more light-harvesting chl a/c proteins serve PSII in the Bothnian Sea ecotype of F. vesiculosus than in the two other algal strains. Treatment of the Bothnian Sea ecotype of F. vesiculosus in high salinity (10, 20, and 35 practical salinity units) for 1 week did not lead to spectral changes, indicating that the measured features of the Bothnian Sea F. vesiculosus are stable and not simply a direct result of exposure to low salinity.

  8. Genetic differentiation and estimation of effective population size and migration rates in two sympatric ecotypes of the marine snail Littorina saxatilis.

    Science.gov (United States)

    Fernández, J; Galindo, J; Fernández, B; Pérez-Figueroa, A; Caballero, A; Rolán-Alvarez, E

    2005-01-01

    On exposed rocky shores in Galicia (northwest Spain), a striking polymorphism exists between two ecotypes (RB and SU) of Littorina saxatilis that occupy different levels of the intertidal zone and exhibit an incomplete reproductive isolation. The setting has been suggested to represent ongoing sympatric speciation by ecological adaptation of the two ecotypes to their respective habitats. In this article we address whether or not the ecotypes have developed their own population structures in response to the rigors of their corresponding environments and life histories. We analyzed four to five allozymic loci from three surveys of the same sites, spanning a 14-year period. An experimental design including three localities with two transects per locality and three shore levels allowed studying temporal and spatial population structure and estimation of effective population sizes (N(e)), neighborhood sizes (N(n)), and migration rates (m). Genetic differentiation was significantly lower in RB populations (theta(ST) = 0.067) than in SU ones (theta(ST) = 0.124). Mean estimates of N(e), N(n), and m did not differ significantly between ecotypes, but local ecotype differences in migration between the two closest localities (larger migration rates in RB than in SU populations) could explain the pattern in population differentiation.

  9. Structure of the rare archaeal biosphere and seasonal dynamics of active ecotypes in surface coastal waters.

    Science.gov (United States)

    Hugoni, Mylène; Taib, Najwa; Debroas, Didier; Domaizon, Isabelle; Jouan Dufournel, Isabelle; Bronner, Gisèle; Salter, Ian; Agogué, Hélène; Mary, Isabelle; Galand, Pierre E

    2013-04-01

    Marine Archaea are important players among microbial plankton and significantly contribute to biogeochemical cycles, but details regarding their community structure and long-term seasonal activity and dynamics remain largely unexplored. In this study, we monitored the interannual archaeal community composition of abundant and rare biospheres in northwestern Mediterranean Sea surface waters by pyrosequencing 16S rDNA and rRNA. A detailed analysis of the rare biosphere structure showed that the rare archaeal community was composed of three distinct fractions. One contained the rare Archaea that became abundant at different times within the same ecosystem; these cells were typically not dormant, and we hypothesize that they represent a local seed bank that is specific and essential for ecosystem functioning through cycling seasonal environmental conditions. The second fraction contained cells that were uncommon in public databases and not active, consisting of aliens to the studied ecosystem and representing a nonlocal seed bank of potential colonizers. The third fraction contained Archaea that were always rare but actively growing; their affiliation and seasonal dynamics were similar to the abundant microbes and could not be considered a seed bank. We also showed that the major archaeal groups, Thaumarchaeota marine group I and Euryarchaeota group II.B in winter and Euryarchaeota group II.A in summer, contained different ecotypes with varying activities. Our findings suggest that archaeal diversity could be associated with distinct metabolisms or life strategies, and that the rare archaeal biosphere is composed of a complex assortment of organisms with distinct histories that affect their potential for growth.

  10. Salt tolerance of a wild ecotype of vetiver grass (Vetiveria zizanioides L.) in southern China.

    Science.gov (United States)

    Liu, Wan-Gou; Liu, Jin-Xiang; Yao, Mei-Ling; Ma, Qi-Fu

    2016-12-01

    Vetiver grass (Vetiveria zizanioides L.) is widely used in more than 120 countries for land management (e.g. rehabilitation of saline lands). A wild ecotype of vetiver grass was found in southern China in the 1950s, but little is known about its adaptability to saline stress. For the purpose of understanding its tolerance to salinity as well as corresponding tolerance mechanisms, in a greenhouse with natural lighting, seedlings were grown in culture solutions and subjected to a range of NaCl concentrations for 18 days. Compared to no NaCl treatment, 200 mM NaCl significantly reduced leaf water potential, leaf water content, leaf elongation rate, leaf photosynthetic rate and plant relative growth rate and increased leaf malondialdehyde (MDA) content, but the parameters showed only slight reduction at 150 mM NaCl. In addition, salinity caused an increase in the activity of antioxidant enzymes in leaves. Moreover, increasing NaCl levels significantly increased Na(+) but decreased K(+) concentrations in both roots and leaves. The leaves had higher K(+) concentrations at all NaCl levels, but lower Na(+) concentrations compared to the roots, thereby maintaining higher K(+)/Na(+) ratio in leaves. Our results showed that the salinity threshold of this wild vetiver grass is about 100 mM NaCl, i.e. highly tolerant to salt stress. This wild vetiver grass has a high ability to exclude Na(+) and retain K(+) in its leaves, which is a critical strategy for salt tolerance.

  11. Backcasting the decline of a vulnerable Great Plains reproductive ecotype: identifying threats and conservation priorities

    Science.gov (United States)

    Worthington, Thomas A.; Brewer, Shannon K.; Grabowski, Timothy B.; Mueller, Julia

    2014-01-01

    Conservation efforts for threatened or endangered species are challenging because the multi-scale factors that relate to their decline or inhibit their recovery are often unknown. To further exacerbate matters, the perceptions associated with the mechanisms of species decline are often viewed myopically rather than across the entire species range. We used over 80 years of fish presence data collected from the Great Plains and associated ecoregions of the United States, to investigate the relative influence of changing environmental factors on the historic and current truncated distributions of the Arkansas River shiner Notropis girardi. Arkansas River shiner represent a threatened reproductive ecotype considered especially well adapted to the harsh environmental extremes of the Great Plains. Historic (n = 163 records) and current (n = 47 records) species distribution models were constructed using a vector-based approach in MaxEnt by splitting the available data at a time when Arkansas River shiner dramatically declined. Discharge and stream order were significant predictors in both models; however, the shape of the relationship between the predictors and species presence varied between time periods. Drift distance (river fragment length available for ichthyoplankton downstream drift before meeting a barrier) was a more important predictor in the current model and indicated river segments 375–780 km had the highest probability of species presence. Performance for the historic and current models was high (area under the curve; AUC > 0.95); however, forecasting and backcasting to alternative time periods suggested less predictive power. Our results identify fragments that could be considered refuges for endemic plains fish species and we highlight significant environmental factors (e.g., discharge) that could be manipulated to aid recovery.

  12. Backcasting the decline of a vulnerable Great Plains reproductive ecotype: identifying threats and conservation priorities.

    Science.gov (United States)

    Worthington, Thomas A; Brewer, Shannon K; Grabowski, Timothy B; Mueller, Julia

    2014-01-01

    Conservation efforts for threatened or endangered species are challenging because the multi-scale factors that relate to their decline or inhibit their recovery are often unknown. To further exacerbate matters, the perceptions associated with the mechanisms of species decline are often viewed myopically rather than across the entire species range. We used over 80 years of fish presence data collected from the Great Plains and associated ecoregions of the United States, to investigate the relative influence of changing environmental factors on the historic and current truncated distributions of the Arkansas River shiner Notropis girardi. Arkansas River shiner represent a threatened reproductive ecotype considered especially well adapted to the harsh environmental extremes of the Great Plains. Historic (n = 163 records) and current (n = 47 records) species distribution models were constructed using a vector-based approach in MaxEnt by splitting the available data at a time when Arkansas River shiner dramatically declined. Discharge and stream order were significant predictors in both models; however, the shape of the relationship between the predictors and species presence varied between time periods. Drift distance (river fragment length available for ichthyoplankton downstream drift before meeting a barrier) was a more important predictor in the current model and indicated river segments 375-780 km had the highest probability of species presence. Performance for the historic and current models was high (area under the curve; AUC > 0.95); however, forecasting and backcasting to alternative time periods suggested less predictive power. Our results identify fragments that could be considered refuges for endemic plains fish species and we highlight significant environmental factors (e.g., discharge) that could be manipulated to aid recovery. Published 2013. This article is a U.S. Government work and is in the public domain in the U.S.A.

  13. Effects of Elevated CO2 on Biomass and Fungi Associated with Two Ecotypes of Ragweed (Ambrosia artemisiifolia L.

    Directory of Open Access Journals (Sweden)

    G. Brett Runion

    2014-09-01

    Full Text Available Herbicide resistant weed populations have developed due to the repeated application of herbicides. Elevated concentrations of atmospheric CO2 can have positive effects on weed growth, but how rising CO2 might affect herbicide resistant weeds is not known. Ragweed (Ambrosia artemisiifolia L. ecotypes known to be resistant or susceptible to glyphosate herbicide were exposed to either ambient or elevated (ambient + 200 µmol mol-1 concentrations of CO2 in open top chambers. Plants were harvested following 8 weeks of CO2 exposure; at this time, they had begun to exhibit disease symptoms including spots on leaves and stems. Elevated CO2 significantly increased top, root, and total plant biomass. Also, glyphosate resistant plants had significantly greater top, root, and total biomass than plants susceptible to the herbicide. There were no significant CO2 by ecotype interactions. Fungi from 13 genera were associated with ragweed, several of the which can be either pathogens (i.e., Alternaria, Fusarium, Rhizoctonia, aiding the decline in health of the ragweed plants, or saprophytes existing on dead plant tissues. The common foliar disease powdery mildew was significantly higher on susceptible compared with resistant ragweed. Susceptible plants also showed an increased frequency of Rhizoctonia on leaves and Alternaria on stems; however, Fusarium occurred more frequently on resistant ragweed leaves. Fungi were not affected by CO2 concentration or its interaction with ecotype. This study reports the first information on the effects of elevated CO2 on growth of herbicide resistant weeds. This is also the first study examining the impact of herbicide resistance and elevated CO2 on fungi associated with weeds. What effects herbicide resistance might have on plant diseases and how rising atmospheric CO2 might impact these effects needs to be addressed, not only with important weeds but also with crops.

  14. Effects of elevated CO2 on biomass and fungi associated with two ecotypes of ragweed (Ambrosia artemisiifolia L.).

    Science.gov (United States)

    Runion, G Brett; Prior, Stephen A; Price, Andrew J; McElroy, J Scott; Torbert, H Allen

    2014-01-01

    Herbicide resistant weed populations have developed due to the repeated application of herbicides. Elevated concentrations of atmospheric CO2 can have positive effects on weed growth, but how rising CO2 might affect herbicide resistant weeds is not known. Ragweed (Ambrosia artemisiifolia L.) ecotypes known to be resistant or susceptible to glyphosate herbicide were exposed to either ambient or elevated (ambient +200 μ mol mol(-1)) concentrations of CO2 in open top chambers. Plants were harvested following 8 weeks of CO2 exposure; at this time, they had begun to exhibit disease symptoms including spots on leaves and stems. Elevated CO2 significantly increased top, root, and total plant biomass. Also, glyphosate resistant plants had significantly greater top, root, and total biomass than plants susceptible to the herbicide. There were no significant CO2 by ecotype interactions. Fungi from 13 genera were associated with ragweed, several of which can be either pathogens (i.e., Alternaria, Fusarium, Rhizoctonia), aiding the decline in health of the ragweed plants, or saprophytes existing on dead plant tissues. The common foliar disease powdery mildew was significantly higher on susceptible compared with resistant ragweed. Susceptible plants also showed an increased frequency of Rhizoctonia on leaves and Alternaria on stems; however, Fusarium occurred more frequently on resistant ragweed leaves. Fungi were not affected by CO2 concentration or its interaction with ecotype. This study reports the first information on the effects of elevated CO2 on growth of herbicide resistant weeds. This is also the first study examining the impact of herbicide resistance and elevated CO2 on fungi associated with weeds. What effects herbicide resistance might have on plant diseases and how rising atmospheric CO2 might impact these effects needs to be addressed, not only with important weeds but also with crops.

  15. The adaptive significance of differences of root morphology, anatomy and physiology from three ecotypes of reed (Phragmites communis Trin.)

    Institute of Scientific and Technical Information of China (English)

    YuBing Liu; XinRong Li; ZhiShan Zhang; XiaoJun Li; Jin Wang

    2016-01-01

    Reeds are widely distributed in drought and high salt conditions of northwestern China. Leaf epidermal micromorpholo-gy, anatomy, chloroplast ultrastructure and physio-chemical characteristics due to long-term adaptation in the natural habitats of common reed (Phragmites communis Trin.) contrasted considerably among three different ecotypes: dune reed (DR), Gobi salt reed (GSR) and swamp reed (SR). The main objective of the present study is to determine the adapting characteristics of morphology, anatomy and physiological responses of thin roots in DR, GSR and SR. The results show that root length density was higher in SR and few root hairs were observed in DR. Cross-section anatomical features show that each ecotype has an endodermis and exodermis, while cortex thickness and proportion of root cortical aerenchyma and stele in root structure varied among the three ecotypes. The stele and xylem share a larger area in DR compared to GSR and SR. GSR has a large proportion of the cortex with radialized distribution of aerenchyma cells spacing, and the cortex has a peripheral, mechanically stiff ring in the exodermis. SEM and TEM microscope images show that GSR has a scle-renchyma ring with high lignification in the exodermis. The physio-chemical parameters show that GSR had a higher level of stress tolerance than DR. These findings indicate that developed water-absorbing tissues were largely distributed in the root structure of DR, and a main framework with supporting function spacing with aerenchyma was dominant in GSR in the long term adaptation to their natural habitats, respectively.

  16. Root responses and metal accumulation in two contrasting ecotypes of Sedum alfredii Hance under lead and zinc toxic stress.

    Science.gov (United States)

    Li, Ting-Qiang; Yang, Xiao-E; Jin, Xiao-Fen; He, Zhen-Li; Stoffella, Peter-J; Hu, Qing-Hua

    2005-01-01

    Sedum alfredii Hance has been reported to be a Zn-hyperaccumulator plant species. In this study, root morphological and physiological response of the hyperaccumulating ecotype of S. alfredii H. (HE) from the mined area and the non-hyperaccumulating ecotype of S. alfredii H. (NHE) from the agricultural area to supplied levels of Zn and Pb were investigated. The results showed that Zn concentrations in the leaves and the stems of the HE were 34 and 41 times higher, whereas lead concentrations were 1.9 and 2.4 times greater, respectively, than those of the NHE when grown at 1224 microM Zn and/or 200 microM Pb. At combined supply of 1224 microM Zn with 200 microM Pb, however, zinc concentrations in the stems and leaves of the, HE decreased, while lead concentrations in the stems increased significantly, as compared with those of single metal treatment. Lead uptake of the HE was enhanced by Zn addition. Root activity of the HE decreased by Pb treatment in the first two days, but recovered afterward and close to the control at day 10 of the treatment. However, root activity of the NHE decreased by each metal treatment, and was not recovered with the advance of treatment time. Root length, root surface area, and root volumes increased obviously due to Zn and/or Pb/Zn combined treatments for the HE, but significantly decreased due to Pb, Zn, or Pb/Zn combined treatment for the NHE. Zinc and Pb concentrations in both ecotypes of S. alfredii H. were positively correlated with root length, root surface area, and root volumes. Root exudates of the HE, especially treated with Zn, increased the extractability of Pb and Zn from the mined soil. At the Zn supply level of 1224microM, the extractability of root exudates on soil Pb was 3-12 times greater for the HE than for the NHE. These results imply that the tolerance and hyperaccumulation of the hyperaccumulating ecotype of S. alfredii H. to Zn and Pb appear to be closely related to its high adaptation of root growth, morphology

  17. Pomological features, nutritional quality, polyphenol content analysis, and antioxidant properties of domesticated and 3 wild ecotype forms of raspberries (Rubus idaeus L.).

    Science.gov (United States)

    Gülçin, Ilhami; Topal, Fevzi; Çakmakçı, Ramazan; Bilsel, Mine; Gören, Ahmet C; Erdogan, Ummugulsum

    2011-05-01

    The raspberry (Rubus idaeus L.) is an economically important berry crop that contains many phenolic compounds with potential health benefits. In this study, important pomological features, including nutrient content and antioxidant properties, of a domesticated and 3 wild (Yayla, Yavuzlar, and Yedigöl) raspberry fruits were evaluated. Also, the amount of total phenolics and flavonoids in lyophilized aqueous extracts of domesticated and wild ecotypes of raspberry fruits were calculated as gallic acid equivalents (GAEs) and quercetin equivalents (QE). The highest phenolic compounds were found in wild Yayla ecotype (26.66 ± 3.26 GAE/mg extract). Whilst, the highest flavonoids were determined in wild Yedigöl ecotype (6.09 ± 1.21 QA/mg extract). The antioxidant activity of lyophilized aqueous extracts of domesticated and wild ecotypes of raspberry fruits were investigated as trolox equivalents using different in vitro assays including DPPH(•), ABTS(•+), DMPD(•+), and O(•-)(2) radical scavenging activities, H(2)O(2) scavenging activity, ferric (Fe(3+)) and cupric ions (Cu(2+)) reducing abilities, ferrous ions (Fe(2+)) chelating activity. In addition, quantitative amounts of caffeic acid, ferulic acid, syringic acid, ellagic acid, quercetin, α-tocopherol, pyrogallol, p-hydroxybenzoic acid, vanillin, p-coumaric acid, gallic acid, and ascorbic acid in lyophilized aqueous extracts of domesticated and wild ecotypes of raspberry fruits were detected by high-performance liquid chromatography and tandem mass spectrometry (LC-MS-MS). The results clearly show that p-coumaric acid is the main phenolic acid responsible for the antioxidant and radical scavenging activity of lyophilized aqueous extracts of domesticated and wild ecotypes of raspberry fruits.

  18. Evaluation of Effect of Chemical and Organic Fertilizers on Growth Characteristics, Yield and Yield components of three Sesame Ecotypes (Sesamum indicum L.

    Directory of Open Access Journals (Sweden)

    M Goldani

    2014-07-01

    Full Text Available Using organic fertilizers is cause increase soil fertility, improving crop growth and production. For this purpose a greenhouse experiment was carried out in factorial arrangement based on a completely randomized design with three replications during 2011 year. First factor included: three sesame ecotype (MSC3, MSC6, MSC7 and second factor was 6 fertilizer treatments that included: Incorporation manure and chemical fertilizer (216 g manure and 1 gram chemical fertilizer NPK, Chemical fertilizer (2 g NPK, Vermicompost (192 g, Manure ( 228 g, Compost Sulfur granules (192 g per vase and Control (without any manure or fertilizer. Results indicated that different manure treatments had significant effect on morphological and yield components traits, as the most number and length branch per plant was obtained from incorporation manure and chemical fertilizer treatment. Appling incorporation manure and chemical fertilizer treatment had the most biomass in MSC3 ecotype that in comparison of control treatment was increased almost 73 percent. Consuming incorporation manure and chemical fertilizer treatment in MSC3 ecotype was also obtained the most capsule per plant (21.2, number seed per capsule (54.4, 100-seed weight (0.257 g and seed per plant with (1.95 g. The least seed weight per plant with 0.450 g was observed in MSC7 ecotype from application of control treatment. Response of three sesame ecotype (MSC3, MSC6, MSC7 to applied vermin-compost manure was similar; as the amount of seed weight per plant was increased more than 1 g per plant in all these ecotypes and in others fertilizer treatments was not observed this trend. There was significant positive correlation between seed weight per plant and number of capsule per plant (r=0.83**, height (r=0.68** and biomass (r=0.51**. The results showed that incorporation manure and chemical fertilizer was improved on growth and yield characteristics of sesame plant.

  19. Determination ecotypes of Populus caspica Bornm. in plain communities of Caspian forests using morphological markers of leaf and peroxidase isoenzymes

    Directory of Open Access Journals (Sweden)

    Hassan Fallah

    2011-06-01

    Full Text Available In order to determine ecotypes of Persian poplar (Populus caspica in plain communities, 40 tree individuals were selected in provinces of Guilan (Roodbar, Astane Ashrafieh and Mazandaran (Noor, Amol. Samples of two-year branches were taken in similar height and direction of tree crown to assess the quality of peroxidase activity using polyacrilamide gel electrophoresis (PAGE. Also, in numerical taxonomy study of morphology, 13 leaf morphologal traits were measured. Peroxidase banding pattern showed 11 individual bands in two zones of polyacrilamide gel. First zone included 5 polymorphism bands and the second zone represented 6 bands. The results of isoenzyme bands classification and leaf morphological traits showed high isoenzymes and morphological differentiation among populations of these species showing three separated ecotypes including Roodbar, Astaneh Ashrafieh and Noor-Amol. Also, peroxidase band pattern and leaf morphology trait between male and female individuals showed no difference within the population. The results emphasize the used of effective methods of in situ and ex situ to maintain genetic diversity of this species as an endangered and valuable in Hyrcanian forests.

  20. Out of the Pacific and back again: insights into the matrilineal history of Pacific killer whale ecotypes.

    Directory of Open Access Journals (Sweden)

    Andrew D Foote

    Full Text Available Killer whales (Orcinus orca are the most widely distributed marine mammals and have radiated to occupy a range of ecological niches. Disparate sympatric types are found in the North Atlantic, Antarctic and North Pacific oceans, however, little is known about the underlying mechanisms driving divergence. Previous phylogeographic analysis using complete mitogenomes yielded a bifurcating tree of clades corresponding to described ecotypes. However, there was low support at two nodes at which two Pacific and two Atlantic clades diverged. Here we apply further phylogenetic and coalescent analyses to partitioned mitochondrial genome sequences to better resolve the pattern of past radiations in this species. Our phylogenetic reconstructions indicate that in the North Pacific, sympatry between the maternal lineages that make up each ecotype arises from secondary contact. Both the phylogenetic reconstructions and a clinal decrease in diversity suggest a North Pacific to North Atlantic founding event, and the later return of killer whales to the North Pacific. Therefore, ecological divergence could have occurred during the allopatric phase through drift or selection and/or may have either commenced or have been consolidated upon secondary contact due to resource competition. The estimated timing of bidirectional migration between the North Pacific and North Atlantic coincided with the previous inter-glacial when the leakage of fauna from the Indo-Pacific into the Atlantic via the Agulhas current was particularly vigorous.

  1. Identification of the essential oils composition from four ecotypes of Mentha longifolia (L. Huds. growing wild in Isfahan province, Iran

    Directory of Open Access Journals (Sweden)

    REZA ABEDI

    2015-08-01

    Full Text Available Mentha longifolia L., commonly known as wild mint, belongs to family Lamiaceae. The aim of this study was to identify the chemical composition of essential oil extracted from four ecotypes of Mentha longifolia L. grown wild (Shahreza, Chadegan, Isfahan, and Falavarjan in Isfahan province (Central Iran. The essential oil was extracted by a Clevenger approach and analyzed using GC/MS. In the aerial parts of the plant were identified 26, 30, 22 and 25 compounds for Shahreza, Chadegan, Isfahan and Falavarjan ecotypes, respectively. The major constituents of the essential oil from the aerial parts of M. longifolia in Shahreza province were piperitenone oxide (26.71%, 1,8-cineole (20.72%, α-pinene (14.28%, pulegone (7.81%, sabinene (7.06% and trans-caryophyllene (4.23%. The main compositions in Chadegan province were piperitenone oxide (29.13%, 1,8-cineole (28.84%, sabinene (9.05%, pulegone (8.97% and α-pinene (6.31%. The main compositions in Isfahan province were pulegone (44.75%, 1,8-cineole (13.82%, 2-cyclohexen-1-ol, 1-methyl (8.49%, isopulegone (8.07% and menthone (4.37%. In Falavarjan province the constituents were pulegone (33.39%, 1,8-cineole (29.79%, sabinene (11.23% and isopulegone (7.28%.

  2. Stable isotopes reveal ecotypic variation of water uptake patterns in Aleppo pine

    Science.gov (United States)

    Ferrio, Juan Pedro; Lucabaugh, Devon; Chambel, Regina; Voltas, Jordi

    2014-05-01

    Aleppo pine (Pinus halepensis Mill.) has a large natural distribution range that encompasses a multitude of thermal and moisture conditions found in the Mediterranean basin. We hypothesized that due to the recurrent incidences of drought stress and high temperatures that occur at varying degrees along its distribution range, populations of Aleppo pine have undergone ecotypic differentiation in soil water uptake patterns. This study analyzed stable isotopic compositions (δ18O and δ2H) of xylem water to identify adaptive divergence associated to the pattern of soil water consumption by roots of Aleppo pine populations originating from the Mediterranean region. The results from this study show that genetic diversity in the extraction pattern of soil water can be found among populations and ecological regions of Aleppo pine under common garden conditions. However, the ability to detect such differences depended on the period of the year examined. In particular, data collection in full summer (end of July) proved to be the most adequate in revealing genetic divergence among populations, while end of spring and, to a lesser extent, end of summer, were less successful for this purpose. Both water uptake patterns (as estimated by δ18O and δ2H) and above-ground growth, exhibited significant relationships with both climatic and geographical variables. This suggests that the underlying variation among populations can be explained by certain characteristics at origin. In addition, we used a bayesian mixing model (SIAR package for R) that incorporated isotopic signatures from xylem and soil water in order to determine the predominant soil layer of water source consumption at the aforementioned periods of the growing season, where water availably ranged from lowest to highest. This allowed us to gain some understanding of Aleppo pines' differential reaction to drought, at the intraspecific level, across the fluctuating conditions of the growing season by comparing the

  3. The Amazonian Floodplains, an ecotype with challenging questions on volatile organic compound (VOC) emissions

    Science.gov (United States)

    Kesselmeier, J.

    2012-12-01

    based on short-term experiments is risky being transferred to an ecotype which is governed under natural conditions by long term flooding. Furthermore, contrasting such experiments with usually young trees (saplings or a few years old) nothing is known about the emission behavior of adult trees under field conditions.

  4. The molecular dimension of microbial species: 1. Ecological distinctions among, and homogeneity within, putative ecotypes of Synechococcus inhabiting the cyanobacterial mat of Mushroom Spring, Yellowstone National Park

    DEFF Research Database (Denmark)

    Becraft, Eric D.; Wood, Jason M.; Rusch, Douglas B.

    2015-01-01

    Based on the Stable Ecotype Model, evolution leads to the divergence of ecologically distinct populations (e.g., with different niches and/or behaviors) of ecologically interchangeable membership. In this study, pyrosequencing was used to provide deep sequence coverage of Synechococcus psaA genes...

  5. No effect of seed source on multiple aspects of ecosystem functioning during ecological restoration: cultivars compared to local ecotypes of dominant grasses

    Science.gov (United States)

    Baer, Sara G; Gibson, David J; Gustafson, Danny J; Benscoter, Allison M; Reed, Lewis K; Campbell, Ryan E; Klopf, Ryan P; Willand, Jason E; Wodika, Ben R

    2014-01-01

    Genetic principles underlie recommendations to use local seed, but a paucity of information exists on the genetic distinction and ecological consequences of using different seed sources in restorations. We established a field experiment to test whether cultivars and local ecotypes of dominant prairie grasses were genetically distinct and differentially influenced ecosystem functioning. Whole plots were assigned to cultivar and local ecotype grass sources. Three subplots within each whole plot were seeded to unique pools of subordinate species. The cultivar of the increasingly dominant grass, Sorghastrum nutans, was genetically different than the local ecotype, but genetic diversity was similar between the two sources. There were no differences in aboveground net primary production, soil carbon accrual, and net nitrogen mineralization rate in soil between the grass sources. Comparable productivity of the grass sources among the species pools for four years shows functional equivalence in terms of biomass production. Subordinate species comprised over half the aboveground productivity, which may have diluted the potential for documented trait differences between the grass sources to influence ecosystem processes. Regionally developed cultivars may be a suitable alternative to local ecotypes for restoration in fragmented landscapes with limited gene flow between natural and restored prairie and negligible recruitment by seed. PMID:24567751

  6. Characterization of the uranium (VI) complexes formed by the cells of three A. ferrooxidans eco-types using time-resolved laser-induced fluorescence spectroscopy (TRLFS)

    Energy Technology Data Exchange (ETDEWEB)

    Merroun, M.; Geipel, G.; Selenska-Pobell, S.

    2002-05-01

    TRLFS was used to study the properties of the uranium complexes formed by the cells of the three recently described eco-types of A. ferrooxidans /1/. The results demonstrate that the lifetimes of the complexes are type-specific and are increasing in the same order as the capability of the bacterial strains to accumulate uranium. (orig.)

  7. PHYTOTOXICITY AND FIELD EFFICACY OF EXSEROHILUM LONGIROSTRA JC/MIN THE CONTROL OF BARNYARDGRASS ECOTYPES (ECHINOCHLOA CRUS-GALLI VAR. CRUS-GALLI(L. BEAUV

    Directory of Open Access Journals (Sweden)

    SUHAIMI NAPIS

    2005-01-01

    Full Text Available Five selected ecotypes of bamyardgrass (Echinochloa crus-galli var. crus-gatti from several rice growing areas in Malaysia and Indonesia were tested for their susceptibility to the potentia l bioherbicide (Exserohilum longirostratum. Bamyardgrass seedlings at the 2-3-lcaf stage were treated with 2.5xl07 conidia/ml from E. longirostratum at different application frequencies (single, double and triple. In addition, aqueous extract assays were ev aluated for the presence of a phytotoxic compound responsible for the virulence of the bioherbicide. Results of the study showed that disease severity significantly increased 20 days after treatment and resulted in mortality of the seedlin gs. Ecotypes from Perak and Lampung were most susceptible to the bioherbicide upon triple applications. Percentage dry weight reductions were 86.34 and 83.14%, respectively. Other ecotypes (Melaka, Banten and South Sulawesi were observed to have a relatively similar response. Moreover, aqueous extracts of E. longirostratum increased mortality up to 92.50% of bamyardgrass seedlings. These findings suggest that regular (double and triple applications of E. longirostratum at a concentration of 2.5xl07 conidia/ml significantly increased mortality among bamyardgrass ecotypes. Mortality of the seedlings was attributed to the presence of a secondary phytotoxic metabolite.

  8. Root and shoot transcriptome analysis of two ecotypes of Noccaea caerulescens uncovers the role of NcNramp1 in Cd hyperaccumulation.

    Science.gov (United States)

    Milner, Matthew J; Mitani-Ueno, Namiki; Yamaji, Naoki; Yokosho, Kengo; Craft, Eric; Fei, Zhangjun; Ebbs, Stephen; Clemencia Zambrano, M; Ma, Jian Feng; Kochian, Leon V

    2014-05-01

    The Zn/Cd hyperaccumulator, Noccaea caerulescens, has been studied extensively for its ability to accumulate high levels of Zn and Cd in its leaves. Previous studies have indicated that the Zn and Cd hyperaccumulation trait exhibited by this species involves different transport and tolerance mechanisms. It has also been well documented that certain ecotypes of N. caerulescens are much better Cd hyperaccumulators than others. However, there does not seem to be much ecotypic variation for Zn hyperaccumulation in N. caerulescens. In this study we employed a comparative transcriptomics approach to look at root and shoot gene expression in Ganges and Prayon plants in response to Cd stress to identify transporter genes that were more highly expressed in either the roots or shoots of the superior Cd accumulator, Ganges. Comparison of the transcriptomes from the two ecotypes of Noccaea caerulescens identified a number of genes that encoded metal transporters that were more highly expressed in the Ganges ecotype in response to Cd stress. Characterization of one of these transporters, NcNramp1, showed that it is involved in the influx of Cd across the endodermal plasma membrane and thus may play a key role in Cd flux into the stele and root-to-shoot Cd transport. NcNramp1 may be one of the main transporters involved in Cd hyperaccumulation in N. caerulescens and copy number variation appears to be the main reason for high NcNramp1 gene expression underlying the increased Cd accumulation in the Ganges ecotype. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  9. The molecular dimension of microbial species: 1. Ecological distinctions among, and homogeneity within, putative ecotypes of Synechococcus inhabiting the cyanobacterial mat of Mushroom Spring, Yellowstone National Park.

    Science.gov (United States)

    Becraft, Eric D; Wood, Jason M; Rusch, Douglas B; Kühl, Michael; Jensen, Sheila I; Bryant, Donald A; Roberts, David W; Cohan, Frederick M; Ward, David M

    2015-01-01

    Based on the Stable Ecotype Model, evolution leads to the divergence of ecologically distinct populations (e.g., with different niches and/or behaviors) of ecologically interchangeable membership. In this study, pyrosequencing was used to provide deep sequence coverage of Synechococcus psaA genes and transcripts over a large number of habitat types in the Mushroom Spring microbial mat. Putative ecological species [putative ecotypes (PEs)], which were predicted by an evolutionary simulation based on the Stable Ecotype Model (Ecotype Simulation), exhibited distinct distributions relative to temperature-defined positions in the effluent channel and vertical position in the upper 1 mm-thick mat layer. Importantly, in most cases variants predicted to belong to the same PE formed unique clusters relative to temperature and depth in the mat in canonical correspondence analysis, supporting the hypothesis that while the PEs are ecologically distinct, the members of each ecotype are ecologically homogeneous. PEs responded differently to experimental perturbations of temperature and light, but the genetic variation within each PE was maintained as the relative abundances of PEs changed, further indicating that each population responded as a set of ecologically interchangeable individuals. Compared to PEs that predominate deeper within the mat photic zone, the timing of transcript abundances for selected genes differed for PEs that predominate in microenvironments closer to upper surface of the mat with spatiotemporal differences in light and O2 concentration. All of these findings are consistent with the hypotheses that Synechococcus species in hot spring mats are sets of ecologically interchangeable individuals that are differently adapted, that these adaptations control their distributions, and that the resulting distributions constrain the activities of the species in space and time.

  10. Lead Induced Changes in the Growth and Antioxidant Metabolism of the Lead Accumulating and Non-accumulating Ecotypes of Sedum alfredii

    Institute of Scientific and Technical Information of China (English)

    Dan Liu; Ting-Qiang Li; Xiao-Fen Jin; Xiao-E Yang; Ejazul Islam; Qaisar Mahmood

    2008-01-01

    The phytotoxicity and antioxidative adaptations of lead (Pb) accumulating ecotype (AE) and non-accumulating ecotype (NAE) of Sedum alfredii Hance were investigated under different Pb treatments involving 0, 0.02 mmol/L Pb, 0.1 mmol/L Pb and 0.1 mmol/L Pb/0.1 mmol/L ethylenediaminetetraacetic acid (EDTA) for 6days. With the Increasing Pb level, the Pb concentration in the shoots of AE plants enhanced accordingly, and EDTA supply helped 51% of Pb translocation to shoots of AE compared with those treated with 0.1 mmol/L Pb alone. Moreover, the presence of EDTA alleviated Pb phytotoxicity through changes in plant biomass, root morphology and chlorophyll contents. Lead toxicity Induced hydrogen peroxide (H2O2) accumulation and lipid peroxidation in both ecotypes of S. alfredii. The activities of superoxide dismutase (SOD), guaiacol peroxidase (G-POD), ascorbate peroxidase, and dehydroascorbate reductase elevated in both leaves and roots of AE as well as in leaves of NAE with the increasing Pb levels, but SOD and G-POD declined in roots of NAE. Enhancement in glutathione reductase activity was only detected in roots of NAE while a depression in catalase activity was recorded in the leaves of NAE. A significant enhancement in glutathione and ascorbic acid (AsA) levels occurred In both ecotypes exposed to Pb and Pb/EDTA treatment compared with the control, however, the differences between these two treatments were insignificant. The dehydroascorbate (DHA) contents in roots of both ecotypes were 1.41 to 11.22-fold higher than those in leaves, whereas the ratios of AsA to DHA (1.38 to 6.84) in leaves altering more to the reduced AsA form were much higher than those in roots. These results suggested that antioxidative enzymes and antioxidants play an important role in counteracting Pb stress in S. alfredii.

  11. Distribution of Prochlorococcus Ecotypes in the Red Sea Basin Based on Analyses of rpoC1 Sequences

    KAUST Repository

    Shibl, Ahmed A.

    2016-06-25

    The marine picocyanobacteria Prochlorococcus represent a significant fraction of the global pelagic bacterioplankton community. Specifically, in the surface waters of the Red Sea, they account for around 91% of the phylum Cyanobacteria. Previous work suggested a widespread presence of high-light (HL)-adapted ecotypes in the Red Sea with the occurrence of low-light (LL)-adapted ecotypes at intermediate depths in the water column. To obtain a more comprehensive dataset over a wider biogeographical scope, we used a 454-pyrosequencing approach to analyze the diversity of the Prochlorococcus rpoC1 gene from a total of 113 samples at various depths (up to 500 m) from 45 stations spanning the Red Sea basin from north to south. In addition, we analyzed 45 metagenomes from eight stations using hidden Markov models based on a set of reference Prochlorococcus genomes to (1) estimate the relative abundance of Prochlorococcus based on 16S rRNA gene sequences, and (2) identify and classify rpoC1 sequences as an assessment of the community structure of Prochlorococcus in the northern, central and southern regions of the basin without amplification bias. Analyses of metagenomic data indicated that Prochlorococcus occurs at a relative abundance of around 9% in samples from surface waters (25, 50, 75 m), 3% in intermediate waters (100 m) and around 0.5% in deep-water samples (200–500 m). Results based on rpoC1 sequences using both methods showed that HL II cells dominate surface waters and were also present in deep-water samples. Prochlorococcus communities in intermediate waters (100 m) showed a higher diversity and co-occurrence of low-light and high-light ecotypes. Prochlorococcus communities at each depth range (surface, intermediate, deep sea) did not change significantly over the sampled transects spanning most of the Saudi waters in the Red Sea. Statistical analyses of rpoC1 sequences from metagenomes indicated that the vertical distribution of Prochlorococcus in the water

  12. Different NaCl-Induced Calcium Signatures in the Arabidopsis thaliana Ecotypes Col-0 and C24

    KAUST Repository

    Schmöckel, Sandra M.

    2015-02-27

    A common feature of stress signalling pathways are alterations in the concentration of cytosolic free calcium ([Ca2+]cyt), which allow the specific and rapid transmission of stress signals through a plant after exposure to a stress, such as salinity. Here, we used an aequorin based bioluminescence assay to compare the NaCl-induced changes in [Ca2+]cyt of the Arabidopsis ecotypes Col-0 and C24. We show that C24 lacks the NaCl specific component of the [Ca2+]cyt signature compared to Col-0. This phenotypic variation could be exploited as a screening methodology for the identification of yet unknown components in the early stages of the salt signalling pathway.

  13. Different NaCl-induced calcium signatures in the Arabidopsis thaliana ecotypes Col-0 and C24.

    Science.gov (United States)

    Schmöckel, Sandra M; Garcia, Alexandre F; Berger, Bettina; Tester, Mark; Webb, Alex A R; Roy, Stuart J

    2015-01-01

    A common feature of stress signalling pathways are alterations in the concentration of cytosolic free calcium ([Ca2+]cyt), which allow the specific and rapid transmission of stress signals through a plant after exposure to a stress, such as salinity. Here, we used an aequorin based bioluminescence assay to compare the NaCl-induced changes in [Ca2+]cyt of the Arabidopsis ecotypes Col-0 and C24. We show that C24 lacks the NaCl specific component of the [Ca2+]cyt signature compared to Col-0. This phenotypic variation could be exploited as a screening methodology for the identification of yet unknown components in the early stages of the salt signalling pathway.

  14. A compatible interaction of Alternaria brassicicola with Arabidopsis thaliana ecotype DiG: evidence for a specific transcriptional signature

    Directory of Open Access Journals (Sweden)

    Gepstein Shimon

    2009-03-01

    Full Text Available Abstract Background The interaction of Arabidopsis with Alternaria brassicicola provides a model for disease caused by necrotrophs, but a drawback has been the lack of a compatible pathosystem. Infection of most ecotypes, including the widely-studied line Col-0, with this pathogen generally leads to a lesion that does not expand beyond the inoculated area. This study examines an ecotype, Dijon G (DiG, which is considered sensitive to A. brassicicola. Results We show that the interaction has the characteristics of a compatible one, with expanding rather than limited lesions. To ask whether DiG is merely more sensitive to the pathogen or, rather, interacts in distinct manner, we identified genes whose regulation differs between Col-0 and DiG challenged with A. brassicicola. Suppression subtractive hybridization was used to identify differentially expressed genes, and their expression was verified using semi-quantitative PCR. We also tested a set of known defense-related genes for differential regulation in the two plant-pathogen interactions. Several known pathogenesis-related (PR genes are up-regulated in both interactions. PR1, and a monooxygenase gene identified in this study, MO1, are preferentially up-regulated in the compatible interaction. In contrast, GLIP1, which encodes a secreted lipase, and DIOX1, a pathogen-response related dioxygenase, are preferentially up-regulated in the incompatible interaction. Conclusion The results show that DiG is not only more susceptible, but demonstrate that its interaction with A. brassicicola has a specific transcriptional signature.

  15. Imaging with the fluorogenic dye Basic Fuchsin reveals subcellular patterning and ecotype variation of lignification in Brachypodium distachyon

    Science.gov (United States)

    Kapp, Nikki; Barnes, William J.; Richard, Tom L.; Anderson, Charles T.

    2015-01-01

    Lignin is a complex polyphenolic heteropolymer that is abundant in the secondary cell walls of plants and functions in growth and defence. It is also a major barrier to the deconstruction of plant biomass for bioenergy production, but the spatiotemporal details of how lignin is deposited in actively lignifying tissues and the precise relationships between wall lignification in different cell types and developmental events, such as flowering, are incompletely understood. Here, the lignin-detecting fluorogenic dye, Basic Fuchsin, was adapted to enable comparative fluorescence-based imaging of lignin in the basal internodes of three Brachypodium distachyon ecotypes that display divergent flowering times. It was found that the extent and intensity of Basic Fuchsin fluorescence increase over time in the Bd21-3 ecotype, that Basic Fuchsin staining is more widespread and intense in 4-week-old Bd21-3 and Adi-10 basal internodes than in Bd1-1 internodes, and that Basic Fuchsin staining reveals subcellular patterns of lignin in vascular and interfascicular fibre cell walls. Basic Fuchsin fluorescence did not correlate with lignin quantification by acetyl bromide analysis, indicating that whole-plant and subcellular lignin analyses provide distinct information about the extent and patterns of lignification in B. distachyon. Finally, it was found that flowering time correlated with a transient increase in total lignin, but did not correlate strongly with the patterning of stem lignification, suggesting that additional developmental pathways might regulate secondary wall formation in grasses. This study provides a new comparative tool for imaging lignin in plants and helps inform our views of how lignification proceeds in grasses. PMID:25922482

  16. Adaptation to flooding in upland and lowland ecotypes of Cyperus rotundus, a troublesome sedge weed of rice: tuber morphology and carbohydrate metabolism

    Science.gov (United States)

    Peña-Fronteras, Jennifer T.; Villalobos, Mizpah C.; Baltazar, Aurora M.; Merca, Florinia E.; Ismail, Abdelbagi M.; Johnson, David E.

    2009-01-01

    Background and aims In recent years, Cyperus rotundus has become a problem weed in lowland rice (Oryza sativa) grown in rotation with vegetables in the Philippines. As the growth of C. rotundus is commonly suppressed by prolonged flooding, the ability of the weed to grow vigorously in flooded as well as upland conditions suggests that adapted ecotypes occur in these rotations. Studies were conducted to elucidate the mechanisms that permit C. rotundus to tolerate flooded soil conditions. Methods Upland and lowland ecotypes of C. rotundus were compared in terms of growth habit, carbohydrate reserves and metabolism, and activities of enzymes involved in alcoholic fermentation – alcohol dehydrogenase (ADH) and pyruvate decarboxylase (PDC). Key Results The lowland ecotype has much larger tubers than the upland ecotype. Prior to germination, the amylase activity and total non-structural carbohydrate content in the form of soluble sugars were greater in the tubers of lowland plants than in those of upland C. rotundus. At 24 h after germination in hypoxic conditions, PDC and ADH activities in the lowland plants increased, before decreasing at 48 h following germination. In contrast, ADH and PDC activities in the upland plants increased from 24 to 48 h after germination. Conclusions Tolerance of lowland C. rotundus of flooding may be attributed to large carbohydrate content and amylase activity, and the ability to maintain high levels of soluble sugars in the tubers during germination and early growth. This is coupled with the modulation of ADH and PDC activities during germination, possibly to control the use of carbohydrate reserves and sustain substrate supply in order to avoid starvation and death of seedlings with prolonged flooding. PMID:18515404

  17. Evaluation of Effect of Chemical and Organic Fertilizers on Growth Characteristics, Yield and Yield components of three Sesame Ecotypes (Sesamum indicum L.)

    OpenAIRE

    M Goldani; Fazel Fazeli Kakhki

    2014-01-01

    Using organic fertilizers is cause increase soil fertility, improving crop growth and production. For this purpose a greenhouse experiment was carried out in factorial arrangement based on a completely randomized design with three replications during 2011 year. First factor included: three sesame ecotype (MSC3, MSC6, MSC7) and second factor was 6 fertilizer treatments that included: Incorporation manure and chemical fertilizer (216 g manure and 1 gram chemical fertilizer NPK), Chemical fertil...

  18. PHYTOTOXICITY AND FIELD EFFICACY OF EXSEROHILUM LONGIROSTRA JC/MIN THE CONTROL OF BARNYARDGRASS ECOTYPES (ECHINOCHLOA CRUS-GALLI VAR. CRUS-GALLI(L.) BEAUV)

    OpenAIRE

    SUHAIMI NAPIS; ARIFIN TASRIF; JUGAH KADIR; ABDUL SHUKOR JURAIMI; SOETIKNO SLAMET SASTROUTOMO

    2005-01-01

    Five selected ecotypes of bamyardgrass (Echinochloa crus-galli var. crus-gatti) from several rice growing areas in Malaysia and Indonesia were tested for their susceptibility to the potentia l bioherbicide (Exserohilum longirostratum). Bamyardgrass seedlings at the 2-3-lcaf stage were treated with 2.5xl07 conidia/ml from E. longirostratum at different application frequencies (single, double and triple). In addition, aqueous extract assays were ev aluated for the presence of a phytotoxic c...

  19. RAPD-PCR and real-time PCR HRM based genetic variation evaluations of Urtica dioica parts, ecotypes and evaluations of morphotypes in Turkey.

    Science.gov (United States)

    Uzonur, Irem; Akdeniz, Gamze; Katmer, Zeynep; Ersoy, Seyda Karaman

    2013-01-01

    Urtica dioica is an ethnobotanically and medicinally important Complementary and Alternative Medicine (CAM) plant worldwide and in Turkey; 90 % of herbal CAM applications depend on it in Turkey. It has a wide range of habitats in nearly all continents. It is found in all three phytogeographical regions in Turkey (Euro-Siberian, Irano-Turanian, Mediterranean) with high adaptivity to heterogeneous geographies such as climate, soil types and altitudes. This fact in relation to the assessment of chemical constituents of the plant and combining with further genetic and morphological variation data can assist and enhance the works for the utility and reliability of CAM applications in effect and activity of this plant species. In this work we have made some preliminary experiments with novel approaches to reveal the ecotypes and genetic variation of mighty ecotypes of Urtica dioica from different phytogeographical regions of Turkey (Euro-Siberian and Mediterranean). The ecotypes have heterogeneity in both its parts (leaf, stem, root) as revealed by Random Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR) using random primers and High-resolution Melt (HRM) analysis using Urtica dioica specific primers and universal chloroplast DNA (cpDNA) primers and morphological traits such as phenolic contents and antioxidant capacities of plants' leaf infusions as used in medicinal applications in Turkey. This work will contribute a lot for the development of molecular markers to detect the genetic variation and heterogeneity of Urtica dioica to further relate with expected phenotypes that are most useful and relevant in CAM applications.

  20. A Comparative Study of Growth Performance and Feed Efficiency in Dominant Black Strain, Fulani Ecotype Chicken and Progeny from their Reciprocal Crosses

    Directory of Open Access Journals (Sweden)

    Sola-Ojo, F. E.

    2012-06-01

    Full Text Available A study of the relative performance of a local chicken (Fulani Ecotype or FExFE, an exotic chicken (Dominant Black or DBxDB, and their reciprocal crosses (DBxFE and FExDB was undertaken. A total of three hundred and thirty (330 chickens comprising 100 DBxDB, 80 DBxFE, 80 FExDB and 70 FExFE were studied. All animals were raised from day old to 21 weeks age contemporaneously under identical housing, feeding and management procedures during which growth parameters were measured. Significant (p DBxFE 1346.80±3.05 > DBxDB 1314.40±3.61 over the 21 week experimental period. FExFE had significantly (p FExFE 67.50±0.02 over the same period. Low mortality (≤ 2% occurred across genotypes with FExFE having the least mortality. The results indicated that reciprocal crossing of pure local Fulani Ecotype with exotic Dominant Black strain produces chickens with indistinguishable Feed Efficiency from the highly improved Dominant Black, and superior to the pure Fulani. Cross breeding of the type reported here may therefore serve as a tool for improving efficiency of Fulani Ecotype local poultry whilst retaining elements of their valued characteristics which include meat value. Further studies will evaluate the hybrids (F1 of FE and DB for retention of desirable characteristics of local breeds.

  1. Seed longevity of red rice ecotypes buried in soil Longevidade de sementes de arroz-vermelho enterradas no solo

    Directory of Open Access Journals (Sweden)

    J.A. Noldin

    2006-12-01

    Full Text Available Red rice is a troublesome weed in irrigated rice production and is spread through contaminated commercial rice seed and machinery. Seed dormancy is a major trait for red rice. Studies were carried out at two locations to determine red rice seed longevity in the soil of several ecotypes from four US states. Five months after burial near Beaumont, Texas only three ecotypes had viable seed (O arroz-vermelho constitui-se na principal planta daninha infestante de lavouras de arroz irrigado e a sua disseminação ocorre, principalmente, pelo uso de sementes comerciais contaminadas e equipamentos agrícolas. A ocorrência de dormência nas sementes é uma das principais características que dificultam o controle do arroz-vermelho em lavouras. O objetivo deste trabalho foi estimar a longevidade no solo de ecótipos de arroz-vermelho provenientes de diferentes áreas de produção de arroz nos Estados Unidos. O estudo foi conduzido em dois locais: Beaumont e College Station, no estado do Texas (TX. Para sementes enterradas a 5 cm de profundidade em Beaumont, apenas três ecótipos apresentaram sementes viáveis (<1%. No entanto, quando as sementes foram enterradas em maior profundidade (25 cm, nove ecótipos tinham sementes viáveis após 2 anos. Trinta e seis meses após o enterrio, cinco ecótipos apresentavam sementes com alguma viabilidade, mas todos inferiores a 1%. Sementes de arroz-vermelho produzidas e enterradas em College Station na profundidade de 12 cm, um dia após a colheita, apresentaram maior longevidade que aquelas mantidas na superfície do solo. Após 17 meses, um dos ecótipos de arroz-preto (TX 4, enterrado a 12 cm, foi o que apresentou maior percentual de viabilidade (2%. Nos dois experimentos, observou-se que os cultivares comerciais, Lemont e Mars, não apresentaram sementes viáveis após cinco meses, independentemente da localização no solo. Os resultados deste estudo sugerem que em áreas com arroz-vermelho deve-se evitar o

  2. Metabolic profiling of root exudates from two ecotypes of Sedum alfredii treated with Pb based on GC-MS

    Science.gov (United States)

    Luo, Qing; Wang, Shiyu; Sun, Li-Na; Wang, Hui

    2017-01-01

    Phytoremediation is an effective method to remediate Pb-contaminated soils and root exudates play an important role in this process. Based on gas chromatography-mass spectrometry (GC-MS) and metabolomics method, this study focuses on the comparative metabolic profiling analysis of root exudates from the Pb-accumulating and non-accumulating ecotypes of Sedum alfredii treated with 0 and 50 μmol/L Pb. The results obtained show that plant type and Pb stress can significantly change the concentrations and species of root exudates, and fifteen compounds were identified and assumed to be potential biomarkers. Leaching experiments showed that l-alanine, l-proline and oxalic acid have a good effect to activate Pb in soil, glyceric acid and 2-hydroxyacetic acid have a general effect to activate Pb in soil. 4-Methylphenol and 2-methoxyphenol might be able to activate Pb in soil, glycerol and diethyleneglycol might be able to stabilize Pb in soil, but these activation effect and stabilization effect were all not obvious.

  3. Non-destructive flavour evaluation of red onion (Allium cepa L.) ecotypes: an electronic-nose-based approach.

    Science.gov (United States)

    Russo, Mariateresa; di Sanzo, Rosa; Cefaly, Vittoria; Carabetta, Sonia; Serra, Demetrio; Fuda, Salvatore

    2013-11-15

    This work reports preliminary results on the potential of a metal oxide sensor (MOS)-based electronic nose, as a non-destructive method to discriminate three "Tropea Red Onion" PGI ecotypes (TrT, TrMC and TrA) from each other and the common red onion (RO), which is usually used to counterfeit. The signals from the sensor array were processed using a canonical discriminant function analysis (DFA) pattern recognition technique. The DFA on onion samples showed a clear separation among the four onion groups with an overall correct classification rate (CR) of 97.5%. Onion flavour is closely linked to pungency and thus to the pyruvic acid content. The e-nose analysis results are in good agreement with pyruvic acid analysis. This work demonstrated that artificial olfactory systems have potential for use as an innovative, rapid and specific non-destructive technique, and may provide a method to protect food products against counterfeiting. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Species Diversity, Abundance, and Host Preferences of Mosquitoes (Diptera: Culicidae) in Two Different Ecotypes of Madagascar With Recent RVFV Transmission.

    Science.gov (United States)

    Jean Jose Nepomichene, Thiery Nirina; Elissa, Nohal; Cardinale, Eric; Boyer, Sebastien

    2015-09-01

    Mosquito diversity and abundance were examined in six Madagascan villages in either arid (Toliary II district) or humid (Mampikony district) ecotypes, each with a history of Rift Valley fever virus transmission. Centers for Disease Control and Prevention light traps without CO2 (LT) placed near ruminant parks and animal-baited net trap (NT) baited with either zebu or sheep/goat were used to sample mosquitoes, on two occasions between March 2011 and October 2011. Culex tritaeniorhynchus (Giles) was the most abundant species, followed by Culex antennatus (Becker) and Anopheles squamosus/cydippis (Theobald/de Meillon). These three species comprised more than half of all mosquitoes collected. The NT captured more mosquitoes in diversity and in abundance than the LT, and also caught more individuals of each species, except for An. squamosus/cydippis. Highest diversity and abundance were observed in the humid and warm district of Mampikony. No host preference was highlighted, except for Cx. tritaeniorhynchus presenting a blood preference for zebu baits. The description of species diversity, abundance, and host preference described herein can inform the development of control measures to reduce the risk of mosquito-borne diseases in Madagascar.

  5. Otolith morphology and hearing abilities in cave- and surface-dwelling ecotypes of the Atlantic molly, Poecilia mexicana (Teleostei: Poeciliidae).

    Science.gov (United States)

    Schulz-Mirbach, Tanja; Ladich, Friedrich; Riesch, Rüdiger; Plath, Martin

    2010-08-01

    Cave fish have rarely been investigated with regard to their inner ear morphology, hearing abilities, and acoustic communication. Based on a previous study that revealed morphological differences in the saccular otolith between a cave and two surface populations of Poecilia mexicana, we checked for additional differences in utricular and lagenar otoliths and tested whether different populations have similar hearing sensitivities. We found pronounced differences in the shape of all three otoliths. Otoliths of the saccule and lagena from cave fish differed from those of surface fish in the features of the face oriented towards the sensory epithelium. In addition, otoliths of the utricle and lagena were significantly heavier in cave fish. Auditory sensitivities were measured between 100 and 1500Hz, utilizing the auditory evoked potential recording technique. We found similar hearing abilities in cave and surface fish, with greatest sensitivity between 200 and 300Hz. An acoustic survey revealed that neither ecotype produced species-specific sounds. Our data indicate that cave dwelling altered the otolith morphology in Atlantic mollies, probably due to metabolic differences. Different otolith morphology, however, did not affect general auditory sensitivity or acoustic behavior.

  6. Comparative proteomics reveals that a saxitoxin-producing and a nontoxic strain of Anabaena circinalis are two different ecotypes.

    Science.gov (United States)

    D'Agostino, Paul M; Song, Xiaomin; Neilan, Brett A; Moffitt, Michelle C

    2014-03-01

    In Australia, saxitoxin production is restricted to the cyanobacterial species Anabaena circinalis and is strain-dependent. We aimed to characterize a saxitoxin-producing and nontoxic strain of A. circinalis at the proteomic level using iTRAQ. Seven proteins putatively involved in saxitoxin biosynthesis were identified within our iTRAQ experiment for the first time. The proteomic profile of the toxic A. circinalis was significantly different from the nontoxic strain, indicating that each is likely to inhabit a unique ecological niche. Under control growth conditions, the saxitoxin-producing A. circinalis displayed a higher abundance of photosynthetic, carbon fixation and nitrogen metabolic proteins. Differential abundance of these proteins suggests a higher intracellular C:N ratio and a higher concentration of intracellular 2-oxoglutarate in our toxic strain compared with the nontoxic strain. This may be a novel site for posttranslational regulation because saxitoxin biosynthesis putatively requires a 2-oxoglutarate-dependent dioxygenase. The nontoxic A. circinalis was more abundant in proteins, indicating cellular stress. Overall, our study has provided the first insight into fundamental differences between a toxic and nontoxic strain of A. circinalis, indicating that they are distinct ecotypes.

  7. Cold-acclimation limits low temperature induced photoinhibition by promoting a higher photochemical quantum yield and a more effective PSII restoration in darkness in the Antarctic rather than the Andean ecotype of Colobanthus quitensis Kunt Bartl (Cariophyllaceae

    Directory of Open Access Journals (Sweden)

    Bascuñán-Godoy Luisa

    2012-07-01

    Full Text Available Abstract Background Ecotypes of Colobanthus quitensis Kunt Bartl (Cariophyllaceae from Andes Mountains and Maritime Antarctic grow under contrasting photoinhibitory conditions, reaching differential cold tolerance upon cold acclimation. Photoinhibition depends on the extent of photodamage and recovery capability. We propose that cold acclimation increases resistance to low-temperature-induced photoinhibition, limiting photodamage and promoting recovery under cold. Therefore, the Antarctic ecotype (cold hardiest should be less photoinhibited and have better recovery from low-temperature-induced photoinhibition than the Andean ecotype. Both ecotypes were exposed to cold induced photoinhibitory treatment (PhT. Photoinhibition and recovery of photosystem II (PSII was followed by fluorescence, CO2 exchange, and immunoblotting analyses. Results The same reduction (25% in maximum PSII efficiency (Fv/Fm was observed in both cold-acclimated (CA and non-acclimated (NA plants under PhT. A full recovery was observed in CA plants of both ecotypes under dark conditions, but CA Antarctic plants recover faster than the Andean ecotype. Under PhT, CA plants maintain their quantum yield of PSII, while NA plants reduced it strongly (50% and 73% for Andean and Antarctic plants respectively. Cold acclimation induced the maintenance of PsaA and Cyt b6/f and reduced a 41% the excitation pressure in Antarctic plants, exhibiting the lowest level under PhT. xCold acclimation decreased significantly NPQs in both ecotypes, and reduced chlorophylls and D1 degradation in Andean plants under PhT. NA and CA plants were able to fully restore their normal photosynthesis, while CA Antarctic plants reached 50% higher photosynthetic rates after recovery, which was associated to electron fluxes maintenance under photoinhibitory conditions. Conclusions Cold acclimation has a greater importance on the recovery process than on limiting photodamage. Cold acclimation determined the

  8. Cold-acclimation limits low temperature induced photoinhibition by promoting a higher photochemical quantum yield and a more effective PSII restoration in darkness in the Antarctic rather than the Andean ecotype of Colobanthus quitensis Kunt Bartl (Cariophyllaceae).

    Science.gov (United States)

    Bascuñán-Godoy, Luisa; Sanhueza, Carolina; Cuba, Marely; Zuñiga, Gustavo E; Corcuera, Luis J; Bravo, León A

    2012-07-24

    Ecotypes of Colobanthus quitensis Kunt Bartl (Cariophyllaceae) from Andes Mountains and Maritime Antarctic grow under contrasting photoinhibitory conditions, reaching differential cold tolerance upon cold acclimation. Photoinhibition depends on the extent of photodamage and recovery capability. We propose that cold acclimation increases resistance to low-temperature-induced photoinhibition, limiting photodamage and promoting recovery under cold. Therefore, the Antarctic ecotype (cold hardiest) should be less photoinhibited and have better recovery from low-temperature-induced photoinhibition than the Andean ecotype. Both ecotypes were exposed to cold induced photoinhibitory treatment (PhT). Photoinhibition and recovery of photosystem II (PSII) was followed by fluorescence, CO2 exchange, and immunoblotting analyses. The same reduction (25%) in maximum PSII efficiency (Fv/Fm) was observed in both cold-acclimated (CA) and non-acclimated (NA) plants under PhT. A full recovery was observed in CA plants of both ecotypes under dark conditions, but CA Antarctic plants recover faster than the Andean ecotype.Under PhT, CA plants maintain their quantum yield of PSII, while NA plants reduced it strongly (50% and 73% for Andean and Antarctic plants respectively). Cold acclimation induced the maintenance of PsaA and Cyt b6/f and reduced a 41% the excitation pressure in Antarctic plants, exhibiting the lowest level under PhT. xCold acclimation decreased significantly NPQs in both ecotypes, and reduced chlorophylls and D1 degradation in Andean plants under PhT.NA and CA plants were able to fully restore their normal photosynthesis, while CA Antarctic plants reached 50% higher photosynthetic rates after recovery, which was associated to electron fluxes maintenance under photoinhibitory conditions. Cold acclimation has a greater importance on the recovery process than on limiting photodamage. Cold acclimation determined the kinetic and extent of recovery process under darkness in

  9. The Effect of Irrigation Cut-off in Flowering Stage and Foliar Application of Spermidine on Essential Oil Quantity and Quality of Three Ecotypes of Cumin

    Directory of Open Access Journals (Sweden)

    Sarah Bakhtari

    2017-03-01

    Full Text Available Introduction Cumin (Cuminum cyminum L. is an annual plant that commonly cultivated in arid and semiarid regions of Iran. The crop has a wide range of uses including medicinal, cosmetic and food industry. Cumin occupies about 26% of total area devoted to medicinal plants in Iran. However, cumin is seriously affected by the Fusarium wilt and blight diseases. The diseases usually increase under warm and wet conditions. Control of the diseases incidence is a crucial factor for cumin production. Limited control of the diseases is provided by seed pre-sowing with certain fungicides such as benlate. Soil fumigation with methyle bromide can provide a control measure against the disease but may be limited application value for large scale production systems in the open field. In addition, methyle bromide is considered an ozone-depleting compound and has potential risk on the living environment and human health. Considering the environmental limitations of chemical fungicides, it seems appropriate to search for a supplemental control strategy .It was demonstrated that peak of the diseases incidence is occurred at flowering stage and irrigation cut-off in this time may be reduced the diseases density. Materials and methods This experiment was conducted in a split-split-plot arrangement in randomized complete block design with three replications in research farm of Shahid Bahonar University of Kerman at 2014. The experimental treatments were irrigation (complete irrigation and cut-off the irrigation in flowering stage assigned to main plots, foliar application of spermidine (0, 1 and 2 Mm as subplot and cumin ecotypes (Kerman, Khorasan and Esfahan that was randomized in sub-subplot. The seedbed preparation was made based on common practices at the location. Plots size under the trial was 4 m×3 m so as to get 50 cm inter row spacing in six rows. The ideal density of the crops was considered as 120 plant.m-2. As soon as the seeds were sown, irrigation

  10. Assessment of Qualitative and Quantitative Characters of Two Persian Clover Ecotypes Inoculated by Rhizobium leguminosarum biovartrifoli and Pesudomonas putida Bacteria

    Directory of Open Access Journals (Sweden)

    R Azamei

    2016-02-01

    Full Text Available Introduction Over the past decades, world attitude has changed towards the reduction of environmental pollutants. Harmful effects of synthetic fertilizers on environment have been identified. Bio-fertilizers are not harmful to the environment, but also they have favorable effects on plant growth processes. Soil biotechnology can be defined as the study of soil organisms and their metabolic processes which may have positive effects on plant yields. The main goal of this study is to asess the biotechnology fertilizers beneficial effects on soil organisms and their subsequently to maximize the yield. It is also our desire conside the soil quality, hygiene and environmental protection along this process. Among the strain of nitrogen-fixing bacteria, symbiotic bacteria such as rhizobium bacteria are important and essential in planning the sustainable farming systems. Several studies have shown that crop varieties which inoculated with rhizobium and pseudomonas were superior in yield production and performance. Material and Methods An experiment was designed as factorial performed in randomized complete block design (RCBD with three replications in Agricultural Research Center of Golpayegan (Isfahan during 2010 – 2011. the purpose of this study was to evaluate the effects of inoculation of two ecotypes of Persian clover by various strains of Rhizobium leguminosarum. Biovar trifoli bacteria accompanied with plant growth promoting rhizobacteria (PGPR Pseudomonas putida was employed to find certain qualitative and quantitative characteristics of clover yield, The main plots included two local ecotypes of Persian clover; Arak Haft Chin (V1 and Isfahan Haft Chin (V2, the subplots included inoculation by two strain of Rhizobium; Rb-3, Rb-13 and one strain of Pseudomonas; PS -168.4 cuts were performed during the experiment and 60 kg/ha seed was used for cultivation based on local knowledge. According to recommendations of the Institute of Soil and Water

  11. Ecotypic differentiation between urban and rural populations of the grasshopper Chorthippus brunneus relative to climate and habitat fragmentation.

    Science.gov (United States)

    San Martin Y Gomez, Gilles; Van Dyck, Hans

    2012-05-01

    Urbanization alters environmental conditions in multiple ways and offers an ecological or evolutionary challenge for organisms to cope with. Urban areas typically have a warmer climate and strongly fragmented herbaceous vegetation; the urban landscape matrix is often assumed to be hostile for many organisms. Here, we addressed the issue of evolutionary differentiation between urban and rural populations of an ectotherm insect, the grasshopper Chorthippus brunneus. We compared mobility-related morphology and climate-related life history traits measured on the first generation offspring of grasshoppers from urban and rural populations reared in a common garden laboratory experiment. We predicted (1) the urban phenotype to be more mobile (i.e., lower mass allocation to the abdomen, longer relative femur and wing lengths) than the rural phenotype; (2) the urban phenotype to be more warm adapted (e.g., higher female body mass); and (3) further evidence of local adaptation in the form of significant interaction effects between landscape of origin and breeding temperature. Both males and females of urban origin had significantly longer relative femur and wing lengths and lower mass allocation to the abdomen (i.e., higher investment in thorax and flight muscles) relative to individuals of rural origin. The results were overall significant but small (2-4%). Body mass and larval growth rate were much higher (+10%) in females of urban origin. For the life history traits, we did not find evidence for significant interaction effects between the landscape of origin and the two breeding temperatures. Our results point to ecotypic differentiation with urbanization for mobility-related morphology and climate-related life history traits. We argue that the warmer urban environment has an indirect effect through longer growth season rather than direct effects on the development.

  12. Effect of Drought Stress on Leaf Water Status, Electrolyte Leakage, Photosynthesis Parameters and Chlorophyll Fluorescence of Two Kochia Ecotypes (Kochia scoparia Irrigated With Saline Water

    Directory of Open Access Journals (Sweden)

    A Masoumi

    2012-12-01

    Full Text Available Rainfall deficiency and the development of salinity in Iran are the most important factors for using new salt and drought-resistant plants instead of conventional crops. Kochia species have recently attracted the attention of researchers as a forage and fodder crop in marginal lands worldwide due to its drought and salt tolerant characteristics. This field experiment was performed at the Salinity Research Station of Ferdowsi University of Mashhad, Iran, in a split plot based on randomized complete block design with three replications in 2008. Drought stress, including four levels (control, no irrigation in vegetative stage, no irrigation at reproductive stage and no irrigation at maturity stage for four weeks, and two Kochia ecotypes (Birjand and Borujerd were allocated as main and sub plots, respectively. Relative water content, electrolyte leakage, photosynthesis parameters and chlorophyll fluorescence were assayed every two week from late vegetative stage. Results showed that drought stress decreased significantly measured parameters in plants under stress, in all stages. Plants completely recovered after eliminating stress and rewatering and recovered plants did not show significant difference with control. Electrolyte leaking and chlorophyll fluorescence showed the lowest change among the measured parameters. It can emphasize that resistant to stress conditions in this plant and cell wall is not damaged at this level of stress situation. Birjand ecotype from the arid region, revealed a better response than Borujerd ecotype to drought stress. Probably it returns to initial adaptation of Birjand. In general this plant can recover after severe drought stress well. It is possible to introduce this plant as a new fodder in arid and saline conditions.

  13. To grow or to seed: ecotypic variation in reproductive allocation and cone production by young female Aleppo pine (Pinus halepensis, Pinaceae).

    Science.gov (United States)

    Climent, José; Prada, M Aránzazu; Calama, Rafael; Chambel, M Regina; de Ron, David Sánchez; Alía, Ricardo

    2008-07-01

    Age and size at the first reproduction and the reproductive allocation of plants are linked to different life history strategies. Aleppo pine only reproduces through seed, and, as such, early female reproduction confers high fitness in its infertile highly fire-prone habitats along the Mediterranean coast because life expectancy is short. We investigated the extent of ecotypic differentiation in female reproductive allocation and examined the relation between early female reproduction and vegetative growth. In a common-garden experiment, the threshold age and size at first female reproduction and female reproductive allocation at age seven differed significantly among Aleppo pine provenances of ecologically distinct origin. Significant correlations among reproductive features of the provenances and the ecological traits of origin were found using different analytical tools. In nonlinear models of cone counts vs. stem volume, medium-sized trees (not the largest trees) produced the highest cone yield, confirming that, at the individual level, early female reproduction is incompatible with fast vegetative growth. The contribution of founder effects and adaptation to contrasting fire regimes may be confounding factors. But considering all traits analyzed, the geographical patterns of resource allocation by Aleppo pine suggest ecotypic specialization for either resource-poor (favoring early reproduction) or resource-rich (favoring vegetative growth) habitats.

  14. Lotus japonicus plants of the Gifu B-129 ecotype subjected to alkaline stress improve their Fe(2+) bio-availability through inoculation with Pantoea eucalypti M91.

    Science.gov (United States)

    Campestre, María Paula; Castagno, Luis Nazareno; Estrella, María Julia; Ruiz, Oscar Adolfo

    2016-03-15

    Inoculation assays with Pantoea eucalypti M91 were performed on Lotus japonicus ecotype Gifu. Under alkaline conditions, this ecotype is characterized by the development of interveinal chlorosis of the apical leaves due to low mobilization of Fe(2+). Inoculation with P. eucalypti M91, a plant growth-promoting bacterial strain capable of producing pyoverdine-like and pyochelin-like siderophores under alkaline growth conditions, alters the root, resulting in a herringbone pattern of root branching. Additional features include improvement in Fe(2+) transport to the shoots, acidification of the hydroponic solution of the plant cultures, and an accompanying increase in the efficiency of the PSII parameters. In addition, there was an increase in the expression of the FRO1 and IRT1 genes, accompanied by a significant increase in FRO activity. Results showed that P. eucalypti M91 has a beneficial effect on the Fe acquisition machinery of Strategy I, as described for non-graminaceous monocots and dicots, suggesting its potential as an inoculant for legume crops cultivated in alkaline soils. Copyright © 2016 Elsevier GmbH. All rights reserved.

  15. The molecular dimension of microbial species: 3. Comparative genomics of Synechococcus strains with different light responses and in situ diel transcription patterns of associated ecotypes in the Mushroom Spring microbial mat

    Directory of Open Access Journals (Sweden)

    Millie T. Olsen

    2015-06-01

    Full Text Available Genomes were obtained for three closely related strains of Synechococcus that are representative of putative ecotypes that predominate at different depths in the 1 mm-thick, upper-green layer in the 60°C mat of Mushroom Spring, Yellowstone National Park, and exhibit different light adaptation and acclimation responses. The genomes were compared to the published genome of a previously obtained, closely related strain from a neighboring spring, and differences in both gene content and orthologous gene alleles between high-light-adapted and low-light-adapted strains were identified. Evidence of genetic differences that relate to adaptation to light intensity and/or quality, CO2 uptake, nitrogen metabolism, organic carbon metabolism, and uptake of other nutrients were found between strains of the different putative ecotypes. In situ diel transcription patterns of genes, including genes unique to either low-light-adapted or high-light-adapted strains and different alleles of an orthologous photosystem gene, revealed that expression is fine-tuned to the different light environments experienced by ecotypes prevalent at various depths in the mat. This study suggests that strains of closely related putative ecotypes have different genomic adaptations that enable them to inhabit distinct ecological niches while living in close proximity within a microbial community.

  16. 绿色生态型城市道路评价指标体系%Evaluation index system of green ecotype city road

    Institute of Scientific and Technical Information of China (English)

    李满良; 郑晨; 王朝辉; 曾伟; 狄升贯

    2015-01-01

    In order to evaluate green ecotype city road scientifically and rationally,the concept of green ecotype city road was proposed,and the evaluation index system was set up from 5 aspects, namely,rationality of design,effect of road function,energy-conservation and emission-reduction effect,greening effect and environmental protection effect.5 first grade indexes,14 second grade indexes and 31 third grade indexes were elaborated, and their evaluation standards were determined.The evaluation method of green ecotype city road was established on the basis of Spearman rank correlation coefficient combination determining method and interval approximation method.The green ecotype road of China-Singapore Tianjin Ecotype City was evaluated by using the method and the index system.Evaluation result shows that for the road,21 third grade indexes are excellent and 10 third grade indexes are good.12 second grade indexes are excellent and 2 second grade indexes are good.2 first grade indexes,namely,rationality of design and environmental protection effect are good and the rest are excellent.The distance between the excellent evaluation grade and the evaluation index set of green ecotype city road is 3.82,and is smallest in the distances between the evaluation index set and the evaluation grades,which shows the green ecotype city road is excellent and the evaluation result is consistent with the reality.Therefore,the evaluation index system and the evaluation method are reasonable and reliable.34 tabs,21 refs.%为科学合理地评价绿色生态型城市道路,确立了绿色生态型城市道路概念,从设计合理性、道路功能效果、节能减排效果、绿化效果和环境保护效果五方面提出了绿色生态型城市道路评价指标体系,包括5个一级指标、14个二级指标与31个三级指标,并对各指标进行了阐述,确定了各指标的评价标准,提出了基于 Spearman 等级相关系数组合赋权方法与区间逼近方法

  17. The Effects of Drought Stress on Yield, Yield Components and Anti-oxidant of Two Garlic (Allium sativum L. Ecotypes with Different Planting Densities

    Directory of Open Access Journals (Sweden)

    shiva akbari

    2016-07-01

    Full Text Available Introduction Drought stress reduces plant growth by affecting various physiological and biochemical processes, such as photosynthesis, respiration, translocation, ion uptake, carbohydrates, nutrient metabolism and growth promoters. Garlic (Allium sativum L. is an annual bulb crop that has been cultivated since ancient times and was used as a spice and condiment for many centuries. Garlic is an important plant because of its pharmaceutical properties. The optimum yield of this bulb crop depends on well-managed irrigation, fertilization and cultivation practices. In the final and middle stages of growth, garlic is sensitive to water stress and low irrigation is unsuitable in these stages. This experiment was established to study the influence of drought stress and planting density on yield and its components and the non-enzymatic anti-oxidant content of two different garlic ecotypes. Materials and methods This study was conducted in 2011-2012 in a farmland at the south east of Semnan city. The experimental layout was a split-plot factorial with a randomized complete block design with three replications. The treatments were comprised of three factors: irrigation rates (60%, 80% and 100% of estimated crop evapotranspiration (ETC as the main plot and the factorial combination of three levels of planting density (30, 40 and 50 plants.m-2 and two ecotypes (Tabas and Toroud as the sub-plots. To estimate the crop water requirement, different meteorological parameters were collected from Semnan weather station and were used based on FAO-56 water irrigation calculation instructions. After harvesting, ten garlic plants were sampled randomly in each plot and bulb yield components were measured. To calculate the leaves anti-oxidant content, DPPH method was used. The statistical significances of mean values were assessed by analysis of variance and LSD tests at p≤0.05. All calculations were performed using SAS and Mstat-C softwares. Results and discussion

  18. Effect of Organic and Chemical Fertilizers on Yield and Essential Oil of Two Ecotypes of Savory (Satureja hortensis L. under Normal and Drought Stress Conditions

    Directory of Open Access Journals (Sweden)

    O Akrami nejad

    2016-02-01

    Full Text Available Introduction Savory (Satureja hortensis L. is an annual and aromatic plant from Labiatae family, which has plenty of essential oil and is important in medicinal, food, health and beauty industries (6. In comparison with chemical fertilizers, organic fertilizers especially manure have lots of organic material sources, and can be used as nutrients, especially Nitrogen, Phosphor and Potassium. Organic fertilizers also keeps more water in the soil (14. Water deficit is one of the most important boundaries of production in arid and semi-arid regions. Drought stress reduces water content, limits plant growth and changes some physiological and metabolic activities (31. This experiment was conducted as there is a global interest for production of medicinal plants with sustainable agriculture system, and with low input and shortage of information about Savory reaction to fertilization in drought stress condition. The objective of this research was to compare the effects of chemical fertilizers and different organic fertilizers on quantitative and qualitative characteristics of two ecotypes of savory under drought stress condition. Materials and Methods In order to study the effects of organic and mineral (N, P and K fertilizers on quantitative and qualitative characteristics of savory in drought stress condition, two separate split plot designs with three replications were carried out in 2012-2013 year, at the research field of Shahid Bahonar University of Kerman, Iran. In each design fertilizers including cow manure (30 ton per hectare, poultry manure (10 ton per hectare, chemical fertilizers (used equally with macro elements existing in both poultry and cow manure and control (no fertilizer were used as main factor. Kerman and Khuzestan ecotypes were sub-factor. One of the experiments was irrigated to 100% and the other to 50% of field capacity. Two experiments were analyzed as a combined design. The important characteristics of Savory such as plant

  19. Nickel-tolerant ectomycorrhizal Pisolithus albus ultramafic ecotype isolated from nickel mines in New Caledonia strongly enhance growth of the host plant Eucalyptus globulus at toxic nickel concentrations.

    Science.gov (United States)

    Jourand, Philippe; Ducousso, Marc; Reid, Robert; Majorel, Clarisse; Richert, Clément; Riss, Jennifer; Lebrun, Michel

    2010-10-01

    Ectomycorrhizal (ECM) Pisolithus albus (Cooke & Massee), belonging to the ultramafic ecotype isolated in nickel-rich serpentine soils from New Caledonia (a tropical hotspot of biodiversity) and showing in vitro adaptive nickel tolerance, were inoculated to Eucalyptus globulus Labill used as a Myrtaceae plant-host model to study ectomycorrhizal symbiosis. Plants were then exposed to a nickel (Ni) dose-response experiment with increased Ni treatments up to 60 mg kg( - )(1) soil as extractable Ni content in serpentine soils. Results showed that plants inoculated with ultramafic ECM P. albus were able to tolerate high and toxic concentrations of Ni (up to 60 μg g( - )(1)) while uninoculated controls were not. At the highest Ni concentration tested, root growth was more than 20-fold higher and shoot growth more than 30-fold higher in ECM plants compared with control plants. The improved growth in ECM plants was associated with a 2.4-fold reduction in root Ni concentration but a massive 60-fold reduction in transfer of Ni from root to shoots. In vitro, P. albus strains could withstand high Ni concentrations but accumulated very little Ni in its tissue. The lower Ni uptake by mycorrhizal plants could not be explained by increased release of metal-complexing chelates since these were 5- to 12-fold lower in mycorrhizal plants at high Ni concentrations. It is proposed that the fungal sheath covering the plant roots acts as an effective barrier to limit transfer of Ni from soil into the root tissue. The degree of tolerance conferred by the ultramafic P. albus isolates to growth of the host tree species is considerably greater than previously reported for other ECM. The primary mechanisms underlying this improved growth were identified as reduced Ni uptake into the roots and markedly reduced transfer from root to shoot in mycorrhizal plants. The fact that these positive responses were observed at Ni concentrations commonly observed in serpentinic soils suggests that

  20. Phenolic Composition and Antioxidant and Antiproliferative Activities of the Extracts of Twelve Common Bean (Phaseolus vulgaris L. Endemic Ecotypes of Southern Italy before and after Cooking

    Directory of Open Access Journals (Sweden)

    Maria Neve Ombra

    2016-01-01

    Full Text Available Beans are important dietary components with versatile health benefits. We analysed the extracts of twelve ecotypes of Phaseolus vulgaris in order to determine their phenolic profiles, antioxidant activity, and the in vitro antiproliferative activity. Ultra-performance liquid chromatography with diode array detector (UPLC-DAD admitted us to detect and quantify some known polyphenols, such as gallic acid, chlorogenic acid, epicatechin, myricetin, formononetin, caffeic acid, and kaempferol. The antioxidant activity (AA ranged from 1.568 ± 0.041 to 66.572 ± 3.197 mg necessary to inhibit the activity of the 2,2-diphenyl-1-picrylhydrazyl (DPPH radical by 50% (EC50. The extracts, except those obtained from the nonpigmented samples, were capable of inhibiting the proliferation of the human epithelial colorectal adenocarcinoma (Caco-2 cells, human breast cancer cells MCF-7, and A549 NSCLC cell line. Cultivars differed in composition and concentration of polyphenols including anthocyanins; cooking affected the antioxidant activity only marginally. Qualitative and quantitative differences in phenolic composition between the groups of beans influenced the biological activities; on the other hand, we did not find significant differences on the biological activities within the same variety, before and after cooking.

  1. Diversity of Mat-Forming Fungi in Relation to Soil Properties, Disturbance, and Forest Ecotype at Crater Lake National Park, Oregon, USA

    Directory of Open Access Journals (Sweden)

    James M. Trappe

    2012-04-01

    Full Text Available In forest ecosystems, fungal mats are functionally important in nutrient and water uptake in litter and wood decomposition processes, in carbon resource allocation, soil weathering and in cycling of soil resources. Fungal mats can occur abundantly in forests and are widely distributed globally. We sampled ponderosa pine/white fir and mountain hemlock/noble fir communities at Crater Lake National Park for mat-forming soil fungi. Fungus collections were identified by DNA sequencing. Thirty-eight mat-forming genotypes were identified; members of the five most common genera (Gautieria, Lepiota, Piloderma, Ramaria, and Rhizopogon comprised 67% of all collections. The mycorrhizal genera Alpova and Lactarius are newly identified as ectomycorrhizal mat-forming taxa, as are the saprotrophic genera Flavoscypha, Gastropila, Lepiota and Xenasmatella. Twelve typical mat forms are illustrated, representing both ectomycorrhizal and saprotrophic fungi that were found. Abundance of fungal mats was correlated with higher soil carbon to nitrogen ratios, fine woody debris and needle litter mass in both forest ecotypes. Definitions of fungal mats are discussed, along with some of the challenges in defining what comprises a fungal “mat”.

  2. Comparative study of growth traits and haematological parameters of Anak and Nigerian heavy ecotype chickens fed with graded levels of mango seed kernel (Mangifera indica) meal.

    Science.gov (United States)

    Mbunwen, Ndofor-Foleng Harriet; Ngongeh, Lucas Atehmengo; Okolie, Peter Nzeribe; Okoli, Emeka Linus

    2015-08-01

    One hundred fifty Anak and 120 Nigerian heavy local ecotype (NHLE) chickens were used to study the effects of feeding graded levels of mango seed kernel meal (MKM) replacing maize diet on growth traits and haematological parameters. A 2 × 5 factorial arrangement was employed: two breeds and five diets. The birds were randomly allocated to five finisher diets formulated such that MKM replaced maize at 0, 10, 20, 30 and 40% (T1, T2, T3, T4 and T5) inclusion levels, respectively. The effect of breed and dietary treatments on growth performance and blood characteristics were determined. The results showed a significant (P  0.05) when the breeds and treatments were compared. It was concluded that inclusion of dietary MKM below 30% could replace maize in the diets of Anak and NHLE growing chickens without adverse effect on growth performance and blood constituents. This work suggests that genetic differences exist in growth traits of these breeds of chickens. This advantage could be useful in breed improvement programmes and better feeding managements of the NHLE and Anak chickens.

  3. The Development Trend of Modern Ecotype City Park%现代生态型城市公园的发展趋势

    Institute of Scientific and Technical Information of China (English)

    陈宇夫

    2014-01-01

    Along with the country to vigorously promote the process of urbanization, the number of ecotype city park has a significant increase with the city. Establishing the correct dir-ection of ecological city park development, pursuing formal di-versity and integrated into the overal city planning, enhancing the utilization of natural resources, and strengthening the main color, constructing the network management platform, is of gr-eat significance for the sustainable development of ecological city park.%伴随国家大力推进城镇化进程,城市生态公园的数量随城市数量而大量增加。确立正确的城市生态公园发展方向,追求形式多样性的同时融入城市整体规划,加强自然资源的利用,强化主体色彩,建设网络管理平台,对于城市生态公园的可持续发展具有重要意义。

  4. Phenolic Composition and Antioxidant and Antiproliferative Activities of the Extracts of Twelve Common Bean (Phaseolus vulgaris L.) Endemic Ecotypes of Southern Italy before and after Cooking.

    Science.gov (United States)

    Ombra, Maria Neve; d'Acierno, Antonio; Nazzaro, Filomena; Riccardi, Riccardo; Spigno, Patrizia; Zaccardelli, Massimo; Pane, Catello; Maione, Mena; Fratianni, Florinda

    2016-01-01

    Beans are important dietary components with versatile health benefits. We analysed the extracts of twelve ecotypes of Phaseolus vulgaris in order to determine their phenolic profiles, antioxidant activity, and the in vitro antiproliferative activity. Ultra-performance liquid chromatography with diode array detector (UPLC-DAD) admitted us to detect and quantify some known polyphenols, such as gallic acid, chlorogenic acid, epicatechin, myricetin, formononetin, caffeic acid, and kaempferol. The antioxidant activity (AA) ranged from 1.568 ± 0.041 to 66.572 ± 3.197 mg necessary to inhibit the activity of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical by 50% (EC50). The extracts, except those obtained from the nonpigmented samples, were capable of inhibiting the proliferation of the human epithelial colorectal adenocarcinoma (Caco-2) cells, human breast cancer cells MCF-7, and A549 NSCLC cell line. Cultivars differed in composition and concentration of polyphenols including anthocyanins; cooking affected the antioxidant activity only marginally. Qualitative and quantitative differences in phenolic composition between the groups of beans influenced the biological activities; on the other hand, we did not find significant differences on the biological activities within the same variety, before and after cooking.

  5. Alterations in the sugar metabolism and in the vacuolar system of mesophyll cells contribute to the desiccation tolerance of Haberlea rhodopensis ecotypes.

    Science.gov (United States)

    Georgieva, K; Rapparini, F; Bertazza, G; Mihailova, G; Sárvári, É; Solti, Á; Keresztes, Á

    2017-01-01

    Haberlea rhodopensis belongs to the small group of resurrection plants having the unique ability to survive desiccation to air dry state retaining most of its chlorophyll content and then resume normal function upon rehydration. It prefers the shady valleys and northward facing slopes of limestone ridges in mountain zones with high average humidity. Nevertheless, it can be found rarely on rocks directly exposed to the sunlight, without the coverage of the canopy. In the present study, we follow the alterations in the subcellular organization of mesophyll cells and sugar metabolism upon desiccation of shade and sun H. rhodopensis plants. Composition and content of soluble carbohydrates during desiccation and rehydration were different in plants grown below the trees or on the sunny rocks. Sucrose, however, was dominating in both ecotypes. The amount of starch grains in chloroplasts was inversely related to that of sugars. Concomitantly with these changes, the number of vacuoles was multiplied in the cells. This can be explained by the development of small (secondary) vacuoles peripherally in the cytoplasm, rather than by the fragmentation of the single vacuole, proposed earlier in the literature. Accordingly, the centripetal movement of chloroplasts and other organelles may be a result of the dynamic changes in the vacuolar system. Upon rehydration, the inner vacuoles enlarged and the organelles returned to their normal position.

  6. Leaf cuticular lipids on the Shandong and Yukon ecotypes of saltwater cress, Eutrema salsugineum, and their response to water deficiency and impact on cuticle permeability.

    Science.gov (United States)

    Xu, Xiaojing; Feng, Jinchao; Lü, Shiyou; Lohrey, Greg T; An, Huiling; Zhou, Yijun; Jenks, Matthew A

    2014-08-01

    The impact of water-deficit stress on leaf cuticular waxes and cutin monomers, and traits associated with cuticle permeability were examined in Shandong and Yukon ecotypes of Eutrema salsugineum (syn. Thellungiella salsuginea). Although Shandong exhibits glaucous leaves, and Yukon is non-glaucous, wax amounts on non-stressed Yukon leaves were 4.6-fold higher than on Shandong, due mainly to Yukon's eightfold higher wax fatty acids, especially the C22 and C24 acid homologues. Water deficit caused a 26.9% increase in total waxes on Shandong leaves, due mainly to increased C22 and C24 acids; and caused 10.2% more wax on Yukon, due mainly to an increase in wax alkanes. Total cutin monomers on non-stressed leaves of Yukon were 58.3% higher than on Shandong. Water deficit caused a 28.2% increase in total cutin monomers on Shandong, whereas total cutin monomers were not induced on Yukon. With or without stress, more abundant cuticle lipids were generally associated with lower water loss rates, lower chlorophyll efflux rates and an extended time before water deficit-induced wilting. In response to water deficit, Shandong showed elevated transcription of genes encoding elongase subunits, consistent with the higher stress induction of acids by Shandong. Yukon's higher induction of CER1 and CER3 transcripts may explain why alkanes increased most on Yukon after water deficit. Eutrema, with its diverse cuticle lipids and responsiveness, provides a valuable genetic resource for identifying new genes and alleles effecting cuticle metabolism, and lays groundwork for studies of the cuticle's role in extreme stress tolerance.

  7. Comprehensive genomic analyses of the OM43 clade including a novel species from Red Sea indicate ecotype differentiation among marine methylotrophs

    KAUST Repository

    Jimenez Infante, Francy M.

    2015-12-11

    The OM43 clade within the family Methylophilaceae of Betaproteobacteria represents a group of methylotrophs playing important roles in the metabolism of C1 compounds in marine environments and other aquatic environments around the globe. Using dilution-to-extinction cultivation techniques, we successfully isolated a novel species of this clade (designated here as MBRS-H7) from the ultra-oligotrophic open ocean waters of the central Red Sea. Phylogenomic analyses indicate that MBRS-H7 is a novel species, which forms a distinct cluster together with isolate KB13 from Hawaii (H-RS cluster) that is separate from that represented by strain HTCC2181 (from the Oregon coast). Phylogenetic analyses using the robust 16S–23S internal transcribed spacer revealed a potential ecotype separation of the marine OM43 clade members, which was further confirmed by metagenomic fragment recruitment analyses that showed trends of higher abundance in low chlorophyll and/or high temperature provinces for the H-RS cluster, but a preference for colder, highly productive waters for the HTCC2181 cluster. This potential environmentally driven niche differentiation is also reflected in the metabolic gene inventories, which in the case of H-RS include those conferring resistance to high levels of UV irradiation, temperature, and salinity. Interestingly, we also found different energy conservation modules between these OM43 subclades, namely the existence of the NADH:quinone oxidoreductase NUO system in the H-RS and the non-homologous NQR system in HTCC2181, which might have implications on their overall energetic yields.

  8. Ecological speciation in an island snail: evidence for the parallel evolution of a novel ecotype and maintenance by ecologically dependent postzygotic isolation.

    Science.gov (United States)

    Stankowski, Sean

    2013-05-01

    Speciation is the process by which reproductive isolation evolves between populations. Two general models of speciation have been proposed: ecological speciation, where reproductive barriers evolve due to ecologically based divergent selection, and mutation-order speciation, where populations fix different mutations as they adapt to similar selection pressures. I evaluate these alternative models and determine the progress of speciation in a diverse group of land snails, genus Rhagada, inhabiting Rosemary Island. A recently derived keeled-flat morphotype occupies two isolated rocky hills, while globose-shelled snails inhabit the surrounding plains. The study of one hill reveals that they are separated by a narrow hybrid zone. As predicted by ecological speciation theory, there are local and landscape level associations between shell shape and habitat, and the morphological transition coincides with a narrow ecotone between the two distinct environments. Microsatellite DNA revealed a cline of hybrid index scores much wider than the morphological cline, further supporting the ecological maintenance of the morphotypes. The hybrid zone does not run through an area of low population density, as is expected for mutation-order hybrid zones, and there is a unimodal distribution of phenotypes at the centre, suggesting that there is little or no prezygotic isolation. Instead, these data suggest that the ecotypes are maintained by ecologically dependent postzygotic isolation (i.e. ecological selection against hybrids). Mitochondrial and Microsatellite DNA indicate that the keeled-flat form evolved recently, and without major historical disruptions to gene flow. The data also suggest that the two keeled-flat populations, inhabiting similar rocky hills, have evolved in parallel. These snails provide a complex example of ecological speciation in its early stages.

  9. Selection and Validation of Reference Genes for Real-Time Quantitative PCR in Hyperaccumulating Ecotype of Sedum alfredii under Different Heavy Metals Stresses

    Science.gov (United States)

    Liu, Mingying; Qiao, Guirong; Jiang, Jing; Zhuo, Renying

    2013-01-01

    Real-time Quantitative PCR (RT-qPCR) has become an effective method for accurate analysis of gene expression in several biological systems as well as under different experimental conditions. Although with high sensitivity, specificity and broad dynamic range, this method requires suitable reference genes for transcript normalization in order to guarantee reproducible and meaningful results. In the present study, we evaluated five traditional housekeeping genes and five novel reference genes in Hyperaccumulating ecotype of Sedum alfredii, a well known hyperaccumulator for heavy metals phytoremediation, under Cd, Pb, Zn and Cu stresses of seven different durations. The expression stability of these ten candidates were determined with three programs - geNorm, NormFinder and BestKeeper. The results showed that all the selected reference genes except for SAND could be used for RT-qPCR normalization. Among them UBC9 and TUB were ranked as the most stable candidates across all samples by three programs together. For the least stable reference genes, however, BestKeeper produced different results compared with geNorm and NormFinder. Meanwhile, the expression profiles of PCS under Cd, Pb, Zn and Cu stresses were assessed using UBC9 and TUB respectively, and similar trends were obtained from the results of the two groups. The distinct expression patterns of PCS indicated that various strategies could be taken by plants in adaption to different heavy metals stresses. This study will provide appropriate reference genes for further gene expression quantification using RT-qPCR in Hyperaccumulator S. alfredii. PMID:24340067

  10. Comprehensive Genomic Analyses of the OM43 Clade, Including a Novel Species from the Red Sea, Indicate Ecotype Differentiation among Marine Methylotrophs

    Science.gov (United States)

    Jimenez-Infante, Francy; Ngugi, David Kamanda; Vinu, Manikandan; Alam, Intikhab; Kamau, Allan Anthony; Blom, Jochen; Bajic, Vladimir B.

    2015-01-01

    The OM43 clade within the family Methylophilaceae of Betaproteobacteria represents a group of methylotrophs that play important roles in the metabolism of C1 compounds in marine environments and other aquatic environments around the globe. Using dilution-to-extinction cultivation techniques, we successfully isolated a novel species of this clade (here designated MBRS-H7) from the ultraoligotrophic open ocean waters of the central Red Sea. Phylogenomic analyses indicate that MBRS-H7 is a novel species that forms a distinct cluster together with isolate KB13 from Hawaii (Hawaii-Red Sea [H-RS] cluster) that is separate from the cluster represented by strain HTCC2181 (from the Oregon coast). Phylogenetic analyses using the robust 16S-23S internal transcribed spacer revealed a potential ecotype separation of the marine OM43 clade members, which was further confirmed by metagenomic fragment recruitment analyses that showed trends of higher abundance in low-chlorophyll and/or high-temperature provinces for the H-RS cluster but a preference for colder, highly productive waters for the HTCC2181 cluster. This potential environmentally driven niche differentiation is also reflected in the metabolic gene inventories, which in the case of the H-RS cluster include those conferring resistance to high levels of UV irradiation, temperature, and salinity. Interestingly, we also found different energy conservation modules between these OM43 subclades, namely, the existence of the NADH:quinone oxidoreductase complex I (NUO) system in the H-RS cluster and the nonhomologous NADH:quinone oxidoreductase (NQR) system in the HTCC2181 cluster, which might have implications for their overall energetic yields. PMID:26655752

  11. Research on the effects of winter protection for grape with ecotype arch-tile units%酿酒葡萄园生态型弓瓦防寒效果研究

    Institute of Scientific and Technical Information of China (English)

    李映龙; 单守明; 平吉成; 张军翔

    2011-01-01

    Based on testing new type units of winter protection for wine grape, instead of burying earth soft which is traditional measure for cold prevention in winter, we studied influence of soil temperature on grape roots (Cabernet Sauvignon) by ecotype arch-tile units. Result showed that soil temperatures dealing with ecotype arch-tile units were higher than those with burying earth soil treatment, but not significant. In the spring, mortality of branches and tendrils with arch-tile units was slightly higher than that with burying earth soil treatment; Differences did not reach a significant level, but fracture rate of new shoots with arch-tile units is significantly lower than that with burying earth soil treatment. Therefore, under the experimental conditions, the effects of winter protection by ecotype arch-tile units equal to that of burying earth soil, ecotype arch-tile units were able to make over-wintering Cabernet grapes live safely.%为了探索能替代葡萄冬季埋土防寒措施的新型防寒装置,本试验以赤霞珠葡萄为材料,研究生态型弓瓦防寒装置对葡萄根系土层温度的影响,结果表明,弓瓦防寒装置处理的各土层温度高于埋土处理,但是差异不显著.在春季,弓瓦处理的枝蔓死亡率略高于埋土处理;差异没有达到显著水平,但是新梢折断率显著低于埋土处理,因此,在试验条件下,生态型弓瓦防寒装置的防寒效果和埋土防寒措施相当,可以使赤霞珠葡萄安全越冬.

  12. Sinorhizobium meliloti-induced chitinase gene expression in Medicago truncatula ecotype R108-1: a comparison between symbiosis-specific class V and defence-related class IV chitinases.

    Science.gov (United States)

    Salzer, Peter; Feddermann, Nadja; Wiemken, Andres; Boller, Thomas; Staehelin, Christian

    2004-08-01

    The Medicago truncatula (Gaertn.) ecotypes Jemalong A17 and R108-1 differ in Sinorhizobium meliloti-induced chitinase gene expression. The pathogen-inducible class IV chitinase gene, Mtchit 4, was strongly induced during nodule formation of the ecotype Jemalong A17 with the S. meliloti wild-type strain 1021. In the ecotype R108-1, the S. meliloti wild types Sm1021 and Sm41 did not induce Mtchit 4 expression. On the other hand, expression of the putative class V chitinase gene, Mtchit 5, was found in roots of M. truncatula cv. R108-1 nodulated with either of the rhizobial strains. Mtchit 5 expression was specific for interactions with rhizobia. It was not induced in response to fungal pathogen attack, and not induced in roots colonized with arbuscular mycorrhizal (AM) fungi. Elevated Mtchit 5 gene expression was first detectable in roots forming nodule primordia. In contrast to Mtchit 4, expression of Mtchit 5 was stimulated by purified Nod factors. Conversely, Mtchit 4 expression was strongly elevated in nodules formed with the K-antigen-deficient mutant PP699. Expression levels of Mtchit 5 were similarly increased in nodules formed with PP699 and its parental wild-type strain Sm41. Phylogenetic analysis of the deduced amino acid sequences of Mtchit 5 (calculated molecular weight = 41,810 Da, isoelectric point pH 7.7) and Mtchit 4 (calculated molecular weight 30,527 Da, isoelectric point pH 4.9) revealed that the putative Mtchit 5 chitinase forms a separate clade within class V chitinases of plants, whereas the Mtchit 4 chitinase clusters with pathogen-induced class IV chitinases from other plants. These findings demonstrate that: (i) Rhizobium-induced chitinase gene expression in M. truncatula occurs in a plant ecotype-specific manner, (ii) Mtchit 5 is a putative chitinase gene that is specifically induced by rhizobia, and (iii) rhizobia-specific and defence-related chitinase genes are differentially influenced by rhizobial Nod factors and K antigens.

  13. Ecotypic and allozyme variation of Capsella bursa-pastoris and C. rubella (Brassicaceae along latitude and altitude gradients on the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    Hoffrogge, Raimund

    1999-12-01

    Full Text Available Life-history traits (onset of flowering, leaf number, rosette diameter, plant height, branching number, fruit dimensions, seed number of Capsella species from the Iberian Península associated with colotúzing ability were compared in a random block field experiment. Data were evaluated by a principal component analysis. Allozymes (AAT, LAP, GDH and leaf types were recorded. C. bursa-pastoris plants originating from low and high elevations of the summer dry Mediterranean climatic zone (Sierra Nevada were early flowering, whereas those originating from the Pyrenees with an alpine climate were late. In C. bursa-pastoris the "rhomboidea" leaf type was very frequent, whereas in C. rubella it was the "heteris" leaf type. There was a change of leaf type frequencies along geographical clines which is explained by adaptive components of the leaf shape. The allozymes displayed a geographical distribuüon pattem and in C. bursa-pastoris a certain multilocus genotype appeared to be a molecular marker for an early flowering ecotype(inicio de la floración, número de hojas, diámetro de la roseta, altura de la planta, número de ramas, dimensiones del fruto y número de semillas de plantas de Capsella procedentes de la Península Ibérica mediante un experimento de bloques aleatorios en el campo. Los datos se evaluaron con un análisis de componentes principales. También se registraron el tipo de hojas y el perfil aloenzimático de las plantas. Las plantas de Capsella bursa-pastoris procedentes de altitudes altas y bajas de la zona climática Mediterránea de verano seco (Sierra Nevada mostraron ser de floración temprana, mientras que las plantas de los Pirineos, con un clima alpino, presentaron una floración tardía. En C. bursa-pastoris el tipo de hoja "rhomboidea" resultó ser el más frecuente, en tanto que en C. rubella lo fue el tipo "heteris". Se observó un cambio en las frecuencias de los tipos de hojas a lo largo de una clina geográfica, lo

  14. The molecular dimension of microbial species: 2. Synechococcus strains representative of putative ecotypes inhabiting different depths in the Mushroom Spring microbial mat exhibit different adaptive and acclimative responses to light

    Directory of Open Access Journals (Sweden)

    Shane eNowack

    2015-06-01

    Full Text Available Closely related strains of thermophilic Synechococcus were cultivated from the microbial mats found in the effluent channels of Mushroom Spring, Yellowstone National Park (YNP. These strains have identical or nearly identical 16S rRNA sequences but are representative of separate, predicted putative ecotype populations, which were identified by using the more highly resolving psaA locus and which predominate at different vertical positions within the 1-mm-thick upper-green layer of the mat. Pyrosequencing confirmed that each strain contained a single, predominant psaA genotype. Strains differed in growth rate as a function of irradiance. A strain with a psaA genotype corresponding to a predicted putative ecotype that predominates near the mat surface grew fastest at high irradiances, whereas strains with psaA genotypes representative of predominant subsurface populations grew faster at low irradiance and exhibited greater sensitivity to abrupt shifts to high light. The high-light-adapted and low-light-adapted strains also exhibited differences in pigment content and the composition of the photosynthetic apparatus (photosystem ratio when grown under different light intensities. Cells representative of the different strains had similar morphologies under low-light conditions, but under high-light conditions, cells of low-light-adapted strains became elongated and formed short chains of cells. Collectively, the results presented here are consistent with the hypothesis that closely related, but distinct, ecological species of Synechococcus occupy different light niches in the Mushroom Spring microbial mat and acclimate differently to changing light environments.

  15. A rapid and versatile combined DNA/RNA extraction protocol and its application to the analysis of a novel DNA marker set polymorphic between Arabidopsis thaliana ecotypes Col-0 and Landsberg erecta

    Directory of Open Access Journals (Sweden)

    Coupland George

    2005-08-01

    Full Text Available Abstract Background Many established PCR-based approaches in plant molecular biology rely on lengthy and expensive methods for isolation of nucleic acids. Although several rapid DNA isolation protocols are available, they have not been tested for simultaneous RNA isolation for RT-PCR applications. In addition, traditional map-based cloning technologies often use ill-proportioned marker regions even when working with the model plant Arabidopsis thaliana, where the availability of the full genome sequence can now be exploited for the creation of a high-density marker systems. Results We designed a high-density polymorphic marker set between two frequently used ecotypes. This new polymorphic marker set allows size separation of PCR products on agarose gels and provides an initial resolution of 10 cM in linkage mapping experiments, facilitated by a rapid plant nucleic acid extraction protocol using minimal amounts of A. thaliana tissue. Using this extraction protocol, we have also characterized segregating T-DNA insertion mutations. In addition, we have shown that our rapid nucleic acid extraction protocol can also be used for monitoring transcript levels by RT-PCR amplification. Finally we have demonstrated that our nucleic acid isolation method is also suitable for other plant species, such as tobacco and barley. Conclusion To facilitate high-throughput linkage mapping and other genomic applications, our nucleic acid isolation protocol yields sufficient quality of DNA and RNA templates for PCR and RT-PCR reactions, respectively. This new technique requires considerably less time compared to other purification methods, and in combination with a new polymorphic PCR marker set dramatically reduces the workload required for linkage mapping of mutations in A. thaliana utilizing crosses between Col-0 and Landsberg erecta (Ler ecotypes.

  16. Antioxidant system in two ecotypes of reed (Phragmites communis) leaves from different habitats%不同生境两种生态型芦苇的抗氧化系统

    Institute of Scientific and Technical Information of China (English)

    宫海军; 陈坤明; 高永生; 赵志光; 王锁民; 张承烈

    2004-01-01

    以分布于甘肃临泽平川乡的两种芦苇生态型--水生芦苇(水芦)和重度盐化草甸芦苇(盐芦)叶片为材料,研究了其抗氧化系统的特征.结果表明,与水芦相比,盐芦中未出现活性氧和MDA(丙二醛)的积累,抗氧化酶SOD(超氧化物歧化酶)、CAT(过氧化氢酶)、POD(过氧化物酶)和APX(抗坏血酸过氧化物酶)的活性显著升高.总抗坏血酸和类胡萝卜素含量在两种生态型芦苇中没有差异,但还原型抗坏血酸和总谷胱甘肽含量在盐芦中显著升高.而且,盐芦的LOX(脂氧合酶)活性比水芦低.这些结果表明,盐芦中有效的抗氧化防御系统对抵抗盐渍胁迫起着重要的作用.此外,盐芦中高活性的Ca2+- 和 Mg2+-ATPase对细胞中过多离子的转运以及避免离子毒害起着重要的作用.%Using plants possessing stable genetic tolerance/resistance under natural environmental conditions to study the mechanism of plants' adaptation to environmental stress are very significant. However, relevant work is very limited. In this work, two ecotypes of reed (Phragmites communis Trin.), referred to as "swamp reed (SR)" and "heavy salt meadow reed (HSMR)" according to their habitats, growing in Pingchuan Town, Linze County, Gansu Province (China) were investigated for the antioxidant system in their leaves. The results showed that compared with the SR, there were no accumulations of reactive oxygen species and MDA (malondialdehyde) in the HSMR. The activities of SOD (superoxide dismutase), CAT (catalase), POD (peroxidase) and APX (ascorbate peroxidase) were significantly higher in the HSMR than those in the SR. There were no differences in the contents of total ascorbic acid and carotenoids between the two ecotypes, while the contents of reduced ascorbic acid and total glutathione were higher in the HSMR than that in the SR. Moreover, the LOX (lipoxygenase) in the HSMR showed a decreased activity compared with the SR. These results suggested that more

  17. BIOCHEMICAL AND MOLECULAR CHARACTERIZATION OF RED RICE ECOTYPES FROM THE RIO GRANDE DO SUL STATE, BRAZIL CARACTERIZAÇÃO BIOQUÍMICA E MOLECULAR DE ACESSOS DE ARROZ VERMELHO COLETADOS NO ESTADO DO RIO GRANDE DO SUL

    Directory of Open Access Journals (Sweden)

    Gaspar Malone

    2007-09-01

    Full Text Available

    Red rice is one of the most important weeds of cultivated rice in Brazil. On the other hand, red rice constitutes a collection of genes lost during the cultivated rice domestication process and has a fundamental importance for recovery of promising genic constitutions. This study had the objective to analyze the genetic variability of a colletion of red rice (Oryza sativa L. ecotypes from Rio Grande do Sul State, Brazil, through isoenzimatic and microsatellite markers. Thirty four accesses from the Seed and Biotechnology Laboratory germplasm bank, at Federal University of Pelotas, were analyzed using six isoenzimatic systems and nineteen microsatellite markers. Twenty-three biochemical and 54 molecular alleles were identified and used to estimate the polymorphism (PIC and genetic similarity indexes. The analyzed red rice population presents large genetic variability, evidencing the potentiality to map characteristics of interest to seed physiology. Biochemical markers of the isoenzime type and molecular markers of the microsatellite type are efficient to estimate the genetic variability in red rice ecotypes.

    KEY-WORDS: Oryza sativa; biochemical markers; microsatellite markers; genetic variability.

    O arroz vermelho é uma das principais espécies daninhas para cultivo de arroz no Brasil. Por outro lado, constitui-se num acervo de genes perdidos durante a domesticação do arroz cultivado, que poderá ser importante para a recuperação de constituições gênicas promissoras. O objetivo desde trabalho foi analisar a variabilidade genética de uma coleção de acessos de arroz vermelho (Oryza sativa L. coletados no Estado de Rio Grande do Sul, Brasil, através de marcadores bioquímicos do tipo isoenzimas, e marcadores moleculares do tipo microssatélites. Trinta e quatro acessos

  18. 定向转育卵圆生态型大白菜雄性不育系的研究%Directional Breeding of An Oval-ecotype Male Sterile Line of Chinese Cabbage(Brassica campestris L. ssp. pekinensis)

    Institute of Scientific and Technical Information of China (English)

    谭翀; 郭瑛琪; 岳艳玲

    2014-01-01

    [目的]探究大白菜定向转育卵圆生态型雄性不育系的方法。[方法]以大白菜核不育"复等位基因遗传假说"为理论依据,以甲型两用系‘AB12’为不育供体品系,以卵圆生态型可育品系‘06048’为待转育品系,采用杂交、回交、兄妹交和测交的方法,按照定向转育方案将核不育基因定向转育。[结果]各世代育性分离比率与理论相一致,成功育成了一种不育株率100%的具有‘06048’园艺性状的新核不育系,实现了核不育基因和园艺特性的同时转育。[结论]该研究成果验证此定向转育方案是可行的,进一步为基因型为 msms的其他园艺性状的大白菜定向转育提供理论基础,也可以推广应用到整个芸薹属其它经济作物中,极大的拓宽了优良核不育基因的实际应用范围。%Objective] The study aimed to explore the method for directional breeding of a male-sterile line in oval-ecotype Chinese cabbage. [Method] Based on "Multiple Al ele Hypothesis of Genic Male Sterile Chinese Cabbage", an inbred line ‘06048’ of oval ecotype was used as the receptor, and male fertile plant of ‘AB12’ was used as the donor line. Crossing, backcross, selfing, testcross and sibling were ap-plied to transfer the multiple al eles under the directional genetic model. [Result] Segregation ratio of every generation was consistent with theoretical value. A new male sterile line with 100% male sterility and ‘06048’ horticultural traits was ob-tained successful y, which accomplished the transfer of male sterile multiple al ele and horticultural characters of receptor line at the same time. [Conclusion] The re-search verifies that the model of directional transfer is feasible, provides a theoreti-cal basis for the directional transfer of Chinese cabbage with other horticultural traits whose genotype is msms. The model can also be applied to other Brassica crops, to generate genetic male sterile lines

  19. Study on Community Structure of Arthropod in Different Ecotypes of Maize Fields%不同生态型夏玉米田节肢动物群落特征的研究

    Institute of Scientific and Technical Information of China (English)

    辛肇军; 李照会; 叶保华

    2012-01-01

    The composition of arthropod communities in different ecotypes of maize fields were investigated, and the arthropod community characteristics and the relative abundance of each group were analyzed in this paper. The individual numbers, richness, diversity index and evenness index in maize - vegetable and maize - fruit fields were higher than those in maize fields, but the ecological dominance was lower. The number of predacious and parasitic natural enemies in maize fields was less than that in maize - vegetable and maize -fruit fields. The species richness changed obviously in different time series in summer maize fields, which increased rapidly from the middle of July and reached the largest as 61 kinds at August 13, and then decreased gradually until to the lowest point on September 29.%分析了泰安市3种不同生态型夏玉米田节肢动物群落结构组成及相关特征指数、优势种群和优势度,并研究了不同生态型夏玉米田节肢动物群落中各类群的相对多度.结果表明,粮菜区和粮果区节肢动物丰富度、个体总数、多样性指数和均匀度指数均明显高于纯粮区,而生态优势度均明显低于纯粮区,纯粮区捕食性和寄生性天敌种群数量少于粮菜区和粮果区.夏玉米田物种丰富度在不同时间序列上差异明显,自7月中旬开始物种丰富度呈急剧增大趋势,8月13日物种丰富度达最大值61种,此后物种丰富度逐渐波动减少,9月29日达最低点.

  20. Comparison Between Six Ecotypes of Vetiver Grasses in Photosynthetic Light Response and Diurnal Variation of Photosynthetic Parameters%6种生态型香根草光合光响应特征及光合参数日变化的比较

    Institute of Scientific and Technical Information of China (English)

    周强; 胡淑宝; 王青青; 李贵生; 唐丽; 於丙军

    2015-01-01

    A study was carried out in order to investigate differences between six ecotypes of vetiver grasses ( Karnataka, Sunshine, Huffman, Kandy, Monto and Veriveria nermorlis) in photosynthetic physiology and rules of diurnal variation of photosynthetic parameters. Results show that the six ecotypes of vetiver grasses varied sharply in light saturation point (LSP), light compensation point (LCP), maximum net photosynthetic rate (Pn,max), dark respiration rate (Rd) and di⁃urnal variation of net photosynthetic rates ( Pn ) . Among the six ecotypes, Karnataka and Veriveria nermorlis were higher in LSP, LCP and Pn,max; Sunshine and Kandy, lower in LSP; Sunshine and Huffman, lowest in LCP;Monto, lowest in Pn,max;Karnataka, higher in Rd;and Huffman, lower in Rd . Furthermore, the diurnal variations of Pn of Karnataka and Veriveria nermorlis both could be depicted as two single⁃peak curves with Pn,max appearing at 12:00, while the diurnal var⁃iations of Pn of the other four ecotypes, as double⁃peak curves with an obvious midday depression appearing at 12:00. Re⁃lationships of Pn with ecological factors, such as air temperature ( Ta ) , air CO2 concentration ( Ca ) , relative air humidity (HR) and photosynthetically active radiation (PAR), were analyzed by correlation, path and decision coefficients, re⁃spectively, indicating that PAR is the primary determining factor for Pn of the six ecotypes of vetiver grasses, HR , the main limiting factor for Pn of Karnataka, Huffman, Monto and Veriveria nermorlis, and Ta the main limiting factor for Pn of Sun⁃shine and Kandy.%为了研究不同生态型香根草( Vetiveria zizanioides)的光合生理差异,比较了Karnataka、Sunshine、Huffman、Kandy、Monto和Veriveria nermorlis这6种生态型香根草的光合光响应特征和光合参数日变化规律。结果表明,除表观量子效率(AQY)外,6种生态型香根草的光饱和点(LSP)、光补偿点(LCP)、最大

  1. 不同生态型小飞蓬对酸樱桃镉积累及土壤酶活性的影响%Effects of Different Ecotypes of Conyza canadensis on Cd Accumulation of Sour Cherry and Soil Enzyme Activity

    Institute of Scientific and Technical Information of China (English)

    程籍; 廖明安; 林立金; 刘娟; 汤福义; 罗丽; 梅洛银; 刘雨

    2013-01-01

    为研究镉污染下,不同生态型小飞蓬对酸樱桃镉积累及土壤酶活性的影响,通过盆栽试验研究了2类生态型(矿山生态型和非矿山生态型)小飞蓬与酸樱桃混种对2类植物生物量、镉含量及土壤酶活性的影响。结果表明,与矿山生态型和非矿山生态型小飞蓬混种的酸樱桃地上部生物量分别较单种降低了31.92%和34.62%,根系生物量较单种分别降低了42.47%和33.33%;地上部镉含量分别比单种下降35.42%和44.44%,根系的镉含量分别比单种下降17.01%和28.70%。2种混种方式均使土壤有效镉含量、土壤过氧化氢酶活性、土壤脲酶活性较各自单种有所增加,土壤蔗糖酶活性有所下降。因此,2种不同生态型小飞蓬混种酸樱桃,虽然使酸樱桃生长受到一定抑制,但对土壤微生物环境有一定改善效果,且能有效降低酸樱桃对镉的吸收,其中以混种矿山生态型小飞蓬的效果更好。%To study the effects of different ecotypes of Conyza canadensis on cadmium ( Cd ) accumulation of sour cherry and soil enzyme activity ,the pot experiment was adopted to study the effects of intercropping two eco-types(Mining and non-mining ecotype) of Conyza canadensis and sour cherry on their biomass,Cd content and soil enzyme activity .The results showed that , sour cherry intercropping with mining or non-mining ecotype of Conyza canadensis,the shoot biomass were respectively decreased by 31.92%and 34.62%than the monoculture,the root biomass were respectively decreased by 42 .47%and 33 .33%than the monoculture;the Cd content in shoot were respectively decreased by 35 .42%and 44 .44%than the monoculture ,the Cd content in root respectively decreased 17 .01%and 28 .70%than the monoculture .The soil available Cd content ,soil catalase activity ,soil urease activity were respectively increased than the monoculture in both two kinds of intercropping methods

  2. Nutritional Aspects of Six Quinoa (Chenopodium quinoa Willd. Ecotypes from three Geographical Areas of Chile Aspectos Nutricionales de Seis Ecotipos de Quínoa (Chenopodium quinoa Willd. de Tres Zonas Geográficas de Chile

    Directory of Open Access Journals (Sweden)

    Margarita Miranda

    2012-06-01

    Full Text Available This study explored the diversity of the quinoa crop in Chile from a nutritional perspective. Nutritional properties, minerals, vitamins, and saponin content were assessed in seeds of six Chilean quinoa (Chenopodium quinoa Willd. ecotypes grown in three main production areas with distinctive climatic and edaphic conditions: Ancovinto and Cancosa in the North-Altiplano or High Plateau, Cáhuil and Faro in the central coastal area, and Regalona and Villarrica in the south of the country. There were significant differences (P La diversidad en el cultivo de la quinoa (Chenopodium quinoa Willd. de Chile fue explorada desde una perspectiva nutricional. En este contexto las propiedades nutricionales como también los contenidos de minerales, vitaminas y saponina fueron evaluados en las semillas de seis ecotipos chilenos de quínoa, cultivados en las tres principales zonas de producción con condiciones edafoclimáticas distintas: Ancovinto y Cancosa del altiplano del norte, Cáhuil y Faro de la zona costera central y, Regalona y Villarrica en el sur del país. Hubo diferencias significativas (P < 0.05 en todas las propiedades nutricionales de las semillas de todas las zonas. El ecotipo Villarrica tenia el mayor contenido de proteína (16.10 g 100 g-1 MS y de vitamina E y C (4.644 ± 0.240 y 23.065 ± 1.119 mg 100 g-1 MS, respectivamente. El mayor contenido de vitamina B1 (0.648 ± 0.006 mg 100 g-1 MS y B3 (1.569 ± 0.026 mg 100 g-1 MS fue encontrado en el ecotipo Regalona, y el mayor contenido de vitamina B2 (0.081 ± 0.002 mg 100 g-1 MS en el ecotipo Ancovinto. El K fue el mineral más abundante con un valor de 2325.56 mg 100 g-1 MS en el ecotipo Cancosa. El contenido de saponina fluctuó entre 0.84 g 100 g-1 MS en el ecotipo Villarrica y 3.91 g 100 g-1 MS en el ecotipo Cáhuil. Hubo diferencias significativas entre los ecotipos chilenos de quínoa cultivados bajo diferentes condiciones climáticas. No obstante, las semillas de quinoa de cualquier

  3. 生态型辅导员团队建设初探--以湖南电气职业技术学院为个案研究%Preliminary Studies on Political Instructor Ecotype Team Building:A Case Study of Hunan Electrical College of Technology

    Institute of Scientific and Technical Information of China (English)

    匡翠芳; 刘鑫

    2015-01-01

    在高校生态环境中,辅导员的实际生态位受到挤压。本文从生态型辅导员团队建设模式架构、团队精神凝练、团队成长平台搭建、高效服务平台构建四个方面探索生态型辅导员团队建设路径。%The niche of political instructor is being oppressed. This paper aims to explore building an ecotype team through four aspects, namely, the forming of ecological framework model, the imbuing of team spirit, the establishing of teammenber growth platform and the constructing of efficient service platform.

  4. A complementary strategy for the conservation of native forest tree species: retrieval and conservation of threatened ecotypes Estratégia complementar para conservação de espécies florestais nativas: resgate e conservação de ecótipos ameaçados

    Directory of Open Access Journals (Sweden)

    Jarbas Yukio Shimizu

    2010-06-01

    Full Text Available Deforestation has become rampant in recent years in Brazil and has affected all biomes where many
    species are threatened to extinction due to destruction natural habitats. Government initiatives to hinder the
    chain of destruction include two main lines of action: to establish conservation units (parks, reserves and
    others; and programs to encourage plantation of native tree species for reclamation of degraded ecosystems, restoration of forests on permanent protection areas (riparian, and steep slope environments, and establishment of “legal reserves” (a mandatory forest reserve on at least 20% of the land area. Conservation units are effective
    in conserving natural ecosystems. However, they are of limited value for the conservation of ecotypes, since
    their effectiveness is restricted to within their physical boundaries. Since the majority of ecotypes with critical
    adaptive value are found outside the conservation units, complementary measures to encompass these variants are needed. The most promising strategy includes active participation of rural land owners, especially small land holders, since they are settled throughout the country (outside the conservation units. An important aspect of the strategy is to prevent movement of seeds and seedlings over great distances from their origins so that their adaptive traits to specific sites are preserved.A devastação das florestas brasileiras vem tomando proporções alarmantes em todos os biomas,
    colocando muitas espécies de microorganismos, animais e plantas sob risco de extinção devido à descaracterização do habitat. Medidas governamentais contra esse processo de destruição incluem o estabelecimento de unidades de conservação e os programas de plantio de espécies nativas com objetivos variados, como a recuperação de
    ecossistemas degradados e o estabelecimento de Reservas Legais, Áreas de Proteção Permanente e outros. As unidades de

  5. 利用EcoTILLING简化技术进行水稻基因型鉴定及单核苷酸多态性(SNP)检测%Application of Simplified Ecotype Targeting Induced Local Lesions in Genomes (EcoTILLING) Technique for Genotyping and Single Nucleotide Polymorphism(SNP) Detection in Rice

    Institute of Scientific and Technical Information of China (English)

    滕斌; 李泽福; 罗志祥; 吴敬德; 朱学桂; 宣红; 张瑛

    2012-01-01

    Ecotype targeting induced local lesions in genomes (EcoTILLING) is a high-throughput method of detection and analysis of single nucleotide polymorphism (SNP) variations in natural populations. However, it requires a substantial investment in sophisticated equipment and costly fluorescence labeled primers to detect CELI - cut products that limit its use in laboratories with common financial resources. The technology of traditional EcoTILLING had been appropriately improved in this study. Here, we simplified extraction procedure of the CELI enzyme, prepared heteroduplex DNA products for CEL I digestion by use of natural cooling method, and detected the CEL I-cleaved products through general silver staining. The results of activities of crude CEL I enzyme extracts showed that the activity of CEL I was high enough for detection of mismatch bases. Using the simplified EcoTILLING technique, the G/T polymorphism at the first intron 5' splice site of the Wx gene among 18rice (Oryza saliva L.) accessions were successfully genotyped. In addition, CEL I digested bands of a 417 bp fragment within the Wx gene of the 18 rice accessions were distinguished into several types. On comparisons with sequencing results, CEL I cut bands could accurately reflect the SNP variations between the materials. The results suggested that the simplified EcoTILLING is an effective method for SNP discovery and genotyping in rice that will provide powerful tool for rice functional genomics research.%EcoTILLING(ecotype targeting induced local lesions in genomes)是一种高通量检测和分析自然群体中单核苷酸多态性(single nucleotide polymorphism,SNP)变异的研究方法.由于该技术需要高级、精密的仪器设备和昂贵的荧光标记引物来检测CEL(celery)I的酶切产物,极大地限制了该技术的应用.本研究对传统EcoTILLING技术做了适当改进,简化了CELI酶的抽提步骤,采用自然冷却方法制备异源双链产物,普通银染检测CELI酶切

  6. Killer whale morphology - Variation in morphology of killer whale ecotypes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — We are using elliptic Fourier analysis to determine the patterns of variation in morphology of dorsal fin shape, saddle patch shape, and eye patch shape of resident,...

  7. Genetic variations between two ecotypes of Egyptian clover by inter ...

    African Journals Online (AJOL)

    Aghomotsegin

    3Citrus Research and Education Center, University of Florida, IFAS, 700 Experiment Station Road, Lake Alfred, FL .... Gemmiza1 cultivars are distributed in Egypt and can give 5-6 cuts .... stem from the location of the class environment where.

  8. Standard methods for characterising subspecies and ecotypes of Apis mellifera

    DEFF Research Database (Denmark)

    Meixner, Marina D.; Pinto, Maria Alice; Bouga, Maria;

    2013-01-01

    The natural diversity of honey bees in Europe is eroding fast. A multitude of reasons lead to a loss of both genetic diversity and specific adaptations to local conditions. To preserve locally adapted bees through breeding efforts and to maintain regional strains in conservation areas, these valu...

  9. Eco-epidemiologia de Haemonchus contortus bahienses, ecotipo presente en ovinos de zonas aridas de Venezuela Eco-epidemiologia de Haemonchus contortus bahiensis, ecotipo presente em ovinos de zonas áridas da Venezuela Ecoepidemiology of Haemonchus contortus bahiensis: ecotype present in sheep of Venezuelan arid zone

    Directory of Open Access Journals (Sweden)

    Gustavo Morales

    1987-09-01

    calculated for these forms with similarities in the general size, egg-size and in the number of the longitudinal cuticular ridges. An aggregated kind of distribution in the host population according to the K parameter of a negative binomial distribution was recorded for male and female worms. A complicated interaction was observed between the abundance, aggregation and prevalence of this ecotype and the importance of these findings is discussed with regard to host-parasite relationships.

  10. Eficiência de absorção e utilização de nitrogênio por plantas de arroz e de dois ecótipos de arroz vermelho Efficiency of nitrogen uptake and utilization by rice and two red rice ecotypes

    Directory of Open Access Journals (Sweden)

    Domingos S. Eberhardt

    1999-08-01

    Full Text Available A adubação nitrogenada proporciona grandes benefícios ao arroz irrigado. No entanto, pouco se conhece sobre os seus efeitos em lavouras infestadas com plantas daninhas, especialmente com arroz vermelho, que é a espécie que causa os maiores danos à orizicultura do Rio Grande do Sul. Através de dois ensaios conduzidos em casa de vegetação e em câmara de crescimento, compararam-se as eficiências de absorção e de utilização de nitrogênio pela cv. BR-IRGA 410 com as de dois ecótipos de arroz vermelho, nos estádios de início do perfilhomento e de início do desenvolvimento da panícula. Para esta avaliação, foram utilizados estudos de cinética de absorção de nitrogênio pelas plantas em solução nutritiva e a análise de concentração e de quantidade de nitrogênio presente nas plantas. No início do perfilhomento, estádio em que a competição por luz é limitada, os três genótipos apresentam eficiências similares na absorção de nitrogênio. Adubação nitrogenada no início do desenvolvimento da panícula beneficia mais os ecótipos de arroz vermelho do que o arroz, em função da sua maior eficiência na absorção e na utilização de N.Nitrogen promotes large benefits to flooded rice. However, little is known about its effects on infested fields, especially with red rice, which is the species that causes the highest damage to flooded rice in Rio Grande do Sul, Brazil. Two experiments were conducted at greenhouse and growth chamber conditions, to compare the efficiencies of uptake and utilization of nitrogen by the cultivar BR-IRGA 410 with two red rice ecotypes, at the growth stages of initial tillering and beginning of panicle differentiation. It were used studies on kinetics of nitrogen uptake by plants in nutrient solution and the analysis of concentration and amount of nitrogen in plants. In the beginning of the tillering, stage with low competition by light, the three genotypes show similar efficiencies on

  11. Seasonal variations in the diet composition of Coilia ectenes taihuensis in different eco-types of Lake Taihu%太湖不同生态型湖区湖鲚(Coilia ectenes taihuensis)食物组成及其季节变化

    Institute of Scientific and Technical Information of China (English)

    王银平; 谷孝鸿; 曾庆飞; 毛志刚; 王文侠; 谷先坤; 李旭光

    2016-01-01

    In order to investigate the spatial and temporal diet variations of Coilia ectenes taihuensis, a special trawl and gill net were employed to sample fish in different ecotypic lakes ( open water and aquatic-type zones) of Lake Taihu from February to De-cember, 2013. In addition, feeding rate, fatness index and selectivity for different food items were examined for the purpose to study the growth and food preference of the fish. Observation of the gut contents indicated that C. ectenes taihuensis consumed a di-verse assortment of prey, such as zooplankton, fish larvae, shrimp and aquatic insects, while cladocerans and copepods were the dominant components. The diet composition of C. ectenes taihuensis varied greatly with the seasons, pelagic copepod ( mainly Cal-anoida and Cyclops) was the main prey in the winter, while pelagic cladocera (mainly Bosmina spp., Moina spp. and Chydorus spp.) was the dominant prey in the rest seasons. Compared with the two lake zones with different ecotypes, C. ectenes taihuensis in aquatic-type zone preyed more upon fish larvae, shrimp and aquatic insects and less upon copepod, while fish larvae and shrimp merely appeared in stomach of C. ectenes taihuensis with body length over 13.5 cm. The difference is obvious between the prey a-mounts of different sampling areas. 788.98±262.4 preys per fish were found in C. ectenes taihuensis stomach sampled from open wa-ter zone, while merely 298.85±71.1 preys per fish in aquatic-type zone. Feeding rates have a visible change with seasons, showing higher in the summer and winter and lower in the spring and autumn. The fish were willing to prey on large-sized cladocera, such as Daphnia cucullata, Simocephalus spp. and Daphnia magna, which the selectivity index( Ii ) fluctuated between 0.59 and 1.00. In addition, C. ectenes taihuensis showed high selectivity (0.62

  12. Comprehensive evaluation of low-temperature tolerance in soybean cultivars of different eco-types at seedling stage in Shanxi Province%山西不同生态型大豆品种苗期耐低温性综合评价

    Institute of Scientific and Technical Information of China (English)

    郭数进; 李玮瑜; 马艳芸; 赵恒; 乔玲; 李贵全

    2014-01-01

    Aims Low temperature at the seedling stage is the key factor constraining growth and yield in spring-sowing soybeans (Glycine max) in North China. The objectives of this research were to explore responses of soybean cul-tivars of different eco-types in Shanxi Province to low temperatures at the seedling stage, to develop indices and approaches for comprehensive evaluation of low-temperature tolerance in soybeans, and ultimately to provide theoretical basis for breeding soybean cultivars of low-temperature tolerance in order to maintain stable yield un-der the conditions of low temperature stress at the seedling stage. Methods We selected three soybean cultivars (‘Jinda 53’,‘Jinda 70’ and‘Jindou 24’) bred and grown widely in Shanxi Province. At the seedling stage, the plant materials were subjected to stress treatments at three levels of low temperatures and a control treatment in growth cabinets. The low temperature treatments were set for 14, 17 and 20 °C, respectively, and the control treatment was maintained at 23 °C. Upon completion of the temperature treatments, the seedlings were transplanted into larger pots and grown in a greenhouse. Values of photosynthetic traits (including net photosynthetic rates (Pn), intercellular CO2 concentration (Ci), stomatal conductance (Gs) and transpiration rate (Tr)) were determined on seedlings. The yield traits (plant height, plant mass, pods per plant and yield per plant) were assessed after harvesting. Furthermore, the genotype main effect plus genotype-environment interaction (GGE) biplot was employed to analyze the effects of various traits on different cultivars and correla-tions among the traits. Then, subordinate function was applied for comprehensive evaluation of low-temperature tolerance of the three cultivars studied. Important findings (1) The seedling stage of all three cultivars was extended by 1-12 days by the low tempera-ture treatments. (2) Values of the four photosynthetic traits were reduced

  13. Physiological and Morphological Characteristics Among Ecotypes of Basalt Milkvetch (Astragalus Filipes)

    Science.gov (United States)

    Astragalus filipes Torr. ex A. Gray (basalt milkvetch or threadstalk milkvetch) is a legume that is widely distributed in western North America and holds promise for revegetation and restoration programs in the western U.S.A. Seed of 67 accessions was collected in 2003 from Utah, Nevada, Idaho, Ore...

  14. Identification and Selection for Salt Tolerance in Alfalfa (Medicago sativa L.) Ecotypes via Physiological Traits

    OpenAIRE

    Monirifar, Hassan; Maryam BARGHI

    2009-01-01

    Salt stress is a serious environmental problem throughout the world which may be partially relieved by breeding cultivars that can tolerate salt stress. Plant breeding may provide a relatively cost effective short-term solution to the salinity problem by producing cultivars able to remain productive at low to moderate levels of salinity. Five alfalfa cultivars, �Seyah-Roud�, �Ahar-Hourand�, �Oskou�, �Malekan� and �Sefida-Khan� were assessed for salt tolerance at mature plant stage. A greenhou...

  15. Is the distribution of Prochlorococcus and Synechococcus ecotypes in the Mediterranean Sea affected by global warming?

    Directory of Open Access Journals (Sweden)

    M. Ostrowski

    2011-05-01

    Full Text Available Biological communities populating the Mediterranean Sea, which is situated at the northern boundary of the subtropics, are often claimed to be particularly affected by global warming. This is indicated, for instance, by the introduction of (subtropical species of fish or invertebrates that can displace local species. This raises the question of whether microbial communities are similarly affected, especially in the Levantine basin where sea surface temperatures have risen in recent years. In this paper, the genetic diversity of the two most abundant members of the phytoplankton community, the picocyanobacteria Prochlorococcus and Synechococcus, was examined on a transect from the South coast of France to Cyprus in the summer of 2008 (BOUM cruise. Diversity was studied using dot blot hybridization with clade-specific 16S rRNA oligonucleotide probes and clone libraries of the 16S–23S ribosomal DNA Internal Transcribed Spacer (ITS region. Data were compared with those obtained during the PROSOPE cruise held almost a decade earlier, with a focus on the abundance of clades that may constitute bioindicators of warm waters. During both cruises, the dominant Prochlorococcus clade in the upper mixed layer at all stations was HLI, a clade typical of temperate waters, whereas the HLII clade, the dominant group in (subtropical waters, was only present at very low concentrations. The Synechococcus community was dominated by clades I, III and IV in the northwestern waters of the Gulf of Lions and by clade III and groups genetically related to clades WPC1 and VI in the rest of the Mediterranean Sea. In contrast, only a few sequences of clade II, a group typical of warm waters, were observed. These data indicate that local cyanobacterial populations have not yet been displaced by their (subtropical counterparts. This is discussed in the context of the low phosphorus concentrations found in surface waters in the eastern Mediterranean basin, as this may constitute a barrier to the colonization of these waters by alien picocyanobacterial groups.

  16. Out of the Pacific and back again: the matrilineal history of Pacific killer whale ecotypes

    DEFF Research Database (Denmark)

    Foote, Andrew David; Morin, PA; JW, Durban;

    2011-01-01

    Killer whales (Orcinus orca) are the most widely distributed marine mammals and have radiated to occupy a range of ecological niches. Disparate sympatric types are found in the North Atlantic, Antarctic and North Pacific oceans, however, little is known about the underlying mechanisms driving...... reconstructions and a clinal decrease in diversity suggest a North Pacific to North Atlantic founding event, and the later return of killer whales to the North Pacific. Therefore, ecological divergence could have occurred during the allopatric phase through drift or selection and/or may have either commenced...

  17. Morphology and AFLP markers suggest three Hordeum chilense ecotypes that differ in avoidance to rust fungi

    NARCIS (Netherlands)

    Vaz Patto, M.C.; Aardse, A.; Buntjer, J.; Rubiales, D.; Martin, A.; Niks, R.E.

    2001-01-01

    In Hordeum chilense Roem. & Schult., a high variation in the level of avoidance to infection of barley leaf rust (Puccinia hordei Otth) occurs. Probably resulting from the properties of the stomata, the rust germ tube overgrows stomata, and the infection process fails in an early stage. In the prese

  18. Molecular characterization of the submergence response of Arabidopsis thaliana ecotype Columbia

    DEFF Research Database (Denmark)

    Lee, S.C.; Mustroph, A.; Sasidaharan, R.

    2011-01-01

    A detailed description of the molecular response of Arabidopsis thaliana to submergence can aid the identification of genes that are critical to flooding survival. • Rosette-stage plants were fully submerged in complete darkness and shoot and root tissue was harvested separately after the O2...

  19. Serra da Estrela Cheese: evaluation of the thistle ecotype on the physical, chemical and sensorial properties

    OpenAIRE

    Tenreiro, Marlene; Guiné, Raquel; Barracosa, Paulo; Correia, Paula; Correia, Ana Cristina

    2014-01-01

    Serra da Estrela cheese is the most famous variety of farm cheese manufactured in Portugal. Its manufacture is artisanal, from raw ewe's milk of a native breed (Bordaleira da Serra da Estrela), which is coagulated using an aqueous extract of the wild thistle (Cynara cardunculus), without deliberate addition of any starter culture [1-2]. The study of microstructure in specialty cheeses is relevant to sensory features and to fundamental explanation of the changes observed throughout cheese r...

  20. Over the falls? Rapid evolution of ecotypic differentiation in steelhead/rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Pearse, Devon E; Hayes, Sean A; Bond, Morgan H; Hanson, Chad V; Anderson, Eric C; Macfarlane, R Bruce; Garza, John Carlos

    2009-01-01

    Adaptation to novel habitats and phenotypic plasticity can be counteracting forces in evolution, but both are key characteristics of the life history of steelhead/rainbow trout (Oncorhynchus mykiss). Anadromous steelhead reproduce in freshwater river systems and small coastal streams but grow and mature in the ocean. Resident rainbow trout, either sympatric with steelhead or isolated above barrier dams or waterfalls, represent an alternative life-history form that lives entirely in freshwater. We analyzed population genetic data from 1486 anadromous and resident O. mykiss from a small stream in coastal California with multiple barrier waterfalls. Based on data from 18 highly variable microsatellite loci (He = 0.68), we conclude that the resident population above one barrier, Big Creek Falls, is the result of a recent anthropogenic introduction from the anadromous population of O. mykiss below the falls. Furthermore, fish from this above-barrier population occasionally descend over the falls and have established a genetically differentiated below-barrier subpopulation at the base of the falls, which appears to remain reproductively isolated from their now-sympatric anadromous ancestors. These results support a hypothesis of rapid evolution of a purely resident life history in the above-barrier population in response to strong selection against downstream movement.

  1. Differences in foraging ecology align with genetically divergent ecotypes of a highly mobile marine top predator.

    Science.gov (United States)

    Jeglinski, Jana W E; Wolf, Jochen B W; Werner, Christiane; Costa, Daniel P; Trillmich, Fritz

    2015-12-01

    Foraging differentiation within a species can contribute to restricted gene flow between ecologically different groups, promoting ecological speciation. Galapagos sea lions (Zalophus wollebaeki) show genetic and morphological divergence between the western and central archipelago, possibly as a result of an ecologically mediated contrast in the marine habitat. We use global positioning system (GPS) data, time-depth recordings (TDR), stable isotope and scat data to compare foraging habitat characteristics, diving behaviour and diet composition of Galapagos sea lions from a western and a central colony. We consider both juvenile and adult life stages to assess the potential role of ontogenetic shifts that can be crucial in shaping foraging behaviour and habitat choice for life. We found differences in foraging habitat use, foraging style and diet composition that aligned with genetic differentiation. These differences were consistent between juvenile and adult sea lions from the same colony, overriding age-specific behavioural differences. Our study contributes to an understanding of the complex interaction of ecological condition, plastic behavioural response and genetic make-up of interconnected populations.

  2. Researches Regarding the Morphological Characterization of the Bee Populations Belonging to Banat Ecotype

    OpenAIRE

    Silvia Pătruică; Adrian Siceanu; Eliza Căuia; Eliza Simiz; Marian Bura; Ionuţ Bănăţean Dunea; Daniela Mutu

    2010-01-01

    This work presents the results of the morphological measurements performed on working bees originating in 6 apiaries located in Caras-Severin and Timis Counties. The experiments were carried out during 15.08.2009- 15.09.2009, on 412 bees belonging to the species Apis mellifica carpatica. During the experiment, we performed the following determinations: proboscis length, anterior wing length and width, posterior wing length and width, tibia length, tarsus length and we calculated the tarsal, c...

  3. Mixing of vineyard and oak-tree ecotypes of Saccharomyces cerevisiae in North American vineyards.

    Science.gov (United States)

    Hyma, Katie E; Fay, Justin C

    2013-06-01

    Humans have had a significant impact on the distribution and abundance of Saccharomyces cerevisiae through its widespread use in beer, bread and wine production. Yet, similar to other Saccharomyces species, S. cerevisiae has also been isolated from habitats unrelated to fermentations. Strains of S. cerevisiae isolated from grapes, wine must and vineyards worldwide are genetically differentiated from strains isolated from oak-tree bark, exudate and associated soil in North America. However, the causes and consequences of this differentiation have not yet been resolved. Historical differentiation of these two groups may have been influenced by geographic, ecological or human-associated barriers to gene flow. Here, we make use of the relatively recent establishment of vineyards across North America to identify and characterize any active barriers to gene flow between these two groups. We examined S. cerevisiae strains isolated from grapes and oak trees within three North American vineyards and compared them to those isolated from oak trees outside of vineyards. Within vineyards, we found evidence of migration between grapes and oak trees and potential gene flow between the divergent oak-tree and vineyard groups. Yet, we found no vineyard genotypes on oak trees outside of vineyards. In contrast, Saccharomyces paradoxus isolated from the same sources showed population structure characterized by isolation by distance. The apparent absence of ecological or genetic barriers between sympatric vineyard and oak-tree populations of S. cerevisiae implies that vineyards play an important role in the mixing between these two groups.

  4. Phylogenetic diversity of the Bacillus pumilus group and the marine ecotype revealed by multilocus sequence analysis.

    Science.gov (United States)

    Liu, Yang; Lai, Qiliang; Dong, Chunming; Sun, Fengqin; Wang, Liping; Li, Guangyu; Shao, Zongze

    2013-01-01

    Bacteria closely related to Bacillus pumilus cannot be distinguished from such other species as B. safensis, B. stratosphericus, B. altitudinis and B. aerophilus simply by 16S rRNA gene sequence. In this report, 76 marine strains were subjected to phylogenetic analysis based on 7 housekeeping genes to understand the phylogeny and biogeography in comparison with other origins. A phylogenetic tree based on the 7 housekeeping genes concatenated in the order of gyrB-rpoB-pycA-pyrE-mutL-aroE-trpB was constructed and compared with trees based on the single genes. All these trees exhibited a similar topology structure with small variations. Our 79 strains were divided into 6 groups from A to F; Group A was the largest and contained 49 strains close to B. altitudinis. Additional two large groups were presented by B. safensis and B. pumilus respectively. Among the housekeeping genes, gyrB and pyrE showed comparatively better resolution power and may serve as molecular markers to distinguish these closely related strains. Furthermore, a recombinant phylogenetic tree based on the gyrB gene and containing 73 terrestrial and our isolates was constructed to detect the relationship between marine and other sources. The tree clearly showed that the bacteria of marine origin were clustered together in all the large groups. In contrast, the cluster belonging to B. safensis was mainly composed of bacteria of terrestrial origin. Interestingly, nearly all the marine isolates were at the top of the tree, indicating the possibility of the recent divergence of this bacterial group in marine environments. We conclude that B. altitudinis bacteria are the most widely spread of the B. pumilus group in marine environments. In summary, this report provides the first evidence regarding the systematic evolution of this bacterial group, and knowledge of their phylogenetic diversity will help in the understanding of their ecological role and distribution in marine environments.

  5. Gene Expression Differences between Noccaea caerulescens Ecotypes Help to Identify Candidate Genes for Metal Phytoremediation

    NARCIS (Netherlands)

    Halimaa, P.; Lin, Y.F.; Ahonen, V.H.; Blande, D.; Clemens, S.; Gyenesei, A.; Haikio, E.; Karenlampi, S.O.; Laiho, A.; Aarts, M.G.M.; Pursiheimo, J.P.; Schat, H.; Schmidt, H.; Tuomainen, M.H.; Tervahauta, A.I.

    2014-01-01

    Populations of Noccaea caerulescens show tremendous differences in their capacity to hyperaccumulate and hypertolerate metals. To explore the differences that could contribute to these traits, we undertook SOLiD high-throughput sequencing of the root transcriptomes of three phenotypically

  6. Is the distribution of Prochlorococcus and Synechococcus ecotypes in the Mediterranean Sea affected by global warming?

    Science.gov (United States)

    Mella-Flores, D.; Mazard, S.; Humily, F.; Partensky, F.; Mahé, F.; Bariat, L.; Courties, C.; Marie, D.; Ras, J.; Mauriac, R.; Jeanthon, C.; Mahdi Bendif, E.; Ostrowski, M.; Scanlan, D. J.; Garczarek, L.

    2011-09-01

    Biological communities populating the Mediterranean Sea, which is situated at the northern boundary of the subtropics, are often claimed to be particularly affected by global warming. This is indicated, for instance, by the introduction of (sub)tropical species of fish or invertebrates that can displace local species. This raises the question of whether microbial communities are similarly affected, especially in the Levantine basin where sea surface temperatures have significantly risen over the last 25 years (0.50 ± 0.11 °C in average per decade, P libraries of the 16S-23S ribosomal DNA Internal Transcribed Spacer (ITS) region, with a focus on the abundance of clades that may constitute bioindicators of warm waters. During both cruises, the dominant Prochlorococcus clade in the upper mixed layer at all stations was HLI, a clade typical of temperate waters, whereas the HLII clade, the dominant group in (sub)tropical waters, was only present at very low concentrations. The Synechococcus community was dominated by clades I, III and IV in the northwestern waters of the Gulf of Lions and by clade III and groups genetically related to clades WPC1 and VI in the rest of the Mediterranean Sea. In contrast, only a few sequences of clade II, a group typical of warm waters, were observed. These data indicate that local cyanobacterial populations have not yet been displaced by their (sub)tropical counterparts.

  7. Reactions of Lotus japonicus ecotypes and mutants to root parasitic plants.

    Science.gov (United States)

    Kubo, Mie; Ueda, Hiroaki; Park, Pyoyun; Kawaguchi, Masayoshi; Sugimoto, Yukihiro

    2009-03-01

    Witchweeds (Striga spp.) and broomrapes (Orobanche spp.) are obligate root parasitic plants on economically important field and horticultural crops. The parasites' seeds are induced to germinate by root-derived chemical signals. The radicular end is transformed into a haustorium which attaches, penetrates the host root and establishes connection with the vascular system of the host. Reactions of Lotus japonicus, a model legume for functional genomics, were studied for furthering the understanding of host-parasite interactions. Lotus japonicus was compatible with Orobanche aegyptiaca, but not with Orobanche minor, Striga hermonthica and Striga gesnerioides. Orobanche minor successfully penetrated Lotus japonicus roots, but failed to establish connections with the vascular system. Haustoria in Striga hermonthica attached to the roots, but penetration and subsequent growth of the endophyte in the cortex were restricted. Striga gesnerioides did not parasitize Lotus japonicus. Among seven mutants of Lotus japonicus (castor-5, har1-5, alb1-1, ccamk-3, nup85-3, nfr1-3 and nsp2-1) with altered characteristics in relation to rhizobial nodulation and mycorrhizal colonization, castor-5 and har1-5 were parasitized by Orobanche aegyptiaca with higher frequency than the wild type. In contrast, Orobanche aegyptiaca tubercle development was delayed on the mutants nup85-3, nfr1-3 and nsp2-1. These results suggest that nodulation, mycorrhizal colonization and infection by root parasitic plants in Lotus japonicus may be modulated by similar mechanisms and that Lotus japonicus is a potential model legume for studying plant-plant parasitism.

  8. Arabidopsis Ecotypes: A Model for Course Projects in Organismal Plant Biology & Evolution

    Science.gov (United States)

    Wyatt, Sarah; Ballard, Harvey E.

    2007-01-01

    We present an inquiry-based project using readily-available seed stocks of Arabidopsis. Seedlings are grown under simulated "common garden" conditions to test evolutionary and organismal principles. Students learn scientific method by developing hypotheses and selecting appropriate data and analyses for their experiments. Experiments can be…

  9. Is the distribution of Prochlorococcus and Synechococcus ecotypes in the Mediterranean Sea affected by global warming?

    Directory of Open Access Journals (Sweden)

    M. Ostrowski

    2011-09-01

    Full Text Available Biological communities populating the Mediterranean Sea, which is situated at the northern boundary of the subtropics, are often claimed to be particularly affected by global warming. This is indicated, for instance, by the introduction of (subtropical species of fish or invertebrates that can displace local species. This raises the question of whether microbial communities are similarly affected, especially in the Levantine basin where sea surface temperatures have significantly risen over the last 25 years (0.50 ± 0.11 °C in average per decade, P Prochlorococcus and Synechococcus, was examined during two cruises through both eastern and western Mediterranean Sea basins held in September 1999 (PROSOPE cruise and in June–July 2008 (BOUM cruise. Diversity was studied using dot blot hybridization with clade-specific 16S rRNA oligonucleotide probes and/or clone libraries of the 16S-23S ribosomal DNA Internal Transcribed Spacer (ITS region, with a focus on the abundance of clades that may constitute bioindicators of warm waters. During both cruises, the dominant Prochlorococcus clade in the upper mixed layer at all stations was HLI, a clade typical of temperate waters, whereas the HLII clade, the dominant group in (subtropical waters, was only present at very low concentrations. The Synechococcus community was dominated by clades I, III and IV in the northwestern waters of the Gulf of Lions and by clade III and groups genetically related to clades WPC1 and VI in the rest of the Mediterranean Sea. In contrast, only a few sequences of clade II, a group typical of warm waters, were observed. These data indicate that local cyanobacterial populations have not yet been displaced by their (subtropical counterparts.

  10. Nutritional value of Opuntia ficus-indica cladodes from Portuguese ecotypes

    OpenAIRE

    Rodrigues, A M; Pitacas, F.I.; Reis, C.G.; Blasco, M.

    2016-01-01

    The use of Opuntia ficus-indica cladodes as a forage for ruminants has been very important in the semi-arid and arid regions of the world. O. ficus-indica cladodes can be fed to small ruminants especially in periods of the year when there is low quality and quantity of pasture. In Mediterranean regions like South of Portugal during the rainy season the availability of pasture is quantitatively and qualitatively satisfactory, but in critical times of the year the shortage and low nutr...

  11. Ecotypic variation in Cystoclonium purpureum (Rhodophyta) synchronizes life history events in different regions

    NARCIS (Netherlands)

    Molenaar, F.J; Breeman, Arno; Venekamp, L.A.H.

    1996-01-01

    Temperature and daylength responses were determined in culture for isolates of the red alga Cystoclonium purpureum (Hudson) Batters from Nova Scotia (NS, Canada), Helgoland (HE, Germany), and Roscoff (RO, France). Most isolates survived temperatures of -1.5 degrees/-2 degrees to 23 degrees C, wherea

  12. Litter Decomposition Rates, 2015

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains decomposition rates for litter of Salicornia pacifica, Distichlis spicata, and Deschampsia cespitosa buried at 7 tidal marsh sites in 2015....

  13. Linear loss of litter over time, 2015

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This table contains data on dry mass remaining in a subset of Salicornia pacifica and Deschampsia cespitosa litter bags removed over a series of time points spanning...

  14. Iron deficiency-induced changes in growth reveal differences in nutrient partitioning between two ecotypes of Medicago truncatula

    Science.gov (United States)

    Enhancing the nutritional quality of crops is of international importance, and multiple methods have been utilized to increase the nutrient content of legume seeds. Because nutrients mobilized from source leaves to growing reproductive sink tissues greatly contribute to the final composition of the ...

  15. Characterization of bean (Phaseolus vulgaris L.) ecotype "Fagiolo occhio nero di Oliveto Citra" using agronomic, biochemical and molecular approaches.

    Science.gov (United States)

    Zaccardelli, Massimo; Pentangelo, Alfonso; Tripodi, Pasquale

    2013-09-15

    Common bean (Phaseolus vulgaris) is the most important grain legume and plays a significant role in human nutrition being a major source of dietary protein and representing a rich source of minerals and certain vitamins. Several large germplasm collections have been established, which contain large amounts of genetic diversity, including wild and domesticated species. In this study agronomic, biochemical and molecular characterization of landrace bean named "Fagiolo occhio nero di Oliveto Citra" (Phaseolus vulgaris L.), is described. Seeds were obtained by local farmers and field trials were carried out during years 2009-2010, in the typical cultivation site (Oliveto Citra, Salerno Province), using two different densities of investment. During 2011, in order to evaluate the performance in different environments, field trials were conducted in three localities (Battipaglia, Oliveto Citra and Controne). Data analysis shows good adaptability across locations and similar grain yield using two spacing's of seeds. Morphological characterization and molecular analysis, using AFLP and Minisatellite molecular markers, were performed on ten "biotypes" collected from local farmers. Seeds characterization showed variability on the violet area surrounding the hilum (named as eye) while markers have provided useful information on relationships between biotypes. Biochemical analysis, which includes the contents of protein, minerals and antioxidants, shows how the composition is consistent with respect to other landraces and commercial cultivars. The landrace under study revealed genetic stability and good adaptation to cultivated environment with best performance in the native area. In addition, the bio-agronomic characteristics are in accord with studies reported in literature.

  16. Effect of heat treatment and milling on the seed, flour, rheology and baking quality of some amaranth ecotypes.

    Science.gov (United States)

    Sánchez-Marroquín, A; Maya, S; Domingo, M V

    1985-12-01

    Forty-five harvests corresponding to the two predominating domestic species of amaranth in Mexico were studied. The proximate analysis revealed some statistically significant differences throughout three years of observation. The Ca, P and Fe content did not vary greatly in 15 samples. No chemical differences were either manifested in the Mercado and Aztec types of A. hypochondriacus, nor in the Mexican type of A. cruentus. The latter exhibits a higher grain yield and a shorter life cycle; however, its baking quality is apparently inferior to that of the Mercado type of A. hypochondriacus. The heat treatment of the seeds (toasting, popping and cooking) affected protein and lysine contents as does in cereals and leguminous seeds although toasting in particular improves its sensory characteristics without altering digestibility and PER. Popping only improves PER. Heating at 90 or 170 degrees C for three to five minutes, at the usual seed's moisture rate of 6 to 15%, does not affect protein content and does so only slightly in the case of the fatty acids content. Amylographic and farinographic values of the starchy fractions indicate similarities to C. quinoa and differences with respect to wheat. In the case of "amaranth milk", viscosity and gelatinization temperature produced satisfactory values. The extension of amaranth cultivation in the country is hereby suggested in view of the seed's nutritional quality, and considering the behavior of whole amaranth flour and its fractions.

  17. Postglacial climate changes and rise of three ecotypes of harbour porpoises, Phocoena phocoena, in western Palearctic waters

    NARCIS (Netherlands)

    Fontaine, Michaël C; Roland, Kathleen; Calves, Isabelle; Austerlitz, Frederic; Palstra, Friso P; Tolley, Krystal A; Ryan, Sean; Ferreira, Marisa; Jauniaux, Thierry; Llavona, Angela; Öztürk, Bayram; Öztürk, Ayaka A; Ridoux, Vincent; Rogan, Emer; Sequeira, Marina; Siebert, Ursula; Vikingsson, Gísli A; Borrell, Asunción; Michaux, Johan R; Aguilar, Alex

    2014-01-01

    Despite no obvious barriers to gene flow in the marine realm, environmental variation and ecological specializations can lead to genetic differentiation in highly mobile predators. Here, we investigated the genetic structure of the harbour porpoise over the entire species distribution range in weste

  18. Morphology and anatomy of the diaspores and seedling ofPaspalum (Poaceae, Poales)

    OpenAIRE

    EICHEMBERG,MAYRA T.; Scatena,Vera L.

    2013-01-01

    RESUMO O conhecimento relativo ao diásporo e ao desenvolvimento pós-seminal de Paspalum L. é importante para a conservação da biodiversidade dos campos, devido sua importância na representatividade e no melhoramento genético de pastagens. A morfologia do diásporo e do desenvolvimento pós-seminal de Paspalum dilatatum Poir. (rizomatosa); P. mandiocanum Trin. var. subaequiglume Barreto (estolonífera), P. pumilum Nees. (cespitosa decumbente) e P. urvillei Steud. (cespitosa ereta) foi descrita pr...

  19. No effect of seed source on multiple aspects of ecosystem functioning during ecological restoration: cultivars compared to local ecotypes of dominant grasses

    National Research Council Canada - National Science Library

    Baer, Sara G; Gibson, David J; Gustafson, Danny J; Benscoter, Allison M; Reed, Lewis K; Campbell, Ryan E; Klopf, Ryan P; Willand, Jason E; Wodika, Ben R

    2014-01-01

    Genetic principles underlie recommendations to use local seed, but a paucity of information exists on the genetic distinction and ecological consequences of using different seed sources in restorations...

  20. Differential expression of RFamide-related peptide, a mammalian gonadotrophin-inhibitory hormone orthologue, and kisspeptin in the hypothalamus of Abadeh ecotype does during breeding and anoestrous seasons.

    Science.gov (United States)

    Jafarzadeh Shirazi, M R; Zamiri, M J; Salehi, M S; Moradi, S; Tamadon, A; Namavar, M R; Akhlaghi, A; Tsutsui, K; Caraty, A

    2014-03-01

    Gonadotrophin-inhibitory hormone (GnIH) is a novel hypothalamic neuropeptide that was discovered in birds as an inhibitory factor for gonadotrophin release. RFamide-related peptide (RFRP) is a mammalian GnIH orthologue that inhibits gonadotrophin synthesis and release in mammals through actions on gonadotrophin-releasing hormone (GnRH) neurones and gonadotrophs, mediated via the GnIH receptor (GnIH-R), GPR147. On the other hand, hypothalamic kisspeptin provokes the release of GnRH from the hypothalamus. The present study aimed to compare the expression of RFRP in the dorsomedial hypothalamus and paraventricular nucleus (DMH/PVN) and that of kisspeptin in the arcuate nucleus (ARC) of the female goat hypothalamus during anoestrous and breeding seasons. Mature female Abadeh does were used during anoestrus, as well as the follicular and luteal phases of the cycle. The number of RFRP-immunoreactive (-IR) neurones in the follicular phase was lower than in the luteal and anoestrous stages. Irrespective of the ovarian stage, the number of RFRP-IR neurones in the rostral and middle regions of the DMH/PVN was higher than in the caudal region. By contrast, the number of kisspeptin-IR neurones in the follicular stage was greater than in the luteal stage and during the anoestrous stage. Irrespective of the stage of the ovarian cycle, the number of kisspeptin-IR neurones in the caudal region of the ARC was greater than in the middle and rostral regions. In conclusion, RFRP-IR cells were more abundant in the rostral region of the DMH/PVN nuclei of the hypothalamus, with a greater number being found during the luteal and anoestrous stages compared to the follicular stage. On the other hand, kisspeptin-IR neurones were more abundant in the caudal part of the ARC, with a greater number recorded in the follicular stage compared to the luteal and anoestrous stages.

  1. Analysis of Large Seeds from Three Different Medicago truncatula Ecotypes Reveals a Potential Role of Hormonal Balance in Final Size Determination of Legume Grains

    Directory of Open Access Journals (Sweden)

    Kaustav Bandyopadhyay

    2016-09-01

    Full Text Available Legume seeds are important as protein and oil source for human diet. Understanding how their final seed size is determined is crucial to improve crop yield. In this study, we analyzed seed development of three accessions of the model legume, Medicago truncatula, displaying contrasted seed size. By comparing two large seed accessions to the reference accession A17, we described mechanisms associated with large seed size determination and potential factors modulating the final seed size. We observed that early events during embryogenesis had a major impact on final seed size and a delayed heart stage embryo development resulted to large seeds. We also observed that the difference in seed growth rate was mainly due to a difference in embryo cell number, implicating a role of cell division rate. Large seed accessions could be explained by an extended period of cell division due to a longer embryogenesis phase. According to our observations and recent reports, we observed that auxin (IAA and abscisic acid (ABA ratio could be a key determinant of cell division regulation at the end of embryogenesis. Overall, our study highlights that timing of events occurring during early seed development play decisive role for final seed size determination.

  2. Structural Color Formation and Ecotype Coloration of Textiles (Ⅲ)%结构生色和纺织品生态着色(三)

    Institute of Scientific and Technical Information of China (English)

    宋心远; 沈煜如

    2005-01-01

    该文先简要介绍了自然界产生颜色的起因,介绍分析了光与纺织品的作用途径和方式;分析了选择吸收产生颜色和结构生色的特点和不同,并重点介绍了物体对光散射、干涉和衍射产生结构色的基本条件;分析了自然界一些物体结构生色的原因.文章后半部分介绍了纺织品结构生色产品,包括结构生色丝和薄膜,结构生色液晶纺织品,以及颜料、粘着剂与涂层薄膜的结构色.最后简要介绍了增深、消光、透明、反光、闪光以及珠光染整等仿生加工的原理和途径.

  3. 结构生色和纺织品生态着色(一)%Structural Color Formation and Ecotype Coloration of Textiles (Ⅰ)

    Institute of Scientific and Technical Information of China (English)

    宋心远; 沈煜如

    2005-01-01

    该文先简要介绍了自然界产生颜色的起因,介绍分析了光与纺织品的作用途径和方式;分析了选择吸收产生颜色和结构生色的特点和不同,并重点介绍了物体对光散射、干涉和衍射产生结构色的基本条件;分析了自然界一些物体结构生色的原因.文章后半部分介绍了纺织品结构生色产品,包括结构生色丝和薄膜,结构生色液晶纺织品,以及颜料、粘着剂与涂层薄膜的结构色.最后简要介绍了增深、消光、透明、反光、闪光以及珠光染整等仿生加工的原理和途径.

  4. Structural Color Formation and Ecotype Coloration of Textiles (Ⅱ)%结构生色和纺织品生态着色(二)

    Institute of Scientific and Technical Information of China (English)

    宋心远; 沈煜如

    2005-01-01

    该文先简要介绍了自然界产生颜色的起因,介绍分析了光与纺织品的作用途径和方式;分析了选择吸收产生颜色和结构生色的特点和不同,并重点介绍了物体对光散射、干涉和衍射产生结构色的基本条件;分析了自然界一些物体结构生色的原因.文章后半部分介绍了纺织品结构生色产品,包括结构生色丝和薄膜,结构生色液晶纺织品,以及颜料、粘着剂与涂层薄膜的结构色.最后简要介绍了增深、消光、透明、反光、闪光以及珠光染整等仿生加工的原理和途径.

  5. Elevated Genetic Diversity in an F2:6 Population of Quinoa (Chenopodium quinoa) Developed through an Inter-ecotype Cross

    OpenAIRE

    Benlhabib, Ouafae; Boujartani, Noura; Maughan, Peter J.; Jacobsen, Sven-Erik; Jellen, Eric N.

    2016-01-01

    Quinoa (Chenopodium quinoa) is a seed crop of the Andean highlands and Araucanian coastal regions of South America that has recently expanded in use and production beyond its native range. This is largely due to its superb nutritional value, consisting of protein that is rich in essential amino acids along with vitamins and minerals. Quinoa also presents a remarkable degree of tolerance to saline conditions, drought, and frost. The present study involved 72 F2:6 recombinant-inbred lines and p...

  6. 生态型边沟在高速公路工程中的应用研究%Application Research of Ecotype Ditches in Highway Engineering

    Institute of Scientific and Technical Information of China (English)

    鄂海清

    2016-01-01

    随着高速公路景观要求的提高,未来高速公路排水设计中,生态型边沟将是一个趋势.本文在调查、分析现有生态型边沟使用效果的基础上,结合实际工程项目,通过计算分析确定生态型边沟的断面尺寸、结构型式和使用条件,为生态型边沟在高速公路项目中的使用推广提供借鉴.

  7. 聚焦ISO 14001标准创建生态旅游岛%Focus on ISO 14001 Standard, Found Tourist Island of Ecotype

    Institute of Scientific and Technical Information of China (English)

    薛东辉; 洪华生

    2001-01-01

    With the practice of implementing ISO 14001 standard in Gulangyu District, the significance and process and characteristics of implementing ISO 14001 standard were discussed. It provides experience for beauty spots establishing system of environmental management.%结合鼓浪屿区实施ISO 14001标准,探讨了其意义、实施步骤和特点,可为其它风景名胜区建立环境管理体系所借鉴。

  8. Study On The Ecotype Heat- preservation And Energy -saving Wall%关于生态型保温节能墙体的研究

    Institute of Scientific and Technical Information of China (English)

    刘学强

    2012-01-01

    Application of heat - preservation and energy - saving wall increased with the increasing of dwelling construction, especially in the north cold district. The reduction of energy resource makes it important for energy - saying. There are many techniques and methods of heat - preservation and energy - saving and the development of thermal insulation material greatly improve the heat - preservation effect. This paper states the wall heat - preservation and energy -saving technique and material application.%住宅建筑日益增多,保温节能在墙体上的应用也随之增大,尤其在我国北方寒冷地区的墙体保温更是不可缺少的。能源的减少使节能也越来越受到关注;现代住宅建筑既要保温又要节省能源,就我国来说节能保温的技术方法很多,保温材料的技术发展使得保温节能的效果得到了很大的提升,本文主要论述了墙体的保温节能技术和材料应用。

  9. 绿色生态环保建筑材料的LCA评价方法%The LCA evaluating method of the green ecotypic health-care materials

    Institute of Scientific and Technical Information of China (English)

    彭亦博; 张雄

    2006-01-01

    生命周期评价(Life Cycle Assessment),简称LCA,又称为寿命。它包括材料的整个过程:从自然资源,经过加工成为材料,供人类使用之后,又回到自然这样一个封闭的流动过程。此过程被形象地描述为从“摇篮”到“坟墓”的过程(见图1)。它的出现,标志着人类开始了对产品、包装材料、一次性使用物品等产品全寿命周期中的资源、能源、环境排放物、废物再生利用等进行量化处理,并以此来评判产品的环境协调性。这个方法就是目前的环境负荷编目LCI(Life cycle Inventory)法。

  10. Growth and metal accumulation of an Alyssum murale nickel hyperaccumulator ecotype co-cropped with Alyssum montanum or perennial ryegrass in serpentine soil

    Science.gov (United States)

    More than 400 plant species naturally accumulate high levels of metals such as Cd, Cu, Co, Mn, Ni, and Zn. The genus Alyssum (Brassicaceae) contains the greatest number of reported Ni hyperaccumulators (50), many of which can achieve 3 wt% Ni in dry leaves. Some Alyssum hyperaccumulators are viabl...

  11. Cyanobacterial ecotypes in different optical microenvironments of a 68 C hot spring mat community revealed by 16S-23S rRNA internal transcribed spacer region variation

    DEFF Research Database (Denmark)

    Ferris, Mike J.; Kühl, Michael; Wieland, Andrea

    2003-01-01

    We examined the population of unicellular cyanobacteria (Synechococcus) in the upper 3-mm vertical interval of a 68°C region of a microbial mat in a hot spring effluent channel (Yellowstone National Park, Wyoming). Fluorescence microscopy and microsensor measurements of O2 and oxygenic photosynth......We examined the population of unicellular cyanobacteria (Synechococcus) in the upper 3-mm vertical interval of a 68°C region of a microbial mat in a hot spring effluent channel (Yellowstone National Park, Wyoming). Fluorescence microscopy and microsensor measurements of O2 and oxygenic...... distinct populations over the vertical interval. We were unable to identify patterns in genetic variation in Synechococcus 16S rRNA sequences that correlate with different vertically distributed populations. However, patterns of variation at the internal transcribed spacer locus separating 16S and 23S r...

  12. Elevated genetic diversity in an F2:6 population of quinoa (Chenopodium quinoa) developed through an inter-ecotype cross

    DEFF Research Database (Denmark)

    Benlhabib, Ouafae; Boujartani, Noura; Maughan, Peter J

    2016-01-01

    . The purpose was to characterize the quinoa germplasm developed, to assess the discriminating potential of 21 agro-morpho-phenological traits, and to evaluate the extent of genetic variability recovered through selfing. A vast amount of genetic variation was detected among the 72 lines evaluated......, and resistance to downy mildew. In the Principal Component analysis, the first axis explained 74% of the total variation and was correlated to plant height, panicle size, stem diameter, biomass, mildew reaction, maturation, and seed yield; those traits are relevant discriminatory characters. Yield correlated...

  13. The molecular dimension of microbial species: 1. Ecological distinctions among, and homogeneity within, putative ecotypes of Synechococcus inhabiting the cyanobacterial mat of Mushroom Spring, Yellowstone National Park

    DEFF Research Database (Denmark)

    Becraft, Eric D.; Wood, Jason M.; Rusch, Douglas B.;

    2015-01-01

    -defined positions in the effluent channel and vertical position in the upper 1 mm-thick mat layer. Importantly, in most cases variants predicted to belong to the same PE formed unique clusters relative to temperature and depth in the mat in canonical correspondence analysis, supporting the hypothesis that while...

  14. Reproductive biology of the Amazon Lava Lizard (Tropidurus torquatus) from the Wet Chaco of Corrientes (Argentina): congeneric comparisons of ecotypic and interspecific variations

    National Research Council Canada - National Science Library

    Ortiz, M.A; Boretto, J.M; Piantoni, C; Alvarez, B.B; Ibarguengoytia, N.R

    2014-01-01

    ... of T. torquatus and congeneric species. In Corrientes, males of T. torquatus exhibited a continuous reproductive cycle, but with annual variation of testicular parameters associated with spermatogenic activity...

  15. Growth and Metal Accumulation of an Alyssum murale Nickel Hyperaccumulator Ecotype Co-cropped with Alyssum montanum and Perennial Ryegrass in Serpentine Soil

    Directory of Open Access Journals (Sweden)

    Catherine Leigh Broadhurst

    2016-04-01

    Full Text Available The genus Alyssum (Brassicaceae contains Ni hyperaccumulators (50, many of which can achieve 30 g kg-1 Ni in dry leaf. Some Alyssum hyperaccumulators are viable candidates for commercial Ni phytoremediation and phytomining technologies. It is not known whether these species secrete organic and/or amino acids into the rhizosphere to solubilize Ni, or can make use of such acids within the soil to facilitate uptake. It has been hypothesized that in fields with mixed plant species, mobilization of metals by phytosiderophores secreted by Graminaceae plants could affect Alyssum Ni, Fe, Cu and Mn uptake.We co-cropped the Ni hyperaccumulator Alyssum murale, non-hyperaccumulator A. montanum and perennial ryegrass in a natural serpentine soil. All treatments had standard inorganic fertilization required for ryegrass growth and one treatment was compost amended. After 4 months A. murale leaves and stems contained 3600 mg kg-1 Ni which did not differ significantly with co-cropping. Overall Ni and Mn concentrations were significantly higher in A. murale than in A. montanum or L. perenne. Copper was not accumulated by either Alyssum species, but L. perenne accumulated up to 10 mg kg-1. A. montanum could not compete with either A. murale or ryegrass, and neither Alyssum species survived in the compost-amended soil. Co-cropping with ryegrass reduced Fe and Mn concentrations in A. murale but not to the extent of either increasing Ni uptake or affecting plant nutrition. The hypothesized Alyssum Ni accumulation in response to phytosiderophores secreted by co-cropped grass did not occur. Our data do not support increased mobilization of Mn by a phytosiderophore mechanism either, but the converse: mobilization of Mn by the Alyssum hyperaccumulator species significantly increased Mn levels in L. perenne. Tilling soil to maximize root penetration, adequate inorganic fertilization and appropriate plant densities are more important for developing efficient phytoremediation and phytomining approaches.

  16. Elevated genetic diversity in an F2:6 population of quinoa (Chenopodium quinoa developed through an inter-ecotype cross

    Directory of Open Access Journals (Sweden)

    Ouafae Benlhabib

    2016-08-01

    Full Text Available Quinoa (Chenopodium quinoa is a seed crop of the Andean highlands and Araucanian coastal regions of South America that has recently expanded in use and production beyond its native range. This is largely due its superb nutritional value, consisting of protein that is rich in essential amino acids along with vitamins and minerals. Quinoa also presents a remarkable degree of tolerance to saline conditions, drought, and frost. The present study involved 72 F2:6 recombinant inbred lines (RIL and parents developed through hybridization between highland (0654 and coastal (NL-6 germplasm groups. The purpose was to characterize the quinoa germplasm developed, to assess the discriminating potential of 21 agro-morpho phenological traits, and to evaluate the extent of genetic variability recovered through selfing. A vast amount of genetic variation was detected among the 72 lines evaluated for quantitative and qualitative traits. Impressive transgressive segregation was measured for seed yield (22.42 g/plant, while plant height and maturity had higher heritabilities (73 and 89%, respectively. Other notable characters segregating in the population included panicle and stem color, panicle form, and resistance to downy mildew. In the Principal Component analysis, the first axis explained 74% of the total variation and was correlated to plant height, panicle size, stem diameter, biomass, mildew reaction, maturation, and seed yield; those traits are relevant discriminatory characters. Yield correlated positively with panicle length and biomass. UPGMA based cluster analysis identified three groups: one consisting of late, mildew-resistant, high yielding lines; one having semi-late lines with intermediate yield and mildew susceptibility; and a third cluster consisting of early to semi-late accessions with low yield and mildew susceptibility. This study highlighted the extended diversity regenerated among the 72 accessions and helped to identify potentially adapted quinoa genotypes for production in the Moroccan coastal environment.

  17. Elevated Genetic Diversity in an F2:6 Population of Quinoa (Chenopodium quinoa) Developed through an Inter-ecotype Cross.

    Science.gov (United States)

    Benlhabib, Ouafae; Boujartani, Noura; Maughan, Peter J; Jacobsen, Sven E; Jellen, Eric N

    2016-01-01

    Quinoa (Chenopodium quinoa) is a seed crop of the Andean highlands and Araucanian coastal regions of South America that has recently expanded in use and production beyond its native range. This is largely due to its superb nutritional value, consisting of protein that is rich in essential amino acids along with vitamins and minerals. Quinoa also presents a remarkable degree of tolerance to saline conditions, drought, and frost. The present study involved 72 F2:6 recombinant-inbred lines and parents developed through hybridization between highland (0654) and coastal (NL-6) germplasm groups. The purpose was to characterize the quinoa germplasm developed, to assess the discriminating potential of 21 agro-morpho-phenological traits, and to evaluate the extent of genetic variability recovered through selfing. A vast amount of genetic variation was detected among the 72 lines evaluated for quantitative and qualitative traits. Impressive transgressive segregation was measured for seed yield (22.42 g/plant), while plant height and maturity had higher heritabilities (73 and 89%, respectively). Other notable characters segregating in the population included panicle and stem color, panicle form, and resistance to downy mildew. In the Principal Component analysis, the first axis explained 74% of the total variation and was correlated to plant height, panicle size, stem diameter, biomass, mildew reaction, maturation, and seed yield; those traits are relevant discriminatory characters. Yield correlated positively with panicle length and biomass. Unweighted Pair Group Method with Arithmetic Mean-based cluster analysis identified three groups: one consisting of late, mildew-resistant, high-yielding lines; one having semi-late lines with intermediate yield and mildew susceptibility; and a third cluster consisting of early to semi-late accessions with low yield and mildew susceptibility. This study highlighted the extended diversity regenerated among the 72 accessions and helped to identify potentially adapted quinoa genotypes for production in the Moroccan coastal environment.

  18. Analysis of Large Seeds from Three Different Medicago truncatula Ecotypes Reveals a Potential Role of Hormonal Balance in Final Size Determination of Legume Grains

    Science.gov (United States)

    Bandyopadhyay, Kaustav; Uluçay, Orhan; Şakiroğlu, Muhammet; Udvardi, Michael K.; Verdier, Jerome

    2016-01-01

    Legume seeds are important as protein and oil source for human diet. Understanding how their final seed size is determined is crucial to improve crop yield. In this study, we analyzed seed development of three accessions of the model legume, Medicago truncatula, displaying contrasted seed size. By comparing two large seed accessions to the reference accession A17, we described mechanisms associated with large seed size determination and potential factors modulating the final seed size. We observed that early events during embryogenesis had a major impact on final seed size and a delayed heart stage embryo development resulted to large seeds. We also observed that the difference in seed growth rate was mainly due to a difference in embryo cell number, implicating a role of cell division rate. Large seed accessions could be explained by an extended period of cell division due to a longer embryogenesis phase. According to our observations and recent reports, we observed that auxin (IAA) and abscisic acid (ABA) ratio could be a key determinant of cell division regulation at the end of embryogenesis. Overall, our study highlights that timing of events occurring during early seed development play decisive role for final seed size determination. PMID:27618017

  19. Planning and Design for Eco-Sustainable Farmland Consolidation

    Institute of Scientific and Technical Information of China (English)

    BAO Hai-Jun; WU Yu-Zhe; WU Ci-Fang; XU Bao-Gen

    2005-01-01

    With a view of sustainable development, different kinds of farmland consolidation are reviewed. A planning and design mode for eco-sustainable farmland consolidation, which integrated the ecotypic board, the ecotypic tunnel, the ecotypic island, and the ecotypic boundary, is proposed. Then, an actual case of farmland consolidation, a project located in Yinzhou County, Zhejiang Province, is used to demonstrate the effective application procedures of the planning and design mode.

  20. Wetlands Research Program. Corps of Engineers Wetlands Delineation Manual. Appendix C. Sections 1 and 2. Region 4 - North Plains.

    Science.gov (United States)

    1987-01-01

    Mountain bladderfern Danthonia intexrnedia Vasey Timber danthonia FAC I eschampsia cespitosa (L.) Beauv. Tufted hairgrass FACW 2’. eiongata (Hook...Munro Slender hairgrass FACW Eichanthelium acuminatum (Swartz) Gould Pacific panicum FAC DRA & C. A. Clarke istichZis spicata (L.) Greene Seashore...King & Joe-pyeweed FACW+ Boneset OBL ,c" :. ;reene Bushy golden-rod FACW \\utt. Grass -leaved goldenrod FACW -,ut. Goldenrod OBL Red fescue FAC ""(L

  1. Reconnaissance Observations of Long-Term Natural Vegetation Recovery in the Cape Thompson Region, Alaska, and Additions to the Checklist of Flora,

    Science.gov (United States)

    1985-06-01

    sp. A few individuals of Deschampsia traria islandica, C. nivalis, Cladonia sp., Parmelia cespitosa are also present; this plant becomes omphalodes...primary taxon; it was also record- lata, C. nivalis, Cladonia amaurocraea, Lobaria ed on the runway sites. Other mosses include Bar- tramia ithyphylla...Nyl. Krog 1962 as S. wrightii flaeomycetaceae Baeomyces roseus Pers. Johnson et al. 1966 Cladoniaceae Cladina rangiferina (L.) Harm. Johnson et al

  2. Discussion on Development Mechanism of Sheep Production of Grassland Ecotype Livestock Industry in Qinghai Province%青海省草地生态畜牧业中养羊业发展机制探讨

    Institute of Scientific and Technical Information of China (English)

    刘迎春; Whistler R J M; 邹华; 岳炳辉; 杨予海; 邸平胜; 刘妍妍

    2016-01-01

    在草地生态畜牧业战略总体规划下,养羊产业仍然是青海省草地畜牧业的主要组成部分.该研究分析了青海省养羊业现状,指出当地可以进一步降低羊总数,提高个体生产力,加速周转.通过分析产业内部因素和外部环境条件,提出产业发展思路:在建立牧民合作组织的基础上,开展集约化、规模化和标准化生产经营,应用配套技术,推广科技成果,牧民学习新技术,提高生产、管理和营销能力.

  3. Phenological and Phenotypic Differences and Correlations among Ecotypes of Hordeum spontaneum Originating from Different Locations in Israel%以色列野生二棱大麦农艺性状差异及相关性分析

    Institute of Scientific and Technical Information of China (English)

    严俊; 程剑平; Y. Gutterman; E. Nevo

    2007-01-01

    为给野生大麦的遗传和基因资源的研究提供依据,对起源于以色列不同地区6个群体的16个生态型野生二棱大麦的物候性状进行了研究.结果表明,不同生态型间的物候性状差异明显.从个体水平上分析,其最大值均出现在湿生生态型中,除旗叶面积外,其最小值则出现在旱生生态型中;从群体水平上分析,除每穗粒数外,湿生型平均值皆高于旱生型平均值.曼-怀氏等级和检验显示,湿生型和旱生型之间的这些物候性状差异达到显著水平.斯皮尔曼秩相关性检验则表明,9个物候与性状间,除三叶期与粒重、穗粒重无相关性外,其余物候性状间均呈显著的相关性,其中生长期与旗叶面积、株高、穗长、芒长等呈显著正相关,与每穗粒数则呈显著负相关;芒长与旗叶面积、株高,稳长与株高存在显著正相关,而每穗粒数则与芒长和旗叶面积分别呈显著负相关,芒长与穗长亦呈显著正相关.分析表明,以色列不同地区野生大麦物候性状差异是其生境主导下生存选择的结果,其丰富的表现型多样性,可用于遗传与育种研究.

  4. 不同生态型复播油葵生育规律的研究%A preliminary study on growth characteristics of different ecotyp es of oil sunflower in multiple cropping system

    Institute of Scientific and Technical Information of China (English)

    张凤华; 朱志新; 丁天云; 马晓娥; 赖先齐

    2002-01-01

    按生育期的不同将新疆北疆沿天山一带复种油葵品种分为3种生态型,分析其生育特性,结果表明:晚熟型品种在叶片生长特点、群体冠层结构及 同化物运转等方面均优于早熟型及中熟型品种,但由于在灌浆中后期气温过低,造成灌浆不 充分,制约其高产潜力的发挥,从而表现为低产.故鉴于当地气候条件,复播油葵应选用早 熟型品种,但需采取相应的栽培措施,以利于建立合理的群体结构及提高籽粒充实程度.

  5. Complexation and toxicity of copper in higher plants. II. Different mechanisms for copper versus cadmium detoxification in the copper-sensitive cadmium/zinc hyperaccumulator Thlaspi caerulescens (Ganges Ecotype).

    Science.gov (United States)

    Mijovilovich, Ana; Leitenmaier, Barbara; Meyer-Klaucke, Wolfram; Kroneck, Peter M H; Götz, Birgit; Küpper, Hendrik

    2009-10-01

    The cadmium/zinc hyperaccumulator Thlaspi caerulescens is sensitive toward copper (Cu) toxicity, which is a problem for phytoremediation of soils with mixed contamination. Cu levels in T. caerulescens grown with 10 microm Cu(2+) remained in the nonaccumulator range (hyperaccumulation and metal resistance are highly metal specific. Cu-induced inhibition of photosynthesis followed the "sun reaction" type of damage, with inhibition of the photosystem II reaction center charge separation and the water-splitting complex. A few individuals of T. caerulescens were more Cu resistant. Compared with Cu-sensitive individuals, they recovered faster from inhibition, at least partially by enhanced repair of chlorophyll-protein complexes but not by exclusion, since the content of Cu in their shoots was increased by about 25%. Extended x-ray absorption fine structure (EXAFS) measurements on frozen-hydrated leaf samples revealed that a large proportion of Cu in T. caerulescens is bound by sulfur ligands. This is in contrast to the known binding environment of cadmium and zinc in the same species, which is dominated by oxygen ligands. Clearly, hyperaccumulators detoxify hyperaccumulated metals differently compared with nonaccumulated metals. Furthermore, strong features in the Cu-EXAFS spectra ascribed to metal-metal contributions were found, in particular in the Cu-resistant specimens. Some of these features may be due to Cu binding to metallothioneins, but a larger proportion seems to result from biomineralization, most likely Cu(II) oxalate and Cu(II) oxides. Additional contributions in the EXAFS spectra indicate complexation of Cu(II) by the nonproteogenic amino acid nicotianamine, which has a very high affinity for Cu(II) as further characterized here.

  6. 核雄性不育基因向卵圆生态型大白菜中的成功转育%Successfully Transferring Genic Male Sterile Line to Ovate Ecotype Chinese Cabbage

    Institute of Scientific and Technical Information of China (English)

    岳艳玲; 冯辉

    2005-01-01

    本研究根据"复等位基因遗传假说",以甲型"两用系"AB21为不育源(直筒生态型),采用杂交、自交、兄妹交的方法,将核不育基因向卵圆生态型大白菜可育品系Lu6-11中转育,获得了不育株率100%的卵圆生态型大白菜核基因雄性不育系.扩大了原有不育系的遗传基础,拓宽了该优良雄性不育基因的应用范围.

  7. 不同生态区8种芸芥根系生物量的初步研究%Study on root system biomass of different ecotypes of Eruca Sativa Mill

    Institute of Scientific and Technical Information of China (English)

    王鹤龄; 牛俊义; 孙万仓; 杨瑞吉; 曾秀存; 盖玥

    2005-01-01

    通过管栽模拟试验,研究了不同生态区8个芸芥类型(高抗旱类型的会宁芸芥、陇西芸芥,中抗旱类型的张北芸芥、Varomin芸芥、兴和芸芥、和田芸芥,低抗旱类型的西凉芸芥、四川芸芥)的根系生长情况.结果表明:芸芥根系生物量的垂直层次分布模型可用多项式y=a+bx+cx2+dx3描述;会宁、陇西、兴和、西凉芸芥与张北、和田、Varomin、四川芸芥的各参数值(a、b、c、d)总体相差较大且根系总生物量、各层次的生物量和根/冠比前者均低于后者;各层次根系生物量的百分含量也呈现不同的垂直变化规律.无论是总的还是各层次的根系生物量,强抗旱芸芥类型的趋于中等大小,中抗芸芥类型的有大也有小,低抗芸芥类型的均较大.

  8. Assessing the regulation of leaf redox status under water stress conditions in Arabidopsis thaliana: Col-0 ecotype (wild-type and vtc-2), expressing mitochondrial and cytosolic roGFP1.

    Science.gov (United States)

    Brossa, Ricard; Pintó-Marijuan, Marta; Jiang, Keni; Alegre, Leonor; Feldman, Lewis J

    2013-07-01

    Using Arabidopsis plants Col-0 and vtc2 transformed with a redox sensitive green fluorescent protein, (c-roGFP) and (m-roGFP), we investigated the effects of a progressive water stress and re-watering on the redox status of the cytosol and the mitochondria. Our results establish that water stress affects redox status differently in these two compartments, depending on phenotype and leaf age, furthermore we conclude that ascorbate plays a pivotal role in mediating redox status homeostasis and that Col-0 Arabidopsis subjected to water stress increase the synthesis of ascorbate suggesting that ascorbate may play a role in buffering changes in redox status in the mitochondria and the cytosol, with the presumed buffering capacity of ascorbate being more noticeable in young compared with mature leaves. Re-watering of water-stressed plants was paralleled by a return of both the redox status and ascorbate to the levels of well-watered plants. In contrast to the effects of water stress on ascorbate levels, there were no significant changes in the levels of glutathione, thereby suggesting that the regeneration and increase in ascorbate in water-stressed plants may occur by other processes in addition to the regeneration of ascorbate via the glutathione. Under water stress in vtc2 lines it was observed stronger differences in redox status in relation to leaf age, than due to water stress conditions compared with Col-0 plants. In the vtc2 an increase in DHA was observed in water-stressed plants. Furthermore, this work confirms the accuracy and sensitivity of the roGFP1 biosensor as a reporter for variations in water stress-associated changes in redox potentials.

  9. Outlier loci detect intraspecific biodiversity amongst spring and autumn spawning herring across local scales

    DEFF Research Database (Denmark)

    Bekkevold, Dorte; Gross, Riho; Arula, Timo

    2016-01-01

    analyses reveal clear genetic differences between ecotypes and hence support reproductive isolation. Loci showing non-neutral behaviour, so-called outlier loci, show convergence between autumn spawning herring from demographically disjoint populations, potentially reflecting selective processes associated...... with autumn spawning ecotypes. The abundance and exploitation of the two ecotypes have varied strongly over space and time in the Baltic Sea, where autumn spawners have faced strong depression for decades. The results therefore have practical implications by highlighting the need for specific management...

  10. An evolutionary and functional genomics study of Noccaea caerulescens, a heavy metal hyperaccumulating plant species

    OpenAIRE

    Wang, Y.

    2016-01-01

    Noccaea caerulescens is the only known Zn/Cd/Ni hyperaccumulator. The Ganges accession (2n = 14) has an, yet unpublished, genome size of ~319 Mb, with 29,712 predicted genes representing 15,874 gene families. This species is distributed mainly in Europe. Three ecotypes can be distinguished: two metallicolous ecotypes, resident to serpentine soil (Ni enriched) and calamine soil (Zn/Cd enriched), and a non-metallicolous ecotype, growing on regular, non-metalliferous soils. The physiological dif...

  11. Comparative molecular cytogenetic characterization of seven Deschampsia (Poaceae) species.

    Science.gov (United States)

    Amosova, Alexandra V; Bolsheva, Nadezhda L; Zoshchuk, Svyatoslav A; Twardovska, Maryana O; Yurkevich, Olga Yu; Andreev, Igor O; Samatadze, Tatiana E; Badaeva, Ekaterina D; Kunakh, Viktor A; Muravenko, Olga V

    2017-01-01

    The genus Deschampsia P. Beauv (Poaceae) involves a group of widespread polymorphic species. Some of them are highly tolerant to stressful and variable environmental conditions, and D. antarctica is one of the only two vascular plants growing in Antarctic. This species is a source of useful for selection traits and a valuable model for studying an environmental stress tolerance in plants. Genome diversity and comparative chromosomal phylogeny within the genus have not been studied yet as karyotypes of most Deschampsia species are poorly investigated. We firstly conducted a comparative molecular cytogenetic analysis of D. antarctica (Antarctic Peninsula) and related species from various localities (D. cespitosa, D. danthonioides, D. elongata, D. flexuosa (= Avenella flexuosa), D. parvula and D. sukatschewii by fluorescence in situ hybridization with 45S and 5S rDNA, DAPI-banding and sequential rapid in situ hybridization with genomic DNA of D. antarctica, D. cespitosa, and D. flexuosa. Based on patterns of distribution of the examined markers, chromosomes of the studied species were identified. Within these species, common features as well as species peculiarities in their karyotypic structure and chromosomal distribution of molecular cytogenetic markers were characterized. Different chromosomal rearrangements were detected in D. antarctica, D. flexuosa, D. elongata and D. sukatschewii. In karyotypes of D. antarctica, D. cespitosa, D. elongata and D. sukatschewii, 0-3 B chromosomes possessed distinct DAPI-bands were observed. Our findings suggest that the genome evolution of the genus Deschampsia involved polyploidy and also different chromosomal rearrangements. The obtained results will help clarify the relationships within the genus Deschampsia, and can be a basis for the further genetic and biotechnological studies as well as for selection of plants tolerant to extreme habitats.

  12. Diversity and population structure of northern switchgrass as revealed though exome capture sequencing

    Science.gov (United States)

    Switchgrass (Panicum virgatum L.) is a polyploid, perennial grass species that is native to North America, and is being developed as a future biofuels feedstock crop. Switchgrass is present primarily in two ecotypes: a northern upland ecotype composed of tetraploid and octoploid accessions, and a so...

  13. 78 FR 47277 - Listing Endangered or Threatened Species: 12-Month Finding on a Petition To Delist the Southern...

    Science.gov (United States)

    2013-08-05

    ... ecotypes of whales overlap in the northeastern Pacific Ocean, available genetic data indicate that there is...). The lines of evidence supporting differentiation between the ecotypes of North Pacific whales are... populations as defined by the 1996 DPS policy, citing significant genetic differentiation, separate...

  14. Complete mitochondrial genome phylogeographic analysis of killer whales (Orcinus orca) indicates multiple species

    DEFF Research Database (Denmark)

    Morin, Phillip A; Archer, Frederick I.; Foote, Andrew David

    2010-01-01

    Killer whales (Orcinus orca) currently comprise a single, cosmopolitan species with a diverse diet. However, studies over the last 30 yr have revealed populations of sympatric "ecotypes" with discrete prey preferences, morphology, and behaviors. Although these ecotypes avoid social interactions a...

  15. Experimental evolution of an emerging plant virus in host genotypes that differ in their susceptibility to infection.

    Science.gov (United States)

    Hillung, Julia; Cuevas, José M; Valverde, Sergi; Elena, Santiago F

    2014-09-01

    This study evaluates the extent to which genetic differences among host individuals from the same species condition the evolution of a plant RNA virus. We performed a threefold replicated evolution experiment in which Tobacco etch potyvirus isolate At17b (TEV-At17b), adapted to Arabidopsis thaliana ecotype Ler-0, was serially passaged in five genetically heterogeneous ecotypes of A. thaliana. After 15 passages we found that evolved viruses improved their fitness, showed higher infectivity and stronger virulence in their local host ecotypes. The genome of evolved lineages was sequenced and putative adaptive mutations identified. Host-driven convergent mutations have been identified. Evidences supported selection for increased translational efficiency. Next, we sought for the specificity of virus adaptation by infecting all five ecotypes with all 15 evolved virus populations. We found that some ecotypes were more permissive to infection than others, and that some evolved virus isolates were more specialist/generalist than others. The bipartite network linking ecotypes with evolved viruses was significantly nested but not modular, suggesting that hard-to-infect ecotypes were infected by generalist viruses whereas easy-to-infect ecotypes were infected by all viruses, as predicted by a gene-for-gene model of infection.

  16. PENINGKATAN KANDUNGAN MINYAK ATSIRI TEMULAWAK SEBAGAI BAHAN BAKU OBAT Pengujian Peningkatan Kandungan Minyak Atsiri Temulawak pada Berbagai Ekotipe dan Kondisi Intensitas Cahaya Matahari yang Berbeda

    Directory of Open Access Journals (Sweden)

    Kasiran Kasiran

    2012-11-01

    Full Text Available Background: One of the important substance in the Javanese turmeric was essential oil (atsiri. The essential oil of Javanese turmeric was very useful for human health and medical industries. Efforts to increase the content of essential oil in Javanese turmeric tuber will give and increase usage of Javanese turmeric for medical industries. Objective: The research is to test the level of essential oil of Javanese turmeric in the several ecotypes which cultivate in the different condition of sunshine intensity. Methods: The analysis of essential oil was held by using 10 g of Javanese turmeric sample powder through destilation method. Results: The research show that the different of ecotype of Javanese turmeric will give significant effects on the essential oli content in the tubers. Whereas, the interaction between sunshine intensity and ecotype including interaction of both factors did not have significant effects. The highes essential oil content was in the ecotype from Sleman (T9 that was 6.46% and ecotype Manna (T3 that was 6.37%. Whereas, the lowest essential oil content was in the ecotype from Bawang Village, Kulon Progo (T13, that was 2.96%. Therefore, the ecotype selection of Javanese turmeric wich will be cultivated was important in order to get high essential oil content. Key words: Essential oli, javanese turmeric, ecotype, sunshine intensity

  17. Intraspecific variation of a dominant grass and local adaptation in reciprocal garden communities along a US Great Plains' precipitation gradient: implications for grassland restoration with climate change.

    Science.gov (United States)

    Johnson, Loretta C; Olsen, Jacob T; Tetreault, Hannah; DeLaCruz, Angel; Bryant, Johnny; Morgan, Theodore J; Knapp, Mary; Bello, Nora M; Baer, Sara G; Maricle, Brian R

    2015-08-01

    Identifying suitable genetic stock for restoration often employs a 'best guess' approach. Without adaptive variation studies, restoration may be misguided. We test the extent to which climate in central US grasslands exerts selection pressure on a foundation grass big bluestem (Andropogon gerardii), widely used in restorations, and resulting in local adaptation. We seeded three regional ecotypes of A. gerardii in reciprocal transplant garden communities across 1150 km precipitation gradient. We measured ecological responses over several timescales (instantaneous gas exchange, medium-term chlorophyll absorbance, and long-term responses of establishment and cover) in response to climate and biotic factors and tested if ecotypes could expand range. The ecotype from the driest region exhibited greatest cover under low rainfall, suggesting local adaptation under abiotic stress. Unexpectedly, no evidence for cover differences between ecotypes exists at mesic sites where establishment and cover of all ecotypes were low, perhaps due to strong biotic pressures. Expression of adaptive differences is strongly environment specific. Given observed adaptive variation, the most conservative restoration strategy would be to plant the local ecotype, especially in drier locations. With superior performance of the most xeric ecotype under dry conditions and predicted drought, this ecotype may migrate eastward, naturally or with assistance in restorations.

  18. Studies upon morhological and biological traits of Festuca rubra, subsp.fallax (Poaceae

    Directory of Open Access Journals (Sweden)

    Bogusław Sawicki

    2013-12-01

    Full Text Available Observation and measurements of some traits of Festuca rubra L., subsp. fallax (Thuill. Hack. ecotypes were made in 1995-1997 using samples selected from natural habitats and collected in Grassland Experimental Station in Sosnowica. High differentiation of traits under study and their correlations were found. Valorized ecotypes are good material for new varieties breeding.

  19. Metabolite profiling of Arabidopsis thaliana (L.) plants transformed with an antisense chalcone synthase gene

    DEFF Research Database (Denmark)

    Le Gall, G.; Metzdorff, Stine Broeng; Pedersen, Jan W.;

    2005-01-01

    A metabolite profiling study has been carried out on Arabidopsis thaliana (L.) Heynh. ecotype Wassilewskija and a series of transgenic lines of the ecotype transformed with a CHS (chalcone synthase) antisense construct. Compound identifications by LC/MS and H-1 NMR are discussed. The glucosinolate...

  20. NCBI nr-aa BLAST: CBRC-TTRU-01-0453 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-TTRU-01-0453 ref|YP_002125639.1| hypothetical protein MADE_01331 [Alteromonas macleodii 'Deep... ecotype'] gb|ACG65645.1| hypothetical protein MADE_01331 [Alteromonas macleodii 'Deep ecotype'] YP_002125639.1 0.20 24% ...

  1. NCBI nr-aa BLAST: CBRC-GGAL-15-0007 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-GGAL-15-0007 ref|ZP_01109341.1| gamma-glutamyltranspeptidase [Alteromonas macleodii 'Deep... ecotype'] gb|EAR06392.1| gamma-glutamyltranspeptidase [Alteromonas macleodii 'Deep ecotype'] ZP_01109341.1 0.39 31% ...

  2. NCBI nr-aa BLAST: CBRC-CREM-01-1371 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-CREM-01-1371 ref|ZP_01109498.1| phosphopyruvate hydratase [Alteromonas macleodii 'Deep... ecotype'] gb|EAR06202.1| phosphopyruvate hydratase [Alteromonas macleodii 'Deep ecotype'] ZP_01109498.1 2e-88 70% ...

  3. Naturally evolved enhanced Cd tolerance of Dianthus carthusianorum L. is not related to accumulation of thiol peptides and organic acids.

    Science.gov (United States)

    Wójcik, Małgorzata; Dresler, Sławomir; Plak, Andrzej; Tukiendorf, Anna

    2015-05-01

    Two contrasting ecotypes of Dianthus carthusianorum L., metallicolous (M) and nonmetallicolous (NM), were cultivated in hydroponics at 0-50 μM Cd for 14 days to compare their Cd accumulation, sensitivity and tolerance mechanisms. While both ecotypes contained similar concentrations of Cd in the shoots and roots, the M ecotype was more Cd-tolerant (as measured by fresh weight production and root and leaf viability). Both ecotypes accumulated phytochelatins (PCs) in response to Cd with a higher amount thereof found in the NM ecotype. Concentrations of PCs remained unchanged with increasing Cd concentrations in the root tissues, but their content in the shoots increased. The addition of L-buthionine-sulfoximine (BSO) diminished glutathione (GSH) accumulation and arrested PC production, which increased the sensitivity to Cd of the NM, but not M ecotype. Organic acids (malate and citrate) as well as proline accumulation did not change significantly after Cd exposition and was at the same level in both ecotypes. The enhanced Cd tolerance of the M ecotype of D. carthusianorum cannot be explained in terms of restricted Cd uptake and differential production of PCs, organic acids or proline; some other mechanisms must be involved in its adaptation to the high Cd content in the environment.

  4. 云南新平花腰傣新型土掌房材料建构的审美价值及策略思考%The Aesthetic Value and Building Strategy of Materials Used in the New Ecotype Folk House of Huayao Dai Nationality in Xinping, Yunnan

    Institute of Scientific and Technical Information of China (English)

    郭晶; 崔龙雨; 徐钊

    2016-01-01

    从云南新平花腰傣传统土掌房的建筑特色入手,分析土掌房因社会发展和时代变迁所产生的现实问题,提出通过乡土材料建构和民族文化传承来挖掘新型土掌房的审美价值,探讨其材料属性和建构策略,为新型土掌房的文脉传承和可持续发展提供多元化的理论支持。%Starting from the architectural characteristics of Tu-zhang-fang (the eo-type folk house), of Huayao Dai Nationality in Xinping, Yunnan Province, this paper offers an analysis of the realistic problems of Tu-zhang-fang resulting from the social development and time changes, and proposes to exploit the aesthetic value of the new type Tu-zhang-fang by means of the construction of local materials and inheritance of national culture. It also investigates the material attributes and building strategy to provide diversified theories for both the cultural inheritance and sustainable development of new Tu-zhang-fang.

  5. FRUTOS DE UCHUVA (PHYSALIS PERUVIANA L. ECOTIPO ‘COLOMBIA’ MÍNIMAMENTE PROCESADOS, ADICIONADOS CON MICROORGANISMOS PROBIÓTICOS UTILIZANDO LA INGENIERÍA DE MATRICES MINIMALLY PROCESSED CAPE GOOSEBERRY FRUITS (PHYSALIS PERUVIANA L. ‘COLOMBIAN’ ECOTYPE, ADDED WITH PROBIOTIC MICROORGANISMS USING THE MATRIX ENGINEERING

    Directory of Open Access Journals (Sweden)

    Zaira Tatiana Marin Arango

    2010-06-01

    Full Text Available El consumo de alimentos con microorganismos probióticos se ha incrementado en los últimos años debido a los beneficios saludables que estos proporcionan. El desarrollo de nuevos alimentos con probióticos diferentes a los productos lácteos, representa un reto para los investigadores y la industria. El presente estudio desarrolló a nivel piloto frutos de uchuva (Physalis peruviana L. mínimamente procesados con microorganismos probióticos, combinando el efecto benéfico de la cepa comercial Lactobacillus casei ATCC 393 con la aplicación de la Ingeniería de Matrices como metodología de obtención de alimentos funcionales. Se utiliza como líquido de impregnación una solución de glucosa al 14% p/p, con concentración inicial de inóculo de 5 en la escala de McFarland (1,5 x 109 UFC/mL. Las uchuvas recién impregnadas alcanzaron conteos de células viables de 1,95 ± 0,28 x 10(9 UFC/100 g de uchuva fresca (9,28 ± 0,06 x 109 ciclos log UFC/100 g uchuva fresca y a los 15 días de almacenamiento a 4 ºC los conteos de células viables fueron de 2,20 ± 0,59 x 10(9 UFC/100 g de uchuva fresca. (9,32 ± 0,14 x 109 ciclos log UFC/100 g uchuva fresca. Estos niveles de concentración de microorganismos probióticos en la uchuva son similares a los encontrados en los productos lácteos, como el yogurt, helados, quesos, entre otros.Food consumption with probiotic microorganisms has been increased in the last years due to its healthy benefits that they provide. The development of new food with probiotics apart from dairy products represents a challenge for both researchers and industry. The present study developed at pilot level cape gooseberry fruits (Physalis peruviana L. minimally processed with microorganisms probiotics, combining the beneficent effect of the strain commercial Lactobacillus casei ATCC 393 with the application of the matrix Engineering as methodology to obtain functional foods. As liquid of impregnation a solution of glucose at 14% p/p was used, with an initial concentration of inoculum of 5 in McFarland scale (1.5 x 109 UFC/mL. The newly impregnated cape gooseberry reached counts of viable cells of 1.95 ± 0.28 x 10(9 UFC/100 g of fresh cape gooseberry (9.28 ± 0.06 x 109 cycles log UFC/100 g fresh cape gooseberry and after 15 days of storage at 4 ºC counts of viable cells were of 2.20 ± 0.59 x 10(9 UFC/100 g of fresh cape gooseberry (9.32 ± 0.14 x 109 cycles log UFC/100g fresh cape gooseberry. These level of probiotic microorganisms concentration in the cape gooseberry, were similar to those found in the dairy products as the yogurt, ice creams, cheeses, among others.

  6. 河西走廊有机生态型无土栽培在设施蔬菜辣椒生产中的应用%Application of organic ecotype soilless culturing in greenhouse vegetable production of capsicum annuum in Hexi Corridor

    Institute of Scientific and Technical Information of China (English)

    郭治; 丁亮

    2016-01-01

    A completely randomized design was implemented to investigate the effects of organic cultural substrate compositions on the growth ,yield and fruit quality of Capsicum annuum in sunlight greenhouse with treatments including mushroom residue (A ) ,mushroom residue ,peat and corn stalks (B ) ,mushroom residue ,corn stalks and cinder (C ) , perlite and cinder (D) ,Vpeat∶Vcinder =3∶2 (CK1 ) as the control for soilless cultural substrate ,and soil cultivation (CK2 ) as the control for cultivation mode .The results indicated that the treatment B (mushroom residue ,peat and corn stalks) on the growth of C .annuum was the best among all treatments ,which significantly increased the plant height by 16 .6% and 11 .0% ,stem diameter by 24 .2% and 18 .8% ,fruit-setting number per plant by 5 .8 and 3 .6 ,yield per plant by 0 .67 kg and 0 .31 kg ,and plot yield by 9 .4 kg and 7 .2 kg ,from CK1 and CK2 respectively .Additionally ,the effect of treatment C (mushroom residue ,corn stalks and cinder) was the second-best ,which significantly increased the plant height by 19 .6% and 24 .5% ,and plot yield by 6 .0 kg .and 3 .8 kg ,from CK1 and CK2 respectively .Moreover , the treatments of B and C significantly improved the fruit quality of C .annuum ,and the treatment B significantly in-creased the Vc content by 48 .5% and 13 .5% ,soluble protein content by 23 .3% and 10 .9% ,and reducing suger con-tent by 27 .7% and 12 .2% , and the treatment C significantly increased the organic acid content by 16 .4% and 10 .6% ,and soluble saccharide content by 14 .3% and 10 .0% ,from CK1 and CK2 respectively .The results showed that the treatments of mushroom residue ,peat and corn stalks (B ) ,and mushroom residue ,corn stalks and cinder (C ) significantly promoted the growth of C .annuum and improved its fruits quality ,which may be suitable for popularization and application in culturing greenhouse solanaceous vegetables .%试验采用完全随机区组设计,设置处理A:纯菇渣,处理B:菇渣、泥炭土和玉米秆混合,处理C:菇渣、玉米秆和炉渣混合,处理D:珍珠岩和炉渣混合,CK1:V泥炭∶V炉渣=3∶2作为无土栽培基质对照,CK2:土壤栽培作为栽培方式对照,探讨了日光温室不同有机栽培基质配比对辣椒生长发育、产量及品质的影响。结果表明:有机基质配比处理B(菇渣、泥炭土和玉米秆混合)对辣椒的栽培效果最好,其株高、茎粗、单株结果数、单株产量及小区产量与CK1和CK2相比分别增加了16.6%和11.0%,24.2%和18.8%,5.8和3.6个,0.67kg和0.31kg,9.4kg和7.2 kg;处理C (菇渣、玉米秆和炉渣混合)对辣椒的栽培效果次之,其株高和小区产量与CK1和CK2相比分别增加了19.6%和24.5%,6.0kg和3.8kg。此外,处理B和C显著改善了辣椒果实的品质。与CK1和CK2相比,处理B辣椒果实Vc、可溶性蛋白及还原糖含量分别提高了48.5%和13.5%,23.3%和10.9%,27.7%和12.2%;处理C辣椒果实有机酸和可溶性糖类分别提高16.4%和10.6%,14.3%和10.0%。以上结果表明,有机栽培基质配比菇渣、泥炭土和玉米秆和菇渣、玉米秆和炉渣显著促进了辣椒的生长发育并且改善了果实品质,适宜在设施蔬菜茄果类作物栽培中推广应用。

  7. 大白菜细胞核雄性不育基因向卵圆型大白菜'60'的转育%Introgression of genic male sterile gene of Chinese cabbage into ovate ecotype Chinese cabbage variety '60'

    Institute of Scientific and Technical Information of China (English)

    关雪松; 许明

    2009-01-01

    根据大白菜复等位基因遗传假说,运用合成转育模式将大白菜'189'细胞核雄性不育基因转入基因型为msms的卵圆型白菜'160'中,获得了卵圆型白菜'160'的新甲型'两用系'及相应的不育系和保持系.%Based on the Multiple Allele Hypothesis of genie male sterility, the synthesis transferring method was used to transfer the gene of male sterility into the orbicular-ovate type Chinese cabbage variety '160', whose genotypes were msms by crossing, inbreeding, sibling and test crossing. New AB lines type I,new male sterile lines and their corresponding temporary maintainer lines of Chinese cabbage variety '160' were obtained from the transferred progenies of the Chinese cabbage variety '189'.

  8. Studies on genetic diversity and phylogeny of slow-growing rhizobia isolated from Vigna radiata at main ecotypes of China%我国主要生态区域绿豆慢生根瘤菌的遗传多样性和系统发育研究

    Institute of Scientific and Technical Information of China (English)

    袁天英; 杨江科; 张伟涛; 周俊初

    2006-01-01

    利用16S rRNA PCR-RFLP、16S rRNA序列分析以及16S-23S rRNA IGS (Intergenetic Spacer) PCR-RFLP技术对分离自中国主要生态区域的44株慢生型绿豆根瘤菌和5株参比菌株进行了遗传多样性和系统发育研究.16S rRNA PCR-RFLP分析表明:在76%的相似水平上,所有供试菌株可分为三大类群:群I由LYG1等13株慢生根瘤菌组成,该群在系统发育上与B. japonicum和B. liaoningense的参比菌株存在一定的差异;群Ⅱ由XJ1等21株供试菌株、B. japonicum和B.liaoningense的代表菌株组成;群Ⅲ由10株来自广东和广西的菌株和B. elkanii的代表菌株组成.16S-23S rRNA IGS PCR-RFLP分析将供试菌株分为A、B两大群.群A由34株供试菌株、B. japonicum和B.liaoningense的代表菌株组成.在85%的相似性水平上,可再分为AⅠ、AⅡ和AⅢ 3个亚群.群B由10株分离自广西和广东的菌株和B. elkanii的代表菌株组成.在85%的相似性水平上,可再分为BI和BⅡ两亚群,表现出一定的多样性.与16S rRNA PCR-RFLP相比,16S-23S rRNA IGS PCR-RFLP具有更高的解析度,供试菌株表现出更加丰富的遗传多样性.分离自中国新疆、广东和广西等地的菌株在分群上具有较为明显的地域特征.

  9. Eco-epidemiologia de Haemonchus contortus bahienses, ecotipo presente en ovinos de zonas aridas de Venezuela Eco-epidemiologia de Haemonchus contortus bahiensis, ecotipo presente em ovinos de zonas áridas da Venezuela Ecoepidemiology of Haemonchus contortus bahiensis: ecotype present in sheep of Venezuelan arid zone

    OpenAIRE

    Gustavo Morales; Pino,Luz A.

    1987-01-01

    Haemonchus contortus bahiensis Grisi, 1974 parasita a los ovinos de zonas áridas de Venezuela. En las hembras de dicho ecotipo la distribución de frecuencias por nosotros observada fue de un 15,32% para el morfotipo con lengüeta supravulvar, de un 51,61% para el botonado y de un 33,07% para el liso. Correspondiéndole a dicho ecotipo un índice de diversidad de Shannon-Weaver de 1,44 bits. Las medidas corporales, el tamaño de los huevos y el symlophe son similares en los tres morfotipos. La dis...

  10. Association of LEI0258 microsatellite alleles with antibody response ...

    African Journals Online (AJOL)

    SERVER

    2008-03-18

    Mar 18, 2008 ... vaccine and body weight in two Tanzania chicken ecotypes ... protection of the chickens from the disease. Improving disease ... from drier parts of north west Tanzania, and another representing ..... Congress, Instabul, Turkey.

  11. Identification of a locus in Arabidopsis controlling both the expression of rhizobacteria-mediated induced systemic resistance (ISR) and basal resistance against Pseudomonas syringae pv. tomato

    NARCIS (Netherlands)

    Ton, J.; Pieterse, C.M.J.; Loon, L.C. van

    1999-01-01

    Selected nonpathogenic rhizobacteria with biological disease control activity are able to elicit an induced systemic resistance (ISR) response that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Ten ecotypes of Arabidopsis thaliana were screened for their potential

  12. Isolation of microsatellite markers for Bletilla striata and cross ...

    African Journals Online (AJOL)

    esiri

    distinguish different ecotypes and species, and might be used for other subspecies or species in genera Bletilla. ... out cultivation in North American and European areas ... extension of 72°C for 5 min and then were enriched for microsatel-.

  13. Walnut Creek National Wildlife 1993 planting strategy

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The following is a summary of seed and ecotypes of seed available for planting on WNT, as well as development of planting and subsequent management strategies:

  14. Comunidades de palmas en América

    DEFF Research Database (Denmark)

    Balslev, Henrik

    2011-01-01

    .3 ± 11.3 DE especies. Los principales factores que determinan la riqueza de especies en las comunidades son el clima, los suelos, la hidrología y la topografía. Los bosques tropicales lluviosos de tierras bajas no-inundados son los más ricos en especies, en tanto que los bosques que se inundan o que...... crecen en suelos arenosos o en zonas con climas estacionales tienen mucho menos especies. Las 789 especies de palmas de América tropical pertenecen al modelo de Corner (cespitosas, 268 especies, 33%) o el modelo de Tomlinson (solitarias, 521 especies, 66%) para el patrón de ramificación. Asignamos las...

  15. Forma de crecimiento en Leptochloa Chloridiformis (Poaceae

    Directory of Open Access Journals (Sweden)

    Mariel G. Perreta

    2000-01-01

    Full Text Available Perreta, M. G., Tivano, J. C. & Vegetti, A. C. 2000. Forma de crecimiento en Leptochloachloridiformis (Poaceae. Darwiniana 38(3-4: 219-226.El objetivo de este trabajo fue analizar la forma de crecimiento de Leptochloa chloridiformis (Hack.Parodi. En esta especie perenne la ramificación ocurre principalmente a través de yemas axilarespresentes en la zona de innovación. Este sistema de ramificación genera una planta cespitosa, en la cual lasconexiones entre unidades estructurales son rizomas cortos. Dependiendo de su posición estas conexio-nes muestran diferentes tendencias en relación a la desarticulación estructural. En algunas plantas seobservó ramificación en la zona de entrenudos largos posiblemente debido a cambios ambientalesrelacionados con las distintas estaciones

  16. High-Diversity Genes in the Arabidopsis Genome

    OpenAIRE

    Cork, Jennifer M.; Purugganan, Michael D.

    2005-01-01

    High-diversity genes represent an important class of loci in organismal genomes. Since elevated levels of nucleotide variation are a key component of the molecular signature for balancing selection or local adaptation, high-diversity genes may represent loci whose alleles are selectively maintained as balanced polymorphisms. Comparison of 4300 random shotgun sequence fragments of the Arabidopsis thaliana Ler ecotype genome with the whole genomic sequence of the Col-0 ecotype identified 60 gen...

  17. JPRS Report China

    Science.gov (United States)

    2007-11-02

    Xinjiang [Zhang Pingquan; NONGYE JINGJl WENTI, 23 Oct 87] 72 Analysis of Ecotypes of Wild Soybean (G. Soja ) in China [Xu Bao, ct at.; ZIIONGGUO NONGYE...should be suitably limited. 12986 Analysis of Ecotypes of Wild Soybean (G. Soja ) in China 40110011 Beijing ZHONGGUO NONGYE KEXUE [SCIENTIA...of Agricultural Sciences, Gongzhuling, Jilin] [Text] In 1981-1985, the photo-thermo effects on the development of wild soybean (G. soja Sieb, et

  18. Root growth, mycorrhization and physiological effects of plants growing on oil tailing sands

    Science.gov (United States)

    Boldt-Burisch, Katja M.; Naeth, Anne M.; Schneider, Bernd Uwe; Hüttl, Reinhard F.

    2015-04-01

    Surface mining creates large, intense disturbances of soils and produces large volumes of by-products and waste materials. After mining processes these materials often provide the basis for land reclamation and ecosystem restoration. In the present study, tailing sands (TS) and processed mature fine tailings (pMFT) from Fort McMurray (Alberta, Canada) were used. They represent challenging material for ecosystem rebuilding because of very low nutrient contents of TS and oil residuals, high density of MFT material. In this context, little is known about the interactions of pure TS, respectively mixtures of TS and MFT and root growth, mycorrhization and plant physiological effects. Four herbaceous plant species (Elymus trachycaulus, Koeleria macrantha, Deschampsia cespitosa, Lotus corniculatus) were chosen to investigate root development, chlorophyll fluorescence and mycorrhization intensity with and without application of Glomus mosseae (arbuscular mycorrhizae) on mainly tailing sands. Surprisingly both, plants growing on pure TS and plants growing on TS with additional AM-application showed mycorrhization of roots. In general, the mycorrhization intensity was lower for plants growing on pure tailings sands, but it is an interesting fact that there is a potential for mycorrhization available in tailing sands. The mycorrhizal intensity strongly increased with application of G. mosseae for K. macrantha and L. corniculatus and even more for E. trachycaulus. For D. cespitosa similar high mycorrhiza infection frequency was found for both variants, with and without AM-application. By the application of G. mosseae, root growth of E. trachycaulus and K. macrantha was significantly positively influenced. Analysis of leaf chlorophyll fluorescence showed no significant differences for E. trachycaulus but significant positive influence of mycorrhizal application on the physiological status of L. corniculatus. However, this effect could not be detected when TS was mixed with MFT

  19. MOBILITY OF HEAVY METALS IN PLANTS AND SOIL: A CASE STUDY FROM A MINING REGION IN CANADA

    Directory of Open Access Journals (Sweden)

    M. Mehes-Smith

    2013-01-01

    Full Text Available Understanding the dynamic of metals in soil and plantsis essential for ecosystem management and risks assessment of environmental pollution and sustainability.The main objective of the present study is to determine the mobility of Ni, Cu, Fe, Mg and Zn in soil and their translocation in D. cespitosa plants in a mining region in Northern Ontario.The total amount of Cu, Ni, Fe, Mg and Zn were significantly higher in the top horizon (LFH compared to the adjacent layer Ae. The vertical distribution of metals in soil varied with the type of metals. The results of this study indicated that only a small portion of total metal was bioavailable to plants. The enrichment factor values for the targeted elements were far above the value of contamination resulting in high availability and distribution of metals in soil. The average bioconcentration/bioaccumulation factors (metal concentration ratio of plant roots to soil was high and varied from 3.1 to 40 for Cu, 24.5 to 91.6 for Fe, 18.2 to 398.6 for Mg, 10.3 to 75.5 for Ni and 24.9 to 73 for Zn. The translocation factor values were very low for the five metals. They ranged from 0.05 to 0.46 for Cu, 0.03 to 0.1 for Fe, 0.28 to 1.48 for Mg, 0.15 to 0.38 for Ni and 0.68 to 1.16 for Zn. Based on existing classification, Deschampsia. cespitosa is an excluder as it has high levels of metals in the roots but with a shoot/root ratio less than 1. This plant has a high potential for phytoextraction of metals from Northern Ontario soils.

  20. Defending the leaf surface: intra- and inter-specific differences in silicon deposition in grasses in response to damage and silicon supply

    Directory of Open Access Journals (Sweden)

    Sue Elaine Hartley

    2015-02-01

    Full Text Available Understanding interactions between grasses and their herbivores is central to the conservation of species-rich grasslands and the protection of our most important crops against pests. Grasses employ a range of defenses against their natural enemies; silicon-based defenses have been shown to be one of the most effective. Silicon (Si is laid down on the leaf surface as spines and other sharp bodies, known as phytoliths, making grasses abrasive and their foliage indigestible to herbivores. Previous studies on Si defenses found that closely related species may have similar levels of Si in the leaves but differ markedly in abrasiveness. Here we show how the number, shape and distribution of Si-rich phytoliths and spines differ within and between different grass species and demonstrate that species also differ in their ability to change the deposition and distribution of these defenses in response to damage or increases in Si supply. Specifically, we tested the response of two genotypes of Festuca arundinacea known to differ in their surface texture and 3 different grass species (F. ovina, F. rubra and Deschampsia cespitosa differing in their abrasiveness to combined manipulation of leaf damage and Si supply. F.arundinacea plants with a harsh leaf surface had higher Si content and more spines on their leaf surface than soft varieties. F. ovina and D. cespitosa plants increased their leaf Si concentration and produced an increase in the number of leaf spines and phytoliths on the leaf surface in response to Si addition. F rubra also increased leaf Si content in response to treatments, particularly in damaged leaves, but did not deposit this in the form of spines or increased densities of phytoliths. We discuss how the form in which grasses deposit Si may affect their anti-herbivore characteristics and consider the ecological and agricultural implications of the differences in allocation to Si-based defenses between grass species.

  1. Defending the leaf surface: intra- and inter-specific differences in silicon deposition in grasses in response to damage and silicon supply.

    Science.gov (United States)

    Hartley, Sue E; Fitt, Rob N; McLarnon, Emma L; Wade, Ruth N

    2015-01-01

    Understanding interactions between grasses and their herbivores is central to the conservation of species-rich grasslands and the protection of our most important crops against pests. Grasses employ a range of defenses against their natural enemies; silicon-based defenses have been shown to be one of the most effective. Silicon (Si) is laid down on the leaf surface as spines and other sharp bodies, known as phytoliths, making grasses abrasive and their foliage indigestible to herbivores. Previous studies on Si defenses found that closely related species may have similar levels of Si in the leaves but differ markedly in abrasiveness. Here we show how the number, shape and distribution of Si-rich phytoliths and spines differ within and between different grass species and demonstrate that species also differ in their ability to change the deposition and distribution of these defenses in response to damage or increases in Si supply. Specifically, we tested the response of two genotypes of Festuca arundinacea known to differ in their surface texture and three different grass species (F. ovina, F. rubra, and Deschampsia cespitosa) differing in their abrasiveness to combined manipulation of leaf damage and Si supply. F. arundinacea plants with a harsh leaf surface had higher Si content and more spines on their leaf surface than soft varieties. F. ovina and D. cespitosa plants increased their leaf Si concentration and produced an increase in the number of leaf spines and phytoliths on the leaf surface in response to Si addition. F rubra also increased leaf Si content in response to treatments, particularly in damaged leaves, but did not deposit this in the form of spines or increased densities of phytoliths. We discuss how the form in which grasses deposit Si may affect their anti-herbivore characteristics and consider the ecological and agricultural implications of the differences in allocation to Si-based defenses between grass species.

  2. Phylogeny and population structure of brown rot- and Moko disease-causing strains of Ralstonia solanacearum phylotype II.

    Science.gov (United States)

    Cellier, G; Remenant, B; Chiroleu, F; Lefeuvre, P; Prior, P

    2012-04-01

    The ancient soilborne plant vascular pathogen Ralstonia solanacearum has evolved and adapted to cause severe damage in an unusually wide range of plants. In order to better describe and understand these adaptations, strains with very similar lifestyles and host specializations are grouped into ecotypes. We used comparative genomic hybridization (CGH) to investigate three particular ecotypes in the American phylotype II group: (i) brown rot strains from phylotypes IIB-1 and IIB-2, historically known as race 3 biovar 2 and clonal; (ii) new pathogenic variants from phylotype IIB-4NPB that lack pathogenicity for banana but can infect many other plant species; and (iii) Moko disease-causing strains from phylotypes IIB-3, IIB-4, and IIA-6, historically known as race 2, that cause wilt on banana, plantain, and Heliconia spp. We compared the genomes of 72 R. solanacearum strains, mainly from the three major ecotypes of phylotype II, using a newly developed pangenomic microarray to decipher their population structure and gain clues about the epidemiology of these ecotypes. Strain phylogeny and population structure were reconstructed. The results revealed a phylogeographic structure within brown rot strains, allowing us to distinguish European outbreak strains of Andean and African origins. The pangenomic CGH data also demonstrated that Moko ecotype IIB-4 is phylogenetically distinct from the emerging IIB-4NPB strains. These findings improved our understanding of the epidemiology of important ecotypes in phylotype II and will be useful for evolutionary analyses and the development of new DNA-based diagnostic tools.

  3. Niche partitioning and biogeography of high light adapted Prochlorococcus across taxonomic ranks in the North Pacific.

    Science.gov (United States)

    Larkin, Alyse A; Blinebry, Sara K; Howes, Caroline; Lin, Yajuan; Loftus, Sarah E; Schmaus, Carrie A; Zinser, Erik R; Johnson, Zackary I

    2016-07-01

    The distribution of major clades of Prochlorococcus tracks light, temperature and other environmental variables; yet, the drivers of genomic diversity within these ecotypes and the net effect on biodiversity of the larger community are poorly understood. We examined high light (HL) adapted Prochlorococcus communities across spatial and temporal environmental gradients in the Pacific Ocean to determine the ecological drivers of population structure and diversity across taxonomic ranks. We show that the Prochlorococcus community has the highest diversity at low latitudes, but seasonality driven by temperature, day length and nutrients adds complexity. At finer taxonomic resolution, some 'sub-ecotype' clades have unique, cohesive responses to environmental variables and distinct biogeographies, suggesting that presently defined ecotypes can be further partitioned into ecologically meaningful units. Intriguingly, biogeographies of the HL-I sub-ecotypes are driven by unique combinations of environmental traits, rather than through trait hierarchy, while the HL-II sub-ecotypes appear ecologically similar, thus demonstrating differences among these dominant HL ecotypes. Examining biodiversity across taxonomic ranks reveals high-resolution dynamics of Prochlorococcus evolution and ecology that are masked at phylogenetically coarse resolution. Spatial and seasonal trends of Prochlorococcus communities suggest that the future ocean may be comprised of different populations, with implications for ecosystem structure and function.

  4. Comparing geographical genetic differentiation between candidate and noncandidate loci for adaptation strengthens support for parallel ecological divergence in the marine snail Littorina saxatilis.

    Science.gov (United States)

    Galindo, J; Morán, P; Rolán-Alvarez, E

    2009-03-01

    The Galician sympatric ecotypes of Littorina saxatilis have been proposed as a model system for studying parallel ecological speciation. Such a model system makes a clear prediction: candidate loci (for divergent adaptation) should present a higher level of geographical differentiation than noncandidate (neutral) loci. We used 2356 amplified fragment length polymorphisms (AFLPs) and four microsatellite loci to identify candidate loci for ecological adaptation using the F(ST) outlier method. Three per cent of the studied AFLP loci were identified as candidate loci associated with adaptation, after multitest adjustments, thus contributing to ecotype differentiation (candidate loci were not detected within ecotypes). Candidate and noncandidate loci were analysed separately at four different F(ST) partitions: differences between ecotypes (overall and local), differences between localities and micro-geographical differences within ecotypes. The magnitude of F(ST) differed between candidate and noncandidate loci for all partitions except in the case of micro-geographical differentiation within ecotypes, and the microsatellites (putatively neutral) showed an identical pattern to noncandidate loci. Thus, variation in candidate loci is determined partially independent by divergent natural selection (in addition to stochastic forces) at each locality, while noncandidate loci are exclusively driven by stochastic forces. These results support the evolutionary history described for these particular populations, considered to be a clear example of incomplete sympatric ecological speciation.

  5. [Distribution of the genetic diversity of the Siberian stone pine, Pinus sibirica Du Tour, along the latitudinal and longitudinal profiles].

    Science.gov (United States)

    Petrova, E A; Goroshkevich, S N; Belokon', M M; Belokon', Iu S; Politov, D V

    2014-05-01

    The Siberian stone pine (Pinus sibirica Du Tour) is one of the main forest-forming coniferous species of the boreal ecosystems of Western Siberia. We used the isozyme method to analyze 11 ecotypes representing the latitudinal and longitudinal profiles within the species range, including samples from the geographic boundaries of the distribution. The genetic structure of the ecotypes is described on the basis of the variability for 26 isozyme loci encoding for 16 enzyme systems. The greatest genetic diversity was observed in the taiga ecotypes in the central part of the studied area, while the ecotypes along the species range boundaries were shown to be genetically depauperized. Approximately 8.1% of the observed genetic diversity is attributed to differences between the studied ecotypes. We detected high levels of genetic diversity for the Fest_2, Pgm_1, Sod_4, and a few otherloci, as well as a correlation between allele frequencies and geographical locations of the populations. The results of multivariate analysis of allelic frequencies as well as cluster analysis allowed us to discriminate three major groups of ecotypes: north-eastern, central and south-western. In view of our results, we compare two hypotheses: one which attributes the spatial distribution of genetic variations to the selectivity for some of the polymorphic allozyme loci, and the other based in the history of the formation of the range of the Siberian stone pine.

  6. Variability of needle structure in Siberian stone pine in provenance plantations

    Directory of Open Access Journals (Sweden)

    O. Bender

    2013-12-01

    Full Text Available Siberian stone pine (Pinus sibirica Du Tour is one of the most common trees in Siberia. Its natural range is from the Ural Mountains to the Aldan river and from the Arctic Circle to northern Mongolia. The climate in natural Siberian stone pine sites influences the whole plant organism, particularly its needle structure, and the response to thisoccurs at specific morphological and anatomical levels. The genotypical and environmental effects on needle structure in different Siberianstone pine ecotypes are very little known. One effective way to examine and to separate genotypical effects from environmental ones is byusing a common garden experiment. The purpose is to analyze morphological and anatomical needle variability in Siberian stone pinemarginal populations that have been grown in provenance plantations in southern West Siberia, Russia. The needle samples were collectedin the provenance plantation located 30 km south of Tomsk (the southeastern West Siberian Plain, southern limit of the taiga zone,optimum site conditions for Siberian stone pine. We investigated the grafts of mother trees taken from natural sites. Four ecotypeswere selected for the study. Three ecotypes originated from northern (Urengoy, western (Neviyansk, and eastern (Severobaikalskmarginal populations. The fourth, the Tomsk ecotype, was a local control. The local Tomsk ecotype grows on a site where natural conditions are worse due to reduction of mean annual temperature and increase of the humid factor northward, humidity reduction eastward and its rise westward. Variability of 10 needle morphologicaland anatomical characteristics was studied. The northern ecotype had smaller needle length (28%, leaf cross-section area (21%, mesophyll area (29%, mesophyll cell size (27%, and conducting bundle area (16% but the number of stomata per unit leaf area increased by 16% over the local Tomsk ecotype. The resin canal area, epidermal andhypodermal

  7. Morphological and physiological responses of lowland purple nutsedge (Cyperus rotundus L.) to flooding

    Science.gov (United States)

    Fuentes, Rolly G.; Baltazar, Aurora M.; Merca, Florinia E.; Ismail, Abdelbagi M.; Johnson, David E.

    2010-01-01

    Background and aims Purple nutsedge (Cyperus rotundus L.) is a major weed of upland crops and vegetables. Recently, a flood-tolerant ecotype evolved as a serious weed in lowland rice. This study attempted to establish the putative growth and physiological features that led to this shift in adaptation. Methodology Tubers of upland C. rotundus (ULCR) and lowland C. rotundus (LLCR) ecotypes were collected from their native habitats and maintained under the respective growth conditions in a greenhouse. Five experiments were conducted to assess the variation between the two ecotypes in germination, growth and tuber morphology when grown in their native or ‘switched’ conditions. Carbohydrate storage and mobilization, and variation in anaerobic respiration under hypoxia were compared. Principal results Tubers of LLCR were larger than those of ULCR, with higher carbohydrate content, and larger tubers developed with increasing floodwater depth. Stems of LLCR had larger diameter and proportionally larger air spaces than those of ULCR: a method of aerating submerged plant parts. The LLCR ecotype can also mobilize and use carbohydrate reserves under hypoxia, and it maintained relatively lower and steadier activity of alcohol dehydrogenase (ADH) as a measure of sustained anaerobic respiration. In contrast, ADH activity in ULCR increased faster upon a shift to hypoxia and then sharply decreased, suggesting depletion of available soluble sugar substrates. The LLCR ecotype also maintained lower lactate dehydrogenase activity under flooded conditions, which could reduce chances of cellular acidosis. Conclusions These adaptive traits in the LLCR ecotype were expressed constitutively, but some of them, such as tuber growth and aerenchyma development, are enhanced with stress severity. The LLCR ecotype attained numerous adaptive traits that could have evolved as a consequence of natural evolution or repeated management practices, and alternative strategies are necessary because

  8. Correlates between feeding ecology and mercury levels in historical and modern arctic foxes (Vulpes lagopus.

    Directory of Open Access Journals (Sweden)

    Natalia Bocharova

    Full Text Available Changes in concentration of pollutants and pathogen distribution can vary among ecotypes (e.g. marine versus terrestrial food resources. This may have important implications for the animals that reside within them. We examined 1 canid pathogen presence in an endangered arctic fox (Vulpes lagopus population and 2 relative total mercury (THg level as a function of ecotype ('coastal' or 'inland' for arctic foxes to test whether the presence of pathogens or heavy metal concentration correlate with population health. The Bering Sea populations on Bering and Mednyi Islands were compared to Icelandic arctic fox populations with respect to inland and coastal ecotypes. Serological and DNA based pathogen screening techniques were used to examine arctic foxes for pathogens. THg was measured by atomic absorption spectrometry from hair samples of historical and modern collected arctic foxes and samples from their prey species (hair and internal organs. Presence of pathogens did not correlate with population decline from Mednyi Island. However, THg concentration correlated strongly with ecotype and was reflected in the THg concentrations detected in available food sources in each ecotype. The highest concentration of THg was found in ecotypes where foxes depended on marine vertebrates for food. Exclusively inland ecotypes had low THg concentrations. The results suggest that absolute exposure to heavy metals may be less important than the feeding ecology and feeding opportunities of top predators such as arctic foxes which may in turn influence population health and stability. A higher risk to wildlife of heavy metal exposure correlates with feeding strategies that rely primarily on a marine based diet.

  9. Studies on the yield and quality characteristics of Myrtle (Myrtus communis L. grown in two different ecologies

    Directory of Open Access Journals (Sweden)

    Halil İbrahim UZUN

    2016-12-01

    Full Text Available Myrtle is a typical Mediterranean plant. Myrtles plants with white colored and large fruit sized are cultivated in southern coasts of Turkey and named as Hambeles. Black myrtles are naturally grown in the forests and they have smaller fruit size when compared to Hambeles. Main objective of this study was to investigate the yield and quality parameters of some newly selected 3 black myrtle ecotypes (Yakup, Yumaklar, Islangıc and one white myrtle cultivar (Hambeles in upland and lowland ecological conditions in Antalya. Yields, physical and chemical characters of fruits and essential oil composition of leaves were recorded for all plants. Two experimental orchards were established in coastal and highland conditions in Antalya. Highest fruit weight of black myrtles was measured as 0.76 g fruit-1 in Yakup ecotypes in highland and as 0.92 g fruit-1 in Yumaklar ecotypes in lowland. There were no differences among ecotypes in terms of fruit removal force. Fruit yield per tree increased up to 9.2 kg in black myrtle in lowland. Highest perfect seed numbers in myrtle plants were measured in Hambeles ecotype as 19.83 seeds fruit-1. Fruit juice yield ranged from 29.6 to 35.0%. Amount of malic acid in fruit was higher than that of other organic acids. α-pinene and 1,8-cineole were main essential oil components of myrtle leaves.

  10. Parallel evolution of local adaptation and reproductive isolation in the face of gene flow.

    Science.gov (United States)

    Butlin, Roger K; Saura, Maria; Charrier, Grégory; Jackson, Benjamin; André, Carl; Caballero, Armando; Coyne, Jerry A; Galindo, Juan; Grahame, John W; Hollander, Johan; Kemppainen, Petri; Martínez-Fernández, Mónica; Panova, Marina; Quesada, Humberto; Johannesson, Kerstin; Rolán-Alvarez, Emilio

    2014-04-01

    Parallel evolution of similar phenotypes provides strong evidence for the operation of natural selection. Where these phenotypes contribute to reproductive isolation, they further support a role for divergent, habitat-associated selection in speciation. However, the observation of pairs of divergent ecotypes currently occupying contrasting habitats in distinct geographical regions is not sufficient to infer parallel origins. Here we show striking parallel phenotypic divergence between populations of the rocky-shore gastropod, Littorina saxatilis, occupying contrasting habitats exposed to either wave action or crab predation. This divergence is associated with barriers to gene exchange but, nevertheless, genetic variation is more strongly structured by geography than by ecotype. Using approximate Bayesian analysis of sequence data and amplified fragment length polymorphism markers, we show that the ecotypes are likely to have arisen in the face of continuous gene flow and that the demographic separation of ecotypes has occurred in parallel at both regional and local scales. Parameter estimates suggest a long delay between colonization of a locality and ecotype formation, perhaps because the postglacial spread of crab populations was slower than the spread of snails. Adaptive differentiation may not be fully genetically independent despite being demographically parallel. These results provide new insight into a major model of ecologically driven speciation.

  11. Natural variation in Arabidopsis adaptation to growth at low nitrogen conditions.

    Science.gov (United States)

    North, Kathryn Anne; Ehlting, Barbara; Koprivova, Anna; Rennenberg, Heinz; Kopriva, Stanislav

    2009-10-01

    Improving nutrient use efficiency of crop plants, especially at low input, is essential to ensure sustainable food production in the future. In order to address the genetic basis of nutrient use efficiency in a model system, growth of Arabidopsis ecotypes at normal and low nitrogen (N) supply was compared. The ecotypes differed significantly in the extent of growth reduction in limiting conditions. The fresh weight of Shahdara and Ws grown at 1mM nitrate was reduced by 30% compared to control, whereas Col-0 and Ga-0 were almost unaffected. Total N content was reduced in all ecotypes by 10-30%. The capacity to store nitrate correlated with the tolerance to low N; in Shahdara and Ws, but not in Col-0 and Ga-0, nitrate content on low N was significantly reduced compared to control nutrition. The mRNA levels for genes of nitrate uptake and assimilation were only moderately affected by the treatment. The transcript levels of nitrate reductase NIA1 and nitrite reductase were higher in the ecotypes tolerant to low N (Col-0 and Ga-0) with normal N nutrition but on low N they were reduced to a much higher extent than the sensitive ecotypes (Shahdara and Ws). It seems that a higher capacity to keep nitrate reserves at low N, perhaps due to the ability to turn down nitrate reduction rate, is responsible for a better tolerance of Col-0 and Ga-0 to low N supply.

  12. Utilization of Genetic Diversity on Establishing Chinese Soybean (G.max0 Core Collection

    Institute of Scientific and Technical Information of China (English)

    QiuLijuan; XieHua; ChangRuzhen; LiWei; WangWenhui; ZhangBo; ZhangMinghui; FengZhongfu

    2002-01-01

    Genetic diversity plays a very important role in establishing core collection.In this study,A total of 405 Chinese soybean accessions was selected from the preliminary core collection,which had 5 different ecotypes from three cultivation regions,including northeastern spring sowing soybean(NSpSS),huanghuai summer sowing soybean(HSuSS),southern spring sowing soybean(SSpSS),southern summer sowing soybean(SSuSS),southern autumn sowing soybean(SAuSS).The genetic diversities and genetic relationship of five ecotypes were analyzed at DNA level by using SSR markers in order to provide information for establishemnt of Chinese soybean core collection.A set of 67 SSR primers were used to analyze these accessions,and detected 502 alleles with averaged 7.49 alleles per locus.SAuSS appeared to be the highest number of alleles,HSuSS had the biggest genetic diversity indexes and NSpSS were lowest for both numbers of alleles and genetic diversity indexes among 5 ecotypes.Since five ecotypes differentiated obviously,various sampling strategy for establishing core collection should be adaped for different ecotypes based on the number of alleles and genetic diversity indexes.

  13. Root Morphology and Zn2+ Uptake Kinetics of the Zn Hyperaccumulator of Sedum alfredii Hance

    Institute of Scientific and Technical Information of China (English)

    Ting-Qiang LI; Xiao-E YANG; Zhen-Li HE; Jin-Yan YANG

    2005-01-01

    Root morphology and Zn2+ uptake kinetics of the hyperaccumulating ecotype (HE) and nonhyperaccumulating ecotype (NHE) of Sedum alfredii Hance were investigated using hydroponic methods and the radiotracer flux technique. The results indicate that root length, root surface area, and root volume of NHE decreased significantly with increasing Zn2+ concentration in growth media, whereas the root growth of HE was not adversely affected, and was even promoted, by 500 μmol/L Zn2+. The concentrations of Zn2+ in both ecotypes of S. alfredii were positively correlated with root length, root surface area and root volumes, but no such correlation was found for root diameter. The uptake kinetics for 65Zn2+ in roots of both ecotypes of S. alfredii were characterized by a rapid linear phase during the first 6 h and a slower linear phase during the subsequent period of investigation. The concentration-dependent uptake kinetics of the two ecotypes of S. alfredii could be characterized by the Michaelis-Menten equation, with the Vmax for 65Zn2+ influx being threefold greater in HE compared with NHE, indicating that enhanced absorption into the root was one of the mechanisms involved in Zn hyperaccumulation. A significantly larger Vmax value suggested that there was a higher density of Zn transporters per unit membrane area in HE roots.

  14. Plants adapted to warmer climate do not outperform regional plants during a natural heat wave.

    Science.gov (United States)

    Bucharova, Anna; Durka, Walter; Hermann, Julia-Maria; Hölzel, Norbert; Michalski, Stefan; Kollmann, Johannes; Bossdorf, Oliver

    2016-06-01

    With ongoing climate change, many plant species may not be able to adapt rapidly enough, and some conservation experts are therefore considering to translocate warm-adapted ecotypes to mitigate effects of climate warming. Although this strategy, called assisted migration, is intuitively plausible, most of the support comes from models, whereas experimental evidence is so far scarce. Here we present data on multiple ecotypes of six grassland species, which we grew in four common gardens in Germany during a natural heat wave, with temperatures 1.4-2.0°C higher than the long-term means. In each garden we compared the performance of regional ecotypes with plants from a locality with long-term summer temperatures similar to what the plants experienced during the summer heat wave. We found no difference in performance between regional and warm-adapted plants in four of the six species. In two species, regional ecotypes even outperformed warm-adapted plants, despite elevated temperatures, which suggests that translocating warm-adapted ecotypes may not only lack the desired effect of increased performance but may even have negative consequences. Even if adaptation to climate plays a role, other factors involved in local adaptation, such as biotic interactions, may override it. Based on our results, we cannot advocate assisted migration as a universal tool to enhance the performance of local plant populations and communities during climate change.

  15. Does ozone exposure alter growth and carbon allocation of mycorrhizal plants

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, L.C.; Gamon, J.A. (California State Univ., Los Angeles, CA (United States)); Andersen, C.P. (Environmental Protection Agency, Corvallis, OR (United States))

    1994-06-01

    Ozone is known to adversely affect plant growth. However, it is less clear how ozone affects belowground processes. This study tests the hypothesis that ozone alters growth and carbon allocation of vesicular arbuscular mycorrhizal (VAM) plants. Two ecotypes of Elymus glaucus (blue wild rye) were exposed to mycorrhizal inoculation and episodic ozone exposures simulating atmospheric conditions in the Los Angeles Basin. Preliminary results show that effects of ozone on growth were subtle. In both ecotypes, growth of aboveground biomass was not affected by ozone while root growth was decreased. In most treatments, mycorrhizal inoculation decreased growth of leaves and stems, but had no significant effect on root growth. Three-way ANOVA tests indicated interactive effects between ecotype, mycorrhiza and ozone. Further experimental work is needed to reveal the biological processes governing these responses.

  16. PcTGD, a highly expressed gene in stem, is related to wa-ter stress in reed (Phragmites communis Trin.)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To compare differential gene expression among three ecotypes of reed (Phragmites communis Trin.), dune reed (DR), heavy-salt meadow reed (HSR) and light-salt meadow reed (LSR), mRNA transcripts were displayed by cDNA-AFLP (amplified fragment length polymorphisms). The result revealed that a relatively small number of genes are likely involved in adaptations of DR and HSR to stresses. A full-length cDNA encoding dTDP-D-glucose dehydratase gene (PcTGD) was subsequently cloned from DR. Northern blot analysis showed that it is highly expressed in stem as well as rhizoma of the three ecotypes. However, its expression in DR stem was much higher than that of the other two eco-types. After the removal of water stress, the expression of PcTGD was significantly reduced, suggesting that it possibly plays a role in adaptation of DR to water stress through an osmotic regulation mechanism.

  17. Partial migration in introduced wild chinook salmon (Oncorhynchus tshawytscha) of southern Chile

    Science.gov (United States)

    Araya, Miguel; Niklitschek, Edwin J.; Secor, Dave H.; Piccoli, Philip M.

    2014-08-01

    Partial migration, the incidence of opposing migration behaviors within the same population, has been a key factor in the invasive ecology of Pacific salmon within South America. Here, we examined such life-cycle variation in of an introduced chinook salmon population in the Aysén watershed, one of the largest fjord systems in NW Patagonia. The chinook salmon is the most successful invasive salmonid species in Patagonia and has recently colonized numerous Patagonian watersheds of the Pacific and Atlantic Oceans. Using analyses of fish scales and otolith strontium:calcium ratios, our results suggest the presence of two distinct ecotypes in the chinook population, an ocean type and a stream type, in a 3:2 ratio. The distribution of back-calculated length at the time of emigration from river to marine habitats showed a mode of 14 cm for the ocean ecotype and 30 cm for the stream ecotype. River residence time for the ocean ecotype ranged from 1 to 10 months, while that of the stream ecotype varied between 14 and 20 months. Returning adults reproduced in riverine habitats between August and March, but reproduction by the stream ecotype was limited to the period between October and February. Our results show that exotic chinook salmon populations established in NW Patagonia present a diversity of life-history strategies, which seems to be as large as the ones exhibited by the species in its native distribution range and in other invaded ecosystems. Chinook salmon have successfully invaded most major rivers in Patagonia, placing priority on science and conservation related to their ecological impact.

  18. Insulin-like signaling (IIS) responses to temperature, genetic background, and growth variation in garter snakes with divergent life histories.

    Science.gov (United States)

    Reding, Dawn M; Addis, Elizabeth A; Palacios, Maria G; Schwartz, Tonia S; Bronikowski, Anne M

    2016-07-01

    The insulin/insulin-like signaling pathway (IIS) has been shown to mediate life history trade-offs in mammalian model organisms, but the function of this pathway in wild and non-mammalian organisms is understudied. Populations of western terrestrial garter snakes (Thamnophis elegans) around Eagle Lake, California, have evolved variation in growth and maturation rates, mortality senescence rates, and annual reproductive output that partition into two ecotypes: "fast-living" and "slow-living". Thus, genes associated with the IIS network are good candidates for investigating the mechanisms underlying ecological divergence in this system. We reared neonates from each ecotype for 1.5years under two thermal treatments. We then used qPCR to compare mRNA expression levels in three tissue types (brain, liver, skeletal muscle) for four genes (igf1, igf2, igf1r, igf2r), and we used radioimmunoassay to measure plasma IGF-1 and IGF-2 protein levels. Our results show that, in contrast to most mammalian model systems, igf2 mRNA and protein levels exceed those of igf1 and suggest an important role for igf2 in postnatal growth in reptiles. Thermal rearing treatment and recent growth had greater impacts on IGF levels than genetic background (i.e., ecotype), and the two ecotypes responded similarly. This suggests that observed ecotypic differences in field measures of IGFs may more strongly reflect plastic responses in different environments than evolutionary divergence. Future analyses of additional components of the IIS pathway and sequence divergence between the ecotypes will further illuminate how environmental and genetic factors influence the endocrine system and its role in mediating life history trade-offs.

  19. Mitochondrial divergence between slow- and fast-aging garter snakes.

    Science.gov (United States)

    Schwartz, Tonia S; Arendsee, Zebulun W; Bronikowski, Anne M

    2015-11-01

    Mitochondrial function has long been hypothesized to be intimately involved in aging processes--either directly through declining efficiency of mitochondrial respiration and ATP production with advancing age, or indirectly, e.g., through increased mitochondrial production of damaging free radicals with age. Yet we lack a comprehensive understanding of the evolution of mitochondrial genotypes and phenotypes across diverse animal models, particularly in species that have extremely labile physiology. Here, we measure mitochondrial genome-types and transcription in ecotypes of garter snakes (Thamnophis elegans) that are adapted to disparate habitats and have diverged in aging rates and lifespans despite residing in close proximity. Using two RNA-seq datasets, we (1) reconstruct the garter snake mitochondrial genome sequence and bioinformatically identify regulatory elements, (2) test for divergence of mitochondrial gene expression between the ecotypes and in response to heat stress, and (3) test for sequence divergence in mitochondrial protein-coding regions in these slow-aging (SA) and fast-aging (FA) naturally occurring ecotypes. At the nucleotide sequence level, we confirmed two (duplicated) mitochondrial control regions one of which contains a glucocorticoid response element (GRE). Gene expression of protein-coding genes was higher in FA snakes relative to SA snakes for most genes, but was neither affected by heat stress nor an interaction between heat stress and ecotype. SA and FA ecotypes had unique mitochondrial haplotypes with amino acid substitutions in both CYTB and ND5. The CYTB amino acid change (Isoleucine → Threonine) was highly segregated between ecotypes. This divergence of mitochondrial haplotypes between SA and FA snakes contrasts with nuclear gene-flow estimates, but correlates with previously reported divergence in mitochondrial function (mitochondrial oxygen consumption, ATP production, and reactive oxygen species consequences).

  20. Rice blast fungus (Magnaporthe oryzae) infects Arabidopsis via a mechanism distinct from that required for the infection of rice.

    Science.gov (United States)

    Park, Ju-Young; Jin, Jianming; Lee, Yin-Won; Kang, Seogchan; Lee, Yong-Hwan

    2009-01-01

    Magnaporthe oryzae is a hemibiotrophic fungal pathogen that causes rice (Oryza sativa) blast. Although M. oryzae as a whole infects a wide variety of monocotyledonous hosts, no dicotyledonous plant has been reported as a host. We found that two rice pathogenic strains of M. oryzae, KJ201 and 70-15, interacted differentially with 16 ecotypes of Arabidopsis (Arabidopsis thaliana). Strain KJ201 infected all ecotypes with varying degrees of virulence, whereas strain 70-15 caused no symptoms in certain ecotypes. In highly susceptible ecotypes, small chlorotic lesions appeared on infected leaves within 3 d after inoculation and subsequently expanded across the affected leaves. The fungus produced spores in susceptible ecotypes but not in resistant ecotypes. Fungal cultures recovered from necrotic lesions caused the same symptoms in healthy plants, satisfying Koch's postulates. Histochemical analyses showed that infection by the fungus caused an accumulation of reactive oxygen species and eventual cell death. Similar to the infection process in rice, the fungus differentiated to form appressorium and directly penetrated the leaf surface in Arabidopsis. However, the pathogenic mechanism in Arabidopsis appears distinct from that in rice; three fungal genes essential for pathogenicity in rice played only limited roles in causing disease symptoms in Arabidopsis, and the fungus seems to colonize Arabidopsis as a necrotroph through the secretion of phytotoxic compounds, including 9,12-octadecadienoic acid. Expression of PR-1 and PDF1.2 was induced in response to infection by the fungus, suggesting the activation of salicylic acid- and jasmonic acid/ethylene-dependent signaling pathways. However, the roles of these signaling pathways in defense against M. oryzae remain unclear. In combination with the wealth of genetic and genomic resources available for M. oryzae, this newly established pathosystem allows comparison of the molecular and cellular mechanisms underlying

  1. Genetic and histological studies on the delayed systemic movement of Tobacco Mosaic Virus in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Matus José

    2008-09-01

    Full Text Available Abstract Background Viral infections and their spread throughout a plant require numerous interactions between the host and the virus. While new functions of viral proteins involved in these processes have been revealed, current knowledge of host factors involved in the spread of a viral infection is still insufficient. In Arabidopsis thaliana, different ecotypes present varying susceptibilities to Tobacco mosaic virus strain U1 (TMV-U1. The rate of TMV-U1 systemic movement is delayed in ecotype Col-0 when compared with other 13 ecotypes. We followed viral movement through vascular tissue in Col-0 plants by electronic microscopy studies. In addition, the delay in systemic movement of TMV-U1 was genetically studied. Results TMV-U1 reaches apical leaves only after 18 days post rosette inoculation (dpi in Col-0, whereas it is detected at 9 dpi in the Uk-4 ecotype. Genetic crosses between Col-0 and Uk-4 ecotypes, followed by analysis of viral movement in F1 and F2 populations, revealed that this delayed movement correlates with a recessive, monogenic and nuclear locus. The use of selected polymorphic markers showed that this locus, denoted DSTM1 (Delayed Systemic Tobamovirus Movement 1, is positioned on the large arm of chromosome II. Electron microscopy studies following the virion's route in stems of Col-0 infected plants showed the presence of curved structures, instead of the typical rigid rods of TMV-U1. This was not observed in the case of TMV-U1 infection in Uk-4, where the observed virions have the typical rigid rod morphology. Conclusion The presence of defectively assembled virions observed by electron microscopy in vascular tissue of Col-0 infected plants correlates with a recessive delayed systemic movement trait of TMV-U1 in this ecotype.

  2. MORPHOMETRIC DIFFERENCES BETWEEN HONEY BEES (Apis mellifera carpatica POPULATIONS FROM TRANSYLVANIAN AREA

    Directory of Open Access Journals (Sweden)

    L. AL. MĂRGHITAS

    2013-12-01

    Full Text Available The result of the long evolutionary process formed, by natural selection, variable races and ecotypes which are biological and ecological differentiated. The Romanian, Apis mellifera carpatica is the most adapted and the most efficient species at the local conditions. Morphometric measurements were the major criteria for classification described by Ruttner (1988 and are the basis of our study. In this way 8 morphometric characters of honeybees from Transylvanian region were measured. The data obtained show that the honeybees’ ecotype genes are mixed due to the migratory beekeeping.

  3. The influence of ecology on sociality in the killer whale (Orcinus orca)

    DEFF Research Database (Denmark)

    Beck, Suzanne; Kuningas, Sanna; Esteban, Ruth

    2012-01-01

    The persistence and size of social groups can be plastic and governed by ecological selection or be under greater genetic control and constrained by phylogenetic inertia. Comparing sociality of phylogenetically divergent populations under the same ecolog- ical conditions or between groups within......-eating ecotype than the more phylogenetically distant Pacific mammal-eating ecotype. Our study suggests that sociality in killer whales is to some extent plastic and can be adapted to the local ecological conditions. Key words: ecology, killer whale, orca, orcinus, sociality....

  4. Reference: 490 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available tration. The heterologous expression in yeast was utilized to verify that the AtP...TR3 protein transports di-and tripeptides. The T-DNA insert in the Atptr3-1 mutant in the Arabidopsis ecotype C24 re...tr3-2 mutant of the Col-0 ecotype. The AtPTR3 expression was shown to be regulated by several signalling com...d in the SA and JA signalling mutants. The Atptr3 mutant plants had increased susceptibility to virulent pat...hogenic bacteria Erwinia carotovora subsp. carotovora and Pseudomonas syringae pv. tomato, and produced more re

  5. Arabidopsis PAI gene arrangements, cytosine methylation and expression.

    OpenAIRE

    Melquist, S.; Luff, B; Bender, J.

    1999-01-01

    Previous analysis of the PAI tryptophan biosynthetic gene family in Arabidopsis thaliana revealed that the Wassilewskija (WS) ecotype has four PAI genes at three unlinked sites: a tail-to-tail inverted repeat at one locus (PAI1-PAI4) plus singlet genes at two other loci (PAI2 and PAI3). The four WS PAI genes are densely cytosine methylated over their regions of DNA identity. In contrast, the Columbia (Col) ecotype has three singlet PAI genes at the analogous loci (PAI1, PAI2, and PAI3) and no...

  6. QTL Information Table: 529 [Q-TARO

    Lifescience Database Archive (English)

    Full Text Available RG213 C235 pha Yan, C.J., Liang, G.H., Zhu, L.H., and Gu, M.H. (2000). RFLP analysis on wide compatibility genes in rice variety dular of ecotype aus. Yi Chuan Xue Bao 27, 409-417. ...

  7. Induced systemic resistance in Arabidopsis against Pseudomonas syringae pv. tomato by disease suppressive soils

    Science.gov (United States)

    Two-week-old Arabidopsis thaliana ecotype Col-0 seedlings were transferred into an autoclaved sand-soil mixture amended with 10% or 20% (weight/weight) soil that is suppressive to either take-all or Rhizoctonia root rot of wheat from fields in Washington State USA. These soils contain population siz...

  8. Zn Accumulation and Subcellular Distribution in the Zn Hyperaccumulator Sedum alfredii Hance

    Institute of Scientific and Technical Information of China (English)

    LI Ting-Qiang; YANG Xiao-E; YANG Jin-Yan; HE Zhen-Li

    2006-01-01

    Zn accumulation and subcellular distribution in leaves of the hyperaccumulating ecotype (HE) and non-hyperaccumulating ecotype (NHE) of Sedum alfredii Hance were studied using radiotracer and gradient centrifugation techniques. Leaf Zn accumulation in the HE of S. alfredii was 18.5-26.7 times greater than that in the NHE when the plants were grown at 1-500μmol Zn L-1. Leaf section uptake of 65Zn was highly dependent on external Zn levels. Greater 65Zn uptake in HE was noted only at external Zn levels ≥ 100μmol L-1. Zinc subcellular distribution in the leaves of the two ecotypes of S. alfredii was: cell wall > soluble fraction > cell organelle. However, more Zn was distributed to the leaf cell wall and soluble fractions for HE than for NHE. In the leaf of HE, 91%-94% of the Zn was found in the cell walls and the soluble fraction and only 6%-9% Zn was distributed in the cell organelle fraction. For NHE, about 20%-26% Zn was recovered in the cell organelle fraction. In stems, Zn distribution to the cell wall fraction was approximately two fold greater in the HE than that in the NHE. For the hyperaccumulating ecotype of S. alfredii, the cell wall and the vacuole played a very important role in Zn tolerance and hyperaccumulation.

  9. Plant performance: a physiological and genetic analysis using Arabidopsis thaliana natural variation

    NARCIS (Netherlands)

    El-Lithy, M.E.M.

    2005-01-01

    Plant performance implies complex traits, controlled by a large set of genes and affected by the environment. In this thesis we have tried to take the first steps in unravelling the genes controlling plant performance using naturally occurring accessions (ecotypes) of the model plant Arabidopsis

  10. Reference: 538 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available d A et al. 2007 Apr. Plant Physiol. 143(4):1576-89. Membrane proteins within the sieve element-companion cel...psis (Arabidopsis thaliana) ecotype Columbia that is associated specifically with the plasma membrane of sieve elements, but not comp...anion cells, and accumulates at the earliest stages of s

  11. In Situ Hydrogen Dynamics in a Hot Spring Microbial Mat during a Diel Cycle

    DEFF Research Database (Denmark)

    Revsbech, Niels Peter; Trampe, Erik Christian Løvbjerg; Lichtenberg, Mads

    2016-01-01

    in a hot spring microbial mat, where various ecotypes of unicellular cyanobacteria (Synechococcus sp.) are the only oxygenic phototrophs. In the evening, H2 accumulated rapidly after the onset of darkness, reaching peak values of up to 30 mol H2 liter1 at about 1-mm depth below the mat surface, slowly...

  12. Distribution, Abundance and Population Structuring of Beaked Whales in the Great Bahama Canyon, Northern Bahamas

    Science.gov (United States)

    2007-01-01

    Atlantic bottlenose dolphin - coastal ecotype ( Tursiops truncatus ) 2 3.0 3 – 3 6 Unknown Delphinid species 1 1.0 1 – 1 2...in S.H. Ridgeway and R. Harrison, eds. Handbook of marine mammals. Vol. 4. River dolphins and the larger toothed whales. Academic Press, London, UK

  13. The genetic basis of adaptive population differentiation: A quantitative trait locus analysis of fitness traits in two wild barley populations from contrasting habitats

    NARCIS (Netherlands)

    Verhoeven, K.J.F.; Vanhala, T.K.; Biere, A.; Nevo, E.; Damme, van J.M.M.

    2004-01-01

    We used a quantitative trait locus (QTL) approach to study the genetic basis of population differentiation in wild barley, Hordeum spontaneum. Several ecotypes are recognized in this model species, and population genetic studies and reciprocal transplant experiments have indicated the role of local

  14. LysM domain receptor kinases regulating rhizobial Nod factor-induced infection

    NARCIS (Netherlands)

    Limpens, E.H.M.; Franken, C.L.; Smit, P.E.J.; Willemse, J.J.; Bisseling, T.; Geurts, R.

    2003-01-01

    The rhizobial infection of legumes has the most stringent demand toward Nod factor structure of all host responses, and therefore a specific Nod factor entry receptor has been proposed. The SYM2 gene identfied in certain ecotypes of pea (Pisum sativum) is a good candidate for such an entry receptor.

  15. Genetic analysis of induced systemic resistance in Arabidopsis thaliana: association between induced and basal resistance

    NARCIS (Netherlands)

    Ton, J.; Pieterse, C.M.J.; Loon, L.C. van

    1998-01-01

    Selected nonpathogenic rhizobacteria are able to elicit induced systemic resistance (ISR) in plants. Different ecotypes of Arabidopsis thaliana were screened for expression of ISR against infection by Pseudomonas syringae pv. tomato, after treatment of the roots with the nonpathogenic P. fluorescens

  16. Gene–culture coevolution in whales and dolphins

    Science.gov (United States)

    Whitehead, Hal

    2017-01-01

    Whales and dolphins (Cetacea) have excellent social learning skills as well as a long and strong mother–calf bond. These features produce stable cultures, and, in some species, sympatric groups with different cultures. There is evidence and speculation that this cultural transmission of behavior has affected gene distributions. Culture seems to have driven killer whales into distinct ecotypes, which may be incipient species or subspecies. There are ecotype-specific signals of selection in functional genes that correspond to cultural foraging behavior and habitat use by the different ecotypes. The five species of whale with matrilineal social systems have remarkably low diversity of mtDNA. Cultural hitchhiking, the transmission of functionally neutral genes in parallel with selective cultural traits, is a plausible hypothesis for this low diversity, especially in sperm whales. In killer whales the ecotype divisions, together with founding bottlenecks, selection, and cultural hitchhiking, likely explain the low mtDNA diversity. Several cetacean species show habitat-specific distributions of mtDNA haplotypes, probably the result of mother–offspring cultural transmission of migration routes or destinations. In bottlenose dolphins, remarkable small-scale differences in haplotype distribution result from maternal cultural transmission of foraging methods, and large-scale redistributions of sperm whale cultural clans in the Pacific have likely changed mitochondrial genetic geography. With the acceleration of genomics new results should come fast, but understanding gene–culture coevolution will be hampered by the measured pace of research on the socio-cultural side of cetacean biology. PMID:28739936

  17. Feasilbility of phytoextraction to remediate cadmium and zinc contaminated soils

    NARCIS (Netherlands)

    Koopmans, G.F.; Romkens, P.F.A.M.; Fokkema, M.J.; Song, J.; Luo, Y.M.; Japenga, J.; Zhao, F.J.

    2008-01-01

    A Cd and Zn contaminated soil was mixed and equilibrated with an uncontaminated, but otherwise similar soil to establish a gradient in soil contamination levels. Growth of Thlaspi caerulescens (Ganges ecotype) significantly decreased the metal concentrations in soil solution. Plant uptake of Cd and

  18. Five species, many genotypes, broad phenotypic diversity: When agronomy meets functional ecology.

    Science.gov (United States)

    Prieto, Ivan; Litrico, Isabelle; Violle, Cyrille; Barre, Philippe

    2017-01-01

    Current ecological theory can provide insight into the causes and impacts of plant domestication. However, just how domestication has impacted intraspecific genetic variability (ITV) is unknown. We used 50 ecotypes and 35 cultivars from five grassland species to explore how selection drives functional trait coordination and genetic differentiation. We quantified the extent of genetic diversity among different sets of functional traits and determined how much genetic diversity has been generated within populations of natural ecotypes and selected cultivars. In general, the cultivars were larger (e.g., greater height, faster growth rates) and had larger and thinner leaves (greater SLA). We found large (average 63%) and trait-dependent (ranging from 14% for LNC to 95.8% for growth rate) genetic variability. The relative extent of genetic variability was greater for whole-plant than for organ-level traits. This pattern was consistent within ecotypes and within cultivars. However, ecotypes presented greater ITV variability. The results indicated that genetic diversity is large in domesticated species with contrasting levels of heritability among functional traits and that selection for high yield has led to indirect selection of some associated leaf traits. These findings open the way to define which target traits should be the focus in selection programs, especially in the context of community-level selection. © 2017 Botanical Society of America.

  19. Phenol-oxidizing peroxidases contribute to the protection of plants from ultraviolet radiation stress

    NARCIS (Netherlands)

    Jansen, M.A.K.; Noort, van den R.E.; Tan, M.Y.A.; Prinsen, E.; Lagrimini, L.M.; Thorneley, R.N.F.

    2001-01-01

    We have studied the mechanism of UV protection in two duckweed species (Lemnaceae) by exploiting the UV sensitivity of photosystem II as an in situ sensor for radiation stress. A UV-tolerant Spirodela punctata G.F.W. Meyer ecotype had significantly higher indole-3-acetic acid (IAA) levels than a UV-

  20. Switchgrass cultivars alter microbial contribution to deep soil C in Nebraska

    Science.gov (United States)

    Switchgrass (Panicum virgatum L.) is a C4, perennial grass that is being developed as a bioenergy crop for the United States. While aboveground biomass production is well documented for switchgrass ecotypes (lowland, upland) and cultivars, there has been little focus on the impact of plant belowgro...

  1. Zinc adsorption and desorption characteristics in root cell wall involving zinc hyperaccumulation in Sedum alfredii Hance.

    Science.gov (United States)

    Li, Ting-qiang; Yang, Xiao-e; Meng, Fan-hua; Lu, Ling-li

    2007-02-01

    Radiotracer techniques were employed to characterize (65)Zn adsorption and desorption in root-cell-wall of hyperaccumulating ecotype (HE) and non-hyperaccumulating ecotype (NHE) species of Sedum alfredii Hance. The results indicated that at the end of a 30 min short time radioisotope loading period, comparable amounts of (65)Zn were accumulated in the roots of the two ecotypes Sedum alfredii, whereas 2.1-fold more (65)Zn remains in NHE root after 45-min desorption. At the end of 60 min uptake period, no difference of (65)Zn accumulation was observed in undesorbed root-cell-wall of Sedum alfredii. However, 3.0-fold more (65)Zn accumulated in desorbed root-cell-wall of NHE. Zn(2+) binding in root-cell-wall preparations of NHE was greater than that in HE under high Zn(2+) concentration. All these results suggested that root-cell-wall of the two ecotypes Sedum alfredii had the same ability to adsorb Zn(2+), whereas the desorption characteristics were different, and with most of (65)Zn binding on root of HE being available for loading into the xylem, as a result, more (65)Zn was translocated to the shoot.

  2. 12th North American Caribou Workshop, 2-5 November 2008, Happy Valley – Goose Bay, Newfoundland and Labrador, Canada.

    Directory of Open Access Journals (Sweden)

    Rolf Egil Haugerud (editor in chief

    2011-09-01

    Full Text Available The 12th NACW was arranged at Happy Valley - Goose Bay 4-6 November 2008 with the theme "Integrating Understanding across Ecotypes". Approximately 140 people attended from Canada, United States, Norway, and Greenland. The 12th NACW included more than 70 oral and poster presentations.

  3. Death and cannibalism in a seasonal environment facilitate bacterial coexistence

    NARCIS (Netherlands)

    Rozen, D.E.; Philippe, N.; Visser, de J.A.G.M.; Lenski, R.E.; Schneider, D.

    2009-01-01

    Bacterial populations can evolve and adapt to become diverse niche specialists, even in seemingly homogeneous environments. One source of this diversity arises from newly 'constructed' niches that result from the activities of the bacteria themselves. Ecotypes specialized to exploit these distinct n

  4. Manufacture and Low Power Measurement of Ridgetron Cavity

    Institute of Scientific and Technical Information of China (English)

    LI; Jin-hai; LI; Chun-guang

    2015-01-01

    The ridgetron is the new type accelerator,and is mainly to use in the electron irradiation field.The electron irradiation technology is a high efficiency,ecotypic,secure,new technology.It can be used in food process for sterilize,preservation,inhibition of burgeon,and so on.The ridgetron is operated in CW mode,

  5. Phenotypic characterisation and molecular polymorphism of ...

    African Journals Online (AJOL)

    PRECIOUS

    2010-01-18

    Jan 18, 2010 ... was carried out in Benin on 326 chickens of the Forest ecological area and .... locus (black extension) includes several alleles which are asso- ... This model included the fixed effects of the ecotype and ..... Apart from a mixed type colour, all the .... Youssao AKI, Adehan R, Kpodekon M, Bonou G, Dougnon J,.

  6. An evolutionary and functional genomics study of Noccaea caerulescens, a heavy metal hyperaccumulating plant species

    NARCIS (Netherlands)

    Wang, Y.

    2016-01-01

    Noccaea caerulescens is the only known Zn/Cd/Ni hyperaccumulator. The Ganges accession (2n = 14) has an, yet unpublished, genome size of ~319 Mb, with 29,712 predicted genes representing 15,874 gene families. This species is distributed mainly in Europe. Three ecotypes can be distinguished: two

  7. The detoxification of lead in Sedum alfredii H. is not related to phytochelatins but the glutathione.

    Science.gov (United States)

    Gupta, D K; Huang, H G; Yang, X E; Razafindrabe, B H N; Inouhe, M

    2010-05-15

    Two ecotypes of S. alfredii [Pb accumulating (AE) and Pb non-accumulating (NAE)] differing in their ability in accumulating Pb were exposed to different Pb levels to evaluate the effects on plant length, photosynthetic pigments, antioxidant enzymes (SOD and APX), cysteine, non-protein thiols (NP-SH), phytochelatins (PCs) and glutathione (GSH) vis-à-vis Pb accumulation. Both ecotypes showed significant Pb accumulation in roots, however only the AE showed significant Pb accumulation in shoots. We found that both AE and NAE of S. alfredii-induced biosynthesis of GSH rather than phytochelatins in their tissue upon addition of even high Pb levels (200 microM). Root and shoot length were mostly affected in both ecotypes after addition of higher Pb concentrations and on longer durations, however photosynthetic pigments did not alter upon addition of any Pb treatment. Both superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities of AE were higher than NAE. The levels of cysteine and NP-SH were also higher in AE than in NAE. Hence, the characteristic Pb accumulation of ecotypes differed presumably in relation to their capacity for detoxification of Pb. These results suggest that enzymatic and non-enzymatic antioxidants play a key role in the detoxification of Pb-induced toxic effects in Sedum alfredii. This plant can be used as an indicator species for Pb contamination.

  8. The USDA Feed the Future Initiative for genetic improvement of African goats: an update on genomic resources and genetic characterization of indigenous breeds

    Science.gov (United States)

    Food production systems in Africa depend heavily on the use of locally adapted animals such as goats which are critical to small-scale farmers as they are easier to acquire, maintain, and act as scavengers in sparse pasture and marginal crop regions. Indigenous goat ecotypes have undergone generatio...

  9. The evolutionary forces maintaining a wild polymorphism of Littorina saxatilis: model selection by computer simulations.

    Science.gov (United States)

    Pérez-Figueroa, A; Cruz, F; Carvajal-Rodríguez, A; Rolán-Alvarez, E; Caballero, A

    2005-01-01

    Two rocky shore ecotypes of Littorina saxatilis from north-west Spain live at different shore levels and habitats and have developed an incomplete reproductive isolation through size assortative mating. The system is regarded as an example of sympatric ecological speciation. Several experiments have indicated that different evolutionary forces (migration, assortative mating and habitat-dependent selection) play a role in maintaining the polymorphism. However, an assessment of the combined contributions of these forces supporting the observed pattern in the wild is absent. A model selection procedure using computer simulations was used to investigate the contribution of the different evolutionary forces towards the maintenance of the polymorphism. The agreement between alternative models and experimental estimates for a number of parameters was quantified by a least square method. The results of the analysis show that the fittest evolutionary model for the observed polymorphism is characterized by a high gene flow, intermediate-high reproductive isolation between ecotypes, and a moderate to strong selection against the nonresident ecotypes on each shore level. In addition, a substantial number of additive loci contributing to the selected trait and a narrow hybrid definition with respect to the phenotype are scenarios that better explain the polymorphism, whereas the ecotype fitnesses at the mid-shore, the level of phenotypic plasticity, and environmental effects are not key parameters.

  10. Evolution in Littorina: ecology matters

    Science.gov (United States)

    Johannesson, Kerstin

    2003-03-01

    Organisms of marine rocky shores are exposed to physical stress from abiotic factors, such as temperature, salinity and wave action. These factors vary over compressed temporal and spatial scales, producing an exceedingly heterogeneous habitat with steep gradients of selection, and it seems likely that this has a strong influence on the evolution of populations of rocky shore organisms. With the periwinkles (genus Littorina) as a model group, I review strategies for coping with small-scale heterogeneous environments and what implications these strategies have on the evolution of these species. Some species of Littorina have long-lived pelagic larvae and sites of various habitats are thus recruited from a common gene pool. This largely prevents local adaptation but minor adjustments are possible through a plastic phenotype. Other species of the genus are directly developing with no larval dispersal and among these there is evidence of strong local adaptation forming distinct ecotypes in contrasting habitats by parallel evolution. In at least one of the directly developing species ( L. saxatilis) divergent selection among ecotypes has resulted in partial reproductive barriers that further impede gene flow among ecotypes. Furthermore, convergent evolution among species has produced superficially similar morphs in different habitats. Ecotype formation, ecological reproductive barriers and convergence among species all indicate that ecological processes are critical for evolution of Littorina species.

  11. Development of a New Marker System for Identification of Spirodela polyrhiza and Landoltia punctata

    Directory of Open Access Journals (Sweden)

    Bo Feng

    2017-01-01

    Full Text Available Lemnaceae (commonly called duckweed is an aquatic plant ideal for quantitative analysis in plant sciences. Several species of this family represent the smallest and fastest growing flowering plants. Different ecotypes of the same species vary in their biochemical and physiological properties. Thus, selecting of desirable ecotypes of a species is very important. Here, we developed a simple and rapid molecular identification system for Spirodela polyrhiza and Landoltia punctata based on the sequence polymorphism. First, several pairs of primers were designed and three markers were selected as good for identification. After PCR amplification, DNA fragments (the combination of three PCR products in different duckweeds were detected using capillary electrophoresis. The high-resolution capillary electrophoresis displayed high identity to the sequencing results. The combination of the PCR products containing several DNA fragments highly improved the identification frequency. These results indicate that this method is not only good for interspecies identification but also ideal for intraspecies distinguishing. Meanwhile, 11 haplotypes were found in both the S. polyrhiza and L. punctata ecotypes. The results suggest that this marker system is useful for large-scale identification of duckweed and for the screening of desirable ecotypes to improve the diverse usage in duckweed utilization.

  12. Ribosomal DNA internal transcribed spacer 1 and internal ...

    African Journals Online (AJOL)

    USER

    2010-07-26

    Jul 26, 2010 ... regions for each ecotype and conducted the sequence length, G+C content (%) ..... results (BEMR, GCSL and GRDG) were selected and compared with the ... 2C DNA content to evaluate the phylogenetic relation- ships between 25 ..... This work was supported by Nutraceutical Bio Brain. Korea 21 Project ...

  13. PCR bias in ecological analysis: A case study for quantitative Taq nuclease assays in analyses of microbial communities

    NARCIS (Netherlands)

    Becker, S.; Boger, P.; Oehlmann, R.; Ernst, A.

    2000-01-01

    Succession of ecotypes, physiologically diverse strains with negligible rRNA sequence divergence, may explain the dominance of small, red-pigmented (phycoerythrin-rich) cyanobacteria in the autotrophic picoplankton of deep lakes (C, Postius and A. Ernst, Arch. Microbiol, 172:69-75, 1999), In order t

  14. Gene-culture coevolution in whales and dolphins.

    Science.gov (United States)

    Whitehead, Hal

    2017-07-24

    Whales and dolphins (Cetacea) have excellent social learning skills as well as a long and strong mother-calf bond. These features produce stable cultures, and, in some species, sympatric groups with different cultures. There is evidence and speculation that this cultural transmission of behavior has affected gene distributions. Culture seems to have driven killer whales into distinct ecotypes, which may be incipient species or subspecies. There are ecotype-specific signals of selection in functional genes that correspond to cultural foraging behavior and habitat use by the different ecotypes. The five species of whale with matrilineal social systems have remarkably low diversity of mtDNA. Cultural hitchhiking, the transmission of functionally neutral genes in parallel with selective cultural traits, is a plausible hypothesis for this low diversity, especially in sperm whales. In killer whales the ecotype divisions, together with founding bottlenecks, selection, and cultural hitchhiking, likely explain the low mtDNA diversity. Several cetacean species show habitat-specific distributions of mtDNA haplotypes, probably the result of mother-offspring cultural transmission of migration routes or destinations. In bottlenose dolphins, remarkable small-scale differences in haplotype distribution result from maternal cultural transmission of foraging methods, and large-scale redistributions of sperm whale cultural clans in the Pacific have likely changed mitochondrial genetic geography. With the acceleration of genomics new results should come fast, but understanding gene-culture coevolution will be hampered by the measured pace of research on the socio-cultural side of cetacean biology.

  15. ACID/HEAVY METAL TOLERANT PLANTS

    Science.gov (United States)

    This report summarizes the results of Mine Waste Technology Program (MWTP) Activity III, Project 30. The objective of Project 30 was to select populations (i.e., ecotypes) from native, indigenous plant species that demonstrate superior growth characteristics and sustainability on...

  16. 77 FR 71041 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Southern...

    Science.gov (United States)

    2012-11-28

    ... winter food, arboreal lichens, occurs. The term ``mountain caribou'' is a common designation used throughout the scientific literature to describe the mountain/arboreal- lichen feeding ecotype of woodland... recreation, fires, and road building, management and control of predators and or prey species, previous...

  17. Experiment list: SRX1428007 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available .7,0 ChIP Tfap2c in Mus musculus: TSC breed=not applicable || cultivar=not applicable || ecotype=not applicable... || isolate=not applicable || strain=not applicable || age=not applicable || dev_stage=not applicable ||

  18. Experiment list: SRX1428006 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available 6,0 ChIP input control in Mus musculus: TSC breed=not applicable || cultivar=not applicable || ecotype=not applicable... || isolate=not applicable || strain=not applicable || age=not applicable || dev_stage=not applicable

  19. Experiment list: SRX1428005 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available 1.3,0 ChIP Tfap2c in Mus musculus: 24 diff TSC breed=not applicable || cultivar=not applicable || ecotype=not applicable... || isolate=not applicable || strain=not applicable || age=not applicable || dev_stage=not applicable

  20. Experiment list: SRX1428009 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available 39.7,7042 ChIP Elf5 in Mus musculus: f TSC breed=not applicable || cultivar=not applicable || ecotype=not applicable... || isolate=not applicable || strain=not applicable || age=not applicable || dev_stage=not applicable

  1. Host plant use drives genetic differentiation in syntopic populations of Maculinea alcon

    DEFF Research Database (Denmark)

    Tartally, András; Kelager, Andreas; Fürst, Matthias Alois

    2016-01-01

    host ant nest relatedness, indicating very limited dispersal of most ovipositing females, but not association with particular host ant species. Our results are consistent with the results of larger scale phylogeographic studies that suggest that the two forms represent local ecotypes specialising...

  2. A rearrangement of the Z chromosome topology influences the sex-linked gene display in the European corn borer, Ostrinia nubilalis

    Science.gov (United States)

    The sex determination system of Lepidoptera is comprised of heterogametic females (ZW) and homogametic males (ZZ), where voltinism (Volt) and the male pheromone response traits (Resp) are controlled by genes housed on the Z-chromosome. Volt and Resp determine traits that lead to ecotype differentia...

  3. Silicified structures affect leaf optical properties in grasses and sedge.

    Science.gov (United States)

    Klančnik, Katja; Vogel-Mikuš, Katarina; Gaberščik, Alenka

    2014-01-05

    Silicon (Si) is an important structural element that can accumulate at high concentrations in grasses and sedges, and therefore Si structures might affect the optical properties of the leaves. To better understand the role of Si in light/leaf interactions in species rich in Si, we examined the total Si and silica phytoliths, the biochemical and morphological leaf properties, and the reflectance and transmittance spectra in grasses (Phragmites australis, Phalaris arundinacea, Molinia caerulea, Deschampsia cespitosa) and sedge (Carex elata). We show that these grasses contain >1% phytoliths per dry mass, while the sedge contains only 0.4%. The data reveal the variable leaf structures of these species and significant differences in the amount of Si and phytoliths between developing and mature leaves within each species and between grasses and sedge, with little difference seen among the grass species. Redundancy analysis shows the significant roles of the different near-surface silicified leaf structures (e.g., prickle hairs, cuticle, epidermis), phytoliths and Si contents, which explain the majority of the reflectance and transmittance spectra variability. The amount of explained variance differs between mature and developing leaves. The transmittance spectra are also significantly affected by chlorophyll a content and calcium levels in the leaf tissue.

  4. LOS MUSGOS (BRYOPHYTA DE LA REGIÓN DE SANTA MARÍA-BOYACÁ (COLOMBIA

    Directory of Open Access Journals (Sweden)

    AVENDAÑO-TORRES KARINA

    2007-06-01

    Full Text Available En la región de Santa María (Boyacá se registraron 68 especies de musgos,pertenecientes a 45 géneros y 21 familias; 22 taxones son nuevos registros para eldepartamento. Las familias más ricas en géneros y especies fueron: Hypnaceae (8géneros - 8 especies, Meteoriaceae (6-7, Pilotrichaceae (4-7 y Fissidentaceae (1-6. Los géneros más ricos en especies fueron: Fissidens (6 y Syrrhopodon (3. Lacomposición por región de vida fue para la tropical de 63 especies en 45 génerosy 21 familias y para la subandina 22 especies de 19 géneros y 15 familias. Las dosregiones comparten 17 especies, en 17 géneros y 14 familias. Los hábitats (sustratosmás diversos fueron: epífi tos (16 especies, epilíticos (8 y epilítico-terrestres (8,doce especies se presentaron en todos los sustratos. Las formas de vida con mayorrepresentación fueron: cespitosas cortas (24 y felpas lisas (17.

  5. MUSGOS (BRYOPHYTA DEL PARQUE NACIONAL ÁVILA, SECTORES CERRO EL ÁVILA – LAGUNAZO, VENEZUELA

    Directory of Open Access Journals (Sweden)

    Morales Thalia

    2009-12-01

    Full Text Available Se reportan 29 familias, 74 géneros y 111 especies de musgos para los sectores CerroEl Ávila y Lagunazo, Parque Nacional El Ávila en Caracas, Venezuela. Las familiasPottiaceae, Dicranaceae y Fissidentaceae fueron las más ricas en géneros y especies.A lo largo las seis localidades estudiadas la mayor riqueza de musgos se encontró a1700 m de altura. Del total de especies inventariadas el 60 % corresponden al hábitoacrocárpico, el 43% de los taxones se ubicaron en el sustrato terrestre y la forma devida cespitosa corta (Cc fue la más representativa, con él 44.7% de las especies demusgo. Se adicionan cinco especies a la fl ora muscícola de Venezuela: Rhodobryumroseum (Hedw. Limpr., Pilopogon tiquipayae Herzog, Taxiphyllum taxirameum(Mitt. M. Fleisch., Leskea plumaria Mitt., Bryoerythrophyllum campylocarpum(Müll. Hal. H.A. Crum. Se citan también 22 nuevos registros a la briofl ora de laregión de la Cordillera de la Costa.

  6. Variability of photosynthetic parameters of Pinus sibirica Du Tour needles under changing climatic factors

    Directory of Open Access Journals (Sweden)

    A.P. Zotikova

    2013-12-01

    Full Text Available The air temperature and relative humidity and the intensity of photosynthetically active radiation are the basic ecological factors determining geographical distribution of a species. Wood plant adaptation depends on the intensity of physiological and biochemicalprocesses of plants as a response to changing environmental factors. Investigations to reveal (detect the variability of modification andgenetic components of the photosynthetic parameters in needles of the Siberian cedar (Pinus sibirica Du Tour mountain ecotypes, distributed in central part of the Altai Mountains, were carried out. Also, the survey was extended to some experiments with these ecotypes introduced to mild climate and flat regions from south-western of Siberia. The length and thickness of needles, the size of chloroplasts, content of the photosynthetic pigments, and the functional activity of chloroplastsat the level of photo system II were the evaluated traits. Growing under mountainous conditions (at about 2000m elevation, the two-year-old needles were shorter and thicker and contained very large in size chloroplasts while the content of chlorophylls and carotinoids was twice lower than that in the local ecotype growing in the lowlands. On the other hand, more green and yellow pigments were found in needles of mountain ecotypes planted in the lowlands compared to the local lowland ectype trees. A decrease in pool of the photosynthetic pigments in the highlands ecotypes is probably due to decreased biosynthesis andincreased photo-destruction caused by severe light and temperature conditions. These parameters are likely to be associated withmodifications due to intense insolation, low temperature, ozone concentration, UV radiation, and other negative factors that are morepronounced at high elevation. Despite the large pool of accumulated photosynthetic pigments, the functional activity of chloroplasts in themountain ecotype at the level

  7. Significant heterogeneity in Wolbachia copy number within and between populations of Onchocerca volvulus.

    Science.gov (United States)

    Armoo, Samuel; Doyle, Stephen R; Osei-Atweneboana, Mike Y; Grant, Warwick N

    2017-04-18

    Wolbachia are intracellular bacteria found in arthropods and several filarial nematode species. The filarial Wolbachia have been proposed to be involved in the immunopathology associated with onchocerciasis. Higher Wolbachia-to-nematode ratios have been reported in the savannah-ecotype compared to the forest-ecotype, and have been interpreted as consistent with a correlation between Wolbachia density and disease severity. However, factors such as geographic stratification and ivermectin drug exposure can lead to significant genetic heterogeneity in the nematode host populations, so we investigated whether Wolbachia copy number variation is also associated with these underlying factors. Genomic DNA was prepared from single adult nematodes representing forest and savannah ecotypes sampled from Togo, Ghana, Côte d'Ivoire and Mali. A qPCR assay was developed to measure the number of Wolbachia genome(s) per nematode genome. Next-generation sequencing (NGS) was also used to measure relative Wolbachia copy number, and independently verify the qPCR assay. Significant variation was observed within the forest (range: 0.02 to 452.99; median: 10.58) and savannah (range: 0.01 to 1106.25; median: 9.10) ecotypes, however, no significant difference between ecotypes (P = 0.645) was observed; rather, strongly significant Wolbachia variation was observed within and between the nine study communities analysed (P = 0.021), independent of ecotype. Analysis of ivermectin-treated and untreated nematodes by qPCR showed no correlation (P = 0.869); however, an additional analysis of a subset of the nematodes by qPCR and NGS revealed a correlation between response to ivermectin treatment and Wolbachia copy number (P = 0.020). This study demonstrates that extensive within and between population variation exists in the Wolbachia content of individual adult O. volvulus. The origin and functional significance of such variation (up to ~ 100,000-fold between worms; ~10 to 100

  8. Variability of photosynthetic parameters of Pinus sibirica Du Tour needles under changing climatic factors

    Directory of Open Access Journals (Sweden)

    A.P. Zotikova

    2013-12-01

    Full Text Available The air temperature and relative humidity and the intensity of photosynthetically active radiation are the basic ecological factors determining geographical distribution of a species. Wood plant adaptation depends on the intensity of physiological and biochemicalprocesses of plants as a response to changing environmental factors. Investigations to reveal (detect the variability of modification andgenetic components of the photosynthetic parameters in needles of the Siberian cedar (Pinus sibirica Du Tour mountain ecotypes, distributed in central part of the Altai Mountains, were carried out. Also, the survey was extended to some experiments with these ecotypes introduced to mild climate and flat regions from south-western of Siberia. The length and thickness of needles, the size of chloroplasts, content of the photosynthetic pigments, and the functional activity of chloroplastsat the level of photo system II were the evaluated traits. Growing under mountainous conditions (at about 2000m elevation, the two-year-old needles were shorter and thicker and contained very large in size chloroplasts while the content of chlorophylls and carotinoids was twice lower than that in the local ecotype growing in the lowlands. On the other hand, more green and yellow pigments were found in needles of mountain ecotypes planted in the lowlands compared to the local lowland ectype trees. A decrease in pool of the photosynthetic pigments in the highlands ecotypes is probably due to decreased biosynthesis andincreased photo-destruction caused by severe light and temperature conditions. These parameters are likely to be associated withmodifications due to intense insolation, low temperature, ozone concentration, UV radiation, and other negative factors that are morepronounced at high elevation. Despite the large pool of accumulated photosynthetic pigments, the functional activity of chloroplasts in themountain ecotype at the level

  9. Temperature-driven plasticity in growth cessation and dormancy development in deciduous woody plants: a working hypothesis suggesting how molecular and cellular function is affected by temperature during dormancy induction.

    Science.gov (United States)

    Tanino, Karen K; Kalcsits, Lee; Silim, Salim; Kendall, Edward; Gray, Gordon R

    2010-05-01

    The role of temperature during dormancy development is being reconsidered as more research emerges demonstrating that temperature can significantly influence growth cessation and dormancy development in woody plants. However, there are seemingly contradictory responses to warm and low temperature in the literature. This research/review paper aims to address this contradiction. The impact of temperature was examined in four poplar clones and two dogwood ecotypes with contrasting dormancy induction patterns. Under short day (SD) conditions, warm night temperature (WT) strongly accelerated timing of growth cessation leading to greater dormancy development and cold hardiness in poplar hybrids. In contrast, under long day (LD) conditions, low night temperature (LT) can completely bypass the short photoperiod requirement in northern but not southern dogwood ecotypes. These findings are in fact consistent with the literature in which both coniferous and deciduous woody plant species' growth cessation, bud set or dormancy induction are accelerated by temperature. The contradictions are addressed when photoperiod and ecotypes are taken into account in which the combination of either SD/WT (northern and southern ecotypes) or LD/LT (northern ecotypes only) are separated. Photoperiod insensitive types are driven to growth cessation by LT. Also consistent is the importance of night temperature in regulating these warm and cool temperature responses. However, the physiological basis for these temperature effects remain unclear. Changes in water content, binding and mobility are factors known to be associated with dormancy induction in woody plants. These were measured using non-destructive magnetic resonance micro-imaging (MRMI) in specific regions within lateral buds of poplar under SD/WT dormancing inducing conditions. Under SD/WT, dormancy was associated with restrictions in inter- or intracellular water movement between plant cells that reduces water mobility during dormancy

  10. Insights into the role of differential gene expression on the ecological adaptation of the snail Littorina saxatilis

    Directory of Open Access Journals (Sweden)

    Quesada Humberto

    2010-11-01

    Full Text Available Abstract Background In the past 40 years, there has been increasing acceptance that variation in levels of gene expression represents a major source of evolutionary novelty. Gene expression divergence is therefore likely to be involved in the emergence of incipient species, namely, in a context of adaptive radiation. In this study, a genome-wide expression profiling approach (cDNA-AFLP, validated by quantitative real-time polymerase chain reaction (qPCR were used to get insights into the role of differential gene expression on the ecological adaptation of the marine snail Littorina saxatilis. This gastropod displays two sympatric ecotypes (RB and SU which are becoming one of the best studied systems for ecological speciation. Results Among the 99 transcripts shared between ecotypes, 12.12% showed significant differential expression. At least 4% of these transcripts still displayed significant differences after correction for multiple tests, highlighting that gene expression can differ considerably between subpopulations adapted to alternative habitats in the face of gene flow. One of the transcripts identified was Cytochrome c Oxidase subunit I (COI. In addition, 6 possible reference genes were validated to normalize and confirm this result using qPCR. α-Tubulin and histone H3.3 showed the more stable expression levels, being therefore chosen as the best option for normalization. The qPCR analysis confirmed a higher COI expression in SU individuals. Conclusions At least 4% of the transcriptome studied is being differentially expressed between ecotypes living in alternative habitats, even when gene flow is still substantial between ecotypes. We could identify a candidate transcript of such ecotype differentiation: Cytochrome c Oxidase Subunit I (COI, a mitochondrial gene involved in energy metabolism. Quantitative PCR was used to confirm the differences found in COI and its over-expression in the SU ecotype. Interestingly, COI is involved in the

  11. An Assessment of Genetic Diversity and Drought Tolerance in Argan Tree (Argania spinosa) Populations: Potential for the Development of Improved Drought Tolerance

    Science.gov (United States)

    Chakhchar, Abdelghani; Haworth, Matthew; El Modafar, Cherkaoui; Lauteri, Marco; Mattioni, Claudia; Wahbi, Said; Centritto, Mauro

    2017-01-01

    The argan tree (Argania spinosa) occurs in a restricted area of Southwestern Morocco characterized by low water availability and high evapotranspirative demand. Despite the adaptation of the argan tree to drought stress, the extent of the argan forest has declined markedly due to increased aridity, land use changes and the expansion of olive cultivation. The oil of the argan seed is used for cooking and as the basis for numerous cosmetics. The identification of argan tree varieties with enhanced drought tolerance may minimize the economic losses associated with the decline of the argan forest and constrain the spread of desertification. In this study we collected argan ecotypes from four contrasting habitats and grew them under identical controlled environment conditions to investigate their response to drought. Leaf gas exchange analysis indicated that the argan ecotypes showed a high degree of adaptation to drought stress, maintaining photosynthetic activity at low levels of foliar water content and co-ordinating photosynthesis, stomatal behavior and metabolism. The stomata of the argan trees were highly sensitive to increased leaf to air vapor pressure deficit, representing an adaptation to growth in an arid environment where potential evapotranspiration is high. However, despite originating in contrasting environments, the four argan ecotypes exhibited similar gas exchange characteristics under both fully irrigated and water deficit conditions. Population genetic analyses using microsatellite markers indicated a high degree of relatedness between the four ecotypes; indicative of both artificial selection and the transport of ecotypes between different provinces throughout centuries of management of the argan forest. The majority of genetic variation across the four populations (71%) was observed between individuals, suggesting that improvement of argan is possible. Phenotypic screening of physiological responses to drought may prove effective in identifying

  12. Phenotypic differentiation of the Red Sea gastropods in response to the environmental deterioration: Geometric morphometric approach

    Science.gov (United States)

    Abdelhady, Ahmed Awad

    2016-03-01

    The negative impacts of degradation in the coastal zone of the Red Sea are becoming well known in upper portions of the trophic web (e.g., humans and fish), but are less well known among the benthic primary consumers. In addition, the degree to which heavy metals are entering the trophic web can be better-quantified using macrobenthos. Two-gastropod genera encompassing Echinolittorina subnodosa and Planaxis sulcatus from three different localities on the Egyptian coast of the Red Sea were examined in order to deduce the impact of environmental deterioration on the morphology of shells. The examined sites include clean pristine, slightly polluted, and markedly polluted rocky shores. Phosphate/lead industry is the main source of pollution in this zone. Because landmarks on the rugose Echinolittorina are difficult to define and to ensure finer resolution of the analyses, a newly 'grid-based' landmarks was implemented. Both Canonical Variate Analysis (CVA) and Thin Plate Spline (TPS) were particularly capable to capture and terrace the minor morphological variations accurately. Two phenotypes portioned among the environmentally different populations were recognized and interpreted as ecotypes with many intermediate forms. The first ecotype has a higher spire and smaller aperture and dominating the pristine site North of Marsa Alam, whereas the second ecotype has a globular shell shape with big aperture and dominating the markedly polluted site. The intermediate forms dominating the slightly polluted site. The shape differences are interpreted as an adaptive differentiation to different metal concentrations. As the morphological variation between the two-ecotypes of both taxa is still minors, and both ecotypes occur together with many intermediate forms, the phenotypic divergence stage has not yet accomplished. The gradational shape change among the investigated populations was positively correlated with index of Pollution (IP). As the human activities were the main

  13. Expression de différents écotypes de gombo (Abelmoschus esculentus L. au déficit hydrique intervenant pendant la boutonnisation et la floraison

    Directory of Open Access Journals (Sweden)

    Sawadogo M., Zombre G., Balma D.

    2006-01-01

    Full Text Available Behaviour of different ecotypes of okra (Abelmoschus esculentus L. under water deficit during budding and flowering phases. Despite numerous uses and its well known nutritional value, okra is cultivated on very small surfaces, on surroundings of traditional houses and often in dumping ground. To this little interest are added drought, diseases and pests that generate an important reduction of yield, leading okra to play the last roles in agricultural research programs of the country and this, despite the existence of early maturing ecotypes or resistant to some abiotic constraints. The low rate of improved varieties is the proof that it is necessary to develop strategies for participatory breeding programs that take into account farmers selection criteria including genotypes tolerant or resistant to drastic conditions such as water deficit to periods where the plant is expressing its genetic potential. Six ecotypes obtained through participatory plant breeding process in five agricultural districts of the country have been assessed for the tolerance to the drought occurring during the budding and the flowering phases. Results show that water deficit during budding phase has disastrous consequences for okra plants. The yield declines, and also the length, the number and the weight of fruits. Two types of period of flowering phases of okra plant have been observed: the period which intervenes during the accelerated growth phase of the main stem (type 1 and the one which starts once the growth of main stem begins to decline (type 2; this last type is the most frequently met. Water deficit during the phase of budding causes earlier flowering of type 2 plants and leads to delayed flowering of the type 1 plants. The best variables for discriminating okra ecotypes during water deficit are the relative water content (RWC, the length and the number of fruits. Three ecotypes (V1, V3 and V4 are chosen to be used in breeding program of okra for resistance

  14. An Assessment of Genetic Diversity and Drought Tolerance in Argan Tree (Argania spinosa) Populations: Potential for the Development of Improved Drought Tolerance.

    Science.gov (United States)

    Chakhchar, Abdelghani; Haworth, Matthew; El Modafar, Cherkaoui; Lauteri, Marco; Mattioni, Claudia; Wahbi, Said; Centritto, Mauro

    2017-01-01

    The argan tree (Argania spinosa) occurs in a restricted area of Southwestern Morocco characterized by low water availability and high evapotranspirative demand. Despite the adaptation of the argan tree to drought stress, the extent of the argan forest has declined markedly due to increased aridity, land use changes and the expansion of olive cultivation. The oil of the argan seed is used for cooking and as the basis for numerous cosmetics. The identification of argan tree varieties with enhanced drought tolerance may minimize the economic losses associated with the decline of the argan forest and constrain the spread of desertification. In this study we collected argan ecotypes from four contrasting habitats and grew them under identical controlled environment conditions to investigate their response to drought. Leaf gas exchange analysis indicated that the argan ecotypes showed a high degree of adaptation to drought stress, maintaining photosynthetic activity at low levels of foliar water content and co-ordinating photosynthesis, stomatal behavior and metabolism. The stomata of the argan trees were highly sensitive to increased leaf to air vapor pressure deficit, representing an adaptation to growth in an arid environment where potential evapotranspiration is high. However, despite originating in contrasting environments, the four argan ecotypes exhibited similar gas exchange characteristics under both fully irrigated and water deficit conditions. Population genetic analyses using microsatellite markers indicated a high degree of relatedness between the four ecotypes; indicative of both artificial selection and the transport of ecotypes between different provinces throughout centuries of management of the argan forest. The majority of genetic variation across the four populations (71%) was observed between individuals, suggesting that improvement of argan is possible. Phenotypic screening of physiological responses to drought may prove effective in identifying

  15. Genetic and phenotypic variation along an ecological gradient in lake trout Salvelinus namaycush

    Science.gov (United States)

    Baillie, Shauna M.; Muir, Andrew M.; Hansen, Michael J.; Krueger, Charles Conrad; Bentzen, Paul

    2016-01-01

    BackgroundAdaptive radiation involving a colonizing phenotype that rapidly evolves into at least one other ecological variant, or ecotype, has been observed in a variety of freshwater fishes in post-glacial environments. However, few studies consider how phenotypic traits vary with regard to neutral genetic partitioning along ecological gradients. Here, we present the first detailed investigation of lake trout Salvelinus namaycushthat considers variation as a cline rather than discriminatory among ecotypes. Genetic and phenotypic traits organized along common ecological gradients of water depth and geographic distance provide important insights into diversification processes in a lake with high levels of human disturbance from over-fishing.ResultsFour putative lake trout ecotypes could not be distinguished using population genetic methods, despite morphological differences. Neutral genetic partitioning in lake trout was stronger along a gradient of water depth, than by locality or ecotype. Contemporary genetic migration patterns were consistent with isolation-by-depth. Historical gene flow patterns indicated colonization from shallow to deep water. Comparison of phenotypic (Pst) and neutral genetic variation (Fst) revealed that morphological traits related to swimming performance (e.g., buoyancy, pelvic fin length) departed more strongly from neutral expectations along a depth gradient than craniofacial feeding traits. Elevated phenotypic variance with increasing water depth in pelvic fin length indicated possible ongoing character release and diversification. Finally, differences in early growth rate and asymptotic fish length across depth strata may be associated with limiting factors attributable to cold deep-water environments.ConclusionWe provide evidence of reductions in gene flow and divergent natural selection associated with water depth in Lake Superior. Such information is relevant for documenting intraspecific biodiversity in the largest freshwater lake

  16. Molecular cloning and characterization of novel cystatin gene in leaves Cakile maritima halophyte.

    Science.gov (United States)

    Megdiche, Wided; Passaquet, Chantal; Zourrig, Walid; Zuily Fodil, Yasmine; Abdelly, Chedly

    2009-05-01

    Cakile maritima (Brassicaceae) is a halophyte that thrives on dunes along Mediterranean seashores, with high tolerance to salty and dry environments. We have previously shown that there is great morphological and physiological diversity between ecotypes. We investigated the expression of cysteine protease inhibitor (cystatin) genes in the response to hydric and saline constraints, as cystatins are known to participate in the response to environmental constraints in plants. We isolated, from C. maritime, a new cystatin cDNA (CmC) that encodes a 221 amino acid protein with a calculated molecular mass of 25 kDa. It displays a moderate-to-high amino acid sequence similarity with previously reported phytocystatin genes. The predicted protein is hydrophilic, with only one hydrophobic region, just at its N-terminus, and a calculated isoelectric point of 6.7. Sequence analysis revealed a monocystatin structure with one cystatin-like domain. The predicted protein CmC contains the main conserved motifs characteristic of the plant cystatins, and a putative site of phosphorylation by casein kinase II (TPSD). As some cystatins, it contains a C-terminal extension of 106 amino acid residues, with several conserved cystatin motifs. The expression was constitutive in non-stressed plants, with different levels between the ecotypes, and without apparent relation to the climatic area of origin. Augmented expression was observed under severe salinity except in the ecotype from the arid region. Water deficit also increased CmC expression in two ecotypes, with the highest value observed in the ecotype from the humid region. These results indicate that C. maritima responds to high salinity and water deficit by expressing a cystatin gene that is a known component of defense against abiotic constraints or biotic aggression and survival machinery.

  17. Stochastic population dynamics in populations of western terrestrial garter snakes with divergent life histories.

    Science.gov (United States)

    Miller, David A; Clark, William R; Arnold, Stevan J; Bronikowski, Anne M

    2011-08-01

    Comparative evaluations of population dynamics in species with temporal and spatial variation in life-history traits are rare because they require long-term demographic time series from multiple populations. We present such an analysis using demographic data collected during the interval 1978-1996 for six populations of western terrestrial garter snakes (Thamnophis elegans) from two evolutionarily divergent ecotypes. Three replicate populations from a slow-living ecotype, found in mountain meadows of northeastern California, were characterized by individuals that develop slowly, mature late, reproduce infrequently with small reproductive effort, and live longer than individuals of three populations of a fast-living ecotype found at lakeshore locales. We constructed matrix population models for each of the populations based on 8-13 years of data per population and analyzed both deterministic dynamics based on mean annual vital rates and stochastic dynamics incorporating annual variation in vital rates. (1) Contributions of highly variable vital rates to fitness (lambda(s)) were buffered against the negative effects of stochastic variation, and this relationship was consistent with differences between the meadow (M-slow) and lakeshore (L-fast) ecotypes. (2) Annual variation in the proportion of gravid females had the greatest negative effect among all vital rates on lambda(s). The magnitude of variation in the proportion of gravid females and its effect on lambda(s) was greater in M-slow than L-fast populations. (3) Variation in the proportion of gravid females, in turn, depended on annual variation in prey availability, and its effect on lambda(s) was 4 23 times greater in M-slow than L-fast populations. In addition to differences in stochastic dynamics between ecotypes, we also found higher mean mortality rates across all age classes in the L-fast populations. Our results suggest that both deterministic and stochastic selective forces have affected the evolution of

  18. Stochastic population dynamics in populations of western terrestrial garter snakes with divergent life histories

    Science.gov (United States)

    Miller, David A.; Clark, W.R.; Arnold, S.J.; Bronikowski, A.M.

    2011-01-01

    Comparative evaluations of population dynamics in species with temporal and spatial variation in life-history traits are rare because they require long-term demographic time series from multiple populations. We present such an analysis using demographic data collected during the interval 1978-1996 for six populations of western terrestrial garter snakes (Thamnophis elegans) from two evolutionarily divergent ecotypes. Three replicate populations from a slow-living ecotype, found in mountain meadows of northeastern California, were characterized by individuals that develop slowly, mature late, reproduce infrequently with small reproductive effort, and live longer than individuals of three populations of a fast-living ecotype found at lakeshore locales. We constructed matrix population models for each of the populations based on 8-13 years of data per population and analyzed both deterministic dynamics based on mean annual vital rates and stochastic dynamics incorporating annual variation in vital rates. (1) Contributions of highly variable vital rates to fitness (??s) were buffered against the negative effects of stochastic variation, and this relationship was consistent with differences between the meadow (M-slow) and lakeshore (L-fast) ecotypes. (2) Annual variation in the proportion of gravid females had the greatest negative effect among all vital rates on ?? s. The magnitude of variation in the proportion of gravid females and its effect on ??s was greater in M-slow than L-fast populations. (3) Variation in the proportion of gravid females, in turn, depended on annual variation in prey availability, and its effect on ??s was 4- 23 times greater in M-slow than L-fast populations. In addition to differences in stochastic dynamics between ecotypes, we also found higher mean mortality rates across all age classes in the L-fast populations. Our results suggest that both deterministic and stochastic selective forces have affected the evolution of divergent life

  19. Identification and Quantification of Flavonoids from Two Southern Italian Cultivars of Allium cepa L., Tropea (Red Onion) and Montoro (Copper Onion), and Their Capacity to Protect Human Erythrocytes from Oxidative Stress.

    Science.gov (United States)

    Tedesco, Idolo; Carbone, Virginia; Spagnuolo, Carmela; Minasi, Paola; Russo, Gian Luigi

    2015-06-03

    Onions (Allium cepa) are consumed worldwide and represent an important source of dietary phytochemicals with proven antioxidant properties, such as phenolic acids, flavonoids, thiosulfinates, and anthocyanins. Epidemiological and experimental data suggest that regular consumption of onions is associated with a reduced risk of degenerative disorders. Therefore, it is of interest to investigate the biological properties of different varieties of onions. Here, we characterized for the first time a variety of onion, called Ramata di Montoro (coppery onion from Montoro), grown in a niche area in southern Italy, and compared its phenolic profile and antioxidant properties to a commercial ecotype of red onion, Tropea, also present in southern Italy. An analytical method based on high-performance liquid chromatography coupled with UV detection and mass spectrometry was used to separate and characterize the phenolic fraction (anthocyanins and flavonols) extracted from both coppery and red types. The main compounds detected in the two ecotypes were quercetin and quercetin glucosides, isorhamnetin glucosides, kaempferol glucoside, and, among anthocyanins, cyanidin glucosides. Tropea ecotype onion showed a higher content of flavonols (632.82 mg/kg fresh weight) than Montoro type onion (252.91 mg/kg fresh weight). Accordingly, the antioxidant activity of the former was 2.8-fold higher compared to the latter. More pronounced were the differences existing between the four anthocyanins detected in the two ecotypes, with those in the Tropea ecotype onion present at concentrations 20-230-fold higher than in the Montoro type onion. Both extracts reduced LDL oxidation about 6-fold and protected human erythrocytes from oxidative damage induced by HClO by about 40%. In addition, as a consequence of HClO treatment, glutathione concentration in erythrocytes was reduced about 50% and pretreatment with onion extracts induced a recovery of glutathione level by about 15-22%. Qualitative

  20. Genetic sorting of subordinate species in grassland modulated by intraspecific variation in dominant species.

    Directory of Open Access Journals (Sweden)

    Danny J Gustafson

    Full Text Available Genetic variation in a single species can have predictable and heritable effects on associated communities and ecosystem processes, however little is known about how genetic variation of a dominant species affects plant community assembly. We characterized the genetic structure of a dominant grass (Sorghastrum nutans and two subordinate species (Chamaecrista fasciculata, Silphium integrifolium, during the third growing season in grassland communities established with genetically distinct (cultivated varieties or local ecotypes seed sources of the dominant grasses. There were genetic differences between subordinate species growing in the cultivar versus local ecotype communities, indicating that intraspecific genetic variation in the dominant grasses affected the genetic composition of subordinate species during community assembly. A positive association between genetic diversity of S. nutans, C. fasciculata, and S. integrifolium and species diversity established the role of an intraspecific biotic filter during community assembly. Our results show that intraspecific variation in dominant species can significantly modulate the genetic composition of subordinate species.

  1. Fructan metabolism and changes in fructan composition during cold acclimation in perennial ryegrass

    DEFF Research Database (Denmark)

    Abeynayake, Shamila; Etzerodt, Thomas; Jonavičienė, Kristina;

    2015-01-01

    biomass (top) and the roots, and the transcription of candidate genes involved in fructan metabolism during cold acclimation in perennial ryegrass variety ‘Veyo’ and ecotype ‘Falster’ from distinct geographical origins. We observed changes in fructan composition and induction of low-DP fructans......Perennial ryegrass (Lolium perenne L.) produces high levels of fructans as a mixture of oligomers with different degrees of polymerization (DP). The present study describes the analysis of the compositional changes in the full spectrum of fructan oligomers, fructan distribution between above ground....... The ecotype ‘Falster’, adapted to cold climates, increased total fructan content and produced more fructans (DP˃7) in the roots than the variety ‘Veyo’, adapted to warmer climates suggesting that accumulation of fructans in roots, especially the high-DP fructans as an adaptive trait for plant recovery after...

  2. Environmental regulation of intrinsic photosynthetic capacity: an integrated view.

    Science.gov (United States)

    Demmig-Adams, Barbara; Stewart, Jared J; Adams, William W

    2017-06-01

    Environmental modulation of photosynthetic capacity is reviewed in the context of its assessment and its regulation, genetic differences among species and ecotypes, and links to plant stress tolerance and productivity. Modulation of intrinsic photosynthetic capacity matches investment in photosynthetic components to opportunity for CO2 uptake and productivity in specific environments, with exceptionally high rates during particularly narrow windows of opportunity. Response varies among species and ecotypes and should be evaluated on multiple reference bases as well as chloroplast, leaf, and whole plant scales. Photosynthetic capacity, total foliar vascular transport capacity, and plant sink strength are modulated in concert. Switching among alternative target sinks and alternative foliar vascular architectures may provide avenues for co-optimization of productivity and stress tolerance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Effect of Zinc and Copper Nanoparticles on Drought Resistance of Wheat Seedlings

    Science.gov (United States)

    Taran, Nataliya; Storozhenko, Volodymyr; Svietlova, Nataliia; Batsmanova, Ludmila; Shvartau, Viktor; Kovalenko, Mariia

    2017-01-01

    The effect of a colloidal solution of Cu,Zn-nanoparticles on pro-oxidative/antioxidative balance and content of photosynthetic pigments and leaf area of winter wheat plants of steppe (Acveduc) and forest-steppe (Stolichna) ecotypes was investigated in drought conditions. It has been shown that Cu,Zn-nanoparticles decreased the negative effect of drought action upon plants of steppe ecotype Acveduc. In particular, increased activity of antioxidative enzymes reduced the level of accumulation of thiobarbituric acid reactive substances (TBARS) and stabilized the content of photosynthetic pigments and increased relative water content in leaves. Colloidal solution of Cu,Zn-nanoparticles had less significant influence on these indexes in seedlings of the Stolichna variety under drought.

  4. An EST-based genome scan using 454 sequencing in the marine snail Littorina saxatilis.

    Science.gov (United States)

    Galindo, J; Grahame, J W; Butlin, R K

    2010-09-01

    Genome scans have been used in the studies of ecological speciation to find genomic regions ('outlier loci') showing reduced gene flow between divergent populations/species. High-throughput sequencing ('454') offers new opportunities in this field via transcriptome sequencing. Divergent ecotypes of the marine gastropod Littorina saxatilis represent a good example of incipient ecological speciation. We performed a 454-based genome scan between H and M ecotypes of L. saxatilis from the British Isles using cDNA of pooled individuals. Allele frequencies were calculated for 2454 single nucleotide polymorphisms (SNPs), within 572 contigs, and 7% of loci were detected as outliers. Functional annotation of the contigs containing outlier SNPs showed that they included shell matrix and muscle proteins (lithostathine, mucin, titin), proteins involved in energetic metabolism (arginine kinase, NADH dehydrogenase) and reverse transcriptases. Follow-up investigations into these proteins and unannotated outliers will be a promising route in the study of ecological speciation in L. saxatilis.

  5. Selection on outlier loci and their association with adaptive phenotypes in Littorina saxatilis contact zones.

    Science.gov (United States)

    Hollander, J; Galindo, J; Butlin, R K

    2015-02-01

    A fundamental issue in speciation research is to evaluate phenotypic variation and the genomics driving the evolution of reproductive isolation between sister taxa. Above all, hybrid zones are excellent study systems for researchers to examine the association of genetic differentiation, phenotypic variation and the strength of selection. We investigated two contact zones in the marine gastropod Littorina saxatilis and utilized landmark-based geometric morphometric analysis together with amplified fragment length polymorphism (AFLP) markers to assess phenotypic and genomic divergence between ecotypes under divergent selection. From genetic markers, we calculated the cline width, linkage disequilibrium and the average effective selection on a locus. Additionally, we conducted an association analysis linking the outlier loci and phenotypic variation between ecotypes and show that a proportion of outlier loci are associated with key adaptive phenotypic traits.

  6. Genetic Characterization of Indigenous Rice Varieties in Eastern Himalayan Region of Northeast India

    Institute of Scientific and Technical Information of China (English)

    Baharul Islam CHOUDHURY; Mohammed Latif KHAN; Selvadurai DAYANANDAN

    2014-01-01

    The eastern Himalayan region of Northeast (NE) India is home to a large number of indigenous rice varieties, which are traditionally classified as Oryza sativa subspecies indica, japonica or intermediate types. The classification based on traditional Cheng’s index is often inconclusive due to phenotypic plasticity of morphological characters, which are influenced by environmental conditions. We used molecular markers specific for indica and japonica subspecies to assess the degree of genetic relatedness of indigenous rice varieties in NE India. The results revealed that majority of upland (jum) and glutinous rice varieties, traditionally considered as japonica, were genetically close to the subspecies indica. All varieties of boro ecotype were found to be indica type, and only a few varieties cultivated in lowland and upland areas were japonica type. Some of the lowland varieties of the sali ecotype were intermediate between indica and japonica, and they showed a closer genetic affinity to O. rufipogon.

  7. Ebola virus disease control in West Africa: an ecological, one health approach.

    Science.gov (United States)

    Meseko, Clement Adebajo; Egbetade, Adeniyi Olugbenga; Fagbo, Shamsudeen

    2015-01-01

    The 2013-2015 Ebola Virus Disease outbreak in West Africa had similar nuances with the 1976 outbreaks in Central Africa; both were caused by the Zaire Ebola Virus strain and originated from rural forested communities. The definitive reservoir host of Ebola virus still remains unknown till date. However, from ecological perspective, it is known that the virus first emerged from forest ecotypes interfacing with human activities. As at March 2015, the outbreak has claimed over 9000 lives, which is unprecedented. Though it remains unproved, the primary sources of infection for past and present outbreaks are forest dwelling, human-hunted fauna. Understanding the ecological factors at play in these forest ecotypes where wild fauna interface with human and causing pathogen spill over is important. A broad based One Health approach incorporating these ecological concepts in the control of Ebola Virus Disease can effectively ameliorate or forestall infection now and in the future.

  8. Los musgos (briófita de la región de Santa María-Boyacá (Colombia

    Directory of Open Access Journals (Sweden)

    Aguirre Ceballos Jaime

    2006-06-01

    ítico-terrestres (ocho, doce especies se presentaron en todos los sustratos (epífito-epilíticos-terrestres-materia orgánica en descomposición. En la región de vida tropical la mayoría de las especies fueron epífitas mientras que en la región de vida subandina fueron epífito-epilíticosterrestres-materia orgánica en descomposición. Las formas de crecimiento con mayor representación fueron: cespitosas cortas (24, felpas lisas (17 y felpas rugosas (nueve, tanto para área en general como para cada región de vida. La dominancia de la forma de crecimiento cespitosa cortas y la buena representación de la forma de crecimiento felpas rugosas responde a las condiciones ambientales de alta humedad y alta intensidad lumínica presentes en gran parte de los sectores donde se realizó la colección de los ejemplares. Las felpas lisas siguen en dominancia debido a que gran cantidad de especímenes fueron herborizados en sitos abiertos (senderos o bordes de carretera en donde se presentan condiciones de alta intensidad lumínica y baja humedad relativa que les son favorables.

  9. Mineral accumulation in vegetative and reproductive tissues during seed development in Medicago truncatula

    Directory of Open Access Journals (Sweden)

    Christina B. Garcia

    2015-08-01

    Full Text Available Enhancing nutrient density in legume seeds is one of several strategies being explored to improve the nutritional quality of the food supply. In order to develop crop varieties with increased seed mineral concentration, a more detailed understanding of mineral translocation within the plant is required. By studying mineral accumulation in different organs within genetically diverse members of the same species, it may be possible to identify variable traits that modulate seed mineral concentration. We utilized two ecotypes (A17 and DZA315.16 of the model legume, Medicago truncatula, to study dry mass and mineral accumulation in the leaves, pod walls, and seeds during reproductive development. The pod wall dry mass was significantly different between the two ecotypes beginning at 12 days after pollination, whereas there was no significant difference in the average dry mass of individual seeds between the two ecotypes at any time point. There were also no significant differences in leaf dry mass between ecotypes; however, we observed expansion of A17 leaves during the first 21 days of pod development, while DZA315.16 leaves did not display a significant increase in leaf area. Mineral profiling of the leaves, pod walls, and seeds highlighted differences in accumulation patterns among minerals within each tissue as well as genotypic differences with respect to individual minerals. Because there were differences in the average seed number per pod, the total seed mineral content per pod was generally higher in A17 than DZA315.16. In addition, mineral partitioning to the seeds tended to be higher in A17 pods. These data revealed that mineral retention within leaves and/or pod walls might attenuate mineral accumulation within the seeds. As a result, strategies to increase seed mineral content should include approaches that will enhance export from these tissues.

  10. Compatible host/mycorrhizal fungus combinations for micropropagated sea oats: II. Field evaluation.

    Science.gov (United States)

    Al Agely, Abid; Sylvia, David M

    2008-07-01

    Sea oats (Uniola paniculata L.) are the dominant plant in the pioneer coastal dunes of Florida and are widely used for dune restoration. DNA analysis has revealed significant ecotypic variation among Atlantic and Gulf coast populations of sea oats, but little is known about the diversity of the arbuscular mycorrhizal (AM) communities present in the dune systems. In a prior greenhouse study, we evaluated the functional diversity that exists among the AM fungal communities from divergent Florida dunes and selected effective host/AM fungus combinations for further study. The objective of this study was to evaluate the effect of these compatible combinations on the growth of sea oats planted at Anastasia State Recreation Area (AN) on the Atlantic coast and St. George Island State Park (SG) on the Gulf coast. Micropropagated sea oats from each site were inoculated with AM fungal communities also from AN and SG or a microbial filtrate control. The complete factorial of treatment combinations were grown in the greenhouse for 8 weeks and outplanted to the AN and SG field sites. After 1 year, root colonization was evaluated, and after 2 years, root colonization, shoot and root dry masses, and shoot- and root-P contents were determined. Overall, sea oats planted at AN had greater percent root colonization, shoot dry mass, and shoot-P content than those planted at SG. At AN, the local sea oat ecotype responded more to the fungal community from the same site relative to shoot dry mass and shoot-P content. At SG, the local fungal community produced larger plants with greater P content regardless of the origin of the host. We conclude that sea oat productivity is responsive to AM fungal ecotype as well as host ecotype, and fungal origin should therefore be taken into account when planning sea oat plantings on coastal dunes.

  11. Quantitative divergence of the bacterial root microbiota in Arabidopsis thaliana relatives

    OpenAIRE

    Schlaeppi, K.; Dombrowski, N.; Oter, R. G.; Ver Loren van Themaat, E.; Schulze-Lefert, P

    2014-01-01

    All plants carry distinctive bacterial communities on and inside organs such as roots and leaves, collectively called the plant microbiota. How this microbiota diversifies in related plant species is unknown. We investigated the diversity of the bacterial root microbiota in the Brassicaceae family, including three Arabidopsis thaliana ecotypes, its sister species Arabidopsis halleri and Arabidopsis lyrata, and Cardamine hirsuta. We show that differences in root microbiota profiles between the...

  12. Soybean's Scientific Research and Production Development in Hunan Province These 50 years

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@There are three ecotypes of soybean cultivar in Hunan Province: spring soybean, summer soybean and autumn soybean. Spring soybean has become the leading cultivar used in soybean's commercial production in Hunan these 30-40 years along with the growing improvement of the double-cropping of rice in the province which has reduced the area of the summer and autumn soybean gradually. Soybean produced in the province is almost consumed as processed food.

  13. Linking dynamic phenotyping with metabolite analysis to study natural variation in drought responses of Brachypodium distachyon

    Directory of Open Access Journals (Sweden)

    Lorraine H.C. Fisher

    2016-11-01

    Full Text Available Drought is an important environmental stress limiting the productivity of major crops worldwide. Understanding drought tolerance and possible mechanisms for improving drought resistance is therefore a prerequisite to develop drought-tolerant crops that produce significant yields with reduced amounts of water. Brachypodium distachyon (Brachypodium is a key model species for cereals, forage grasses and energy grasses. In this study, initial screening of a Brachypodium germplasm collection consisting of 138 different ecotypes exposed to progressive drought, highlighted the natural variation in morphology, biomass accumulation and responses to drought stress. A core set of ten ecotypes, classified as being either tolerant, susceptible or intermediate, in response to drought stress, were exposed to mild or severe (respectively 15% and 0% soil water content drought stress and phenomic parameters linked to growth and colour changes were assessed. When exposed to severe drought stress, phenotypic data and metabolite profiling combined with multivariate analysis revealed a remarkable consistency in separating the selected ecotypes into their different pre-defined drought tolerance groups. Increases in several metabolites, including for the phytohormones jasmonic acid and salicylic acid, and TCA-cycle intermediates, were positively correlated with biomass yield and with reduced yellow pixel counts; suggestive of delayed senescence, both key target traits for crop improvement to drought stress. While metabolite analysis also separated ecotypes into the distinct tolerance groupings after exposure to mild drought stress, similar analysis of the phenotypic data failed to do so, confirming the value of metabolomics to investigate early responses to drought stress. The results highlight the potential of combining the analyses of phenotypic and metabolic responses to identify key mechanisms and markers associated with drought tolerance in both the Brachypodium

  14. Genomics, environmental genomics and the issue of microbial species.

    Science.gov (United States)

    Ward, D M; Cohan, F M; Bhaya, D; Heidelberg, J F; Kühl, M; Grossman, A

    2008-02-01

    A microbial species concept is crucial for interpreting the variation detected by genomics and environmental genomics among cultivated microorganisms and within natural microbial populations. Comparative genomic analyses of prokaryotic species as they are presently described and named have led to the provocative idea that prokaryotes may not form species as we think about them for plants and animals. There are good reasons to doubt whether presently recognized prokaryotic species are truly species. To achieve a better understanding of microbial species, we believe it is necessary to (i) re-evaluate traditional approaches in light of evolutionary and ecological theory, (ii) consider that different microbial species may have evolved in different ways and (iii) integrate genomic, metagenomic and genome-wide expression approaches with ecological and evolutionary theory. Here, we outline how we are using genomic methods to (i) identify ecologically distinct populations (ecotypes) predicted by theory to be species-like fundamental units of microbial communities, and (ii) test their species-like character through in situ distribution and gene expression studies. By comparing metagenomic sequences obtained from well-studied hot spring cyanobacterial mats with genomic sequences of two cultivated cyanobacterial ecotypes, closely related to predominant native populations, we can conduct in situ population genetics studies that identify putative ecotypes and functional genes that determine the ecotypes' ecological distinctness. If individuals within microbial communities are found to be grouped into ecologically distinct, species-like populations, knowing about such populations should guide us to a better understanding of how genomic variation is linked to community function.

  15. Phylogeny, Seed Trait, and Ecological Correlates of Seed Germination at the Community Level in a Degraded Sandy Grassland

    OpenAIRE

    Wang, Zhengning; Wang, Lixin; Liu, Zhimin; Li, Yanjuan; Liu, Qingqing; Liu, Bo

    2016-01-01

    Seed germination strongly affects plant population growth and persistence, and it can be dramatically influenced by phylogeny, seed traits, and ecological factors. In this study, we examined the relationships among seed mass, seed shape, and germination percentage (GP), and assessed the extent to which phylogeny, seed traits (seed mass, shape, and color) and ecological factors (ecotype, life form, adult longevity, dispersal type, and onset of flowering) influence GP at the community level. Al...

  16. Comparative Analysis of Polysaccharides from Two Ecological Types of Leymus chinensis

    Institute of Scientific and Technical Information of China (English)

    LI Jing-jing; BI Hong-tao; YAN Ji-hong; SUN Fang; FAN Sha-sha; CAO Gang; ZHOU Yi-fa; CHEN Xi-guang

    2012-01-01

    Leymus chinensis(Trin.) Tzvel.,widely distributed at eastern Eurasian steppe and divided into gray-green type and yellow-green type,has different stress resistance to environment.In the present study,the water-soluble polysaccharides from two ecotypes ofL.chinensis were analyzed in detail,and the differences between polysaccharides from the two ecotypes ofL.chinensis in the yield,monosaccharide composition,molecular weight and structure were clarified.The polysaccharides of L.chinensis were composed of both neutral and acidic polysaccharides.The neutral polysaccharides contained mannose,glucose,galactose,xylose and arabinose,and mainly consisted of β-1,4-Glcp,α-1,3-Galp and α-1,2-Xylp residues.The acidic polysaccharides contained mannose,rhamnose,glucuronic acid,galacturonic acid,glucose,galactose,xylose and arabinose.However,the yields,monosaccharides contents and the molecular weights of the polysaccharides from the two ecotypes of L.chinensis were different.Moreover,the resistance type(gray-green type) of L.chinensis contained a number of α-1,3-Manp and reducing end of β-Glcp residues,and much more O-methyl groups than normal type(yellow-green type) of L.chinensis.The differences of the polysaccharides of the two ecotypes ofL.chinensis might be due to the long-term environmental adaptability of plant,and the differences of the polysaccharides might influence the stress resistance of L.chinensis.

  17. Species status and population structure of the newly described Tursiops australis (the Burrunan dolphin)and Tursiops truncatus (the common bottlenose dolphin)in southern Australian waters, assessed using genetic markers and morphology.

    OpenAIRE

    Charlton, Kate

    2017-01-01

    Taxonomic relationships and affinities within the cetacean genus Tursiops have been plagued with controversy, with historically upwards of 20 species being described and later all synonymised with the common bottlenose dolphin T. truncatus. Numerous studies have demonstrated that Tursiops is polyphyletic. Tursiops truncatus is morphologically and genetically diverse and exhibits distinct 'ecotypes' with coastal/inshore popUlations often distinct from offshore populations. Recently, a 'worldwi...

  18. Effects of Spring Late Frost on Black Seed (Nigella sativa L. under Controlled Conditions

    Directory of Open Access Journals (Sweden)

    T Khorsandi

    2015-04-01

    Full Text Available In many years plant growth strongly affected by late spring frost. In order to evaluate the effects of late frost on Black Seed plants, a factorial experiment based on completely randomized design with three replications was carried out in college of agriculture, Ferdowsi University of Mashhad and five Black Seed ecotypes (Birjsnd, Sabzewar, Ferdows, Gonabad and Neyshabour after two months growth and hardening in natural environment, were exposed to seven temperatures (0, -1.5, -3, -4.5, -6, -7.5 and -9°C in termogradient freezer. For determining cold stress damages, Lethal Temperature (LT for 50% of plants according to the Electrolyte Leakage percentage (LT50el, LT for 50% of plants according to the Survival percentage (LT50su, LT for 50% of plants according to the plant necrose in Test Tube (LT50tt and Reduced Dry Matter Temperature 50 (RDMT50 were measured. Ability of plants for recovery was recorded based on leaf number and leaf area, plant dry weight and cold damage percentage of leaves. According to the LT50tt, LT50su and RDMT50 Black Seed plants can tolerated cold stress in range between -5.7 to -9.0 °C and Sabzewar and Ferdows ecotypes had the most and the least cold tolerance, respectively. At the point of ability of plants for recovery, Ferdows ecotype had the least and Sabzewar and Neyshabour ecotypes had the best plant recovery. Moreover there were high correlations between LT50tt and LT50 based on electrolyte leakage, survival and RDMT50. Electrolyte leakage and visual scoring of cold damage in test tube are rapid methods, so for assessing cold tolerance in plants LT50el and LT50tt indeces may be useful.

  19. Zinc compartmentation in root, transport into xylem, and absorption into leaf cells in the hyperaccumulating species of Sedum alfredii Hance.

    Science.gov (United States)

    Yang, Xiaoe; Li, Tingqiang; Yang, Juncheng; He, Zhenli; Lu, Lingli; Meng, Fanhua

    2006-06-01

    Sedum alfredii Hance can accumulate Zn in shoots over 2%. Leaf and stem Zn concentrations of the hyperaccumulating ecotype (HE) were 24- and 28-fold higher, respectively, than those of the nonhyperaccumulating ecotype (NHE), whereas 1.4-fold more Zn was accumulated in the roots of the NHE. Approximately 2.7-fold more Zn was stored in the root vacuoles of the NHE, and thus became unavailable for loading into the xylem and subsequent translocation to shoot. Long-term efflux of absorbed 65Zn indicated that 65Zn activity was 6.8-fold higher in shoots but 3.7-fold lower in roots of the HE. At lower Zn levels (10 and 100 microM), there were no significant differences in 65Zn uptake by leaf sections and intact leaf protoplasts between the two ecotypes except that 1.5-fold more 65Zn was accumulated in leaf sections of the HE than in those of the NHE after exposure to 100 microM for 48 h. At 1,000 microM Zn, however, approximately 2.1-fold more Zn was taken up by the HE leaf sections and 1.5-fold more 65Zn taken up by the HE protoplasts as compared to the NHE at exposure times >16 h and >10 min, respectively. Treatments with carbonyl cyanide m-chlorophenylhydrazone (CCCP) or ruptured protoplasts strongly inhibited 65Zn uptake into leaf protoplasts for both ecotypes. Citric acid and Val concentrations in leaves and stems significantly increased for the HE, but decreased or had minimal changes for the NHE in response to raised Zn levels. These results indicate that altered Zn transport across tonoplast in the root and stimulated Zn uptake in the leaf cells are the major mechanisms involved in the strong Zn hyperaccumulation observed in S. alfredii H.

  20. Enhanced arsenate reduction by a CDC25-like tyrosine phosphatase explains increased phytochelatin accumulation in arsenate-tolerant Holcus lanatus.

    Science.gov (United States)

    Bleeker, Petra M; Hakvoort, Henk W J; Bliek, Mattijs; Souer, Erik; Schat, Henk

    2006-03-01

    Decreased arsenate [As(V)] uptake is the major mechanism of naturally selected As(V) hypertolerance in plants. However, As(V)-hypertolerant ecotypes also show enhanced rates of phytochelatin (PC) accumulation, suggesting that improved sequestration might additionally contribute to the hypertolerance phenotype. Here, we show that enhanced PC-based sequestration in As(V)-hypertolerant Holcus lanatus is not due to an enhanced capacity for PC synthesis as such, but to increased As(V) reductase activity. Vacuolar transport of arsenite-thiol complexes was equal in both ecotypes. Based on homology with the yeast As(V) reductase, Acr2p, we identified a Cdc25-like plant candidate, HlAsr, and confirmed the As(V) reductase activity of both HlAsr and the homologous protein from Arabidopsis thaliana. The gene appeared to be As(V)-inducible and its expression was enhanced in the As(V)-hypertolerant H. lanatus ecotype, compared with the non-tolerant ecotype. Homologous ectopic overexpression of the AtASR cDNA in A. thaliana produced a dual phenotype. It improved tolerance to mildly toxic levels of As(V) exposure, but caused hypersensitivity to more toxic levels. Arabidopsis asr T-DNA mutants showed increased As(V) sensitivity at low exposure levels and enhanced arsenic retention in the root. It is argued that, next to decreased uptake, enhanced expression of HlASR might act as an additional determinant of As(V) hypertolerance and As transport in H. lanatus.

  1. Plant frequency and distribution on high-lead soil near Leadhills, Lanarkshire

    Energy Technology Data Exchange (ETDEWEB)

    Oxbrow, A.; Moffat, J.

    1979-06-01

    The mean frequency of plants along a transect descending Wanlock Dod, near Leadhills, Lanarkshire, Scotland was determined by quadrat analysis. The results obtained strongly suggested that lead tolerant ecotypes of Agrostis tenuis, Nardus stricta and Potentialla erecta were present above known lead veins. The evidence for Vaccinium myrtillus was less certain. Other species appeared to be affected by soil moisture content, grazing pressure and climatic factors. The areas above known lead veins exhibited a larger diversity of species than the areas between veins.

  2. Genomics of "Candidatus Synechococcus spongiarium", a Cyanobacterial Sponge Symbiont

    Energy Technology Data Exchange (ETDEWEB)

    Slaby, Beate M. [Univ. of Wuerzburg (Germany); Copeland, Alex [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; Woyke, Tanja [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; Hentschel, Ute [Univ. of Wuerzburg (Germany)

    2014-03-21

    Marine sponges (Porifera): ancient metazoans of ecological importance, that produce bioactive secondary metabolites and interact with various microorganisms including cyanobacteria1: Marine Synechococcus spp.: cyanobacteria, important contributors to the global carbon cycle and major primary producers in the oceans2 Ca. S. spongiarum: an ecotype of this genus, widespread and abundant symbiont of various marine sponges around the world3, e.g. Aplysina aerophoba

  3. [PCR-derived technology in gene identification and typing of Yersinia pestis].

    Science.gov (United States)

    Wang, Mei; Tang, Xinyuan; Wang, Zuyun

    2015-01-01

    Application of the PCR-derived technology in gene identification and genotypes of different ecotype Yersinia pestis to make the high-throughput experimental results can reflect the epidemic history and compare the diversity in genome, pathogenicity, so that results from these experiments provide an important basis for clinical diagnosis, treatment and origin. But the experiment should be considered typing ability, practicality, budget and other experimental factors or conditions, because each PCR-derivative technology has advantages and disadvantages.

  4. Mobilization of cadmium by dissolved organic matter in the rhizosphere of hyperaccumulator Sedum alfredii.

    Science.gov (United States)

    Li, Tingqiang; Liang, Chengfeng; Han, Xuan; Yang, Xiaoe

    2013-05-01

    Pot experiments were conducted to investigate the role of dissolved organic matter (DOM) in the Cd speciation in the rhizosphere of hyperaccumulating ecotype (HE) and non-hyperaccumulating ecotype (NHE) of Sedum alfredii and its effects on Cd mobility. After growing HE S. alfredii, the rhizosphere soil solution pH of heavily polluted soil (HPS) and slightly polluted soil (SPS) was reduced by 0.49 and 0.40 units, respectively, due to enhanced DOC derived from root exudation. The total Cd concentration in soil solution decreased significantly but the decrease accounted for less than 1% of the total Cd uptake in the shoots of HE S. alfredii. Visual MINTEQ speciation predicted that Cd-DOM complexes were the dominant Cd species in soil solutions after the growth of S. alfredii for both soils, followed by the free metal Cd(2+) species. However, Cd-DOM complexes fraction in the rhizosphere soil solution of HE S. alfredii (89.1% and 74.6% for HPS and SPS, respectively) were much greater than NHE S. alfredii (82.8% and 64.7% for HPS and SPS, respectively). Resin equilibration experiment results indicated that DOM from the rhizosphere (R-DOM) of both ecotypes of S. alfredii had the ability to form complexes with Cd, whereas the degree of complexation was significantly higher for HE-R-DOM (79-89%) than NHE-R-DOM (63-74%) in the undiluted sample. The addition of HE-R-DOM significantly (P<0.05) increased the solubility of four Cd minerals while NHE-R-DOM was not as effective at the same concentration. It was concluded that DOM in the rhizosphere of hyperaccumulating ecotype of S. alfredii could significantly increase Cd mobility through the formation of soluble DOM-metal complexes.

  5. Final Report: The Rhizosphere Association of the Nitrogen Fixing Bacterial Species Azotobacter Paspali with the Tropical Grass Paspalum Notatum: Specificity of Colonization and Contribution to Plant Nutrition, July 1, 1995 - February 14, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Christina K.

    1997-02-14

    The nitrogen fixing bacterium azotobacter paspali was first isolated from the roots of the sub-tropical grass, palpium notatum, and added to the clenus in 1996, by Dr. J. Dobereiner (Brazil). It is mentioned that this root association bacteria shows remarkable signs of host-plant specificity to one eco-type of this grass. This specificity is rare in non-symbiotic plant microbe interactions so far identified.

  6. Historical Biogeography of the Marine Snail Littorina saxatilis Inferred from Haplotype and Shell Morphology Evolution in NW Spain.

    Science.gov (United States)

    Tirado, Terencia; Saura, María; Rolán-Alvarez, Emilio; Quesada, Humberto

    2016-01-01

    The marine snail Littorina saxatilis exhibits extreme morphological variation between and within geographical regions and represents an excellent model for assessing local adaptation. Previous studies support the hypothesis of parallel evolution in sympatry of two morphologically different ecotypes (named as RB and SU) that co-inhabit different habitats from Galician rocky shores (NW Spain), and which are interrupted by sheltered areas inhabited by a different morph never studied before (named as SRB). Here, we use morphological and mitochondrial DNA (mtDNA) sequence data to test hypotheses on the origin and diversification of SRB snails and to assess their evolutionary relationships with RB and SU ecotypes. Our results show that the SRB morph displays the largest size and shell elongation and the smallest relative shell aperture, representing an extreme type of the RB vs. SU polymorphism, which has been linked to adaptation to sheltered ecological factors. Phylogenetic analysis shows that the SRB morph shares ancestry with RB and SU ecotypes, rejecting the hypothesis that the SRB morph marks relict populations from which these ecotypes evolved in Galician coasts. Our data support that genetic differentiation among SRB, RB and SU morphs results from a general pattern of restricted gene flow and isolation by distance linked to the colonization of Galician coasts by two independent mtDNA lineages, rather than from a random fragmentation of the initial distributional range. Therefore, the confinement of distinct lineages to specific geographical areas denote evident limits to the distances these snails can disperse. Morphological analysis indicates no association between mtDNA lineage and a specific morphotype, and suggests the independent gain of convergent morphological patterns within each mtDNA lineage in populations occupying contrasting habitats following the colonization of Galician coasts.

  7. Biochemical Genetic Mechanism and QTLs of Early Maturing without Yield Loss in Short-season Upland Cotton (Gossypium hirsutum L.)

    Institute of Scientific and Technical Information of China (English)

    SONG Mei-zhen; YU Shu-xun; FAN Shu-li

    2008-01-01

    @@ The short season cotton (SSC) was important Upland plant ecotype (Gossypium hirsutum L.).The growth of SSC was very short that is 105~110 days (after planting).SSC could increase plant index and farmer incomes on the same soil in one year.However,there was a contradiction between the early maturing and high-yield potential of SSC varieties that restrict SSC development.The SSC varieties often exhibited premature senescence.

  8. The effect of the weight of cloves on the growth and the yield of fall-planted garlic

    Directory of Open Access Journals (Sweden)

    Renata Nurzyńska-Wierdak

    2013-12-01

    Full Text Available In three years trials (1990-1993 the effect of diameter of bulbilson growth and yield of local garlic ecotype R was studied. Nine size classes of bulbils were investigated. Significant effect of diameter of bulbils on biometric propeities and yield of local garlic was found out. The plants grown from big bulbils gave higher and better quality yield then those grown from smaller bulbils. There was no difference in yield of plants grown from big and medium bulbils.

  9. Caracterización de la macrofauna edáfica en sistemas de producción intensiva de césped

    Directory of Open Access Journals (Sweden)

    Wendy Ramírez

    Full Text Available Se realizó una investigación con el objetivo de evaluar el comportamiento de la macrofauna edáfica en áreas de la finca de producción intensiva de césped, en la Estación Experimental de Pastos y Forrajes Indio Hatuey. Se evaluaron tres sistemas, con diferentes años de explotación y tres réplicas por sistema: S1: suelos con diez años o más de explotación intensiva; S2: suelos con cuatro años de explotación; y S3: suelos de condición estándar o de referencia, en los que se establecerán las parcelas para la producción intensiva de césped. En sentido general, la composición taxonómica de la macrofauna edáfica fue similar en los sistemas evaluados, y existieron diferencias en cuanto a la diversidad y equitatividad de los órdenes. Los sistemas más perturbados (S1 y S2 fueron los de menor diversidad taxonómica, con cinco unidades taxonómicas (ut, debido al monocultivo continuado de gramíneas cespitosas. Los órdenes de mayor representación en el S1 fueron Coleoptera (38,63 % y Haplotaxida (31,81 %; en el S2, Coleoptera (52,63 % y Haplotaxida (28,94 %; y en el S3, Haplotaxida (34,48 % y Lepidoptera (12,93 %. Estos resultados evidencian el potencial de la macrofauna edáfica como indicador de la calidad del suelo, y su sensibilidad ante las perturbaciones causadas por la intensidad en el uso y manejo del suelo.

  10. Floristic Development Patterns in a Restored Elk River Estuarine Marsh, Grays Harbor, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Thom, Ronald M.(BATTELLE (PACIFIC NW LAB)); Zeigler, Robert (Washington State Department of Fish and Wildlife); Borde, Amy B.(BATTELLE (PACIFIC NW LAB))

    2002-09-15

    We describe the changes in the floral assemblage in a salt marsh after reconnection to estuarine tidal inundation. The Elk River marsh in Grays Harbor, Washington, was opened to tidal flushing in 1987 after being diked for approximately 70 years. The freshwater pasture assemblage dominated by Phalarais arundinacea (reed canary grass) converted to low salt marsh vegetation within 5 years, with the major flux in species occurring between years 1 and 4. The system continued to develop through the 11-year post-breach monitoring period, although change after year 6 was slower than in previous years. The assemblage resembles a low salt marsh community dominated by Distichlis spicata (salt grass) and Salicornia virginica (pickleweed). Because of subsidence of the system during the period of breaching, the restored system remains substantially different from the Deschamsia cespitosa (tufted hairgrass)-dominated reference march. Use of a similarity index to compare between years and also between reference and restored marshes in the same year revealed that similarity in floral composition between year 0 and subsequent years decreased with time. However, there was a period of dramatic dissimilarity during years 1 to 3 when the system was rapidly changing from a freshwater to estuarine condition. Similarity values between the reference and restored system generally increased with time. Somewhat surprisingly, the reference marsh showed considerable between-year variation in similarity, which indicated substantial year-to-year variability in species composition. Based on accretion rate date from previous studies we predict that full recovery of the system would take between 75 and 150 years.

  11. Inundation, vegetation, and sediment effects on litter decomposition in Pacific Coast tidal marshes

    Science.gov (United States)

    Janousek, Christopher; Buffington, Kevin J.; Guntenspergen, Glenn R.; Thorne, Karen M.; Dugger, Bruce D.; Takekawa, John Y.

    2017-01-01

    The cycling and sequestration of carbon are important ecosystem functions of estuarine wetlands that may be affected by climate change. We conducted experiments across a latitudinal and climate gradient of tidal marshes in the northeast Pacific to evaluate the effects of climate- and vegetation-related factors on litter decomposition. We manipulated tidal exposure and litter type in experimental mesocosms at two sites and used variation across marsh landscapes at seven sites to test for relationships between decomposition and marsh elevation, soil temperature, vegetation composition, litter quality, and sediment organic content. A greater than tenfold increase in manipulated tidal inundation resulted in small increases in decomposition of roots and rhizomes of two species, but no significant change in decay rates of shoots of three other species. In contrast, across the latitudinal gradient, decomposition rates of Salicornia pacifica litter were greater in high marsh than in low marsh. Rates were not correlated with sediment temperature or organic content, but were associated with plant assemblage structure including above-ground cover, species composition, and species richness. Decomposition rates also varied by litter type; at two sites in the Pacific Northwest, the grasses Deschampsia cespitosa and Distichlis spicata decomposed more slowly than the forb S. pacifica. Our data suggest that elevation gradients and vegetation structure in tidal marshes both affect rates of litter decay, potentially leading to complex spatial patterns in sediment carbon dynamics. Climate change may thus have direct effects on rates of decomposition through increased inundation from sea-level rise and indirect effects through changing plant community composition.

  12. Saffron (Crocus sativus L., a monomorphic or polymorphic species?

    Directory of Open Access Journals (Sweden)

    Zahra Nemati

    2014-07-01

    Full Text Available Saffron (Crocus sativus L. which contains exceptional anti-cancer properties is presently the world's most expensive spice. Iran is known as the original habitat of Crocus L. and a significant source of high-quality cultivated saffron production and export. Considering the importance of this species, we used 27 microsatellite markers to assess molecular variability and discriminating capacity of markers regarding their effectiveness in establishing genetic relationships in Iranian Crocus ecotypes. Thirty eight Iranian cultivated saffron ecotypes and 29 wild allies were evaluated in this research. The results from molecular analyses, including a molecular phylogenetic network and RB analysis, revealed two major groups and five subgroups, regardless of their geographical origins. Also, the results showed a clear distinction between C. sativus and other species of Crocus genus, taking into account their close relationship with C. speciosus and C. hausknechtii, which are assumed to be the two closest relatives of Iranian cultivated saffron among species studied. In this paper, we observed for the first time extensive genetic diversity among Iranian C. sativus despite their asexual reproduction. Considering suitable climatic conditions in Iran for cultivating saffron and the country’s leading high-quality production of Crocus sativus worldwide, studies on great genetic variability among Iranian C. sativus ecotypes as well as wild relatives native to Iran will further highlight the value of this crop. In addition, our results provide valuable information for genetic improvement, reduction of strong genetic erosion, and conservation of costly heritable resources of C. sativus in future breeding programs.

  13. A molecular analysis of the patterns of genetic diversity in local chickens from western Algeria in comparison with commercial lines and wild jungle fowls.

    Science.gov (United States)

    Mahammi, F Z; Gaouar, S B S; Laloë, D; Faugeras, R; Tabet-Aoul, N; Rognon, X; Tixier-Boichard, M; Saidi-Mehtar, N

    2016-02-01

    The objectives of this study were to characterize the genetic variability of village chickens from three agro-ecological regions of western Algeria: coastal (CT), inland plains (IP) and highlands (HL), to reveal any underlying population structure, and to evaluate potential genetic introgression from commercial lines into local populations. A set of 233 chickens was genotyped with a panel of 23 microsatellite markers. Geographical coordinates were individually recorded. Eight reference populations were included in the study to investigate potential gene flow: four highly selected commercial pure lines and four lines of French slow-growing chickens. Two populations of wild red jungle fowls were also genotyped to compare the range of diversity between domestic and wild fowls. A genetic diversity analysis was conducted both within and between populations. Multivariate redundancy analyses were performed to assess the relative influence of geographical location among Algerian ecotypes. The results showed a high genetic variability within the Algerian population, with 184 alleles and a mean number of 8.09 alleles per locus. The values of heterozygosity (He and Ho) ranged from 0.55 to 0.62 in Algerian ecotypes and were smaller than values found in Jungle fowl populations and higher than values found in commercial populations. Although the structuring analysis of genotypes did not reveal clear subpopulations within Algerian ecotypes, the supervised approach using geographical data showed a significant (p Algeria are characterized by a high genetic diversity and must be safeguarded as an important reservoir of genetic diversity.

  14. The ecohealth assessment and ecological restoration division of urban water system in Beijing

    Science.gov (United States)

    Liu, J.; Ma, M.; Zhang, F.; Yang, Z.; Domagalski, J.

    2009-01-01

    Evaluating six main rivers and six lakes in Beihuan water system (BWS) and diagnosing the limiting factors of eco-health were conducted for the ecohealth assessment and ecological restoration division of urban water system (UWS) for Beijing. The results indicated that Jingmi River and Nanchang River were in a healthy state, the degree of membership to unhealthy were 0.358, 0.392, respectively; while Yongding River, Beihucheng River, Liangma River, Tongzi River and six lakes were in an unhealthy state, their degree of membership to unhealthy were between 0.459 and 0.927. The order of that was Liangma > Beihucheng > Tongzi > Yongding > six lakes > Jingmi > Nanchang, in which Liangma Rivers of that was over 0.8. The problems of Rivers and lakes in BWS are different. Jingmi River and Nanchang River were ecotype limiting; Yongding River, Tongzi River and six lakes were water quality and ecotype limiting. Beihucheng River and Liangma River were water quantity, water quality and ecotype limiting. BWS could be divided into 3 restoration divisions, pollution control division including Yongding River, Tongzi River and six lakes; Jingmi River and Nanchang River were ecological restoration zone, while Beihucheng River and Liangma River were in comprehensive improvement zone. Restoration potentiality of Jingmi River and Nanchang River were higher, and Liangma River was hardest to restore. The results suggest a new idea to evaluate the impact of human and environmental factors on UWS. ?? Springer Science+Business Media, LLC 2009.

  15. ASPECTOS ANATÓMICOS DE LA FORMACIÓN Y CRECIMIENTO DEL FRUTO DE UCHUVA Physalis peruviana (Solanaceae Anatomic Aspects of Formation and Growth of the Cape Gooseberry Fruit Physalis peruviana (Solanaceae

    Directory of Open Access Journals (Sweden)

    MANUEL FERNANDO MAZORRA

    2006-06-01

    Full Text Available Se observaron y describieron los cambios anatómicos en estructuras reproductivas, botón a fruto maduro, se establecieron los estados fenológicos y el desarrollo estructural del fruto a través del tiempo en frutos de uchuva ecotipo Colombia. Esta investigación se realizó en un huerto comercial de uchuva (Physalis peruviana localizado en el municipio de Granada, Cundinamarca, Colombia. El estudio confirmó que anatómicamente los frutos de uchuva ecotipo Colombia y de tipo ruderal son similares, lo que demuestra la ausencia de cambios anatómicos apreciables que expliquen el mayor tamaño de los frutos del ecotipo Colombia.The anatomical changes in reproductive structures were observed and described frrom button to mature fruit and the phenological states and the structural development of the Cape gooseberry fruit, ecotype Colombia, were established settled down. This investigation was made in a commercial Cape gooseberry (Physalis peruviana orchard located in the municipality of Granada, Cundinamarca, Colombia. The study confirmed that anatomically the Cape gooseberry fruits, ecotype Colombia, and ruderal type are similar, which demonstrates the absence of appreciable anatomical changes that explain the greater size of the fruits of ecotype Colombia.

  16. Aluminum-Tolerant Pisolithus Ectomycorrhizas Confer Increased Growth, Mineral Nutrition, and Metal Tolerance to Eucalyptus in Acidic Mine Spoil

    Directory of Open Access Journals (Sweden)

    Louise Egerton-Warburton

    2015-01-01

    Full Text Available Ectomycorrhizal fungi (ECM may increase the tolerance of their host plants to Al toxicity by immobilizing Al in fungal tissues and/or improving plant mineral nutrition. Although these benefits have been demonstrated in in vitro (pure culture or short-term nutrient solution (hydroponic experiments, fewer studies have examined these benefits in the field. This study examined the growth, mineral nutrition, and Al levels in two Eucalyptus species inoculated with three Pisolithus ecotypes that varied in Al tolerance (in vitro and grown in mine spoil in the greenhouse and field. All three ecotypes of Pisolithus improved Eucalyptus growth and increased host plant tolerance to Al in comparison to noninoculated plants. However, large variations in plant growth and mineral nutrition were detected among the Pisolithus-inoculated plants; these differences were largely explained by the functional properties of the Pisolithus inoculum. Seedlings inoculated with the most Al-tolerant Pisolithus inoculum showed significantly higher levels of N, P, Ca, Mg, and K and lower levels of Al than seedlings inoculated with Al-sensitive ecotypes of Pisolithus. These findings indicate an agreement between the fungal tolerance to Al in vitro and performance in symbiosis, indicating that both ECM-mediated mineral nutrient acquisition and Al accumulation are important in increasing the host plant Al tolerance.

  17. Ecological plasticity of Trichoderma fungi in leached chernozem

    Science.gov (United States)

    Svistova, I. D.; Senchakova, T. Yu.

    2010-03-01

    The autecological properties of Trichoderma fungi ecotypes isolated from the leached chernozem of the forest-steppe zone of the European part of Russia have been studied. We were the first who carried out the complex study of the synecological relations of micromycetes of such kinds in a system including the soil, microbial community, and plants, i.e., their relations with soil saprotrophic fungi, bacteria, actinomycetes, plants, and pathogenic fungi. It was shown that the ecological plasticity of the Trichoderma genus in the soil of this zone is determined by its growth rate, the optimum pH and temperature, the biosynthesis of extracellular hydrolytic enzymes, the biological action of mycotoxins, and the ability for parasitism. The efficiency of the introduction of Trichoderma species typical and atypical for the leached chernozem into this soil and their influence on the structure of the microbial community were evaluated. The T. pseudokoningii ecotype, which produces cellulolytic enzymes, is very promising for industrial biotechnology, and the T. harzianum ecotype can be used in soil biotechnology for the biocontrol of chernozem. The addition of a commercial trichodermin preparation into the chernozem damages the structure of its microbial community.

  18. Is the vertical transmission of Neotyphodium lolii in perennial ryegrass the only possible way to the spread of endophytes?

    Science.gov (United States)

    Wiewióra, Barbara; Żurek, Grzegorz; Pańka, Dariusz

    2015-01-01

    Endophytic fungi live their whole life within host tissues usually without any visible symptoms. Their vertical transmission (seed-plant-seed) has been well described and documented. However, horizontal transmission (plant-plant) needs more clarification. The aim of this study was to assess the extent to which endophytes move vertically in ecotypes of perennial ryegrass and whether there is evidence for the horizontal transmission of endophytes. Ecotypes from grasslands in Poland were collected in the form of living plants and used for vertical transmission analysis. Plants, the seed collected from these plants and plants grown from this collected seed were tested for endophytic infection. Provided that all produced seeds were viable and able to germinate and produce seedlings, the vertical transmission of Neotyphodium endophytes in perennial ryegrass ecotypes was nearly complete. For the horizontal transmission experiment, endophyte-hosting plants (E+) and endophyte-free plants (E-) of four cultivars were planted in the field in close proximity on small plots that were frequently mown. These studies revealed that after 7 months of growth next to E+ plants, the characteristic Neotyphodium spp. mycelia were found in E- plants, which was especially true for plants growing in close proximity to the infected plants. The occurrence of horizontal transmission of endophytes has not been previously demonstrated.

  19. Is the vertical transmission of Neotyphodium lolii in perennial ryegrass the only possible way to the spread of endophytes?

    Directory of Open Access Journals (Sweden)

    Barbara Wiewióra

    Full Text Available Endophytic fungi live their whole life within host tissues usually without any visible symptoms. Their vertical transmission (seed-plant-seed has been well described and documented. However, horizontal transmission (plant-plant needs more clarification. The aim of this study was to assess the extent to which endophytes move vertically in ecotypes of perennial ryegrass and whether there is evidence for the horizontal transmission of endophytes. Ecotypes from grasslands in Poland were collected in the form of living plants and used for vertical transmission analysis. Plants, the seed collected from these plants and plants grown from this collected seed were tested for endophytic infection. Provided that all produced seeds were viable and able to germinate and produce seedlings, the vertical transmission of Neotyphodium endophytes in perennial ryegrass ecotypes was nearly complete. For the horizontal transmission experiment, endophyte-hosting plants (E+ and endophyte-free plants (E- of four cultivars were planted in the field in close proximity on small plots that were frequently mown. These studies revealed that after 7 months of growth next to E+ plants, the characteristic Neotyphodium spp. mycelia were found in E- plants, which was especially true for plants growing in close proximity to the infected plants. The occurrence of horizontal transmission of endophytes has not been previously demonstrated.

  20. Adaptation of C4 Bioenergy Crop Species to Various Environments within the Southern Great Plains of USA

    Directory of Open Access Journals (Sweden)

    Sumin Kim

    2017-01-01

    Full Text Available As highly productive perennial grasses are evaluated as bioenergy feedstocks, a major consideration is biomass yield stability. Two experiments were conducted to examine some aspects of yield stability for two biofuel species: switchgrass (Panicum vigratum L. and Miscanthus x giganteus (Mxg. Biomass yields of these species were evaluated under various environmental conditions across the Southern Great Plains (SGP, including some sites with low soil fertility. In the first experiment, measured yields of four switchgrass ecotypes and Mxg varied among locations. Overall, plants showed optimal growth performance in study sites close to their geographical origins. Lowland switchgrass ecotypes and Mxg yields simulated by the ALMANAC model showed reasonable agreement with the measured yields across all study locations, while the simulated yields of upland switchgrass ecotypes were overestimated in northern locations. In the second experiment, examination of different N fertilizer rates revealed switchgrass yield increases over the range of 0, 80, or 160 kg N ha−1 year−1, while Mxg only showed yield increases between the low and medium N rates. This provides useful insights to crop management of two biofuel species and to enhance the predictive accuracy of process-based models, which are critical for developing bioenergy market systems in the SGP.

  1. Influence of EDTA on lead transportation and accumulation by Sedum alfredii Hance

    Energy Technology Data Exchange (ETDEWEB)

    Liu Dan [Zhejiang Univ., Hangzhou (China). Key Lab. of Environmental Remediation and Ecosystem Health, Ministry of Education; Zhejiang Forestry College, Lin' an (China). School of Tourism and Health; Li Ting-Qiang; Yang Xiao-E; Islam, E.; Jin Xiao-Fen; Mahmood, Q. [Zhejiang Univ., Hangzhou (China). Key Lab. of Environmental Remediation and Ecosystem Health, Ministry of Education

    2007-09-15

    Hydroponics and pot experiments were conducted to study the effects of ethylenediaminetetraacetic acid (EDTA) on Pb transportation and accumulation by two contrasting ecotypes of Sedum alfredii Hance. In hydroponics experiments, the accumulating ecotype (AE) showed more ability to tolerate Pb toxicitycompared with the non-accumulating ecotype (NAE). When treated with equimolar mixtures of EDTA and Pb, maximum Pb accumulation occurred without any phytotoxicity symptoms. Pot experiments with Pb contents of 400 mg kg{sup -1} showed that 5 mm EDTA is the optimum dose for the phytoextraction of soils contaminated with relatively low Pb levels; in contrast, increasing EDTA addition resulted in increased Pb accumulation in the shoots of AE in soils with high Pb content (1200 mg kg{sup -1}). The post-harvest effects of EDTA on available Pb were strong compared with those without addition of EDTA (CK). Within the initial 7 days almost no differences of water-soluble Pb were noted in soils contaminated with both levels of Pb but after 2 weeks, water-soluble Pb started to decrease significantlycompared with before. Considering the toxicity and biodegradability of synthetic chelators, it can be concluded that the chelate-assisted technique is more suitable for soils contaminated with low Pb levels and to avoid environment risks; a suitable dose of chelators must be considered before application. (orig.)

  2. Genetic variation and host-parasite specificity of Striga resistance and tolerance in rice: the need for predictive breeding.

    Science.gov (United States)

    Rodenburg, Jonne; Cissoko, Mamadou; Kayongo, Nicholas; Dieng, Ibnou; Bisikwa, Jenipher; Irakiza, Runyambo; Masoka, Isaac; Midega, Charles A O; Scholes, Julie D

    2017-02-13

    The parasitic weeds Striga asiatica and Striga hermonthica cause devastating yield losses to upland rice in Africa. Little is known about genetic variation in host resistance and tolerance across rice genotypes, in relation to virulence differences across Striga species and ecotypes. Diverse rice genotypes were phenotyped for the above traits in S. asiatica- (Tanzania) and S. hermonthica-infested fields (Kenya and Uganda) and under controlled conditions. New rice genotypes with either ecotype-specific or broad-spectrum resistance were identified. Resistance identified in the field was confirmed under controlled conditions, providing evidence that resistance was largely genetically determined. Striga-resistant genotypes contributed to yield security under Striga-infested conditions, although grain yield was also determined by the genotype-specific yield potential and tolerance. Tolerance, the physiological mechanism mitigating Striga effects on host growth and physiology, was unrelated to resistance, implying that any combination of high, medium or low levels of these traits can be found across rice genotypes. Striga virulence varies across species and ecotypes. The extent of Striga-induced host damage results from the interaction between parasite virulence and genetically determined levels of host-plant resistance and tolerance. These novel findings support the need for predictive breeding strategies based on knowledge of host resistance and parasite virulence.

  3. Growth and development in Arabidopsis thaliana through an entire life cycle under simulated microgravity conditions on a clinostat.

    Science.gov (United States)

    Miyamoto, K; Yamamoto, R; Fujii, S; Soga, K; Hoson, T; Shimazu, T; Masuda, Y; Kamisaka, S; Ueda, J

    1999-12-01

    The effects of simulated microgravity conditions produced by a horizontal clinostat on the entire life cycle of Arabidopsis thaliana ecotype Columbia and Landsberg erecta were studied. Horizontal clinorotation affected little germination of seeds, growth and development of rosette leaves and roots during early vegetative growth stage, and the onset of the bolting of inflorescence axis and flower formation in reproductive growth stage, although it suppressed elongation of inflorescence axes. The clinorotation substantially reduced the numbers of siliques and seeds in Landsberg erecta, and completely inhibited seed production in Columbia. Seeds produced in Landsberg erecta on the clinostat were capable of germinating and developing rosette leaves normally on the ground. On the other hand, growth of pin formed mutant (pin/pin) of Arabidopsis ecotype Enkheim, which has a unique structure of inflorescence axis with no flower and extremely low levels of auxin polar transport activity, was inhibited and the seedlings frequently died during vegetative stage on the clinostat. Seed formation and inflorescence growth of the seedlings with normal shape (pin/+ or +/+) were also suppressed on the clinostat. These results suggest that the growth and development of Arabidopsis, especially in reproductive growth stage, is suppressed under simulated microgravity conditions on a clinostat. To complete the life cycle probably seems to be quite difficult, although it is possible in some ecotypes.

  4. Cadmium hyperaccumulation protects Thlaspi caerulescens from leaf feeding damage by thrips (Frankliniella occidentalis).

    Science.gov (United States)

    Jiang, R F; Ma, D Y; Zhao, F J; McGrath, S P

    2005-09-01

    Metal hyperaccumulation has been proposed as a plant defensive strategy. Here, we investigated whether cadmium (Cd) hyperaccumulation protected Thlaspi caerulescens from leaf feeding damage by thrips (Frankliniella occidentalis). Two ecotypes differing in Cd accumulation, Ganges (high) and Prayon (low), were grown in compost amended with 0-1000 mg Cd kg(-1) in two experiments under glasshouse conditions. F2 and F3 plants from the Prayon x Ganges crosses were grown with 5 mg Cd kg(-1). Plants were naturally colonized by thrips and the leaf feeding damage index (LFDI) was assessed. The LFDI decreased significantly with increasing Cd in both ecotypes, and correlated with shoot Cd concentration in a log-linear fashion. Prayon was more attractive to thrips than Ganges, but the ecotypic difference in the LFDI was largely accounted for by the shoot Cd concentration. In the F2 and F3 plants, the LFDI correlated significantly and negatively with shoot Cd, but not with shoot zinc (Zn) or sulphur (S) concentrations. We conclude that Cd hyperaccumulation deters thrips from feeding on T. caerulescens leaves, which may offer an adaptive benefit to the plant.

  5. Alkaline phosphatase activity and the phosphorus mineralization rate of Lake Taihu

    Institute of Scientific and Technical Information of China (English)

    GAO; Guang; ZHU; Guangwei; QIN; Boqiang; CHEN; Jun

    2006-01-01

    The phosphorus fractions, the alkaline phosphatase activity (APA) and other water chemical parameters were concomitantly monitored from April 2003 to October 2004 in different ecotype sites of Lake Taihu. During the stages of algae growth, the phosphorus fractions and their relationships with APA in different ecotype sites were discussed and the phosphorus mineralization rate was calculated. In the water of Lake Taihu, most of the phosphorus (70.2%) could be attributed to the suspended particulate phosphorus, while the dissolved reactive phosphorus (DRP) seems to contribute less than 7%. About 58% of the total phosphorus, however, can be hydrolyzed as inorganic phosphate to compensate for phosphorus deficiency of algae and bacteria growth. During the different algae growth stages, the APA and its Kinetic parameters were varied significantly between different ecotype sites of Lake Taihu. This trend is also visible by comparing the phosphorus mineralization rate,and the most rapidly phosphorus turnover time is only several minutes. The fast recycle of phosphorus can, to some extent, be explained that the phosphorus source of algal blooms. The phytoplankton seems to compensate for phosphorus deficiency by using the alkaline phosphatase to hydrolyze phosphomonoesters.

  6. Complexation with dissolved organic matter and mobility control of heavy metals in the rhizosphere of hyperaccumulator Sedum alfredii.

    Science.gov (United States)

    Li, Tingqiang; Tao, Qi; Liang, Chengfeng; Shohag, M J I; Yang, Xiaoe; Sparks, Donald L

    2013-11-01

    The complexation of Zn, Cd and Pb with dissolved organic matter (DOM) in the rhizosphere of hyperaccumulating ecotype (HE) and a non-hyperaccumulating ecotype (NHE) of Sedum alfredii was measured using resin equilibration method. After the growth of HE S. alfredii, the rhizosphere soil pH was reduced by 0.27-0.33 units, due to enhanced DOM derived from root exudation. For both ecotypes of S. alfredii, the fraction of free metal as a percentage of soluble metal varied from 22.1 to 42.5% for Zn(2+), from 8.1 to 15.5% for Cd(2+), and from 4.5 to 10.4% for Pb(2+). Resin equilibration experiment results indicated that HE-DOM had greater ability to form complexes with Zn, Cd and Pb than NHE-DOM, Visual MINTEQ model gave excellent predictions of the complexation of Zn and Cd by DOM (R(2) > 0.97). DOM in the rhizosphere of HE S. alfredii could significantly increase metal mobility through the formation of soluble DOM-metal complexes.

  7. Clustering of Pathogen-Response Genesin the Genome of Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Olga A. Postnikova; Natalia Y. Minakova; Alexander M. Boutanaev; Lev G. Nemchinov

    2011-01-01

    Previously,we used heterologous expressed sequence tag (EST) mapping to generate a profile of 4 935pathogen-response genes of Arabidopsis thaliana.In this work,we performed a computer analysis of this profile,revealing 1 594 non-homologous clustered genes distributed among all A.thaliana chromosomes,whose co-regulation may be related to host responses to pathogens.To supplement computer data,we arbitrarily selected two clusters and analyzed their expression levels in A.thaliana ecotypes Col-0and C24 during infection with the yellow strain of Cucumber mosaic virus CMV(Y).Ecotype Col-0 is susceptible to CMV(Y),whereas C24 contains the dominant resistance gene RCY1.Upon infection with CMV(Y),all clustered genes were significantly activated in the resistant ecotype C24.In addition,we demonstrated that posttranslational histone modifications associated with trimethylation of histone H3 lysine 27 are most likely involved in regulation of several cluster genes described in this study.Overall,our experiments indicated that pathogen-response genes in the genome of A.thaliana may be clustered and co-regulated.

  8. Divergent Macroparasite Infections in Parapatric Swiss Lake-Stream Pairs of Threespine Stickleback (Gasterosteus aculeatus.

    Directory of Open Access Journals (Sweden)

    Anssi Karvonen

    Full Text Available Spatial heterogeneity in diversity and intensity of parasitism is a typical feature of most host-parasite interactions, but understanding of the evolutionary implications of such variation is limited. One possible outcome of infection heterogeneities is parasite-mediated divergent selection between host populations, ecotypes or species which may facilitate the process of ecological speciation. However, very few studies have described infections in population-pairs along the speciation continuum from low to moderate or high degree of genetic differentiation that would address the possibility of parasite-mediated divergent selection in the early stages of the speciation process. Here we provide an example of divergent parasitism in freshwater fish ecotypes by examining macroparasite infections in threespine stickleback (Gasterosteus aculeatus of four Swiss lake systems each harbouring parapatric lake-stream ecotype pairs. We demonstrate significant differences in infections within and between the pairs that are driven particularly by the parasite taxa transmitted to fish from benthic invertebrates. The magnitude of the differences tended to correlate positively with the extent of neutral genetic differentiation between the parapatric lake and stream populations of stickleback, whereas no such correlation was found among allopatric populations from similar or contrasting habitats. This suggests that genetic differentiation is unrelated to the magnitude of parasite infection contrasts when gene flow is constrained by geographical barriers while in the absence of physical barriers, genetic differentiation and the magnitude of differences in infections tend to be positively correlated.

  9. Utilization of Genetic Diversity on Establishing Chinese Soybean (G.max) Core Collection

    Institute of Scientific and Technical Information of China (English)

    Qiu Lijuan; Xie Hua; Chang Ruzhen; Li Wei; Wang Wenhui; Zhang Bo; Zhang Minghui; Feng Zhongfu

    2002-01-01

    Genetic diversity plays a veryimportant role in establishing core collation. Inthis study, A total of 405 Chinese soybeanaccessions was selected from the preliminarycore collection, which had 5 different ecotypesfrom three cultivation regions, includingnortheastern spring sowing soybean (NSpSS),huanghuai summer sowing soybean (HSuSS),southern spring sowing soybean (SSpSS),southern summer sowing soybean (SSuSS),southern autumn sowing soybean (SAuSS). Thegenetic diversities and genetic relationship offive ecotypes were analyzed at DNA level byusing SSR markers in order to provideinformation for establishment of Chinesesoybean core collection. A set of 67 SSRprimers were used to analyze these accessions,and detected 502 alleles with averaged 7.49alleles per locus. SAuSS appeared to be thehighest number of alleles, HSuSS had thebiggest genetic diversity indexes and NSpSSwere lowest for both numbers of alleles andgenetic d versity indexes among 5 ecotypes.Since five ecotypes differentiated obviously,various sampling strategy for establishing corecollection should be adapted for differentecotypes based on the number of alleles andgenetic diversity indexes.

  10. Phenotypic plasticity of fine root growth increases plant productivity in pine seedlings

    Directory of Open Access Journals (Sweden)

    Grissom James E

    2004-09-01

    Full Text Available Abstract Background The plastic response of fine roots to a changing environment is suggested to affect the growth and form of a plant. Here we show that the plasticity of fine root growth may increase plant productivity based on an experiment using young seedlings (14-week old of loblolly pine. We use two contrasting pine ecotypes, "mesic" and "xeric", to investigate the adaptive significance of such a plastic response. Results The partitioning of biomass to fine roots is observed to reduce with increased nutrient availability. For the "mesic" ecotype, increased stem biomass as a consequence of more nutrients may be primarily due to reduced fine-root biomass partitioning. For the "xeric" ecotype, the favorable influence of the plasticity of fine root growth on stem growth results from increased allocation of biomass to foliage and decreased allocation to fine roots. An evolutionary genetic analysis indicates that the plasticity of fine root growth is inducible, whereas the plasticity of foliage is constitutive. Conclusions Results promise to enhance a fundamental understanding of evolutionary changes of tree architecture under domestication and to design sound silvicultural and breeding measures for improving plant productivity.

  11. Characterizing and predicting the distribution of Baltic Sea flounder (Platichthys flesus) during the spawning season

    Science.gov (United States)

    Orio, Alessandro; Bergström, Ulf; Casini, Michele; Erlandsson, Mårten; Eschbaum, Redik; Hüssy, Karin; Lehmann, Andreas; Ložys, Linas; Ustups, Didzis; Florin, Ann-Britt

    2017-08-01

    Identification of essential fish habitats (EFH), such as spawning habitats, is important for nature conservation, sustainable fisheries management and marine spatial planning. Two sympatric flounder (Platichthys flesus) ecotypes are present in the Baltic Sea, pelagic and demersal spawning flounder, both displaying ecological and physiological adaptations to the low-salinity environment of this young inland sea. In this study we have addressed three main research questions: 1) What environmental conditions characterize the spatial distribution and abundance of adult flounder during the spawning season? 2) What are the main factors defining the habitats of the two flounder ecotypes during the spawning season? 3) Where are the potential spawning areas of flounder? We modelled catch per unit of effort (CPUE) of flounder from gillnet surveys conducted over the southern and central Baltic Sea in the spring of 2014 and 2015 using generalized additive models. A general model included all the stations fished during the survey while two other models, one for the demersal and one for the pelagic spawning flounder, included only the stations where each flounder ecotype should dominate. The general model captured distinct ecotype-specific signals as it identified dual salinity and water depth responses. The model for the demersal spawning flounder revealed a negative relation with the abundance of round goby (Neogobius melanostomus) and a positive relation with Secchi depth and cod abundance. Vegetation and substrate did not play an important role in the choice of habitat for the demersal ecotype. The model for the pelagic spawning flounder showed a negative relation with temperature and bottom current and a positive relation with salinity. Spatial predictions of potential spawning areas of flounder showed a decrease in habitat availability for the pelagic spawning flounder over the last 20 years in the central part of the Baltic Sea, which may explain part of the observed

  12. Beware batch culture: Seasonality and niche construction predicted to favor bacterial adaptive diversification.

    Science.gov (United States)

    Rocabert, Charles; Knibbe, Carole; Consuegra, Jessika; Schneider, Dominique; Beslon, Guillaume

    2017-03-01

    Metabolic cross-feeding interactions between microbial strains are common in nature, and emerge during evolution experiments in the laboratory, even in homogeneous environments providing a single carbon source. In sympatry, when the environment is well-mixed, the reasons why emerging cross-feeding interactions may sometimes become stable and lead to monophyletic genotypic clusters occupying specific niches, named ecotypes, remain unclear. As an alternative to evolution experiments in the laboratory, we developed Evo2Sim, a multi-scale model of in silico experimental evolution, equipped with the whole tool case of experimental setups, competition assays, phylogenetic analysis, and, most importantly, allowing for evolvable ecological interactions. Digital organisms with an evolvable genome structure encoding an evolvable metabolic network evolved for tens of thousands of generations in environments mimicking the dynamics of real controlled environments, including chemostat or batch culture providing a single limiting resource. We show here that the evolution of stable cross-feeding interactions requires seasonal batch conditions. In this case, adaptive diversification events result in two stably co-existing ecotypes, with one feeding on the primary resource and the other on by-products. We show that the regularity of serial transfers is essential for the maintenance of the polymorphism, as it allows for at least two stable seasons and thus two temporal niches. A first season is externally generated by the transfer into fresh medium, while a second one is internally generated by niche construction as the provided nutrient is replaced by secreted by-products derived from bacterial growth. In chemostat conditions, even if cross-feeding interactions emerge, they are not stable on the long-term because fitter mutants eventually invade the whole population. We also show that the long-term evolution of the two stable ecotypes leads to character displacement, at the level of

  13. Does a shift in host plants trigger speciation in the Alpine leaf beetle Oreina speciosissima (Coleoptera, Chrysomelidae?

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    Borer Matthias

    2011-10-01

    Full Text Available Abstract Background Within the Coleoptera, the largest order in the animal kingdom, the exclusively herbivorous Chrysomelidae are recognized as one of the most species rich beetle families. The evolutionary processes that have fueled radiation into the more than thirty-five thousand currently recognized leaf beetle species remain partly unresolved. The prominent role of leaf beetles in the insect world, their omnipresence across all terrestrial biomes and their economic importance as common agricultural pest organisms make this family particularly interesting for studying the mechanisms that drive diversification. Here we specifically focus on two ecotypes of the alpine leaf beetle Oreina speciosissima (Scop., which have been shown to exhibit morphological differences in male genitalia roughly corresponding to the subspecies Oreina speciosissima sensu stricto and Oreina speciosissima troglodytes. In general the two ecotypes segregate along an elevation gradient and by host plants: Oreina speciosissima sensu stricto colonizes high forb vegetation at low altitude and Oreina speciosissima troglodytes is found in stone run vegetation at higher elevations. Both host plants and leaf beetles have a patchy geographical distribution. Through use of gene sequencing and genome fingerprinting (AFLP we analyzed the genetic structure and habitat use of Oreina speciosissima populations from the Swiss Alps to examine whether the two ecotypes have a genetic basis. By investigating a wide range of altitudes and focusing on the structuring effect of habitat types, we aim to provide answers regarding the factors that drive adaptive radiation in this phytophagous leaf beetle. Results While little phylogenetic resolution was observed based on the sequencing of four DNA regions, the topology and clustering resulting from AFLP genotyping grouped specimens according to their habitat, mostly defined by plant associations. A few specimens with intermediate morphologies

  14. Ecophysiological traits sustaining tree growth and survival under drying climate in the Mediterranean

    Science.gov (United States)

    Yakir, D.; Klein, T.; Cohen, S.

    2011-12-01

    The rate of evolutionary adaptation in long-lived organisms such as forest trees cannot compete with the current and predicted rate of climate change. Tree growth and survival under warming and drying climate, such as predicted for the Mediterranean and other regions, will depend therefore on the existing plasticity of physiological and phenological traits. We examined seven physiological and phenological parameters in Pinus halepensis, a drought resistant Mediterranean tree species, using five ecotypes growing under meso-Mediterranean (MM), thermo-Mediterranean (TM), and semi-arid (SA) climates. The results revealed that both phenotypic plasticity and locally adapted ecotypes contributed, differentially, to the success of this species across a wide range of climatic conditions. While some ecotypes had an inherent xylem resistance to embolism (percent loss of conductivity traits to compensate for lower compatibility with the drying and warming climate in other traits allowed sustained growth in all ecotypes. Published data on the survival of these ecotypes under harsher conditions than used here indicated that ultimately xylem resistance to embolism was a key to survival. Addressing specifically the issue of tree hydraulic conductance system in greenhouse and field studies indicated that although P. halepensis performs well under drought conditions it has a sensitive hydraulic system. This was reflected in 50% loss of hydraulic conductivity at relatively high leaf water potential of -3.1 MPa. This, however, was compensated for by a narrow safety margin allowing leaf gas exchange up to leaf water potential of -2.8 MPa. The hydraulic sensitivity also requires fast cavitation reversal, which was indeed observed in the dry season on hourly time-scale: Two cycles of cavitation and reversal observed during morning and afternoon, which were also reflected in a decoupling between sap flow and leaf transpiration. The results indicate newly observed hydraulic capabilities of

  15. EST and EST-SSR marker resources for Iris

    Directory of Open Access Journals (Sweden)

    Taylor Christopher A

    2009-06-01

    Full Text Available Abstract Background Limited DNA sequence and DNA marker resources have been developed for Iris (Iridaceae, a monocot genus of 200–300 species in the Asparagales, several of which are horticulturally important. We mined an I. brevicaulis-I. fulva EST database for simple sequence repeats (SSRs and developed ortholog-specific EST-SSR markers for genetic mapping and other genotyping applications in Iris. Here, we describe the abundance and other characteristics of SSRs identified in the transcript assembly (EST database and the cross-species utility and polymorphisms of I. brevicaulis-I. fulva EST-SSR markers among wild collected ecotypes and horticulturally important cultivars. Results Collectively, 6,530 ESTs were produced from normalized leaf and root cDNA libraries of I. brevicaulis (IB72 and I. fulva (IF174, and assembled into 4,917 unigenes (1,066 contigs and 3,851 singletons. We identified 1,447 SSRs in 1,162 unigenes and developed 526 EST-SSR markers, each tracing a different unigene. Three-fourths of the EST-SSR markers (399/526 amplified alleles from IB72 and IF174 and 84% (335/399 were polymorphic between IB25 and IF174, the parents of I. brevicaulis × I. fulva mapping populations. Forty EST-SSR markers were screened for polymorphisms among 39 ecotypes or cultivars of seven species – 100% amplified alleles from wild collected ecotypes of Louisiana Iris (I.brevicaulis, I.fulva, I. nelsonii, and I. hexagona, whereas 42–52% amplified alleles from cultivars of three horticulturally important species (I. pseudacorus, I. germanica, and I. sibirica. Ecotypes and cultivars were genetically diverse – the number of alleles/locus ranged from two to 18 and mean heterozygosity was 0.76. Conclusion Nearly 400 ortholog-specific EST-SSR markers were developed for comparative genetic mapping and other genotyping applications in Iris, were highly polymorphic among ecotypes and cultivars, and have broad utility for genotyping applications within

  16. ESTUDIO DE LA DIVERSIDAD CITOGENÉTICA DE Physalis peruviana L. (Solanaceae Study of the cytogenetic diversity of Physalis peruviana L. (Solanaceae

    Directory of Open Access Journals (Sweden)

    C NOHRA

    2006-06-01

    Full Text Available Se caracterizó el cariotipo de cinco ecotipos de Physalis peruviana L., tres silvestres distribuidas en los municipios de Villa de Leyva (Boyacá, Colombia, La Calera y Choachí (Cundinamarca, Colombia y dos cultivados, uno de ellos nativo, el ecotipo Colombia distribuido en el municipio de Subachoque (Cundinamarca y uno foráneo, procedente de Kenia, cultivado en el municipio de Paipa (Cundinamarca. Ápices radicales obtenidos a partir de semillas y de hojas en medios de cultivo in vitro enriquecidos con auxinas se emplearon para estandarizar el protocolo de obtención de cromosomas, con las diferentes técnicas de pretratamiento, fijación, hidrólisis y montaje de las muestras. Adicionalmente se evaluó la duración del ciclo celular para establecer la hora mitótica. Se encontró variabilidad genética entre los ecotipos evaluados. Los ecotipos silvestres presentaron una dotación cromosómica 2n=24, el ecotipo Colombia 2n=32 y el ecotipo Kenia 2n=48. Los ecotipos exhibieron también variación en las características morfológicas y anatómicas, que de acuerdo a la literatura, son un reflejo del nivel de ploidía, como altura, área foliar, número de estomas/mm², número de cloroplastos en las células guarda de los estomas, diámetro de frutos, semillas y contenido de masa seca.We report here the karyotype characterization of five Physalis peruviana L. ecotypes. Three wild types were collected from the areas around Villa de Leyva (Boyacá, Colombia, La Calera and Choachí municipalities (Cundinamarca, Colombia and two were from cultivated cape gooseberry crops. One of the latter was the native Colombia ecotype found near the Subachoque municipality (Cundinamarca and the other was a foreign ecotype from Kenya, which had been cultivated near Paipa municipality (Cundinamarca. Karyotypes were obtained after standardizing a protocol involving obtation of radical apexes from seeds and leaves, using in vitro auxinenriched culture medium. The

  17. Caryopsis Dormancy Patterns of Wild Barley(Hordeum spontaneum)and Its Association with Agronomic Traits and Ecogeographical Parameters%野生二棱大麦种子休眠型态与农艺性状及生态地理因素相关性研究

    Institute of Scientific and Technical Information of China (English)

    严俊; 王莹; NEVO Eviatar; GUTTERMAN Yitzchak; 程剑平

    2011-01-01

    对来自以色列不同地区16个生态型野生二棱大麦种子的休眠型态与其农艺性状及起源地生态地里因素的相关性进行了研究.结果表明:高温(40℃)储藏可以打破种子的休眠;16个生态型种子在高温处理下的萌发率表现出显著差异,其休眠打破过程显示出不同型态的对数生长曲线:8个旱生生态型为S型,而8个湿生生态型为倒L型.休眠深度用实际达到最大萌发率的时间度量,最低休眠深度(15.6 d)是来自湿润地区"进化峡谷"的生态型 37-N,而最深休眠深度(103.1 d)是来自干旱地区Ein-Zukim(死海附近)的生态型32-6.此外,对11个物候及农艺性状指标与休眠深度做斯皮尔曼秩相关分析,结果有9个显示出显著相关,尤其是粒重与休眠深度有极显著相关性.同时,休眠深度与起源地15个生态地理因素中的9个有显著相关,种子休眠主要受其起源地的地理位置、温度和水分条件等影响.可见,野生二棱大麦自然选择进化了休眠特性去应对干热环境而繁衍生息.本研究结果可用于进一步遗传研究和现代栽培大麦品种的改良.%Patterns in caryopsis dormancy and its agronomic and ecogeographical associations were investigated in 16 wild barley (Hordeum spontaneum) ecotypes from different habitats in Israel.The results showed that heat treatment (40℃) could break dormancy of caryopses.Germination percentages under breaking dormancy treatments were significantly different among the 16 ecotypes.Dormancy-break patterns were fitted by logistic growth curves: all eight xeric ecotypes showed an S-shaped curve,whereas all eight mesic ecotypes displayed a reverse L-shaped curve.For depth of dormancy,as reflected by the time to maximum germination percentage,the lowest (15.6 days) was for the ecotype 37-N from the north slop of Evolution Canyon (mesic),whereas it was the highest (103.1 days) for 32-6 from Ein-Zukim (near Dead Sea) (xeric).In addition,nine of 11

  18. Exploring Potential U.S. Switchgrass Production for Lignocellulosic Ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Gunderson, Carla A [ORNL; Davis, Ethan [ORNL; Jager, Yetta [ORNL; West, Tristram O. [ORNL; Perlack, Robert D [ORNL; Brandt, Craig C [ORNL; Wullschleger, Stan D [ORNL; Baskaran, Latha Malar [ORNL; Webb, Erin [ORNL; Downing, Mark [ORNL

    2008-08-01

    In response to concerns about oil dependency and the contributions of fossil fuel use to climatic change, the U.S. Department of Energy has begun a research initiative to make 20% of motor fuels biofuel based in 10 years, and make 30% of fuels bio-based by 2030. Fundamental to this objective is developing an understanding of feedstock dynamics of crops suitable for cellulosic ethanol production. This report focuses on switchgrass, reviewing the existing literature from field trials across the United States, and compiling it for the first time into a single database. Data available from the literature included cultivar and crop management information, and location of the field trial. For each location we determined latitude and longitude, and used this information to add temperature and precipitation records from the nearest weather station. Within this broad database we were able to identify the major sources of variation in biomass yield, and to characterize yield as a function of some of the more influential factors, e.g., stand age, ecotype, precipitation and temperature in the year of harvest, site latitude, and fertilization regime. We then used a modeling approach, based chiefly on climatic factors and ecotype, to predict potential yields for a given temperature and weather pattern (based on 95th percentile response curves), assuming the choice of optimal cultivars and harvest schedules. For upland ecotype varieties, potential yields were as high as 18 to 20 Mg/ha, given ideal growing conditions, whereas yields in lowland ecotype varieties could reach 23 to 27 Mg/ha. The predictive equations were used to produce maps of potential yield across the continental United States, based on precipitation and temperature in the long term climate record, using the Parameter-elevation Regressions on Independent Slopes Model (PRISM) in a Geographic Information System (GIS). Potential yields calculated via this characterization were subsequently compared to the Oak Ridge

  19. Transcriptome analysis deciphers evolutionary mechanisms underlying genetic differentiation between coastal and offshore anchovy populations in the Bay of Biscay

    KAUST Repository

    Montes, Iratxe

    2016-09-13

    Morphometry and otolith microchemistry point to the existence of two populations of the European anchovy (Engraulis encrasicolus) in the Bay of Biscay: one in open seawaters, and a yet unidentified population in coastal waters. To test this hypothesis, we assembled a large number of samples from the region, including 587 juveniles and spawning adults from offshore and coastal waters, and 264 fish from other locations covering most of the species’ European range. These samples were genotyped for 456 exonic SNPs that provide a robust way to decipher adaptive processes in these populations. Two genetically differentiated populations of anchovy inhabit the Bay of Biscay with different population dynamics: (1) a large offshore population associated with marine waters included in the wide-shelf group, and (2) a coastal metapopulation adapted to estuarine environments in the Bay of Biscay and North Sea included in the narrow-shelf group. Transcriptome analysis identified neutral and adaptive evolutionary processes underlying differentiation between these populations. Reduced gene flow between offshore and coastal populations in the Bay of Biscay appears to result from divergence between two previously isolated gene pools adapted to contrasting habitats and now in secondary contact. Eleven molecular markers appear to mark divergent selection between the ecotypes, and a majority of these markers are associated with salinity variability. Ecotype differences at two outlier genes, TSSK6 and basigin, may hinder gamete compatibility between the ecotypes and reinforce reproductive isolation. Additionally, possible convergent evolution between offshore and coastal populations in the Bay of Biscay has been detected for the syntaxin1B-otoferlin gene system, which is involved in the control of larval buoyancy. Further study of exonic markers opens the possibility of understanding the mechanisms of adaptive divergence between European anchovy populations. © 2016, Springer

  20. Floral Biology and Hybridization Potential of Nine Accessions of Physic Nut Jatropha curcas L. originating from Three Continents

    Directory of Open Access Journals (Sweden)

    Ahoton, LE.

    2012-01-01

    Full Text Available Jatropha curcas is a shrub which has an important economic and medicinal role in tropical and subtropical zones of the world. The oil of its kernels can serve as fuel feedstock to produce diesel, indicating its potential as a renewable source of energy. In an attempt to introduce new variation into cultivated Jatropha curcas, a program of intraspecific hybridization with several ecotypes originating from Africa, Asia and America was undertaken. Field studies were performed over three years 2009, 2010 and 2011. Before achieving hybridization, the floral ratio and the breeding system of physic nut were studied in Southern Benin ecological conditions. Significant differences (P< 0.05 were observed between the analysed ecotypes regarding the number of female flowers. This study has also confirmed that the breeding system of Jatropha curcas is essentially outcrossing and that foraging insects are the main pollination actors of female flowers. New intraspecific hybrid combinations were produced involving nine accessions. Crosses results varied according to the origin and the direction of the hybridization. Crosses between accessions of J. curcas originating from Africa and Asia gave hybrids without difficulty. The data obtained confirm that apomixis might play a major role in J. curcas a reproductive biology. Considering the high number of female flowers per inflorescence produced by the accession from Ecuador, and the large genetic distance existing between this accession and those from Africa and Asia, it should constitute a valuable genetic stock for the development of F1 hybrids with local ecotypes of J. curcas. However, the use of growth regulators might be necessary to improve the hybridization success rate when it is used as female parent.

  1. Determining the most effective traits to improve saffron (Crocus sativus L.) yield.

    Science.gov (United States)

    Bayat, Mahdi; Rahimi, Mehdi; Ramezani, Mehdi

    2016-01-01

    To determine the effective traits to improve saffron yield, a split plot design based on RBCD was done in Mashhad region in Iran for three years (2012-2014). The results showed that all traits except number of daughter corm, fresh weight of daughter corm and dry leaf weight had low general heritability. Results of genotypic and phenotypic coefficients of variation and genetic advance demonstrated that the majority of traits had a low diversity and the selection did not have any effect in improving the traits. As a result, the best way to increase saffron yield is improvement of farm management. It was also found that saffron yield had the highest phenotypic and genotypic correlations with fresh and dry weight of daughter corm and dry and fresh flower weight. Therefore, the efforts to improve these traits will increase saffron yield. According to the present study 5-Jun to 5-Jul was found to be the best sowing date for planting saffron. Also, the Mashhad and Torbat ecotypes were the best ecotypes in this study. Phenotypic and genotypic path analysis showed that in the first step three traits number of daughter corm, fresh flower weight and flower number and in the second step traits fresh weight of daughter corm, dry flower weight and dry leaf weight interred to the regression model and had the highest positive direct and indirect effects on saffron yield. Mainly, it can be derived that the implementation of correct farm management including appropriate sowing date, saffron ecotypes, proper density, bigger and higher quality saffron corm can play an important role in improving yield components and subsequently increasing saffron yield.

  2. Anaplasma phagocytophilum in sheep and goats in central and southeastern China.

    Science.gov (United States)

    Yang, Jifei; Liu, Zhijie; Niu, Qingli; Liu, Junlong; Han, Rong; Guan, Guiquan; Li, Youquan; Liu, Guangyuan; Luo, Jianxun; Yin, Hong

    2016-11-21

    Anaplasma phagocytophilum is wide spread throughout the world and impacts both human and animal health. Several distinct ecological clusters and ecotypes of the agent have been established on the basis of various genetic loci. However, information on the genetic variability of A. phagocytophilum isolates in China represents a gap in knowledge. The objective of this study was to determine the prevalence and genetic characterization of A. phagocytophilum in small ruminants in central and southeastern China. The presence of A. phagocytophilum was determined in 421 blood samples collected from small ruminants by PCR. Positive samples were genetically characterized based on 16S rRNA and groEL genes. Statistical analyses were conducted to identify ecotypes of A. phagocytophilum strains, to assess their host range and zoonotic potential. Out of 421 sampled small ruminants, 106 (25.2%) were positive for A. phagocytophilum. The positive rate was higher in sheep (35.1%, 40/114) than in goats (26.4%, 66/307) (P Anaplasma sp. was identified and closely related to an isolate previously reported in Hyalomma asiaticum, which clustered independently from all recognized Anaplasma species. A molecular survey of A. phagocytophilum was conducted in sheep and goats from ten provinces in central and southeastern China. Two 16S rRNA variants and a new ecotype of A. phagocytophilum were identified in small ruminants in China. Moreover, a potential novel Anaplasma species was reported in goats. Our findings provide additional information on the complexity of A. phagocytophilum in terms of genetic diversity in China.

  3. Sequence based polymorphic (SBP marker technology for targeted genomic regions: its application in generating a molecular map of the Arabidopsis thaliana genome

    Directory of Open Access Journals (Sweden)

    Sahu Binod B

    2012-01-01

    Full Text Available Abstract Background Molecular markers facilitate both genotype identification, essential for modern animal and plant breeding, and the isolation of genes based on their map positions. Advancements in sequencing technology have made possible the identification of single nucleotide polymorphisms (SNPs for any genomic regions. Here a sequence based polymorphic (SBP marker technology for generating molecular markers for targeted genomic regions in Arabidopsis is described. Results A ~3X genome coverage sequence of the Arabidopsis thaliana ecotype, Niederzenz (Nd-0 was obtained by applying Illumina's sequencing by synthesis (Solexa technology. Comparison of the Nd-0 genome sequence with the assembled Columbia-0 (Col-0 genome sequence identified putative single nucleotide polymorphisms (SNPs throughout the entire genome. Multiple 75 base pair Nd-0 sequence reads containing SNPs and originating from individual genomic DNA molecules were the basis for developing co-dominant SBP markers. SNPs containing Col-0 sequences, supported by transcript sequences or sequences from multiple BAC clones, were compared to the respective Nd-0 sequences to identify possible restriction endonuclease enzyme site variations. Small amplicons, PCR amplified from both ecotypes, were digested with suitable restriction enzymes and resolved on a gel to reveal the sequence based polymorphisms. By applying this technology, 21 SBP markers for the marker poor regions of the Arabidopsis map representing polymorphisms between Col-0 and Nd-0 ecotypes were generated. Conclusions The SBP marker technology described here allowed the development of molecular markers for targeted genomic regions of Arabidopsis. It should facilitate isolation of co-dominant molecular markers for targeted genomic regions of any animal or plant species, whose genomic sequences have been assembled. This technology will particularly facilitate the development of high density molecular marker maps, essential for

  4. Red maca (Lepidium meyenii reduced prostate size in rats

    Directory of Open Access Journals (Sweden)

    Rubio Julio

    2005-01-01

    Full Text Available Abstract Background Epidemiological studies have found that consumption of cruciferous vegetables is associated with a reduced risk of prostate cancer. This effect seems to be due to aromatic glucosinolate content. Glucosinolates are known for have both antiproliferative and proapoptotic actions. Maca is a cruciferous cultivated in the highlands of Peru. The absolute content of glucosinolates in Maca hypocotyls is relatively higher than that reported in other cruciferous crops. Therefore, Maca may have proapoptotic and anti-proliferative effects in the prostate. Methods Male rats treated with or without aqueous extracts of three ecotypes of Maca (Yellow, Black and Red were analyzed to determine the effect on ventral prostate weight, epithelial height and duct luminal area. Effects on serum testosterone (T and estradiol (E2 levels were also assessed. Besides, the effect of Red Maca on prostate was analyzed in rats treated with testosterone enanthate (TE. Results Red Maca but neither Yellow nor Black Maca reduced significantly ventral prostate size in rats. Serum T or E2 levels were not affected by any of the ecotypes of Maca assessed. Red Maca also prevented the prostate weight increase induced by TE treatment. Red Maca administered for 42 days reduced ventral prostatic epithelial height. TE increased ventral prostatic epithelial height and duct luminal area. These increases by TE were reduced after treatment with Red Maca for 42 days. Histology pictures in rats treated with Red Maca plus TE were similar to controls. Phytochemical screening showed that aqueous extract of Red Maca has alkaloids, steroids, tannins, saponins, and cardiotonic glycosides. The IR spectra of the three ecotypes of Maca in 3800-650 cm (-1 region had 7 peaks representing 7 functional chemical groups. Highest peak values were observed for Red Maca, intermediate values for Yellow Maca and low values for Black Maca. These functional groups correspond among others to benzyl

  5. The Arabidopsis Epithiospecifier Protein Promotes the Hydrolysis of Glucosinolates to Nitriles and Influences Trichoplusia ni Herbivory

    Science.gov (United States)

    Lambrix, Virginia; Reichelt, Michael; Mitchell-Olds, Thomas; Kliebenstein, Daniel J.; Gershenzon, Jonathan

    2001-01-01

    Glucosinolates are anionic thioglucosides that have become one of the most frequently studied groups of defensive metabolites in plants. When tissue damage occurs, the thioglucoside linkage is hydrolyzed by enzymes known as myrosinases, resulting in the formation of a variety of products that are active against herbivores and pathogens. In an effort to learn more about the molecular genetic and biochemical regulation of glucosinolate hydrolysis product formation, we analyzed leaf samples of 122 Arabidopsis ecotypes. A distinct polymorphism was observed with all ecotypes producing primarily isothiocyanates or primarily nitriles. The ecotypes Columbia (Col) and Landsberg erecta (Ler) differed in their hydrolysis products; therefore, the Col × Ler recombinant inbred lines were used for mapping the genes controlling this polymorphism. The major quantitative trait locus (QTL) affecting nitrile versus isothiocyanate formation was found very close to a gene encoding a homolog of a Brassica napus epithiospecifier protein (ESP), which causes the formation of epithionitriles instead of isothiocyanates during glucosinolate hydrolysis in the seeds of certain Brassicaceae. The heterologously expressed Arabidopsis ESP was able to convert glucosinolates both to epithionitriles and to simple nitriles in the presence of myrosinase, and thus it was more versatile than previously described ESPs. The role of ESP in plant defense is uncertain, because the generalist herbivore Trichoplusia ni (the cabbage looper) was found to feed more readily on nitrile-producing than on isothiocyanate-producing Arabidopsis. However, isothiocyanates are frequently used as recognition cues by specialist herbivores, and so the formation of nitriles instead of isothiocyanates may allow Arabidopsis to be less apparent to specialists. PMID:11752388

  6. Efecto del estrés por sequía en el desarrollo de la antracnosis en tres ecotipos de Stylosanthes spp.

    Directory of Open Access Journals (Sweden)

    Nuñez Luis E.

    1986-09-01

    Full Text Available En condiciones de invernadero, se evaluó el efecto del estrés por segura sobre la incidencia y severidad de antracnosis, causada por C. gloesporioides en S. guianensis var. guianensis CIAT 136, var pauciflora CIAT 1283 y S. capitata CIAT 1315; al mismo tiempo se estudió las diferentes respuestas morfológicas y fisiológicas de los tres ecotipos bajo déficit de agua en el suelo y presión del patógeno. Los ecotipos de Stylosanthes estudiados no solo toleran la deshidratación (- 26 bares sino también exhiben importantes mecanismos de adaptación morfológica que tienden a evitarla. EI efecto aditivo del estrés causado por antracnosis en condiciones de sequía, afectó la persistencia de los ecotipos de Stylosanthes spp. más susceptibles.

    Under glasshouse conditiones, the effect of drought stress on the incidence and severity of antracnosis, caused by C. gloeosporioides, in S. guianensis var. guianensis CIAT 136, var. pauciflora CIAT 1283 and in S. capitata CIAT 1315 was evaluated; at the same time, the different morphological and physiological response of the three ecotypes under deficiency of water in the soil and pathogen pressure were studied. The ecotypes of Stylosanthes studies not only tolerate dehydration (- 26 bares but also shoved important mechanisms of morphological adaptation that they have to avoid it. The additive effect of stress caused by antracnose in drought conditions affected the persistence of more susceptible ecotypes.

  7. Genetic subdivision and candidate genes under selection in North American grey wolves.

    Science.gov (United States)

    Schweizer, Rena M; vonHoldt, Bridgett M; Harrigan, Ryan; Knowles, James C; Musiani, Marco; Coltman, David; Novembre, John; Wayne, Robert K

    2016-01-01

    Previous genetic studies of the highly mobile grey wolf (Canis lupus) found population structure that coincides with habitat and phenotype differences. We hypothesized that these ecologically distinct populations (ecotypes) should exhibit signatures of selection in genes related to morphology, coat colour and metabolism. To test these predictions, we quantified population structure related to habitat using a genotyping array to assess variation in 42 036 single-nucleotide polymorphisms (SNPs) in 111 North American grey wolves. Using these SNP data and individual-level measurements of 12 environmental variables, we identified six ecotypes: West Forest, Boreal Forest, Arctic, High Arctic, British Columbia and Atlantic Forest. Next, we explored signals of selection across these wolf ecotypes through the use of three complementary methods to detect selection: FST /haplotype homozygosity bivariate percentilae, bayescan, and environmentally correlated directional selection with bayenv. Across all methods, we found consistent signals of selection on genes related to morphology, coat coloration, metabolism, as predicted, as well as vision and hearing. In several high-ranking candidate genes, including LEPR, TYR and SLC14A2, we found variation in allele frequencies that follow environmental changes in temperature and precipitation, a result that is consistent with local adaptation rather than genetic drift. Our findings show that local adaptation can occur despite gene flow in a highly mobile species and can be detected through a moderately dense genomic scan. These patterns of local adaptation revealed by SNP genotyping likely reflect high fidelity to natal habitats of dispersing wolves, strong ecological divergence among habitats, and moderate levels of linkage in the wolf genome. © 2015 John Wiley & Sons Ltd.

  8. Evolution of senescence in nature: physiological evolution in populations of garter snake with divergent life histories.

    Science.gov (United States)

    Robert, Kylie A; Bronikowski, Anne M

    2010-02-01

    Evolutionary theories of aging are linked to life-history theory in that age-specific schedules of reproduction and survival determine the trajectory of age-specific mutation/selection balances across the life span and thus the rate of senescence. This is predicted to manifest at the organismal level in the evolution of energy allocation strategies of investing in somatic maintenance and robust stress responses in less hazardous environments in exchange for energy spent on growth and reproduction. Here we report experiments from long-studied populations of western terrestrial garter snakes (Thamnophis elegans) that reside in low and high extrinsic mortality environments, with evolved long and short life spans, respectively. Laboratory common-environment colonies of these two ecotypes were tested for a suite of physiological traits after control and stressed gestations. In offspring derived from control and corticosterone-treated dams, we measured resting metabolism; mitochondrial oxygen consumption, ATP and free radical production rates; and erythrocyte DNA damage and repair ability. We evaluated whether these aging biomarkers mirrored the evolution of life span and whether they were sensitive to stress. Neonates from the long-lived ecotype (1) were smaller, (2) consumed equal amounts of oxygen when corrected for body mass, (3) had DNA that damaged more readily but repaired more efficiently, and (4) had more efficient mitochondria and more efficient cellular antioxidant defenses than short-lived snakes. Many ecotype differences were enhanced in offspring derived from stress-treated dams, which supports the conclusion that nongenetic maternal effects may further impact the cellular stress defenses of offspring. Our findings reveal that physiological evolution underpins reptilian life histories and sheds light on the connectedness between stress response and aging pathways in wild-dwelling organisms.

  9. Plant winners and losers during grassland N-eutrophication differ in biomass allocation and mycorrhizas.

    Science.gov (United States)

    Johnson, Nancy Collins; Rowland, Diane L; Corkidi, Lea; Allen, Edith B

    2008-10-01

    Human activities release tremendous amounts of nitrogenous compounds into the atmosphere. Wet and dry deposition distributes this airborne nitrogen (N) on otherwise pristine ecosystems. This eutrophication process significantly alters the species composition of native grasslands; generally a few nitrophilic plant species become dominant while many other species disappear. The functional equilibrium model predicts that, compared to species that decline in response to N enrichment, nitrophilic grass species should respond to N enrichment with greater biomass allocation aboveground and reduced allocation to roots and mycorrhizas. The mycorrhizal feedback hypothesis states that the composition of mycorrhizal fungal communities may influence the composition of plant communities, and it predicts that N enrichment may generate reciprocal shifts in the species composition of mycorrhizal fungi and plants. We tested these hypotheses with experiments that compared biomass allocation and mycorrhizal function of four grass ecotypes (three species), two that gained and two that lost biomass and cover in response to long-term N enrichment experiments at Cedar Creek and Konza Long-Term Ecological Research grasslands. Local grass ecotypes were grown in soil from their respective sites and inoculated with whole-soil inoculum collected from either fertilized (FERT) or unfertilized (UNFERT) plots. Our results strongly support the functional equilibrium model. In both grassland systems the nitrophilic grass species grew taller, allocated more biomass to shoots than to roots, and formed fewer mycorrhizas compared to the grass species that it replaced. Our results did not fully support the hypothesis that N-induced changes in the mycorrhizal fungal community were drivers of the plant community shifts that accompany N eutrophication. The FERT and UNFERT soil inoculum influenced the growth of the grasses differently, but this varied with site and grass ecotype in both expected and

  10. Physico-Chemical Characterization Of Maluku Nutmeg Oil

    Directory of Open Access Journals (Sweden)

    Ilyas Marzuki

    2014-05-01

    Full Text Available The essential oil of Banda nutmeg was extracted using hydro-distillation method to characterize their essential oil and volatile components.  Banda, Ambon, and Luhu nutmegs were chosen as sample ecotypes. Nutmeg oils were subjected to physico-chemical and GC-MC analyses.  Results indicated that nutmeg from the three ecotypes produced uncolored oils with the contents in mature seed were 11.69, 11.92, and 9.99%, respectively. Meanwhile those of immature seeds contained 13.32, 11.99, and 11.03% respectively.  Furthermore, the physico-chemical of the oil are specific gravity 0.897 to 0.909 g/ml; refraction index, 1.489 to 1.491; and optical rotation, +11.40 to +16,30.GC-MS analysis suggested that essential oils Maluku nutmegs composed of 28 to 31 components and also showed that nutmeg from Banda comprised 52.8% monoterpene hydrocarbon (MH, 21.11% oxygenated monoterpene (OM, and 18,04% aromatic compound (AC; Ambon’s 45.12% MH, 24.51% OM, and 16.97% AC; and Luhu’s 56.06% MH, 27.34% OM, and 13.62% AC.  Further analysis indicated that there were four important volatile oils fractions in nutmegs i.e. myristicin, elemicin, safrole, and eugenol. Maluku nutmeg contain 5.57 to 13.76% myristicin and 0.97 to 2.46% safrole. In conclusion, nutmeg oil shows a high stability in all physico-chemical properties.  Nutmeg from Banda ecotype has the highest content in myristicin.

  11. Effect of different levels of nitrogen deficiency on switchgrass seedling growth

    Institute of Scientific and Technical Information of China (English)

    Yi; Zhu; Xifeng; Fan; Xincun; Hou; Juying; Wu; Tao; Wang

    2014-01-01

    Switchgrass(Panicum virgatum L.) is a warm-season rhizomatous perennial grass that can tolerate diverse abiotic stresses while yielding relatively high biomass, and is considered a leading biofuel feedstock for marginal lands. Nitrogen(N) is crucial for the growth and development of switchgrass, and its tolerance to low N supply and high N use efficiency are very important for its production under poor conditions. The large-scale planting of switchgrass on marginal lands could be an effective approach to solving the problem of feedstock supply for biomass energy. This study used a hydroponic experiment to evaluate the effect of N deficiency on switchgrass seedlings. Three N treatments(0, 0.15, and 1.50 mmol L-1Hoagland’s solution)and six cultivars were used, three of each ecotype(upland and lowland). The results showed that biomass, leaf area, root surface area, net photosynthesis, and total chlorophyll content significantly decreased under low N treatments compared with those in full strength Hoagland’s nutrient solution. However, once established, all plants survived extreme N stress(0 mmol L-1) and, to some extent, were productive. Cultivar Kanlow performed best of the six cultivars under stress. Significant interactions between stress treatment and cultivars showed that breeding for cultivars with high yield and superior performance under N deficiency is warranted. The lowland outperformed the upland ecotypes under stress, suggesting that lowland cultivars may survive and be productive under a wider range of stress conditions.However, given the better adaptability of lowland ecotypes to hydroponic cultivation, further study is needed.

  12. Small RNA-directed epigenetic natural variation in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Jixian Zhai

    2008-04-01

    Full Text Available Progress in epigenetics has revealed mechanisms that can heritably regulate gene function independent of genetic alterations. Nevertheless, little is known about the role of epigenetics in evolution. This is due in part to scant data on epigenetic variation among natural populations. In plants, small interfering RNA (siRNA is involved in both the initiation and maintenance of gene silencing by directing DNA methylation and/or histone methylation. Here, we report that, in the model plant Arabidopsis thaliana, a cluster of approximately 24 nt siRNAs found at high levels in the ecotype Landsberg erecta (Ler could direct DNA methylation and heterochromatinization at a hAT element adjacent to the promoter of FLOWERING LOCUS C (FLC, a major repressor of flowering, whereas the same hAT element in ecotype Columbia (Col with almost identical DNA sequence, generates a set of low abundance siRNAs that do not direct these activities. We have called this hAT element MPF for Methylated region near Promoter of FLC, although de novo methylation triggered by an inverted repeat transgene at this region in Col does not alter its FLC expression. DNA methylation of the Ler allele MPF is dependent on genes in known silencing pathways, and such methylation is transmissible to Col by genetic crosses, although with varying degrees of penetrance. A genome-wide comparison of Ler and Col small RNAs identified at least 68 loci matched by a significant level of approximately 24 nt siRNAs present specifically in Ler but not Col, where nearly half of the loci are related to repeat or TE sequences. Methylation analysis revealed that 88% of the examined loci (37 out of 42 were specifically methylated in Ler but not Col, suggesting that small RNA can direct epigenetic differences between two closely related Arabidopsis ecotypes.

  13. Do the same genes underlie parallel phenotypic divergence in different Littorina saxatilis populations?

    Science.gov (United States)

    Westram, A M; Galindo, J; Alm Rosenblad, M; Grahame, J W; Panova, M; Butlin, R K

    2014-09-01

    Parallel patterns of adaptive divergence and speciation are cited as powerful evidence for the role of selection driving these processes. However, it is often not clear whether parallel phenotypic divergence is underlain by parallel genetic changes. Here, we asked about the genetic basis of parallel divergence in the marine snail Littorina saxatilis, which has repeatedly evolved coexisting ecotypes adapted to either crab predation or wave action. We sequenced the transcriptome of snails of both ecotypes from three distant geographical locations (Spain, Sweden and United Kingdom) and mapped the reads to the L. saxatilis reference genome. We identified genomic regions potentially under divergent selection between ecotypes within each country, using an outlier approach based on F(ST) values calculated per locus. In line with previous studies indicating that gene reuse is generally common, we expected to find extensive sharing of outlier loci due to recent shared ancestry and gene flow between at least two of the locations in our study system. Contrary to our expectations, we found that most outliers were country specific, suggesting that much of the genetic basis of divergence is not shared among locations. However, we did find that more outliers were shared than expected by chance and that differentiation of shared outliers is often generated by the same SNPs. We discuss two mechanisms potentially explaining the limited amount of sharing we observed. First, a polygenic basis of divergent traits might allow for multiple distinct molecular mechanisms generating the same phenotypic patterns. Second, additional, location-specific axes of selection that we did not focus on in this study may produce distinct patterns of genetic divergence within each site.

  14. Recombination does not hinder formation or detection of ecological species of Synechococcus inhabiting a hot spring cyanobacterial mat

    Directory of Open Access Journals (Sweden)

    Melanie Crystal Melendrez

    2016-01-01

    Full Text Available Recent studies of bacterial speciation have claimed to support the biological species concept—that reduced recombination is required for bacterial populations to diverge into species. This conclusion has been reached from the discovery that ecologically distinct clades show lower rates of recombination than that which occurs among closest relatives. However, these previous studies did not attempt to determine whether the more-rapidly recombining close relatives within the clades studied may also have diversified ecologically, without benefit of sexual isolation. Here we have measured the impact of recombination on ecological diversification within and between two ecologically distinct clades (A and B´ of Synechococcus in a hot spring microbial mat in Yellowstone National Park, using a cultivation-free, multi-locus approach. Bacterial artificial chromosome (BAC libraries were constructed from mat samples collected at 60°C and 65°C. Analysis of multiple linked loci near Synechococcus 16S rRNA genes showed little evidence of recombination between the A and B´ lineages, but a record of recombination was apparent within each lineage. Recombination and mutation rates within each lineage were of similar magnitude, but recombination had a somewhat greater impact on sequence diversity than mutation, as also seen in many other bacteria and archaea. Despite recombination within the A and B´ lineages, there was evidence of ecological diversification within each lineage. The algorithm Ecotype Simulation identified sequence clusters consistent with ecologically distinct populations (ecotypes, and several hypothesized ecotypes were distinct in their habitat associations and in their adaptations to different microenvironments. We conclude that sexual isolation is more likely to follow ecological divergence than to precede it. Thus, an ecology-based model of speciation appears more appropriate than the biological species concept for bacterial and archaeal

  15. The role of local ecology during hybridization at the initial stages of ecological speciation in a marine snail.

    Science.gov (United States)

    Galindo, J; Martínez-Fernández, M; Rodríguez-Ramilo, S T; Rolán-Alvarez, E

    2013-07-01

    Hybrid zones of ecologically divergent populations are ideal systems to study the interaction between natural selection and gene flow during the initial stages of speciation. Here, we perform an amplified fragment length polymorphism (AFLP) genome scan in parallel hybrid zones between divergent ecotypes of the marine snail Littorina saxatilis, which is considered a model case for the study of ecological speciation. Ridged-Banded (RB) and Smooth-Unbanded (SU) ecotypes are adapted to different shore levels and microhabitats, although they present a sympatric distribution at the mid-shore where they meet and mate (partially assortatively). We used shell morphology, outlier and nonoutlier AFLP loci from RB, SU and hybrid specimens captured in sympatry to determine the level of phenotypic and genetic introgression. We found different levels of introgression at parallel hybrid zones and nonoutlier loci showed more gene flow with greater phenotypic introgression. These results were independent from the phylogeography of the studied populations, but not from the local ecological conditions. Genetic variation at outlier loci was highly correlated with phenotypic variation. In addition, we used the relationship between genetic and phenotypic variation to estimate the heritability of morphological traits and to identify potential Quantitative Trait Loci to be confirmed in future crosses. These results suggest that ecology (exogenous selection) plays an important role in this hybrid zone. Thus, ecologically based divergent natural selection is responsible, simultaneously, for both ecotype divergence and hybridization. On the other hand, genetic introgression occurs only at neutral loci (nonoutliers). In the future, genome-wide studies and controlled crosses would give more valuable information about this process of speciation in the face of gene flow.

  16. ECONOMIC VALUE OF SOME LEGUMINOUS PLANT SPECIES OF THE COLLECTIONS FROM THE BOTANICAL GARDEN (INSTITUTE OF THE ACADEMY OF SCIENCES OF MOLDOVA

    Directory of Open Access Journals (Sweden)

    Alexandru TELEUTA

    2016-12-01

    Full Text Available The results of the evaluation of the growth and development rates, the seed productivity, the green mass yield, the biochemical composition and the content of amino acids, phosphorous and calcium, the nutritive and energy value of the forage, as well as the biomethane productivity of local ecotypes of the leguminous species maintained in monoculture, in the collection of the Botanical Garden (Institute of the Academy of Sciences of Moldova (BG ASM: Astragalus ponticus, Coronilla varia, Lotus corniculatus, Medicago falcata, Onobrychis arenaria and Trifolium repens are presented in this article. Control variants – the traditional forage crops: Medicago sativa and Onobrychis viciifolia. The local ecotypes of the studied leguminous species were characterized by different growth and development rates. Coronilla varia and Lotus corniculatus, in the 2nd-3rd years, could be harvested, for the first time, 5 days earlier than Medicago sativa, but Medicago falcata and Onobrychis viciifolia – 18 days later. The green mass yield varied from 0.83 kg/m2 to 4.08 kg/m2. The studied ecotypes reached amounts of 0.60-0.89 nutritive units/kg and metabolizable energy 8.05-9.90 MJ/kg of dry matter, the content of digestible protein, of 106.28-225.09 g/nutritive unit, met the zootechnical standards; seed production: 19.12-83.00 g/m2; the biomethane yield ranged from 692 to 3197 m3/ha. Higher yield of natural forage, dry matter and biomethane was produced by Onobrychis arenaria and Coronilla varia.

  17. Genetic differentiation revealed by selective loci of drought-responding EST-SSRs between upland and lowland rice in China.

    Directory of Open Access Journals (Sweden)

    Hui Xia

    Full Text Available Upland and lowland rice (Oryza sativa L. represent two of the most important rice ecotypes adapted to ago-ecosystems with contrasting soil-water conditions. Upland rice, domesticated in the water-limited environment, contains valuable drought-resistant characters that can be used in water-saving breeding. Knowledge about the divergence between upland and lowland rice will provide valuable cues for the evolution of drought-resistance in rice. Genetic differentiation between upland and lowland rice was explored by 47 Simple Sequence Repeats (SSRs located in drought responding expressed sequence tags (ESTs among 377 rice landraces. The morphological traits of drought-resistance were evaluated in the field experiments. Different outlier loci were detected in the japonica and indica subspecies, respectively. Considerable genetic differentiation between upland and lowland rice on these outlier loci was estimated in japonica (Fst = 0.258 and indica (Fst = 0.127. Furthermore, populations of the upland and lowland ecotypes were clustered separately on these outlier loci. A significant correlation between genetic distance matrices and the dissimilarity matrices of drought-resistant traits was determined, indicating a certain relationship between the upland-lowland rice differentiation and the drought-resistance. Divergent selections occur between upland and lowland rice on the drought-resistance as the Qsts of some drought-resistant traits are significantly higher than the neutral Fst. In addition, the upland- and lowland-preferable alleles responded differently among ecotypes or allelic types under osmotic stress. This shows the evolutionary signature of drought resistance at the gene expression level. The findings of this study can strengthen our understanding of the evolution of drought-resistance in rice with significant implications in the improvement of rice drought-resistance.

  18. The radioecology of Pogonatum urnigerum (L. Pal. Beauv.

    Directory of Open Access Journals (Sweden)

    J. Sarosiek

    2015-01-01

    Full Text Available Within the area of the radiation anomaly near Kowary (Sudetes, the moss Pogonatum urnigerum grows on sites with natural gamma radiation of the soil within the limits of 0.05 to 0.91 mR/h. By way of detailed ecological analysis, five stenotopic habitats of P. urnigerum were singled out, differing, however, in radiation level. On these microhabitats the intrapopulation variability, radioactivity and ecological properties of the P. urnigerum populations were investigated. It was demonstrated that radiation within the above mentioned range is an essential ecological factor conditioning the ecotype differences in Pogonatum urnigerum, and among them the develop-mental anomalies.

  19. Radioecology of Picea excelsa (L. Lam

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    Jan Sarosiek

    2015-01-01

    Full Text Available Within the area of the radiation anomaly near Kowary (Sudeten Mountains the spruce (Picea excelsa occurs in habitats with natural soil gamma radiation within 0.05-1.48 mR/h. By way of detailed ecological analysis 5 stenotopic habitats of spruce development were selected differing in radiation intensity. In these habitats the intrapopulation variability, radioactivity and ecological properties of the Picea excelsa populations were investigated. It was demonstrated that radiation within the above mentioned range is an essential ecological limiting factor, conditioning ecotypic differences in Picea excelsa. The limiting influence of radiation is manifested in a high frequency of development anomalies in the spruce population.

  20. Genetic definition and sequence analysis of Arabidopsis centromeres.

    Science.gov (United States)

    Copenhaver, G P; Nickel, K; Kuromori, T; Benito, M I; Kaul, S; Lin, X; Bevan, M; Murphy, G; Harris, B; Parnell, L D; McCombie, W R; Martienssen, R A; Marra, M; Preuss, D

    1999-12-24

    High-precision genetic mapping was used to define the regions that contain centromere functions on each natural chromosome in Arabidopsis thaliana. These regions exhibited dramatic recombinational repression and contained complex DNA surrounding large arrays of 180-base pair repeats. Unexpectedly, the DNA within the centromeres was not merely structural but also encoded several expressed genes. The regions flanking the centromeres were densely populated by repetitive elements yet experienced normal levels of recombination. The genetically defined centromeres were well conserved among Arabidopsis ecotypes but displayed limited sequence homology between different chromosomes, excluding repetitive DNA. This investigation provides a platform for dissecting the role of individual sequences in centromeres in higher eukaryotes.

  1. Reference: 706 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available et al. 2008 Jan. Plant Cell Physiol. 49(1):2-10. To understand better the plant response to ozone, we isola...ted and characterized an ozone-sensitive (ozs1) mutant strain from a set of T-DNA-tagged Arabidopsis thalian...a ecotype Columbia. The mutant plants show enhanced sensitivity to ozone, desicca...vels. The T-DNA was inserted at a single locus which is linked to ozone sensitivity. Identification of the g...h either of two different T-DNA insertions in this gene were also sensitive to ozone, and these plants faile

  2. Farmers' breeding practices and traits of economic importance for indigenous chicken in RWANDA.

    Science.gov (United States)

    Mahoro, J; Muasya, T K; Mbuza, F; Mbuthia, J; Kahi, A K

    2017-09-26

    Data on breeding practices and traits of economic importance for the indigenous chicken (IC) were collected through personal interviews using structured questionnaires and direct observations of chicken management practices. The study was conducted from November 2015 to January 2016 in Rwamagana, Rulindo, Ruhango, Kicukiro and Muhanga districts of Rwanda. Data were collected and analysed through computation of indices, which represented a weighted average of all rankings of a specific trait. Spearman's non-parametric rank correlation was calculated for ranking of traits of economic importance to indicate the directional effects. The results on chicken ecotypes and their attributes showed that prolificacy, mature weight, disease tolerance, egg number and heat tolerance were highly preferred. The dwarf ecotype was most abundantly reared (38.84%) and considered to be significantly smaller and to have poorer growth rate, but to have better prolificacy than other indigenous chicken ecotypes. Selection of breeding cock and hen was based on disease tolerance, body weight at sexual maturity, body size and growth rate. In addition, for hen, mothering ability and egg fertility (Fer) were considered. Indices for the traits perceived by farmers as of primary economic importance were egg yield (0.093), disease tolerance (0.091), high growth rate (0.089), prolificacy (0.088), high body weight (0.087) and egg fertility (0.083). The most important traits considered by the marketers were body weight (BW), disease tolerance (Dtol), plumage colour (Pcol), egg yolk colour (EYC), meat quality (MQ), growth rate (GR) and egg yield (EY) whereas for consumers, meat quality, egg yolk colour, egg yield, body weight and growth rate were considered. Among traits perceived as important by farmers, a positive and significant correlation was found between BW and GR and Fer. Correlation was moderate for BW and prolificacy, drought tolerance (Drtol), Dtol and EYC. BW was negatively correlated with

  3. Comparative evolution history of SINEs in Arabidopsis thaliana and Brassica oleracea: evidence for a high rate of SINE loss.

    Science.gov (United States)

    Lenoir, A; Pélissier, T; Bousquet-Antonelli, C; Deragon, J M

    2005-01-01

    Brassica oleracea and Arabidopsis thaliana belong to the Brassicaceae(Cruciferae) family and diverged 16 to 19 million years ago. Although the genome size of B. oleracea (approximately 600 million base pairs) is more than four times that of A. thaliana (approximately 130 million base pairs), their gene content is believed to be very similar with more than 85% sequence identity in the coding region. Therefore, this important difference in genome size is likely to reflect a different rate of non-coding DNA accumulation. Transposable elements (TEs) constitute a major fraction of non-coding DNA in plant species. A different rate in TE accumulation between two closely related species can result in significant genome size variations in a short evolutionary period. Short interspersed elements (SINEs) are non-autonomous retroposons that have invaded the genome of most eukaryote species. Several SINE families are present in B. oleracea and A. thaliana and we found that two of them (called RathE1 and RathE2) are present in both species. In this study, the tempo of evolution of RathE1 and RathE2 SINE families in both species was compared. We observed that most B. oleracea RathE2 SINEs are "young" (close to the consensus sequence) and abundant while elements from this family are more degenerated and much less abundant in A. thaliana. However, the situation is different for the RathE1 SINE family for which the youngest elements are found in A. thaliana. Surprisingly, no SINE was found to occupy the same (orthologous) genomic locus in both species suggesting that either these SINE families were not amplified at a significant rate in the common ancestor of the two species or that older elements were lost and only the recent (lineage-specific) insertions remain. To test this latter hypothesis, loci containing a recently inserted SINE in the A. thaliana col-0 ecotype were selected and characterized in several other A. thaliana ecotypes. In addition to the expected SINE containing

  4. Regulation of nif gene expression and the energetics of N2 fixation over the diel cycle in a hot spring microbial mat

    DEFF Research Database (Denmark)

    Steunou, Anne-Soisig; Jensen, Sheila I; Brecht, Eric

    2008-01-01

    Nitrogen fixation, a prokaryotic, O(2)-inhibited process that reduces N(2) gas to biomass, is of paramount importance in biogeochemical cycling of nitrogen. We analyzed the levels of nif transcripts of Synechococcus ecotypes, NifH subunit and nitrogenase activity over the diel cycle...... in the microbial mat of an alkaline hot spring in Yellowstone National Park. The results showed a rise in nif transcripts in the evening, with a subsequent decline over the course of the night. In contrast, immunological data demonstrated that the level of the NifH polypeptide remained stable during the night...

  5. Genetic variation in ecoraces of tropical tasar silkworm, Antheraea mylitta using SSR marker

    Indian Academy of Sciences (India)

    G. RENUKA; G. SHAMITHA

    2016-12-01

    The tropical tasar silkworm, Antheraea mylitta, polyphagous sericigenous insect mostly found in the tropical areas of India. It is found in these regions as ecotypes or ecoraces. It feeds primarily on plants, a variety of secondary plants like Terminalia arjuna and T. tomentosa. Tasar culture is a traditional livelihood for lakhs of tribal populace in the areas of Jharkhand, Chhatisgarh, Orissa, Maharashtra, Andhra Pradesh, West Bengal and Uttar Pradesh. In the present study, the genetic diversity of these ecoraces is identified by DNA markers, namely simple sequence repeats (SSRs), most of which produced polymorphic bands.

  6. Transcriptional Regulation of Arabidopsis in Response to Salt Stress

    Institute of Scientific and Technical Information of China (English)

    Zhulong Chan

    2012-01-01

    Salt stress is a major factor limiting agricultural productivity worldwide.Adaptations to salt stress include avoidance by reduced sodium uptake,sequestration of toxic sodium ions away from the cytoplasm,or production of compatible solutes or osmoprotectants to reduce molecular disruption.Approaches to engineer salt stress resistance have included regulation of ion transport through introduction of Na+/H+ antiporter; synthesis of compatible solutes; or the introduction of transcription factors regulating expression of stress-responsive genes.On the other hand,naturally occurring variation among wild-type populations of plants also can be used to understand plant adaptive responses to their environments.In this study,we compared phenotypic and transcriptomic effects of constitutive expression of genes intended to confer salt stress tolerance by three different mechanisms:a transcription factor,CBF3/DREB1a; a metabolic gene,M6PR,for mannitol biosynthesis; and the Na+/H+ antiporter,SOS1.In the absence of salt,M6PR and SOS1 lines performed comparably with wild type; CBF3 lines exhibited dwarfing as reported previously.All three transgenes conferred fitness advantage when subjected to 100 mmol/L NaCI in the growth chamber.CBF3 and M6PR affected transcription of numerous abiotic stress-related genes as measured by Affymetrix microarray analysis.M6PR additionally modified expression of biotic stress and oxidative stress genes.Transcriptional effects of SOS1 were smaller and primarily limited to redox-related genes.In addition,we compared natural variations in salt tolerance between Ler and Sha ecotypes based on their responses to salt treatments and the results indicated that Ler was salt-sensitive,but Sha,which obtained a truncated RAS1 protein,was salt-tolerant.Transcriptome analysis revealed that many genes involved in secondary metabolism,photosynthesis,and protein synthesis were mainly down-regulated by salinity effects,while transposable element genes,microRNA and

  7. Codling Moth, Cydia pomonella (Lepidoptera: Tortricidae – Major Pest in Apple Production: an Overview of its Biology, Resistance, Genetic Structure and Control Strategies

    Directory of Open Access Journals (Sweden)

    Ivana Pajač

    2011-06-01

    Full Text Available The codling moth Cydia pomonella (CM (Linnaeus is a key pest in pome fruit production with a preference for apple. The pest is very adaptable to different climatic conditions and is known for developing resistance to several chemical groups of insecticides. Because of these reasons, the populations of codling moth are differentiated in many ecotypes of various biological and physiological development requirements. The article provides a bibliographic review of investigation about: morphology, biology, dispersal, damages, resistance to insecticides, population genetic structure and genetic control of this pest.

  8. The Effect of Freezing Stress on Percentage of Electrolytes Leakage and Survival of Flixweed (Descurainia sophia L. Seedlings

    Directory of Open Access Journals (Sweden)

    E Izadi-Darbandi

    2016-10-01

    Full Text Available Introduction Flixweed (Descurainia sophia L. is a medicinal plant from Brassicaceae family which also known as a weed for winter cereals and oil seed rape. Low temperatures are one of the most important abiotic stresses that threat Flixweed growth and productivity. Therefore it is important to recognize the freeze tolerance of Flixweed for successful planting and utilization in cold regions such as Mashhad in Khorasan Razavi Province (Iran’s north. east. Among many laboratory methods which have been developed to estimate and to evaluate plants response or their tolerance to freez¬ing temperatures, electrolyte leakage (EL test is widely used. This test is based on this principle that damage to the cell membranes results in enhanced leakage of solutes into the apoplastic water, hence recording the amount of leakage after stress treatments provides an estimation of tissue injury. Indeed continuing integration of plasma membrane is one important factor for survival of plants under freezing stress and any disturbance in membrane structure can lead to damage and death. So determination of LT50 point or critical temperature for electrolytes leakage and survival of plant is the most reliable, quantitative and simple methods for evaluating the cold tolerance of plants. The aim of this trial was to determine the LT50 according to the EL and SU% for Flixweed ecotypes. Materials and Methods In order to evaluate freeze tolerance in Flixweed, a factorial experiment based on completely randomized design with three replications was carried out in college of agriculture, Ferdowsi University of Mashhad. Experimental factors included five ecotypes of Flixweed (Eghlid, Sabzewar, Hamedan, Torbat-e-Jam and Neyshabour and 10 freezing temperature levels (0, -2,-4, -6, -8,-10,-12,-14,-16 and -18°C. Flixweed seeds were cultivated in pots in autumn of 2008 and were grown until 5-7 leaf stage under natural weather conditions for acclimation. Then to apply freezing

  9. Elevated CO2 concentration increase the mobility of Cd and Zn in the rhizosphere of hyperaccumulator Sedum alfredii.

    Science.gov (United States)

    Li, Tingqiang; Tao, Qi; Liang, Chengfeng; Yang, Xiaoe

    2014-05-01

    The effects of elevated CO2 on metal species and mobility in the rhizosphere of hyperaccumulator are not well understood. We report an experiment designed to compare the effects of elevated CO2 on Cd/Zn speciation and mobility in the rhizosphere of hyperaccumulating ecotype (HE) and a non-hyperaccumulating ecotype (NHE) of Sedum alfredii grown under ambient (350 μl l(-1)) or elevated (800 μl l(-1)) CO2 conditions. No difference in solution pH of NHE was observed between ambient and elevated CO2 treatments. For HE, however, elevated CO2 reduced soil solution pH by 0.22 unit, as compared to ambient CO2 conditions. Elevated CO2 increased dissolved organic carbon (DOC) and organic acid levels in soil solution of both ecotypes, but the increase in HE solution was much greater than in NHE solution. After the growth of HE, the concentrations of Cd and Zn in soil solution decreased significantly regardless of CO2 level. The visual MINTEQ speciation model predicted that Cd/Zn-DOM complexes were the dominant species in soil solutions, followed by free Cd(2+) and Zn(2+) species for both ecotypes. However, Cd/Zn-DOM complexes fraction in soil solution of HE was increased by the elevated CO2 treatment (by 8.01 % for Cd and 8.47 % for Zn, respectively). Resin equilibration experiment results indicated that DOM derived from the rhizosphere of HE under elevated CO2 (HE-DOM-E) (90 % for Cd and 73 % for Zn, respectively) showed greater ability to form complexes with Cd and Zn than those under ambient CO2 (HE-DOM-A) (82 % for Cd and 61 % for Zn, respectively) in the undiluted sample. HE-DOM-E showed greater ability to extract Cd and Zn from soil than HE-DOM-A. It was concluded that elevated CO2 could increase the mobility of Cd and Zn due to the enhanced formation of DOM-metal complexes in the rhizosphere of HE S. alfredii.

  10. Characterization of eds1, a mutation in Arabidopsis suppressing resistance to Peronospora parasitica specified by several different RPP genes.

    Science.gov (United States)

    Parker, J E; Holub, E B; Frost, L N; Falk, A; Gunn, N D; Daniels, M J

    1996-11-01

    The interaction between Arabidopsis and the biotrophic oomycete Peronospora parasitica (downy mildew) provides an attractive model pathosystem to identify molecular components of the host that are required for genotype-specific recognition of the parasite. These components are the so-called RPP genes (for resistance to P. parasitica). Mutational analysis of the ecotype Wassilewskija (Ws-0) revealed an RPP-nonspecific locus called EDS1 (for enhanced disease susceptibility) that is required for the function of RPP genes on chromosomes 3 (RPP1/RPP14 and RPP10) and 4 (RPP12). Genetic analyses demonstrated that the eds1 mutation is recessive and is not a defective allele of any known RPP gene, mapping to the bottom arm of chromosome 3 (approximately 13 centimorgans below RPP1/RPP14). Phenotypically, the Ws-eds1 mutant seedlings supported heavy sporulation by P. parasitica isolates that are each diagnostic for one of the RPP genes in wild-type Ws-0; none of the isolates is capable of sporulating on wild-type Ws-0. Ws-eds1 seedlings exhibited enhanced susceptibility to some P. parasitica isolates when compared with a compatible wild-type ecotype, Columbia, and the eds1 parental ecotype, Ws-0. This was observed as earlier initiation of sporulation and elevated production of conidiosporangia. Surprisingly, cotyledons of Ws-eds1 also supported low sporulation by five isolates of P. parasitica from Brassica oleracea. These isolates were unable to sporulate on > 100 ecotypes of Arabidopsis, including wild-type Ws-0. An isolate of Albugo candida (white blister) from B. oleracea also sporulated on Ws-eds1, but the mutant exhibited no alteration in phenotype when inoculated with several oomycete isolates from other host species. The bacterial resistance gene RPM1, conferring specific recognition of the avirulence gene avrB from Pseudomonas syringae pv glycinea, was not compromised in Ws-eds1 plants. The mutant also retained full responsiveness to the chemical inducer of systemic

  11. Research on genetics of rice heading date

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Heading date is one of the most important traits for rice adaptation to cultivation area and crop seasons, and it is mainly determined by photoperiod, basic vegetative growth, and temperature of cultivars. The diversity of combinations of photo-sensitive varieties and the basic vegetative, makes the heading date varied. On one hand, this supplies abundant resources for different ecotypes breeding; on the other hand, it complicates the inheritance of heading date. In recent years, transgression of late maturity has often been encountered, especially between indica and japonica subspecies, this had inhabited the use of hybrid vigor. Therefore, understanding the inheritance basis of heading date is very important for breeding practices.

  12. MORPHOLOGY AND PRODUCTIVITY OF “JUREMINHA” GENOTYPES (Desmanthus spp.) UNDER DIFFERENT CUTTING INTENSITIES

    OpenAIRE

    THIAGO BEZERRA CALADO; MÁRCIO VIEIRA DA CUNHA; VICENTE IMBROISI TEIXEIRA; MÉRCIA VIRGINIA FERREIRA DOS SANTOS; HACTUS SOUTO CAVALCANTI; CAROLINA CÂMARA LIRA

    2016-01-01

    The aim of the study was to evaluate the morphological and productive characteristics of five genotypes of Desmanthus spp. submitted to two cutting intensities (20 and 40 cm), in the semi-arid region of Pernambuco. Of the genotypes studied, three were derived from ecotypes collected in municipalities of Pernambuco (7G, 31D and 50J) and two were from the state of Sergipe, coming from Australia (10AU and 13AU). Four cuttings were made with a frequency of 60 days. The treatments were randomized ...

  13. Relationship between dry matter production and carbon dioxide absorption in seedlings of Scots pine (Pinus silvestris L. in their second vegetation season

    Directory of Open Access Journals (Sweden)

    W. Żelawski

    2015-01-01

    Full Text Available Accumulation of dry matter in needles, lignified stems and roots during the second vegetation season was compared with seasonal changes in photosynthesis and respiration activities of the se organs. Whereas growth analysis concerned plants growing at nearly natural course of external conditions, gas exchange determinations were made at constant laboratory conditions. For comparison of dry matter production and photosynthetic ability of a plant new terms „assimilation capacity" and „efficiency of assimilation" were introduced as possible expressions of photosynthetic productivity. Two ecotypes of Scots pine originating from lowland and highland regions of the country exhibited slightly different pattern of the investigated characteristics.

  14. The role of seasonal migration in the near-total loss of caribou on south-central Canadian Arctic Islands

    Directory of Open Access Journals (Sweden)

    Frank L. Miller

    2007-04-01

    Full Text Available Extended: In 1980 the caribou (Rangifer tarandus on Prince of Wales, Russell, and Somerset islands represented a healthy geographic population of an Arctic-island caribou ecotype on the southern tier of Canadian Arctic Islands. Those caribou exhibited complex patterns of seasonal range occupancy, involving annual seasonal migrations between and among the three islands and Boothia Peninsula (Miller et al., 1982, 2005; Miller, 1990. A large segment of the population migrated annually from the islands to Boothia Peninsula in early winter, wintered there, and then returned to the islands in the following late winter and spring. There is no evidence for large-scale emigration of caribou anywhere in the study area (Gunn et al., 2006. Caribou on Boothia Peninsula occur as two distinct ecotypes that are genetically different from the Arctic-island ecotype that occurred on Prince of Wales, Russell, and Somerset islands (e.g., Zittlau, 2004. Both the Boothia Peninsula ecotype and the Mainland ecotype calve mostly on northern Boothia Peninsula, northwest and northeast sections respectively (Gunn et al., 2000. After summering on the peninsula, most individuals of both ecotypes migrate south of the Boothia Isthmus onto adjacent mainland areas (Gunn et al., 2000. As a result, there were about the same number of caribou wintering on Boothia Peninsula when migrant caribou from Prince of Wales, Russell, and Somerset islands wintered there, as in summer when the migrant Arctic-island caribou had returned to Prince of Wales, Russell, and Somerset islands and the migrant Boothia Peninsula and Mainland caribou ecotypes had returned from their winter ranges farther south on the mainland to their calving areas and summer ranges on Boothia Peninsula. We treat both caribou ecotypes on Boothia Peninsula as just one geographic population for our assessment. The Arctic-island caribou ecotype on Prince of Wales, Russell, and Somerset islands declined about 98% from the

  15. Pomegranate (Punica granatum) juices: chemical composition, micronutrient cations, and antioxidant capacity.

    Science.gov (United States)

    El Kar, Chiraz; Ferchichi, Ali; Attia, Faouzi; Bouajila, Jalloul

    2011-08-01

    Phenolics, flavonoids, anthocyanins, and tannins of pomegranate juices, obtained from 9 Tunisian ecotypes were quantified. Phenolics and flavonoids in the variety Tounsi (TN) (3299 mg gallic acid equivalents [GAE]/L and 636 mg quercetin equivalents [QE]/L of juice, respectively) were higher than in the variety Gabsi (GB) (1570 mg GAE/L and 135 mg QE/L of juice, respectively). The highest anthocyanins quantity was found in GB 2 with 156 mg cyanidin-3-glucoside equivalents (CGE)/L. TN 3 ecotype showed the highest tannins quantity with 2550 mg catechin equivalents (CE)/L of juice. TN 1 presented the highest radical-scavenging activity (2, 2'-azinobis-3-ethylbenzothiazoline-6-sulphonate [ABTS], IC₅₀ [50% inhibition concentration] = 525 mg/L), as well as the highest concentration of micronutrient cations (potassium and sodium). A high correlation (R² = 0.80) between antioxidant capacity and proanthocyanin contents was found, this suggests that proanthocyanins are the principal contributor in the antioxidant capacity of pomegranate. Our data suggest also that the high concentrations of K⁺ and Na⁺ may play a role in the adaptation of pomegranate to arid environments.

  16. Colonization history and introduction dynamics of capsella bursa-pastoris (Brassicaceae) in north america: isozymes and quantitative traits

    Science.gov (United States)

    Neuffer; Hurka

    1999-10-01

    Multilocus isozyme genotypic composition for aspartate aminotransferase (AAT), leucine aminopeptidase (LAP) and glutamate dehydrogenase (GDH) was studied for Capsella in the source continent, Europe (9000 plants from 593 populations), and in the colonized continent, North America (2700 plants from 88 populations). North America was depauperate in the number of genotypes (by approximately 50%), but in terms of frequencies, a few genotypes were common and shared by both continents. Although some, very rare, genotypes were, however, unique for North America, our data provided no evidence to indicate that the introduced gene pools were reconstructed on a multilocus genetic basis after introduction. Instead, they argued for a considerable number of independent introduction events. Geographical distribution patterns of multilocus genotypes in Europe and North America were pronounced and enabled us to trace the colonization history of Californian Capsella back to Spanish ancestral populations and those of temperate North America back to temperate European gene pools. A random-block field experiment with 14 Californian populations from different climatic regions revealed that variation patterns of quantitative traits reflect ecotypic variation, and the ecological amplitude of Capsella in North America is similar to that in Europe, which can be traced back to the introduction of preadapted genotypes. It appears that certain multilocus isozyme genotypes are associated with certain ecotypes. The variable European gene pool of Capsella was essentially introduced into North America without major genetic changes.

  17. Seed origin and warming constrain lodgepole pine recruitment, slowing the pace of population range shifts

    Science.gov (United States)

    Conlisk, Erin; Castanha, Cristina; Germino, Matthew; Veblen, Thomas T.; Smith, Jeremy M.; Moyes, Andrew B.; Kueppers, Lara M.

    2017-01-01

    Understanding how climate warming will affect the demographic rates of different ecotypes is critical to predicting shifts in species distributions. Here we present results from a common garden, climate change experiment in which we measured seedling recruitment of lodgepole pine, a widespread North American conifer that is also planted globally. Seeds from a low-elevation provenance had greater recruitment to their third year (by 323%) than seeds from a high-elevation provenance across sites within and above its native elevation range and across climate manipulations. Heating reduced (by 49%) recruitment to the third year of both low- and high-elevation seed sources across the elevation gradient, while watering alleviated some of the negative effects of heating (108% increase in watered plots). Demographic models based on recruitment data from the climate manipulations and long-term observations of adult populations revealed that heating could effectively halt modeled upslope range expansion except when combined with watering. Simulating fire and rapid post-fire forest recovery at lower elevations accelerated lodgepole pine expansion into the alpine, but did not alter final abundance rankings among climate scenarios. Regardless of climate scenario, greater recruitment of low-elevation seeds compensated for longer dispersal distances to treeline, assuming colonization was allowed to proceed over multiple centuries. Our results show that ecotypes from lower elevations within a species’ range could enhance recruitment and facilitate upslope range shifts with climate change.

  18. Increased lead and cadmium tolerance of Typha angustifolia from Huaihe River is associated with enhanced phytochelatin synthesis and improved antioxidative capacity.

    Science.gov (United States)

    Liu, Yunlei; Chen, Jian; Lu, Shaonan; Yang, Libo; Qian, Jiazhong; Cao, Shuqing

    2016-11-01

    Heavy metal contamination of water is an increasing environmental problem worldwide, and the use of aquatic plants for phytoremediation of heavy metal pollution has become an important subject of research. One key to successful phytoremediation is the identification of plants that are efficient at sequestering heavy metals. In this study, we examined the growth and heavy metal accumulation of Typha angustifolia and compared growth characteristics and tolerance mechanisms in plants from the Huaihe and Chaohu Rivers irrigated with different concentrations of lead (Pb) and cadmium (Cd). T. angustifolia from Huaihe River showed enhanced tolerance and accumulation of Pb and Cd and had greater biomass and more vigorous growth than the ecotype from Chaohu River. In addition, higher phytochelatin (PC) content and significantly higher superoxide dismutase and catalase activities were detected in T. angustifolia from Huaihe River than in T. angustifolia from Chaohu River. These findings suggest that high Pb and Cd accumulation and tolerance in T. angustifolia from Chaohu River is associated with its higher PC synthesis and better antioxidative capacity, and that the Huaihe ecotype of T. angustifolia might also be an efficient species for phytoremediation of Pb and Cd in water contaminated by heavy metals.

  19. Physiological and molecular evidence of differential short-term heat tolerance in Mediterranean seagrasses

    Science.gov (United States)

    Marín-Guirao, Lazaro; Ruiz, Juan M.; Dattolo, Emanuela; Garcia-Munoz, Rocio; Procaccini, Gabriele

    2016-06-01

    The increase in extreme heat events associated to global warming threatens seagrass ecosystems, likely by affecting key plant physiological processes such as photosynthesis and respiration. Understanding species’ ability to acclimate to warming is crucial to better predict their future trends. Here, we study tolerance to warming in two key Mediterranean seagrasses, Posidonia oceanica and Cymodocea nodosa. Stress responses of shallow and deep plants were followed during and after short-term heat exposure in mesocosms by coupling photo-physiological measures with analysis of expression of photosynthesis and stress-related genes. Contrasting tolerance and capacity to heat acclimation were shown by shallow and deep P. oceanica ecotypes. While shallow plants acclimated through respiratory homeostasis and activation of photo-protective mechanisms, deep ones experienced photosynthetic injury and impaired carbon balance. This suggests that P. oceanica ecotypes are thermally adapted to local conditions and that Mediterranean warming will likely diversely affect deep and shallow meadow stands. On the other hand, contrasting mechanisms of heat-acclimation were adopted by the two species. P. oceanica regulates photosynthesis and respiration at the level of control plants while C. nodosa balances both processes at enhanced rates. These acclimation discrepancies are discussed in relation to inherent attributes of the two species.

  20. Study on Relationship Between Cucumber Germplasm and Propa-mocarb Residue Using Subjective Rating Technique

    Institute of Scientific and Technical Information of China (English)

    Wu Peng; Qin Zhi-wei; Zhou Xiu-yan; Wu Tao; Xin Ming; Guo Qian-qian

    2014-01-01

    Propamocarb (PM) residue in cucumber (Cucumis sativus L.) receives little attention. As is well known to all, high PM residue of cucumber could lead to increase in the violation rates of maximum residue limits and ultimately cause harm to human health. Knowledge of PM residue could help cucumber breeders in developing cultivars with low PM residue and improving cucumber quality. In this study, 32 representative cucumber accessions (26 breeding lines and six cultivars) from different regions of China were evaluated for their PM residue in fruit and leaf to provide meaning to the subjective rating, which was highly correlated with PM residual content of fruit (r=0.97) and leaf (r=0.94). In addition, PM residual content of North China ecotype was the highest and Pickling ecotype was the lowest in fruit and leaf of cucumber. The leaf had significantly higher (P<0.01) PM residual content than the fruit, and poor correlation between leaf and fruit was represented. This study verified PM residual relationship between fruit and leaf, and laid the foundation for further identification of germplasm resources and breeding of new varieties for low PM residue of cucumber.

  1. Epigenetic natural variation in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Matthew W Vaughn

    2007-07-01

    Full Text Available Cytosine methylation of repetitive sequences is widespread in plant genomes, occurring in both symmetric (CpG and CpNpG as well as asymmetric sequence contexts. We used the methylation-dependent restriction enzyme McrBC to profile methylated DNA using tiling microarrays of Arabidopsis Chromosome 4 in two distinct ecotypes, Columbia and Landsberg erecta. We also used comparative genome hybridization to profile copy number polymorphisms. Repeated sequences and transposable elements (TEs, especially long terminal repeat retrotransposons, are densely methylated, but one third of genes also have low but detectable methylation in their transcribed regions. While TEs are almost always methylated, genic methylation is highly polymorphic, with half of all methylated genes being methylated in only one of the two ecotypes. A survey of loci in 96 Arabidopsis accessions revealed a similar degree of methylation polymorphism. Within-gene methylation is heritable, but is lost at a high frequency in segregating F(2 families. Promoter methylation is rare, and gene expression is not generally affected by differences in DNA methylation. Small interfering RNA are preferentially associated with methylated TEs, but not with methylated genes, indicating that most genic methylation is not guided by small interfering RNA. This may account for the instability of gene methylation, if occasional failure of maintenance methylation cannot be restored by other means.

  2. Epigenetic natural variation in Arabidopsis thaliana.

    Science.gov (United States)

    Vaughn, Matthew W; Tanurdzić, Milos; Lippman, Zachary; Jiang, Hongmei; Carrasquillo, Robert; Rabinowicz, Pablo D; Dedhia, Neilay; McCombie, W Richard; Agier, Nicolas; Bulski, Agnès; Colot, Vincent; Doerge, R W; Martienssen, Robert A

    2007-07-01

    Cytosine methylation of repetitive sequences is widespread in plant genomes, occurring in both symmetric (CpG and CpNpG) as well as asymmetric sequence contexts. We used the methylation-dependent restriction enzyme McrBC to profile methylated DNA using tiling microarrays of Arabidopsis Chromosome 4 in two distinct ecotypes, Columbia and Landsberg erecta. We also used comparative genome hybridization to profile copy number polymorphisms. Repeated sequences and transposable elements (TEs), especially long terminal repeat retrotransposons, are densely methylated, but one third of genes also have low but detectable methylation in their transcribed regions. While TEs are almost always methylated, genic methylation is highly polymorphic, with half of all methylated genes being methylated in only one of the two ecotypes. A survey of loci in 96 Arabidopsis accessions revealed a similar degree of methylation polymorphism. Within-gene methylation is heritable, but is lost at a high frequency in segregating F(2) families. Promoter methylation is rare, and gene expression is not generally affected by differences in DNA methylation. Small interfering RNA are preferentially associated with methylated TEs, but not with methylated genes, indicating that most genic methylation is not guided by small interfering RNA. This may account for the instability of gene methylation, if occasional failure of maintenance methylation cannot be restored by other means.

  3. Effects of diapause and cold-acclimation on the avoidance of freezing injury in fat body tissue of the rice stem borer, Chilo suppressalis Walker.

    Science.gov (United States)

    Izumi, Yohei; Sonoda, Shoji; Tsumuki, Hisaaki

    2007-07-01

    Overwintering freeze-tolerant larvae of Chilo suppressalis can survive at -25 degrees C, but non-diapausing larvae cannot. We reported earlier that to prevent intracellular freezing, which causes death in overwintering larvae of the Saigoku ecotype distributed in southwestern Japan, water leaves and glycerol enters fat body cells through water channels during freezing. However, it is still unclear how diapause and low-temperature exposure are related to the acquisition of freeze tolerance. We compared the extent of tissue damage, accumulation of glycerol, and transport of glycerol and water in fat body tissues between cold-acclimated and non-acclimated non-diapausing and diapausing larvae. The tissue from cold-acclimated diapausing larvae could survive only when frozen in Grace's insect medium with 0.25 M glycerol at -20 degrees C. The protection provided by glycerol was offset by mercuric chloride, which is a water-channel inhibitor. Fat body tissue isolated from non-acclimated diapausing larvae was injured by freezing even though glycerol was added to the medium, but the level of freezing injury was significantly lower than in non-diapausing larvae. Radiotracer assays in cold-acclimated diapausing larvae showed that during freezing, water left the cells into the medium and glycerol entered the cells from the medium at the same time. Therefore, in Saigoku ecotype larvae of the rice stem borer, both diapause and cold-acclimation are essential to accumulate glycerol and activate aquaporin for the avoidance of freezing injury.

  4. Culturable heterotrophic bacteria from the marine sponge Dendrilla nigra: isolation and phylogenetic diversity of actinobacteria

    Science.gov (United States)

    Selvin, Joseph; Gandhimathi, R.; Kiran, G. Seghal; Priya, S. Shanmugha; Ravji, T. Rajeetha; Hema, T. A.

    2009-09-01

    Culturable heterotrophic bacterial composition of marine sponge Dendrilla nigra was analysed using different enrichments. Five media compositions including without enrichment (control), enriched with sponge extract, with growth regulator (antibiotics), with autoinducers, and complete enrichment containing sponge extract, antibiotics, and autoinducers were developed. DNA hybridization assay was performed to explore host specific bacteria and ecotypes of culturable sponge-associated bacteria. Enrichment with selective inducers (AHLs and sponge extract) and regulators (antibiotics) considerably enhanced the cultivation potential of sponge-associated bacteria. It was found that Marinobacter (MSI032), Micromonospora (MSI033), Streptomyces (MSI051), and Pseudomonas (MSI057) were sponge-associated obligate symbionts. The present findings envisaged that “ Micromonospora-Saccharomonospora-Streptomyces” group was the major culturable actinobacteria in the marine sponge D. nigra. The DNA hybridization assay was a reliable method for the analysis of culturable bacterial community in marine sponges. Based on the culturable community structure, the sponge-associated bacteria can be grouped (ecotypes) as general symbionts, specific symbionts, habitat flora, and antagonists.

  5. Diversity of arbuscular mycorrhizal fungus populations in heavy-metal-contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Del Val, C.; Barea, J.M.; Azcon-Aguilar, C. [CSIC, Granada (Spain)

    1999-02-01

    High concentrations of heavy metals have been shown to adversely affect the size, diversity, and activity of microbial populations in soil. The aim of this work was to determine how the diversity of arbuscular mycorrhizal (AM) fungi is affected by the addition of sewage-amended sludge containing heavy metals in a long-term experiment. Due to the reduced number of indigenous AM fungal (AMF) propagules in the experimental soils, several host plants with different life cycles were used to multiply indigenous fungi. Six AMF ecotypes were found in the experimental soils, showing consistent differences with regard to their tolerance to the presence of heavy metals. AMF ecotypes ranged from very sensitive to the presence of metals to relatively tolerant to high rates of heavy metals in soil. Total AMF spore numbers decreased with increasing amounts of heavy metals in the soil. However, species richness and diversity as measured by the Shannon-Wiener index increased in soils receiving intermediate rates of sludge contamination but decreased in soils receiving the highest rate of heavy-metal-contaminated sludge. Relative densities of most AMF species were also significantly influenced by soil treatments. Host plant species exerted a selective influence on AMF population size and diversity. The authors conclude based on the results of this study that size and diversity of AMF populations were modified in metal-polluted soils, even in those with metal concentrations that were below the upper limits accepted by the European Union for agricultural soils.

  6. Quantitative divergence of the bacterial root microbiota in Arabidopsis thaliana relatives.

    Science.gov (United States)

    Schlaeppi, Klaus; Dombrowski, Nina; Oter, Ruben Garrido; Ver Loren van Themaat, Emiel; Schulze-Lefert, Paul

    2014-01-14

    Plants host at the contact zone with soil a distinctive root-associated bacterial microbiota believed to function in plant nutrition and health. We investigated the diversity of the root microbiota within a phylogenetic framework of hosts: three Arabidopsis thaliana ecotypes along with its sister species Arabidopsis halleri and Arabidopsis lyrata, as well as Cardamine hirsuta, which diverged from the former ∼ 35 Mya. We surveyed their microbiota under controlled environmental conditions and of A. thaliana and C. hirsuta in two natural habitats. Deep 16S rRNA gene profiling of root and corresponding soil samples identified a total of 237 quantifiable bacterial ribotypes, of which an average of 73 community members were enriched in roots. The composition of this root microbiota depends more on interactions with the environment than with host species. Interhost species microbiota diversity is largely quantitative and is greater between the three Arabidopsis species than the three A. thaliana ecotypes. Host species-specific microbiota were identified at the levels of individual community members, taxonomic groups, and whole root communities. Most of these signatures were observed in the phylogenetically distant C. hirsuta. However, the branching order of host phylogeny is incongruent with interspecies root microbiota diversity, indicating that host phylogenetic distance alone cannot explain root microbiota diversification. Our work reveals within 35 My of host divergence a largely conserved and taxonomically narrow root microbiota, which comprises stable community members belonging to the Actinomycetales, Burkholderiales, and Flavobacteriales.

  7. Character displacement and the evolution of niche complementarity in a model biofilm community.

    Science.gov (United States)

    Ellis, Crystal N; Traverse, Charles C; Mayo-Smith, Leslie; Buskirk, Sean W; Cooper, Vaughn S

    2015-02-01

    Colonization of vacant environments may catalyze adaptive diversification and be followed by competition within the nascent community. How these interactions ultimately stabilize and affect productivity are central problems in evolutionary ecology. Diversity can emerge by character displacement, in which selection favors phenotypes that exploit an alternative resource and reduce competition, or by facilitation, in which organisms change the environment and enable different genotypes or species to become established. We previously developed a model of long-term experimental evolution in which bacteria attach to a plastic bead, form a biofilm, and disperse to a new bead. Here, we focus on the evolution of coexisting mutants within a population of Burkholderia cenocepacia and how their interactions affected productivity. Adaptive mutants initially competed for space, but later competition declined, consistent with character displacement and the predicted effects of the evolved mutations. The community reached a stable equilibrium as each ecotype evolved to inhabit distinct, complementary regions of the biofilm. Interactions among ecotypes ultimately became facilitative and enhanced mixed productivity. Observing the succession of genotypes within niches illuminated changing selective forces within the community, including a fundamental role for genotypes producing small colony variants that underpin chronic infections caused by B. cenocepacia.

  8. The relationship between diaspore characteristics with phylogeny, life history traits, and their ecological adaptation of 150 species from the cold desert of Northwest China.