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Sample records for hybrid helianthus species

  1. Characterization of F1 interspecific hybrids between wild Helianthus annuus L. populations and cultivated sunflower

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    Terzić Sreten

    2006-01-01

    Full Text Available Phenotype, chromosomes pairing and pollen vitality were compared between parental populations and F1 hybrids of interspecific cross between Helianthus annuus L. and cultivated sunflower. The investigation of the simple sequence repeats (SSR polymorphism was also used to test the hybrid nature of F1 populations. The phenotypic traits of F1 hybrid plants were either closer to the wild species or intermediate. Irregular chromosome pairing was found in only 0 to 10% of meiocytes in the meiosis of F1 hybrid plants. Interspecific crosses were confirmed with SSR markers in all hybrid combinations. Alleles that were not present in parental DNA were frequently observed in F1 hybrids. That is additional evidence that those hybrid combinations were not produced by self-fertilization. The results suggest that SSR markers can be efficiently used for the F1 hybrid characterization in crosses between closely related species, in which, the changes of phenotype, meiosis and pollen vitality are not always significant.

  2. Breaking tuber dormancy in Helianthus tuberosus L. and interspecific hybrids of Helianthus annuus L. x Helianthus tuberosus

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    Helianthus tuberosus L. tubers are dormant from the late fall to the following spring. In the wild, tuber dormancy is broken after exposure to winter cold, resulting in sprouting and shoot development in the spring when environmental conditions are favorable. The dormancy period typically limits H. ...

  3. Reconstructing the origin of Helianthus deserticola: Survival and selection on the desert floor

    NARCIS (Netherlands)

    Gross, B.L.; Kane, D.L.; Lexer, C.; Ludwig, F.; Rosenthal, D.R.; Donovan, L.A.; Rieseberg, L.H.

    2004-01-01

    The diploid hybrid species Helianthus deserticola inhabits the desert floor, an extreme environment relative to its parental species Helianthus annuus and Helianthus petiolaris. Adaptation to the desert floor may have occurred via selection acting on transgressive, or extreme, traits in early hybrid

  4. Reconstructing the origin of Helianthus deserticola: Survival and selection on the desert floor

    NARCIS (Netherlands)

    Gross, B.L.; Kane, D.L.; Lexer, C.; Ludwig, F.; Rosenthal, D.R.; Donovan, L.A.; Rieseberg, L.H.

    2004-01-01

    The diploid hybrid species Helianthus deserticola inhabits the desert floor, an extreme environment relative to its parental species Helianthus annuus and Helianthus petiolaris. Adaptation to the desert floor may have occurred via selection acting on transgressive, or extreme, traits in early

  5. Phylogeny of Helianthus and related genera

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    Schilling Edward E.

    2001-01-01

    Full Text Available Molecular phylogenetic studies have contributed significantly to our understanding of the phylogenetic relationships of Helianthus, although several problems remain to be resolved. Molecular data have resolved problems with the circumscription of Helianthus. Its sister group is Phoebanthus, a narrowly distributed genus of two species from the state of Florida. The sister group to the Helianthus-Phoebanthus clade is a diverse set of taxa that occurs in Mexico and South America. These include species now classified as part of the paraphyletic Viguiera as well as such distinctive genera as Tithonia, Simsia, Pappobolus, Scalesia, Lagascea, and Alvordia. Incongruence between results based on chloroplast and nuclear-based data sets suggests that hybridization has been involved in the evolutionary history of this group. The nearest outgroup to the clade containing Helianthus is composed of members of Viguiera sect. Maculatae, which are trees and shrubs of Mexico. Other basally diverging groups in the subtribe Helianthinae to which Helianthus belongs are primarily woody members now classified in Viguiera from Mexico and nearby areas. Within Helianthus, divergence appears to be recent, based on an overall lack of divergence between species. The chloroplast-based tree suggests that Helianthus includes four phylogenetic lineages, whereas the nuclear ITS sequence data suggests that the perennial species are paraphyletic relative to the rest of the genus, with basally diverging branches consisting of species confined to the southeastern US. Because there is a lack of divergence among many groups of species, more variable markers will be required to resolve fully relationships within Helianthus.

  6. Ontogeny strongly and differentially alters leaf economic and other key traits in three diverse Helianthus species.

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    Mason, Chase M; McGaughey, Sarah E; Donovan, Lisa A

    2013-10-01

    The leaf economics spectrum (LES) describes large cross-species variation in suites of leaf functional traits ranging from resource-acquisitive to resource-conservative strategies. Such strategies have been integral in explaining plant adaptation to diverse environments, and have been linked to numerous ecosystem processes. The LES has previously been found to be significantly modulated by climate, soil fertility, biogeography, growth form, and life history. One largely unexplored aspect of LES variation, whole-plant ontogeny, is investigated here using multiple populations of three very different species of sunflower: Helianthus annuus, Helianthus mollis, and Helianthus radula. Plants were grown under environmentally controlled conditions and assessed for LES and related traits at four key developmental stages, using recently matured leaves to standardize for leaf age. Nearly every trait exhibited a significant ontogenetic shift in one or more species, with trait patterns differing among populations and species. Photosynthetic rate, leaf nitrogen concentration, and leaf mass per area exhibited surprisingly large changes, spanning over two-thirds of the original cross-species LES variation and shifting from resource-acquisitive to resource-conservative strategies as the plants matured. Other traits being investigated in relation to the LES, such as leaf water content, pH, and vein density, also showed large changes. The finding that ontogenetic variation in LES strategy can be substantial leads to a recommendation of standardization by developmental stage when assessing 'species values' of labile traits for comparative approaches. Additionally, the substantial ontogenetic trait shifts seen within single individuals provide an opportunity to uncover the contribution of gene regulatory changes to variation in LES traits.

  7. Evolutionary Divergences in Root Exudate Composition among Ecologically-Contrasting Helianthus Species.

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    Bowsher, Alan W; Ali, Rifhat; Harding, Scott A; Tsai, Chung-Jui; Donovan, Lisa A

    2016-01-01

    Plant roots exude numerous metabolites into the soil that influence nutrient availability. Although root exudate composition is hypothesized to be under selection in low fertility soils, few studies have tested this hypothesis in a phylogenetic framework. In this study, we examined root exudates of three pairs of Helianthus species chosen as phylogenetically-independent contrasts with respect to native soil nutrient availability. Under controlled environmental conditions, seedlings were grown to the three-leaf-pair stage, then transferred to either high or low nutrient treatments. After five days of nutrient treatments, we used gas chromatography-mass spectrometry for analysis of root exudates, and detected 37 metabolites across species. When compared in the high nutrient treatment, species native to low nutrient soils exhibited overall higher exudation than their sister species native to high nutrient soils in all three species pairs, providing support for repeated evolutionary shifts in response to native soil fertility. Species native to low nutrient soils and those native to high nutrient soils responded similarly to low nutrient treatments with increased exudation of organic acids (fumaric, citric, malic acids) and glucose, potentially as a mechanism to enhance nutrition acquisition. However, species native to low nutrient soils also responded to low nutrient treatments with a larger decrease in exudation of amino acids than species native to high nutrient soils in all three species pairs. This indicates that species native to low nutrient soils have evolved a unique sensitivity to changes in nutrient availability for some, but not all, root exudates. Overall, these repeated evolutionary divergences between species native to low nutrient soils and those native to high nutrient soils provide evidence for the adaptive value of root exudation, and its plasticity, in contrasting soil environments.

  8. Phenotypic selection on leaf ecophysiological traits in Helianthus

    NARCIS (Netherlands)

    Donovan, L.A.; Ludwig, F.; Rosenthal, D.R.; Rieseberg, L.H.; Dudley, S.A.

    2009-01-01

    Habitats that differ in soil resource availability are expected to differ for selection on resource-related plant traits. Here, we examined spatial and temporal variation in phenotypic selection on leaf ecophysiological traits for 10 Helianthus populations, including two species of hybrid origin, He

  9. Genotyping-by-Sequencing Uncovers the Introgression Alien Segments Associated with Sclerotinia Basal Stalk Rot Resistance from Wild Species-I. Helianthus argophyllus and H. petiolaris.

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    Qi, Lili; Long, Yunming; Talukder, Zahirul I; Seiler, Gerald J; Block, Charles C; Gulya, Thomas J

    2016-01-01

    Basal stalk rot (BSR), caused by Sclerotinia sclerotiorum, is a devastating disease in sunflower worldwide. The progress of breeding for Sclerotinia BSR resistance has been hampered due to the lack of effective sources of resistance for cultivated sunflower. Our objective was to transfer BSR resistance from wild annual Helianthus species into cultivated sunflower and identify the introgressed alien segments associated with BSR resistance using a genotyping-by-sequencing (GBS) approach. The initial crosses were made between the nuclear male sterile HA 89 with the BSR resistant plants selected from wild Helianthus argophyllus and H. petiolaris populations in 2009. The selected resistant F1 plants were backcrossed to HA 458 and HA 89, respectively. Early generation evaluations of BSR resistance were conducted in the greenhouse, while the BC2F3 and subsequent generations were evaluated in the inoculated field nurseries. Eight introgression lines; six from H. argophyllus (H.arg 1 to H.arg 6), and two from H. petiolaris (H.pet 1 and H.pet 2), were selected. These lines consistently showed high levels of BSR resistance across seven environments from 2012 to 2015 in North Dakota and Minnesota, USA. The mean BSR disease incidence (DI) for H.arg 1 to H.arg 6, H.pet 1, and H.pet 2 was 3.0, 3.2, 0.8, 7.2, 7.7, 1.9, 2.5, and 4.4%, compared to a mean DI of 36.1% for Cargill 270 (susceptible hybrid), 31.0% for HA 89 (recurrent parent), 19.5% for HA 441 (resistant inbred), and 11.6% for Croplan 305 (resistant hybrid). Genotyping of the highly BSR resistant introgression lines using GBS revealed the presence of the H. argophyllus segments in linkage groups (LGs) 3, 8, 9, 10, and 11 of the sunflower genome, and the H. petiolaris segments only in LG8. The shared polymorphic SNP loci in the introgression lines were detected in LGs 8, 9, 10, and 11, indicating the common introgression regions potentially associated with BSR resistance. Additionally, a downy mildew resistance gene, Pl17

  10. Genetic analysis of agro-morphological traits in promising hybrids of sunflower (Helianthus annuus L.

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    Maryam GOLABADI

    2015-11-01

    Full Text Available The main objective underlying sunflower breeding programs is to develop high-yielding productive F1 hybrid cultivars. This study was conducted to investigate the genetic control of some agro-morphological traits of new sunflower F1 hybrids. For this purpose, fourteen inbred lines of sunflower were crossed with three male sterile inbred lines. Their hybrids (14 hybrids were then evaluated against three control cultivars. The data thus obtained were analyzed using the nested model (North Carolina Design І as a completely randomized block design (CRBD with four replications. Analysis of variance showed that the hybrids were significantly different in all the traits studied, except for head and stem diameters. From among the hybrids evaluated, Cms19 × Rn1-81 was found to have the highest seed yield and oil content. Cluster analysis classified the hybrids into four different groups. Genetic analysis showed that days to maturity, seed weight, and oil content (% were under the additive gene action. Breeding strategies based on selection could be suggested for the improvement of these traits. Head angle, head diameter, seed yield, and oil yield were under the dominance gene action; breeding based on hybridization methods is, therefore, proposed for these traits. Finally, both additive and dominance gene actions were observed to play important roles in the genetic control of plant height and stem diameter.

  11. Nitrogen and phosphorus management strategy for better growth and yield of sunflower (Helianthus annuus L. hybrid

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    Amjed Ali and Ijaz Rasool Noorka

    2013-05-01

    Full Text Available This study conducted during autumn season, 2010 investigated the effect of nitrogen and phosphorus on sunflower hybrid Hysun-33. The experiment was planned in randomized complete block design (factorial arrangement, with three replication, having net plot size of 3 x 7 m. The experiment comprised of 9 treatments, three levels of nitrogen and phosphorus, viz., 85, 135, 185 kg N ha-1, and 50, 75, 85 kg P ha-1. Nitrogen affected all estimated characters significantly, except plant population, while, phosphorus did not show significant effect on plant population and plant height. All other parameters, as leaf area plant-1, head diameter, 1000- achene weight and achene yield were affected significantly by different nitrogen and phosphorus levels. Interactive effects of nitrogen and phosphorus were significant in all these cases. The highest achene’s yield (2584 kg ha-1 was obtained with the application of 135-75 kg NP ha-1as against the lowest (1491kg ha-1 at 85-50 kg NP ha-1.

  12. Analysis of transposons and repeat composition of the sunflower (Helianthus annuus L.) genome.

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    Cavallini, Andrea; Natali, Lucia; Zuccolo, Andrea; Giordani, Tommaso; Jurman, Irena; Ferrillo, Veronica; Vitacolonna, Nicola; Sarri, Vania; Cattonaro, Federica; Ceccarelli, Marilena; Cionini, Pier Giorgio; Morgante, Michele

    2010-02-01

    A sample-sequencing strategy combined with slot-blot hybridization and FISH was used to study the composition of the repetitive component of the sunflower genome. One thousand six hundred thirty-eight sequences for a total of 954,517 bp were analyzed. The fraction of sequences that can be classified as repetitive using computational and hybridization approaches amounts to 62% in total. Almost two thirds remain as yet uncharacterized in nature. Of those characterized, most belong to the gypsy superfamily of LTR-retrotransposons. Unlike in other species, where single families can account for large fractions of the genome, it appears that no transposon family has been amplified to very high levels in sunflower. All other known classes of transposable elements were also found. One family of unknown nature (contig 61) was the most repeated in the sunflower genome. The evolution of the repetitive component in the Helianthus genus and in other Asteraceae was studied by comparative analysis of the hybridization of total genomic DNAs from these species to the sunflower small-insert library and compared to gene-based phylogeny. Very little similarity is observed between Helianthus species and two related Asteraceae species outside of the genus. Most repetitive elements are similar in annual and perennial Helianthus species indicating that sequence amplification largely predates such divergence. Gypsy-like elements are more represented in the annuals than in the perennials, while copia-like elements are similarly represented, attesting a different amplification history of the two superfamilies of LTR-retrotransposons in the Helianthus genus.

  13. Sunflower (Helianthus annuus L.).

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    Radonic, Laura M; Lewi, Dalia M; López, Nilda E; Hopp, H Esteban; Escandón, Alejandro S; Bilbao, Marisa López

    2015-01-01

    Sunflower (Helianthus annuus L.) is still considered as a recalcitrant species to in vitro culture and transformation in spite of the publication of different protocols. Here we describe a routine transformation system of this crop which requires mature HA89 genotype seeds and Agrobacterium tumefaciens EHA105 strain for gene delivery, being both easily available. Selection of transformed shoots depends on root development in kanamycin-selective media, instead of shoot color, avoiding selection of escapes. The establishment of this protocol proved successful for the incorporation of both reporter and agronomic important genes and also for the evaluation of the specific expression patterns of different promoters in transgenic sunflower plants. Stable expression of the incorporated transgenes was confirmed by RT-PCR and GUS reporter gene visualization. Stable inheritance of transgenes was successfully followed until T2 generation in several independent lines.

  14. Species hybridization in the genus Pinus

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    Peter W. Garrett

    1979-01-01

    Results of a breeding program in which a large number of pine species were tested indicate that a number of species and hybrids may be useful in the northeastern United States. Austrian black pine x Japanese black pine and hybrids containing Japanese red pine all had good growth rates. While none of the soft pines grew faster than eastern white pine, a number of...

  15. Genetic variability in sunflower (Helianthus annuus L.) and in the Helianthus genus as assessed by retrotransposon-based molecular markers.

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    Vukich, M; Schulman, A H; Giordani, T; Natali, L; Kalendar, R; Cavallini, A

    2009-10-01

    The inter-retrotransposon amplified polymorphism (IRAP) protocol was applied for the first time within the genus Helianthus to assess intraspecific variability based on retrotransposon sequences among 36 wild accessions and 26 cultivars of Helianthus annuus L., and interspecific variability among 39 species of Helianthus. Two groups of LTRs, one belonging to a Copia-like retroelement and the other to a putative retrotransposon of unknown nature (SURE) have been isolated, sequenced and primers were designed to obtain IRAP fingerprints. The number of polymorphic bands in H. annuus wild accessions is as high as in Helianthus species. If we assume that a polymorphic band can be related to a retrotransposon insertion, this result suggests that retrotransposon activity continued after Helianthus speciation. Calculation of similarity indices from binary matrices (Shannon's and Jaccard's indices) show that variability is reduced among domesticated H. annuus. On the contrary, similarity indices among Helianthus species were as large as those observed among wild H. annuus accessions, probably related to their scattered geographic distribution. Principal component analysis of IRAP fingerprints allows the distinction between perennial and annual Helianthus species especially when the SURE element is concerned.

  16. Triploid Production from Interspecific Crosses of Two Diploid Perennial Helianthus with Diploid Cultivated Sunflower (Helianthus annuus L.)

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    Liu, Zhao; Seiler, Gerald J.; Gulya, Thomas J.; Feng, Jiuhuan; Rashid, Khalid Y.; Cai, Xiwen; Jan, Chao-Chien

    2017-01-01

    Wild Helianthus species are a valuable genetic resource for the improvement of cultivated sunflower. We report the discovery and characterization of a unique high frequency production of triploids when cultivated sunflower was pollinated by specific accessions of diploid Helianthus nuttallii T. & G. and H. maximiliani Schr. Genomic in situ hybridization (GISH) analyses indicated that the triploid F1s had two genomes from the wild pollen sources and one from the cultivated line. Mitotic chromosome analyses indicated that the frequency of triploid progenies from the crosses of cultivated lines × H. nuttallii accession 102 (N102) was significantly higher than those of unexpected polyploid progenies from the crosses of wild perennial species × N102, and no unexpected polyploids were obtained from the reverse crosses. Pollen stainability analysis suggested the existence of a low percentage of unreduced (2n) male gametes in some accessions, especially N102 and H. maximiliani accession 1113 (M1113), which were generated at the telophase II and tetrad stages of meiosis. The triploid F1s could be the results of preferred fertilization of the low frequency of 2n male gametes with the female gametes of the cultivated sunflower, due to the dosage factors related to recognition and rejection of foreign pollen during fertilization. The triploids have been used to produce amphiploids and aneuploids. Future studies of the male gametes’ fate from pollination through fertilization will further uncover the mechanism of this whole genome transmission. Studies of the genetic control of this trait will facilitate research on sunflower polyploidy speciation and evolution, and the utilization of this trait in sunflower breeding. PMID:28179393

  17. Triploid Production from Interspecific Crosses of Two Diploid Perennial Helianthus with Diploid Cultivated Sunflower (Helianthus annuus L.).

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    Liu, Zhao; Seiler, Gerald J; Gulya, Thomas J; Feng, Jiuhuan; Rashid, Khalid Y; Cai, Xiwen; Jan, Chao-Chien

    2017-02-07

    Wild Helianthus species are a valuable genetic resource for the improvement of cultivated sunflower. We report the discovery and characterization of a unique high frequency production of triploids when cultivated sunflower was pollinated by specific accessions of diploid Helianthus nuttallii T. &. G. and H. maximiliani Schr. Genomic in situ hybridization (GISH) analyses indicated that the triploid F1s had two genomes from the wild pollen sources and one from the cultivated line. Mitotic chromosome analyses indicated that the frequency of triploid progenies from the crosses of cultivated lines × H. nuttallii accession 102 (N102) was significantly higher than those of unexpected polyploid progenies from the crosses of wild perennial species × N102, and no unexpected polyploids were obtained from the reverse crosses. Pollen stainability analysis suggested the existence of a low percentage of unreduced (2n) male gametes in some accessions, especially N102 and H. maximiliani accession 1113 (M1113), which were generated at the telophase II and tetrad stages of meiosis. The triploid F1s could be the results of preferred fertilization of the low frequency of 2n male gametes with the female gametes of the cultivated sunflower, due to the dosage factors related to recognition and rejection of foreign pollen during fertilization. The triploids have been used to produce amphiploids and aneuploids. Future studies of the male gametes' fate from pollination through fertilization will further uncover the mechanism of this whole genome transmission. Studies of the genetic control of this trait will facilitate research on sunflower polyploidy speciation and evolution, and the utilization of this trait in sunflower breeding.

  18. Hybridization as a facilitator of species range expansion

    Science.gov (United States)

    2016-01-01

    Explaining the evolution of species geographical ranges is fundamental to understanding how biodiversity is distributed and maintained. The solution to this classic problem in ecology and evolution remains elusive: we still do not fully know how species geographical ranges evolve and what factors fuel range expansions. Resolving this problem is now more crucial than ever with increasing biodiversity loss, global change and movement of species by humans. Here, we describe and evaluate the hypothesis that hybridization between species can contribute to species range expansion. We discuss how such a process can occur and the empirical data that are needed to test this hypothesis. We also examine how species can expand into new environments via hybridization with a resident species, and yet remain distinct species. Generally, hybridization may play an underappreciated role in influencing the evolution of species ranges. Whether—and to what extent—hybridization has such an effect requires further study across more diverse taxa. PMID:27683368

  19. Resolving incongruence: Species of hybrid origin in Columnea (Gesneriaceae).

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    Smith, James F; Clark, John L; Amaya-Márquez, Marisol; Marín-Gómez, Oscar H

    2017-01-01

    Speciation by hybridization has long been recognized among plants and includes both homoploid and allopolyploid speciation. The numbers of presumed hybrid species averages close to 11% and tends to be concentrated in a subset of angiosperm families. Recent advances in molecular methods have verified species of hybrid origin that had been presumed on the basis of morphology and have identified species that were not initially considered hybrids. Identifying species of hybrid origin is often a challenge and typically based on intermediate morphology, or discrepancies between molecular datasets. Discrepancies between data partitions may result from several factors including poor support, incomplete lineage sorting, or hybridization. A phylogenetic analysis of species in Columnea (Gesneriaceae) indicated significant incongruencies between the cpDNA and nrDNA datasets. Tests that examined whether one or both of the datasets had the phylogenetic signal to reject the topology of the alternate dataset (Shimodaira and Hasegawa [SH] and approximately unbiased [AU] tests) indicated significant differences between the topologies. Splitstree analyses also showed that there was support for the placement of the discrepant taxa in both datasets and that the combined data placed the putative hybrid species in an intermediate position between the two datasets. The genealogical sorting index (GSI) implied that coalescence in nrDNA had occurred in all species where more than a single individual had been sampled, but the GSI value was lower for the cpDNA of most of the putative hybrids, implying that these regions have not yet coalesced in these lineages despite being haploid. The JML test that evaluates simulated species pairwise distances against observed distances also implies that observed nrDNA data generate shorter distances than simulated data, implying hybridization. It is most likely that C. gigantifolia, C. rubriacuta, and C. sp. nov. represent a lineage from a hybrid ancestor

  20. Double fertilization in Helianthus

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    J. Telżyńska

    2015-01-01

    Full Text Available After controlled pollination of Helianthus annuus L. florets, the whole course of fertilization is described and documented on 24 microphotos. The timing of events is evaluated. The average cell cycle in the proembryo is 2 hours and the nuclear cycle in endosperm - 60 minutes.Plasmoptysis is suggested as the mechanism of pollen tube opening in the synergid. The structure of the thread-like sperm nucleus is interpreted as an end to end union of chromosomes, and the morphological changes of the sperm nuclei are explained as folding and coiling, based on a spiralization mechanism of chromosomes. Cytochemical observations indicating ribosome formation in the course of the nuclear cycles in the endosperm are described. The mechanisms accelerating nuclear cycles in the endosperm are discussed.

  1. Natural hybridization and introgression in sympatric Ligularia species (Asteraceae, Senecioneae)

    Institute of Scientific and Technical Information of China (English)

    Jiao-Jun YU; Chiaki KURODA; Xun GONG

    2011-01-01

    The difficulty in clarifying species of genus Ligularia Cass.has been attributed to rapid and continuous allopatric speciation in small and isolated populations,combined with interspecific diploid hybridization in the Qinghai-Tibetan Plateau and adjacent areas.However,no concrete example has been reported to prove this hypothesis.We studied a natural mixed population of six species of Ligularia in which some individuals were morphologically intermediate between L.subspicata and L.nelumbifolia.Based on DNA sequences (trnC-E trnL-rpL32,trnQ5'rpsl6,trnK-rpsl6,and internal transcribed spacer) and inter-simple sequence repeat data,we concluded that putative hybrids are primarily products of hybridization between L.nelumbifolia and L.subspicata.The other four species or additional,unknown species may also be involved in hybridization.This hybridization is bidirectional but asymmetrical.Hybrid individuals were mostly the first generation,but F2 and later-generation hybrids were also present.Moreover,the backcrossed individuals detected indicate that natural gene flow occurs among at least three Ligularia species.Hybrids may become stabilized to form new species or may function as intermediates in evolutionary diversification.

  2. Hybrid Viability and Fertility in Co-occuring Plant Species

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    Hernandez, E.; Garcia, C.; Yost, J.

    2012-12-01

    Similar species of plants can co-exist due to reproductive barriers that keep them from hybridizing. In the case of Lasthenia gracilis and L. californica, certain reproductive barriers allow them to co-exist at Jasper Ridge without hybridization. The two species are locally adapted to different regions of the same hillside, and have slight differences in flowering time but hybrids can be created at low rate in the green house. We tested the viability and fertility of green house produced hybrids to quantify post-zygotic reproductive isolation at Jasper Ridge. We planted 10 hybrid seeds and 10 control seeds from 11 different families. We measured the percent germination, survival to flowering and pollen fertility of the seeds. We expect lower germination, lower survival to flowering, and lower pollen viability of hybrid seeds as compared to control seeds.

  3. DEVELOPMENT OF CODOMINANT MARKERS FOR IDENTIFYING SPECIES HYBRIDS

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    Herein we describe a simple method for developing species-diagnostic markers that would permit the rapid identification of hybrid individuals. Our method relies on amplified length polymorphism (AFLP) and single strand conformation polymorphism (SSCP) technologies, both of which...

  4. Interpretation of the biological species concept from interspecific hybridization of two Helicoverpa species

    Institute of Scientific and Technical Information of China (English)

    WANG ChenZhu

    2007-01-01

    The biological species concept defines species in terms of interbreeding. Interbreeding between species is prevented by reproductive isolation mechanisms. Based on our results of interspecific hybridization between Helicoverpa armigera and Helicoverpa assulta, reproductive isolation mechanisms of the two species are analyzed. A combination of prezygotic factors (absent sex attraction and physical incompatibility of the genitalia) and postzygotic factors (female absence and partial sterility in F1 hybrids) causes reproductive isolation of the two species. In addition, the role of interspecific hybridization in speciation is discussed.

  5. Hybrid dynamics in a species group of swallowtail butterflies.

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    Dupuis, J R; Sperling, F A H

    2016-10-01

    Hybrid zones provide unique natural laboratories for studying mechanisms of evolution. But identification and classification of hybrid individuals (F1, F2, backcross, etc.) can be complicated by real population changes over time as well as by use of different marker types, both of which challenge documentation of hybrid dynamics. Here, we use multiple genetic markers (mitochondrial DNA, microsatellites and genomewide single nucleotide polymorphisms) to re-examine population structure in a hybrid zone between two species of swallowtail butterflies in western Canada, Papilio machaon and P. zelicaon. Our aim was to test whether their hybrid dynamics remain the same as found 30 years ago using morphology and allozymes, and we compared different genetic data sets as well as alternative hybrid identification and classification methods. Overall, we found high differentiation between the two parental species, corroborating previous research from the 1980s. We identified fewer hybrid individuals in the main zone of hybridization in recent years, but this finding depended on the genetic markers considered. Comparison of methods with simulated data sets generated from our data showed that single nucleotide polymorphisms were more powerful than microsatellites for both hybrid identification and classification. Moreover, substantial variation among comparisons underlined the value of multiple markers and methods for documenting evolutionarily dynamic systems.

  6. Cytogenetics of intergeneric hybrids between Brassica species and Orychophragmus violaceus

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In the sexual intergeneric hybrids between the cultivated Brassica species and Orychophragmus violaceus, both complete separation and partial separation of the parental genomes were found to occur during mitosis and meiosis under genetic control. The cytogenetics of these hybrids was species-specific for Brassica parents. The different chromosome behavior of hybrids with three Brassica diploids ( B. campestris , B. nigra and B. oleracea ) might contribute to the different cytogenetics of hybrids with three tetraploids ( B. napus, B. juncea and B. carinata). Owing to the parental genome separation, Brassica homozygous plants and aneuploids with various chromosome constitutions were identifiable in the progenies of these hybrids, which were valuable for the study of the structure and evolution of Brassica genome and for the breeding of Brassica crops.

  7. Hybridization and endangered species protection in the molecular era.

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    Wayne, Robert K; Shaffer, H Bradley

    2016-06-01

    After decades of discussion, there is little consensus on the extent to which hybrids between endangered and nonendangered species should be protected by US law. As increasingly larger, genome-scale data sets are developed, we can identify individuals and populations with even trace levels of genetic admixture, making the 'hybrid problem' all the more difficult. We developed a decision-tree framework for evaluating hybrid protection, including both the processes that produced hybrids (human-mediated or natural) and the ecological impact of hybrids on natural ecosystems. We then evaluated our decision tree for four case studies drawn from our own work and briefly discuss several other cases from the literature. Throughout, we highlight the management outcomes that our approach provides and the nuances of hybridization as a conservation problem.

  8. Interspecific differentiation and hybridization in vanilla species (Orchidaceae)

    DEFF Research Database (Denmark)

    Nielsen, Lene Rostgaard; Siegismund

    1999-01-01

    that the genetic composition of the three species is also very similar: they deviate mainly from each other in allele frequencies rather than by specific alleles. A hierarchical analysis of genetic differentiation showed that the between-species component is slightly higher (FSG=0.237) than the component between...... populations within species (FPS=0.141). Nevertheless, they are efficiently recognized by their genotypic compositions. In V. barbellata and V. claviculata 97-99% of all individuals were assigned to the correct species. Assignment to a wrong species occurred only with individuals at localities where species...... coexist. This suggests that the species may hybridize....

  9. Epigenetic Programming:The Challenge to Species Hybridization

    Institute of Scientific and Technical Information of China (English)

    Ryo lshikawa; Tetsu Kinoshita

    2009-01-01

    In many organisms,the genomes of individual species are isolated by a range of reproductive barriers that act before or after fertilization.Successful mating between species results in the presence of different genomes within a cell (hybridization),which can lead to incompatibility in cellular events due to adverse genetic interactions.In addition to such genetic interactions,recent studies have shown that the epigenetic control of the genome,silencing of transposons,control of non-additive gene expression and genomic imprinting might also contribute to reproductive barriers in plant and animal species.These genetic and epigenetic mechanisms play a significant role in the prevention of gene flow between species.In this review,we focus on aspects of epigenetic control related to hybrid incompatibility during species hybridization,and also consider key mechanism(s) in the interaction between different genomes.

  10. Reproductive characterization of interspecific hybrids among Capsicum species

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo da Silva Monteiro

    2011-01-01

    Full Text Available The objective of this study was the reproductive characterization of Capsicum accessions as well as of interspecifichybrids, based on pollen viability. Hybrids were obtained between Capsicum species. Pollen viability was high in most accessions,indicating that meiosis is normal, resulting in viable pollen grains. The pollen viability of species C. pubescens was the lowest (27%. The interspecific hybrids had varying degrees of pollen viability, from fertile combinations (C. chinense x C. frutescens and C.annuum x C. baccatum to male sterile combinations. Pollen viability also varied within the hybrid combination according toaccessions used in the cross. Results indicate that male sterility is one of the incompatibility barriers among Capsicum species sincehybrids can be established, but may be male sterile.

  11. Ecogeography and utility to plant breeding of the crop wild relatives of sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Kantar, Michael B; Sosa, Chrystian C; Khoury, Colin K; Castañeda-Álvarez, Nora P; Achicanoy, Harold A; Bernau, Vivian; Kane, Nolan C; Marek, Laura; Seiler, Gerald; Rieseberg, Loren H

    2015-01-01

    Crop wild relatives (CWR) are a rich source of genetic diversity for crop improvement. Combining ecogeographic and phylogenetic techniques can inform both conservation and breeding. Geographic occurrence, bioclimatic, and biophysical data were used to predict species distributions, range overlap and niche occupancy in 36 taxa closely related to sunflower (Helianthus annuus L.). Taxa lacking comprehensive ex situ conservation were identified. The predicted distributions for 36 Helianthus taxa identified substantial range overlap, range asymmetry and niche conservatism. Specific taxa (e.g., Helianthus deblis Nutt., Helianthus anomalus Blake, and Helianthus divaricatus L.) were identified as targets for traits of interest, particularly for abiotic stress tolerance, and adaptation to extreme soil properties. The combination of techniques demonstrates the potential for publicly available ecogeographic and phylogenetic data to facilitate the identification of possible sources of abiotic stress traits for plant breeding programs. Much of the primary genepool (wild H. annuus) occurs in extreme environments indicating that introgression of targeted traits may be relatively straightforward. Sister taxa in Helianthus have greater range overlap than more distantly related taxa within the genus. This adds to a growing body of literature suggesting that in plants (unlike some animal groups), geographic isolation may not be necessary for speciation.

  12. Ecogeography and utility to plant breeding of the crop wild relatives of sunflower (Helianthus annuus L.

    Directory of Open Access Journals (Sweden)

    Michael Benjamin Kantar

    2015-10-01

    Full Text Available Crop wild relatives (CWR are a rich source of genetic diversity for crop improvement. Combining ecogeographic and phylogenetic techniques can inform both conservation and breeding. Geographic occurrence, bioclimatic, and biophysical data were used to predict species distributions, range overlap and niche occupancy in 36 taxa closely related to sunflower (Helianthus annuus L.. Taxa lacking comprehensive ex situ conservation were identified. The predicted distributions for 36 Helianthus taxa identified substantial range overlap and asymmetry and niche conservatism. Specific taxa (e.g., Helianthus deblis Nutt., Helianthus anomalus Blake, and Helianthus divaricatus L. were identified as targets for traits of interest, particularly for abiotic stress tolerance and adaptation to extreme soil properties. The combination of techniques demonstrates the potential for publicly available ecogeographic and phylogenetic data to facilitate the identification of possible sources of abiotic stress traits for plant breeding programs. Much of the primary genepool (wild H. annuus occurs in extreme environments indicating that introgression of targeted traits may be relatively straightforward. Sister taxa in Helianthus have greater range overlap than more distantly related taxa within the genus. This adds to a growing body of literature suggesting that in plants (unlike some animal groups, geographic isolation may not be necessary for speciation.

  13. Fish predation on a Daphnia hybrid species complex: A factor explaining species coexistence?

    NARCIS (Netherlands)

    Spaak, P.; Hoekstra, J.F.

    1997-01-01

    Recent studies on the life histories of Daphnia hybrids and their parental species have revealed that hybrids can combine an intermediate size with a relatively high reproductive rate, which might explain their success in many European lakes. Based on this information, we formulated the temporal

  14. Gene Transfer & Hybridization Studies in Hyperthermophilic Species

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Karen E.

    2005-10-14

    A. ABSTRACT The importance of lateral gene transfer (LGT) in the evolution of microbial species has become increasingly evident with each completed microbial genome sequence. Most significantly, the genome of Thermotoga maritima MSB8, a hyperthermophilic bacterium isolated by Karl Stetter and workers from Vulcano Italy in 1986, and sequenced at The Institute for Genomic Research (TIGR) in Rockville Maryland in 1999, revealed extensive LGT between % . this bacterium and members of the archaeal domain (in particular Archaeoglobus fulgidus, and Pyracoccus frcriosus species). Based on whole genome comparisons, it was estimated that 24% of the genetic information in this organism was acquired by genetic exchange with archaeal species, Independent analyses including periodicity analysis of the T. maritimu genomic DNA sequence, phylogenetic reconstruction based on genes that appear archaeal-like, and codon and amino acid usage, have provided additional evidence for LGT between T. maritima and the archaea. More recently, DiRuggiero and workers have identified a very recent LGT event between two genera of hyperthermophilic archaea, where a nearly identical DNA fragment of 16 kb in length flanked by insertion sequence (IS) elements, exists. Undoubtedly, additional examples of LGT will be identified as more microbial genomes are completed. For the present moment however, the genome sequence of T. maritima and other hyperthermophiles including P. furiosus, Pyrococcus horikoshii, Pyrococcus abyssi, A. fulgidus, and Aquifex aeolicus, have significantly increased out awareness of evolution being a web of life rather than a tree of life, as suggested by single gene phylogenies. In this proposal, we will aim to determine the extent of LGT across the hyperthemophiles, employing iY maritima as the model organism. A variety of biochemical techniques and phylogenetic reconstructions will allow for a detailed and thorough characterization of the extent of LGT in this species. The

  15. Analysis of nuclear and organellar DNA in somatic hybrids between solanaceous species.

    NARCIS (Netherlands)

    Wolters, A.M.A.

    1994-01-01

    This thesis describes an analysis of the possibilities and limitations of somatic hybridization of solanaceous species. Emphasis was laid on the elucidation of the interactions between nuclei, chloroplasts and mitochondria in the obtained somatic hybrids. Hybridization experiments between tomato ( L

  16. Genetics of hybrid male sterility among strains and species in the Drosophila pseudoobscura species group.

    Science.gov (United States)

    McDermott, Shannon R; Noor, Mohamed A F

    2011-07-01

    Taxa in the early stages of speciation may bear intraspecific allelic variation at loci conferring barrier traits in hybrids such as hybrid sterility. Additionally, hybridization may spread alleles that confer barrier traits to other taxa. Historically, few studies examine within- and between-species variation at loci conferring reproductive isolation. Here, we test for allelic variation within Drosophila persimilis and within the Bogota subspecies of D. pseudoobscura at regions previously shown to contribute to hybrid male sterility. We also test whether D. persimilis and the USA subspecies of D. pseudoobscura share an allele conferring hybrid sterility in a D. pseudoobscura bogotana genetic background. All loci conferred similar hybrid sterility effects across all strains studied, although we detected some statistically significant quantitative effect variation among D. persimilis alleles of some hybrid incompatibility QTLs. We also detected allelism between D. persimilis and D. pseudoobscura USA at a second chromosome hybrid sterility QTL. We hypothesize that either the QTL is ancestral in D. persimilis and D. pseudoobscura USA and lost in D. pseudoobscura bogotana, or gene flow transferred the QTL from D. persimilis to D. pseudoobscura USA. We discuss our findings in the context of population features that may contribute to variation in hybrid incompatibilities.

  17. Evaluation of rare Helianthus eggertii achenes for oil concentration and fatty acid composition

    Science.gov (United States)

    Sunflower (Helianthus annuus L.) oil has the potential to be improved for nutritional and industrial purposes through selection and breeding. The narrow genetic base of cultivated sunflower has been broadened by the infusion of genes from wild species, resulting in a continuous improvement in agrono...

  18. Effect of wild Helianthus cytoplasms on agronomic and oil characteristics of cultivated sunflower (H. annuus L.)

    Science.gov (United States)

    Sunflower (Helianthus annuus L.) productions reliance on a single source of cytoplasmic male-sterility, PET1, derived from H. petiolaris Nutt., makes the crop genetically vulnerable. Twenty diverse cytoplasmic substitution lines from annual and perennial wild species were compared with the inbred li...

  19. Identification of molecular markers linked to a new nuclear male-sterility gene ms7 in sunflower (Helianthus annuus L.)

    Science.gov (United States)

    Nuclear male sterility (NMS) is an important alternative system to the cytoplasm male sterility (CMS) in hybrid breeding programs because of its stable male sterility and abundant available restorer resources. For sunflower (Helianthus annuus L.), NMS 89-552, a nuclear male-sterile mutant induced by...

  20. Introgressive hybridization of Schistosoma haematobium group species in Senegal: species barrier break down between ruminant and human schistosomes.

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    Bonnie L Webster

    Full Text Available BACKGROUND: Schistosomes are dioecious parasitic flatworms, which live in the vasculature of their mammalian definitive hosts. They are the causative agent of schistosomiasis, a disease of considerable medical and veterinary importance in tropical and subtropical regions. Schistosomes undergo a sexual reproductive stage within their mammalian host enabling interactions between different species, which may result in hybridization if the species involved are phylogenetically close. In Senegal, three closely related species in the Schistosoma haematobium group are endemic: S. haematobium, which causes urogenital schistosomiasis in humans, and S. bovis and S. curassoni, which cause intestinal schistosomiasis in cows, sheep and goats. METHODOLOGY/PRINCIPAL FINDINGS: Large-scale multi-loci molecular analysis of parasite samples collected from children and domestic livestock across Senegal revealed that interactions and hybridization were taking place between all three species. Evidence of hybridization between S. haematobium/S. curassoni and S. haematobium/S. bovis was commonly found in children from across Senegal, with 88% of the children surveyed in areas of suspected species overlap excreting hybrid miracidia. No S. haematobium worms or hybrids thereof were found in ruminants, although S. bovis and S. curassoni hybrid worms were found in cows. Complementary experimental mixed species infections in laboratory rodents confirmed that males and females of each species readily pair and produce viable hybrid offspring. CONCLUSIONS/SIGNIFICANCE: THESE DATA PROVIDE INDISPUTABLE EVIDENCE FOR: the high occurrence of bidirectional hybridization between these Schistosoma species; the first conclusive evidence for the natural hybridisation between S. haematobium and S. curassoni; and demonstrate that the transmission of the different species and their hybrids appears focal. Hybridization between schistosomes has been known to influence the disease epidemiology

  1. Widespread hybridization among species of Indian major carps in hatcheries, but not in the wild

    DEFF Research Database (Denmark)

    Simonsen, V.; Hansen, Michael Møller; Mensberg, Karen-Lise Dons;

    2005-01-01

    samples. Individual admixture coefficients showed that 24% of all hatchery-reared fishes were hybrids, whereas a single hybrid was observed in the wild-caught samples. Only catla Catla catla x rohu Labeo rohita and mrigal Cirrhinus cirrhosus x rohu hybrids were observed, the vast majority of which were F......-hybrids in hatchery samples, reproductive barriers among species have so far precluded widespread introgression. Continued hybridization may eventually lead to a breakdown of species barriers, thereby compromising the genetic integrity of the species in the wild, and leading to production losses...

  2. [DNA-DNA hybridization in several species of Hansenula].

    Science.gov (United States)

    Poncet, S; Fiol, J B; Billon-Grand, G

    1984-05-30

    The genus Hansenula was considered a long time ago as a good pattern for phylogenetic research. In 1969, Wickerham proposed an evolutive scheme based upon morphological, physiological and ecological criteria. Recently, relatedness among yeasts were analysed by DNA-DNA hybridization in liquid medium. H. anomala var. anomala (G + C content: 37.1%) was compared with H. anomala var. schneggii (37.6%), H. subpelliculosa (33.8%) line 3, H. sydowiorum (40.1%) and H. muscicola (37.1%). These results showed little relatedness between H. anomala var. anomala/H. ciferrii and H. anomala var. anomala/H. subpelliculosa. On the other hand, H. anomala var. schneggii shared 89.5% of its nucleotide sequences with H. anomala var. anomala. These 2 strains were considered to represent the same species. H. holstii showed 67.1% complementarity with H. anomala var. anomala: this strain is considered to represent valid species, different from H. anomala var. anomala, but H. muscicola with 72.5% relatedness to H. anomala var. anomala could be considered as a 'limit species'. An unexpected finding was that H. beckii was closely related to H. anomala var. anomala (84.8%). These data suggested the inadequacy of current criteria used to establish the phylogenetic lines in genus Hansenula.

  3. Hybridization between alien species Rumex obtusifolius and closely related native vulnerable species R. longifolius in a mountain tourist destination

    Science.gov (United States)

    Takahashi, Koichi; Hanyu, Masaaki

    2015-01-01

    Alien species expand their distribution by transportation network development. Hybridization between alien species Rumex obtusifolius and closely related native vulnerable species R. longifolius was examined in a mountain tourist destination in central Japan. The three taxa were morphologically identified in the field. Stem height and leaf area were greater in R. longifolius than R. obtusifolius; hybrids were intermediate between the two Rumex species. R. longifolius and the hybrids grew mainly in wet land and the river tributary; R. obtusifolius grew mainly at the roadside and in meadows. Hybrid germination rates of pollen and seeds were much lower than for the two Rumex species. Clustering analysis showed the three taxa each formed a cluster. Most hybrids were F1 generation; the possibility was low of introgression into the two Rumex species by backcross. This study clarified that (1) hybridization occurred between R. obtusifolius and R. longifolius because they occurred together in a small area, but grew in different water habitat conditions, and (2) hybridization was mostly F1 generation because hybrid pollen and seed fertility was low. However, we need caution about introgression into R. longifolius by R. obtusifolius in this area because of the slight possibility of F2 generation and backcrosses. PMID:26354180

  4. Hybridization between alien species Rumex obtusifolius and closely related native vulnerable species R. longifolius in a mountain tourist destination.

    Science.gov (United States)

    Takahashi, Koichi; Hanyu, Masaaki

    2015-09-10

    Alien species expand their distribution by transportation network development. Hybridization between alien species Rumex obtusifolius and closely related native vulnerable species R. longifolius was examined in a mountain tourist destination in central Japan. The three taxa were morphologically identified in the field. Stem height and leaf area were greater in R. longifolius than R. obtusifolius; hybrids were intermediate between the two Rumex species. R. longifolius and the hybrids grew mainly in wet land and the river tributary; R. obtusifolius grew mainly at the roadside and in meadows. Hybrid germination rates of pollen and seeds were much lower than for the two Rumex species. Clustering analysis showed the three taxa each formed a cluster. Most hybrids were F1 generation; the possibility was low of introgression into the two Rumex species by backcross. This study clarified that (1) hybridization occurred between R. obtusifolius and R. longifolius because they occurred together in a small area, but grew in different water habitat conditions, and (2) hybridization was mostly F1 generation because hybrid pollen and seed fertility was low. However, we need caution about introgression into R. longifolius by R. obtusifolius in this area because of the slight possibility of F2 generation and backcrosses.

  5. Hybridization may facilitate in situ survival of endemic species through periods of climate change

    Science.gov (United States)

    Becker, Matthias; Gruenheit, Nicole; Steel, Mike; Voelckel, Claudia; Deusch, Oliver; Heenan, Peter B.; McLenachan, Patricia A.; Kardailsky, Olga; Leigh, Jessica W.; Lockhart, Peter J.

    2013-12-01

    Predicting survival and extinction scenarios for climate change requires an understanding of the present day ecological characteristics of species and future available habitats, but also the adaptive potential of species to cope with environmental change. Hybridization is one mechanism that could facilitate this. Here we report statistical evidence that the transfer of genetic information through hybridization is a feature of species from the plant genus Pachycladon that survived the Last Glacial Maximum in geographically separated alpine refugia in New Zealand's South Island. We show that transferred glucosinolate hydrolysis genes also exhibit evidence of intra-locus recombination. Such gene exchange and recombination has the potential to alter the chemical defence in the offspring of hybridizing species. We use a mathematical model to show that when hybridization increases the adaptive potential of species, future biodiversity will be best protected by preserving closely related species that hybridize rather than by conserving distantly related species that are genetically isolated.

  6. Hybrid female mate choice as a species isolating mechanism: environment matters.

    Science.gov (United States)

    Schmidt, E M; Pfennig, K S

    2016-04-01

    A fundamental goal of biology is to understand how new species arise and are maintained. Female mate choice is potentially critical to the speciation process: mate choice can prevent hybridization and thereby generate reproductive isolation between potentially interbreeding groups. Yet, in systems where hybridization occurs, mate choice by hybrid females might also play a key role in reproductive isolation by affecting hybrid fitness and contributing to patterns of gene flow between species. We evaluated whether hybrid mate choice behaviour could serve as such an isolating mechanism using spadefoot toad hybrids of Spea multiplicata and Spea bombifrons. We assessed the mate preferences of female hybrid spadefoot toads for sterile hybrid males vs. pure-species males in two alternative habitat types in which spadefoots breed: deep or shallow water. We found that, in deep water, hybrid females preferred the calls of sterile hybrid males to those of S. multiplicata males. Thus, maladaptive hybrid mate preferences could serve as an isolating mechanism. However, in shallow water, the preference for hybrid male calls was not expressed. Moreover, hybrid females did not prefer hybrid calls to those of S. bombifrons in either environment. Because hybrid female mate choice was context-dependent, its efficacy as a reproductive isolating mechanism will depend on both the environment in which females choose their mates as well as the relative frequencies of males in a given population. Thus, reproductive isolation between species, as well as habitat specific patterns of gene flow between species, might depend critically on the nature of hybrid mate preferences and the way in which they vary across environments.

  7. Hybrid incompatibility is acquired faster in annual than in perennial species of sunflower and tarweed.

    Science.gov (United States)

    Owens, Gregory L; Rieseberg, Loren H

    2014-03-01

    Hybrid sterility is an important species barrier, especially in plants where hybrids can often form between divergent taxa. Here we explore how life history affects the acquisition of hybrid sterility in two groups in the sunflower family. We analyzed genetic distance and F1 pollen sterility for interspecific crosses in annual and perennial groups. We find that reproductive isolation is acquired in a steady manner and that annual species acquire hybrid sterility barriers faster than perennial species. Potential causes of the observed sterility pattern are discussed.

  8. Multifaceted, cross-generational costs of hybridization in sibling Drosophila species.

    Directory of Open Access Journals (Sweden)

    Erin M Myers

    Full Text Available Maladaptive hybridization, as determined by the pattern and intensity of selection against hybrid individuals, is an important factor contributing to the evolution of prezygotic reproductive isolation. To identify the consequences of hybridization between Drosophila pseudoobscura and D. persimilis, we estimated multiple fitness components for F1 hybrids and backcross progeny and used these to compare the relative fitness of parental species and their hybrids across two generations. We document many sources of intrinsic (developmental and extrinsic (ecological selection that dramatically increase the fitness costs of hybridization beyond the well-documented F1 male sterility in this model system. Our results indicate that the cost of hybridization accrues over multiple generations and reinforcement in this system is driven by selection against hybridization above and beyond the cost of hybrid male sterility; we estimate a fitness loss of >95% relative to the parental species across two generations of hybridization. Our findings demonstrate the importance of estimating hybridization costs using multiple fitness measures from multiple generations in an ecologically relevant context; so doing can reveal intense postzygotic selection against hybridization and thus, an enhanced role for reinforcement in the evolution of populations and diversification of species.

  9. Human disturbance causes the formation of a hybrid swarm between two naturally sympatric fish species.

    Science.gov (United States)

    Hasselman, Daniel J; Argo, Emily E; McBride, Meghan C; Bentzen, Paul; Schultz, Thomas F; Perez-Umphrey, Anna A; Palkovacs, Eric P

    2014-03-01

    Most evidence for hybrid swarm formation stemming from anthropogenic habitat disturbance comes from the breakdown of reproductive isolation between incipient species, or introgression between allopatric species following secondary contact. Human impacts on hybridization between divergent species that naturally occur in sympatry have received considerably less attention. Theory predicts that reinforcement should act to preserve reproductive isolation under such circumstances, potentially making reproductive barriers resistant to human habitat alteration. Using 15 microsatellites, we examined hybridization between sympatric populations of alewife (Alosa pseudoharengus) and blueback herring (A. aestivalis) to test whether the frequency of hybridization and pattern of introgression have been impacted by the construction of a dam that isolated formerly anadromous populations of both species in a landlocked freshwater reservoir. The frequency of hybridization and pattern of introgression differed markedly between anadromous and landlocked populations. The rangewide frequency of hybridization among anadromous populations was generally 0-8%, whereas all landlocked individuals were hybrids. Although neutral introgression was observed among anadromous hybrids, directional introgression leading to increased prevalence of alewife genotypes was detected among landlocked hybrids. We demonstrate that habitat alteration can lead to hybrid swarm formation between divergent species that naturally occur sympatrically, and provide empirical evidence that reinforcement does not always sustain reproductive isolation under such circumstances.

  10. Reconstructing the history of selection during homoploid hybrid speciation.

    Science.gov (United States)

    Karrenberg, Sophie; Lexer, Christian; Rieseberg, Loren H

    2007-06-01

    This study aims to identify selection pressures during the historical process of homoploid hybrid speciation in three Helianthus (sunflower) hybrid species. If selection against intrinsic genetic incompatibilities (fertility selection) or for important morphological/ecological traits (phenotypic selection) were important in hybrid speciation, we would expect this selection to have influenced the parentage of molecular markers or chromosomal segments in the hybrid species' genomes. To infer past selection, we compared the parentage of molecular markers in high-density maps of the three hybrid species with predicted marker parentage from an analysis of fertility selection in artificial hybrids and from the directions of quantitative trait loci effects with respect to the phenotypes of the hybrid species. Multiple logistic regression models were consistent with both fertility and phenotypic selection in all three species. To further investigate traits under selection, we used a permutation test to determine whether marker parentage predicted from groups of functionally related traits differed from neutral expectations. Our results suggest that trait groups associated with ecological divergence were under selection during hybrid speciation. This study presents a new method to test for selection and supports earlier claims that fertility selection and phenotypic selection on ecologically relevant traits have operated simultaneously during sunflower hybrid speciation.

  11. Naturally occurring hybrids of coral reef butterflyfishes have similar fitness compared to parental species

    Science.gov (United States)

    Hobbs, Jean-Paul A.; Pratchett, Morgan S.; Bay, Line K.; van Herwerden, Lynne

    2017-01-01

    Hybridisation can produce evolutionary novelty by increasing fitness and adaptive capacity. Heterosis, or hybrid vigour, has been documented in many plant and animal taxa, and is a notable consequence of hybridisation that has been exploited for decades in agriculture and aquaculture. On the contrary, loss of fitness in naturally occurring hybrid taxa has been observed in many cases. This can have negative consequences for the parental species involved (wasted reproductive effort), and has raised concerns for species conservation. This study evaluates the relative fitness of previously documented butterflyfish hybrids of the genus Chaetodon from the Indo-Pacific suture zone at Christmas Island. Histological examination confirmed the reproductive viability of Chaetodon hybrids. Examination of liver lipid content showed that hybrid body condition was not significantly different from parent species body condition. Lastly, size at age data revealed no difference in growth rates and asymptotic length between hybrids and parent species. Based on the traits measured in this study, naturally occurring hybrids of Chaetodon butterflyfishes have similar fitness to their parental species, and are unlikely to supplant parental species under current environmental conditions at the suture zone. However, given sufficient fitness and ongoing genetic exchange between the respective parental species, hybrids are likely to persist within the suture zone. PMID:28257492

  12. Natural hybridization in heliconiine butterflies: the species boundary as a continuum

    Directory of Open Access Journals (Sweden)

    Beltrán Margarita

    2007-02-01

    Full Text Available Abstract Background To understand speciation and the maintenance of taxa as separate entities, we need information about natural hybridization and gene flow among species. Results Interspecific hybrids occur regularly in Heliconius and Eueides (Lepidoptera: Nymphalidae in the wild: 26–29% of the species of Heliconiina are involved, depending on species concept employed. Hybridization is, however, rare on a per-individual basis. For one well-studied case of species hybridizing in parapatric contact (Heliconius erato and H. himera, phenotypically detectable hybrids form around 10% of the population, but for species in sympatry hybrids usually form less than 0.05% of individuals. There is a roughly exponential decline with genetic distance in the numbers of natural hybrids in collections, both between and within species, suggesting a simple "exponential failure law" of compatibility as found in some prokaryotes. Conclusion Hybridization between species of Heliconius appears to be a natural phenomenon; there is no evidence that it has been enhanced by recent human habitat disturbance. In some well-studied cases, backcrossing occurs in the field and fertile backcrosses have been verified in insectaries, which indicates that introgression is likely, and recent molecular work shows that alleles at some but not all loci are exchanged between pairs of sympatric, hybridizing species. Molecular clock dating suggests that gene exchange may continue for more than 3 million years after speciation. In addition, one species, H. heurippa, appears to have formed as a result of hybrid speciation. Introgression may often contribute to adaptive evolution as well as sometimes to speciation itself, via hybrid speciation. Geographic races and species that coexist in sympatry therefore form part of a continuum in terms of hybridization rates or probability of gene flow. This finding concurs with the view that processes leading to speciation are continuous, rather than

  13. Importance of hybridization between indigenous and nonindigenous freshwater species: an overlooked threat to North American biodiversity.

    Science.gov (United States)

    Perry, William L; Lodge, David M; Feder, Jeffrey L

    2002-04-01

    Biodiversity of North American freshwaters is among the greatest in the world. However, due to extensive habitat degradation, pollution, and introductions of nonindigenous species, this biodiversity is also among the most endangered. Unlike habitat degradation and pollution, nonindigenous species represent a permanent loss of biodiversity because their removal or control is often impossible. Most species introduced into nonnative North American ranges, however, are not from Eurasia but have been introduced from geographically isolated regions within North America. Although the ecological effects of introduced species have been widely documented, the effects of hybridization, especially between closely related species, represents an equally serious mechanism of extinction but is much less studied. Identification of which species are likely to hybridize after contact is of critical importance to prevent the further loss of native species. Molecular phylogenetics serves as a powerful tool to identify freshwater species at risk of introgression, if we can assume that genetic distance is a good predictor of the potential for hybridization. Although not a thorough review of all cases of hybridization, this article documents the extent and effects of hybridization in fishes, crayfishes, mussels, and other invertebrates in light of the currently accepted phylogenetic relationships. We suggest this approach may be the first step in addressing the potential threat of hybridization between many of the closely related species in North American fresh waters.

  14. Genetic basis of hybrid male sterility among three closely related species of Drosophila.

    Science.gov (United States)

    Mishra, Paras Kumar; Singh, B N

    2005-05-01

    The genetic basis of hybrid male sterility among three closely related species, Drosophila bipectinata, D. parabipectinata and D. malerkotliana has been investigated by using backcross analysis methods. The role of Y chromosome, major hybrid sterility (MHS) genes (genetic factors) and cytoplasm (non-genetic factor) have been studied in the hybrids of these three species. In the species pair, bipectinata--parabipectinata, Y chromosome introgression of parabipectinata in the genomic background of bipectinata and the reciprocal Y chromosome introgression were unsuccessful as all males in second backcross generation were sterile. Neither MHS genes nor cytoplasm was found important for sterility. This suggests the involvement of X-Y, X-autosomes or polygenic interactions in hybrid male sterility. In bipectinata--malerkotliana and parabipectinata--malerkotliana species pairs, Y chromosome substitution in reciprocal crosses did not affect male fertility. Backcross analyses also show no involvement of MHS genes or cytoplasm in hybrid male sterility in these two species pairs. Therefore, X- autosome interaction or polygenic interaction is supposed to be involved in hybrid male sterility in these two species pairs. These findings also provide evidence that even in closely related species, genetic interactions underlying hybrid male sterility may vary.

  15. Does genetic distance between parental species influence outcomes of hybridization among coral reef butterflyfishes?

    Science.gov (United States)

    Montanari, Stefano R; Hobbs, Jean-Paul A; Pratchett, Morgan S; Bay, Line K; Van Herwerden, Lynne

    2014-06-01

    Christmas Island is located at the overlap of the Indian and Pacific Ocean marine provinces and is a hot spot for marine hybridization. Here, we evaluate the ecological framework and genetic consequences of hybridization between butterflyfishes Chaetodon guttatissimus and Chaetodon punctatofasciatus. Further, we compare our current findings to those from a previous study of hybridization between Chaetodon trifasciatus and Chaetodon lunulatus. For both species groups, habitat and dietary overlap between parental species facilitate frequent heterospecific encounters. Low abundance of potential mates promotes heterospecific pair formation and the breakdown of assortative mating. Despite similarities in ecological frameworks, the population genetic signatures of hybridization differ between the species groups. Mitochondrial and nuclear data from C. guttatissimus × C. punctatofasciatus (1% divergence at cyt b) show bidirectional maternal contributions and relatively high levels of introgression, both inside and outside the Christmas Island hybrid zone. In contrast, C. trifasciatus × C. lunulatus (5% cyt b divergence) exhibit unidirectional mitochondrial inheritance and almost no introgression. Back-crossing of hybrid C. guttatissimus × C. punctatofasciatus and parental genotypes may eventually confound species-specific signals within the hybrid zone. In contrast, hybrids of C. trifasciatus and C. lunulatus may coexist with and remain genetically distinct from the parents. Our results, and comparisons with hybridization studies in other reef fish families, indicate that genetic distance between hybridizing species may be a factor influencing outcomes of hybridization in reef fish, which is consistent with predictions from terrestrially derived hybridization theory. © 2014 John Wiley & Sons Ltd.

  16. Hybridization between two cestode species and its consequences for intermediate host range

    Directory of Open Access Journals (Sweden)

    Henrich Tina

    2013-02-01

    Full Text Available Abstract Background Many parasites show an extraordinary degree of host specificity, even though a narrow range of host species reduces the likelihood of successful transmission. In this study, we evaluate the genetic basis of host specificity and transmission success of experimental F1 hybrids from two closely related tapeworm species (Schistocephalus solidus and S. pungitii, both highly specific to their respective vertebrate second intermediate hosts (three- and nine-spined sticklebacks, respectively. Methods We used an in vitro breeding system to hybridize Schistocephalus solidus and S. pungitii; hybridization rate was quantified using microsatellite markers. We measured several fitness relevant traits in pure lines of the parental parasite species as well as in their hybrids: hatching rates, infection rates in the copepod first host, and infection rates and growth in the two species of stickleback second hosts. Results We show that the parasites can hybridize in the in vitro system, although the proportion of self-fertilized offspring was higher in the heterospecific breeding pairs than in the control pure parental species. Hybrids have a lower hatching rate, but do not show any disadvantages in infection of copepods. In fish, hybrids were able to infect both stickleback species with equal frequency, whereas the pure lines were only able to infect their normal host species. Conclusions Although not yet documented in nature, our study shows that hybridization in Schistocephalus spp. is in principle possible and that, in respect to their expanded host range, the hybrids are fitter. Further studies are needed to find the reason for the maintenance of the species boundaries in wild populations.

  17. Characterization of Interspecific Hybrids Between Oryza sativa L. and Three Wild Rice Species of China by Genomic In Situ Hybridization

    Institute of Scientific and Technical Information of China (English)

    Guang-Xuan Tan; Zhi-Yong Xiong; Hua-Jun Jin; Gang Li; Li-Li Zhu; Li-Hui Shu; Guang-Cun He

    2006-01-01

    In the genus Oryza, interspecific hybrids are useful bridges for transferring the desired genes from wild species to cultivated rice (Oryza sativa L.). In the present study, hybrids between O. sativa (AA genome)and three Chinese wild rices, namely O. rufipogon (AA genome), O. officinalis (CC genome), and O. meyeriana (GG genome), were produced. Agricultural traits of the F1 hybrids surveyed were intermediate between their parents and appreciably resembled wild rice parents. Except for the O. sativa × O. rufipogon hybrid,the other F1 hybrids were completely sterile. Genomic in situ hybridization (GISH) was used for hybrid verification. Wild rice genomic DNAs were used as probes and cultivated rice DNA was used as a block. With the exception of O. rufipogon chromosomes, this method distinguished the other two wild rice and cultivated rice chromosomes at the stage of mitotic metaphase with different blocking ratios. The results suggest that a more distant phylogenetic relationship exists between O. meyeriana and O. sativa and that O. rufipogon and O. sativa share a high degree of sequence homology. The average mitotic chromosome length of O. officinalis and O. meyeriana was 1.25- and 1.51-fold that of O. sativa, respectively. 4',6'-Diamidino2-phenylindole staining showed that the chromosomes of O. officinalis and O. meyeriana harbored more heterochromatin, suggesting that the C and G genomes were amplified with repetitive sequences compared with the A genome. Although chromocenters formed by chromatln compaction were detected with wild rice-specific signals corresponding to the C and G genomes in discrete domains of the F1 hybrid interphase nuclei, the size and number of O. meyeriana chromocenters were bigger and greater than those of O. officinalis. The present results provide an important understanding of the genomic relationships and a tool for the transfer of useful genes from three native wild rice species in China to cultivars.

  18. Hybridization, agency discretion, and implementation of the U.S. Endangered Species Act.

    Science.gov (United States)

    Lind-Riehl, Jennifer F; Mayer, Audrey L; Wellstead, Adam M; Gailing, Oliver

    2016-12-01

    The U.S. Endangered Species Act (ESA) requires that the "best available scientific and commercial data" be used to protect imperiled species from extinction and preserve biodiversity. However, it does not provide specific guidance on how to apply this mandate. Scientific data can be uncertain and controversial, particularly regarding species delineation and hybridization issues. The U.S. Fish and Wildlife Service (FWS) had an evolving hybrid policy to guide protection decisions for individuals of hybrid origin. Currently, this policy is in limbo because it resulted in several controversial conservation decisions in the past. Biologists from FWS must interpret and apply the best available science to their recommendations and likely use considerable discretion in making recommendations for what species to list, how to define those species, and how to recover them. We used semistructured interviews to collect data on FWS biologists' use of discretion to make recommendations for listed species with hybridization issues. These biologists had a large amount of discretion to determine the best available science and how to interpret it but generally deferred to the scientific consensus on the taxonomic status of an organism. Respondents viewed hybridization primarily as a problem in the context of the ESA, although biologists who had experience with hybridization issues were more likely to describe it in more nuanced terms. Many interviewees expressed a desire to continue the current case-by-case approach for handling hybridization issues, but some wanted more guidance on procedures (i.e., a "flexible" hybrid policy). Field-level information can provide critical insight into which policies are working (or not working) and why. The FWS biologists' we interviewed had a high level of discretion, which greatly influenced ESA implementation, particularly in the context of hybridization. © 2016 Society for Conservation Biology.

  19. Natural and Anthropogenic Hybridization in Two Species of Eastern Brazilian Marmosets (Callithrix jacchus and C. penicillata)

    Science.gov (United States)

    Malukiewicz, Joanna; Boere, Vanner; Fuzessy, Lisieux F.; Grativol, Adriana D.; de Oliveira e Silva, Ita; Pereira, Luiz C. M.; Ruiz-Miranda, Carlos R.; Valença, Yuri M.; Stone, Anne C.

    2015-01-01

    Animal hybridization is well documented, but evolutionary outcomes and conservation priorities often differ for natural and anthropogenic hybrids. Among primates, an order with many endangered species, the two contexts can be hard to disentangle from one another, which carries important conservation implications. Callithrix marmosets give us a unique glimpse of genetic hybridization effects under distinct natural and human-induced contexts. Here, we use a 44 autosomal microsatellite marker panel to examine genome-wide admixture levels and introgression at a natural C. jacchus and C. penicillata species border along the São Francisco River in NE Brazil and in an area of Rio de Janeiro state where humans introduced these species exotically. Additionally, we describe for the first time autosomal genetic diversity in wild C. penicillata and expand previous C. jacchus genetic data. We characterize admixture within the natural zone as bimodal where hybrid ancestry is biased toward one parental species or the other. We also show evidence that São Francisco River islands are gateways for bidirectional gene flow across the species border. In the anthropogenic zone, marmosets essentially form a hybrid swarm with intermediate levels of admixture, likely from the absence of strong physical barriers to interspecific breeding. Our data show that while hybridization can occur naturally, the presence of physical, even if leaky, barriers to hybridization is important for maintaining species genetic integrity. Thus, we suggest further study of hybridization under different contexts to set well informed conservation guidelines for hybrid populations that often fit somewhere between “natural” and “man-made.” PMID:26061111

  20. Evidence for the robustness of protein complexes to inter-species hybridization.

    Directory of Open Access Journals (Sweden)

    Jean-Baptiste Leducq

    Full Text Available Despite the tremendous efforts devoted to the identification of genetic incompatibilities underlying hybrid sterility and inviability, little is known about the effect of inter-species hybridization at the protein interactome level. Here, we develop a screening platform for the comparison of protein-protein interactions (PPIs among closely related species and their hybrids. We examine in vivo the architecture of protein complexes in two yeast species (Saccharomyces cerevisiae and Saccharomyces kudriavzevii that diverged 5-20 million years ago and in their F1 hybrids. We focus on 24 proteins of two large complexes: the RNA polymerase II and the nuclear pore complex (NPC, which show contrasting patterns of molecular evolution. We found that, with the exception of one PPI in the NPC sub-complex, PPIs were highly conserved between species, regardless of protein divergence. Unexpectedly, we found that the architecture of the complexes in F1 hybrids could not be distinguished from that of the parental species. Our results suggest that the conservation of PPIs in hybrids likely results from the slow evolution taking place on the very few protein residues involved in the interaction or that protein complexes are inherently robust and may accommodate protein divergence up to the level that is observed among closely related species.

  1. Heritable tissue culture induced genetic variation in sunflower (helianthus annuus l) as a tool for crop improvement

    OpenAIRE

    Encheva Julia; Tsvetkova F.; Ivanov Petar

    2004-01-01

    Immature zygotic embryos from the Bulgarian fertility restorer line R 147 (male component of the commercial hybrid Albena) were used as donor material for induction of direct organogenesis in sunflower (Helianthus annuus L). Range of spontaneous somaclonal variation among the progenies of regenerants has been assessed. Genetic modifications observed in the regenerants included agronomic traits such as oil content in seed, 1000-seed weight, plant height petiole length, internode length, number...

  2. Current and historical hybridization with differential introgression among three species of cyprinid fishes (genus Cyprinella).

    Science.gov (United States)

    Broughton, Richard E; Vedala, Krishna C; Crowl, Tessa M; Ritterhouse, Lauren L

    2011-05-01

    Hybridization is common among freshwater fishes, particular among the Cyprinidae. We used two mitochondrial genes and one nuclear gene to characterize hybridization among two species pairs of Cyprinella in southwestern North America. Genalogical patterns revealed that C. lutrensis and C. venusta are currently hybridizing in several localities producing apparent F(1), F(2) and backcross generations, yet there was no evidence for introgression outside of local hybrid zones. Alternatively, mitochondrial haplotypes from C. lutrensis appear to have introgressed into a C. lepida population in the Nueces River completely replacing the native C. lepida haplotype. There was no evidence of introgression of nuclear DNA and there does not appear to be ongoing hybridization. The population of C. lepida from the nearby Frio River exhibits no evidence of hybridization with C. lutrensis. Thus, contact between C. lutrensis and C. venusta results in the formation of localized hybrid swarms, while contact between C. lutrensis and C. lepida has resulted in complete mitochondrial introgression in the Nueces River or no apparent hybridization in the Frio River. The three different outcomes of contact between these species illustrate the variable nature of interspecific reproductive interactions and provide an excellent system in which to better understand the factors influencing hybridization among freshwater fishes.

  3. Potential Risk of Hybridization in Ex Situ Collections of Two Endangered Species of Sinojackia Hu (Styracaceae)

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Spontaneous hybridization in ex situ facilities can undermine the genetic integrity of ex situ collections and potentially contaminate open-pollinated seeds or seedlings destined for the reintroduction of endangered plant species into the wild. In the present study, the potential risk of hybridization between two endangered Chinese endemic species, namely Sinojackia xylocarpa Hu and S. rehderiana Hu, which are naturally allopatric species but were conserved ex situ in Wuhan Botanical Garden (WBG), Wuhan, China, were investigated over three consecutive years from 2003 to 2005. The entire overlapping flowering period of the two species was 14-20 d and the two species shared the same pollinator insects during the entire flowering season in WBG. The floral isolation between the two species was not an issue in the ex situ collection at WBG. The results suggest an opportunity for pollen transfer between species and a potential risk of genetic introgression and loss of genetic identity of open-pollinated seeds produced in the ex situ collection of these two endangered species. An artificial reciprocal cross between S. xylocarpa and S. rehderiana confirmed that the two congener species could readily set seeds, indicating no post-pollination barriers to hybridization and the importance of spatial isolation as a barrier to inter-specific crossing. Therefore, to manage these crossable species with overlapping flowering times and shared pollination vectors in ex situ facilities, spatial isolation should be carefully considered to minimize the possibility of spontaneous hybridization.

  4. Hybridization in the Ensatina Ring Species, Strong selection against hybrids at a hybrid zone in the ensatina ring species complex and its evolutionary implications

    Energy Technology Data Exchange (ETDEWEB)

    Alexandrino, Joao; Baird, Stuart J.E.; Lawson, Lucinda; Macey, J. Robert; Moritz, Craig; Wake, David B.

    2005-04-22

    The analysis of interactions between lineages at varying levels of genetic divergence can provide insights into the process of speciation through the accumulation of incompatible mutations. Ring species, and especially the Ensatina eschscholtzii system exemplify this approach. The plethodontid salamanders Ensatina eschscholtzii xanthoptica and Ensatina eschscholtzii platensis hybridize in the Central Sierran foothills of California. We compared the genetic structure across two transects (southern and northern Calaveras Co.), one of which was re-sampled over 20 years, and examined diagnostic molecular markers (eight allozyme loci and mitochondrial DNA) and a diagnostic quantitative trait (color pattern). Key results across all studies were: (i) cline centers for all markers were coincident and the zones were narrow, with width estimates of 730m to 2000m; (ii) cline centers at the northern Calaveras transect were coincident between 1981 and 2001, demonstrating repeatability over 5 generations; (iii) there are very few if any putative F1's, but a relatively high number of backcrossed individuals (57-86 percent) in the central portion of transects; (iv) we found substantial linkage disequilibrium in all three studies and strong heterozygote deficit both in northern Calaveras, in 2001, and southern Calaveras. Both linkage disequilibrium and heterozygote deficit show maximum values near the center of the zones (R and Fis, approx. equal to 0.5). Using estimates of cline width and dispersal, we infer strong selection against hybrids (s* approx. equal to 46-75 percent). This is sufficient to promote accumulation of differences at loci that are neutral or under divergent selection, but would still allow for introgression of adaptive alleles. The evidence for strong, but incomplete isolation across this centrally located contact is consistent with theory suggesting a gradual increase in postzygotic incompatibility between allopatric populations subject to divergent

  5. Rape and the prevalence of hybrids in broadly sympatric species: a case study using albatrosses

    Directory of Open Access Journals (Sweden)

    Sievert Rohwer

    2014-06-01

    Full Text Available Conspecific rape often increases male reproductive success. However, the haste and aggression of forced copulations suggests that males may sometimes rape heterospecific females, thus making rape a likely, but undocumented, source of hybrids between broadly sympatric species. We present evidence that heterospecific rape may be the source of hybrids between Black-footed and Laysan Albatrosses (Phoebastria nigripes, and P. immutabilis, respectively. Extensive field studies have shown that paired (but not unpaired males of both of these albatross species use rape as a supplemental reproductive strategy. Between species differences in size, timing of laying, and aggressiveness suggest that Black-footed Albatrosses should be more successful than Laysan Albatrosses in heteropspecific rape attempts, and male Black-footed Albatrosses have been observed attempting to force copulations on female Laysan Albatrosses. Nuclear markers showed that the six hybrids we studied were F1s and mitochondrial markers showed that male Black-footed Albatrosses sired all six hybrids. Long-term gene exchange between these species has been from Black-footed Albatrosses into Laysan Albatrosses, suggesting that the siring asymmetry found in our hybrids has long persisted. If hybrids are sired in heterospecific rapes, they presumably would be raised and sexually imprinted on Laysan Albatrosses, and two unmated hybrids in a previous study courted only Laysan Albatrosses.

  6. Toward breeding new land-sea plant hybrid species irrigable with seawater for dry regions.

    Science.gov (United States)

    Moustafa, Khaled

    2015-01-01

    A plant species growing in sea or coastal saltmarsh is greatly tolerant to high concentrations of salts, and a plant species growing in desert or dry regions is highly tolerant to drought. Breeding a new plant hybrid species from both species by means of cellular grafting, genome fusion or nuclear transfer would generate, at least in theory, a hybrid plant species that should be strongly tolerant to harsh aridity and salinity and would be potentially irrigable with seawater. Such prospective species can be used for example as a fodder, biofuel crop or stabilizer species to protect soil from wind erosion and sandy storms in dry regions. Breeding such species would change the surface of the world and help to solve major challenges of starvation, malnutrition and poverty. Here, I propose potential approaches that would be worthy of investigation toward this purpose.

  7. Altered heterochromatin binding by a hybrid sterility protein in Drosophila sibling species.

    Science.gov (United States)

    Bayes, Joshua J; Malik, Harmit S

    2009-12-11

    Hybrid sterility of the heterogametic sex is one of the first postzygotic reproductive barriers to evolve during speciation, yet the molecular basis of hybrid sterility is poorly understood. We show that the hybrid male sterility gene Odysseus-site homeobox (OdsH) encodes a protein that localizes to evolutionarily dynamic loci within heterochromatin and leads to their decondensation. In Drosophila mauritiana x Drosophila simulans male hybrids, OdsH from D. mauritiana (OdsHmau) acts as a sterilizing factor by associating with the heterochromatic Y chromosome of D. simulans, whereas D. simulans OdsH (OdsHsim) does not. Characterization of sterile hybrid testes revealed that OdsH abundance and localization in the premeiotic phases of spermatogenesis differ between species. These results reveal that rapid heterochromatin evolution affects the onset of hybrid sterility.

  8. Molecular data reveal complex hybridization and a cryptic species of neotropical wild cat.

    Science.gov (United States)

    Trigo, Tatiane C; Schneider, Alexsandra; de Oliveira, Tadeu G; Lehugeur, Livia M; Silveira, Leandro; Freitas, Thales R O; Eizirik, Eduardo

    2013-12-16

    Hybridization among animal species has recently become more recognized as an important phenomenon, especially in the context of recent radiations. Here we show that complex hybridization has led to contrasting patterns of genomic composition among closely related species of the Neotropical cat genus Leopardus. We show strong evidence of ancient hybridization and introgression between the pampas cat (L. colocolo) and northeastern populations of tigrina (L. tigrinus), leading to remarkable cytonuclear discordance in the latter. In contrast, southern tigrina populations show recent and continuing hybridization with Geoffroy's cat (L. geoffroyi), leading to extreme levels of interspecific admixture at their contact zone. Finally, we demonstrate that two seemingly continuous Brazilian tigrina populations show no evidence of ongoing gene flow between them, leading us to support their formal recognition as distinct species, namely L. tigrinus in the northeast and L. guttulus in the south.

  9. Impacts of climate warming on hybrid zone movement: Geographically diffuse and biologically porous "species borders"

    Institute of Scientific and Technical Information of China (English)

    J. Mark Scriber

    2011-01-01

    The ecology and evolutionary biology of insect-plant associations has realized extensive attention, especially during the past 60 years. The classifications (categorical designations) of continuous variation in biodiversity, ranging from global patterns (e.g., latitudinal gradients in species richness/diversity and degree of herbivore feeding specialization) to localized insect-plant associations that span the biospectrum from polyphenisms,polymorphisms, biotypes, demes, host races, to cryptic species, remain academically contentious. Semantic and biosystematic (taxonomical) disagreements sometimes detract from more important ecological and evolutionary processes that drive diversification, the dynarnics of gene flow and local extinctions. This review addresses several aspects of insect specialization, host-associated divergence and ecological (including "hybrid") speciation,with special reference to the climate warming impacts on species borders of hybridizing swallowtail butterflies (Papilionidae). Interspecific hybrid introgression may result in collapse of multi-species communities or increase species numbers via homoploid hybrid speeiation. We may see diverging, merging, or emerging genotypes across hybrid zones,all part of the ongoing processes of evolution. Molecular analyses of genetic mosaics and genomic dynamics with "divergence hitchhiking", combined with ecological, ethological and physiological studies of "species porosity", have already begun to unveil some answers for some important ecological/evolutionary questions. (i) How rapidly can host-associated divergence lead to new species (and why doesn't it always do so, e.g., resulting in "incomplete" speciation)? (ii) How might "speeiation genes" function, and how/where would we find them? (iii) Can oscillations from specialists to generalists and back to specialists help explain global diversity in herbivorous insects? (iv) How could recombinant interspecific hybridization lead to divergence and

  10. Climate-Driven Reshuffling of Species and Genes: Potential Conservation Roles for Species Translocations and Recombinant Hybrid Genotypes

    Directory of Open Access Journals (Sweden)

    Jon Mark Scriber

    2013-12-01

    Full Text Available Comprising 50%–75% of the world’s fauna, insects are a prominent part of biodiversity in communities and ecosystems globally. Biodiversity across all levels of biological classifications is fundamentally based on genetic diversity. However, the integration of genomics and phylogenetics into conservation management may not be as rapid as climate change. The genetics of hybrid introgression as a source of novel variation for ecological divergence and evolutionary speciation (and resilience may generate adaptive potential and diversity fast enough to respond to locally-altered environmental conditions. Major plant and herbivore hybrid zones with associated communities deserve conservation consideration. This review addresses functional genetics across multi-trophic-level interactions including “invasive species” in various ecosystems as they may become disrupted in different ways by rapid climate change. “Invasive genes” (into new species and populations need to be recognized for their positive creative potential and addressed in conservation programs. “Genetic rescue” via hybrid translocations may provide needed adaptive flexibility for rapid adaptation to environmental change. While concerns persist for some conservationists, this review emphasizes the positive aspects of hybrids and hybridization. Specific implications of natural genetic introgression are addressed with a few examples from butterflies, including transgressive phenotypes and climate-driven homoploid recombinant hybrid speciation. Some specific examples illustrate these points using the swallowtail butterflies (Papilionidae with their long-term historical data base (phylogeographical diversity changes and recent (3-decade climate-driven temporal and genetic divergence in recombinant homoploid hybrids and relatively recent hybrid speciation of Papilio appalachiensis in North America. Climate-induced “reshuffling” (recombinations of species composition, genotypes

  11. Absence of postzygotic isolating mechanisms: evidence from experimental hybridization between two species of tropical sea urchins

    Institute of Scientific and Technical Information of China (English)

    M.Aminur RAHMAN; Tsuyoshi UEHARA; Aziz ARSHAD; Fatimah Md.YUSOFF; Mariana Nor SHAMSUDIN

    2012-01-01

    Two reef margin species of tropical sea urchins,Echinometra sp.C (Ec) and Echinometra oblonga (Eo),occur sympatrically on Okinawa intertidal reefs in southern Japan.Hybridization between these species was examined through a series of cross-fertilization experiments.At limited sperm concentrations,where conspecific crosses reached near 100% fertilization,both heterospecific crosses showed high fertilization rates (81%-85%).The compatibility of the gametes demonstrated that if gamete recognition molecules are involved in fertilization of these species,they are not strongly species-specific.We found that conspecific crosses reached peak fertilization levels much faster than did heterospecific crosses,indicating the presence of a prezygotic barrier to hybridization in the gametes.Larval survival,metamorphosis,and juvenile and adult survival of hybrid groups were nearly identical to those of their parent species.Hybrids from crosses in both directions developed normally through larval stages to sexually mature adults,indicating that neither gametic incompatibility nor hybrid inviability appeared to maintain reproductive isolation between these species.In adults,Ec×Ec crosses gave the highest live weight,followed by Eo (ova)×Ec (sperm),Ec (ova)×Eo (sperm),and Eo×Eo.Other growth performance measures (viz.,test size,Aristotle's lantern length,and gonad index) of hybrid groups and their parental siblings showed the same trends.The phenotypic color patterns of the hybrids were closer to the maternal coloration,whereas spine length,tube-foot and gonad spicule characteristics,pedicellaria valve length,and gamete sizes showed intermediate features.Adult F1 hybrids were completely fertile and displayed high fertilization success in F1 backcrosses,eliminating the likelihood that hybrid sterility is a postzygotic mechanism of reproductive isolation.Conversely,intensive surveys failed to find hybrid individuals in the field,suggesting the lack or rarity of natural

  12. Life-History Variation and the Coexistence of a Daphnia Hybrid with Its Parental Species

    NARCIS (Netherlands)

    Spaak, P.; Hoekstra, J.F.

    1995-01-01

    Life history variation and genotype composition were studied in two species of the Daphnia longispina group: the relatively large D. galeata (1.4 mm) and the smaller D. cucullata (0.9 mm). Several multi-locus genotypes of these species were compared with genotypes of their interspecific hybrid, D.

  13. Chromosomal evolution and patterns of introgression in helianthus.

    Science.gov (United States)

    Barb, Jessica G; Bowers, John E; Renaut, Sebastien; Rey, Juan I; Knapp, Steven J; Rieseberg, Loren H; Burke, John M

    2014-07-01

    Knowledge of the nature and extent of karyotypic differences between species provides insight into the evolutionary history of the genomes in question and, in the case of closely related species, the potential for genetic exchange between taxa. We constructed high-density genetic maps of the silverleaf sunflower (Helianthus argophyllus) and Algodones Dune sunflower (H. niveus ssp. tephrodes) genomes and compared them to a consensus map of cultivated sunflower (H. annuus) to identify chromosomal rearrangements between species. The genetic maps of H. argophyllus and H. niveus ssp. tephrodes included 17 linkage groups each and spanned 1337 and 1478 cM, respectively. Comparative analyses revealed greater divergence between H. annuus and H. niveus ssp. tephrodes (13 inverted segments, 18 translocated segments) than between H. annuus and H. argophyllus (10 inverted segments, 8 translocated segments), consistent with their known phylogenetic relationships. Marker order was conserved across much of the genome, with 83 and 64% of the H. argophyllus and H. niveus ssp. tephrodes genomes, respectively, being syntenic with H. annuus. Population genomic analyses between H. annuus and H. argophyllus, which are sympatric across a portion of the natural range of H. annuus, revealed significantly elevated genetic structure in rearranged portions of the genome, indicating that such rearrangements are associated with restricted gene flow between these two species.

  14. Time to a single hybridization event in a group of species with unknown ancestral history.

    Science.gov (United States)

    Bartoszek, Krzysztof; Jones, Graham; Oxelman, Bengt; Sagitov, Serik

    2013-04-07

    We consider a stochastic process for the generation of species which combines a Yule process with a simple model for hybridization between pairs of co-existent species. We assume that the origin of the process, when there was one species, occurred at an unknown time in the past, and we condition the process on producing n species via the Yule process and a single hybridization event. We prove results about the distribution of the time of the hybridization event. In particular we calculate a formula for all moments and show that under various conditions, the distribution tends to an exponential with rate twice that of the birth rate for the Yule process. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Hybridization among three native North American Canis species in a region of natural sympatry.

    Directory of Open Access Journals (Sweden)

    Frank Hailer

    Full Text Available BACKGROUND: Population densities of many species throughout the world are changing due to direct persecution as well as anthropogenic habitat modification. These changes may induce or increase the frequency of hybridization among taxa. If extensive, hybridization can threaten the genetic integrity or survival of endangered species. Three native species of the genus Canis, coyote (C. latrans, Mexican wolf (C. lupus baileyi and red wolf (C. rufus, were historically sympatric in Texas, United States. Human impacts caused the latter two to go extinct in the wild, although they survived in captive breeding programs. Morphological data demonstrate historic reproductive isolation between all three taxa. While the red wolf population was impacted by introgressive hybridization with coyotes as it went extinct in the wild, the impact of hybridization on the Texas populations of the other species is not clear. METHODOLOGY/ PRINCIPAL FINDINGS: We surveyed variation at maternally and paternally inherited genetic markers (mitochondrial control region sequence and Y chromosome microsatellites in coyotes from Texas, Mexican wolves and red wolves from the captive breeding programs, and a reference population of coyotes from outside the historic red wolf range. Levels of variation and phylogenetic analyses suggest that hybridization has occasionally taken place between all three species, but that the impact on the coyote population is very small. CONCLUSION/SIGNIFICANCE: Our results demonstrate that the factors driving introgressive hybridization in sympatric Texan Canis are multiple and complex. Hybridization is not solely determined by body size or sex, and density-dependent effects do not fully explain the observed pattern either. No evidence of hybridization was identified in the Mexican wolf captive breeding program, but introgression appears to have had a greater impact on the captive red wolves.

  16. PERENNIAL HELIANTHUS TAXA IN TÂRGU-MURES CITY AND ITS SURROUNDINGS

    Directory of Open Access Journals (Sweden)

    FILEP RITA

    2010-12-01

    Full Text Available Although in the neighbouring countries several perennial Helianthus taxa have been recorded in the last decade, in Romania only three have been identified so far. The literature and herbaria data of Târgu-Mures date back to the end of the XIXth century, and only refer to H. × multiflorus and H. tuberosus. The aim of this study was to identify the perennial Helianthus taxa in this region and to prepare their current distribution map. The survey was conducted in Târgu Mures city and the neighbouring villages: Livezeni, Sântana de Mures, Sâncraiu de Mures, Sângeorgiu de Mures, and Corunca. Four taxa were identified: H. pauciflorus Nutt., H. × laetiflorus Pers., H. tuberosus L. s.str., and Helianthus tuberosus L. s.l. The first two taxa are cultivated as ornamental plants, H. tuberosus s. str. is cultivated in a few farms, whereas H. tuberosus s. l. is an invasive species that spreads along the rivers.

  17. Rapid discrimination between four seagrass species using hybrid analysis.

    Science.gov (United States)

    Osathanunkul, M; Madesis, P; Ounjai, S; Suwannapoom, C; Jampeetong, A

    2015-04-27

    Biological species are traditionally identified based on their morphological features and the correct identification of species is critical in biological studies. However, some plant types, such as seagrass, are taxonomically problematic and difficult to identify. Furthermore, closely related seagrass species, such as Halophila spp, form a taxonomically unresolved complex. Although some seagrass taxa are easy to recognize, most species are difficult to identify without skilled taxonomic or molecular techniques. Barcoding coupled with High Resolution Melting analysis (BAR-HRM) offers a potentially reliable, rapid, and cost-effective method to confirm species. Here, DNA information of two chloroplast loci was used in combination with HRM analysis to discriminate four species of seagrass collected off the southern coast of Thailand. A distinct melting curve presenting one inflection point was generated for each species using rbcL primers. While the melting profiles of Cymodocea rotundata and Cymodocea serrulata were not statistically different, analysis of the normalized HRM curves produced with the rpoC primers allowed for their discrimination. The Bar-HRM technique showed promise in discriminating seagrass species and with further adaptations and improvements, could make for an effective and power tool for confirming seagrass species.

  18. Ecological constraints limit the fitness of fungal hybrids in the Heterobasidion annosum species complex.

    Science.gov (United States)

    Garbelotto, Matteo; Gonthier, Paolo; Nicolotti, Giovanni

    2007-10-01

    The ability of two closely related species to maintain species boundaries in spite of retained interfertility between them is a documented driving force of speciation. Experimental evidence to support possible interspecific postzygotic isolation mechanisms for organisms belonging to the kingdom Fungi is still missing. Here we report on the outcome of a series of controlled comparative inoculation experiments of parental wild genotypes and F(1) hybrid genotypes between closely related and interfertile taxa within the Heterobasidion annosum fungal species complex. Results indicated that these fungal hybrids are not genetically unfit but can fare as well as parental genotypes when inoculated on substrates favorable to both parents. However, when placed in substrates favoring one of the parents, hybrids are less competitive than the parental genotypes specialized on that substrate. Furthermore, in some but not all fungus x plant combinations, a clear asymmetry in fitness was observed between hybrids carrying identical nuclear genomes but different cytoplasms. This work provides some of the first experimental evidence of ecologically driven postzygotic reinforcement of isolation between closely related fungal species characterized by marked host specificity. Host specialization is one of the most striking traits of a large number of symbiotic and parasitic fungi; thus, we suggest the ecological mechanism proven here to reinforce isolation among Heterobasidion spp. may be generally valid for host-specialized fungi. The validity of this generalization is supported by the low number of known fungal hybrids and by their distinctive feature of being found in substrates different from those colonized by parental species.

  19. Genetic interactions underlying hybrid male sterility in the Drosophila bipectinata species complex.

    Science.gov (United States)

    Mishra, Paras Kumar; Singh, Bashisth Narayan

    2006-06-01

    Understanding genetic mechanisms underlying hybrid male sterility is one of the most challenging problems in evolutionary biology especially speciation. By using the interspecific hybridization method roles of Y chromosome, Major Hybrid Sterility (MHS) genes and cytoplasm in sterility of hybrid males have been investigated in a promising group, the Drosophila bipectinata species complex that consists of four closely related species: D. pseudoananassae, D. bipectinata, D. parabipectinata and D. malerkotliana. The interspecific introgression analyses show that neither cytoplasm nor MHS genes are involved but X-Y interactions may be playing major role in hybrid male sterility between D. pseudoananassae and the other three species. The results of interspecific introgression analyses also show considerable decrease in the number of males in the backcross offspring and all males have atrophied testes. There is a significant positive correlation between sex - ratio distortion and severity of sterility in backcross males. These findings provide evidence that D. pseudoananassae is remotely related with other three species of the D. bipectinata species complex.

  20. Asymmetrical gene flow in a hybrid zone of Hawaiian Schiedea (Caryophyllaceae species with contrasting mating systems.

    Directory of Open Access Journals (Sweden)

    Lisa E Wallace

    Full Text Available Asymmetrical gene flow, which has frequently been documented in naturally occurring hybrid zones, can result from various genetic and demographic factors. Understanding these factors is important for determining the ecological conditions that permitted hybridization and the evolutionary potential inherent in hybrids. Here, we characterized morphological, nuclear, and chloroplast variation in a putative hybrid zone between Schiedea menziesii and S. salicaria, endemic Hawaiian species with contrasting breeding systems. Schiedea menziesii is hermaphroditic with moderate selfing; S. salicaria is gynodioecious and wind-pollinated, with partially selfing hermaphrodites and largely outcrossed females. We tested three hypotheses: 1 putative hybrids were derived from natural crosses between S. menziesii and S. salicaria, 2 gene flow via pollen is unidirectional from S. salicaria to S. menziesii and 3 in the hybrid zone, traits associated with wind pollination would be favored as a result of pollen-swamping by S. salicaria. Schiedea menziesii and S. salicaria have distinct morphologies and chloroplast genomes but are less differentiated at the nuclear loci. Hybrids are most similar to S. menziesii at chloroplast loci, exhibit nuclear allele frequencies in common with both parental species, and resemble S. salicaria in pollen production and pollen size, traits important to wind pollination. Additionally, unlike S. menziesii, the hybrid zone contains many females, suggesting that the nuclear gene responsible for male sterility in S. salicaria has been transferred to hybrid plants. Continued selection of nuclear genes in the hybrid zone may result in a population that resembles S. salicaria, but retains chloroplast lineage(s of S. menziesii.

  1. Epistasis modifies the dominance of loci causing hybrid male sterility in the Drosophila pseudoobscura species group.

    Science.gov (United States)

    Chang, Audrey S; Noor, Mohamed A F

    2010-01-01

    Speciation, the evolution of reproductive isolation between populations, serves as the driving force for generating biodiversity. Postzygotic barriers to gene flow, such as F(1) hybrid sterility and inviability, play important roles in the establishment and maintenance of biological species. F(1) hybrid incompatibilities in taxa that obey Haldane's rule, the observation that the heterogametic sex suffers greater hybrid fitness problems than the homogametic sex, are thought to often result from interactions between recessive-acting X-linked loci and dominant-acting autosomal loci. Because they play such prominent roles in producing hybrid incompatibilities, we examine the dominance and nature of epistasis between alleles derived from Drosophila persimilis that confer hybrid male sterility in the genetic background of its sister species, D. pseudoobscura bogotana. We show that epistasis elevates the apparent dominance of individually recessive-acting QTL such that they can contribute to F(1) hybrid sterility. These results have important implications for assumptions underlying theoretical models of hybrid incompatibilities and may offer a possible explanation for why, to date, identification of dominant-acting autosomal "speciation genes" has been challenging.

  2. Unidirectional hybridization at a species' range boundary: implications for habitat tracking

    DEFF Research Database (Denmark)

    Beatty, Gemma, E.; Philipp, Marianne; Provan, Jim

    2010-01-01

    Aim Introgressive hybridization between a locally rare species and a more abundant congener can drive population extinction via genetic assimilation, or the replacement of the rare species gene pool with that of the common species. To date, however, few studies have assessed the effects of such p....... This could compromise the ability of species to respond to climate change via habitat tracking, although the final outcome of these processes may ultimately depend on the rate of global climate change and its effect on the species' distributions.......Aim Introgressive hybridization between a locally rare species and a more abundant congener can drive population extinction via genetic assimilation, or the replacement of the rare species gene pool with that of the common species. To date, however, few studies have assessed the effects...... hybridization may lead to the extinction of peripheral populations of P. minor where the two species grow sympatrically. Extinction could occur as a result of genetic assimilation where F1s are fertile, or via the removal of unidirectionally pollinated sterile F1s, or by a combination of these processes...

  3. Gene flow and hybridization between numerically imbalanced populations of two duck species in the Falkland Islands.

    Directory of Open Access Journals (Sweden)

    Kevin G McCracken

    Full Text Available Interspecific hybridization is common in plants and animals, particularly in waterfowl (Anatidae. One factor shown to contribute to hybridization is restricted mate choice, which can occur when two species occur in sympatry but one is rare. The Hubbs principle, or "desperation hypothesis," states that under such circumstances the rarer species is more likely to mate with heterospecifics. Here we report interspecific hybridization between two waterfowl species that coexist in broad sympatry and mixed flocks throughout southern South America. Speckled teal (Anas flavirostris and yellow-billed pintails (Anas georgica are abundant in continental South America, but in the Falkland Islands speckled teal outnumber yellow-billed pintails approximately ten to one. Using eight genetic loci (mtDNA and 7 nuclear introns coupled with Bayesian assignment tests and relatedness analysis, we identified a speckled teal x yellow-billed pintail F(1 hybrid female and her duckling sired by a male speckled teal. Although our sample in the Falkland Islands was small, we failed to identify unequivocal evidence of hybridization or introgression in a much larger sample from Argentina using a three-population "isolation with migration" coalescent analysis. While additional data are needed to determine if this event in the Falkland Islands was a rare singular occurrence, our results provide further support for the "desperation hypothesis," which states that scarcity in one population and abundance of another will often lead to hybridization.

  4. Hybridization of powdery mildew strains gives rise to pathogens on novel agricultural crop species.

    Science.gov (United States)

    Menardo, Fabrizio; Praz, Coraline R; Wyder, Stefan; Ben-David, Roi; Bourras, Salim; Matsumae, Hiromi; McNally, Kaitlin E; Parlange, Francis; Riba, Andrea; Roffler, Stefan; Schaefer, Luisa K; Shimizu, Kentaro K; Valenti, Luca; Zbinden, Helen; Wicker, Thomas; Keller, Beat

    2016-02-01

    Throughout the history of agriculture, many new crop species (polyploids or artificial hybrids) have been introduced to diversify products or to increase yield. However, little is known about how these new crops influence the evolution of new pathogens and diseases. Triticale is an artificial hybrid of wheat and rye, and it was resistant to the fungal pathogen powdery mildew (Blumeria graminis) until 2001 (refs. 1,2,3). We sequenced and compared the genomes of 46 powdery mildew isolates covering several formae speciales. We found that B. graminis f. sp. triticale, which grows on triticale and wheat, is a hybrid between wheat powdery mildew (B. graminis f. sp. tritici) and mildew specialized on rye (B. graminis f. sp. secalis). Our data show that the hybrid of the two mildews specialized on two different hosts can infect the hybrid plant species originating from those two hosts. We conclude that hybridization between mildews specialized on different species is a mechanism of adaptation to new crops introduced by agriculture.

  5. Rapid male-specific regulatory divergence and down regulation of spermatogenesis genes in Drosophila species hybrids.

    Directory of Open Access Journals (Sweden)

    Jennifer Ferguson

    Full Text Available In most crosses between closely related species of Drosophila, the male hybrids are sterile and show postmeiotic abnormalities. A series of gene expression studies using genomic approaches have found significant down regulation of postmeiotic spermatogenesis genes in sterile male hybrids. These results have led some to suggest a direct relationship between down regulation in gene expression and hybrid sterility. An alternative explanation to a cause-and-effect relationship between misregulation of gene expression and male sterility is rapid divergence of male sex regulatory elements leading to incompatible interactions in an interspecies hybrid genome. To test the effect of regulatory divergence in spermatogenesis gene expression, we isolated 35 fertile D. simulans strains with D. mauritiana introgressions in either the X, second or third chromosome. We analyzed gene expression in these fertile hybrid strains for a subset of spermatogenesis genes previously reported as significantly under expressed in sterile hybrids relative to D. simulans. We found that fertile autosomal introgressions can cause levels of gene down regulation similar to that of sterile hybrids. We also found that X chromosome heterospecific introgressions cause significantly less gene down regulation than autosomal introgressions. Our results provide evidence that rapid male sex gene regulatory divergence can explain misexpression of spermatogenesis genes in hybrids.

  6. Rapid male-specific regulatory divergence and down regulation of spermatogenesis genes in Drosophila species hybrids.

    Science.gov (United States)

    Ferguson, Jennifer; Gomes, Suzanne; Civetta, Alberto

    2013-01-01

    In most crosses between closely related species of Drosophila, the male hybrids are sterile and show postmeiotic abnormalities. A series of gene expression studies using genomic approaches have found significant down regulation of postmeiotic spermatogenesis genes in sterile male hybrids. These results have led some to suggest a direct relationship between down regulation in gene expression and hybrid sterility. An alternative explanation to a cause-and-effect relationship between misregulation of gene expression and male sterility is rapid divergence of male sex regulatory elements leading to incompatible interactions in an interspecies hybrid genome. To test the effect of regulatory divergence in spermatogenesis gene expression, we isolated 35 fertile D. simulans strains with D. mauritiana introgressions in either the X, second or third chromosome. We analyzed gene expression in these fertile hybrid strains for a subset of spermatogenesis genes previously reported as significantly under expressed in sterile hybrids relative to D. simulans. We found that fertile autosomal introgressions can cause levels of gene down regulation similar to that of sterile hybrids. We also found that X chromosome heterospecific introgressions cause significantly less gene down regulation than autosomal introgressions. Our results provide evidence that rapid male sex gene regulatory divergence can explain misexpression of spermatogenesis genes in hybrids.

  7. IMPROVING WHEAT TRITICUM AESTIVUM L. BY INTERSPECIFIC AND INTERGENERIC HYBRIDIZATION WITH POACEAE FAMILY SPECIES

    Directory of Open Access Journals (Sweden)

    Czaplicki A.Z.

    2012-08-01

    Full Text Available The related species of the family Poaceae (Triticeae are the source of unprecedented new genes that allow the extension of genetic variation of common wheat Triticum aestivum L. These species have similar homoeologous chromosomes and rDNA sequences very similar to T. aestivum L. [1-3]. This allows the introgression of alien genes and their incorporation into the genomes A, B and D of wheat, where they can function permanently in the wheat genetic systems. Many of them have already been transferred to the varieties of T. aestivum L. [4].The experimental material consisted of 28 lines of winter wheat obtained using the interspecific and intergeneric hybridization of T. aestivum L. with alien species T. durum Desf., T. timopheevii Zhuk., Lolium perenne L. and Aegilops speltoides Taush. Among them, 15 lines were developed from the cross-combination with tetraploid species (AABB T. durum Desf., 4 lines from the combination with other tetraploid species of different genome composition (AAGG T. timopheevii Zhuk., 4 lines from cross with L. perenne L. and 5 lines were the double hybrids (three-generic derived with two related species, T. durum Desf. (AABB and Ae. speltoides Taush (BB.The anther culture method was used for obtaining DH lines from these interspecific and intergeneric hybrids. In in vitro culture 124 green plants were regenerated. The method of cluster analysis grouped hybrids in terms of comprehensive general similarity of the studied traits.

  8. Hybridization among distantly related species: Examples from the polyploid genus Curcuma (Zingiberaceae).

    Science.gov (United States)

    Záveská, Eliška; Fér, Tomáš; Šída, Otakar; Marhold, Karol; Leong-Škorničková, Jana

    2016-07-01

    Discerning relationships among species evolved by reticulate and/or polyploid evolution is not an easy task, although it is widely discussed. The economically important genus Curcuma (ca. 120 spp.; Zingiberaceae), broadly distributed in tropical SE Asia, is a particularly interesting example of a group of palaeopolyploid origin whose evolution is driven mainly by hybridization and polyploidization. Although a phylogeny and a new infrageneric classification of Curcuma, based on commonly used molecular markers (ITS and cpDNA), have recently been proposed, significant evolutionary questions remain unresolved. We applied a multilocus approach and a combination of modern analytical methods to this genus to distinguish causes of gene tree incongruence and to identify hybrids and their parental species. Five independent regions of nuclear DNA (DCS, GAPDH, GLOBOSA3, LEAFY, ITS) and four non-coding cpDNA regions (trnL-trnF, trnT-trnL, psbA-trnH and matK), analysed as a single locus, were employed to construct a species tree and hybrid species trees using (*)BEAST and STEM-hy. Detection of hybridogenous species in the dataset was also conducted using the posterior predictive checking approach as implemented in JML. The resulting species tree outlines the relationships among major evolutionary lineages within Curcuma, which were previously unresolved or which conflicted depending upon whether they were based on ITS or cpDNA markers. Moreover, by using the additional markers in tests of plausible topologies of hybrid species trees for C. vamana, C. candida, C. roscoeana and C. myanmarensis suggested by previous molecular and morphological evidence, we found strong evidence that all the species except C. candida are of subgeneric hybrid origin. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Final Critical Habitat for the Pecos Sunflower (Helianthus paradoxus)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — To provide the user with a general idea of areas where final critical habitat for Pecos Sunflower (Helianthus paradoxus) occur. The geographic extent includes...

  10. A stable hybrid containing haploid genomes of two obligate diploid Candida species.

    Science.gov (United States)

    Chakraborty, Uttara; Mohamed, Aiyaz; Kakade, Pallavi; Mugasimangalam, Raja C; Sadhale, Parag P; Sanyal, Kaustuv

    2013-08-01

    Candida albicans and Candida dubliniensis are diploid, predominantly asexual human-pathogenic yeasts. In this study, we constructed tetraploid (4n) strains of C. albicans of the same or different lineages by spheroplast fusion. Induction of chromosome loss in the tetraploid C. albicans generated diploid or near-diploid progeny strains but did not produce any haploid progeny. We also constructed stable heterotetraploid somatic hybrid strains (2n + 2n) of C. albicans and C. dubliniensis by spheroplast fusion. Heterodiploid (n + n) progeny hybrids were obtained after inducing chromosome loss in a stable heterotetraploid hybrid. To identify a subset of hybrid heterodiploid progeny strains carrying at least one copy of all chromosomes of both species, unique centromere sequences of various chromosomes of each species were used as markers in PCR analysis. The reduction of chromosome content was confirmed by a comparative genome hybridization (CGH) assay. The hybrid strains were found to be stably propagated. Chromatin immunoprecipitation (ChIP) assays with antibodies against centromere-specific histones (C. albicans Cse4/C. dubliniensis Cse4) revealed that the centromere identity of chromosomes of each species is maintained in the hybrid genomes of the heterotetraploid and heterodiploid strains. Thus, our results suggest that the diploid genome content is not obligatory for the survival of either C. albicans or C. dubliniensis. In keeping with the recent discovery of the existence of haploid C. albicans strains, the heterodiploid strains of our study can be excellent tools for further species-specific genome elimination, yielding true haploid progeny of C. albicans or C. dubliniensis in future.

  11. Comparative genetics of hybrid incompatibility: sterility in two Solanum species crosses.

    Science.gov (United States)

    Moyle, Leonie C; Nakazato, Takuya

    2008-07-01

    The genetic basis of hybrid sterility can provide insight into the genetic and evolutionary origins of species barriers. We examine the genetics of hybrid incompatibility between two diploid plant species in the plant clade Solanum sect. Lycopersicon. Using a set of near-isogenic lines (NILs) representing the wild species Solanum pennellii (formerly Lycopersicon pennellii) in the genetic background of the cultivated tomato S. lycopersicum (formerly L. esculentum), we found that hybrid pollen and seed infertility are each based on a modest number of loci, male (pollen) and other (seed) incompatibility factors are roughly comparable in number, and seed-infertility QTL act additively or recessively. These findings are remarkably consistent with our previous analysis in a different species pair, S. lycopersicum x S. habrochaites. Data from both studies contrast strongly with data from Drosophila. Finally, QTL for pollen and seed sterility from the two Solanum studies were chromosomally colocalized, indicating a shared evolutionary history for these QTL, a nonrandom genomic distribution of loci causing sterility, and/or a proclivity of certain genes to be involved in hybrid sterility. We show that comparative mapping data can delimit the probable timing of evolution of detected QTL and discern which sterility loci likely evolved earliest among species.

  12. Genetic Segregation and Genomic Hybridization Patterns Support an Allotetraploid Structure and Disomic Inheritance for Salix Species

    Directory of Open Access Journals (Sweden)

    Gianni Barcaccia

    2014-09-01

    Full Text Available The Salix alba L. (white willow—Salix fragilis L. (crack willow complex includes closely related polyploid species, mainly tetraploid (2n = 4x = 76, which are dioecious and hence obligate allogamous. Because little is known about the genome constitution and chromosome behavior of these pure willow trees, genetic analysis of their naturally occurring interspecific polyploid hybrids is still very difficult. A two-way pseudo-testcross strategy was exploited using single-dose AFLP markers in order to assess the main inheritance patterns of tetraploid biotypes (disomy vs. tetrasomy in segregating populations stemmed from S. alba × S. fragilis crosses and reciprocals. In addition, a genomic in situ hybridization (GISH technology was implemented in willow to shed some light on the genome structure of S. alba and S. fragilis species, and their hybrids (allopolyploidy vs. autopolyploidy. The frequency of S. alba-specific molecular markers was almost double compared to that of S. fragilis-specific ones, suggesting the phylogenetic hypothesis of S. fragilis as derivative species from S. alba-like progenitors. Cytogenetic observations at pro-metaphase revealed about half of the chromosome complements being less contracted than the remaining ones, supporting an allopolyploid origin of both S. alba and S. fragilis. Both genetic segregation and genomic hybridization data are consistent with an allotetraploid nature of the Salix species. In particular, the vast majority of the AFLP markers were inherited according to disomic patterns in S. alba × S. fragilis populations and reciprocals. Moreover, in all S. alba against S. fragilis hybridizations and reciprocals, GISH signals were observed only on the contracted chromosomes whereas the non-contracted chromosomes were never hybridized. In conclusion, half of the chromosomes of the pure species S. alba and S. fragilis are closely related and they could share a common diploid ancestor, while the rest of

  13. Dispersal and selection mediate hybridization between a native and invasive species.

    Science.gov (United States)

    Kovach, Ryan P; Muhlfeld, Clint C; Boyer, Matthew C; Lowe, Winsor H; Allendorf, Fred W; Luikart, Gordon

    2015-01-22

    Hybridization between native and non-native species has serious biological consequences, but our understanding of how dispersal and selection interact to influence invasive hybridization is limited. Here, we document the spread of genetic introgression between a native (Oncorhynchus clarkii) and invasive (Oncorhynchus mykiss) trout, and identify the mechanisms influencing genetic admixture. In two populations inhabiting contrasting environments, non-native admixture increased rapidly from 1984 to 2007 and was driven by surprisingly consistent processes. Individual admixture was related to two phenotypic traits associated with fitness: size at spawning and age of juvenile emigration. Fish with higher non-native admixture were larger and tended to emigrate at a younger age--relationships that are expected to confer fitness advantages to hybrid individuals. However, strong selection against non-native admixture was evident across streams and cohorts (mean selection coefficient against genotypes with non-native alleles (s) = 0.60; s.e. = 0.10). Nevertheless, hybridization was promoted in both streams by the continuous immigration of individuals with high levels of non-native admixture from other hybrid source populations. Thus, antagonistic relationships between dispersal and selection are mediating invasive hybridization between these fish, emphasizing that data on dispersal and natural selection are needed to fully understand the dynamics of introgression between native and non-native species. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  14. Interspecific hybridization transfers a previously unknown glyphosate resistance mechanism in Amaranthus species.

    Science.gov (United States)

    Gaines, Todd A; Ward, Sarah M; Bukun, Bekir; Preston, Christopher; Leach, Jan E; Westra, Philip

    2012-01-01

    A previously unknown glyphosate resistance mechanism, amplification of the 5-enolpyruvyl shikimate-3-phosphate synthase gene, was recently reported in Amaranthus palmeri. This evolved mechanism could introgress to other weedy Amaranthus species through interspecific hybridization, representing an avenue for acquisition of a novel adaptive trait. The objective of this study was to evaluate the potential for this glyphosate resistance trait to transfer via pollen from A. palmeri to five other weedy Amaranthus species (Amaranthus hybridus, Amaranthus powellii, Amaranthus retroflexus, Amaranthus spinosus, and Amaranthus tuberculatus). Field and greenhouse crosses were conducted using glyphosate-resistant male A. palmeri as pollen donors and the other Amaranthus species as pollen recipients. Hybridization between A. palmeri and A. spinosus occurred with frequencies in the field studies ranging from <0.01% to 0.4%, and 1.4% in greenhouse crosses. A majority of the A. spinosus × A. palmeri hybrids grown to flowering were monoecious and produced viable seed. Hybridization occurred in the field study between A. palmeri and A. tuberculatus (<0.2%), and between A. palmeri and A. hybridus (<0.01%). This is the first documentation of hybridization between A. palmeri and both A. spinosus and A. hybridus.

  15. Deconvoluting contributions of photoexcited species in polymer-quantum dot hybrid photovoltaic materials

    Science.gov (United States)

    Couderc, Elsa; Greaney, Matthew J.; Thornbury, William; Brutchey, Richard L.; Bradforth, Stephen E.

    2015-01-01

    Ultrafast transient absorption spectroscopy is used in conjunction with spectroelectrochemistry and chemical doping experiments to study the photogeneration of charges in hybrid bulk heterojunction (BHJ) thin films composed of poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b‧]-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) and CdSe nanocrystals. Chemical doping experiments on hybrid and neat PCPDTBT:CdSe thin films are used to deconvolute the spectral signatures of the transient states in the near infrared. We confirm the formation and assignment of oxidized species in chemical doping experiments by comparing the spectral data to that from spectroelectrochemical measurements on hybrid and neat PCPDTBT:CdSe BHJ thin films. The deconvolution procedure allows extraction of the polaron populations in the neat polymer and hybrid thin films.

  16. Evaluation of Alnus species and hybrids. [For biomass energy production

    Energy Technology Data Exchange (ETDEWEB)

    Hall, R.B. (Iowa State Univ., Ames, IA (US). Dept. of Forestry); Burgess, D. (Petawawa National Forestry Inst., Chalk River, Ontario (CA))

    1990-01-01

    Trials of a common set of seed lots representing 39 parents and five species of Alnus have been started in four countries: Belgium, Canada, the UK, and the US. Initial results indicate that cold hardiness is a problem in using A. acuminata but that sufficiently hardy A. rubra sources are available. A. glutinosa had the best growth in the nursery, and A. cordata had the best survival under severe moisture-stress conditions. A summary also is given of a workshop on alder improvement that further demonstrates the potential for developing the genus for biomass energy production. (author).

  17. Hybrid striped bass National Breeding Program: Research towards genetic improvement of a non-model species

    Science.gov (United States)

    The hybrid striped bass (HSB) farming industry at present relies almost totally on wild broodstock for annual production of larvae and fingerlings, and industry efforts to domesticate the parent species of the HSB (white bass: WB, Morone chrysops; striped bass: SB, M. saxatilis) have been fairly lim...

  18. Helikaurolides A-D with a Diterpene-Sesquiterpene Skeleton from Supercritical Fluid Extracts of Helianthus annuus L. var. Arianna.

    Science.gov (United States)

    Torres, Ascensión; Molinillo, José M G; Varela, Rosa M; Casas, Lourdes; Mantell, Casimiro; Martínez de la Ossa, Enrique J; Macías, Francisco A

    2015-10-02

    Four novel compounds (1-4) with an unprecedented skeleton that combines a sesquiterpene lactone and a kaurane diterpene acid were isolated from Helianthus annuus L. var. Arianna extract, which was obtained under supercritical conditions. The structures of 1-4 were elucidated by NMR and MS analyses. The biosynthetic routes involve sesquiterpene lactones and kauranic acid, both of which were previously isolated from this species.

  19. Microarray-based whole-genome hybridization as a tool for determining procaryotic species relatedness

    Energy Technology Data Exchange (ETDEWEB)

    Wu, L.; Liu, X.; Fields, M.W.; Thompson, D.K.; Bagwell, C.E.; Tiedje, J. M.; Hazen, T.C.; Zhou, J.

    2008-01-15

    The definition and delineation of microbial species are of great importance and challenge due to the extent of evolution and diversity. Whole-genome DNA-DNA hybridization is the cornerstone for defining procaryotic species relatedness, but obtaining pairwise DNA-DNA reassociation values for a comprehensive phylogenetic analysis of procaryotes is tedious and time consuming. A previously described microarray format containing whole-genomic DNA (the community genome array or CGA) was rigorously evaluated as a high-throughput alternative to the traditional DNA-DNA reassociation approach for delineating procaryotic species relationships. DNA similarities for multiple bacterial strains obtained with the CGA-based hybridization were comparable to those obtained with various traditional whole-genome hybridization methods (r=0.87, P<0.01). Significant linear relationships were also observed between the CGA-based genome similarities and those derived from small subunit (SSU) rRNA gene sequences (r=0.79, P<0.0001), gyrB sequences (r=0.95, P<0.0001) or REP- and BOX-PCR fingerprinting profiles (r=0.82, P<0.0001). The CGA hybridization-revealed species relationships in several representative genera, including Pseudomonas, Azoarcus and Shewanella, were largely congruent with previous classifications based on various conventional whole-genome DNA-DNA reassociation, SSU rRNA and/or gyrB analyses. These results suggest that CGA-based DNA-DNA hybridization could serve as a powerful, high-throughput format for determining species relatedness among microorganisms.

  20. Identification of misexpressed genetic elements in hybrids between Drosophila-related species

    Science.gov (United States)

    Lopez-Maestre, Hélène; Carnelossi, Elias A. G.; Lacroix, Vincent; Burlet, Nelly; Mugat, Bruno; Chambeyron, Séverine; Carareto, Claudia M. A.; Vieira, Cristina

    2017-01-01

    Crosses between close species can lead to genomic disorders, often considered to be the cause of hybrid incompatibility, one of the initial steps in the speciation process. How these incompatibilities are established and what are their causes remain unclear. To understand the initiation of hybrid incompatibility, we performed reciprocal crosses between two species of Drosophila (D. mojavensis and D. arizonae) that diverged less than 1 Mya. We performed a genome-wide transcriptomic analysis on ovaries from parental lines and on hybrids from reciprocal crosses. Using an innovative procedure of co-assembling transcriptomes, we show that parental lines differ in the expression of their genes and transposable elements. Reciprocal hybrids presented specific gene categories and few transposable element families misexpressed relative to the parental lines. Because TEs are mainly silenced by piwi-interacting RNAs (piRNAs), we hypothesize that in hybrids the deregulation of specific TE families is due to the absence of such small RNAs. Small RNA sequencing confirmed our hypothesis and we therefore propose that TEs can indeed be major players of genome differentiation and be implicated in the first steps of genomic incompatibilities through small RNA regulation. PMID:28091568

  1. Genetic divergence, range expansion and possible homoploid hybrid speciation among pine species in Northeast China.

    Science.gov (United States)

    Ren, G-P; Abbott, R J; Zhou, Y-F; Zhang, L-R; Peng, Y-L; Liu, J-Q

    2012-05-01

    Although homoploid hybrid speciation in plants is probably more common than previously realized, there are few well-documented cases of homoploid hybrid origin in conifers. We examined genetic divergence between two currently widespread pines in Northeast China, Pinus sylvestris var. mongolica and Pinus densiflora, and also whether two narrowly distributed pines in the same region, Pinus funebris and Pinus takahasii, might have originated from the two widespread species by homoploid hybrid speciation. Our results, based on population genetic analysis of chloroplast (cp), mitochondrial (mt) DNA, and nuclear gene sequence variation, showed that the two widespread species were divergent for both cp- and mtDNA variation, and also for haplotype variation at two of eight nuclear gene loci surveyed. Our analysis further indicated that P. sylvestris var. mongolica and P. densiflora remained allopatric during the most severe Quaternary glacial period that occurred in Northeast China, but subsequently exhibited rapid range expansions. P. funebris and P. takahasii, were found to contain a mixture of chlorotypes and nuclear haplotypes that distinguish P. sylvestris var. mongolica and P. densiflora, in support of the hypothesis that they possibly originated via homoploid hybrid speciation following secondary contact and hybridization between P. sylvestris var. mongolica and P. densiflora.

  2. Ephemeral association between gene CG5762 and hybrid male sterility in Drosophila sibling species.

    Science.gov (United States)

    Ma, Daina; Michalak, Pawel

    2011-10-01

    Interspecies divergence in regulatory pathways may result in hybrid male sterility (HMS) when dominance and epistatic interactions between alleles that are functional within one genome are disrupted in hybrid genomes. The identification of genes contributing to HMS and other hybrid dysfunctions is essential for understanding the origin of new species (speciation). Previously, we identified a panel of male-specific loci misexpressed in sterile male hybrids of Drosophila simulans and D. mauritiana relative to parental species. In the current work, we attempt to dissect the genetic associations between HMS and one of the genes, CG5762, a Drosophila-unique locus characterized by rapid sequence divergence within the genus, presumably driven by positive natural selection. CG5762 is underexpressed in sterile backcross males compared with their fertile brothers. In CG5762 heterozygotes, the D. mauritiana allele is consistently overexpressed on both the D. simulans and D. mauritiana backcross genomic background, suggesting a cis-acting regulation factor. There is a significant association between heterozygosity and HMS in hybrid males from early but not later backcross generations. Microsatellite markers spanning CG5762 fail to associate with HMS. These observations lead to a conclusion that CG5762 is not a causative factor of HMS. Although genetic linkage between CG5762 and a neighboring causative introgression cannot be ruled out, it seems that the pattern is most consistent with CG5762 participating in epistatic interactions that are disrupted in flies with HMS.

  3. Plant Regeneration and Somatic Embryogenesis from Immature Embryos Derived through Interspecific Hybridization among Different Carica Species

    Directory of Open Access Journals (Sweden)

    Latifah Amin

    2012-12-01

    Full Text Available Plant regeneration and somatic embryogenesis through interspecific hybridization among different Carica species were studied for the development of a papaya ringspot virus-resistant variety. The maximum fruit sets were recorded from the cross of the native variety C. papaya cv. Shahi with the wild species C. cauliflora. The highest hybrid embryos were recorded at 90 days after pollination and the embryos were aborted at 150 days after pollination. The immature hybrid embryos were used for plant regeneration and somatic embryogenesis. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora showed the highest percentage of germination, as well as plant regeneration on growth regulators free culture medium after 7 days pre-incubation on half-strength MS medium supplemented with 0.2 mg/L BAP, 0.5 mg/L NAA and 60 g/L sucrose. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora produced maximum callus, as well as somatic embryos when cultured on half-strength MS medium containing 5 mg/L 2,4-D, 100 mg/L glutamine, 100 mg/L casein hydrolysate and 60 g/L sucrose. The somatic embryos were transferred into half-strength MS medium containing 0.5 mg/L BAP and 0.2 mg/L NAA and 60 g/L sucrose for maturation. The highest number of regenerated plants per hybrid embryo (10.33 was recorded from the cross of C. papaya cv. Shahi × C. cauliflora. Isoenzyme and dendrogram cluster analysis using UPGMA of the regenerated F1 plantlets confirmed the presence of the hybrid plantlets.

  4. Gene expression disruptions of organism versus organ in Drosophila species hybrids.

    Directory of Open Access Journals (Sweden)

    Daniel J Catron

    Full Text Available Hybrid dysfunctions, such as sterility, may result in part from disruptions in the regulation of gene expression. Studies of hybrids within the Drosophila simulans clade have reported genes expressed above or below the expression observed in their parent species, and such misexpression is associated with male sterility in multigenerational backcross hybrids. However, these studies often examined whole bodies rather than testes or had limited replication using less-sensitive but global techniques. Here, we use a new RNA isolation technique to re-examine hybrid gene expression disruptions in both testes and whole bodies from single Drosophila males by real-time quantitative RT-PCR. We find two early-spermatogenesis transcripts are underexpressed in hybrid whole-bodies but not in assays of testes alone, while two late-spermatogenesis transcripts seem to be underexpressed in both whole-bodies and testes alone. Although the number of transcripts surveyed is limited, these results provide some support for a previous hypothesis that the spermatogenesis pathway in these sterile hybrids may be disrupted sometime after the expression of the early meiotic arrest genes.

  5. Interspecific hybridization in Lily (Lilium): Taxonomic and commercial aspects of using species hybrids in breeding

    NARCIS (Netherlands)

    Lim, K.B.; Barba Gonzalez, R.; Shujun Zhou,; Ramanna, M.S.; Tuyl, van J.M.

    2007-01-01

    With the main goal of generating new groups of lilies, that combine agronomic characteristics of major importance, a large number of crosses were performed among the three most important groups of lilies (Lilium), viz., Asiatic, Longiflorum and Oriental; and to some species, to produce F1 inter-spec

  6. Segregation of Species-Specific Male Attractiveness in F2 Hybrid Lake Malawi Cichlid Fish

    Directory of Open Access Journals (Sweden)

    Ola Svensson

    2011-01-01

    Full Text Available Among the huge radiations of haplochromine cichlid fish in Lakes Malawi and Victoria, closely related species are often reproductively isolated via female mate choice although viable fertile hybrids can be produced when females are confined only with heterospecific males. We generated F2 hybrid males from a cross between a pair of closely related sympatric cichlid fish from Lake Malawi. Laboratory mate choice experiments using microsatellite paternity analysis demonstrated that F2 hybrid males differed significantly in their attractiveness to females of the two parental species, indicating heritable variation in traits involved in mate choice that may contribute to reproductive isolation between these species. We found no significant correlation between male mating success and any measurement of male colour pattern. A simple quantitative genetic model of reproductive isolation suggests that there may be as few as two chromosomal regions controlling species-specific attractiveness. We propose that adaptive radiation of Lake Malawi cichlids could be facilitated by the presence of genes with major effects on mate choice and reproductive isolation.

  7. Ocean warming, a rapid distributional shift, and the hybridization of a coastal fish species.

    Science.gov (United States)

    Potts, Warren M; Henriques, Romina; Santos, Carmen V; Munnik, Kate; Ansorge, Isabelle; Dufois, Francois; Booth, Anthony J; Kirchner, Carola; Sauer, Warwick H H; Shaw, Paul W

    2014-09-01

    Despite increasing awareness of large-scale climate-driven distribution shifts in the marine environment, no study has linked rapid ocean warming to a shift in distribution and consequent hybridization of a marine fish species. This study describes rapid warming (0.8 °C per decade) in the coastal waters of the Angola-Benguela Frontal Zone over the last three decades and a concomitant shift by a temperature sensitive coastal fish species (Argyrosomus coronus) southward from Angola into Namibia. In this context, rapid shifts in distribution across Economic Exclusive Zones will complicate the management of fishes, particularly when there is a lack of congruence in the fisheries policy between nations. Evidence for recent hybridization between A. coronus and a congener, A. inodorus, indicate that the rapid shift in distribution of A. coronus has placed adults of the two species in contact during their spawning events. Ocean warming may therefore revert established species isolation mechanisms and alter the evolutionary history of fishes. While the consequences of the hybridization on the production of the resource remain unclear, this will most likely introduce additional layers of complexity to their management.

  8. Automated classification of tropical shrub species: a hybrid of leaf shape and machine learning approach.

    Science.gov (United States)

    Murat, Miraemiliana; Chang, Siow-Wee; Abu, Arpah; Yap, Hwa Jen; Yong, Kien-Thai

    2017-01-01

    Plants play a crucial role in foodstuff, medicine, industry, and environmental protection. The skill of recognising plants is very important in some applications, including conservation of endangered species and rehabilitation of lands after mining activities. However, it is a difficult task to identify plant species because it requires specialized knowledge. Developing an automated classification system for plant species is necessary and valuable since it can help specialists as well as the public in identifying plant species easily. Shape descriptors were applied on the myDAUN dataset that contains 45 tropical shrub species collected from the University of Malaya (UM), Malaysia. Based on literature review, this is the first study in the development of tropical shrub species image dataset and classification using a hybrid of leaf shape and machine learning approach. Four types of shape descriptors were used in this study namely morphological shape descriptors (MSD), Histogram of Oriented Gradients (HOG), Hu invariant moments (Hu) and Zernike moments (ZM). Single descriptor, as well as the combination of hybrid descriptors were tested and compared. The tropical shrub species are classified using six different classifiers, which are artificial neural network (ANN), random forest (RF), support vector machine (SVM), k-nearest neighbour (k-NN), linear discriminant analysis (LDA) and directed acyclic graph multiclass least squares twin support vector machine (DAG MLSTSVM). In addition, three types of feature selection methods were tested in the myDAUN dataset, Relief, Correlation-based feature selection (CFS) and Pearson's coefficient correlation (PCC). The well-known Flavia dataset and Swedish Leaf dataset were used as the validation dataset on the proposed methods. The results showed that the hybrid of all descriptors of ANN outperformed the other classifiers with an average classification accuracy of 98.23% for the myDAUN dataset, 95.25% for the Flavia dataset and 99

  9. An introduced and a native vertebrate hybridize to form a genetic bridge to a second native species

    Science.gov (United States)

    McDonald, D.B.; Parchman, T.L.; Bower, M.R.; Hubert, W.A.; Rahel, F.J.

    2008-01-01

    The genetic impacts of hybridization between native and introduced species are of considerable conservation concern, while the possibility of reticulate evolution affects our basic understanding of how species arise and shapes how we use genetic data to understand evolutionary diversification. By using mitochondrial NADH dehydrogenase subunit 2 (ND2) sequences and 467 amplified fragment-length polymorphism nuclear DNA markers, we show that the introduced white sucker (Catostomus commersoni) has hybridized with two species native to the Colorado River Basin - the flannelmouth sucker (Catostomus latipinnis) and the bluehead sucker (Catostomus discobolus). Hybrids between the flannelmouth sucker and white sucker have facilitated introgression between the two native species, previously isolated by reproductive barriers, such that individuals exist with contributions from all three genomes. Most hybrids had the mitochondrial haplotype of the introduced white sucker, emphasizing its pivotal role in this three-way hybridization. Our findings highlight how introduced species can threaten the genetic integrity of not only one species but also multiple previously reproductively isolated species. Furthermore, this complex three-way reticulate (as opposed to strictly bifurcating) evolution suggests that seeking examples in other vertebrate systems might be productive. Although the present study involved an introduced species, similar patterns of hybridization could result from natural processes, including stream capture or geological formations (e.g., the Bering land bridge). ?? 2008 by The National Academy of Sciences of the USA.

  10. Species-specific SSR alleles for studies of hybrid cattails (Typha latifolia x T. angustifolia; Typhaceae) in North America.

    Science.gov (United States)

    Snow, Allison A; Travis, Steven E; Wildová, Radka; Fér, Tomás; Sweeney, Patricia M; Marburger, Joy E; Windels, Steven; Kubátová, Barbora; Goldberg, Deborah E; Mutegi, Evans

    2010-12-01

    Studies of hybridizing species are facilitated by the availability of species-specific molecular markers for identifying early- and later-generation hybrids. Cattails are a dominant feature of wetland communities, and a better understanding of the prevalence of hybrids is needed to assess the ecological and evolutionary effects of hybridization. Hybridization between Typha angustifolia and T. latifolia produce long-lived clones, known as Typha ×glauca, which are considered to be invasive. Although morphological variation in cattails makes it difficult to recognize early- and later-generation hybrids, several dominant, species-specific RAPD markers are available. Our goal was to find codominant, species-specific markers with greater polymorphism than RAPDs, to identify later-generation hybrids more efficiently. • We screened nine SSR (simple sequence repeat) loci that were described from populations in Ukraine, and we surveyed 31 cattail populations from the upper Midwest and eastern USA. • Seven SSR loci distinguished the parent taxa and were consistent with known species-specific RAPD markers, allowing easier detection of backcrossing. We used linear discriminant analysis to show that F(1) hybrid phenotypes were intermediate between the parent taxa, while those of backcrossed plants overlapped with the hybrids and their parents. Log(leaf length/leaf width), spike gap length, spike length, and stem diameter explained much of the variation among groups. • We provide the first documentation of backcrossed plants in hybridizing cattail populations in Michigan. The diagnostic SSR loci we identified should be extremely useful for examining the evolutionary and ecology interactions of hybridizing cattails in North America.

  11. Characteristic LDH isozyme electrophoretic patterns in six flatfish species in the Trondheimsfjord, Norway and their utility for the detection of natural species hybrids

    KAUST Repository

    He, Song

    2014-11-19

    Abstract: LDH isozyme electrophoretic patterns among 621 specimens of six different flatfish species collected in the Trondheimsfjord, Norway, were characterized by using the isoelectric focusing in polyacrylamide gel (IFPAG) technique. The LDH locus appears to be a reliable tool for species identification in the Trondheimsfjord flatfishes. Hence, these patterns were used to detect and identify potential hybrids, together with morphological traits. Among all the specimens collected during this study no hybrids were detected. From the actual numbers analysed, the natural hybridization rate between European plaice and European flounder in the Trondheimsfjord can be roughly estimated to be less than 1%. This is substantially lower than corresponding values reported from Baltic and Danish waters.

  12. First evidence for interspecific hybridization between invasive goby species Neogobius fluviatilis and Neogobius melanostomus (Teleostei: Gobiidae: Benthophilinae).

    Science.gov (United States)

    Lindner, K; Cerwenka, A F; Brandner, J; Gertzen, S; Borcherding, J; Geist, J; Schliewen, U K

    2013-06-01

    Two hybrids between the monkey goby Neogobius fluviatilis and the round goby Neogobius melanostomus from the Rhine River were identified by genotyping and morphological comparison. These are the first records of goby-hybrids outside the parent species' native ranges worldwide.

  13. Discrimination of Species and Hybrid Detection in Myriophyllum Spp.: an Introduction to Biodiversity Conservation and Invasion Avoidance

    Directory of Open Access Journals (Sweden)

    R Ghahramanzadeh

    2014-03-01

    Full Text Available Minimizing economical loss through introduction of invasive alien species (IAS in local ecosystem is one of the most important issues in biosecurity. The hybridization potential between non-indigenous and native species has raised concerns due mainly to introgression, which can cause extirpation of native species through gene contamination. In the present study, 71 samples belonging to 12 species from Myriophyllum genus were assessed in Plant Breeding group of Wageningen University. Internal transcribed spacer (ITS was used for identification of invasive species from related native and possible hybrid plants. The result showed that based on universal application, high sequence divergence and species discrimination, ITS is a powerful sequence for the identification of invasive species from related non-invasive foreign and native species. In contrast to morphological data, ITS grouped suspected hybrid plants in to M. heterophyllum and demonstrated that they have not resulted from hybridization. These observations suggest that multiple introduction and genetic recombination among different introduced genotypes or genetic pools could be reasons of non-flowering in suspected hybrid plants. Results showed that molecular markers enable to distinguish invasive plant species from their most closely related congeners. This could be helpful with enforcing a ban on important of such invasive which can help to plant ecosystem and biodiversity stability.

  14. Hybrid Layered Crystal Comprising Polyoxometalate and Surfactant Synthesized from Reduced Mo-Blue Species

    Directory of Open Access Journals (Sweden)

    Keisuke Mikurube

    2013-01-01

    Full Text Available A hybrid layered crystal containing polyoxomolybdate was successfully synthesized from reduced Mo-blue species as starting material. The hybrid crystal, [C5H5N(C16H33]2[β-H2Mo8O26]·2C2H5OH (C16py-H2Mo8, was obtained as a single phase by the gradual oxidation of hexadecylpyridinium-Mo-blue (C16py-Mo-blue hybrid. The X-ray structure analysis revealed that C16py-H2Mo8 comprised β-type octamolybdate anion with two protons (β-H2Mo8. The β-H2Mo8 anions and ethanol molecules of crystallization formed two-dimensional anionic layers. The pyridine rings of C16py did not attend to form the two-dimensional inorganic layers, and the interdigitated C16py bilayers were sandwiched by the β-H2Mo8 anionic layers with periodicity of 18.2 Å. These C16py-H2Mo8 hybrid layered crystals possibly work as a new class of proton conductor.

  15. First flowering hybrid between autotrophic and mycoheterotrophic plant species: breakthrough in molecular biology of mycoheterotrophy.

    Science.gov (United States)

    Ogura-Tsujita, Yuki; Miyoshi, Kazumitsu; Tsutsumi, Chie; Yukawa, Tomohisa

    2014-03-01

    Among land plants, which generally exhibit autotrophy through photosynthesis, about 880 species are mycoheterotrophs, dependent on mycorrhizal fungi for their carbon supply. Shifts in nutritional mode from autotrophy to mycoheterotrophy are usually accompanied by evolution of various combinations of characters related to structure and physiology, e.g., loss of foliage leaves and roots, reduction in seed size, degradation of plastid genome, and changes in mycorrhizal association and pollination strategy. However, the patterns and processes involved in such alterations are generally unknown. Hybrids between autotrophic and mycoheterotrophic plants may provide a breakthrough in molecular studies on the evolution of mycoheterotrophy. We have produced the first hybrid between autotrophic and mycoheterotrophic plant species using the orchid group Cymbidium. The autotrophic Cymbidium ensifolium subsp. haematodes and mycoheterotrophic C. macrorhizon were artificially pollinated, and aseptic germination of the hybrid seeds obtained was promoted by sonication. In vitro flowering was observed five years after seed sowing. Development of foliage leaves, an important character for photosynthesis, segregated in the first generation; that is, some individuals only developed scale leaves on the rhizome and flowering stems. However, all of the flowering plants formed roots, which is identical to the maternal parent.

  16. Species distribution models contribute to determine the effect of climate and interspecific interactions in moving hybrid zones.

    Science.gov (United States)

    Engler, J O; Rödder, D; Elle, O; Hochkirch, A; Secondi, J

    2013-11-01

    Climate is a major factor delimiting species' distributions. However, biotic interactions may also be prominent in shaping geographical ranges, especially for parapatric species forming hybrid zones. Determining the relative effect of each factor and their interaction of the contact zone location has been difficult due to the lack of broad scale environmental data. Recent developments in species distribution modelling (SDM) now allow disentangling the relative contributions of climate and species' interactions in hybrid zones and their responses to future climate change. We investigated the moving hybrid zone between the breeding ranges of two parapatric passerines in Europe. We conducted SDMs representing the climatic conditions during the breeding season. Our results show a large mismatch between the realized and potential distributions of the two species, suggesting that interspecific interactions, not climate, account for the present location of the contact zone. The SDM scenarios show that the southerly distributed species, Hippolais polyglotta, might lose large parts of its southern distribution under climate change, but a similar gain of novel habitat along the hybrid zone seems unlikely, because interactions with the other species (H. icterina) constrain its range expansion. Thus, whenever biotic interactions limit range expansion, species may become 'trapped' if range loss due to climate change is faster than the movement of the contact zone. An increasing number of moving hybrid zones are being reported, but the proximate causes of movement often remain unclear. In a global context of climate change, we call for more interest in their interactions with climate change.

  17. Genome skimming reveals the origin of the Jerusalem Artichoke tuber crop species: neither from Jerusalem nor an artichoke.

    Science.gov (United States)

    Bock, Dan G; Kane, Nolan C; Ebert, Daniel P; Rieseberg, Loren H

    2014-02-01

    The perennial sunflower Helianthus tuberosus, known as Jerusalem Artichoke or Sunchoke, was cultivated in eastern North America before European contact. As such, it represents one of the few taxa that can support an independent origin of domestication in this region. Its tubers were adopted as a source of food and forage when the species was transferred to the Old World in the early 1600s, and are still used today. Despite the cultural and economic importance of this tuber crop species, its origin is debated. Competing hypotheses implicate the occurrence of polyploidization with or without hybridization, and list the annual sunflower H. annuus and five distantly related perennial sunflower species as potential parents. Here, we test these scenarios by skimming the genomes of diverse populations of Jerusalem Artichoke and its putative progenitors. We identify relationships among Helianthus taxa using complete plastomes (151 551 bp), partial mitochondrial genomes (196 853 bp) and 35S (8196 bp) and 5S (514 bp) ribosomal DNA. Our results refute the possibility that Jerusalem Artichoke is of H. annuus ancestry. We provide the first genetic evidence that this species originated recursively from perennial sunflowers of central-eastern North America via hybridization between tetraploid Hairy Sunflower and diploid Sawtooth Sunflower. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  18. Phototropism in seedlings of sunflower, Helianthus annuus L.

    NARCIS (Netherlands)

    Franssen, J.M.

    1980-01-01

    In this thesis the phototropic bending of hypocotyls of sunflower seedlings, Helianthus annuus L., is investigated.

    Chapter 1 gives the reasons for this project. Although phototropism has been studied extensively over the past 100 years, the understanding of

  19. Effect of asymmetric auxin application on Helianthus hypocotyl curvature

    Science.gov (United States)

    Migliaccio, F.; Rayle, D. L.

    1989-01-01

    Indole-3-acetic acid was applied asymmetrically to the hypocotyls of sunflower (Helianthus annuus L.) seedlings. After 5 hours on a clinostat, auxin gradients as small as 1 to 1.3 produced substantial (more than 60 degrees) hypocotyl curvature. This result suggests the asymmetric growth underlying hypocotyl gravitropism can be explained by lateral auxin redistribution.

  20. Transport of glutamine into the xylem of sunflower (Helianthus annuus).

    NARCIS (Netherlands)

    Findenegg, G.R.; Plaisier, W.; Posthumus, M.A.; Melger, W.C.

    1990-01-01

    Sunflower (Helianthus annuus L.) plants were grown on nutrient solution with ammonium nitrogen. After 12 days of growth the ammonium in the nutrient solution was labeled with N (99%). Three hours later glutamine-N in the xylem exudate was labeled for 56% as shown by GC-MS; this percentage increased

  1. Phototropism in seedlings of sunflower, Helianthus annuus L

    NARCIS (Netherlands)

    Franssen, J.M.

    1980-01-01

    In this thesis the phototropic bending of hypocotyls of sunflower seedlings, Helianthus annuus L., is investigated.Chapter 1 gives the reasons for this project. Although phototropism has been studied extensively over the past 100 years, the understanding of the mechanism is far from clear. During th

  2. Distinguishing contemporary hybridization from past introgression with postgenomic ancestry-informative SNPs in strongly differentiated Ciona species.

    Science.gov (United States)

    Bouchemousse, Sarah; Liautard-Haag, Cathy; Bierne, Nicolas; Viard, Frédérique

    2016-11-01

    Biological introductions bring into contact species that can still hybridize. The evolutionary outcomes of such secondary contacts may be diverse (e.g. adaptive introgression from or into the introduced species) but are not yet well examined in the wild. The recent secondary contact between the non-native sea squirt Ciona robusta (formerly known as C. intestinalis type A) and its native congener C. intestinalis (formerly known as C. intestinalis type B), in the Western English Channel, provides an excellent case study to examine. To examine contemporary hybridization between the two species, we developed a panel of 310 ancestry-informative SNPs from a population transcriptomic study. Hybridization rates were examined on 449 individuals sampled in eight sites from the sympatric range and five sites from allopatric ranges. The results clearly showed an almost complete absence of contemporary hybridization between the two species in syntopic localities, with only one-first-generation hybrid and no other genotype compatible with recent backcrosses. Despite the almost lack of contemporary hybridization, shared polymorphisms were observed in sympatric and allopatric populations of both species. Furthermore, one allopatric population from SE Pacific exhibited a higher rate of shared polymorphisms compared to all other C. robusta populations. Altogether, these results indicate that the observed level of shared polymorphism is more probably the outcome of ancient gene flow spread afterwards at a worldwide scale. They also emphasize efficient reproductive barriers preventing hybridization between introduced and native species, which suggests hybridization should not impede too much the expansion and the establishment of the non-native species in its introduction range.

  3. Occasional hybridization between a native and invasive Senecio species in Australia is unlikely to contribute to invasive success.

    Science.gov (United States)

    Dormontt, Eleanor E; Prentis, Peter J; Gardner, Michael G; Lowe, Andrew J

    2017-01-01

    Hybridization between native and invasive species can facilitate introgression of native genes that increase invasive potential by providing exotic species with pre-adapted genes suitable for new environments. In this study we assessed the outcome of hybridization between native Senecio pinnatifolius var. pinnatifolius A.Rich. (dune ecotype) and invasive Senecio madagascariensis Poir. to investigate the potential for introgression of adaptive genes to have facilitated S. madagascariensis spread in Australia. We used amplified fragment length polymorphisms (141 loci) and nuclear microsatellites (2 loci) to genotype a total of 118 adults and 223 seeds from S. pinnatifolius var.pinnatifolius and S. madagascariensis at one allopatric and two shared sites. We used model based clustering and assignment methods to establish whether hybrid seed set and mature hybrids occur in the field. We detected no adult hybrids in any population. Low incidence of hybrid seed set was found at Lennox Head where the contact zone overlapped for 20 m (6% and 22% of total seeds sampled for S. pinnatifolius var. pinnatifolius and S. madagascariensis respectively). One hybrid seed was detected at Ballina where a gap of approximately 150 m was present between species (2% of total seeds sampled for S. madagascariensis). We found no evidence of adult hybrid plants at two shared sites. Hybrid seed set from both species was identified at low levels. Based on these findings we conclude that introgression of adaptive genes from S. pinnatifolius var. pinnatifolius is unlikely to have facilitated S. madagascariensis invasions in Australia. Revisitation of one site after two years could find no remaining S. pinnatifolius var. pinnatifolius, suggesting that contact zones between these species are dynamic and that S. pinnatifolius var. pinnatifolius may be at risk of displacement by S. madagascariensis in coastal areas.

  4. Occasional hybridization between a native and invasive Senecio species in Australia is unlikely to contribute to invasive success

    Directory of Open Access Journals (Sweden)

    Eleanor E. Dormontt

    2017-08-01

    Full Text Available Background Hybridization between native and invasive species can facilitate introgression of native genes that increase invasive potential by providing exotic species with pre-adapted genes suitable for new environments. In this study we assessed the outcome of hybridization between native Senecio pinnatifolius var. pinnatifolius A.Rich. (dune ecotype and invasive Senecio madagascariensis Poir. to investigate the potential for introgression of adaptive genes to have facilitated S. madagascariensis spread in Australia. Methods We used amplified fragment length polymorphisms (141 loci and nuclear microsatellites (2 loci to genotype a total of 118 adults and 223 seeds from S. pinnatifolius var.pinnatifolius and S. madagascariensis at one allopatric and two shared sites. We used model based clustering and assignment methods to establish whether hybrid seed set and mature hybrids occur in the field. Results We detected no adult hybrids in any population. Low incidence of hybrid seed set was found at Lennox Head where the contact zone overlapped for 20 m (6% and 22% of total seeds sampled for S. pinnatifolius var. pinnatifolius and S. madagascariensis respectively. One hybrid seed was detected at Ballina where a gap of approximately 150 m was present between species (2% of total seeds sampled for S. madagascariensis. Conclusions We found no evidence of adult hybrid plants at two shared sites. Hybrid seed set from both species was identified at low levels. Based on these findings we conclude that introgression of adaptive genes from S. pinnatifolius var. pinnatifolius is unlikely to have facilitated S. madagascariensis invasions in Australia. Revisitation of one site after two years could find no remaining S. pinnatifolius var. pinnatifolius, suggesting that contact zones between these species are dynamic and that S. pinnatifolius var. pinnatifolius may be at risk of displacement by S. madagascariensis in coastal areas.

  5. Evidence for mito-nuclear and sex-linked reproductive barriers between the hybrid Italian sparrow and its parent species.

    Directory of Open Access Journals (Sweden)

    Cassandra N Trier

    2014-01-01

    Full Text Available Studies of reproductive isolation between homoploid hybrid species and their parent species have rarely been carried out. Here we investigate reproductive barriers between a recently recognized hybrid bird species, the Italian sparrow Passer italiae and its parent species, the house sparrow P. domesticus and Spanish sparrow P. hispaniolensis. Reproductive barriers can be difficult to study in hybrid species due to lack of geographical contact between taxa. However, the Italian sparrow lives parapatrically with the house sparrow and both sympatrically and parapatrically with the Spanish sparrow. Through whole-transcriptome sequencing of six individuals of each of the two parent species we identified a set of putatively parent species-diagnostic single nucleotide polymorphism (SNP markers. After filtering for coverage, genotyping success (>97% and multiple SNPs per gene, we retained 86 species-informative, genic, nuclear and mitochondrial SNP markers from 84 genes for analysis of 612 male individuals. We show that a disproportionately large number of sex-linked genes, as well as the mitochondria and nuclear genes with mitochondrial function, exhibit sharp clines at the boundaries between the hybrid and the parent species, suggesting a role for mito-nuclear and sex-linked incompatibilities in forming reproductive barriers. We suggest that genomic conflict via interactions between mitochondria and sex-linked genes with mitochondrial function ("mother's curse" at one boundary and centromeric drive at the other may best explain our findings. Hybrid speciation in the Italian sparrow may therefore be influenced by mechanisms similar to those involved in non-hybrid speciation, but with the formation of two geographically separated species boundaries instead of one. Spanish sparrow alleles at some loci have spread north to form reproductive barriers with house sparrows, while house sparrow alleles at different loci, including some on the same chromosome

  6. Possible natural hybridization of two morphologically distinct species of Acropora (Cnidaria, Scleractinia in the Pacific: fertilization and larval survival rates.

    Directory of Open Access Journals (Sweden)

    Naoko Isomura

    Full Text Available Natural hybridization of corals in the Indo-Pacific has been considered rather rare. However, field studies have observed many corals with intermediate interspecific or unusual morphologies. Given that the existence of F1 hybrids with intermediate interspecific morphologies has been proven in the Caribbean, hybrids may also inhabit the Indo-Pacific and occur more frequently than expected. In this study, we focused on two morphologically different species, Acropora florida and A. intermedia, and performed crossing experiments at Akajima Island, Japan. Results showed that these species could hybridize in both directions via eggs and sperm, but that fertilization rates significantly differed according to which species provided eggs. These results are similar to those reported from the Caribbean. Although all embryos developed normally to the planular larval stage, the developmental processes of some hybrid embryos were delayed by approximately 1 h compared with conspecific embryos, suggesting that fertilization occurred 1 h later in interspecific crosses than in intraspecific crosses. More successful hybridization could occur under conditions with low numbers of conspecific colonies. Additionally, a comparison of survival rates between hybrid and intraspecific larvae revealed that intra- and interspecific larvae produced from eggs of A. florida survived for significantly longer than those produced from eggs of A. intermedia. Considering these data, under specific conditions, hybrids can be expected to be produced and survive in nature in the Pacific. Furthermore, we identified one colony with intermediate morphology between A. florida and A. intermedia in the field. This colony was fertilized only by eggs of A. florida, with high fertilization rates, suggesting that this colony would be a hybrid of these two species and might be backcrossed.

  7. Separate Location of Parental Chromosomes in Squashed Metaphases of Hybrid between Hordeum vulgare L. and Four Polyploid, Alien Species

    DEFF Research Database (Denmark)

    Jensen, J.; Linde-Laursen, Ib

    1984-01-01

    In 38 squashed, somatic metaphases of four hybrids between diploid Hordeum vulgare and two tetra-and two hexaploid alien species, each of the H. vulgare chromosomes was identifed, and differentiated from the chromosomes of the other parental species, by its Giemsa C-banding pattern. The H. vulgare...

  8. Interspecific hybridization does not affect the level of fluctuating asymmetry (FA) in the Drosophila bipectinata species complex.

    Science.gov (United States)

    Banerjee, Parul; Singh, B N

    2015-08-01

    The Drosophila bipectinata species complex comprises of four very closely related species namely D. bipectinata, D. parabipectinata, D. malerkotliana and D. pseudoananassae. It was found that irrespective of the evolutionary divergence among the species, FA which is reflective of the developmental precision remains nearly same in four species. During the present study, the level of FA in different morphological traits was studied in interspecific hybrids and compared with that of parental species with the view that it would throw light on the degree of divergence between the parental species. If they have not diverged much, the interspecific hybrids may have a similar FA level, incompatibilities between their genomes being negligible. On the other hand, if there is substantial divergence, the level of FA may be higher due to incompatibility between the genomes of the parental species. The morphological traits taken were sternopleural bristle number and wing length in both males and females and ovariole number and sex-comb tooth number in females and males respectively. However, except in a few cases, we could not detect any significant differences in the level of FA in hybrids as compared to pure species. On the other hand, a number of abnormalities like poor viability, dystrophied ovaries, asymmetrical eyes etc., could be detected in hybrids from crosses involving D. pseudoananassae as one of the parents. Therefore, we conclude that specific developmental pathways are more susceptible to developmental disturbances due to genomic incompatibilities than the large complex system bringing about developmental stability.

  9. HOST SPECIFICITY AND THE GENETIC STRUCTURE OF TWO YUCCA MOTH SPECIES IN A YUCCA HYBRID ZONE.

    Science.gov (United States)

    Leebens-Mack, Jim; Pellmyr, Olle; Brock, Marcus

    1998-10-01

    Host specialization is an important mechanism of diversification among phytophagous insects, especially when they are tightly associated with their hosts. The well-known obligate pollination mutualism between yucca moths and yuccas represent such an association, but the degree of host specificity and modes of specialization in moth evolution is unclear. Here we use molecular tools to test the morphology-based hypothesis that the moths pollinating two yuccas, Yucca baccata and Y. schidigera, are distinct species. Host specificity was assessed in a zone of sympatry where the hosts are known to hybridize. Because the moths are the only pollinators, the plant hybrids are evidence that the moths occasionally perform heterospecific pollination. Nucleotide variation was assessed in a portion of the mitochondrial gene COI, and in an intron within a nuclear lysozyme gene. Moths pollinating Y. baccata and Y. schidigera were inferred to be genetically isolated because there was no overlap in alleles at either locus, and all but one of the moths was found on their native host in the hybrid zone. Moreover, genetic structure was very weak across the range of each moth species: estimates of FST for the lysozyme intron were 0.043 (SE = ± 0.004) and 0.021 (SE = ± 0.006) for the baccata and schidigera pollinators, respectively; estimated FST for COI in the baccata moths was 0.228 (± 0.012), whereas schidigera pollinators were fixed for a single allele. These results reveal a high level of migration among widely separated moth populations. We predict that pollen-mediated gene flow among conspecific yuccas is considerable and hypothesize that geographic separation is a limited barrier both for yuccas and for yucca moths. © 1998 The Society for the Study of Evolution.

  10. Nonrandom patterns of genetic admixture expose the complex historical hybrid origin of unisexual leaf beetle species in the genus Calligrapha.

    Science.gov (United States)

    Montelongo, Tinguaro; Gómez-Zurita, Jesús

    2015-01-01

    Many unisexual animal lineages supposedly arose from hybridization. However, support for their putative hybrid origins mostly comes from indirect methodologies, which are rarely confirmatory. Here we provide compelling data indicating that tetraploid unisexual Calligrapha are true genetic mosaics obtained via analysis of mitochondrial DNA (mtDNA) and allelic variation and coalescence times for three single-copy nuclear genes (CPS, HARS, and Wg) in five of six unisexual Calligrapha and a representative sample of bisexual species. Nuclear allelic diversity in unisexuals consistently segregates in the gene pools of at least two but up to three divergent bisexual species, interpreted as putative parentals of interspecific hybridization crosses. Interestingly, their mtDNA diversity derives from an additional yet undiscovered older evolutionary lineage that is possibly the same for all independently originated unisexual species. One possibly extinct species transferred its mtDNA to several evolutionary lineages in a wave of hybridization events during the Pliocene, whereby descendant species retained a polymorphic mtDNA constitution. Recent hybridizations, in the Pleistocene and always involving females with the old introgressed mtDNA, seemingly occurred in the lineages leading to unisexual species, decoupling mtDNA introgression (and inferences derived from these data, such as timing and parentage) from subsequent acquisition of the new reproductive mode. These results illuminate an unexpected complexity in possible routes to animal unisexuality, with implications for the interpretation of ancient unisexuality. If the origin of unisexuality requires a mechanism where (1) hybridization is a necessary but insufficient condition and (2) multiple bouts of hybridization involving more than two divergent lineages are required, then the origins of several classical unisexual systems may have to be reassessed.

  11. Cross-species amplification of 41 microsatellites in European cyprinids: A tool for evolutionary, population genetics and hybridization studies

    Directory of Open Access Journals (Sweden)

    Gilles André

    2010-05-01

    Full Text Available Abstract Background Cyprinids display the most abundant and widespread species among the European freshwater Teleostei and are known to hybridize quite commonly. Nevertheless, a limited number of markers for conducting comparative differentiation, evolutionary and hybridization dynamics studies are available to date. Findings Five multiplex PCR sets were optimized in order to assay 41 cyprinid-specific polymorphic microsatellite loci (including 10 novel loci isolated from Chondrostoma nasus nasus, Chondrostoma toxostoma toxostoma and Leuciscus leuciscus for 503 individuals (440 purebred specimens and 63 hybrids from 15 European cyprinid species. The level of genetic diversity was assessed in Alburnus alburnus, Alburnoides bipunctatus, C. genei, C. n. nasus, C. soetta, C. t. toxostoma, L. idus, L. leuciscus, Pachychilon pictum, Rutilus rutilus, Squalius cephalus and Telestes souffia. The applicability of the markers was also tested on Abramis brama, Blicca bjoerkna and Scardinius erythrophtalmus specimens. Overall, between 24 and 37 of these markers revealed polymorphic for the investigated species and 23 markers amplified for all the 15 European cyprinid species. Conclusions The developed set of markers demonstrated its performance in discriminating European cyprinid species. Furthermore, it allowed detecting and characterizing hybrid individuals. These microsatellites will therefore be useful to perform comparative evolutionary and population genetics studies dealing with European cyprinids, what is of particular interest in conservation issues and constitutes a tool of choice to conduct hybridization studies.

  12. Discrimination of clostridium species using a magnetic bead based hybridization assay

    Science.gov (United States)

    Pahlow, Susanne; Seise, Barbara; Pollok, Sibyll; Seyboldt, Christian; Weber, Karina; Popp, Jürgen

    2014-05-01

    Clostridium chauvoei is the causative agent of blackleg, which is an endogenous bacterial infection. Mainly cattle and other ruminants are affected. The symptoms of blackleg are very similar to those of malignant edema, an infection caused by Clostridium septicum. [1, 2] Therefore a reliable differentiation of Clostridium chauvoei from other Clostridium species is required. Traditional microbiological detection methods are time consuming and laborious. Additionally, the unique identification is hindered by the overgrowing tendency of swarming Clostridium septicum colonies when both species are present. [1, 3, 4] Thus, there is a crucial need to improve and simplify the specific detection of Clostridium chauvoei and Clostridium septicum. Here we present an easy and fast Clostridium species discrimination method combining magnetic beads and fluorescence spectroscopy. Functionalized magnetic particles exhibit plentiful advantages, like their simple manipulation in combination with a large binding capacity of biomolecules. A specific region of the pathogenic DNA is amplified and labelled with biotin by polymerase chain reaction (PCR). These PCR products were then immobilized on magnetic beads exploiting the strong biotin-streptavidin interaction. The specific detection of different Clostridium species is achieved by using fluorescence dye labeled probe DNA for the hybridization with the immobilized PCR products. Finally, the samples were investigated by fluorescence spectroscopy. [5

  13. The carp-goldfish nucleocytoplasmic hybrid has mitochondria from the carp as the nuclear donor species.

    Science.gov (United States)

    Hu, Guangfu; Zou, Guiwei; Liu, Xiangjiang; Liang, Hongwei; Li, Zhong; Hu, Shaona

    2014-02-25

    It is widely accepted that mitochondria and its DNA (mtDNA) exhibit strict maternal inheritance, with sperm contributing no or non-detectable mitochondria to the next generation. In fish, nuclear transfer (NT) through the combination of a donor nucleus and an enucleated oocyte can produce fertile nucleocytoplasmic hybrids (NCHs) even between different genera and subfamilies. One of the best studied fish NCHs is CyCa produced by transplanting the nuclei plus cytoplasm from the common carp (Cyprinus carpio var. wuyuanensis) into the oocytes of the wild goldfish (Carassius auratus), which has been propagated by self-mating for three generations. These NCH fish thus provide a unique model to study the origin of mitochondria. Here we report the complete mtDNA sequence of the CyCa hybrid and its parental species carp and goldfish as nuclear donor and cytoplasm host, respectively. Interestingly, the mtDNA of NCH fish CyCa is 99.69% identical to the nuclear donor species carp, and 89.25% identical to the oocyte host species goldfish. Furthermore, an amino acid sequence comparison of 13 mitochondrial proteins reveals that CyCa is 99.68% identical to the carp and 87.68% identical to the goldfish. On an mtDNA-based phylogenetic tree, CyCa is clustered with the carp but separated from the goldfish. A real-time PCR analysis revealed the presence of carp mtDNA but the absence of goldfish mtDNA. These results demonstrate--for the first time to our knowledge--that the mtDNA of a NCH such as CyCa fish may originate from its nuclear donor rather than its oocyte host.

  14. Hybrid Lethal Systems in the Drosophila Melanogaster Species Complex. I. the Maternal Hybrid Rescue (Mhr) Gene of Drosophila Simulans

    Science.gov (United States)

    Sawamura, K.; Taira, T.; Watanabe, T. K.

    1993-01-01

    Hybrid females from Drosophila simulans females X Drosophila melanogaster males die as embryos while hybrid males from the reciprocal cross die as late larvae. The other two classes are sterile adults. Letting C, X, and Y designate egg cytoplasm, X, and Y chromosomes, respectively, and subscripts m and s stand for melanogaster and simulans, C(m)X(m)Y(s) males are lethal in the larval stage and are rescued by the previously reported genes, Lhr (Lethal hybrid rescue) in simulans or Hmr (Hybrid male rescue) in melanogaster. We report here another rescue gene located on the second chromosome of simulans, mhr (maternal hybrid rescue) that, when present in the mother, rescues C(s)X(m)X(s) females from embryonic lethality. It has been postulated that the hybrids not carrying the X(s) like C(m)X(m)Y(s) males are larval lethal and that the hybrids carrying both the C(s) and the X(m) like C(s)X(m)X(s) females are embryonic lethal. According to these postulates C(s)X(m)Y(s) males (obtained by mating attached-X simulans females to melanogaster males) should be doubly lethal, at both embryo and larval stages. When both rescuing genes are present, Hmr in the father and mhr in the mother, males of this genotype are fully viable, as predicted. PMID:8436276

  15. Phytoremediation potential of Helianthus annuus L in sewage-irrigated Indo-Gangetic alluvial soils.

    Science.gov (United States)

    Mani, Dinesh; Sharma, Bechan; Kumar, Chitranjan; Pathak, Niraj; Balak, Shiv

    2012-03-01

    The study of phytoremediation potential of Helianthus annuus L was conducted in the sewage-irrigated Indo-Gangetic alluvial soils, India. Calcium @ 1.0% and Zn @ 40 ppm enhanced the yield of H. annuus L and minimized the toxicity of Cr in the investigated soils. The study indicated that H. annuus L is highly sensitive to Cr and Zn in terms of metallic pollution; and may be used as indicator plant. For Cr-phytoremediation, humic acid treatment @ 500 mL/acre induced the Cr-accumulation in roots (p < 0.007) and in shoots (p < 0.015), which was recorded 3.21 and 3.16 mg/kg in root and shoot of H. annuus L, respectively. We suggest that H. annuus L fulfils the necessary condition for efficiently increasing species bioaccumulation after soil treatment with humic acid in Cr-polluted sewage-irrigated soils through soil- plant rhizospheric processes.

  16. Antimony uptake by Zea mays (L.) and Helianthus annuus (L.) from nutrient solution.

    Science.gov (United States)

    Tschan, Martin; Robinson, Brett; Schulin, Rainer

    2008-04-01

    We investigated the extent of Sb uptake by maize (Zea mays) and sunflower (Helianthus annuus) from nutrient solutions containing concentrations from 3 to 24 mg/L of potassium antimonate, with the aim of determining the potential of Sb to enter the food chain. The maximum shoot Sb concentrations in Z. mays and H. annuus were 41 mg/kg and 77 mg/kg dry weight, respectively. There was no significant difference in Sb uptake between species. The average bioaccumulation coefficients (the plant/solution concentration quotients) were 1.02 and 1.93 for Z. mays and H. annuus, respectively. Phosphate addition did not affect plant growth or Sb uptake. Antimony uptake by both Z. mays and H. annuus is unlikely to pose a health risk to animals and humans.

  17. Genome-wide analysis of LTR-retrotransposon diversity and its impact on the evolution of the genus Helianthus (L.).

    Science.gov (United States)

    Mascagni, Flavia; Giordani, Tommaso; Ceccarelli, Marilena; Cavallini, Andrea; Natali, Lucia

    2017-08-18

    Genome divergence by mobile elements activity and recombination is a continuous process that plays a key role in the evolution of species. Nevertheless, knowledge on retrotransposon-related variability among species belonging to the same genus is still limited. Considering the importance of the genus Helianthus, a model system for studying the ecological genetics of speciation and adaptation, we performed a comparative analysis of the repetitive genome fraction across ten species and one subspecies of sunflower, focusing on long terminal repeat retrotransposons at superfamily, lineage and sublineage levels. After determining the relative genome size of each species, genomic DNA was isolated and subjected to Illumina sequencing. Then, different assembling and clustering approaches allowed exploring the repetitive component of all genomes. On average, repetitive DNA in Helianthus species represented more than 75% of the genome, being composed mostly by long terminal repeat retrotransposons. Also, the prevalence of Gypsy over Copia superfamily was observed and, among lineages, Chromovirus was by far the most represented. Although nearly all the same sublineages are present in all species, we found considerable variability in the abundance of diverse retrotransposon lineages and sublineages, especially between annual and perennial species. This large variability should indicate that different events of amplification or loss related to these elements occurred following species separation and should have been involved in species differentiation. Our data allowed us inferring on the extent of interspecific repetitive DNA variation related to LTR-RE abundance, investigating the relationship between changes of LTR-RE abundance and the evolution of the genus, and determining the degree of coevolution of different LTR-RE lineages or sublineages between and within species. Moreover, the data suggested that LTR-RE abundance in a species was affected by the annual or perennial

  18. Surgeons and suture zones: Hybridization among four surgeonfish species in the Indo-Pacific with variable evolutionary outcomes.

    Science.gov (United States)

    DiBattista, Joseph D; Whitney, Jonathan; Craig, Matthew T; Hobbs, Jean-Paul A; Rocha, Luiz A; Feldheim, Kevin A; Berumen, Michael L; Bowen, Brian W

    2016-08-01

    Closely related species can provide valuable insights into evolutionary processes through comparison of their ecology, geographic distribution and the history recorded in their genomes. In the Indo-Pacific, many reef fishes are divided into sister species that come into secondary contact at biogeographic borders, most prominently where Indian Ocean and Pacific Ocean faunas meet. It is unclear whether hybridization in this contact zone represents incomplete speciation, secondary contact, an evolutionary dead-end (for hybrids) or some combination of the above. To address these issues, we conducted comprehensive surveys of two widely-distributed surgeonfish species, Acanthurus leucosternon (N=141) and A. nigricans (N=412), with mtDNA cytochrome b sequences and ten microsatellite loci. These surgeonfishes are found primarily in the Indian and Pacific Oceans, respectively, but overlap at the Christmas and Cocos-Keeling Islands hybrid zone in the eastern Indian Ocean. We also sampled the two other Pacific members of this species complex, A. achilles (N=54) and A. japonicus (N=49), which are known to hybridize with A. nigricans where their ranges overlap. Our results indicate separation between the four species that range from the recent Pleistocene to late Pliocene (235,000-2.25million years ago). The Pacific A. achilles is the most divergent (and possibly ancestral) species with mtDNA dcorr≈0.04, whereas the other two Pacific species (A. japonicus and A. nigricans) are distinguishable only at a population or subspecies level (ΦST=0.6533, P<0.001). Little population structure was observed within species, with evidence of recent population expansion across all four geographic ranges. We detected sharing of mtDNA haplotypes between species and extensive hybridization based on microsatellites, consistent with later generation hybrids but also the effects of allele homoplasy. Despite extensive introgression, 98% of specimens had concordance between mtDNA lineage and

  19. Surgeons and suture zones: Hybridization among four surgeonfish species in the Indo-Pacific with variable evolutionary outcomes

    KAUST Repository

    DiBattista, Joseph

    2016-04-30

    Closely related species can provide valuable insights into evolutionary processes through comparison of their ecology, geographic distribution and the history recorded in their genomes. In the Indo-Pacific, many reef fishes are divided into sister species that come into secondary contact at biogeographic borders, most prominently where Indian Ocean and Pacific Ocean faunas meet. It is unclear whether hybridization in this contact zone represents incomplete speciation, secondary contact, an evolutionary dead-end (for hybrids) or some combination of the above. To address these issues, we conducted comprehensive surveys of two widely-distributed surgeonfish species, Acanthurus leucosternon (N = 141) and A. nigricans (N = 412), with mtDNA cytochrome b sequences and ten microsatellite loci. These surgeonfishes are found primarily in the Indian and Pacific Oceans, respectively, but overlap at the Christmas and Cocos-Keeling Islands hybrid zone in the eastern Indian Ocean. We also sampled the two other Pacific members of this species complex, A. achilles (N = 54) and A. japonicus (N = 49), which are known to hybridize with A. nigricans where their ranges overlap. Our results indicate separation between the four species that range from the recent Pleistocene to late Pliocene (235,000 to 2.25 million years ago). The Pacific A. achilles is the most divergent (and possibly ancestral) species with mtDNA dcorr ≈ 0.04, whereas the other two Pacific species (A. japonicus and A. nigricans) are distinguishable only at a population or subspecies level (ΦST = 0.6533, P < 0.001). Little population structure was observed within species, with evidence of recent population expansion across all four geographic ranges. We detected sharing of mtDNA haplotypes between species and extensive hybridization based on microsatellites, consistent with later generation hybrids but also the effects of allele homoplasy. Despite extensive introgression, 98% of specimens had concordance between mt

  20. Visitantes florales diurnos del girasol (Helianthus annuus, Asterales: Asteraceae en la Argentina Diurnal floral visitors of sunflower (Helianthus annuus, Asterales: Asteraceae in Argentina

    Directory of Open Access Journals (Sweden)

    Juan P. Torretta

    2010-06-01

    Full Text Available El girasol (Helianthus annuus L. es un importante cultivo oleaginoso en la Argentina. Durante tres campañas agrícolas, se determinaron la diversidad y la abundancia del elenco de los visitantes florales diurnos de capítulos de girasol, en ocho sitios que cubren gran parte del área cultivada en Argentina. Setenta y seis morfo-especies de visitantes florales, pertenecientes a ocho órdenes, fueron capturados sobre capítulos de este cultivo. El principal orden fue Hymenoptera, con 37 especies o morfoespecies, de las cuales 32 fueron abejas (Apoidea. Las familias de abejas más representadas fueron Apidae (13, Megachilidae (11 y Halictidae (7. La abeja doméstica (Apis mellifera L. realizó el 93% de las visitas. La composición del elenco de visitantes no mostró un patrón de variación identificable a lo largo del día, ni con respecto a la distancia al borde del cultivo, pero varió entre sitios de muestreo. Se concluye que la abeja doméstica es el principal polinizador del girasol en la Argentina, aunque varias especies nativas de abejas (Melissodes tintinnans (Holmberg, M. rufithorax Brèthes, Melissoptila tandilensis Holmberg, y Megachile spp. podrían ser consideradas como potenciales polinizadores del cultivo.Sunflower (Helianthus annuus L. is an important oilseed crop in Argentina. During three agricultural years, the diversity and abundance of diurnal floral visitors of sunflower heads were determined in eight sites spanning much of this crop's cultivation area in Argentina. Seventysix morpho-species of floral visitors, belonging to eight orders, were captured on sunflower. The principal order was Hymenoptera, with 37 species or morpho-species, of which 32 were bees (Apoidea. The most represented bee families were Apidae (13, Megachilidae (11 and Halictidae (7. The domestic bee (Apis mellifera L. accounted for 93% of the visits. Floral visitor composition did not show an identifiable variation pattern either throughout the day or

  1. Hardwood species classification with DWT based hybrid texture feature extraction techniques

    Indian Academy of Sciences (India)

    Arvind R Yadav; R S Anand; M L Dewal; Sangeeta Gupta

    2015-12-01

    In this work, discrete wavelet transform (DWT) based hybrid texture feature extraction techniques have been used to categorize the microscopic images of hardwood species into 75 different classes. Initially, the DWT has been employed to decompose the image up to 7 levels using Daubechies (db3) wavelet as decomposition filter. Further, first-order statistics (FOS) and four variants of local binary pattern (LBP) descriptors are used to acquire distinct features of these images at various levels. The linear support vector machine (SVM), radial basis function (RBF) kernel SVM and random forest classifiers have been employed for classification. The classification accuracy obtained with state-of-the-art and DWT based hybrid texture features using various classifiers are compared. The DWT based FOS-uniform local binary pattern (DWTFOSLBPu2) texture features at the 4th level of image decomposition have produced best classification accuracy of 97.67 ± 0.79% and 98.40 ± 064% for grayscale and RGB images, respectively, using linear SVM classifier. Reduction in feature dataset by minimal redundancy maximal relevance (mRMR) feature selection method is achieved and the best classification accuracy of 99.00 ± 0.79% and 99.20 ± 0.42% have been obtained for DWT based FOS-LBP histogram Fourier features (DWTFOSLBP-HF) technique at the 5th and 6th levels of image decomposition for grayscale and RGB images, respectively, using linear SVM classifier. The DWTFOSLBP-HF features selected with mRMR method has also established superiority amongst the DWT based hybrid texture feature extraction techniques for randomly divided database into different proportions of training and test datasets.

  2. Separation and determination of arsenic species in water by selective exchange and hybrid resins

    Energy Technology Data Exchange (ETDEWEB)

    Issa, Nureddin Ben [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, Belgrade (Serbia); Rajakovic-Ognjanovic, Vladana N. [Faculty of Civil Engineering, University of Belgrade, Bulevar Kralja Aleksandra 73, Belgrade (Serbia); Marinkovic, Aleksandar D. [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, Belgrade (Serbia); Rajakovic, Ljubinka V., E-mail: ljubinka@tmf.bg.ac.rs [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, Belgrade (Serbia)

    2011-11-07

    Highlights: {yields} A simple and efficient method for separation and determination of arsenic species. {yields} A new hybrid resin HY-AgCl is effective for iAs and oAs analytical separation. {yields} SBAE resin was convenient for the separation of As(III) from As(V) and oAs species. {yields} HY-Fe resin was convenient for the separation of DMAs(V). - Abstract: A simple and efficient method for separation and determination of inorganic arsenic (iAs) and organic arsenic (oAs) in drinking, natural and wastewater was developed. If arsenic is present in water prevailing forms are inorganic acids of As(III) and As(V). oAs can be found in traces as monomethylarsenic acid, MMA(V), and dimethylarsenic acid, DMAs(V). Three types of resins: a strong base anion exchange (SBAE) and two hybrid (HY) resins: HY-Fe and HY-AgCl, based on the activity of hydrated iron oxides and a silver chloride were investigated. It was found that the sorption processes (ion exchange, adsorption and chemisorptions) of arsenic species on SBAE (ion exchange) and HY resins depend on pH values of water. The quantitative separation of molecular and ionic forms of iAs and oAs was achieved by SBAE and pH adjustment, the molecular form of As(III) that exists in the water at pH <8.0 was not bonded with SBAE, which was convenient for direct determination of As(III) concentration in the effluent. HY-Fe resin retained all arsenic species except DMAs(V), which makes possible direct measurements of this specie in the effluent. HY-AgCl resin retained all iAs which was convenient for direct determination of oAs species concentration in the effluent. The selective bonding of arsenic species on three types of resins makes possible the development of the procedure for measuring and calculation of all arsenic species in water. In order to determine capacity of resins the preliminary investigations were performed in batch system and fixed bed flow system. Resin capacities were calculated according to breakthrough

  3. A critical assessment of cross-species detection of gene duplicates using comparative genomic hybridization

    Directory of Open Access Journals (Sweden)

    Renn Suzy CP

    2010-05-01

    Full Text Available Abstract Background Comparison of genomic DNA among closely related strains or species is a powerful approach for identifying variation in evolutionary processes. One potent source of genomic variation is gene duplication, which is prevalent among individuals and species. Array comparative genomic hybridization (aCGH has been successfully utilized to detect this variation among lineages. Here, beyond the demonstration that gene duplicates among species can be quantified with aCGH, we consider the effect of sequence divergence on the ability to detect gene duplicates. Results Using the X chromosome genomic content difference between male D. melanogaster and female D. yakuba and D. simulans, we describe a decrease in the ability to accurately measure genomic content (copy number for orthologs that are only 90% identical. We demonstrate that genome characteristics (e.g. chromatin environment and non-orthologous sequence similarity can also affect the ability to accurately measure genomic content. We describe a normalization strategy and statistical criteria to be used for the identification of gene duplicates among any species group for which an array platform is available from a closely related species. Conclusions Array CGH can be used to effectively identify gene duplication and genome content; however, certain biases are present due to sequence divergence and other genome characteristics resulting from the divergence between lineages. Highly conserved gene duplicates will be more readily recovered by aCGH. Duplicates that have been retained for a selective advantage due to directional selection acting on many loci in one or both gene copies are likely to be under-represented. The results of this study should inform the interpretation of both previously published and future work that employs this powerful technique.

  4. Responses to NaCl stress of cultivated and wild tomato species and their hybrids in callus cultures.

    Science.gov (United States)

    Cano, E A; Pérez-Alfocea, F; Moreno, V; Bolarin, M C

    1996-06-01

    If in vitro culture is to be used for evaluating the salt tolerance of tomato hybrids and segregant populations in a breeding programme, it is previously necessary to get quick and reliable traits. In this work, growth and physiological responses to salinity of two interspecific hybrids between the cultivated tomato (Lycopersicon esculentum Mill) and its wild salt-tolerant species L pennellii are compared to those of their parents. The leaf callus of the first subculture was grown on media amended with 0, 35, 70, 105, 140, 175 and 210 mM NaCl for 40 days. Relative fresh weight growth of callus in response to increased salinity in the culture medium was much greater in L pennellii than in the tomato cultivars, and greater in the hybrids than in the wild species. Moreover, the different salt tolerance degree of hybrids was related to that of female parents. At high salt levels, only Cl(-) accumulation was higher in L pennellii than in tomato cultivars, whereas in the hybrids both Cl(-), and Na(+) accumulation were higher than in their parents. Proline increased with salinity in the callus of all genotypes; these increases were much higher in the tomato cultivars than in L pennellii, and the hybrids showed a similar response to that of the wild species. Salt-treated callus of the tomato cultivars showed significant increases in valine, isoleucine and leucine contents compared to control callus tissue. In contrast, these amino acids in callus tissues of the wild species and hybrids showed a tendency to decrease with increasing salinity.

  5. Helianthus Porteri as a Potential Source for Enhancing the Linoleic Acid Concentration in Sunflower Oil

    Science.gov (United States)

    Confederate Daisy, or Porter's Golden-Eye, Helianthus porteri, formerly known as Viguiera porteri, is an annual sunflower that was recently transferred to the genus Helianthus. It occurs in and around granite outcroppings in the Piedmont regions of North and South Carolina, Alabama, and Georgia. Wil...

  6. Helianthus porteri as a Potential Source for Enhancing Linoleic Acid Concentration in Sunflower Oil

    Science.gov (United States)

    Confederate Daisy, or Porter's Golden-Eye, Helianthus porteri, formerly known as Viguiera porteri, is an annual sunflower that was recently transferred to the genus Helianthus. It occurs in and around granite outcroppings in the Piedmont regions of North and South Carolina, Alabama, and Georgia. Wil...

  7. Chemical Composition and Biological Activity of Essential Oils from Four Nepeta Species and Hybrids against Aedes aegypti (L. (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Abbas Ali

    2015-08-01

    Full Text Available Essential oils of four ornamental species and hybrids of Nepeta: N. racemosa Lam. hybrid ‘Select’, N. sibirica L., N. subsessilis Maxim, and N.×faassenii Bergmans ex Stearn ‘Dropmore were studied for their chemical composition, larvicidal and biting deterrent activity. Water-distilled essential oils from aerial parts of Nepeta species were analyzed by gas chromatography (GC-FID and gas chromatography mass spectrometry (GC-MS. Nepeta racemosa hybrid ‘Select’ and N. ×faassenii ‘Dropmore’ essential oils were rich in 1,8-cineole whereas N. sibirica and N. subsessilis essential oils mainly consisted of sesquiterpenes: (Z- b -farnesene, b -bisabolene, d -cadinene or b -caryophyllene, and caryophyllene oxide. Many Nepeta species essential oils are reported to be rich in nepetalactone isomers, but essential oils from these species contained either very low or no nepetalactone content. In biting deterrent bioassays, essential oils of these Nepeta species and hybrids at 100 µg/cm 2 showed activity similar to DEET at 25 nmol/cm 2 against Aedes aegypti, whereas this activity at the concentration of 10 µg/cm 2 was lower than DEET. All the essential oils showed weak larvicidal activity and mortalities were observed only at highest dose of 125 ppm against Ae. aegypti.

  8. Genome sequence of Cronobacter sakazakii BAA-894 and comparative genomic hybridization analysis with other Cronobacter species.

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    Eva Kucerova

    Full Text Available BACKGROUND: The genus Cronobacter (formerly called Enterobacter sakazakii is composed of five species; C. sakazakii, C. malonaticus, C. turicensis, C. muytjensii, and C. dublinensis. The genus includes opportunistic human pathogens, and the first three species have been associated with neonatal infections. The most severe diseases are caused in neonates and include fatal necrotizing enterocolitis and meningitis. The genetic basis of the diversity within the genus is unknown, and few virulence traits have been identified. METHODOLOGY/PRINCIPAL FINDINGS: We report here the first sequence of a member of this genus, C. sakazakii strain BAA-894. The genome of Cronobacter sakazakii strain BAA-894 comprises a 4.4 Mb chromosome (57% GC content and two plasmids; 31 kb (51% GC and 131 kb (56% GC. The genome was used to construct a 387,000 probe oligonucleotide tiling DNA microarray covering the whole genome. Comparative genomic hybridization (CGH was undertaken on five other C. sakazakii strains, and representatives of the four other Cronobacter species. Among 4,382 annotated genes inspected in this study, about 55% of genes were common to all C. sakazakii strains and 43% were common to all Cronobacter strains, with 10-17% absence of genes. CONCLUSIONS/SIGNIFICANCE: CGH highlighted 15 clusters of genes in C. sakazakii BAA-894 that were divergent or absent in more than half of the tested strains; six of these are of probable prophage origin. Putative virulence factors were identified in these prophage and in other variable regions. A number of genes unique to Cronobacter species associated with neonatal infections (C. sakazakii, C. malonaticus and C. turicensis were identified. These included a copper and silver resistance system known to be linked to invasion of the blood-brain barrier by neonatal meningitic strains of Escherichia coli. In addition, genes encoding for multidrug efflux pumps and adhesins were identified that were unique to C. sakazakii

  9. Validation of microsatellite multiplexes for parentage analysis and species discrimination in two hybridizing species of coral reef fish (Plectropomus spp., Serranidae).

    Science.gov (United States)

    Harrison, Hugo B; Feldheim, Kevin A; Jones, Geoffrey P; Ma, Kayan; Mansour, Hicham; Perumal, Sadhasivam; Williamson, David H; Berumen, Michael L

    2014-06-01

    Microsatellites are often considered ideal markers to investigate ecological processes in animal populations. They are regularly used as genetic barcodes to identify species, individuals, and infer familial relationships. However, such applications are highly sensitive the number and diversity of microsatellite markers, which are also prone to error. Here, we propose a novel framework to assess the suitability of microsatellite datasets for parentage analysis and species discrimination in two closely related species of coral reef fish, Plectropomus leopardus and P. maculatus (Serranidae). Coral trout are important fisheries species throughout the Indo-Pacific region and have been shown to hybridize in parts of the Great Barrier Reef, Australia. We first describe the development of 25 microsatellite loci and their integration to three multiplex PCRs that co-amplify in both species. Using simulations, we demonstrate that the complete suite of markers provides appropriate power to discriminate between species, detect hybrid individuals, and resolve parent-offspring relationships in natural populations, with over 99.6% accuracy in parent-offspring assignments. The markers were also tested on seven additional species within the Plectropomus genus with polymorphism in 28-96% of loci. The multiplex PCRs developed here provide a reliable and cost-effective strategy to investigate evolutionary and ecological dynamics and will be broadly applicable in studies of wild populations and aquaculture brood stocks for these closely related fish species.

  10. Validation of microsatellite multiplexes for parentage analysis and species discrimination in two hybridizing species of coral reef fish (Plectropomus spp., Serranidae)

    KAUST Repository

    Harrison, H.B.

    2014-04-24

    Microsatellites are often considered ideal markers to investigate ecological processes in animal populations. They are regularly used as genetic barcodes to identify species, individuals, and infer familial relationships. However, such applications are highly sensitive the number and diversity of microsatellite markers, which are also prone to error. Here, we propose a novel framework to assess the suitability of microsatellite datasets for parentage analysis and species discrimination in two closely related species of coral reef fish, Plectropomus leopardus and P. maculatus (Serranidae). Coral trout are important fisheries species throughout the Indo-Pacific region and have been shown to hybridize in parts of the Great Barrier Reef, Australia. We first describe the development of 25 microsatellite loci and their integration to three multiplex PCRs that co-amplify in both species. Using simulations, we demonstrate that the complete suite of markers provides appropriate power to discriminate between species, detect hybrid individuals, and resolve parent-offspring relationships in natural populations, with over 99.6% accuracy in parent-offspring assignments. The markers were also tested on seven additional species within the Plectropomus genus with polymorphism in 28-96% of loci. The multiplex PCRs developed here provide a reliable and cost-effective strategy to investigate evolutionary and ecological dynamics and will be broadly applicable in studies of wild populations and aquaculture brood stocks for these closely related fish species. 2014 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

  11. Hybrid male sterility between Drosophila willistoni species is caused by male failure to transfer sperm during copulation.

    Science.gov (United States)

    Civetta, Alberto; Gaudreau, Chelsea

    2015-05-01

    The biological concept of species stresses the importance of understanding what mechanisms maintain species reproductively isolated from each other. Often such mechanisms are divided into premating and postmating, with the latest being the result of either prezygotic or postzygotic isolation barriers. Drosophila willistoni quechua and Drosophila willistoni willistoni are two subspecies that experience reproductive isolation. When a D. w. quechua female is crossed with a D. w. willistoni male, the hybrid males (F1QW) are unable to father progeny; however, the reciprocal cross produces fertile hybrids. Thus, the mechanism of isolation is unidirectional hybrid male sterility. However, the sterile F1QW males contain large amounts of motile sperm. Here we explore whether pre-copulatory or post-copulatory pre-zygotic mechanisms serve as major deterrents in the ability of F1QW males to father progeny. Comparisons of parental and hybrid males copulation durations showed no significant reduction in copulation duration of F1QW males. Interrupted copulations of the parental species confirmed that sperm transfer occurs before the minimum copulation duration registered for F1QW males. However, we found that when females mate with F1QW males, sperm is not present inside the female storage organs and that the lack of sperm in storage is due to failure to transfer sperm rather than spillage or active sperm dumping by females. Sterility of F1QW hybrid males is primarily driven by their inability to transfer sperm during copulation.

  12. Molecular analysis (RAPD-PCR) of inter-strain hybrids of the Paramecium aurelia species complex (Ciliophora, Protozoa).

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    Przyboś, Ewa; Prajer, Małgorzata; Greczek-Stachura, Magdalena

    2005-01-01

    RAPD-PCR analysis showed that species of the Paramecium aurelia complex possessed characteristic band patterns and that the majority were also polymorphic intra-specifically. A comparison of band patterns was performed for some inter-strain hybrids within P. primaurelia, P. tetraurelia, P. pentaurelia, P. septaurelia, P. octaurelia, P. decaurelia, P. dodecaurelia, P. tredecaurelia, and P. quadecaurelia to band patterns characteristic for the parental strains. The investigations, however, did not reveal a close correlation between the degree of inbreeding characteristic for the species and similarity of genotypes. A low similarity of hybrid and parental band patterns was observed in P. octaurelia, P. dodecaurelia, P. quadecaurelia and also P. primaurelia. A high similarity of band patterns of hybrid and parental strains was found in P. tetraurelia, P. septaurelia, P. decaurelia, and P. tredecaurelia.

  13. Visitantes florales nocturnos del girasol (Helianthus annuus, Asterales: Asteraceae en la Argentina Nocturnal floral visitors of sunflower (Helianthus annuus, Asterales: Asteraceae in Argentina

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    Juan P Torretta

    2009-12-01

    Full Text Available El girasol (Helianthus annuus es un cultivo oleaginoso, polinizado por Apis mellifera L. y otras abejas en distintas regiones del mundo. Sin embargo, sus flores también son visitadas por insectos de actividad nocturna. Durante tres campañas agrícolas, se determinó la diversidad de los visitantes nocturnos de capítulos de girasol, en cinco sitios de Argentina. También se estudió el comportamiento de forrajeo de los principales visitantes y la variación de la receptividad estigmática a lo largo del día, con el fin de establecer si estos visitantes contribuyen a la polinización. Al menos 67 especies o morfoespecies pertenecientes a cuatro órdenes de visitantes nocturnos fueron colectadas. El orden más rico y abundante fue Lepidoptera (44 especies o morfoespecies, cinco familias, seguido por Coleoptera (18 especies o morfoespecies, nueve familias, Orthoptera (tres morfoespecies, una familia y Blattaria (dos especies, una familia. Los lepidópteros forrajearon exclusivamente por néctar, mientras que los individuos de los demás órdenes consumieron polen y/o partes florales. El estigma se encontró receptivo durante las horas de luz, con una receptividad máxima al mediodía (12:00 - 14:00. Llamativamente, las flores del girasol son visitadas por mayor número de polillas que de abejas. Debido a que las polillas consumen néctar y potencialmente transportan polen entre flores, en un momento del día en que los estigmas se encuentran menos receptivos, es improbable que polinicen efectivamente el cultivo.Sunflower (Helianthus annuus is an oilseed crop pollinated by Apis mellifera L. and other diurnal bees in different regions of the world. However, their flowers are also visited by insects active at night. During three agricultural years, the diversity of nocturnal visitors to sunflower heads was assessed in five different sites in Argentina. The foraging behavior of the main visitors as well as the stigmatic receptivity variations along

  14. Biomechanics and anatomy of cladode junctions for two Opuntia (Cactaceae) species and their hybrid.

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    Bobich, E G; Nobel, P S

    2001-03-01

    Hybridization between the introduced arborescent Opuntia ficus-indica and the native shrubby O. littoralis has led to populations, referred to as O. "occidentalis," which form thickets that can dominate hillsides of chaparral and that can survive fires. Because the thickets apparently develop via vegetative reproduction, O. "occidentalis" was hypothesized to have a greater ability than its parent species to reproduce vegetatively due to weaker cladode junctions. Of the three taxa, the junctions for O. "occidentalis" had the least amount of wood, despite having cladode masses and junction cross-sectional areas similar to those of O. littoralis. The cladodes of O. "occidentalis" resisted deflection about their junctions the least and their junctions required the least amount of applied mass and the smallest bending moment to fail mechanically. The junction wood for all three taxa consisted mostly of parenchyma, with lesser amounts of cells with thickened secondary cell walls, indicating that some junction strength depended on hydrostatic pressure, especially for terminal junctions. Libriform fibers, which contribute to support and resist bending moments, were about 80% less frequent in the sub-subterminal junctions of O. "occidentalis" than in O. ficus-indica and O. littoralis. Vascular tracheids, which probably reduced shear among cells in the wood, were 90% less frequent in the terminal and sub-subterminal junction wood of O. "occidentalis" compared to O. littoralis. Thus wood characteristics can account for the weaker junctions of O. "occidentalis" compared to those of O. ficus-indica and O. littoralis, which apparently increases the ability of the hybrid to reproduce vegetatively.

  15. Evolution of the leaf economics spectrum in herbs: Evidence from environmental divergences in leaf physiology across Helianthus (Asteraceae).

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    Mason, Chase M; Donovan, Lisa A

    2015-10-01

    The leaf economics spectrum (LES) describes a major axis of plant functional trait variation worldwide, defining suites of leaf traits aligned with resource-acquisitive to resource-conservative ecological strategies. The LES has been interpreted to arise from leaf-level trade-offs among ecophysiological traits common to all plants. However, it has been suggested that the defining leaf-level trade-offs of the LES may not hold within specific functional groups (e.g., herbs) nor within many groups of closely related species, which challenges the usefulness of the LES paradigm across evolutionary scales. Here, we examine the evolution of the LES across 28 species of the diverse herbaceous genus Helianthus (the sunflowers), which occupies a wide range of habitats and climate variation across North America. Using a phylogenetic comparative approach, we find repeated evolution of more resource-acquisitive LES strategies in cooler, drier, and more fertile environments. We also find macroevolutionary correlations among LES traits that recapitulate aspects of the global LES, but with one major difference: leaf mass per area is uncorrelated with leaf lifespan. This indicates that whole-plant processes likely drive variation in leaf lifespan across Helianthus, rather than leaf-level trade-offs. These results suggest that LES patterns do not reflect universal physiological trade-offs at small evolutionary scales. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  16. Potential Hybridization between Two Invasive Termite Species, Coptotermes formosanus and C. gestroi (Isoptera: Rhinotermitidae, and Its Biological and Economic Implications

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    Nan-Yao Su

    2017-01-01

    Full Text Available The Asian subterranean termite, Coptotermes gestroi, is a tropical species but has increasingly been collected from the subtropics in recent years, making it sympatric to the Formosan subterranean termite, C. formosanus in at least three areas, Taiwan, Hawaii, and Florida. Simultaneous flights by these two species were observed since 2013 in South Florida, during which interspecies tandems were observed. Laboratory mating of C. formosanus and C. gestroi alates produced hybrid incipient colonies of larger population size. Studies are underway to examine the presence in the field of hybrid colonies in sympatric areas of Taiwan and Florida. Other biological characteristics of C. formosanus × C. gestroi hybrids being studied include temperature tolerance and preference, colony growth rate, wood-consumption rate, and reproductive fertility. This current research aims to determine the potential establishment of a hybrid termite population in south Florida and Taiwan. It investigates the risk of introgressive hybridization in field populations, with an emphasis on its potential ecological, evolutionary, and economic consequences.

  17. The long-term consequences of hybridization between the two Daphnia species, D. galeata and D. dentifera, in mature habitats

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    Urabe Jotaro

    2011-07-01

    Full Text Available Abstract Background Ecological specializations such as antipredator defense can reinforce morphological and distributional divergence within hybridizing species. Two hybridizing species of Daphnia (D. galeata and D. dentifera are distributed in both Japan and North America; however, these populations have a longer history in Japan than in North America due to the differing impact of the last glaciation on these two regions. We tested the hypothesis that this longer coexistence in Japan would lead to extensive genetic admixture in nuclear and mitochondrial DNA whilst the distinct morphological traits and distributional patterns would be maintained. Results The high level of correspondence among morphological traits, distribution, and mitochondrial and nuclear DNA types for the specimens with D. dentifera mtDNA indicated that the species distinction has been maintained. However, a discordance between mtDNA and nuclear ITS-1 types was observed for most specimens that had D. galeata mtDNA, consistent with the pattern seen between the two species in North America. This observation suggests nuclear introgression from D. dentifera into D. galeata without mitochondrial introgression. Conclusions The separation of morphological traits and distribution ranges of the two hybridizing species in Japan, as well as in North America, has been maintained, despite large differences in climatic and geographical histories of these two regions. Variations in environmental factors, such as predation pressure, might affect maintenance of the distribution, although the further studies are needed to confirm this.

  18. Biosynthesis-Based Quantitative Analysis of 151 Secondary Metabolites of Licorice To Differentiate Medicinal Glycyrrhiza Species and Their Hybrids.

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    Song, Wei; Qiao, Xue; Chen, Kuan; Wang, Ying; Ji, Shuai; Feng, Jin; Li, Kai; Lin, Yan; Ye, Min

    2017-03-07

    Secondary metabolites are usually the bioactive components of medicinal plants. The difference in the secondary metabolisms of closely related plant species and their hybrids has rarely been addressed. In this study, we conducted a holistic secondary metabolomics analysis of three medicinal Glycyrrhiza species (G. uralensis, G. glabra, and G. inflata), which are used as the popular herbal medicine licorice. The Glycyrrhiza species (genotype) for 95 batches of samples were identified by DNA barcodes of the internal transcribed spacer and trnV-ndhC regions, and the chemotypes were revealed by LC/UV- or LC/MS/MS-based quantitative analysis of 151 bioactive secondary metabolites, including 17 flavonoid glycosides, 24 saponins, and 110 free phenolic compounds. These compounds represented key products in the biosynthetic pathways of licorice. For the 76 homozygous samples, the three Glycyrrhiza species showed significant biosynthetic preferences, especially in coumarins, chalcones, isoflavanes, and flavonols. In total, 27 species-specific chemical markers were discovered. The 19 hybrid samples indicated that hybridization could remarkably alter the chemical composition and that the male parent contributed more to the offspring than the female parent did. This is hitherto the largest-scale targeted secondary metabolomics study of medicinal plants and the first report on uniparental inheritance in plant secondary metabolism. The results are valuable for biosynthesis, inheritance, and quality control studies of licorice and other medicinal plants.

  19. Development and Testing of Cool-Season Grass Species, Varieties and Hybrids for Biomass Feedstock Production in Western North America

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    Steven R. Larson

    2017-01-01

    Full Text Available Breeding of native cool-season grasses has the potential to improve forage production and expand the range of bioenergy feedstocks throughout western North America. Basin wildrye (Leymus cinereus and creeping wildrye (Leymus triticoides rank among the tallest and most rhizomatous grasses of this region, respectively. The objectives of this study were to develop interspecific creeping wildrye (CWR × basin wildrye (BWR hybrids and evaluate their biomass yield relative to tetraploid ‘Trailhead’, octoploid ‘Magnar’ and interploidy-hybrid ‘Continental’ BWR cultivars in comparison with other perennial grasses across diverse single-harvest dryland range sites and a two-harvest irrigated production system. Two half-sib hybrid populations were produced by harvesting seed from the tetraploid self-incompatible Acc:641.T CWR genet, which was clonally propagated by rhizomes into isolated hybridization blocks with two tetraploid BWR pollen parents: Acc:636 and ‘Trailhead’. Full-sib hybrid seed was also produced from a controlled cross of tetraploid ‘Rio’ CWR and ‘Trailhead’ BWR plants. In space-planted range plots, the ‘Rio’ CWR × ‘Trailhead’ BWR and Acc:641.T CWR × Acc:636 BWR hybrids displayed high-parent heterosis with 75% and 36% yield advantages, respectively, but the Acc:641.T CWR × ‘Trailhead’ BWR hybrid yielded significantly less than its BWR high-parent in this evaluation. Half-sib CWR × BWR hybrids of Acc:636 and ‘Trailhead’ both yielded as good as or better than available BWR cultivars, with yields similar to switchgrass (Panicum virgatum, in the irrigated sward plots. These results elucidate opportunity to harness genetic variation among native grass species for the development of forage and bioenergy feedstocks in western North America.

  20. North African hybrid sparrows (Passer domesticus, P. hispaniolensis) back from oblivion - ecological segregation and asymmetric mitochondrial introgression between parental species.

    Science.gov (United States)

    Ait Belkacem, Abdelkrim; Gast, Oliver; Stuckas, Heiko; Canal, David; LoValvo, Mario; Giacalone, Gabriele; Päckert, Martin

    2016-08-01

    A stabilized hybrid form of the house sparrow (Passer domesticus) and the Spanish sparrow (P. hispaniolensis) is known as Passer italiae from the Italian Peninsula and a few Mediterranean islands. The growing attention for the Italian hybrid sparrow and increasing knowledge on its biology and genetic constitution greatly contrast the complete lack of knowledge of the long-known phenotypical hybrid sparrow populations from North Africa. Our study provides new data on the breeding biology and variation of mitochondrial DNA in three Algerian populations of house sparrows, Spanish sparrows, and phenotypical hybrids. In two field seasons, the two species occupied different breeding habitats: Spanish sparrows were only found in rural areas outside the cities and bred in open-cup nests built in large jujube bushes. In contrast, house sparrows bred only in the town centers and occupied nesting holes in walls of buildings. Phenotypical hybrids were always associated with house sparrow populations. House sparrows and phenotypical hybrids started breeding mid of March, and most pairs had three successive clutches, whereas Spanish sparrows started breeding almost one month later and had only two successive clutches. Mitochondrial introgression is strongly asymmetric because about 75% of the rural Spanish sparrow population carried house sparrow haplotypes. In contrast, populations of the Italian hybrid form, P. italiae, were genetically least diverse among all study populations and showed a near-fixation of house sparrow haplotypes that elsewhere were extremely rare or that were even unique for the Italian Peninsula. Such differences between mitochondrial gene pools of Italian and North African hybrid sparrow populations provide first evidence that different demographic histories have shaped the extant genetic diversity observed on both continents.

  1. Identification of transcriptome SNPs between Xiphophorus lines and species for assessing allele specific gene expression within F₁ interspecies hybrids.

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    Shen, Yingjia; Catchen, Julian; Garcia, Tzintzuni; Amores, Angel; Beldorth, Ion; Wagner, Jonathan; Zhang, Ziping; Postlethwait, John; Warren, Wes; Schartl, Manfred; Walter, Ronald B

    2012-01-01

    Variations in gene expression are essential for the evolution of novel phenotypes and for speciation. Studying allelic specific gene expression (ASGE) within interspecies hybrids provides a unique opportunity to reveal underlying mechanisms of genetic variation. Using Xiphophorus interspecies hybrid fishes and high-throughput next generation sequencing technology, we were able to assess variations between two closely related vertebrate species, Xiphophorus maculatus and Xiphophorus couchianus, and their F(1) interspecies hybrids. We constructed transcriptome-wide SNP polymorphism sets between two highly inbred X. maculatus lines (JP 163 A and B), and between X. maculatus and a second species, X. couchianus. The X. maculatus JP 163 A and B parental lines have been separated in the laboratory for ≈70 years and we were able to identify SNPs at a resolution of 1 SNP per 49 kb of transcriptome. In contrast, SNP polymorphisms between X. couchianus and X. maculatus species, which diverged ≈5-10 million years ago, were identified about every 700 bp. Using 6524 transcripts with identified SNPs between the two parental species (X. maculatus and X. couchianus), we mapped RNA-seq reads to determine ASGE within F(1) interspecies hybrids. We developed an in silico X. couchianus transcriptome by replacing 90,788 SNP bases for X. maculatus transcriptome with the consensus X. couchianus SNP bases and provide evidence that this procedure overcomes read mapping biases. Employment of the in silico reference transcriptome and tolerating 5 mismatches during read mapping allow direct assessment of ASGE in the F(1) interspecies hybrids. Overall, these results show that Xiphophorus is a tractable vertebrate experimental model to investigate how genetic variations that occur during speciation may affect gene interactions and the regulation of gene expression.

  2. Genetic Evidence of Hybridization between the Endangered Native Species Iguana delicatissima and the Invasive Iguana iguana (Reptilia, Iguanidae in the Lesser Antilles: Management Implications.

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    Barbara Vuillaume

    Full Text Available The worldwide increase of hybridization in different groups is thought to have become more important with the loss of isolating barriers and the introduction of invasive species. This phenomenon could result in the extinction of endemic species. This study aims at investigating the hybridization dynamics between the endemic and threatened Lesser Antillean iguana (Iguana delicatissima and the invasive common green iguana (Iguana iguana in the Lesser Antilles, as well as assessing the impact of interspecific hybridization on the decline of I. delicatissima. 59 I. delicatissima (5 localities, 47 I. iguana (12 localities and 27 hybrids (5 localities, who were all identified based on morphological characters, have been genotyped at 15 microsatellites markers. We also sequenced hybrids using ND4 mitochondrial loci to further investigate mitochondrial introgression. The genetic clustering of species and hybrid genetic assignment were performed using a comparative approach, through the implementation of a Discriminant Analysis of Principal Component (DAPC based on statistics, as well as genetic clustering approaches based on the genetic models of several populations (Structure, NewHybrids and HIest, in order to get full characterization of hybridization patterns and introgression dynamics across the islands. The iguanas identified as hybrids in the wild, thanks to morphological analysis, were all genetically F1, F2, or backcrosses. A high proportion of individuals were also the result of a longer-term admixture. The absence of reproductive barriers between species leads to hybridization when species are in contact. Yet morphological and behavioral differences between species could explain why males I. iguana may dominate I. delicatissima, thus resulting in short-term species displacement and extinction by hybridization and recurrent introgression from I. iguana toward I. delicatissima. As a consequence, I. delicatissima gets eliminated through

  3. Gene flow and hybridization between numerically imbalanced populations of two duck species on the subantarctic island of South Georgia.

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    Kevin G McCracken

    Full Text Available Hybridization is common between species of animals, particularly in waterfowl (Anatidae. One factor shown to promote hybridization is restricted mate choice, which can occur when 2 species occur in sympatry but one is rare. According to the Hubbs principle, or "desperation hypothesis," the rarer species is more likely to mate with heterospecifics. We report the second of 2 independent examples of hybridization between 2 species of ducks inhabiting island ecosystems in the Subantarctic and South Atlantic Ocean. Yellow-billed pintails (Anas georgica and speckled teal (Anas flavirostris are abundant in continental South America, where they are sympatric and coexist in mixed flocks. But on South Georgia, an isolated island in the Subantarctic, the pintail population of approximately 6000 pairs outnumbers a small breeding population of speckled teal 300∶1. Using 6 genetic loci (mtDNA and 5 nuclear introns and Bayesian assignment tests coupled with coalescent analyses, we identified hybrid-origin speckled teal alleles in 2 pintails on South Georgia. While it is unclear whether introgression has also occurred into the speckled teal population, our data suggest that this hybridization was not a recent event, but occurred some time ago. We also failed to identify unequivocal evidence of introgression in a much larger sample of pintails and speckled teal from Argentina using a 3-population "Isolation-with-Migration" coalescent analysis. Combined with parallel findings of hybridization between these same 2 duck species in the Falkland Islands, where population ratios are reversed and pintails are outnumbered by speckled teal 1:10, our results provide further support for the desperation hypothesis, which predicts that scarcity in one population and abundance of another will often lead to hybridization. While the South Georgia pintail population appears to be thriving, it's possible that low density of conspecific mates and inverse density dependence

  4. Antioxidant properties and composition of aqueous extracts from Mentha species, hybrids, varieties, and cultivars.

    Science.gov (United States)

    Dorman, H J Damien; Koşar, Müberra; Kahlos, Kirsti; Holm, Yvonne; Hiltunen, Raimo

    2003-07-30

    Water-soluble extracts from the Mentha species M. aquatica L. and M. haplocalyx Briq., the hybrids M. x dalmatica L. and M. x verticillata L., the varieties M. arvensis var. japanensis [M. arvensis L. var. piperascens Holmes ex Christ] and M. spicata L. var. crispa Benth, and M. x piperita L. "Frantsila", M. "Morocco", and M. "Native Wilmet" cultivars were screened for potential antioxidative properties. These properties included iron(III) reduction, iron(II) chelation, 1,1-diphenyl-2-picrylhydrazyl radical scavenging, and the ability to inhibit iron(III)-ascorbate-catalyzed hydroxyl radical-mediated brain phospholipid peroxidation. Total phenol content and qualitative and quantitative compositional analyses of each extract were also made. The extracts demonstrated varying degrees of efficacy in each assay, with the M. x piperita "Frantsila" extract being better than the other extracts, except for ferrous iron chelation. With the exception of iron chelation, it appeared that the level of activity identified was strongly associated with the phenolic content.

  5. Using comparative genomic hybridization to survey genomic sequence divergence across species: a proof-of-concept from Drosophila

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    Kulathinal Rob J

    2010-04-01

    Full Text Available Abstract Background Genome-wide analysis of sequence divergence among species offers profound insights into the evolutionary processes that shape lineages. When full-genome sequencing is not feasible for a broad comparative study, we propose the use of array-based comparative genomic hybridization (aCGH in order to identify orthologous genes with high sequence divergence. Here we discuss experimental design, statistical power, success rate, sources of variation and potential confounding factors. We used a spotted PCR product microarray platform from Drosophila melanogaster to assess sequence divergence on a gene-by-gene basis in three fully sequenced heterologous species (D. sechellia, D. simulans, and D. yakuba. Because complete genome assemblies are available for these species this study presents a powerful test for the use of aCGH as a tool to measure sequence divergence. Results We found a consistent and linear relationship between hybridization ratio and sequence divergence of the sample to the platform species. At higher levels of sequence divergence (D. melanogaster ~84% of features had significantly less hybridization to the array in the heterologous species than the platform species, and thus could be identified as "diverged". At lower levels of divergence (≥ 97% identity, only 13% of genes were identified as diverged. While ~40% of the variation in hybridization ratio can be accounted for by variation in sequence identity of the heterologous sample relative to D. melanogaster, other individual characteristics of the DNA sequences, such as GC content, also contribute to variation in hybridization ratio, as does technical variation. Conclusions Here we demonstrate that aCGH can accurately be used as a proxy to estimate genome-wide divergence, thus providing an efficient way to evaluate how evolutionary processes and genomic architecture can shape species diversity in non-model systems. Given the increased number of species for which

  6. Interspecific hybridization and bioactive alkaloid variation increases diversity in endophytic Epichloë species of Bromus laevipes.

    Science.gov (United States)

    Charlton, Nikki D; Craven, Kelly D; Afkhami, Michelle E; Hall, Bradley A; Ghimire, Sita R; Young, Carolyn A

    2014-10-01

    Studying geographic variation of microbial mutualists, especially variation in traits related to benefits they provide their host, is critical for understanding how these associations impact key ecological processes. In this study, we investigate the phylogenetic population structure of Epichloë species within Bromus laevipes, a native cool-season bunchgrass found predominantly in California. Phylogenetic classification supported inference of three distinct Epichloë taxa, of which one was nonhybrid and two were interspecific hybrids. Inheritance of mating-type idiomorphs revealed that at least one of the hybrid species arose from independent hybridization events. We further investigated the geographic variation of endophyte-encoded alkaloid genes, which is often associated with key benefits of natural enemy protection for the host. Marker diversity at the ergot alkaloid, loline, indole-diterpene, and peramine loci revealed four alkaloid genotypes across the three identified Epichloë species. Predicted chemotypes were tested using endophyte-infected plant material that represented each endophyte genotype, and 11 of the 13 predicted alkaloids were confirmed. This multifaceted approach combining phylogenetic, genotypic, and chemotypic analyses allowed us to reconstruct the diverse evolutionary histories of Epichloë species present within B. laevipes and highlight the complex and dynamic processes underlying these grass-endophyte symbioses.

  7. Chloroplast SSR polymorphisms in the Compositae and the mode of organellar inheritance in Helianthus annuus.

    Science.gov (United States)

    Wills, David M; Hester, Melissa L; Liu, Aizhong; Burke, John M

    2005-03-01

    Because organellar genomes are often uniparentally inherited, chloroplast (cp) and mitochondrial (mt) DNA polymorphisms have become the markers of choice for investigating evolutionary issues such as sex-biased dispersal and the directionality of introgression. To the extent that organellar inheritance is strictly maternal, it has also been suggested that the insertion of transgenes into either the chloroplast or mitochondrial genomes would reduce the likelihood of gene escape via pollen flow from crop fields into wild plant populations. In this paper we describe the adaptation of chloroplast simple sequence repeats (cpSSRs) for use in the Compositae. This work resulted in the identification of 12 loci that are variable across the family, seven of which were further shown to be highly polymorphic within sunflower (Helianthus annuus). We then used these markers, along with a novel mtDNA restriction fragment length polymorphism (RFLP), to investigate the mode of organellar inheritance in a series of experimental crosses designed to mimic the initial stages of crop-wild hybridization in sunflower. Although we cannot rule out the possibility of extremely rare paternal transmission, our results provide the best evidence to date of strict maternal organellar inheritance in sunflower, suggesting that organellar gene containment may be a viable strategy in sunflower. Moreover, the portability of these markers suggests that they will provide a ready source of cpDNA polymorphisms for use in evolutionary studies across the Compositae.

  8. INVESTIGATION ON THE EFFECT OF SOME PLANT GROWTH REGULATORS ON SUNFLOWER ( HELIANTHUS ANNUUS L.

    Directory of Open Access Journals (Sweden)

    Nurettin Tahsin

    2006-07-01

    Full Text Available With a view to establish the effect of some plant growth regulators on sunfl ower (Helianthus annuus L. production and oil content was made an experiment. The investigation was made on Bulgarian sunfl ower hybrid Super Start, treated during pinhead and fl owering stages. The effect of the tested plant growth regulators on the quantity of yield and some structural elements (sunfl ower heads number, seeds number, seeds mass, mass/ 1000 seeds, oil content % and oil yield kg/da was reported in the process of investigation. The effect grade of growth regulators is fi xed due to non-treated control. By the dispersal analysis method it is made mathematics processing of the values of received data. The investigation showed that there is not mathematically proved difference between the seed yield kg/da and oil content l/da in pinhead period by the use of plant growth regulators - ‘‘31’’ (1cm3/l water and ‘’Agat 25 EK’’ (2.5 g/ da. In the fl owering period when treated with the same plant growth regulators seed yield is 15.3 % increased and the oil content -18.6 % (with “31’’ and 16.4 % (with’’Agat 25 EK’’.

  9. Estimation of mating system parameters in an evolving gynodioecous population of cultivated sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Roumet, M; Ostrowski, M-F; David, J; Tollon, C; Muller, M-H

    2012-04-01

    Cultivated plants have been molded by human-induced selection, including manipulations of the mating system in the twentieth century. How these manipulations have affected realized parameters of the mating system in freely evolving cultivated populations is of interest for optimizing the management of breeding populations, predicting the fate of escaped populations and providing material for experimental evolution studies. To produce modern varieties of sunflower (Helianthus annuus L.), self-incompatibility has been broken, recurrent generations of selfing have been performed and male sterility has been introduced. Populations deriving from hybrid-F1 varieties are gynodioecious because of the segregation of a nuclear restorer of male fertility. Using both phenotypic and genotypic data at 11 microsatellite loci, we analyzed the consanguinity status of plants of the first three generations of such a population and estimated parameters related to the mating system. We showed that the resource reallocation to seed in male-sterile individuals was not significant, that inbreeding depression on seed production averaged 15-20% and that cultivated sunflower had acquired a mixed-mating system, with ∼50% of selfing among the hermaphrodites. According to theoretical models, the female advantage and the inbreeding depression at the seed production stage were too low to allow the persistence of male sterility. We discuss our methods of parameter estimation and the potential of such study system in evolutionary biology.

  10. Phomopsis Stem Canker: A Reemerging Threat to Sunflower (Helianthus annuus) in the United States.

    Science.gov (United States)

    Mathew, Febina M; Alananbeh, Kholoud M; Jordahl, James G; Meyer, Scott M; Castlebury, Lisa A; Gulya, Thomas J; Markell, Samuel G

    2015-07-01

    Phomopsis stem canker causes yield reductions on sunflower (Helianthus annuus L.) on several continents, including Australia, Europe, and North America. In the United States, Phomopsis stem canker incidence has increased 16-fold in the Northern Great Plains between 2001 and 2012. Although Diaporthe helianthi was assumed to be the sole causal agent in the United States, a newly described species, D. gulyae, was found to be the primary cause of Phomopsis stem canker in Australia. To determine the identity of Diaporthe spp. causing Phomopsis stem canker in the Northern Great Plains, 275 infected stems were collected between 2010 and 2012. Phylogenetic analyses of sequences of the ribosomal DNA internal transcribed spacer region, elongation factor subunit 1-α, and actin gene regions of representative isolates, in comparison with those of type specimens, confirmed two species (D. helianthi and D. gulyae) in the United States. Differences in aggressiveness between the two species were determined using the stem-wound method in the greenhouse; overall, D. helianthi and D. gulyae did not vary significantly (P≤0.05) in their aggressiveness at 10 and 14 days after inoculation. These findings indicate that both Diaporthe spp. have emerged as sunflower pathogens in the United States, and have implications on the management of this disease.

  11. Land use and wind direction drive hybridization between cultivated poplar and native species in a Mediterranean floodplain environment.

    Science.gov (United States)

    Paffetti, Donatella; Travaglini, Davide; Labriola, Mariaceleste; Buonamici, Anna; Bottalico, Francesca; Materassi, Alessandro; Fasano, Gianni; Nocentini, Susanna; Vettori, Cristina

    2018-01-01

    Deforestation and intensive land use management with plantations of fast-growing tree species, like Populus spp., may endanger native trees not only by eliminating or reducing their habitats, but also by diminishing their species integrity via hybridization and introgression. The genus Populus has persistent natural hybrids because clonal and sexual reproduction is common. The objective of this study was to assess the effect of land use management of poplar plantations on the spatial genetic structure and species composition in poplar stands. Specifically, we studied the potential breeding between natural and cultivated poplar populations in the Mediterranean environment to gain insight into spontaneous hybridization events between exotic and native poplars; we also used a GIS-based model to evaluate the potential threats related to an intensive land use management. Two study areas, both near to poplar plantations (P.×euramericana), were designated in the native mixed stands of P. alba, P. nigra and P.×canescens within protected areas. We found that the spatial genetic structure differed between the two stands and their differences depended on their environmental features. We detected a hybridization event with P.×canescens that was made possible by the synchrony of flowering between the poplar plantation and P.×canescens and facilitated by the wind intensity and direction favoring the spread of pollen. Taken together, our results indicate that natural and artificial barriers are crucial to mitigate the threats, and so they should be explicitly considered in land use planning. For example, our results suggest the importance of conserving rows of trees and shrubs along rivers and in agricultural landscapes. In sum, it is necessary to understand, evaluate, and monitor the spread of exotic species and genetic material to ensure effective land use management and mitigation of their impact on native tree populations. Copyright © 2017 Elsevier B.V. All rights

  12. Hybrid approaches for multiple-species stochastic reaction–diffusion models

    Energy Technology Data Exchange (ETDEWEB)

    Spill, Fabian, E-mail: fspill@bu.edu [Department of Biomedical Engineering, Boston University, 44 Cummington Street, Boston, MA 02215 (United States); Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Guerrero, Pilar [Department of Mathematics, University College London, Gower Street, London WC1E 6BT (United Kingdom); Alarcon, Tomas [Centre de Recerca Matematica, Campus de Bellaterra, Edifici C, 08193 Bellaterra (Barcelona) (Spain); Departament de Matemàtiques, Universitat Atonòma de Barcelona, 08193 Bellaterra (Barcelona) (Spain); Maini, Philip K. [Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Oxford OX2 6GG (United Kingdom); Byrne, Helen [Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Oxford OX2 6GG (United Kingdom); Computational Biology Group, Department of Computer Science, University of Oxford, Oxford OX1 3QD (United Kingdom)

    2015-10-15

    Reaction–diffusion models are used to describe systems in fields as diverse as physics, chemistry, ecology and biology. The fundamental quantities in such models are individual entities such as atoms and molecules, bacteria, cells or animals, which move and/or react in a stochastic manner. If the number of entities is large, accounting for each individual is inefficient, and often partial differential equation (PDE) models are used in which the stochastic behaviour of individuals is replaced by a description of the averaged, or mean behaviour of the system. In some situations the number of individuals is large in certain regions and small in others. In such cases, a stochastic model may be inefficient in one region, and a PDE model inaccurate in another. To overcome this problem, we develop a scheme which couples a stochastic reaction–diffusion system in one part of the domain with its mean field analogue, i.e. a discretised PDE model, in the other part of the domain. The interface in between the two domains occupies exactly one lattice site and is chosen such that the mean field description is still accurate there. In this way errors due to the flux between the domains are small. Our scheme can account for multiple dynamic interfaces separating multiple stochastic and deterministic domains, and the coupling between the domains conserves the total number of particles. The method preserves stochastic features such as extinction not observable in the mean field description, and is significantly faster to simulate on a computer than the pure stochastic model. - Highlights: • A novel hybrid stochastic/deterministic reaction–diffusion simulation method is given. • Can massively speed up stochastic simulations while preserving stochastic effects. • Can handle multiple reacting species. • Can handle moving boundaries.

  13. Interspecific hybridization of Vigna radiata x 13 wild Vigna species for developing MYMV donar

    Directory of Open Access Journals (Sweden)

    M. Pandiyan , N.Senthil, N. Ramamoorthi, AR.Muthiah, N.Tomooka V.Duncan and T.Jayaraj

    2010-07-01

    Full Text Available Mungbean (Vigna radiata (L. Wilczek is having a desirable characters like short duration, high protein, less anti nutritionalfactors, nitrogen fixing capacity, suitable for inter cropping, making many kinds of foods for higher human consumption andcosmetics products and some of the undesirable characters like low yield, low test weight.The aim of the study is to checkcrossabil;ity of Vigna radiata with all wild Vigna species and to create variability through wide hybridization and to developsuperior segregants for yield component coupled with pest and disease resistance. The interspecific crosses were attemptedwith thirteen wild relatives of mungbean (V. radiata were employed with V. radiata as male parent. The highest pod set of25 and crossability of 21.92 per cent was recorded by the cross V. radiata x V. radiata var. sublobata and lowest pod set of2.0 per cent recorded by the cross V. radiata x V. dalzelliana in the direct cross combinations. The highest pollengermination 69.72 per cent was recorded by V. radiata x V. radiata var. sublobata. The estimates of pollen fertility wassufficient enough to recover F2 segregants in all the crosses combination.For all the traits in majority of the crosses, In the F2generation the skewness was positive indicating that predominance of dominant alleles. Among the direct crosses V. radiatax V. mungo var. silvestris exhibited highest value for four characters viz., number of clusters per branch, number of clustersper plant, number of pods per plant and single plant yield. The cross V. umbellata x V. radiata showed better performancefor the characters viz., number of branches and number of clusters in reciprocal direction In advanced generation of Vignaradiata x Vigna umbellata cross combination has expressed virus resistance for nine seasons. The same line was tested byagro inoculation for confirmation of resistance and was resulted found effective resistance. This line can be used MYMVdonar. Conclusion of

  14. Assessing the putative roles of X-autosome and X-Y interactions in hybrid male sterility of the Drosophila bipectinata species complex.

    Science.gov (United States)

    Mishra, Paras Kumar; Singh, Bashisth Narayan

    2007-07-01

    Interspecific F1 hybrid males of the Drosophila bipectinata species complex are sterile, while females are fertile, following Haldane's rule. A backcross scheme involving a single recessive visible marker on the X chromosome has been used to assess the putative roles of X-autosome and X-Y interactions in hybrid male sterility in the D. bipectinata species complex. The results suggest that X-Y interactions are playing the major role in hybrid male sterility in the crosses D. bipectinata x D. parabipectinata and D. bipectinata x D. pseudoananassae, while X-autosome interactions are largely involved in hybrid male sterility in the crosses D. malerkotliana x D. bipectinata and D. malerkotliana x D. parabipectinata. However, by using this single marker it is not possible to rule out the involvement of autosome-autosome interactions in hybrid male sterility. These findings also lend further support to the phylogenetic relationships among 4 species of the D. bipectinata complex.

  15. Crude palm oil from interspecific hybrid Elaeis oleifera×Elaeis guineensis: fatty acid regiodistribution and molecular species of glycerides.

    Science.gov (United States)

    Mozzon, Massimo; Pacetti, Deborah; Lucci, Paolo; Balzano, Michele; Frega, Natale Giuseppe

    2013-11-01

    The composition and structure of triacylglycerols (TAGs) and partial glycerides of crude palm oil obtained from interspecific hybrid Elaeis oleifera×Elaeis guineensis, grown in Colombia, were fully characterised and compared to data obtained by analysing crude African palm oil. Hybridisation appears to substantially modify the biosynthesis of fatty acids (FAs) rather than their assembly in TAGs. In fact, total FAs analysis showed significant differences between these two types of oil, with hybrid palm oil having a higher percentage of oleic acid (54.6 ± 1.0 vs 41.4 ± 0.3), together with a lower saturated fatty acid content (33.5 ± 0.5 vs 47.3 ± 0.1), while the percentage of essential fatty acid, linoleic acid, does not undergo significant changes. Furthermore, 34 TAG types were identified, with no qualitative differences between African and E. guineensis×E. oleifera hybrid palm oil samples. Short and medium chain FAs (8:0, 10:0, 12:0, 14:0) were utilised, together, to build a restricted number of TAG molecular species. Oil samples from the E. guineensis×E. oleifera hybrid showed higher contents of monosaturated TAGs (47.5-51.0% vs 36.7-37.1%) and triunsaturated TAGs (15.5-15.6% vs 5.2-5.4%). The sn-2 position of TAGs in hybrid palm oil was shown to be predominantly esterified with oleic acid (64.7-66.0 mol% vs 55.1-58.2 mol% in African palm oil) with only 10-15% of total palmitic acid and 6-20% of stearic acid acylated in the secondary position. The total amount of diacylglycerols (DAGs) was in agreement with the values of free acidity; DAG types found were in agreement with the representativeness of different TAG species. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Effects of nitrogen and plant density on dwarf sunflower hybrids

    OpenAIRE

    Süzer S.

    2010-01-01

    This research was carried out to determine the seed yield and some yield components of two dwarf hybrids as compared to one standard-height sunflower hybrid (Helianthus annuus L.) at different nitrogen rates and planting densities. The study was carried out under natural rainfed conditions at the Thrace Agricultural Research Institute in Edirne-Turkey between 1999 and 2001. The experiments were set up in split-split plots in a randomized complete block desi...

  17. Genome Size Variation in Central European Species of Cirsium (Compositae) and their Natural Hybrids

    OpenAIRE

    Bureš, Petr; Wang, Yi-Feng; Horová, Lucie; Suda, Jan

    2004-01-01

    • Background and Aims Nuclear DNA amounts of 12 diploid and one tetraploid taxa and 12 natural interspecific hybrids of Cirsium from 102 populations in the Czech Republic, Austria, Slovakia and Hungary were estimated.

  18. Travelling in time with networks: Revealing present day hybridization versus ancestral polymorphism between two species of brown algae, Fucus vesiculosus and F. spiralis

    Directory of Open Access Journals (Sweden)

    Pearson Gareth A

    2011-01-01

    Full Text Available Abstract Background Hybridization or divergence between sympatric sister species provides a natural laboratory to study speciation processes. The shared polymorphism in sister species may either be ancestral or derive from hybridization, and the accuracy of analytic methods used thus far to derive convincing evidence for the occurrence of present day hybridization is largely debated. Results Here we propose the application of network analysis to test for the occurrence of present day hybridization between the two species of brown algae Fucus spiralis and F. vesiculosus. Individual-centered networks were analyzed on the basis of microsatellite genotypes from North Africa to the Pacific American coast, through the North Atlantic. Two genetic distances integrating different time steps were used, the Rozenfeld (RD; based on alleles divergence and the Shared Allele (SAD; based on alleles identity distances. A diagnostic level of genotype divergence and clustering of individuals from each species was obtained through RD while screening for exchanges through putative hybridization was facilitated using SAD. Intermediate individuals linking both clusters on the RD network were those sampled at the limits of the sympatric zone in Northwest Iberia. Conclusion These results suggesting rare hybridization were confirmed by simulation of hybrids and F2 with directed backcrosses. Comparison with the Bayesian method STRUCTURE confirmed the usefulness of both approaches and emphasized the reliability of network analysis to unravel and study hybridization

  19. Travelling in time with networks: Revealing present day hybridization versus ancestral polymorphism between two species of brown algae, Fucus vesiculosus and F. spiralis.

    Science.gov (United States)

    Moalic, Yann; Arnaud-Haond, Sophie; Perrin, Cécile; Pearson, Gareth A; Serrao, Ester A

    2011-01-31

    Hybridization or divergence between sympatric sister species provides a natural laboratory to study speciation processes. The shared polymorphism in sister species may either be ancestral or derive from hybridization, and the accuracy of analytic methods used thus far to derive convincing evidence for the occurrence of present day hybridization is largely debated. Here we propose the application of network analysis to test for the occurrence of present day hybridization between the two species of brown algae Fucus spiralis and F. vesiculosus. Individual-centered networks were analyzed on the basis of microsatellite genotypes from North Africa to the Pacific American coast, through the North Atlantic. Two genetic distances integrating different time steps were used, the Rozenfeld (RD; based on alleles divergence) and the Shared Allele (SAD; based on alleles identity) distances. A diagnostic level of genotype divergence and clustering of individuals from each species was obtained through RD while screening for exchanges through putative hybridization was facilitated using SAD. Intermediate individuals linking both clusters on the RD network were those sampled at the limits of the sympatric zone in Northwest Iberia. These results suggesting rare hybridization were confirmed by simulation of hybrids and F2 with directed backcrosses. Comparison with the Bayesian method STRUCTURE confirmed the usefulness of both approaches and emphasized the reliability of network analysis to unravel and study hybridization.

  20. New hybrids between Saccharomyces sensu stricto yeast species found among wine and cider production strains.

    Science.gov (United States)

    Masneuf, I; Hansen, J; Groth, C; Piskur, J; Dubourdieu, D

    1998-10-01

    Two yeast isolates, a wine-making yeast first identified as a Mel+ strain (ex. S. uvarum) and a cider-making yeast, were characterized for their nuclear and mitochondrial genomes. Electrophoretic karyotyping analyses, restriction fragment length polymorphism maps of PCR-amplified MET2 gene fragments, and the sequence analysis of a part of the two MET2 gene alleles found support the notion that these two strains constitute hybrids between Saccharomyces cerevisiae and Saccharomyces bayanus. The two hybrid strains had completely different restriction patterns of mitochondrial DNA as well as different sequences of the OLI1 gene. The sequence of the OLI1 gene from the wine hybrid strain appeared to be the same as that of the S. cerevisiae gene, whereas the OLI1 gene of the cider hybrid strain is equally divergent from both putative parents, S. bayanus and S. cerevisiae. Some fermentative properties were also examined, and one phenotype was found to reflect the hybrid nature of these two strains. The origin and nature of such hybridization events are discussed.

  1. Asymmetry of frontal bristles and postocular setae in species and hybrids of the Anastrepha fraterculus complex (Diptera, Tephritidae

    Directory of Open Access Journals (Sweden)

    João Maria G.A. Souza

    2007-01-01

    Full Text Available Asymmetry of the frontal bristles and postocular setae was studied in samples from natural populations and laboratory colonies of Anastrepha sp. 1 aff. fraterculus, of A. sp. 2 aff. fraterculus, and in F1 hybrids obtained from laboratory reciprocal crosses. Natural populations were sampled in a zone of sympatry and in two geographically distant regions with different climatic conditions. Asymmetry was scored as the differences between the number of bristles and of setae on the right and left sides of the head, males and females analyzed independently. The two traits exhibited variability according to the model of fluctuating asymmetry (FA. No significant differences among samples were found in the FA of frontal bristles. A significant FA was observed for the postocular setae of A. sp. 1 males from a southern population (Vacaria, RS as compared to the asymmetry exhibited by males and females of some other samples. No significant differences in FA were observed among the interspecific hybrids and the laboratory samples of both parental species. The higher FA found in the males from Vacaria was attributed to climatic conditions prevailing in that region. The absence of a higher FA in hybrids may be related to the relatively recent evolutionary history of the two species.

  2. Solid phase fermentation of Helianthus tuberosus for ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Baerwald, G.; Hamad, S.H.

    1989-01-01

    The direct fermentation of pure inulin and hammer mill crushed Helianthus tuberosus tubers (topinambur, Jerusalem artichoke) was studied using two heat-tolerant yeasts, namely Kluyveromyces marxianus and Candida kefyr. A Saccharomyces cerevisiae was included in the study so as to compare the yields of these two yeasts with that of a commercial distiller's yeast. The inulin fermentation was carried out in an 18-L bioreactor using the fed-batch and the batch-fermentation methods. The final ethanol concentration was 6.1% (L/L) which represents 82% of the theoretical yield. Commercial scale experiments with hammer mill crushed tubers gave yields lower than those found in the laboratory: 69% of the theoretical yield for direct fermentation without enzyme addition, and about 91% when cellolytic enzymes were added.

  3. Genomic insights into hybridization in a localized region of sympatr y between pewee sister species (Contopus sordidulus × C. virens) and their chromosomal patterns of differentiation

    Institute of Scientific and Technical Information of China (English)

    Joseph D Manthey; and Mark B Robbins

    2016-01-01

    Background: The Great Plains of the United States includes a large number of hybrid and contact zones between bird species. The amount of gene lfow between sister species in these zones ranges from very rare hybridization events to widespread and prevalent introgression. Some of these avian systems have been studied extensively, while others have been indeterminate of whether hybridization exists in areas of sympatry. Using genomic-level approaches allows investigation of genomic patterns of hybridization and gene lfow between species—or lack thereof. Methods: We investigated a narrow zone of sympatry in Nebraska, USA between pewee species (Contopus sordidu-lus and C. virens), for which no hybridization has been conifrmed. We used thousands of single nucleotide polymor-phisms to identify potential hybridization and investigate genomic patterns of differentiation between these two species. Results: We found evidence of multiple hybrid individuals in the contact zone. Little genomic variation was ifxed between species, but a large proportion had differentiated allele frequencies between species. There was a positive relationship between genetic differentiation and chromosome size. Conclusions: We provided the ifrst conclusive evidence of hybridization between C. sordidulus and C. virens, in a region where secondary contact likely occurred due to human disturbance and habitat modiifcation. The genomic patterns of differentiation affrm that these species split in the relatively recent past. Finally, the relationship of chro-mosome size and genetic differentiation may have resulted from differential rates of chromosomal recombination in songbirds and genetic differentiation between species largely due to genetic drift (possibly in concert with selection).

  4. Genetic evidence of hybridization between the endangered native species Iguana delicatissima and the invasive Iguana iguana (Reptilia, Iguanidae) in the Lesser Antilles: management Implications

    OpenAIRE

    Barbara Vuillaume; Victorien Valette; Olivier Lepais; Frédéric Grandjean; Michel Breuil

    2015-01-01

    The worldwide increase of hybridization in different groups is thought to have become more important with the loss of isolating barriers and the introduction of invasive species. This phenomenon could result in the extinction of endemic species. This study aims at investigating the hybridization dynamics between the endemic and threatened Lesser Antillean iguana (Iguana delicatissima) and the invasive common green iguana (Iguana iguana) in the Lesser Antilles, as well as assessing the impact ...

  5. Enhanced drought-tolerance in the homoploid hybrid species Pinus densata: implication for its habitat divergence from two progenitors.

    Science.gov (United States)

    Ma, Fei; Zhao, Changming; Milne, Richard; Ji, Mingfei; Chen, Litong; Liu, Jianquan

    2010-01-01

    The homoploid hybrid species Pinus densata is restricted to alpine habitats that exceed the altitude range of its two parental species, Pinus tabulaeformis and Pinus yunnanensis. Alpine habitats usually generate cold-induced water stress in plants. To understand the ecological differentiation between these three species, we examined their physiological responses to drought stress. Potted seedlings of three species were subjected to low, mild, moderate and severe water stress in an automatic-controlled glasshouse. Fifteen indicators of fitness were measured for each species in each treatment, and most of these decreased as drought increased. Pinus densata exhibited higher fitness than both parental species in terms of total dry mass production (TDM) and long-term water use efficiency (WUE(L)) across all treatments; several other ecophysiological traits were also extreme but not across every treatment, and not always in the highest stress treatment. These results indicate that extreme characters that have become well fixed in P. densata, confer a faster seedling growth rate and more efficient water use, which in turn should confer increased drought tolerance. These traits of P. densata likely promoted its ecological separation from its parental species and facilitated its successful colonization and establishment in high-altitude habitats.

  6. Fusarium foetens, a new species pathogenic to begonia elatior hybrids (Begonia x hiemalis) and the sister taxon of the Fusarium oxysporum species complex.

    Science.gov (United States)

    Schroers, H-J; Baayen, R P; Meffert, J P; de Gruyter, J; Hooftman, M; O'Donnell, K

    2004-01-01

    A new disease recently was discovered in begonia elatior hybrid (Begonia × hiemalis) nurseries in The Netherlands. Diseased plants showed a combination of basal rot, vein yellowing and wilting and the base of collapsing plants was covered by unusually large masses of Fusarium macroconidia. A species of Fusarium was isolated consistently from the discolored veins of leaves and stems. It differed morphologically from F. begoniae, a known agent of begonia flower, leaf and stem blight. The Fusarium species resembled members of the F. oxysporum species complex in producing short monophialides on the aerial mycelium and abundant chlamydospores. Other phenotypic characters such as polyphialides formed occasionally in at least some strains, relatively long monophialides intermingled with the short monophialides formed on the aerial mycelium, distinct sporodochial conidiomata, and distinct pungent colony odor distinguished it from the F. oxysporum species complex. Phylogenetic analyses of partial sequences of the mitochondrial small subunit of the ribosomal DNA (mtSSU rDNA), nuclear translation elongation factor 1α (EF-1α) and β-tubulin gene exons and introns indicate that the Fusarium species represents a sister group of the F. oxysporum species complex. Begonia × hiemalis cultivars Bazan, Bellona and Netja Dark proved to be highly susceptible to the new species. Inoculated plants developed tracheomycosis within 4 wk, and most died within 8 wk. The new taxon was not pathogenic to Euphorbia pulcherrima, Impatiens walleriana and Saintpaulia ionantha that commonly are grown in nurseries along with B. × hiemalis. Inoculated plants of Cyclamen persicum did not develop the disease but had discolored vessels from which the inoculated fungus was isolated. Given that the newly discovered begonia pathogen is distinct in pathogenicity, morphology and phylogeny from other fusaria, it is described here as a new species, Fusarium foetens.

  7. New hybrids between Saccharomyces sensu stricto yeast species found among wine and cider production strains

    DEFF Research Database (Denmark)

    Masneuf, I; Hansen, J.; Groth, C

    1998-01-01

    Two yeast isolates, a wine-making yeast first identified as a Mel(+) strain (ex. S. uvarum) and a cider-making yeast, were characterized for their nuclear and mitochondrial genomes, Electrophoretic karyotyping analyses, restriction fragment length polymorphism maps of PCR-amplified MET2 gene...... as different sequences of the OLI1 gene. The sequence of the OLI1 gene from the wine hybrid strain appeared to be the same as that of the S. cerevisiae gene, whereas the OLI1 gene of the cider hybrid strain its equally divergent from both putative parents, S. bayanus and S, cerevisiae, Some fermentative...

  8. Cr localization and speciation in roots of chromate fed Helianthus annuus L. seedlings using synchrotron techniques.

    Science.gov (United States)

    de la Rosa, Guadalupe; Castillo-Michel, Hiram; Cruz-Jiménez, Gustavo; Bernal-Alvarado, Jesús; Córdova-Fraga, Teodoro; López-Moreno, Laura; Cotte, Marine

    2014-01-01

    In order to gain knowledge on the potential use of Helianthus annuus L. for the remediation of Cr(VI) polluted waters, hydroponics experiments were set up to determine Cr uptake and tolerance in different Cr(VI)-sulfate conditions, and Cr biotransformations. Results indicated that Cr(VI) promoted seed germination, and plant tolerance was higher at younger plant stages. Cr uptake was dependent on sulfate concentrations. The highest Cr levels in roots and shoots (13,700 and 2,500 mg kg(-1) dry weight (DW), respectively) were obtained in 1 mM sulfate. The lowest Cr uptake in roots (10,600 mg kg(-1) DW) was observed in seedlings treated with no sulfate. In shoots, Cr concentration was of 1,500 mg kg(-1)DW for the 1 mM sulfate treatment, indicating a different level of interaction between chromate and sulfate in both tissues. For the first time, using micro X-ray florescence (muXRF), we demonstrated Cr reaches the root stele and is located in the walls of xylem vessels. Bulk and micro X-ray Absorption Near-Edge Structure (muXANES) results showed that Cr in the roots is mostly in the form of Cr(III) phosphate (80%), with the remainder complexed to organic acids. Our results suggest this plant species may serve for Cr(VI) rhizofiltration purposes.

  9. Evaluation of the courtship and of the hybrid male sterility among Drosophila buzzatii cluster species (Diptera, Drosophilidae

    Directory of Open Access Journals (Sweden)

    MACHADO L. P. de B.

    2002-01-01

    Full Text Available In the Drosophila repleta group the establishment of subgroups and complexes made on the basis of morphological and cytological evidences is supported by tests of reproductive isolation. Among species in the repleta group, the buzzatii cluster, due to its polymorphism and polytipism, is an excellent material for ecological and speciation studies. Some interspecific crosses involving Drosophila seriema, Drosophila sp. B, D. koepferae and D. buzzatii strains were completely sterile while others involving strains from these species produced F1 hybrids that did not yield F2. In the present work, data on courtship duration and copula occurrence obtained in the analysis of flies from parental sterile crosses and on spermatozoon mobility observed in F1 hybrids that did not yield F2 are presented. Copula did not occur during one hour of observation and the spermatozoon also did not show mobility at any of the analyzed stages (3, 7, 9 and 10 days old. There was a high variation in courtship average duration and in the percentage of males that courted the females. The reproductive isolation mechanisms indicated by these observations were pre and post-zygotic, as supported by the absence of copula and male sterility. Data obtained also showed the occurrence of different degrees of reproductive compatibility among the strains classified as the same species but from distinct geographic localities.

  10. A potential species-specific molecular marker suggests interspecific hybridization between sibling species Littorina arcana and L. saxatilis (Mollusca, Caenogastropoda) in natural populations.

    Science.gov (United States)

    Mikhailova, Natalia A; Gracheva, Yulia A; Backeljau, Thierry; Granovitch, Andrey I

    2009-12-01

    Three sister species of rough periwinkles, viz. Littorina saxatilis (Olivi 1792), L. arcana (Hannaford Ellis 1978) and L. compressa (Jeffreys 1865) from the Barents Sea (Russia), the White Sea (Russia) and the Norwegian Sea (Norway) were studied. The identification of two sibling species L. saxatilis and L. arcana is often difficult as both species have extremely similar shell morphology and reproductive systems. Only mature females can be unambiguously distinguished, with a jelly gland present in female L. arcana, but which is replaced by a brood pouch containing developing embryos in L. saxatilis. No clear-cut diagnostic features have been found to discriminate between males or juveniles of the two species. The very first diagnostic DNA marker (DNA fragment A2.8, 271 bp length) for L. arcana and L. saxatilis separation was developed. The marker was derived from apparently species-specific L. arcana DNA fragments obtained via Random Amplified Polymorphic DNA (RAPD) analysis. This fragment was cloned and sequenced, whereupon specific primers were designed and the amplification was surveyed in a large number of morphologically well-identified females of both species. Subsequently, the specific DNA marker was used for the identification of male L. arcana and partners in copulating pairs. In this way, we obtained evidence of possible interspecific hybridization between the sibling species L. arcana and L. saxatilis living in sympatry in natural populations: the presence of A2.8 fragment in 12% of morphologically well identified L. saxatilis females and its absence in 14% of morphologically well identified L. arcana females. The A2.8 fragment never amplified in L. saxatilis from sites without L. arcana. The A2.8 fragment did not amplify in L. compressa, not even in microsympatric populations, and we did not observe interspecific copulations between L. arcana and L. compressa.

  11. The influence of hybridization on epidermal properties of birch species and the consequences for palaeoclimatic interpretations

    NARCIS (Netherlands)

    Wagner, F.; Kürschner, W.M.; Neuvonen, S.; Visscher, H.

    2000-01-01

    The Fennoscandian birch population primarily consists of Betula nana, B. pendula and B. pubescens ssp. czerepanovii, the Mountain birch. Frequent hybridization between the Mountain birch and B. nana generates a wide range of genotypic and phenotypic plasticity in the subarctic birch zone of Fennosca

  12. Natural infection of several Coffea species and hybrids and Psilanthus ebracteolatus by the coffee ringspot virus (CoRSV

    Directory of Open Access Journals (Sweden)

    Elliot Watanabe Kitajima

    2011-08-01

    Full Text Available Coffee ringspot is a minor coffee disease caused by the nuclear type of Brevipalpus mite-transmitted virus, Coffee ringspot virus (CoRSV. Recently outbreaks of the disease in some growing regions of the state of Minas Gerais, Brazil, were registered with qualitative and quantitative yield losses. Coffea arabica was the only species registered as natural host. A survey was made on a germplasm collection of Coffea and related species kept at the Centro de Café "Alcides Carvalho", Instituto Agronômico, Campinas, state of São Paulo (SP, Brazil, to assess natural susceptibility of Coffee species, other than C. arabica and some interspecific hybrids of Coffea as well as other non-Coffea plant species to the Coffee ringspot virus (CoRSV. The following plants were found with ringspot symptoms on their leaves and/or fruits besides C. arabica L.: C. kapakata (IAC 4511, C. dewevrei cv. Excelsa, C. canephora cv. Robusta, hybrid derivative of the C. arabica × C. racemosa (IAC1195-5-6-2, C. arabica × C. dewerei (Piatã IAC 387, Híbrido de Timor CIFC 832/1 (derivative from a natural crossing between C. arabica × C. canephora and C. racemosa. Also Psilanthus ebracteolatus, a species close to the genus Coffee was also found with ringspot lesions on their leaves. All these plants were also found infested by Brevipalpus mites identified as B. phoenicis. Infection of these plants by CoRSV was confirmed by the observation of characteristic cytopathic effects in the tissues of the lesion and by RT-PCR using a pair of primer specific for CoRSV. Only with C. racemosa RT-PCR failed to amplify the CoRSV genome. The susceptibility of P. ebracteolatus to CoRSV adds new dimension regarding its controversial taxonomic position.

  13. Homoeologous chromosome pairing in the distant hybrid Alstroemeria aurea x A. inodora and the genome composition of its backcross derivatives determined by fluorescence in situ hybridization with species-specific probes.

    Science.gov (United States)

    Kamstra, S A; Ramanna, M S; de Jeu, M J; Kuipers, A G; Jacobsen, E

    1999-01-01

    A distant hybrid between two diploid species (2n = 2x = 16), Alstroemeria aurea and A. inodora, was investigated for homoeologous chromosome pairing, crossability with A. inodora and chromosome transmission to its BC1 offspring. Fluorescence in situ hybridization (FISH) with two species-specific probes, A001-I (A. aurea specific) and D32-13 (A. inodora specific), was used to analyse chromosome pairing in the hybrid and the genome constitution of its BC1 progeny plants. High frequencies of associated chromosomes were observed in both genotypes of the F1 hybrid, A1P2-2 and A1P4. In the former, both univalents and bivalents were found at metaphase I, whereas the latter plant also showed tri- and quadrivalents. Based on the hybridization sites of DNA probes on the chromosomes of both parental species, it was established that hybrid A1P4 contains a reciprocal translocation between the short arm of chromosome 1 and the long arm of chromosome 8 of A. inodora. Despite regular homoeologous chromosome pairing in 30% of the pollen mother cells, both hybrids were highly sterile. They were backcrossed reciprocally with one of the parental species, A. inodora. Two days after pollination, embryo rescue was applied and, eventually, six BC1 progeny plants were obtained. Among these, two were aneuploids (2n = 2x + 1 = 17) and four were triploids (2n = 3x = 24). The aneuploid plants had originated when the interspecific hybrid was used as a female parent, indicating that n eggs were functional in the hybrid. In addition, 2n gametes were also functional in the hybrid, resulting in the four triploid BC1 plants. Of these four plants, three had received 2n pollen grains from the hybrid and one a 2n egg. Using FISH, homoeologous crossing over between the chromosomes of the two parental species in the hybrid was clearly detected in all BC1 plants. The relevance of these results for the process of introgression and the origin of n and 2n gametes are discussed.

  14. Molecular cloning, phylogenetic analysis, and expression patterns of LATERAL SUPPRESSOR-LIKE and REGULATOR OF AXILLARY MERISTEM FORMATION-LIKE genes in sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Fambrini, Marco; Salvini, Mariangela; Pugliesi, Claudio

    2016-12-29

    The wild sunflower (Helianthus annuus) plants develop a highly branched form with numerous small flowering heads. The origin of a no branched sunflower, producing a single large head, has been a key event in the domestication process of this species. The interaction between hormonal factors and several genes organizes the initiation and outgrowth of axillary meristems (AMs). From sunflower, we have isolated two genes putatively involved in this process, LATERAL SUPPRESSOR (LS)-LIKE (Ha-LSL) and REGULATOR OF AXILLARY MERISTEM FORMATION (ROX)-LIKE (Ha-ROXL), encoding for a GRAS and a bHLH transcription factor (TF), respectively. Typical amino acid residues and phylogenetic analyses suggest that Ha-LSL and Ha-ROXL are the orthologs of the branching regulator LS and ROX/LAX1, involved in the growth habit of both dicot and monocot species. qRT-PCR analyses revealed a high accumulation of Ha-LSL transcripts in roots, vegetative shoots, and inflorescence shoots. By contrast, in internodal stems and young leaves, a lower amount of Ha-LSL transcripts was observed. A comparison of transcription patterns between Ha-LSL and Ha-ROXL revealed some analogies but also remarkable differences; in fact, the gene Ha-ROXL displayed a low expression level in all organs analyzed. In situ hybridization (ISH) analysis showed that Ha-ROXL transcription was strongly restricted to a small domain within the boundary zone separating the shoot apical meristem (SAM) and the leaf primordia and in restricted regions of the inflorescence meristem, beforehand the separation of floral bracts from disc flower primordia. These results suggested that Ha-ROXL may be involved to establish a cell niche for the initiation of AMs as well as flower primordia. The accumulation of Ha-LSL transcripts was not restricted to the boundary zones in vegetative and inflorescence shoots, but the mRNA activity was expanded in other cellular domains of primary shoot apical meristem as well as AMs. In addition, Ha

  15. Genetics and mapping of a novel downy mildew resistance gene, Pl18, introgressed from wild Helianthus argophyllus into cultivated sunflower (Helianthus annuus L.)

    Science.gov (United States)

    Sunflower downy mildew is considered to be the most destructive foliar disease that has spread to every major sunflower-growing country of the world, except Australia. A new dominant downy mildew resistance gene (Pl18) transferred from wild Helianthus argophyllus (PI 494573) into cultivated sunflowe...

  16. Identification and Characterization of VNI/VNII and Novel VNII/VNIV Hybrids and Impact of Hybridization on Virulence and Antifungal Susceptibility Within the C. neoformans/C. gattii Species Complex

    Science.gov (United States)

    Aminnejad, Mojgan; Cogliati, Massimo; Duan, Shuyao; Arabatzis, Michael; Tintelnot, Kathrin; Castañeda, Elizabeth; Lazéra, Marcia; Velegraki, Aristea; Ellis, David; Sorrell, Tania C.; Meyer, Wieland

    2016-01-01

    Cryptococcus neoformans and C. gattii are pathogenic basidiomycetous yeasts and the commonest cause of fungal infection of the central nervous system. Cryptococci are typically haploid but several inter-species, inter-varietal and intra-varietal hybrids have been reported. It has a bipolar mating system with sexual reproduction occurring normally between two individuals with opposite mating types, α and a. This study set out to characterize hybrid isolates within the C. neoformans/C. gattii species complex: seven unisexual mating intra-varietal VNI/VNII (αAAα) and six novel inter-varietal VNII/VNIV (aADα). The URA5-RFLP pattern for VNII/VNIV (aADα) differs from the VNIII (αADa) hybrids. Analysis of the allelic patterns of selected genes for AD hybrids showed 79% or more heterozygosis for the studied loci except for CBS132 (VNIII), which showed 50% of heterozygosity. MALDI-TOF MS was applied to hybrids belonging to different sero/mating type allelic patterns. All hybrid isolates were identified as belonging to the same hybrid group with identification scores ranging between 2.101 to 2.634. All hybrids were virulent when tested in the Galleria mellonella (wax moth) model, except for VNII/VNIV (aADα) hybrids. VNI/VGII hybrids were the most virulent hybrids. Hybrids recovered from larvae manifested a significant increase in capsule and total cell size and produced a low proportion (5–10%) of giant cells compared with the haploid control strains. All strains expressed the major virulence factors—capsule, melanin and phospholipase B—and grew well at 37°C. The minimal inhibitory concentration of nine drugs was measured by micro-broth dilution and compared with published data on haploid strains. MICs were similar amongst hybrids and haploid parental strains. This is the first study reporting natural same sex αAAα intra-varietal VNI/VNII hybrids and aADα inter-varietal VNII/VNIV hybrids. PMID:27764108

  17. [Application of somatic hybrids between dihaploids of potato Solanum tuberosum L. and wild diploid species from Mexico in breeding: generation and backcrossing of dihaploids of somatic hybrids].

    Science.gov (United States)

    Ermishin, A P; Makhan'ko, O V; Voronkova, E V

    2006-12-01

    The efficiency of an original approach to involvement of the valuable genetic pool of wild diploid potato species from Mexico is estimated. The essence of this method is in generation of dihaploids (2n = 2x = 24) of tetraploid somatic hybrids (2n = 4x = 48) followed by backcrossing with dihaploids of Solanum tuberosum. A haploid producer, S. phureja IvP35, was used to generate ten dihaploids of S. tuberosum + S. pinnatisectum, all of which crossed with fertile S. tuberosum dihaploids and developed plump viable seeds. This gives the possibility of an efficient introgression of the genes valuable for breeding from wild species to the bred plants at a diploid level, which has several advantages compared with the corresponding procedure at a tetraploid level. A part of the dihaploids produced was compatible (the pollen tubes reached the ovary) with diploid and tetraploid forms of S. pinnatisectum; however, no viable seeds were developed. The attempt to generate the dihaploids of S. tuberosum + S. bulbocastanum somatic hydrides using the haploid producer S. phureja IvP35 was unsuccessful.

  18. Hybrid origin and differentiation of two tetraploid Achillea species in East Asia: molecular, morphological and ecogeographical evidence.

    Science.gov (United States)

    Guo, Y-P; Vogl, C; Van Loo, M; Ehrendorfer, F

    2006-01-01

    Achillea (Asteraceae-Anthemideae) offers classical models for speciation by hybridization and polyploidy. Here, we test the suspected allotetraploid origin of two species, Achillea alpina and Achillea wilsoniana between phylogenetically distinct lineages in East Asia. A total of 421 AFLP bands from 169 individuals and 19 populations of five 2x- and two 4x-species were obtained. The data set was analysed with a newly developed model that accounts for polyploidy and assumes lack of recombination between the parental chromosome sets (i.e. disomic inheritance). A. alpina and A. wilsoniana then appear to be allotetraploids between Achillea acuminata-2x (sect. Ptarmica) and Achillea asiatica-2x (sect. Achillea). The two 4x-species share 44% and 48% of their AFLP bands with A. acuminata-2x, and 39% and 38% with A. asiatica-2x, respectively. Eight plastid haplotypes (A-H) were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses. A. alpina-4x and A. wilsoniana-4x share haplotype F only with A. asiatica-2x. This is consistent with the hybrid origin(s) involving the latter as the maternal ancestor. This result corroborates our previous DNA sequence data, where A. alpina-4x and A. wilsoniana-4x are also placed close to A. asiatica-2x. Morphology, ecology, and amplified fragment length polymorphism (AFLP) profiles of the two 2x-species are distinct, whereas the two 4x-species, grouped as A. alpina aggregate, form a nearly continuous link between them. Considering all evidence, this 4x-aggregate is regarded as the product of a hybridization between genetically distant 2x-ancestors limited to China and adjacent areas: one A. acuminata-like, and the other A. asiatica-like. The allopolyploid A. alpina agg. exhibits considerable morphological variation and ecological flexibility, and has expanded throughout eastern Asia and to northern North America, far beyond the ranges of their presumed 2x-ancestors.

  19. Testing for bias in a sentinel species: contaminants in free-ranging domestic, wild, and hybrid mink.

    Science.gov (United States)

    Bowman, Jeff; Kidd, Anne G; Martin, Pamela A; McDaniel, Tana V; Nituch, Larissa A; Schulte-Hostedde, Albrecht I

    2012-01-01

    Sentinel species are important tools for studies of biodiversity and environmental health. The American mink (Neovison vison) has long been considered a sentinel of environmental contamination, since the species is known to be sensitive to a number of common contaminants, including polychlorinated biphenyls (PCB) and mercury. Mink may not always satisfy an important criterion of sentinels however--that they are continuous residents of the environment being sampled. This is because domestic mink commonly escape from farms, and can be confused with wild mink in areas where mink ranching is prevalent, biasing estimates of environmental contamination taken from free-ranging mink samples. We tested for bias in a sample of free-ranging mink from Ontario, Canada, where both genetic ancestry (domestic, wild, and domestic-wild hybrid) and contaminant burdens (PCBs and mercury) were known. Of 133 mink sampled for both contaminants and genetic ancestry, 9% were determined to be domestic and 10.5% hybrid animals. We found that including domestic and hybrid mink in our analysis resulted in overestimating mean PCB burdens in wild mink by 27%, and underestimating mercury by 13%. We also investigated morphological methods to aid in excluding domestic mink from free-ranging mink samples and found that we had the highest classification success using skull size (condylobasal length), which was 15% and 12% greater in male and female domestic than wild mink, respectively. Given the potential use of mink as sentinels, and also the potential for bias, we recommend that researchers take steps to exclude domestic mink from free-ranging mink samples in studies of environmental health.

  20. Evolutionary relationships between the former species Saccharomyces uvarum and the hybrids Saccharomyces bayanus and Saccharomyces pastorianus; reinstatement of Saccharomyces uvarum (Beijerinck) as a distinct species.

    Science.gov (United States)

    Nguyen, Huu-Vang; Gaillardin, Claude

    2005-02-01

    Analysis of the nucleotide sequence of the GDH1 homologues from Saccharomyces bayanus strain CBS 380T and S. pastorianus strains showed that they share an almost identical sequence, SuGDH1*, which is a diverged form of the SuGDH1 from the type strain of the former species S. uvarum, considered as synonym of S. bayanus. SuGDH1* is close to but differs from SuGDH1 by the accumulation of a high number of neutral substitutions designated as Multiple Neutral Mutations Accumulation (MNMA). Further analysis carried out with three other markers, BAP2, HO and MET2 showed that they have also diverged from their S. uvarum counterparts by MNMA. S. bayanus CBS 380T is placed between S. uvarum and S. pastorianus sharing MET2, CDC91 sequences with the former and BAP2, GDH1, HO sequences with the latter. S. bayanus CBS 380T has been proposed to be a S. uvarum/S. cerevisiae hybrid and this proposal is confirmed by the presence in its genome a S. cerevisiae SUC4 gene. Strain S. bayanus CBS 380T, with a composite genome, is genetically isolated from strains of the former S. uvarum species, thus justifying the reinstatement of S. uvarum as a distinct species.

  1. Can arsenic-phytochelatin complex formation be used as an indicator for toxicity in Helianthus annuus?

    Science.gov (United States)

    Raab, Andrea; Ferreira, Katia; Meharg, Andrew A; Feldmann, Jörg

    2007-01-01

    The formation of arsenic-phytochelatin (As-PC) complexes is thought to be part of the plant detoxification strategy for arsenic. This work examines (i) the arsenic (As) concentration-dependent formation of As-PC complex formation and (ii) redistribution and metabolism of As after arrested As uptake in Helianthus annuus. HPLC with parallel ICP-MS/ES-MS detection was used to identify and quantify the species present in plant extracts exposed to arsenate (As(V)) (between 0 and 66.7 micromol As l-1 for 24 h). At As concentrations below the EC50 value for root growth (22 micromol As l-1) As uptake is exponential, but it is reduced at concentrations above. Translocation between root and shoot seemed to be limited to the uptake phase of arsenic. No redistribution of As between root and shoot was observed after arresting As exposure. The formation of As-PC complexes was concentration-dependent. The amount and number of As-PC complexes increased exponentially with concentration up to 13.7 micromol As l-1. As(III)-PC3 and GS-As(III)-PC2 complexes were the dominant species in all samples. The ratio of PC-bound As to unbound As increased up to 1.3 micromol As l-1 and decreased at higher concentrations. Methylation of inorganic As was only a minor pathway in H. annuus with about 1% As methylated over a 32 d period. The concentration dependence of As-PC complex formation, amount of unbound reduced and oxidized PC2, and the relative uptake rate showed that As starts to influence the cellular metabolism of H. annuus negatively at As concentrations well below the EC50 value determined by more traditional means. Generally, As-PC complexes and PC-synthesis rate seem to be the more sensitive parameters to be studied when As toxicity values are to be estimated.

  2. The sunflower (Helianthus annuus L.) genome reflects a recent history of biased accumulation of transposable elements.

    Science.gov (United States)

    Staton, S Evan; Bakken, Bradley H; Blackman, Benjamin K; Chapman, Mark A; Kane, Nolan C; Tang, Shunxue; Ungerer, Mark C; Knapp, Steven J; Rieseberg, Loren H; Burke, John M

    2012-10-01

    Aside from polyploidy, transposable elements are the major drivers of genome size increases in plants. Thus, understanding the diversity and evolutionary dynamics of transposable elements in sunflower (Helianthus annuus L.), especially given its large genome size (∼3.5 Gb) and the well-documented cases of amplification of certain transposons within the genus, is of considerable importance for understanding the evolutionary history of this emerging model species. By analyzing approximately 25% of the sunflower genome from random sequence reads and assembled bacterial artificial chromosome (BAC) clones, we show that it is composed of over 81% transposable elements, 77% of which are long terminal repeat (LTR) retrotransposons. Moreover, the LTR retrotransposon fraction in BAC clones harboring genes is disproportionately composed of chromodomain-containing Gypsy LTR retrotransposons ('chromoviruses'), and the majority of the intact chromoviruses contain tandem chromodomain duplications. We show that there is a bias in the efficacy of homologous recombination in removing LTR retrotransposon DNA, thereby providing insight into the mechanisms associated with transposable element (TE) composition in the sunflower genome. We also show that the vast majority of observed LTR retrotransposon insertions have likely occurred since the origin of this species, providing further evidence that biased LTR retrotransposon activity has played a major role in shaping the chromatin and DNA landscape of the sunflower genome. Although our findings on LTR retrotransposon age and structure could be influenced by the selection of the BAC clones analyzed, a global analysis of random sequence reads indicates that the evolutionary patterns described herein apply to the sunflower genome as a whole.

  3. Evolutionary analysis of the CACTA DNA-transposon Caspar across wheat species using sequence comparison and in situ hybridization.

    Science.gov (United States)

    Sergeeva, Ekaterina M; Salina, Elena A; Adonina, Irina G; Chalhoub, Boulos

    2010-07-01

    Mobile elements constitute a considerable part of the eukaryotic genome. This work is focused on the distribution and evolution of DNA-transposons in the genomes of diploid and allopolyploid Triticeae species and their role in the formation of functionally important chromosomal subtelomeric regions. The Caspar family is among the most abundant of CACTA DNA-transposons in Triticeae. To study the evolution of Caspar-like elements in Triticeae genomes, we analyzed their sequences and distribution in chromosomes by in situ hybridization. In total, 46 Caspar-like elements from the wheat and barley Caspar, Clifford, and Donald families were analyzed after being extracted from databases using the transposase consensus sequence. Sequence alignment and subsequent phylogenetic analyses revealed that the transposase DNA sequences formed three major distinct groups: (1) Clifford, (2) Caspar_Triticinae, and (3) Caspar_Hordeinae. Additionally, in situ hybridization demonstrated that Caspar_Triticinae transposons are predominantly compartmentalized in the subtelomeric chromosomal regions of wheat and its progenitors. Analysis of data suggested that compartmentalization in the subtelomeric chromosomal region was a characteristic feature of all the main groups of Caspar-like elements. Furthermore, a dot plot analysis of the terminal repeats demonstrated that the divergence of these repeats strictly correlated with the divergence of Caspar coding sequences. A clear distinction in the Caspar DNA sequences among the species Triticum/Aegilops (Caspar_Triticinae), Hordeum (Caspar_Hordeinae), and different distributions in individual hexaploid wheat genomes (A/B and D) suggest an independent proliferation of these elements in wheat (or its progenitors) and barley genomes. Thus, Caspar-like transposons can significantly contribute to the formation and differentiation of subtelomeric regions in Triticeae species.

  4. Giemsa C-banding in two polyploid, South American Hordeum species, H. tetraploidum and H. lechleri, and their aneuploid hybrids with H. vulgare

    DEFF Research Database (Denmark)

    Linde-Laursen, Ib; Bothmer, R. von

    1986-01-01

    American taxa of the same sections suggest a rather close relationship and support that the biological basis for their classification with different sections is questionable. C-banding patterns identified the chromosomes of parental genomes in interspecific hybrids between the two species and H. vulgare....... The hybrids were stably aneuploid. Both had lost and acquired H. vulgare chromosomes. Thus, somatic elimination of chromosomes was combined with multiplication of chromosomes. The observations of stably aneuploid hybrids have implications for the exploitation of alien germplasm. The activity of non-H. vulgare...

  5. Analysis of Essential Oil in Jerusalem Artichoke (Helianthus tuberosus L.) Leaves and Tubers by Gas Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Helmi, Zead; Al Azzam, Khaldun Mohammad; Tsymbalista, Yuliya; Ghazleh, Refat Abo; Shaibah, Hassan; Aboul-Enein, Hassan

    2014-12-01

    To investigate, for the first time, the chemical composition of essential oil of the tubers and leaves of Jerusalem artichoke (Helianthus tuberosus L.), a species of sunflower native to eastern North America, growing in Ukraine. A hydrodistillation apparatus was used for the extraction of volatile components and then it was analysed by gas chromatography equipped with a split-splitless injector (split ratio, 1:50) and flame ionization detector (FID). The oil was analyzed under linear temperature programming applied at 4°C/min from 50°C - 340°C. Temperatures of the injector and FID detector were maintained at 280°C and 300°C, respectively. The chemical analysis of the oil was carried out using gas chromatography coupled to mass spectrometry (GC-MS), to determine the chemical composition of the volatile fraction. The essential oils content ranged from 0.00019 to 0.03486 and 0.00011 to 0.00205 (g/100g), in leaves and tubers, respectively. The qualitative and quantitative analysis led to the identification of 17 components in both species samples. The major component found in leaves and tubers was (-)-β-bisabolene with 70.7% and 63.1%, respectively. Essential oil profile of Jerusalem artichoke species showed significant differences between leaves and tubers species. Additionally, the leaves of Jerusalem artichoke are a promising source of natural β-bisabolene.

  6. Are both sympatric species Ilex perado and Ilex canariensis secretly hybridizing? Indication from nuclear markers collected in Tenerife

    Directory of Open Access Journals (Sweden)

    Manen Jean-François

    2004-11-01

    Full Text Available Abstract Background Intra-specific and intra-individual polymorphism is frequently observed in nuclear markers of Ilex (Aquifoliaceae and discrepancy between plastid and nuclear phylogenies is the rule in this genus. These observations suggest that inter-specific plastid or/and nuclear introgression played an important role in the process of evolution of Ilex. With the aim of a precise understanding of the evolution of this genus, two distantly related sympatric species collected in Tenerife (Canary Islands, I. perado and I. canariensis, were studied in detail. Introgression between these two species was previously never reported. One plastid marker (the atpB-rbcL spacer and two nuclear markers, the ribosomal internal transcribed spacer (ITS and the nuclear encoded plastid glutamine synthetase (nepGS were analyzed for 13 and 27 individuals of I. perado and I. canariensis, respectively. Results The plastid marker is intra-specifically constant and correlated with species identity. On the other hand, whereas the nuclear markers are conserved in I. perado, they are highly polymorphic in I. canariensis. The presence of pseudogenes and recombination in ITS sequences of I. canariensis explain this polymorphism. Ancestral sequence polymorphism with incomplete lineage sorting, or past or recent hybridization with an unknown species could explain this polymorphism, not resolved by concerted evolution. However, as already reported for many other plants, past or recent introgression of an alien genotype seem the most probable explanation for such a tremendous polymorphism. Conclusions Data do not allow the determination with certitude of the putative species introgressing I. canariensis, but I. perado is suspected. The introgression would be unilateral, with I. perado as the male donor, and the paternal sequences would be rapidly converted in highly divergent and consequently unidentifiable pseudogenes. At least, this study allows the establishment of

  7. An Interval Type-2 Fuzzy System with a Species-Based Hybrid Algorithm for Nonlinear System Control Design

    Directory of Open Access Journals (Sweden)

    Chung-Ta Li

    2014-01-01

    Full Text Available We propose a species-based hybrid of the electromagnetism-like mechanism (EM and back-propagation algorithms (SEMBP for an interval type-2 fuzzy neural system with asymmetric membership functions (AIT2FNS design. The interval type-2 asymmetric fuzzy membership functions (IT2 AFMFs and the TSK-type consequent part are adopted to implement the network structure in AIT2FNS. In addition, the type reduction procedure is integrated into an adaptive network structure to reduce computational complexity. Hence, the AIT2FNS can enhance the approximation accuracy effectively by using less fuzzy rules. The AIT2FNS is trained by the SEMBP algorithm, which contains the steps of uniform initialization, species determination, local search, total force calculation, movement, and evaluation. It combines the advantages of EM and back-propagation (BP algorithms to attain a faster convergence and a lower computational complexity. The proposed SEMBP algorithm adopts the uniform method (which evenly scatters solution agents over the feasible solution region and the species technique to improve the algorithm’s ability to find the global optimum. Finally, two illustrative examples of nonlinear systems control are presented to demonstrate the performance and the effectiveness of the proposed AIT2FNS with the SEMBP algorithm.

  8. Volatile Compounds in the Flowers of Freesia Parental Species and Hybrids

    Institute of Scientific and Technical Information of China (English)

    Yang Fu; Xiang Gao; Yiqun Xue; Yuejun Hui; Fengqing Chen; Quanping Su; Li Wang

    2007-01-01

    For centuries, freesia has been one of the most Important crops in the floriculture industry.Here, aqua-space samples collected from entire flowers of diploid Freesia refracta, three tetraploid freesia cuItivare, and interspecific hybrids of three tetraploid freesia cultivars were analyzed using gas chromatograph coupled with mass selective detector.In all, 75 different compounds were identified.The compounds were mainly terpenes, hydrocarbons, alcohols, fatty acid esters and aromatic class compounds.Among these, Iinalool was detected from all the sweet-scented flowers except for scentless white tetraploid F.hybrida.Stable inheritance of linalool between F.hybrida and their F1 progeny was observed.Based on the present analyses, the relationship between the aroma of freesia and linalool was discussed.

  9. A complex genetic basis to X-linked hybrid male sterility between two species of house mice.

    Science.gov (United States)

    Good, Jeffrey M; Dean, Matthew D; Nachman, Michael W

    2008-08-01

    The X chromosome plays a central role in the evolution of reproductive isolation, but few studies have examined the genetic basis of X-linked incompatibilities during the early stages of speciation. We report the results of a large experiment focused on the reciprocal introgression of the X chromosome between two species of house mice, Mus musculus and M. domesticus. Introgression of the M. musculus X chromosome into a wild-derived M. domesticus genetic background produced male-limited sterility, qualitatively consistent with previous experiments using classic inbred strains to represent M. domesticus. The genetic basis of sterility involved a minimum of four X-linked factors. The phenotypic effects of major sterility QTL were largely additive and resulted in complete sterility when combined. No sterility factors were uncovered on the M. domesticus X chromosome. Overall, these results revealed a complex and asymmetric genetic basis to X-linked hybrid male sterility during the early stages of speciation in mice. Combined with data from previous studies, we identify one relatively narrow interval on the M. musculus X chromosome involved in hybrid male sterility. Only a handful of spermatogenic genes are within this region, including one of the most rapidly evolving genes on the mouse X chromosome.

  10. Species origin of genomic factors in Nicotiana nudicaulis Watson controlling hybrid lethality in interspecific hybrids between N. nudicaulis Watson and N. tabacum L.

    Directory of Open Access Journals (Sweden)

    Hongshuo Liu

    Full Text Available Hybrid lethality is expressed at 28°C in the cross Nicotiana nudicaulis × N. tabacum. The S subgenome of N. tabacum has been identified as controlling this hybrid lethality. To clarify the responsible genomic factor(s of N. nudicaulis, we crossed N. trigonophylla (paternal progenitor of N. nudicaulis with N. tabacum, because hybrids between N. sylvestris (maternal progenitor of N. nudicaulis and N. tabacum are viable when grown in a greenhouse. In the cross N. trigonophylla×N. tabacum, approximately 50% of hybrids were vitrified, 20% were viable, and 20% were nonviable at 28°C. To reveal which subgenome of N. tabacum was responsible for these phenotypes, we crossed N. trigonophylla with two progenitors of N. tabacum, N. sylvestris (SS and N. tomentosiformis (TT. In the cross N. sylvestris × N. trigonophylla, we confirmed that over half of hybrids of N. sylvestris × N. trigonophylla were vitrified, and none of the hybrids of N. trigonophylla × N. tomentosiformis were. The results imply that the S subgenome, encoding a gene or genes inducing hybrid lethality in the cross between N. nudicaulis and N. tabacum, has one or more genomic factors that induce vitrification. Furthermore, in vitrified hybrids of N. trigonophylla × N. tabacum and N. sylvestris × N. trigonophylla, we found that nuclear fragmentation, which progresses during expression of hybrid lethality, was accompanied by vitrification. This observation suggests that vitrification has a relationship to hybrid lethality. Based on these results, we speculate that when N. nudicaulis was formed approximately 5 million years ago, several causative genomic factors determining phenotypes of hybrid seedlings were inherited from N. trigonophylla. Subsequently, genome downsizing and various recombination-based processes took place. Some of the causative genomic factors were lost and some became genomic factor(s controlling hybrid lethality in extant N. nudicaulis.

  11. Species origin of genomic factors in Nicotiana nudicaulis Watson controlling hybrid lethality in interspecific hybrids between N. nudicaulis Watson and N. tabacum L.

    Science.gov (United States)

    Liu, Hongshuo; Marubashi, Wataru

    2014-01-01

    Hybrid lethality is expressed at 28°C in the cross Nicotiana nudicaulis × N. tabacum. The S subgenome of N. tabacum has been identified as controlling this hybrid lethality. To clarify the responsible genomic factor(s) of N. nudicaulis, we crossed N. trigonophylla (paternal progenitor of N. nudicaulis) with N. tabacum, because hybrids between N. sylvestris (maternal progenitor of N. nudicaulis) and N. tabacum are viable when grown in a greenhouse. In the cross N. trigonophylla×N. tabacum, approximately 50% of hybrids were vitrified, 20% were viable, and 20% were nonviable at 28°C. To reveal which subgenome of N. tabacum was responsible for these phenotypes, we crossed N. trigonophylla with two progenitors of N. tabacum, N. sylvestris (SS) and N. tomentosiformis (TT). In the cross N. sylvestris × N. trigonophylla, we confirmed that over half of hybrids of N. sylvestris × N. trigonophylla were vitrified, and none of the hybrids of N. trigonophylla × N. tomentosiformis were. The results imply that the S subgenome, encoding a gene or genes inducing hybrid lethality in the cross between N. nudicaulis and N. tabacum, has one or more genomic factors that induce vitrification. Furthermore, in vitrified hybrids of N. trigonophylla × N. tabacum and N. sylvestris × N. trigonophylla, we found that nuclear fragmentation, which progresses during expression of hybrid lethality, was accompanied by vitrification. This observation suggests that vitrification has a relationship to hybrid lethality. Based on these results, we speculate that when N. nudicaulis was formed approximately 5 million years ago, several causative genomic factors determining phenotypes of hybrid seedlings were inherited from N. trigonophylla. Subsequently, genome downsizing and various recombination-based processes took place. Some of the causative genomic factors were lost and some became genomic factor(s) controlling hybrid lethality in extant N. nudicaulis.

  12. Genetic Basis for Spontaneous Hybrid Genome Doubling during Allopolyploid Speciation of Common Wheat Shown by Natural Variation Analyses of the Paternal Species

    Science.gov (United States)

    Matsuoka, Yoshihiro; Nasuda, Shuhei; Ashida, Yasuyo; Nitta, Miyuki; Tsujimoto, Hisashi; Takumi, Shigeo; Kawahara, Taihachi

    2013-01-01

    The complex process of allopolyploid speciation includes various mechanisms ranging from species crosses and hybrid genome doubling to genome alterations and the establishment of new allopolyploids as persisting natural entities. Currently, little is known about the genetic mechanisms that underlie hybrid genome doubling, despite the fact that natural allopolyploid formation is highly dependent on this phenomenon. We examined the genetic basis for the spontaneous genome doubling of triploid F1 hybrids between the direct ancestors of allohexaploid common wheat (Triticum aestivum L., AABBDD genome), namely Triticumturgidum L. (AABB genome) and Aegilopstauschii Coss. (DD genome). An Ae. tauschii intraspecific lineage that is closely related to the D genome of common wheat was identified by population-based analysis. Two representative accessions, one that produces a high-genome-doubling-frequency hybrid when crossed with a T. turgidum cultivar and the other that produces a low-genome-doubling-frequency hybrid with the same cultivar, were chosen from that lineage for further analyses. A series of investigations including fertility analysis, immunostaining, and quantitative trait locus (QTL) analysis showed that (1) production of functional unreduced gametes through nonreductional meiosis is an early step key to successful hybrid genome doubling, (2) first division restitution is one of the cytological mechanisms that cause meiotic nonreduction during the production of functional male unreduced gametes, and (3) six QTLs in the Ae. tauschii genome, most of which likely regulate nonreductional meiosis and its subsequent gamete production processes, are involved in hybrid genome doubling. Interlineage comparisons of Ae. tauschii’s ability to cause hybrid genome doubling suggested an evolutionary model for the natural variation pattern of the trait in which non-deleterious mutations in six QTLs may have important roles. The findings of this study demonstrated that the

  13. Genetic basis for spontaneous hybrid genome doubling during allopolyploid speciation of common wheat shown by natural variation analyses of the paternal species.

    Directory of Open Access Journals (Sweden)

    Yoshihiro Matsuoka

    Full Text Available The complex process of allopolyploid speciation includes various mechanisms ranging from species crosses and hybrid genome doubling to genome alterations and the establishment of new allopolyploids as persisting natural entities. Currently, little is known about the genetic mechanisms that underlie hybrid genome doubling, despite the fact that natural allopolyploid formation is highly dependent on this phenomenon. We examined the genetic basis for the spontaneous genome doubling of triploid F1 hybrids between the direct ancestors of allohexaploid common wheat (Triticum aestivum L., AABBDD genome, namely Triticumturgidum L. (AABB genome and Aegilopstauschii Coss. (DD genome. An Ae. tauschii intraspecific lineage that is closely related to the D genome of common wheat was identified by population-based analysis. Two representative accessions, one that produces a high-genome-doubling-frequency hybrid when crossed with a T. turgidum cultivar and the other that produces a low-genome-doubling-frequency hybrid with the same cultivar, were chosen from that lineage for further analyses. A series of investigations including fertility analysis, immunostaining, and quantitative trait locus (QTL analysis showed that (1 production of functional unreduced gametes through nonreductional meiosis is an early step key to successful hybrid genome doubling, (2 first division restitution is one of the cytological mechanisms that cause meiotic nonreduction during the production of functional male unreduced gametes, and (3 six QTLs in the Ae. tauschii genome, most of which likely regulate nonreductional meiosis and its subsequent gamete production processes, are involved in hybrid genome doubling. Interlineage comparisons of Ae. tauschii's ability to cause hybrid genome doubling suggested an evolutionary model for the natural variation pattern of the trait in which non-deleterious mutations in six QTLs may have important roles. The findings of this study demonstrated

  14. Interspecific Hybridization AmongVigna Species%豇豆属食用豆类间的远缘杂交

    Institute of Scientific and Technical Information of China (English)

    刘长友; 范保杰; 曹志敏; 苏秋竹; 王彦; 张志肖; 程须珍; 田静

    2015-01-01

    粒的发育;黑吉豆与小豆、饭豆杂交时存在胚败育现象;饭豆作母本与小豆杂交经幼胚拯救可以获得可育的F1植株;小豆与近缘野生种的杂交亲和性优于饭豆;豇豆与其他食用豆类间杂交均未成功。%Objective]The aim of this study was to analyze the crossability of differentVigna species, which will facilitate the distant hybridization breeding ofVigna.[Method] Interspecific crossabilities were investigated among 5 cultivar species of Vigna,V. radiata (mungbean),V. mungo (black gram),V. umbellata (rice bean),V. anguluris (adzuki bean),V. unguiculata (cowpea), and 3 wild relative species of adzuki bean,V. minima,V. nakashiame andV. riukiuensis. Embryo rescue was conducted for 3 interspecific combinations, namely,V. radiata×V. angularis,V. angularis×V. umbellataandV. umbellata×V. angularis, respectively. The pod setting ratio of hybrid and performance of F1 plant were investigated to analyze the crossabilities between food legumes ofVigna genus.[Result] The genetic relationship between different food legumes and the choice of female parent influenced the result of distant hybridization. Except for cowpea cross combinations, hybrid pods were set successfully in the other interspecific crosses. The growth of hybrid pods and seeds showed variations in different combinations. No genetic disorders before fertilization were found from the hybridizations ofV. radiata×V. mungo,V. angularis×V. minima,V. angularis×V. nakashiame, andV. angularis×V. riukiuensis. The hybrid seeds of them germinated normally, and the hybrid plants were fertile, but the fruiting rates were lower. The pod setting ratio was significantly higher whenV. radiatawas selected as female parent in the interspecific crosses betweenV. radiataandV. umbellata. F1 plants were obtained without embryo culture, but they showed complete hybrid sterility. No fertile seeds were obtained even backcross toV. radiataorV. umbellata. Hybrid plants were obtained from cultured

  15. Visual definition of physiological maturity in sunflower (Helianthus annuus L. is associated with receptacle quantitative color parameters

    Directory of Open Access Journals (Sweden)

    L. F. Hernandez

    2013-04-01

    Full Text Available Identifying physiological maturity (PM in sunflower (Helianthus annuus L. by visual methods is subjective. The present study was conducted during two years in two short season sunflower hybrids (Macón and MG60 to determine the relationship between quantitative color parameters in the receptacle and physiological markers such as fruit dry weight (FDW and fruit water content (FWC from flowering to PM. Fruits from the external 25% of the capitulum radius were sampled at 3-5-day intervals from first anthesis until harvest maturity. Fruit and receptacle fresh and dry weight were calculated, and color changes of the receptacle base were followed over time using a spectrophotometer. Comparison of colorimetric coordinates a* and b*, defined by the CIELAB color space enabled quantitative correlation of color changes in the receptacle with the maturation stage of the fruits and their moisture content. In both hybrids and years, fruits attained maximum dry weight when the receptacle color turned from dark green to buttery-yellow. Strong correlations were found between FWC and a* for Macón the first (r=-0.877 and second year (r=-0.934 and for MG60, (r=-0.912 and r=-0.891 the first and second year, respectively. The same results were found for b* for Macón (r=-0.901 and r=-0.829 and for MG60 (r=-0.898 and r= -0.863 for the first and second year respectively. Maximum b* at FWC between 40 to 41% had the highest correlation with maximum fruit dry weight for both hybrids and years, and was a good indicator for identifying the attainment of PM. This work represents an original contribution and a first step towards the development of a model for predicting PM in sunflower by using colorimetric measurements.

  16. Toward a molecular cytogenetic map for cultivated sunflower (Helianthus annuus L.) by landed BAC/BIBAC clones.

    Science.gov (United States)

    Feng, Jiuhuan; Liu, Zhao; Cai, Xiwen; Jan, Chao-Chien

    2013-01-01

    Conventional karyotypes and various genetic linkage maps have been established in sunflower (Helianthus annuus L., 2n = 34). However, the relationship between linkage groups and individual chromosomes of sunflower remains unknown and has considerable relevance for the sunflower research community. Recently, a set of linkage group-specific bacterial /binary bacterial artificial chromosome (BAC/BIBAC) clones was identified from two complementary BAC and BIBAC libraries constructed for cultivated sunflower cv. HA89. In the present study, we used these linkage group-specific clones (~100 kb in size) as probes to in situ hybridize to HA89 mitotic chromosomes at metaphase using the BAC-fluorescence in situ hybridization (FISH) technique. Because a characteristic of the sunflower genome is the abundance of repetitive DNA sequences, a high ratio of blocking DNA to probe DNA was applied to hybridization reactions to minimize the background noise. As a result, all sunflower chromosomes were anchored by one or two BAC/BIBAC clones with specific FISH signals. FISH analysis based on tandem repetitive sequences, such as rRNA genes, has been previously reported; however, the BAC-FISH technique developed here using restriction fragment length polymorphism (RFLP)-derived BAC/BIBAC clones as probes to apply genome-wide analysis is new for sunflower. As chromosome-specific cytogenetic markers, the selected BAC/BIBAC clones that encompass the 17 linkage groups provide a valuable tool for identifying sunflower cytogenetic stocks (such as trisomics) and tracking alien chromosomes in interspecific crosses. This work also demonstrates the potential of using a large-insert DNA library for the development of molecular cytogenetic resources.

  17. On the origin of asexual species by means of hybridization and drift

    DEFF Research Database (Denmark)

    Hartfield, Matthew

    2016-01-01

    Several species of asexuals appear to have existed for millions of years. This is despite the prevalent view that natural selection is weakened without gene exchange, which should cause these organisms to rapidly go extinct. In theory, one can identify evolutionary long-lived asexuals from...

  18. Optimizing culture medium for meristem tissue culture of several Saccharum species and commercial hybrids

    Science.gov (United States)

    The optimal range of medium nutrients and plant growth regulators (PGR) was investigated for in vitro culture of diverse sugarcane species and cultivars. Macro-nutrients, nitrogen (N), phosphorous (P) and potassium (K), were essential for growth of leaf primordia. Although the best concentration of ...

  19. Development of genetic markers distinguishing two invasive fire ant species (Hymenoptera: Formicidae) and their hybrids

    Science.gov (United States)

    Three SNP markers were developed that are completely diagnostic in distinguishing the two fire ant species Solenopsis invicta and S. richteri. Although a fourth marker we developed is not fully diagnostic, it is still useful given one of the variants is confined to S. richteri. Joint use of these ma...

  20. Ethylene-mediated regulation of gibberellin content and growth in helianthus annuus L

    Energy Technology Data Exchange (ETDEWEB)

    Pearce, D.W.; Reid, D.M.; Pharis, R.P. (Univ. of Calgary, Alberta (Canada))

    1991-04-01

    Elongation of hypocotyls of sunflower can be promoted by gibberellins (GAs) and inhibited by ethylene. The role of these hormones in regulating elongation was investigated by measuring changes in both endogenous GAs and in the metabolism of exogenous ({sup 3}H)- and ({sup 2}H{sub 2})GA{sub 20} in the hypocotyls of sunflower (Helianthus annuus L. cv Delgren 131) seedlings exposed to ethylene. The major biologically active GAs identified by gas chromatography-mass spectrometry were GA{sub 1}, GA{sub 19}, GA{sub 20}, and GA{sub 44}. In hypocotyls of seedlings exposed to ethylene, the concentration of GA{sub 1}, known to be directly active in regulating shoot elongation in a number of species, was reduced. Ethylene treatment reduced the metabolism of ({sup 3}H)GA{sub 20} and less ({sup 2}H{sub 2})GA{sub 1} was found in the hypocotyls of those seedlings exposed to the higher ethylene concentrations. However, it is not known if the effect of ethylene on GA{sub 20} metabolism was direct or indirect. In seedlings treated with exogenous GA{sub 1} or GA{sub 3}, the hypocotyls elongated faster than those of controls, but the GA treatment only partially overcame the inhibitory effect of ethylene on elongation. The authors conclude that GA content is a factor which may limit elongation in hypocotyls of sunflower, and that while exposure to ethylene results in reduced concentration of GA{sub 1} this is not sufficient per se to account for the inhibition of elongation caused by ethylene.

  1. Pseudoxanthomonas helianthi sp. nov., isolated from roots of Jerusalem artichoke (Helianthus tuberosus).

    Science.gov (United States)

    Kittiwongwattana, Chokchai; Thawai, Chitti

    2016-12-01

    A bacterium designated as strain roo10T was isolated from roots of Jerusalem artichoke (Helianthus tuberosus). Cells were Gram-stain-negative and non-motile rods. The phylogenetic analysis of the 16S rRNA gene indicated that it represented a member of the genus Pseudoxanthomonas, and its close relatives included Pseudoxanthomonas kalamensis JA40T (97.8 % 16S rRNA gene sequence similarity), Pseudoxanthomonas sangjuensis 5GH38-5T (97.7 %) and Pseudoxanthomonas daejeonensis TR6-08T (97.1 %). Growth of roo10T occurred at pH 7-9. The temperature for growth ranged from 20 to 37 °C. Tolerance to NaCl was observed from 0.005 to 5 % (w/v) concentration. Predominant fatty acids were iso-C15 : 0 (23.5 %), iso-C16 : 0 (18.9 %) and anteiso-C15 : 0 (11.5 %). Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidyl-N-methylethanolamine were the major polar lipids. The predominant quinone was ubiquinone 8 (Q-8). The DNA G+C content was 65.7 mol% [from melting temperature (Tm)]. Comparison of phenotypic and chemotaxonomic characteristics indicated that roo10T was distinguishable from its close relatives. Additionally, the DNA-DNA relatedness levels between roo10T and P. kalamensis DSM 18571T (22±0.5 %), P. sangjuensis 5GH38-5T (21±0.2 %) and P. daejeonensis DSM 17801T (3±1 %) were lower than 70 %. These results indicated that roo10T represented a novel species of the genus Pseudoxanthomonas, for which the name Pseudoxanthomonas helianthi sp. nov. is proposed. The type strain is roo10T (=BCC 70700T=NBRC 110414T).

  2. Oxygen toxicity and antioxidative responses in arsenic stressed Helianthus annuus L. seedlings against UV-B.

    Science.gov (United States)

    Yadav, Geeta; Srivastava, Prabhat Kumar; Parihar, Parul; Tiwari, Sanjesh; Prasad, Sheo Mohan

    2016-12-01

    In order to know the impact of elevated level of UV-B on arsenic stressed Helianthus annuus L. var. DRSF-113 plants, certain physiological (growth - root and shoot lengths, their fresh masses and leaf area; photosynthetic competence and respiration) and biochemical parameters (pigments - Chl a and b, Car, anthocyanin and flavonoids; reactive oxygen species - superoxide radicals, H2O2; reactive carbonyl group, electrolyte leakage; antioxidants - superoxide dismutase, peroxidise, catalase, glutathione-S-transferase, proline) of their seedlings were analysed under the simultaneous exposures of two arsenic doses (6mgkg(-1) soil, As1; and 12mgkg(-1) soil, As2) and two UV-B doses (1.2kJm(-2)d(-1), UV-B1; and 3.6kJm(-2)d(-1), UV-B2). As1 and As2 alone declined all the studied growth parameters - along with photosynthetic pigments which were further aggravated after the simultaneous exposures of predefined levels of UV-B. Each As exposure was accompanied by significant accumulation of As in root, shoot and leaves and was substantiated by simultaneous exposures of UV-B doses which manifested into suppressed growth, decreased chlorophyll contents and photosynthesis. In similar conditions, other photo-shielding pigments, viz. carotenoids, anthocyanin and flavonoids along with respiration and oxidative stress markers such as O2(•)¯, H2O2; and indicators of cell membrane damage like MDA (malondialdehyde), RCG (reactive carbonyl group), electrolyte leakage were enhanced by As, and became more pronounced after the simultaneous exposures of UV-B doses. As doses stimulated the activities of SOD, POD, CAT, GST and Pro which got further accelerated after the simultaneous exposures of UV-B doses.

  3. Growth responses of plants to various concentrations of nitrogen dioxide. [Helianthus annuus L. ; Zea mays L

    Energy Technology Data Exchange (ETDEWEB)

    Okano, K.; Totsuka, T.; Fukuzawa, T.; Tazaki, T.

    1985-01-01

    Sunflower Helianthus annuus L. and maize Zea mays L. plants in the vegetative phase were exposed to nitrogen dioxide (NO2) at 0.0 (control), 0.2, 0.5 and 1.0 ppm ( l liter ) for 2 weeks. The growth responses of the plants to NO2 were examined by the techniques of growth analysis. The sunflower plant was more susceptible to NO2 than the maize plant. Exposure to NO2 at 0.2 ppm slightly stimulated the growth of the sunflower plants. The net assimilation rate (NAR) was also significantly increased when the plants were exposed to 0.2 ppm NO2. Exposures to NO2 at 0.5 or more significantly reduced the dry weight of the sunflower plant. Of the component parts, the roots and stems were severely affected, while the leaves were less affected. This resulted in an elevated shoot/root ratio. The net assimilation rate of both species was reduced by the exposures to NO2 at 0.5 ppm or more, while, in contrast, the leaf area ratio (LAR) was increased. The relative growth rate (RGR), the product of the NAR and the LAR, was therefore less affected by NO2. The increase in the LAR was overwhelmingly the result of an increase in the leaf weight ratio (LWR). These results imply that a reduction in photosynthetic efficiency induced by NO2 could be, in part, compensated for by an increase in assimilatory area, suggesting an adaptive growth response of the plants to air pollutant stresses.

  4. Nitrogen and sugar content variability in tubers of Jerusalem artichoke (Helianthus tuberosus

    Directory of Open Access Journals (Sweden)

    Terzić Sreten

    2009-01-01

    Full Text Available Several nutritive values for tubers of 114 Jerusalem artichoke (Helianthus tuberosus populations were evaluated during 2006. The used material is a part of wild sunflower species collection at the Institute of field and vegetable crops and it is situated in Rimski Šancevi, Novi Sad. The samples were analyzed as fresh tubers on 'Venema' automatic laboratory for alpha amino nitrogen, sodium and potassium content. Total sugar content was determined as the brix value on a refractometer. Total nitrogen was determined by the Kjeldahl method on dried samples. Significant variability was found for all analyzed traits. Total nitrogen varied from 0,695 to 2,179% dry weight (mean 1,23%, alpha amino nitrogen content 0,012 to 0,118% fresh weight (m. 0,07%, potassium 0,231 0,452% fresh weight (m. 0,403% and sodium 0,0003 - 0,0143% fresh weight (m. 0,007%. Total sugar content varied from 13,69 - 22,94% fresh weight (m. 19,14%. Alpha amino nitrogen is an essential nutrient for animals so that it's presence in tubers of Jerusalem artichoke as food is positive. The protein content is similar to the one in potato and as such satisfactory for nutrition. The K/Na ratio is high which is useful, because an increased content of potassium in food can positively affect the reduction of Na/K ratio and lower systolic blood pressure by a significant amount in adults with mild hypertension. Inulin makes up to 80% of the total sugar content in the tubers of Jerusalem artichoke, and as a dietary fiber and a fructose polymer it positively influences digestion and sugar blood levels. The obtained results suggest that selection of cultivars and populations with inappropriate nutritive values is possible. Further research is needed to estimate the share of genetic in total variability and to determine whether the selection for new cultivars is justified.

  5. Glycoalkaloid aglycone accumulations associated with infection by Clavibacter michiganensis ssp. sepedonicus in potato species Solanum acaule and Solanum tuberosum and their interspecific somatic hybrids.

    Science.gov (United States)

    Rokka, V-M; Laurila, J; Tauriainen, A; Laakso, I; Larkka, J; Metzler, M; Pietilä, L

    2005-03-01

    Solanum acaule Bitt., a wild potato species, is closely related to cultivated potato (Solanum. tuberosum L.). Incorporation of desirable traits from allotetraploid [2n=4x=48, 2 endosperm balance number (EBN)] S. acaule (acl) into autotetraploid (2n=4x=48, 4EBN) S. tuberosum (tbr) is difficult due to incongruity boundaries. In this study, three hybrid combinations, each with a specific genome constitution, were produced through protoplast fusion: (1) hexaploid 2x acl (+) 4x tbr, (2) tetraploid 2x acl (+) 2x tbr, and (3) hexaploid 4x acl (+) 2x tbr hybrids. In terms of glycoalkaloid aglycones, the hybrids produced demissidine, tomatidine and solanidine, similarly to the S. acaule parental species, but S. tuberosum synthesised only solanidine. Inoculations with Clavibacter michiganensis ssp. sepedonicus (Cms), which is the causal agent of bacterial ring rot in potato, yielded significantly lower total glycoalkaloid aglycone accumulation both in S. acaule plants and in interspecific hybrids in comparison with the corresponding mock-inoculated plants. However, in S. tuberosum the aglycone levels were either higher or unchanged as a result of infection by Cms. To incorporate the desirable traits of the interspecific somatic hybrids into 4EBN S. tuberosum, sexual backcrosses were carried out. The hexaploid 4x acl (+) 2x tbr hybrids with the hypothetical 4EBN showed the greatest capacity to undergo backcrosses with S. tuberosum.

  6. The genetics of hybrid male sterility between the allopatric species pair Drosophila persimilis and D. pseudoobscura bogotana: dominant sterility alleles in collinear autosomal regions.

    Science.gov (United States)

    Chang, Audrey S; Noor, Mohamed A F

    2007-05-01

    F(1) hybrid male sterility is thought to result from interactions between loci on the X chromosome and dominant-acting loci on the autosomes. While X-linked loci that contribute to hybrid male sterility have been precisely localized in many animal taxa, their dominant autosomal interactors have been more difficult to localize precisely and/or have been shown to be of relatively smaller effect. Here, we identified and mapped at least four dominant autosomal factors contributing to hybrid male sterility in the allopatric species pair Drosophila persimilis and D. pseudoobscura bogotana. Using these results, we tested predictions of reduced recombination models of speciation. Consistent with these models, three of the four QTL associated with hybrid male sterility occur in collinear (uninverted) regions of these genomes. Furthermore, these QTL do not contribute significantly to hybrid male sterility in crosses between the sympatric species D. persimilis and D. pseudoobscura pseudoobscura. The autosomal loci identified in this study provide the basis for introgression mapping and, ultimately, for molecular cloning of interacting genes that contribute to F(1) hybrid sterility.

  7. Influence of light on DNA content of Helianthus annuus Linnaeus.

    Science.gov (United States)

    Price, H J; Johnston, J S

    1996-10-01

    Mean nuclear 2C DNA content (C equaling haploid DNA per nucleus) of the first leaf of the sunflower, Helianthus annuus L., is influenced by the quality and the quantity of light. Seedlings of two inbred lines, RHA 299 and RHA 271 were germinated and grown in controlled environmental conditions. Lighting was adjusted to provide different combinations of photon flux densities and red to far red (R:FR) ratios. At R:FR = 5.8 and photon flux densities of 170 mumol.m-2.s-1, 200 mumol.m-2.s-1, and 230 mumol.m-2.s-1, DNA content remained high and relatively constant (x = 6.97 pg for RHA 271 and x = 7.32 pg for RHA 299). When the photon flux density range (R:FR = 5.8) was elevated to 350 mumol.m-2.s-1, 410 mumol.m-2.s-1, and 470 mumol.m-2.s-1, mean DNA content was reduced to 6.23 pg (RHA 271) and 6.46 pg (RHA 299). At R:FR = 1.5, mean DNA content was consistently high (7.2-7.9 pg) only at the lowest photon flux density of 170 mumol.m-2.s-1. Significant decreases in DNA content (densities of 200 mumol.m-2.s-1 and 230 mumol.m-2.s-1. At the higher photon flux densities (350 mumol.m-2.s-1, 410 mumol.m-2.s-1, and 470 mumol.m-2.s-1) and R:RF = 1.5, the plants had extremely low DNA contents (mean x = 3.36 pg for RHA 271 and 3.41 pg for RHA 299) and high between-plant variance. The instability of DNA content, particularly for plants grown under light that is far red rich, suggests that phytochromes may be involved in regulating DNA content of the sunflower.

  8. Development and characterization of novel EST-SSR markers and their application for genetic diversity analysis of Jerusalem artichoke (Helianthus tuberosus L.).

    Science.gov (United States)

    Mornkham, T; Wangsomnuk, P P; Mo, X C; Francisco, F O; Gao, L Z; Kurzweil, H

    2016-10-24

    Jerusalem artichoke (Helianthus tuberosus L.) is a perennial tuberous plant and a traditional inulin-rich crop in Thailand. It has become the most important source of inulin and has great potential for use in chemical and food industries. In this study, expressed sequence tag (EST)-based simple sequence repeat (SSR) markers were developed from 40,362 Jerusalem artichoke ESTs retrieved from the NCBI database. Among 23,691 non-redundant identified ESTs, 1949 SSR motifs harboring 2 to 6 nucleotides with varied repeat motifs were discovered from 1676 assembled sequences. Seventy-nine primer pairs were generated from EST sequences harboring SSR motifs. Our results show that 43 primers are polymorphic for the six studied populations, while the remaining 36 were either monomorphic or failed to amplify. These 43 SSR loci exhibited a high level of genetic diversity among populations, with allele numbers varying from 2 to 7, with an average of 3.95 alleles per loci. Heterozygosity ranged from 0.096 to 0.774, with an average of 0.536; polymorphic index content ranged from 0.096 to 0.854, with an average of 0.568. Principal component analysis and neighbor-joining analysis revealed that the six populations could be divided into six clusters. Our results indicate that these newly characterized EST-SSR markers may be useful in the exploration of genetic diversity and range expansion of the Jerusalem artichoke, and in cross-species application for the genus Helianthus.

  9. Bradyrhizobia Nodulating the Acacia mangium × A. auriculiformis Interspecific Hybrid Are Specific and Differ from Those Associated with Both Parental Species ▿ †

    Science.gov (United States)

    Le Roux, Christine; Tentchev, Diana; Prin, Yves; Goh, Doreen; Japarudin, Yani; Perrineau, Marie-Mathilde; Duponnois, Robin; Domergue, Odile; de Lajudie, Philippe; Galiana, Antoine

    2009-01-01

    In the context of an increasing utilization of the interspecific hybrid Acacia mangium × A. auriculiformis as a plantation tree in the tropical humid zone, its symbiotic characterization was carried out in comparison with that of its two parental species. Rhizobium strains of diverse geographical origins were isolated from root nodules of the hybrid and its parents. Almost all Acacia hybrid isolates were fast growing on yeast extract-mannitol medium, in contrast to those isolated from both parental species, which were mostly slow growing. The rhizobium strains were characterized through partial sequencing of the rRNA operon. In the phylogenetic tree, almost all strains isolated from the hybrid were grouped together in a clade close to Bradyrhizobium japonicum, while all strains isolated from both parental species were close to Bradyrhizobium elkanii. Inoculation experiments performed under in vitro or greenhouse conditions showed that all strains were infective with their original hosts but exhibited very variable degrees of effectivity according to the host plant tested. Thus, homologous strain-host associations were more effective than heterologous ones. This shows that there is still a high potential for isolating and testing new strains from hybrids to be used as inoculants in the context of large-scale afforestation programs. PMID:19854923

  10. Bradyrhizobia nodulating the Acacia mangium x A. auriculiformis interspecific hybrid are specific and differ from those associated with both parental species.

    Science.gov (United States)

    Le Roux, Christine; Tentchev, Diana; Prin, Yves; Goh, Doreen; Japarudin, Yani; Perrineau, Marie-Mathilde; Duponnois, Robin; Domergue, Odile; de Lajudie, Philippe; Galiana, Antoine

    2009-12-01

    In the context of an increasing utilization of the interspecific hybrid Acacia mangium x A. auriculiformis as a plantation tree in the tropical humid zone, its symbiotic characterization was carried out in comparison with that of its two parental species. Rhizobium strains of diverse geographical origins were isolated from root nodules of the hybrid and its parents. Almost all Acacia hybrid isolates were fast growing on yeast extract-mannitol medium, in contrast to those isolated from both parental species, which were mostly slow growing. The rhizobium strains were characterized through partial sequencing of the rRNA operon. In the phylogenetic tree, almost all strains isolated from the hybrid were grouped together in a clade close to Bradyrhizobium japonicum, while all strains isolated from both parental species were close to Bradyrhizobium elkanii. Inoculation experiments performed under in vitro or greenhouse conditions showed that all strains were infective with their original hosts but exhibited very variable degrees of effectivity according to the host plant tested. Thus, homologous strain-host associations were more effective than heterologous ones. This shows that there is still a high potential for isolating and testing new strains from hybrids to be used as inoculants in the context of large-scale afforestation programs.

  11. Cross-species hybridization of woodchuck hepatitis virus-induced hepatocellular carcinoma using human oligonucleotide microarrays

    Institute of Scientific and Technical Information of China (English)

    Paul W Anderson; Bud C Tennant; Zhenghong Lee

    2006-01-01

    AIM: To demonstrate the feasibility of using woodchuck samples on human microarrays, to provide insight into pathways involving positron emission tomography (PET) imaging tracers and to identify genes that could be potential molecular imaging targets for woodchuck hepatocellular carcinoma.METHODS: Labeled cRNA from woodchuck tissue samples were hybridized to Affymetrix U133 plus 2.0 GeneChips(R). Ten genes were selected for validation using quantitative RT-PCR and literature review was made.RESULTS: Testis enhanced gene transcript (BAX Inhibitor 1), alpha-fetoprotein, isocitrate dehydrogenase 3 (NAD+) beta, acetyl-CoA synthetase 2, carnitine palmitoyltransferase 2, and N-myc2 were up-regulated and spermidine/spermine N1-acetyltransferase was down-regulated in the woodchuck HCC. We also found previously published results supporting 8 of the 10 most up-regulated genes and all 10 of the 10 most downregulated genes.CONCLUSION: Many of our microarray results were validated using RT-PCR or literature search. Hence, we believe that woodchuck HCC and non-cancerous liver samples can be used on human microarrays to yield meaningful results.

  12. Hybridization of Phenylthiolate- and Methylthiolate-Adatom Species at Low Coverage on the Au(111) Surface

    Science.gov (United States)

    2013-03-07

    thiolate species, methylthiolate and phenylthiolate, on the Au(111) surface. Despite the apparent stability, organometallic complexes of methyl- and...stability, organometallic complexes of methyl- and phenylthiolate with the goldadatom (RS?Au?SR, with R as the hydrocarbon group) undergo a stoichiometric...Electrical and Computer Engineering, University of Toronto, Toronto, ON, M5S 3G4, Canada ∥Department of Chemistry , University of Virginia, Charlottesville

  13. Phytotoxic effects of nickel on yield and concentration of macro- and micro-nutrients in sunflower (Helianthus annuus L.) achenes.

    Science.gov (United States)

    Ahmad, Muhammad Sajid Aqeel; Ashraf, Muhammad; Hussain, Mumtaz

    2011-01-30

    The phytotoxic effects of varying levels of nickel (0, 10, 20, 30, and 40 mg L(-1)) on growth, yield and accumulation of macro- and micro-nutrients in leaves and achenes of sunflower (Helianthus annuus L.) were appraised in this study. A marked reduction in root and shoot fresh biomass was recorded at higher Ni levels. Nickel stress also caused a substantial decrease in all macro- and micro-nutrients in leaves and achenes. The lower level of Ni (10 mg L(-1)) had a non-significant effect on various yield attributes, but higher Ni levels considerably decreased these parameters. Higher Ni levels decreased the concentrations of Ca, Mn and Fe in achenes. In contrast, achene N, K, Zn, Mn and Cu decreased consistently with increasing level of Ni, even at lower level (10 mg L(-1)). Sunflower hybrid Hysun-33 had better yield and higher most of the nutrients in achenes as compared with SF-187. The maximum reduction in all parameters was observed at the maximum level of nickel (40 mg L(-1)) where almost all parameters were reduced more than 50% of those of control plants. In conclusion, the pattern of uptake and accumulation of different nutrients in sunflower plants were nutrient- and cultivar-specific under Ni-stress.

  14. Evidence of Natural Hybridization and Introgression between Vasconcellea Species (Caricaceae) from Southern Ecuador Revealed by Chloroplast, Mitochondrial and Nuclear DNA Markers

    Science.gov (United States)

    VAN DROOGENBROECK, B.; KYNDT, T.; ROMEIJN-PEETERS, E.; VAN THUYNE, W.; GOETGHEBEUR, P.; ROMERO-MOTOCHI, J. P.; GHEYSEN, G.

    2006-01-01

    • Background and Aims Vasconcellea × heilbornii is believed to be of natural hybrid origin between V. cundinamarcensis and V. stipulata, and is often difficult to discriminate from V. stipulata on morphological grounds. The aim of this paper is to examine individuals of these three taxa and of individuals from the closely related species V. parviflora and V. weberbaueri, which all inhabit a hybrid zone in southern Ecuador. • Methods Molecular data from mitochondrial, chloroplast and nuclear DNA from 61 individuals were analysed. • Key Results Molecular analysis confirmed occasional contemporary hybridization between V. stipulata, V. cundinamarcensis and V. × heilbornii and suggested the possible involvement of V. weberbaueri in the origin of V. × heilbornii. In addition, the molecular data indicated unidirectional introgression of the V. cundinamarcensis nuclear genome into that of V. stipulata. Several of the individuals examined with morphology similar to that of V. stipulata had genetic traces of hybridization with V. cundinamarcensis, which only seems to act as pollen donor in interspecific hybridization events. Molecular analyses also strongly suggested that most of the V. × heilbornii individuals are not F1 hybrids but instead are progeny of repeated backcrosses with V. stipulata. • Conclusions The results of the present study point to the need for re-evaluation of natural populations of V. stipulata and V. × heilbornii. In general, this analysis demonstrates the complex patterns of genetic and morphological diversity found in natural plant hybrid zones. PMID:16500954

  15. Molecular mapping of three nuclear male sterility mutant genes in cultivated sunflower (Helianthus annuus L.)

    Science.gov (United States)

    The nuclear male sterility (NMS) trait is a useful tool for sunflower (Helianthus annuus L.) breeding and genetic programs. Previously, we induced NMS mutants in cultivated line HA 89. The mutants possessed single recessive genes, ms6, ms7, and ms8, respectively, in NMS HA 89-872, NMS HA 89-552, and...

  16. Molecular mapping of R11, a novel rust resistance gene in sunflower (Helianthus annuus L.)

    Science.gov (United States)

    Sunflower production in North America has recently been threatened by the evolution of new virulent pathotypes of sunflower rust caused by the fungus Puccinia helianthi Schwein. Rf ANN-1742, an ‘HA 89’ backcross restorer line derived from wild annual sunflower (Helianthus annuus L), was identified a...

  17. Changes in mass and dimensions of sunflower (Helianthus annuus L.) achenes and seeds due to carbonization

    NARCIS (Netherlands)

    Braadbaart, F.; Wright, P.J.

    2007-01-01

    When analyzing sunflower (Helianthus annuus L.) remains, which are often carbonized, archaeobotanists commonly differentiate between wild and domesticated achenes and seeds based on the measured length (L) and width (W) or the calculated index L*W. Carbonization reduces the dimensions. To compensate

  18. Phomopsis stem canker: a re-emerging threat to sunflowers (Helianthus annuus) in the United States

    Science.gov (United States)

    Phomopsis stem canker frequently causes yield reductions on sunflowers (Helianthus annuus L.) on several continents, including Australia, Russia, Europe and North America. Between 2001 and 2012, the incidence of Phomopsis stem canker has increased 16 fold in the Northern Great Plains of the United...

  19. Is The Boron Uptake Affected When Sunflower (Helianthus annuus L.) Grown At Poly Culture Systems?

    OpenAIRE

    YILDIZTEKİN, Mahmut; TUNA, Atilla Levent

    2015-01-01

    n this study, sunflower (Helianthus annuus L.) was growth alone and with wheat (Triticum aestivum L.) and clover plants (Medicago sativa L.). Boron at 25-50-75 mg L-1 concentrations was applied by the foliarly in the forms of Boric

  20. Phytoaccumulation of lead by sunflower (Helianthus annuus), tobacco (Nicotiana tabacum), and vetiver (Vetiveria zizanioides).

    Science.gov (United States)

    Boonyapookana, Benjaporn; Parkpian, Preeda; Techapinyawat, Sombun; DeLaune, R D; Jugsujinda, Aroon

    2005-01-01

    The ability of three plant species: Helianthus annuus, Nicotiana tabacum, and Vetiveria zizanioides for phytoaccumulation of Pb was studied. Plants were grown in hydroponic solution containing Pb(NO3)2 at concentration of 0.25 and 2.5 mM Pb in the presence or absence of chelating agents (EDTA or DTPA). Lead (Pb) transport and localization within the tissues of the plant species was determined using scanning electron microscope equipped with energy dispersive X-ray spectrometers (SEM-EDS). The addition of chelators increased Pb uptake as compared to plants grown in solution containing Pb alone. Lead taken up by the plant species were concentrated in both leaf and stem at the region of vascular bundles with greater amounts in the leaf portion. Lead granules were also found in the H. annuus root tissue from the epidermis layer to the central axis. After four weeks of growth a 23-fold increase in shoot Pb content for H. annuus and N. tabacum and 17-fold increase in shoot Pb for V. zizanioides resulted from plants grown in the 2.5 mM Pb-EDTA treatment. The higher Pb treatment (2.5 mM Pb containing EDTA) resulted in higher concentrations of Pb in plant tissue at the fourth week of exposure as compared to Pb treatment containing DTPA. Overall, Pb accumulation potential of H. annuus was greater than that of N. tabacum and V. zizanioides as indicated by the bioconcentration factor (171, 70, and 88, respectively). The highest measured Pb concentrations were found in H. annuus roots, stems, and leaves (2668, 843, and 3611 microg/g DW, respectively) grown in the 2.5 mM Pb-EDTA treatment. The addition of chelators caused some reduction in plant growth and biomass. Results showed that the three plant species tested have potential for use in phytoaccumulation of Pb since the Pb was concentrated in leaf and stem as compared to control plants. H. annuus however best meet the prerequisites for a hyperaccumulator plant and would have the potential for use in the restoration of

  1. Quantitation of isobaric phosphatidylcholine species in human plasma using a hybrid quadrupole linear ion-trap mass spectrometer.

    Science.gov (United States)

    Zacek, Petr; Bukowski, Michael; Rosenberger, Thad A; Picklo, Matthew

    2016-12-01

    Phosphatidylcholine (PC) species in human plasma are used as biomarkers of disease. PC biomarkers are often limited by the inability to separate isobaric PCs. In this work, we developed a targeted shotgun approach for analysis of isobaric and isomeric PCs. This approach is comprised of two MS methods: a precursor ion scanning (PIS) of mass m/z 184 in positive mode (PIS m/z +184) and MS(3) fragmentation in negative mode, both performed on the same instrument, a hybrid triple quadrupole ion-trap mass spectrometer. The MS(3) experiment identified the FA composition and the relative abundance of isobaric and sn-1, sn-2 positional isomeric PC species, which were subsequently combined with absolute quantitative data obtained by PIS m/z +184 scan. This approach was applied to the analysis of a National Institute of Standards and Technology human blood plasma standard reference material (SRM 1950). We quantified more than 70 PCs and confirmed that a majority are present in isobaric and isomeric mixtures. The FA content determined by this method was comparable to that obtained using GC with flame ionization detection, supporting the quantitative nature of this MS method. This methodology will provide more in-depth biomarker information for clinical and mechanistic studies.

  2. Simultaneous visualization of different genomes (J, JSt and St) in a Thinopyrum intermedium × Thinopyrum ponticum synthetic hybrid (Poaceae) and in its parental species by multicolour genomic in situ hybridization (mcGISH).

    Science.gov (United States)

    Kruppa, Klaudia; Molnár-Láng, Márta

    2016-01-01

    Multicolour genomic in situ hybridization (mcGISH) using total genomic DNA probes from Thinopyrum bessarabicum (Săvulescu & Rayss, 1923) Á. Löve, 1984 (genome J(b) or E(b), 2n = 14), and Pseudoroegneria spicata (Pursh, 1814) Á. Löve, 1980 (genome St, 2n = 14) was used to characterize the mitotic metaphase chromosomes of a synthetic hybrid of Thinopyrum intermedium (Host, 1805) Barkworth & D.R. Dewey, 1985 and Thinopyrum ponticum (Podpěra, 1902) Z.-W. Liu et R.-C.Wang, 1993 named "Agropyron glael" and produced by N.V. Tsitsin in the former Soviet Union. The mcGISH pattern of this synthetic hybrid was compared to its parental wheatgrass species. Hexaploid Thinopyrum intermedium contained 19 J, 9 J(St) and 14 St chromosomes. The three analysed Thinopyrum ponticum accessions had different chromosome compositions: 43 J + 27 J(St) (PI531737), 40 J + 30 J(St) (VIR-44486) and 38 J + 32 J(St) (D-3494). The synthetic hybrid carried 18 J, 28 J(St) and 8 St chromosomes, including one pair of J-St translocation and/or decreased fluorescent intensity, resulting in unique hybridization patterns. Wheat line Mv9kr1 was crossed with the Thinopyrum intermedium × Thinopyrum ponticum synthetic hybrid in Hungary in order to transfer its advantageous agronomic traits (leaf rust and yellow rust resistance) into wheat. The chromosome composition of a wheat/A.glael F1 hybrid was 21 wheat + 28 wheatgrass (11 J + 14 J(St)+ 3 S). In the present study, mcGISH involving the simultaneous use of St and J genomic DNA as probes provided information about the type of Thinopyrum chromosomes in a Thinopyrum intermedium/Thinopyrum ponticum synthetic hybrid called A. glael.

  3. 自然杂交对植物物种生存进化的影响%Effects of Natural Hybridization on Plant Species Survival and Evolution

    Institute of Scientific and Technical Information of China (English)

    闫晓慧; 胡世俊

    2012-01-01

    Natural hybridization is a common phenomenon, and the action of human being is accelerating the happenness of natural hy bridization, non-natural hybridization caused by human disturbance has great negative effects on species survival and evolution. We summarize the progress of hybridization and introgression based on the papers issused in recent years in this article. Hybridization not only affects species survival and evolution, but also bring some challenges to theory and practice of plant conservation. Hybridization and introgression has the potential to improve the genetic diversity, and can provide materials for species evolution, improve valuable variation for adaptation, and even lead to the formation of new ecotype or new species. But, small populations have tendency to go ex tinction when they hybridize with another species in greater amount. Natural hybridization challenges the definition of species concept. Hybridization can blur species boundary and promote the formation of " difficult" taxa in taxonomic and phylogenetic studies. Natural hybridization can promote evolutionary divergence between taxa by reinforcement of reproductive isolation, it can also lead to the break down of reproductive isolation and species mergence, and hence decrease the species diversity. We conclude that we should focus on the studies of isolation mechanisms, mechanisms of introgression, and how to prevent the negative effects of hybridization and introgres sion in the background of high rate of species invasion and extinction.%自然杂交是一个常见现象,人类活动正加速自然杂交的发生,人类干扰导致的非自然的杂交过程对物种的生存、进化产生许多负面影响,本文根据文献对近年来自然杂交方面的研究进行了综述.自然杂交不仅影响着物种的生存、进化,也对物种的保护问题带来许多理论上与实践上的挑战.杂交与遗传渗入有利于提高物种的遗传多样性,为物种的进化提供

  4. Rapid differentiation of Francisella species and subspecies by fluorescent in situ hybridization targeting the 23S rRNA

    Directory of Open Access Journals (Sweden)

    Trebesius Karlheinz

    2010-03-01

    Full Text Available Abstract Background Francisella (F. tularensis is the causative agent of tularemia. Due to its low infectious dose, ease of dissemination and high case fatality rate, F. tularensis was the subject in diverse biological weapons programs and is among the top six agents with high potential if misused in bioterrorism. Microbiological diagnosis is cumbersome and time-consuming. Methods for the direct detection of the pathogen (immunofluorescence, PCR have been developed but are restricted to reference laboratories. Results The complete 23S rRNA genes of representative strains of F. philomiragia and all subspecies of F. tularensis were sequenced. Single nucleotide polymorphisms on species and subspecies level were confirmed by partial amplification and sequencing of 24 additional strains. Fluorescent In Situ Hybridization (FISH assays were established using species- and subspecies-specific probes. Different FISH protocols allowed the positive identification of all 4 F. philomiragia strains, and more than 40 F. tularensis strains tested. By combination of different probes, it was possible to differentiate the F. tularensis subspecies holarctica, tularensis, mediasiatica and novicida. No cross reactivity with strains of 71 clinically relevant bacterial species was observed. FISH was also successfully applied to detect different F. tularensis strains in infected cells or tissue samples. In blood culture systems spiked with F. tularensis, bacterial cells of different subspecies could be separated within single samples. Conclusion We could show that FISH targeting the 23S rRNA gene is a rapid and versatile method for the identification and differentiation of F. tularensis isolates from both laboratory cultures and clinical samples.

  5. Phylogenetic analysis of subgenus vigna species using nuclear ribosomal RNA ITS: evidence of hybridization among Vigna unguiculata subspecies.

    Science.gov (United States)

    Vijaykumar, Archana; Saini, Ajay; Jawali, Narendra

    2010-01-01

    Molecular phylogeny among species belonging to subgenus Vigna (genus Vigna) was inferred based on internal transcribed spacer (ITS) sequences of 18S-5.8S-26S ribosomal RNA gene unit. Analysis showed a total of 356 polymorphic sites of which approximately 80% were parsimony informative. Phylogenetic reconstruction by neighbor joining and maximum parsimony methods placed the 57 Vigna accessions (belonging to 15 species) into 5 major clades. Five species viz. Vigna heterophylla, Vigna pubigera, Vigna parkeri, Vigna laurentii, and Vigna gracilis whose position in the subgenus was previously not known were placed in the section Vigna. A single accession (Vigna unguiculata ssp. tenuis, NI 1637) harbored 2 intragenomic ITS variants, indicative of 2 different types of ribosomal DNA (rDNA) repeat units. ITS variant type-I was close to ITS from V. unguiculata ssp. pubescens, whereas type-II was close to V. unguiculata ssp. tenuis. Transcript analysis clearly demonstrates that in accession NI 1637, rDNA repeat units with only type-II ITS variants are transcriptionally active. Evidence from sequence analysis (of 5.8S, ITS1, and ITS2) and secondary structure analysis (of ITS1 and ITS2) indicates that the type-I ITS variant probably does not belong to the pseudogenic rDNA repeat units. The results from phylogenetic and transcript analysis suggest that the rDNA units with the type-I ITS may have introgressed as a result of hybridization (between ssp. tenuis and ssp. pubescens); however, it has been epigenetically silenced. The results also demonstrate differential evolution of ITS sequence among wild and cultivated forms of V. unguiculata.

  6. Investigation on The Effect of Some Plant Growth Regulators on Sunflower ( Helianthus Annuus L.

    Directory of Open Access Journals (Sweden)

    T. Kolev

    2006-05-01

    Full Text Available With a view to establish the effect of some plant growth regulators on sunflower (Helianthus annuus L.production and oil content was made an experiment. The agricultural test was carried out in the experimentalbase of Agricultural University of Plovdiv, Bulgaria in 2001- 2003.The investigation was pulled out byblock design with four replications with crop plot size 20 m2, previously sowed with wheat. The testedchemicals are as follows plant growth regulators: “H- 40’’ (alfanaftilvinegar acid, “M-2’’ (amid ofdicarbonovy acids of benzolovid number, “31’’(derivate of naphthalene with auxin efficacy, “XP’’(ftalaminova acid content micro and macro elements, synthesised in Research Institute of Cryobiology andFood Technology, Sofia in dose 1 cm3 / l water and Agat 25 EK- 2.5 g/da (Too bio biz Ltd..The investigation was made on Bulgarian sunflower hybrid Super Start, treated during pinhead andflowering. The effect of the tested plant growth regulators on the quantity of yield and some structuralelements (sunflower heads number, seeds number, seeds mass, mass/ 1000 seeds, oil content and oil yieldwas reported in the process of investigation. The effect grade of growth regulators is fixed due to non-treatedcontrol.By the dispersal analysis method, it is made a mathematics processing of the values of received data. Theresults of investigation showed that there is no significantly difference between the seed yield kg/da and oilcontent l/da in pinhead period by the use of plant growth regulators - ‘‘31’’ (1cm3/l water and ‘’Agat 25EK’’ (2.5 g/ da. In the flowering period when treated with the same plant growth regulators, the seed yield isincreased as of 15.3 % and the oil content increased as of 16.4% (with Agat 25 EK but it is decreased as of18.6% by the application of “31”.

  7. Relevance of unilateral and bilateral sexual polyploidization in relation to intergenomic recombination and introgression in Lilium species hybrids

    NARCIS (Netherlands)

    Nadeem Khan, M.; Barba Gonzalez, R.; Ramanna, M.S.; Arens, P.F.P.; Visser, R.G.F.; Tuyl, van J.M.

    2010-01-01

    Sexual polyploids were induced in diploid (2n = 2x = 24) interspecific F1 hybrids of Longiflorum × Asiatic (LA) and Oriental × Asiatic (OA) Lilium hybrids by backcrossing to Asiatic (AA) parents as well as by sib-mating of the F1 LA hybrids. A majority of the BC1 progenies were triploid and the prog

  8. Boechera microsatellite website: an online portal for species identification and determination of hybrid parentage.

    Science.gov (United States)

    Li, Fay-Wei; Rushworth, Catherine A; Beck, James B; Windham, Michael D

    2017-01-01

    Boechera (Brassicaceae) has many features to recommend it as a model genus for ecological and evolutionary research, including species richness, ecological diversity, experimental tractability and close phylogenetic proximity to Arabidopsis . However, efforts to realize the full potential of this model system have been thwarted by the frequent inability of researchers to identify their samples and place them in a broader evolutionary context. Here we present the Boechera Microsatellite Website (BMW), a portal that archives over 55 000 microsatellite allele calls from 4471 specimens (including 133 nomenclatural types). The portal includes analytical tools that utilize data from 15 microsatellite loci as a highly effective DNA barcoding system. The BMW facilitates the accurate identification of Boechera samples and the investigation of reticulate evolution among the ±83 sexual diploid taxa in the genus, thereby greatly enhancing Boechera 's potential as a model system.

  9. Hybridization, natural selection, and evolution of reproductive isolation: a 25-years survey of an artificial sympatric area between two mosquito sibling species of the Aedes mariae complex.

    Science.gov (United States)

    Urbanelli, Sandra; Porretta, Daniele; Mastrantonio, Valentina; Bellini, Romeo; Pieraccini, Giuseppe; Romoli, Riccardo; Crasta, Graziano; Nascetti, Giuseppe

    2014-10-01

    Natural selection can act against maladaptive hybridization between co-occurring divergent populations leading to evolution of reproductive isolation among them. A critical unanswered question about this process that provides a basis for the theory of speciation by reinforcement, is whether natural selection can cause hybridization rates to evolve to zero. Here, we investigated this issue in two sibling mosquitoes species, Aedes mariae and Aedes zammitii, that show postmating reproductive isolation (F1 males sterile) and partial premating isolation (different height of mating swarms) that could be reinforced by natural selection against hybridization. In 1986, we created an artificial sympatric area between the two species and sampled about 20,000 individuals over the following 25 years. Between 1986 and 2011, the composition of mating swarms and the hybridization rate between the two species were investigated across time in the sympatric area. Our results showed that A. mariae and A. zammitii have not completed reproductive isolation since their first contact in the artificial sympatric area. We have discussed the relative role of factors such as time of contact, gene flow, strength of natural selection, and biological mechanisms causing prezygotic isolation to explain the observed results. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  10. The plant pathogen Phytophthora andina emerged via hybridization of an unknown Phytophthora species and the Irish potato famine pathogen, P. infestans.

    Science.gov (United States)

    Goss, Erica M; Cardenas, Martha E; Myers, Kevin; Forbes, Gregory A; Fry, William E; Restrepo, Silvia; Grünwald, Niklaus J

    2011-01-01

    Emerging plant pathogens have largely been a consequence of the movement of pathogens to new geographic regions. Another documented mechanism for the emergence of plant pathogens is hybridization between individuals of different species or subspecies, which may allow rapid evolution and adaptation to new hosts or environments. Hybrid plant pathogens have traditionally been difficult to detect or confirm, but the increasing ease of cloning and sequencing PCR products now makes the identification of species that consistently have genes or alleles with phylogenetically divergent origins relatively straightforward. We investigated the genetic origin of Phytophthora andina, an increasingly common pathogen of Andean crops Solanum betaceum, S. muricatum, S. quitoense, and several wild Solanum spp. It has been hypothesized that P. andina is a hybrid between the potato late blight pathogen P. infestans and another Phytophthora species. We tested this hypothesis by cloning four nuclear loci to obtain haplotypes and using these loci to infer the phylogenetic relationships of P. andina to P. infestans and other related species. Sequencing of cloned PCR products in every case revealed two distinct haplotypes for each locus in P. andina, such that each isolate had one allele derived from a P. infestans parent and a second divergent allele derived from an unknown species that is closely related but distinct from P. infestans, P. mirabilis, and P. ipomoeae. To the best of our knowledge, the unknown parent has not yet been collected. We also observed sequence polymorphism among P. andina isolates at three of the four loci, many of which segregate between previously described P. andina clonal lineages. These results provide strong support that P. andina emerged via hybridization between P. infestans and another unknown Phytophthora species also belonging to Phytophthora clade 1c.

  11. The plant pathogen Phytophthora andina emerged via hybridization of an unknown Phytophthora species and the Irish potato famine pathogen, P. infestans.

    Directory of Open Access Journals (Sweden)

    Erica M Goss

    Full Text Available Emerging plant pathogens have largely been a consequence of the movement of pathogens to new geographic regions. Another documented mechanism for the emergence of plant pathogens is hybridization between individuals of different species or subspecies, which may allow rapid evolution and adaptation to new hosts or environments. Hybrid plant pathogens have traditionally been difficult to detect or confirm, but the increasing ease of cloning and sequencing PCR products now makes the identification of species that consistently have genes or alleles with phylogenetically divergent origins relatively straightforward. We investigated the genetic origin of Phytophthora andina, an increasingly common pathogen of Andean crops Solanum betaceum, S. muricatum, S. quitoense, and several wild Solanum spp. It has been hypothesized that P. andina is a hybrid between the potato late blight pathogen P. infestans and another Phytophthora species. We tested this hypothesis by cloning four nuclear loci to obtain haplotypes and using these loci to infer the phylogenetic relationships of P. andina to P. infestans and other related species. Sequencing of cloned PCR products in every case revealed two distinct haplotypes for each locus in P. andina, such that each isolate had one allele derived from a P. infestans parent and a second divergent allele derived from an unknown species that is closely related but distinct from P. infestans, P. mirabilis, and P. ipomoeae. To the best of our knowledge, the unknown parent has not yet been collected. We also observed sequence polymorphism among P. andina isolates at three of the four loci, many of which segregate between previously described P. andina clonal lineages. These results provide strong support that P. andina emerged via hybridization between P. infestans and another unknown Phytophthora species also belonging to Phytophthora clade 1c.

  12. Post-anthesis development of oil content and composition with respect to seed moisture in two high-oleic sunflower hybrids in the northern US

    Science.gov (United States)

    Desiccating sunflower (Helianthus annuus L.) at physiological maturity (PM) or as early as possible can be used to hasten harvest and thus, reduce yield loss associated with severe weather, plant degradation, and bird predation. Previous work showed that two modern oilseed sunflower hybrids studied ...

  13. Photogenerated charge carriers and reactive oxygen species in ZnO/Au hybrid nanostructures with enhanced photocatalytic and antibacterial activity.

    Science.gov (United States)

    He, Weiwei; Kim, Hyun-Kyung; Wamer, Wayne G; Melka, David; Callahan, John H; Yin, Jun-Jie

    2014-01-15

    Semiconductor nanostructures with photocatalytic activity have the potential for many applications including remediation of environmental pollutants and use in antibacterial products. An effective way for promoting photocatalytic activity is depositing noble metal nanoparticles (NPs) on a semiconductor. In this paper, we demonstrated the successful deposition of Au NPs, having sizes smaller than 3 nm, onto ZnO NPs. ZnO/Au hybrid nanostructures having different molar ratios of Au to ZnO were synthesized. It was found that Au nanocomponents even at a very low Au/ZnO molar ratio of 0.2% can greatly enhance the photocatalytic and antibacterial activity of ZnO. Electron spin resonance spectroscopy with spin trapping and spin labeling was used to investigate the enhancing effect of Au NPs on the generation of reactive oxygen species and photoinduced charge carriers. Deposition of Au NPs onto ZnO resulted in a dramatic increase in light-induced generation of hydroxyl radical, superoxide and singlet oxygen, and production of holes and electrons. The enhancing effect of Au was dependent on the molar ratio of Au present in the ZnO/Au nanostructures. Consistent with these results from ESR measurements, ZnO/Au nanostructures also exhibited enhanced photocatalytic and antibacterial activity. These results unveiled the enhanced mechanism of Au on ZnO and these materials have great potential for use in water purification and antibacterial products.

  14. Dielectrophoresis and shear-enhanced sensitivity and selectivity of DNA hybridization for the rapid discrimination of Candida species.

    Science.gov (United States)

    Cheng, I-Fang; Han, Huan-Wen; Chang, Hsien-Chang

    2012-03-15

    We present a dielectrophoresis (DEP)-based microfluidic chip that is capable of enhancing the sensitivity and selectivity of DNA hybridization using an AC electric field and hydrodynamic shear in a continuous through-flow. Molecular DEP was employed to rapidly trap ssDNA molecules in a flowing solution to a cusp-shaped nanocolloid assembly on a microfluidic chip with a locally amplified AC electric field gradient. The detection time can be accelerated to sub-minute periods, and the sensitivity can reach the pico-molar level due to the AC DEP-enhanced molecule concentration (at an optimal AC frequency of 900 kHz) in a small region (∼100 μm(2)) instead of the broad area used in a tank reactor (∼10(6) μm(2)). Continuous flow in a microchannel provides a constant and high shear rate that can shear off most non-specific target-probe binding to promote the discriminating selectivity. On-chip multi-target discrimination of Candida species can be achieved within a few minutes under optimal conditions.

  15. Greenhouse evaluation of EDTA effectiveness at enhancing Cd, Cr, and Ni uptake in Helianthus annuus and Thlaspi caerulescens

    Energy Technology Data Exchange (ETDEWEB)

    Munn, J.; January, M.; Cutright, T.J. [Dept. Civil Engineering, The Univ. of Akron, OH (United States)

    2008-04-15

    Background, aims and scope. Phytoremediation is a promising means for the treatment of heavy metal contamination. Although several species have been identified as hyperaccumulators, most studies have been conducted with only one metal. Experiments were conducted to investigate the ability of Helianthus annuus and Thlaspi caerulescens to simultaneously uptake Cd, Cr and Ni. Materials and methods. The efficiency of plants grown in a sandy-loam soil was investigated. The ability of two EDTA concentrations (0.1 and 0.3 g kg{sup -1}) for enhancing the phytoremediation of Cd, Cr and Ni at two different metal concentrations (24.75 mg kg{sup -1} and 90 mg kg{sup -1}) was studied. Results. Thlaspi hyperaccumulated Ni with 0.1 g kg{sup -1} EDTA. When the EDTA dosage was increased to 0.3 g kg{sup -1}, Thlaspi was able to hyperaccumulate both Ni and Cr. Since Thlaspi is a low-biomass plant, it was considered insufficient for full-scale applications. Helianthus annuus hyperacummulated Cr (with 0.1 g kg{sup -1} EDTA) and Cd (0.3 g kg{sup -1} EDTA). Discussion. When the contamination was 8.25 mg kg{sup -1} per metal, the total metal uptake was 10-25% (1.35 to 2.12 mg) higher and had the same uptake selectivity (Cr>>Cd>Ni) for both EDTA levels. It was hypothesized that complexation with EDTA interfered with Ni translocation. For these experiments, the optimal results were obtained with the H. annuus-0.1 g kg{sup -1} EDTA combination. Conclusions. Although the use of EDTA did increase the amount of metal that could be extracted, care should be taken during in-situ field applications. Chelators can also increase the amount of metals that are leached past the root zone. Metal leaching and subsequent migration could lead to ground water contamination as well as lead to new soil contamination. Recommendations and perspectives. Additional research to identify the optimal EDTA dosage for field applications is warranted. This is necessary to ensure that the metals do not leach past the

  16. New habitats, new menaces: Centaurea x kleinii (C. moncktonii x C. solstitialis, a new hybrid species between two alien weeds

    Directory of Open Access Journals (Sweden)

    Susanna, A.

    2010-12-01

    Full Text Available Anthropic alteration of habitat opens the door to the cohabitation of imported species that in their native range would never coexist. Centaurea solstitialis and Centaurea moncktonii are two invasive species whose natural distributions in Eurasia do not overlap. After introduction in North America, invasive spread led to overlapping distributions. Although the environmental requirements differ between the two species, the close proximity of diverse habitats (within pollinator range has resulted in several cases of natural hybridization between the two. The result of the cross between these two distantly related species is a sterile perennial. Many of its characteristics are intermediate between its parents, but morphologically it is closer to Centaurea moncktonii (probably the maternal parent, and itself of hybrid origin. The plant could possibly become an invasive weed through clonal reproduction. The apparent maternal parent, which the hybrid may more closely resemble physiologically as well as morphologically, is a wellknown creeping weed in alpine pastures throughout Europe.La alteración antrópica del hábitat da paso a la cohabitación de especies importadas que nunca coexistirían en su ámbito natural. Centaurea solstitialis y Centaurea moncktonii son dos especies invasoras cuyas distribuciones en Eurasia apenas se solapan. Después de su introducción en Norteamérica, la expansión invasiva condujo a distribuciones superpuestas. Aunque los requerimientos ambientales de las dos especies son distintos, la proximidad de hábitats diversos (dentro del alcance de los polinizadores ha dado lugar a varios casos de hibridación natural entre ambas. El cruce resultante entre dos especies lejanamente emparentadas es una planta perenne estéril. Muchos de los caracteres del híbrido son intermedios entre sus especies parentales, pero morfológicamente es más parecida a Centaurea moncktonii (probablemente la especie materna y a su vez ya de

  17. Secondary structure of oleosins in oil bodies isolated from seeds of safflower (Carthamus tinctorius L.) and sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Lacey, D J; Wellner, N; Beaudoin, F; Napier, J A; Shewry, P R

    1998-09-01

    Oil bodies were isolated from mature seeds of sunflower (Helianthus annuus L.) and safflower (Carthamus tinctorius L.). Oil body preparations containing only oleosin proteins could be obtained from safflower seeds by salt-washing followed by centrifugation on discontinuous sucrose density gradients. However, it was necessary to treat sunflower oil bodies with urea to obtain preparations of similar purity. Incubation of the oil bodies with proteinases gave two fragments with molecular masses of 6 and 8 kDa which were protected from digestion. These fragments represented the hydrophobic domain of the oleosins, as determined by N-terminal sequencing. Intact and proteinase-treated oil bodies of both species were analysed by Fourier-transform infrared spectroscopy, as dry films and in aqueous medium, the spectra being compared with those obtained for pure oil samples in order to identify the bands resulting from the oleosin proteins and protected peptides. This investigation showed that the hydrophobic domain of the oleosins in intact oil bodies is predominantly alpha-helical in structure and that the conformation was not greatly affected by washing the oil bodies with urea during preparation.

  18. Modelled hydraulic redistribution by sunflower (Helianthus annuus L.) matches observed data only after including night-time transpiration.

    Science.gov (United States)

    Neumann, Rebecca B; Cardon, Zoe G; Teshera-Levye, Jennifer; Rockwell, Fulton E; Zwieniecki, Maciej A; Holbrook, N Michele

    2014-04-01

    The movement of water from moist to dry soil layers through the root systems of plants, referred to as hydraulic redistribution (HR), occurs throughout the world and is thought to influence carbon and water budgets and ecosystem functioning. The realized hydrologic, biogeochemical and ecological consequences of HR depend on the amount of redistributed water, whereas the ability to assess these impacts requires models that correctly capture HR magnitude and timing. Using several soil types and two ecotypes of sunflower (Helianthus annuus L.) in split-pot experiments, we examined how well the widely used HR modelling formulation developed by Ryel et al. matched experimental determination of HR across a range of water potential driving gradients. H. annuus carries out extensive night-time transpiration, and although over the last decade it has become more widely recognized that night-time transpiration occurs in multiple species and many ecosystems, the original Ryel et al. formulation does not include the effect of night-time transpiration on HR. We developed and added a representation of night-time transpiration into the formulation, and only then was the model able to capture the dynamics and magnitude of HR we observed as soils dried and night-time stomatal behaviour changed, both influencing HR.

  19. Modeled hydraulic redistribution by Helianthus annuus L. matches observed data only after model modification to include nighttime transpiration

    Science.gov (United States)

    Neumann, R. B.; Cardon, Z. G.; Rockwell, F. E.; Teshera-Levye, J.; Zwieniecki, M.; Holbrook, N. M.

    2013-12-01

    The movement of water from moist to dry soil layers through the root systems of plants, referred to as hydraulic redistribution (HR), occurs throughout the world and is thought to influence carbon and water budgets and ecosystem functioning. The realized hydrologic, biogeochemical, and ecological consequences of HR depend on the amount of redistributed water, while the ability to assess these impacts requires models that correctly capture HR magnitude and timing. Using several soil types and two eco-types of Helianthus annuus L. in split-pot experiments, we examined how well the widely used HR modeling formulation developed by Ryel et al. (2002) could match experimental determination of HR across a range of water potential driving gradients. H. annuus carries out extensive nighttime transpiration, and though over the last decade it has become more widely recognized that nighttime transpiration occurs in multiple species and many ecosystems, the original Ryel et al. (2002) formulation does not include the effect of nighttime transpiration on HR. We developed and added a representation of nighttime transpiration into the formulation, and only then was the model able to capture the dynamics and magnitude of HR we observed as soils dried and nighttime stomatal behavior changed, both influencing HR.

  20. Dyella thiooxydans sp. nov., a facultatively chemolithotrophic, thiosulfate-oxidizing bacterium isolated from rhizosphere soil of sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Anandham, Rangasamy; Kwon, Soon-Wo; Indira Gandhi, Pandiyan; Kim, Soo-Jin; Weon, Hang-Yeon; Kim, Yi-Seul; Sa, Tong-Min; Kim, Yong-Ki; Jee, Hyeong-Jin

    2011-02-01

    A Gram-negative, aerobic, motile, rod-shaped, thiosulfate-oxidizing bacterium, designated ATSB10(T), was isolated from rhizosphere soil of sunflower (Helianthus annuus L.). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain ATSB10(T) was closely related to members of the genera Dyella (96.4-98.1 % 16S rRNA gene sequence similarity) and Luteibacter (96.4-97.0 %) and Fulvimonas soli LMG 19981(T) (96.7 %) and Frateuria aurantia IFO 3245(T) (97.8 %). The predominant fatty acids were iso-C(16 : 0), iso-C(17 : 1)ω9c and iso-C(15 : 0). The major quinone was Q-8. The G+C content of the genomic DNA was 66.0 mol%. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidyldimethylethanolamine, an unknown phospholipid, unknown aminophospholipids and an unknown aminolipid. On the basis of phenotypic properties, phylogenetic distinctiveness and DNA-DNA relatedness, strain ATSB10(T) represents a novel species in the genus Dyella, for which the name Dyella thiooxydans sp. nov. is proposed. The type strain is ATSB10(T) (=KACC 12756(T) =LMG 24673(T)).

  1. Identification and characterization of two bisabolene synthases from linear glandular trichomes of sunflower (Helianthus annuus L., Asteraceae).

    Science.gov (United States)

    Aschenbrenner, Anna-Katharina; Kwon, Moonhyuk; Conrad, Jürgen; Ro, Dae-Kyun; Spring, Otmar

    2016-04-01

    Sunflower is known to produce a variety of bisabolene-type sesquiterpenes and accumulates these substances in trichomes of leaves, stems and flowering parts. A bioinformatics approach was used to identify the enzyme responsible for the initial step in the biosynthesis of these compounds from its precursor farnesyl pyrophosphate. Based on sequence similarity with a known bisabolene synthases from Arabidopsis thaliana AtTPS12, candidate genes of Helianthus were searched in EST-database and used to design specific primers. PCR experiments identified two candidates in the RNA pool of linear glandular trichomes of sunflower. Their sequences contained the typical motifs of sesquiterpene synthases and their expression in yeast functionally characterized them as bisabolene synthases. Spectroscopic analysis identified the stereochemistry of the product of both enzymes as (Z)-γ-bisabolene. The origin of the two sunflower bisabolene synthase genes from the transcripts of linear trichomes indicates that they may be involved in the synthesis of sesquiterpenes produced in these trichomes. Comparison of the amino acid sequences of the sunflower bisabolene synthases showed high similarity with sesquiterpene synthases from other Asteracean species and indicated putative evolutionary origin from a β-farnesene synthase.

  2. Characterization of a small acyl-CoA-binding protein (ACBP) from Helianthus annuus L. and its binding affinities.

    Science.gov (United States)

    Aznar-Moreno, Jose A; Venegas-Calerón, Mónica; Du, Zhi-Yan; Garcés, Rafael; Tanner, Julian A; Chye, Mee-Len; Martínez-Force, Enrique; Salas, Joaquín J

    2016-05-01

    Acyl-CoA-binding proteins (ACBPs) bind to acyl-CoA esters and promote their interaction with other proteins, lipids and cell structures. Small class I ACBPs have been identified in different plants, such as Arabidopsis thaliana (AtACBP6), Brassica napus (BnACBP) and Oryza sativa (OsACBP1, OsACBP2, OsACBP3), and they are capable of binding to different acyl-CoA esters and phospholipids. Here we characterize HaACBP6, a class I ACBP expressed in sunflower (Helianthus annuus) tissues, studying the specificity of its corresponding recombinant HaACBP6 protein towards various acyl-CoA esters and phospholipids in vitro, particularly using isothermal titration calorimetry and protein phospholipid binding assays. This protein binds with high affinity to de novo synthetized derivatives palmitoly-CoA, stearoyl-CoA and oleoyl-CoA (Kd 0.29, 0.14 and 0.15 μM respectively). On the contrary, it showed lower affinity towards linoleoyl-CoA (Kd 5.6 μM). Moreover, rHaACBP6 binds to different phosphatidylcholine species (dipalmitoyl-PC, dioleoyl-PC and dilinoleoyl-PC), yet it displays no affinity towards other phospholipids like lyso-PC, phosphatidic acid and lysophosphatidic acid derivatives. In the light of these results, the possible involvement of this protein in sunflower oil synthesis is considered.

  3. Homoploid hybrid expectations

    Science.gov (United States)

    Homoploid hybrid speciation occurs when a stable, fertile, and reproductively isolated lineage results from hybridization between two distinct species without a change in ploidy level. Reproductive isolation between a homoploid hybrid species and its parents is generally attained via chromosomal re...

  4. Efecto protector de Helianthus annuus (girasol sobre el infarto de miocardio en conejos Nueva Zelanda

    Directory of Open Access Journals (Sweden)

    Edith Guardia-Espinoza

    Full Text Available Objetivos. Determinar el efecto protector del aceite de Helianthus annuus (Girasol sobre el infarto de miocardio inducido con epinefrina en conejos Nueva Zelanda. Materiales y métodos. Los conejos fueron asignados aleatoriamente en cinco grupos (n= 8 por grupo: blanco, control negativo, experimental 1 (10 mg/kg, experimental 2 (20 mg/kg y experimental 3 (40 mg/kg. Los grupos experimentales 1, 2 y 3 recibieron aceite de Helianthus annuus durante dos semanas. La epinefrina (2 mg/Kg se administró a los grupos control negativo, experimentales 1, 2 y 3 durante dos días consecutivos con un intervalo de 24 h después del pretratamiento con aceite. Veinticuatro horas después de la última administración, los conejos fueron anestesiados y sacrificados. Se evaluaron los niveles séricos de troponina I y número de polimorfonucleares por μm2. Resultados. Se encontró diferencia significativa entre el grupo control negativo y los grupos experimentales 1, 2 y 3 en los variables niveles séricos de troponina I y número de polimorfonucleares por μm2. Conclusiones: El aceite de Helianthus annuus a dosis de 20 mg/kg tiene efecto protector sobre el infarto de miocardio inducido con epinefrina en conejos Nueva Zelanda

  5. Efecto protector de Helianthus annuus (girasol sobre el infarto de miocardio en conejos Nueva Zelanda

    Directory of Open Access Journals (Sweden)

    Edith Guardia-Espinoza

    Full Text Available Objetivos. Determinar el efecto protector del aceite de Helianthus annuus (Girasol sobre el infarto de miocardio inducido con epinefrina en conejos Nueva Zelanda. Materiales y métodos. Los conejos fueron asignados aleatoriamente en cinco grupos (n= 8 por grupo: blanco, control negativo, experimental 1 (10 mg/kg, experimental 2 (20 mg/kg y experimental 3 (40 mg/kg. Los grupos experimentales 1, 2 y 3 recibieron aceite de Helianthus annuus durante dos semanas. La epinefrina (2 mg/Kg se administró a los grupos control negativo, experimentales 1, 2 y 3 durante dos días consecutivos con un intervalo de 24 h después del pretratamiento con aceite. Veinticuatro horas después de la última administración, los conejos fueron anestesiados y sacrificados. Se evaluaron los niveles séricos de troponina I y número de polimorfonucleares por μm2. Resultados. Se encontró diferencia significativa entre el grupo control negativo y los grupos experimentales 1, 2 y 3 en los variables niveles séricos de troponina I y número de polimorfonucleares por μm2. Conclusiones: El aceite de Helianthus annuus a dosis de 20 mg/kg tiene efecto protector sobre el infarto de miocardio inducido con epinefrina en conejos Nueva Zelanda

  6. Multiple-geographic-scale genetic structure of two mangrove tree species: the roles of mating system, hybridization, limited dispersal and extrinsic factors.

    Directory of Open Access Journals (Sweden)

    Gustavo M Mori

    Full Text Available Mangrove plants comprise a unique group of organisms that grow within the intertidal zones of tropical and subtropical regions and whose distributions are influenced by both biotic and abiotic factors. To understand how these extrinsic and intrinsic processes influence a more fundamental level of the biological hierarchy of mangroves, we studied the genetic diversity of two Neotropical mangrove trees, Avicenniagerminans and A. schaueriana, using microsatellites markers. As reported for other sea-dispersed species, there was a strong differentiation between A. germinans and A. schaueriana populations sampled north and south of the northeastern extremity of South America, likely due to the influence of marine superficial currents. Moreover, we observed fine-scale genetic structures even when no obvious physical barriers were present, indicating pollen and propagule dispersal limitation, which could be explained by isolation-by-distance coupled with mating system differences. We report the first evidence of ongoing hybridization between Avicennia species and that these hybrids are fertile, although this interspecific crossing has not contributed to an increase in the genetic diversity the populations where A. germinans and A. schaueriana hybridize. These findings highlight the complex interplay between intrinsic and extrinsic factors that shape the distribution of the genetic diversity in these sea-dispersed colonizer species.

  7. Depletion of Abundant Sequences by Hybridization (DASH): using Cas9 to remove unwanted high-abundance species in sequencing libraries and molecular counting applications.

    Science.gov (United States)

    Gu, W; Crawford, E D; O'Donovan, B D; Wilson, M R; Chow, E D; Retallack, H; DeRisi, J L

    2016-03-04

    Next-generation sequencing has generated a need for a broadly applicable method to remove unwanted high-abundance species prior to sequencing. We introduce DASH (Depletion of Abundant Sequences by Hybridization). Sequencing libraries are 'DASHed' with recombinant Cas9 protein complexed with a library of guide RNAs targeting unwanted species for cleavage, thus preventing them from consuming sequencing space. We demonstrate a more than 99 % reduction of mitochondrial rRNA in HeLa cells, and enrichment of pathogen sequences in patient samples. We also demonstrate an application of DASH in cancer. This simple method can be adapted for any sample type and increases sequencing yield without additional cost.

  8. Resource allocation among sexual, clonal reproduction and vegetative growth of two Potamogeton species and their hybrid:Adaptability of the hybrid in relation to its parents

    Institute of Scientific and Technical Information of China (English)

    Fan LIU; Xiao-Lin ZHANG; Qing-Feng WANG; Hui LIU; Guang-Xi WANG; Wei LI

    2013-01-01

    Resource allocation,as well as the tradeoffs among different reproductive components,plays an important role in the adaptability of plants to different environments.The hybrid may exhibit a higher adaptability in life history in heterogeneous environments because of the genetic variation derived from its parents.In this study,we exploited three levels of water depths and two types of sediments to investigate the resource allocation pattern of the first generation of the natural hybrid Potamogeton × intortifolius compared to its parents P.wrightii and P.perfoliatus.We also measured the ramet survivorship and the seed set of the hybrid P.× intortifolius.Our results showed that P.×intortifolius had higher ramet survival than its parents at 1.5-m water depth on clay sediment.The possible tradeoffs showed that in P.×intortifolius the tradeoff pattern between sexual and clonal reproduction was more pronounced in limiting environments.The individuals allocated more resources to sexual reproduction when the environment was limiting,which might confer a higher ability to utilize resources,to produce offspring and to found new populations.Although the seed set of P.×intortifolius was lower than its parents,it had a higher ability to increase its seed set when the environment was limiting (sandy sediment) than its parents,which might benefit its future survival.These results indicated that the F1 hybrid P.×intortifolius was more able to adapt to limiting environments than one or both of its two parental taxa.

  9. Influence of temperature and moisture conditions of locality on the yield formation of sunflower (Helianthus annuus L.

    Directory of Open Access Journals (Sweden)

    Ivan Černý

    2011-01-01

    Full Text Available Field polyfactorial experiments were realized on fields of the Agricultural Co-operative in Nitrianska Blatnica in years 2007−2009. Experimental field is located in the maize production area (climatic region: warm; climatic sub region dry; climatic zone: warm, dry with mild winter and long sunshine in altitude 250 m above sea level, with brown soil. We observed the influence of both temperature and moisture conditions of experimental area on sunflower yield of achenes (conventional, medium-late hybrids: NK Brio, NK Armoni. Preceding crop of sunflower (Helianthus annuus L. every experimental year was wheat (Triticum aestivum L.. Technological system of sunflower cultivation was realized in accordance with conventional technology of cultivation. The basic fertilization was made by balance method on the base of agrochemical soil analysis for expected yield 3 t.ha−1. The meteorological data were got out from agrometeorological station of the Central Controlling and Testing Institute in Agriculture in Veľké Ripňany. During every experimental year the change of inner energy (ΔU was evaluated for thermodynamic characteristic analysis (security of the temperature and moisture and the impact of changes on yield forming with maximal yield (Ymax in 2008 and minimal yield (Ymin in 2009. Achieved value of yield from thermal and precipitation energy introduces concrete energy amount, which is available in given period for concrete height of yield. From the results follow, the sunflower has got critical thermodynamic phase in the period of months from July to August. For the yield formation is requirement, that input power of precipitation prevailed over the thermal during moths July to August. Achieved results confirmed statistically high significant dependence of the yield on weather conditions and for high annual variations in climatic characteristics the consideration is needed about potential changes some agrotechnological measures of

  10. Comparisons of ectomycorrhizal colonization of transgenic american chestnut with those of the wild type, a conventionally bred hybrid, and related fagaceae species.

    Science.gov (United States)

    D'Amico, Katherine M; Horton, Thomas R; Maynard, Charles A; Stehman, Stephen V; Oakes, Allison D; Powell, William A

    2015-01-01

    American chestnut (Castanea dentata [Marsh.] Borkh.) dominated the eastern forests of North America, serving as a keystone species both ecologically and economically until the introduction of the chestnut blight, Cryphonectria parasitica, functionally eradicated the species. Restoration efforts include genetic transformation utilizing genes such as oxalate oxidase to produce potentially blight-resistant chestnut trees that could be released back into the native range. However, before such a release can be undertaken, it is necessary to assess nontarget impacts. Since oxalate oxidase is meant to combat a fungal pathogen, we are particularly interested in potential impacts of this transgene on beneficial fungi. This study compares ectomycorrhizal fungal colonization on a transgenic American chestnut clone expressing enhanced blight resistance to a wild-type American chestnut, a conventionally bred American-Chinese hybrid chestnut, and other Fagaceae species. A greenhouse bioassay used soil from two field sites with different soil types and land use histories. The number of colonized root tips was counted, and fungal species were identified using morphology, restriction fragment length polymorphism (RFLP), and DNA sequencing. Results showed that total ectomycorrhizal colonization varied more by soil type than by tree species. Individual fungal species varied in their colonization rates, but there were no significant differences between colonization on transgenic and wild-type chestnuts. This study shows that the oxalate oxidase gene can increase resistance against Cryphonectria parasitica without changing the colonization rate for ectomycorrhizal species. These findings will be crucial for a potential deregulation of blight-resistant American chestnuts containing the oxalate oxidase gene.

  11. Cape heaths in European gardens: the early history of South African Erica species in cultivation, their deliberate hybridization and the orthographic bedlam

    Directory of Open Access Journals (Sweden)

    E. C. Nelson

    2004-12-01

    Full Text Available This paper discusses the horticultural history of southern African Erica spp. in Europe, and especially in Britain, during the late eighteenth and the early decades of the nineteenth century . We note evidence for the deliberate hybridization of the so-called Cape heaths by European horticulturists, in particular by the English nursery man William Rollisson and by the Very Rev. William Herbert. We discuss some of the nomenclatural consequences of the naming by miscellaneous botanists and nurserymen of the hundreds of new Erica species and hybrids, emphasizing the proliferation of eponyms. An appendix tabulates eponyms and their numerous orthographic variants published before 1835 within Erica, and provides the correct orthography for these epithets.

  12. Simultaneous detection of Anaplasma and Ehrlichia species in ruminants and detection of Ehrlichia ruminantium in Amblyomma variegatum ticks by reverse line blot hybridization.

    Science.gov (United States)

    Bekker, Cornelis P J; de Vos, Sander; Taoufik, Amar; Sparagano, Olivier A E; Jongejan, Frans

    2002-10-22

    The detection of Anaplasma and Ehrlichia species is usually based on species-specific PCR assays, since no assay is yet available which can detect and identify these species simultaneously. To this end, we developed a reverse line blot (RLB) assay for simultaneous detection and identification of Anaplasma and Ehrlichia species in domestic ruminants and ticks. In a PCR the hypervariable V1 region of the 16S ribosomal RNA (rRNA) gene was amplified with a set of primers unique for members of the genera Anaplasma and Ehrlichia [Int. J. Syst. Evol. Microbiol. 51 (2001) 2145]. Amplified PCR products from blood of domestic ruminants or Amblyomma variegatum tick samples were hybridized onto a membrane to which eight species-specific oligonucleotide probes and one Ehrlichia and Anaplasma catch-all oligonucleotide probe were covalently linked. No DNA was amplified from uninfected blood, nor from other hemoparasites such as Theileria annulata, or Babesia bigemina. The species-specific probes did not cross-react with DNA amplified from other species. E. ruminantium, A. ovis and another Ehrlichia were identified by RLB in blood samples collected from small ruminants in Mozambique. Finally, A. variegatum ticks were tested after feeding on E. ruminantium infected sheep. E. ruminantium could be detected in adult ticks even if feeding of nymphs was carried out 3.5 years post-infection. In conclusion, the developed species-specific oligonucleotide probes used in an RLB assay can simultaneously detect and identify several Ehrlichia and Anaplasma species. However, as no quantitative data for the detection limit are available yet, only positive results are interpretable at this stage.

  13. Serpocaulon × manizalense: a new hybrid between simple- and pinnate-leaved species of Serpocaulon (Polypodiaceae) from Colombia

    NARCIS (Netherlands)

    Sanín, D.; Torrez, V.

    2014-01-01

    During a revision of Serpocaulon from Colombia, a new hybrid was found between S. adnatum and S. levigatum near to Manizales city, which is described and illustrated herein. Qualitative and quantitative spore and macro-morphological characters were evaluated using principal component analyses to dis

  14. Neue Cytochrom P450 Enzyme des Sesquiterpenlacton Stoffwechsels der Sonnenblume (Helianthus annuus L.)

    OpenAIRE

    Frey, Maximilian

    2016-01-01

    In der vorliegenden Arbeit konnten der Aufklärung des Biosyntheseweges des Sesquiterpen-Metabolismus der Sonnenblume (Helianthus annuus) entscheidende Schritte hinzugefügt werden. Hierzu wurden zunächst aus einer Transkriptom Datenbank Kandidaten Sequenzen anhand von Expressions-Mustern und Ähnlichkeit zu bekannten, an STL-Stoffwechselwegen beteiligten P450-Enzymen gesucht. Mithilfe von 3´- und 5´-RACE-PCR wurden die offenen Leserahmen der Kandidaten aufgeklärt. Die anhand dieses Verfahrens a...

  15. Structure of the stigma and style in sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Gotelli, M M; Galati, B G; Medan, D

    2010-12-01

    This is the first report of the ultrastructure of the stigma and style during and after anthesis in Helianthus annuus L. using light and transmission electron microscopy. The stigma is bifid with unicellular papillae. There is no secretion of lipids, carbohydrates or proteins at anthesis. The style is semisolid in the upper portion, closer to the stigma, and becomes solid below. Ultrastructural changes on cells of the stigma and the style are described. The transmitting tissue of the ovule is first evident 40 minutes after pollination and persists during the first stages of embryogenesis. Only one pollen tube per micropyle was observed growing through this tissue.

  16. Genotoxic effects of the insecticide cypermethrin on the root meristem cells of sunflowers (Helianthus annuus L.).

    Science.gov (United States)

    Inceer, Huseyin; Hayirlioglu-Ayaz, Sema; Ozcan, Melahat

    2009-11-01

    In this study, the genotoxic effects of the insecticide cypermethrin on the root meristem cells of sunflowers (Helianthus annuus L.) were investigated. The roots were treated with 10- 25- 50- and 100-ppm concentrations of cypermethrin for 6, 12 and 24 h. The mitotic index and mitotic abnormalities were determined in both control and test groups. The cypermethrin showed a marked mitodepressive action on mitosis. The types of mitotic abnormalities included disturbed metaphase, c-mitosis, stickiness, laggards and chromatid bridges. A pronounced toxic effect was observed at the 50-ppm concentration. Cypermethrin may have genotoxic effects on sunflowers.

  17. Suppression subtractive hybridization reveals differential gene expression in sunflower grown in high P.

    Science.gov (United States)

    Padmanabhan, Priya; Sahi, Shivendra V

    2011-06-01

    Sunflower (Helianthus annuus L.) is a commercially important oilseed crop. Previous studies proved that this crop is a promising plant species for phytoextraction of excess soil phosphorus (P) because of its superior P accumulating characteristics. Suppression subtractive hybridization (SSH) strategy was employed to isolate and characterize genes that are induced in response to high P in this crop. SSH library was prepared using cDNA generated from plants treated with high P as the 'tester'. Based on the results of dot blot analysis, 360 positive cDNA clones were selected from the SSH library for sequencing. A total of 89 non-redundant expressed sequence tags (ESTs) were identified as high P-responsive genes and they were classified into 6 functional groups. Several genes involved in metabolism showed markedly preferential expression in the library. For further confirmation, thirteen of the representative ESTs were selected from all categories for RT-PCR analysis and the results showed up-regulation of these genes in response to high P-treatment. The gene expression data derived from this study suggested that several of the up-regulated genes identified under high P-treatment might be involved in P-accumulation and tolerance in this plant.

  18. Bioaugmentation with cadmium-resistant plant growth-promoting rhizobacteria to assist cadmium phytoextraction by Helianthus annuus.

    Science.gov (United States)

    Prapagdee, Benjaphorn; Chanprasert, Maesinee; Mongkolsuk, Skorn

    2013-07-01

    Micrococcus sp. MU1 and Klebsiella sp. BAM1, the cadmium-resistant plant growth-promoting rhizobacteria (PGPR), produce high levels of indole-3-acetic acid (IAA) during the late stationary phase of their growth. The ability of PGPR to promote root elongation, plant growth and cadmium uptake in sunflowers (Helianthus annuus) was evaluated. Both species of bacteria were able to remove cadmium ions from an aqueous solution and enhanced cadmium mobilization in contaminated soil. Micrococcus sp. and Klebsiella sp. use aminocyclopropane carboxylic acid as a nitrogen source to support their growth, and the minimum inhibitory concentrations of cadmium for Micrococcus sp. and Klebsiella sp. were 1000 and 800mM, respectively. These bacteria promoted root elongation in H. annuus seedlings in both the absence and presence of cadmium compared to uninoculated seedlings. Inoculation with these bacteria was found to increase the root lengths of H. annuus that had been planted in cadmium-contaminated soil. An increase in dry weight was observed for H. annuus inoculated with Micrococcus sp. Moreover, Micrococcus sp. enhanced the accumulation of cadmium in the root and leaf of H. annuus compared to untreated plants. The highest cadmium accumulation in the whole plant was observed when the plants were treated with EDTA following the treatment with Micrococcus sp. In addition, the highest translocation of cadmium from root to the above-ground tissues of H. annuus was found after treatment with Klebsiella sp. in the fourth week after planting. Our results show that plant growth and cadmium accumulation in H. annuus was significantly enhanced by cadmium-resistant PGPRs, and these bacterial inoculants are excellent promoters of phytoextraction for the rehabilitation of heavy metal-polluted environments.

  19. Wild helianthus species used for broadening the genetic base of cultivated sunflower in India

    OpenAIRE

    Sujatha M

    2006-01-01

    The present investigation has been undertaken to introgress desirable traits from wild sunflowers to cultivated sunflower. Using conventional methods of crossing, backcrossing and selection, several pre-bred lines with altered plant architecture, high yield and oil content, maturity duration and inbuilt tolerance to major biotic stresses have been developed from crosses involving diploid annuals. These recombinant interspecific inbred lines are being utilized in the national sunflower network...

  20. Hybrid zone origins, species boundaries, and the evolution of wing-pattern diversity in a polytypic species complex of North American admiral butterflies (Nymphalidae: Limenitis).

    Science.gov (United States)

    Mullen, Sean P; Dopman, Erik B; Harrison, Richard G

    2008-06-01

    Hybrid zones present opportunities to study the effects of gene flow, selection, and recombination in natural populations and, thus, provide insights into the genetic and phenotypic changes that occur early in speciation. Here we investigate a hybrid zone between mimetic (Limenitis arthemis astyanax) and nonmimetic (Limenitis arthemis arthemis) populations of admiral butterflies using DNA sequence variation from mtDNA and seven nuclear gene loci. We find three distinct mitochondrial clades within this complex, and observe a strong overall concordance between wing-pattern phenotypes and mitochondrial variation. Nuclear gene genealogies, in contrast, revealed no evidence of exclusivity for either wing-pattern phenotype, suggesting incomplete barriers to gene exchange and/or insufficient time for lineage sorting. Coalescent simulations indicate that gene flow between these two subspecies is highly asymmetric, with the majority of migration occurring from mimetic into nonmimetic populations. Selective sweeps of alleles responsible for mimetic phenotypes may have occurred more than once when mimetic and nonmimetic Limenitis occurred together in the presence of the model (Battus philenor).

  1. Changes in the Fatty Acid Profile and Phospholipid Molecular Species Composition of Human Erythrocyte Membranes after Hybrid Palm and Extra Virgin Olive Oil Supplementation.

    Science.gov (United States)

    Pacetti, D; Gagliardi, R; Balzano, M; Frega, N G; Ojeda, M L; Borrero, M; Ruiz, A; Lucci, P

    2016-07-13

    This work aims to evaluate and compare, for the first time, the effects of extra virgin olive oil (EVOO) and hybrid palm oil (HPO) supplementation on the fatty acid profile and phospholipid (PL) molecular species composition of human erythrocyte membranes. Results supported the effectiveness of both HPO and EVOO supplementation (3 months, 25 mL/day) in decreasing the lipophilic index of erythrocytes with no significant differences between HPO and EVOO groups at month 3. On the other hand, the novel and rapid ultraperformance liquid chromatography-tandem mass spectrometry method used for PL analysis reveals an increase in the levels of phosphatidylcholine and phosphatidylethanolamine species esterified with polyunsaturated fatty acids. This work demonstrates the ability of both EVOO and HPO to increase the degree of unsaturation of erythrocyte membrane lipids with an improvement in membrane fluidity that could be associated with a lower risk of developing cardiovascular diseases.

  2. Selection of hybrids and edible citrus species with a high content in the diosmin functional compound. Modulating effect of plant growth regulators on contents.

    Science.gov (United States)

    Marín, F R; Del Río, J A

    2001-07-01

    The purpose of this study is to identify species, hybrids, and cultivars of edible Citrus species with high contents of diosmin as a functional compound and also to identify the developmental progress of the fruit in which it reaches maximum levels; these findings would be useful for extraction purposes and for the modulating effect of plant growth regulators on diosmin content to increase the level of this flavone. The results obtained reveal that the highest contents of diosmin are present in immature fruits of certain varieties of citron (Buda's finger) and lemon (Meyer), whereas the contents in the edible parts of the fruits are irrelevant from a pharmacological point of view. Similarly, it is shown that it is possible to increase the content of this flavone using hormonal treatments (6-benzylaminopurine and 2,4-dichlorophenoxyacetic acid) during the early stages of fruit growth.

  3. Occurrence of hybrids and laboratory evidence of fertility among three species of the Phyllosoma complex (Hemiptera: Reduviidae in Mexico

    Directory of Open Access Journals (Sweden)

    José Alejandro Martínez-Ibarra

    2009-12-01

    Full Text Available In seven studied communities of Western Mexico, triatomine specimens were sympatrically collected, some with atypical morphological characteristics in contrast to pure specimens, which were presumed to be hybrids. More than 200 specimens of Meccus pallidipennis and Meccus longipennis with brown-yellow markings on dorsal connexival segments were collected in Ahuacapán and Quitupan. In La Mesa, more than 60 specimens similar to Meccus picturatus in most morphological characteristics (including size were collected, although they presented a largely yellowish corium like M. pallidipennis. Interfertility was proven between all of the studied wild hybrid specimens, as well as between all the experimental laboratory hybrids. Two different phenotypes (M. picturatus and M. longipennis were obtained from crosses between M. picturatus x M. picturatus and M. longipennis x M. longipennis from the three studied localities in state of Nayarit as from La Mesita. Results support the hypothesis that the subspecific ranking of those triatomines may, therefore, be more appropriate because reproductive isolation has not been developed and complete interbreeding was recorded.

  4. Occurrence of hybrids and laboratory evidence of fertility among three species of the Phyllosoma complex (Hemiptera: Reduviidae) in Mexico.

    Science.gov (United States)

    Martínez-Ibarra, José Alejandro; Salazar-Schettino, Paz María; Nogueda-Torres, Benjamín; Vences, Mauro Omar; Tapia-González, José María; Espinoza-Gutiérrez, Bertha

    2009-12-01

    In seven studied communities of Western Mexico, triatomine specimens were sympatrically collected, some with atypical morphological characteristics in contrast to pure specimens, which were presumed to be hybrids. More than 200 specimens of Meccus pallidipennis and Meccus longipennis with brown-yellow markings on dorsal connexival segments were collected in Ahuacapán and Quitupan. In La Mesa, more than 60 specimens similar to Meccus picturatus in most morphological characteristics (including size) were collected, although they presented a largely yellowish corium like M. pallidipennis. Interfertility was proven between all of the studied wild hybrid specimens, as well as between all the experimental laboratory hybrids. Two different phenotypes (M. picturatus and M. longipennis) were obtained from crosses between M. picturatus x M. picturatus and M. longipennis x M. longipennis from the three studied localities in state of Nayarit as from La Mesita. Results support the hypothesis that the subspecific ranking of those triatomines may, therefore, be more appropriate because reproductive isolation has not been developed and complete interbreeding was recorded.

  5. Generation of amphidiploids from hybrids of wheat and related species from the genera Aegilops, Secale, Thinopyrum, and Triticum as a source of genetic variation for wheat improvement.

    Science.gov (United States)

    Nemeth, Csilla; Yang, Cai-yun; Kasprzak, Paul; Hubbart, Stella; Scholefield, Duncan; Mehra, Surbhi; Skipper, Emma; King, Ian; King, Julie

    2015-02-01

    We aim to improve diversity of domesticated wheat by transferring genetic variation for important target traits from related wild and cultivated grass species. The present study describes the development of F1 hybrids between wheat and related species from the genera Aegilops, Secale, Thinopyrum, and Triticum and production of new amphidiploids. Amphidiploid lines were produced from 20 different distant relatives. Both colchicine and caffeine were successfully used to double the chromosome numbers. The genomic constitution of the newly formed amphidiploids derived from seven distant relatives was determined using genomic in situ hybridization (GISH). Altogether, 42 different plants were analysed, 19 using multicolour GISH separating the chromosomes from the A, B, and D genomes of wheat, as well as the distant relative, and 23 using single colour GISH. Restructuring of the allopolyploid genome, both chromosome losses and aneuploidy, was detected in all the genomes contained by the amphidiploids. From the observed chromosome numbers there is an indication that in amphidiploids the B genome of wheat suffers chromosome losses less frequently than the other wheat genomes. Phenotyping to realize the full potential of the wheat-related grass germplasm is underway, linking the analyzed genotypes to agronomically important target traits.

  6. Somatic hybrids of Solanum tuberosum and species of the Solanum nigrum-complex and their backcross progeny

    NARCIS (Netherlands)

    Horsman, K.

    2001-01-01

    The species of the Solanum nigrum-complex are wild relatives of the cultivated potato and potentially interesting sources of genetic variation. The traditional method of introgressing a specific trait from a related species is sexual hybridisation followed by recurrent backcrossing but often one or

  7. Marine Fish Hybridization

    KAUST Repository

    He, Song

    2017-04-01

    Natural hybridization is reproduction (without artificial influence) between two or more species/populations which are distinguishable from each other by heritable characters. Natural hybridizations among marine fishes were highly underappreciated due to limited research effort; it seems that this phenomenon occurs more often than is commonly recognized. As hybridization plays an important role in biodiversity processes in the marine environment, detecting hybridization events and investigating hybridization is important to understand and protect biodiversity. The first chapter sets the framework for this disseration study. The Cohesion Species Concept was selected as the working definition of a species for this study as it can handle marine fish hybridization events. The concept does not require restrictive species boundaries. A general history and background of natural hybridization in marine fishes is reviewed during in chapter as well. Four marine fish hybridization cases were examed and documented in Chapters 2 to 5. In each case study, at least one diagnostic nuclear marker, screened from among ~14 candidate markers, was found to discriminate the putative hybridizing parent species. To further investigate genetic evidence to support the hybrid status for each hybrid offspring in each case, haploweb analysis on diagnostic markers (nuclear and/or mitochondrial) and the DAPC/PCA analysis on microsatellite data were used. By combining the genetic evidences, morphological traits, and ecological observations together, the potential reasons that triggered each hybridization events and the potential genetic/ecology effects could be discussed. In the last chapter, sequences from 82 pairs of hybridizing parents species (for which COI barcoding sequences were available either on GenBank or in our lab) were collected. By comparing the COI fragment p-distance between each hybridizing parent species, some general questions about marine fish hybridization were discussed: Is

  8. Six new Phytophthora species from ITS Clade 7a including two sexually functional heterothallic hybrid species detected in natural ecosystems in Taiwan.

    NARCIS (Netherlands)

    Jung, T.; Jung, M.H.; Scanu, B.; Seress, D.; Kovács, G.M.; Maia, C.; Pérez-Sierra, A.; Chang, T.-T.; Chandelier, A.; Heungens, K.; Poucke, van K.; Abad-Campos, P.; Léon, M.; Cacciola, S.O.; Bakonyi, J.

    2017-01-01

    During a survey of Phytophthora diversity in natural ecosystems in Taiwan six new species were detected. Multigene phylogeny based on the nuclear ITS, ß-tubulin and HSP90 and the mitochondrial cox1 and NADH1 gene sequences demonstrated that they belong to ITS Clade 7a with P. europaea, P. uniformis,

  9. Components of phenotypic variability for head diameter in sunflower - Helianthus annuus L.

    OpenAIRE

    Hladni Nada; Škorić Dragan; Kraljević-Balalić Marija

    2003-01-01

    Sunflower is the main crop species for the production of edible oil in many countries of the world, including ours. Plant height and head size, form and position on the stem as well as the number of leaves, their size, duration and distribution on the plant all play an important role in defining optimal plant architecture in sunflower hybrids (Škorić, 1975, 1989, 2002). In order to monitor the mode of inheritance and gene effects for head diameter in the F1 and F2 generations, half diallel cr...

  10. Genetic analysis of yield and yield related traits in sunflower (Helianthus annuus L. under well-watered and water-stressed conditions

    Directory of Open Access Journals (Sweden)

    Darvishzadeh Reza

    2014-01-01

    Full Text Available Drought stress is one of the factors which influence sunflower (Helianthus annuus L. production. Breeding for tolerance to drought stress has become a major focus. In the present investigation, combining ability, gene action and genetic analysis of several characteristics were studied in six pure lines of sunflower and their 15 hybrids. The materials were evaluated in two separate experiments using a randomized complete block design (RCBD with three replications in two states (well-watered and water-stressed under controlled conditions. Comparison of mean values exhibited that under water- stressed condition the average performance of sunflower genotypes were decreased for all studied traits. In well-watered condition the highest value for seed yield per plant (SY was observed in the cross 'LR4´LR25', whereas in water-stressed condition the highest value for this trait was observed in the hybrid 'C104´LR25'. Combining ability analysis revealed that most of agronomical traits such as head diameter, number of achene per head, head weight and seed yield inherited differently in stressed and non-stressed conditions. In water-stressed conditions, the non-additive effects played a more important role for controlling the number of achene per head (NA, seed yield per plant (SY, head diameter (HD, and days from flowering to physiological maturity (DFM than additive. Based on results yield improvement for water-stressed conditions requires selection under drought conditions. In well-watered condition, the cross 'LR4´C10' showed the best SCA value for seed yield per plant (SY. In water-stressed conditions, 'RHA266´C100' had the highest SCA for seed yield per plant (SY and number of achene (NA per head.

  11. From hybrid swarms to swarms of hybrids

    Science.gov (United States)

    The introgression of modern humans (Homo sapiens) with Neanderthals 40,000 YBP after a half-million years of separation, may have led to the best example of a hybrid swarm on earth. Modern trade and transportation in support of the human hybrids has continued to introduce additional species, genotyp...

  12. Genetic differences between blight-causing Erwinia species with differing host specificities, identified by suppression subtractive hybridization.

    Science.gov (United States)

    Triplett, Lindsay R; Zhao, Youfu; Sundin, George W

    2006-11-01

    PCR-based subtractive hybridization was used to isolate sequences from Erwinia amylovora strain Ea110, which is pathogenic on apples and pears, that were not present in three closely related strains with differing host specificities: E. amylovora MR1, which is pathogenic only on Rubus spp.; Erwinia pyrifoliae Ep1/96, the causal agent of shoot blight of Asian pears; and Erwinia sp. strain Ejp556, the causal agent of bacterial shoot blight of pear in Japan. In total, six subtractive libraries were constructed and analyzed. Recovered sequences included type III secretion components, hypothetical membrane proteins, and ATP-binding proteins. In addition, we identified an Ea110-specific sequence with homology to a type III secretion apparatus component of the insect endosymbiont Sodalis glossinidius, as well as an Ep1/96-specific sequence with homology to the Yersinia pestis effector protein tyrosine phosphatase YopH.

  13. Nuclear and chloroplast microsatellite markers to assess genetic diversity and evolution in hazelnut species, hybrids and cultivars

    Science.gov (United States)

    The U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS), National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon, preserves more than 800 accessions of hazelnut (Corylus) including C. avellana cultivars and representatives of 10 other recognized shrub and tree species...

  14. Quantitation of isobaric phosphatidylcholine species in human plasma using a hybrid quadrupole linear ion trap mass spectrometer

    Science.gov (United States)

    Phosphatidylcholine (PC) species in human plasma are used as biomarkers of disease. PC biomarkers are often limited by the inability to separate isobaric PC. In this work, we developed a targeted shotgun approach for analysis of isobaric and isomeric PC. This approach is comprised of two mass spectr...

  15. Enzymatic browning and after-cooking darkening of Jerusalem artichoke tubers (Helianthus tuberosus L.).

    Science.gov (United States)

    Bach, Vibe; Jensen, Sidsel; Clausen, Morten R; Bertram, Hanne C; Edelenbos, Merete

    2013-11-15

    Jerusalem artichoke tubers (Helianthus tuberosus L.) undergo enzymatic browning when peeled or cut, and turn grey after boiling, due to after-cooking darkening reactions between iron and phenolic acids. In an attempt to reveal the components responsible for these discolouration reactions, sensory evaluation and instrumental colour measurements were related to contents of total phenolics, phenolic acids, organic acids and iron in three varieties of raw and boiled Jerusalem artichoke tubers harvested in the autumn and the spring. No differences were found between varieties in sensory evaluated enzymatic browning, but Rema and Draga had higher scores than Mari in after-cooking darkening. Jerusalem artichoke tubers had higher contents of total phenolics, phenolic acids and citric acid in the autumn and low contents in the spring, while it was the opposite for malic acid. None of the chemical parameters investigated could explain the discolouration of the Jerusalem artichoke tubers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Metabolomics reveals drastic compositional changes during overwintering of Jerusalem artichoke (Helianthus tuberosus L.) tubers.

    Science.gov (United States)

    Clausen, Morten R; Bach, Vibe; Edelenbos, Merete; Bertram, Hanne C

    2012-09-19

    Metabolic changes were investigated in overwintering Jerusalem artichoke (Helianthus tuberosus L.) tubers using proton nuclear magnetic resonance ((1)H NMR) metabolomics. Three varieties were studied; as a result of overwintering, the amount of inulin was found to decrease in Jerusalem artichoke tubers. This was mainly due to its conversion to sucrose and, at the same time, formation of inulin with a lower degree of polymerization. Major effects on the concentration of citric acid, malic acid, γ-aminobutyric acid (GABA), and adenosine were also found. Intriguingly, malic acid concentration increased and citric acid concentration decreased. These changes, together with an increase in sucrose and GABA concentrations, were ascribed to mobilization of nutrients prior to sprouting, suggesting that malic acid and GABA serve as carbon and nitrogen sources during sprouting of Jerusalem artichokes.

  17. Genetic diversity of worldwide Jerusalem artichoke (Helianthus tuberosus) germplasm as revealed by RAPD markers.

    Science.gov (United States)

    Wangsomnuk, P P; Khampa, S; Wangsomnuk, P; Jogloy, S; Mornkham, T; Ruttawat, B; Patanothai, A; Fu, Y B

    2011-12-12

    Jerusalem artichoke (Helianthus tuberosus) is a wild relative of the cultivated sunflower (H. annuus); it is an old tuber crop that has recently received renewed interest. We used RAPD markers to characterize 147 Jerusalem artichoke accessions from nine countries. Thirty RAPD primers were screened; 13 of them detected 357 reproducible RAPD bands, of which 337 were polymorphic. Various diversity analyses revealed several different patterns of RAPD variation. More than 93% of the RAPD variation was found within accessions of a country. Weak genetic differentiation was observed between wild and cultivated accessions. Six groups were detected in this germplasm set. Four ancestral groups were found for the Canadian germplasm. The most genetically distinct accessions were identified. These findings provide useful diversity information for understanding the Jerusalem artichoke gene pool, for conserving Jerusalem artichoke germplasm, and for choosing germplasm for genetic improvement.

  18. Economically Viable Components from Jerusalem Artichoke (Helianthus tuberosus L.) in a Biorefinery Concept

    DEFF Research Database (Denmark)

    Johansson, Eva; Prade, Thomas; Angelidaki, Irini

    2015-01-01

    Biorefinery applications are receiving growing interest due to climatic and waste disposal issues and lack of petroleum resources. Jerusalem artichoke (Helianthus tuberosus L.) is suitable for biorefinery applications due to high biomass production and limited cultivation requirements. This paper...... focuses on the potential of Jerusalem artichoke as a biorefinery crop and the most viable products in such a case. The carbohydrates in the tubers were found to have potential for production of platform chemicals, e.g., succinic acid. However, economic analysis showed that production of platform chemicals...... bioactive activity was found in the young leaves of the crop, and the sesquiterpene lactones are of specific interest, as other compounds from this group have shown inhibitory effects on several human diseases. Thus, future focus should be on understanding the usefulness of small molecules, to develop...

  19. Data on mass spectrometry based identification of allergens from sunflower (Helianthus annuus L. pollen proteome

    Directory of Open Access Journals (Sweden)

    Nandini Ghosh

    2016-06-01

    Full Text Available Allergy is a type of abnormal immune reactions, which is triggered by environmental antigens or allergens and mediated by IgE antibodies. Now-a-days mass spectrometry is the method of choice for allergen identification based on homology searching. Here, we provide the mass spectrometry dataset associated with our previously published research article on identification of sunflower pollen allergens (Ghosh et al., 2015 [1]. In this study allergenicity of sunflower (Helianthus annuus pollen grains were primarily investigated by clinical studies followed by detailed immunobiochemical and immunoproteomic analyses. The mass spectrometry data for the identification of allergens were deposited to ProteomeXchange Consortium via PRIDE partner repository with the dataset identifier http://www.ebi.ac.uk/pride/archive/projects/PXD002397.

  20. Plant growth regulating activity of three polyacetylenes from Helianthus annuus L.

    Science.gov (United States)

    Hong, Si Won; Hasegawa, Koji; Shigemori, Hideyuki

    2009-01-01

    Three polyacetylenes, 8-(beta-D-glucopyranosyloxy)-3-hydroxy-1,9,14-pentadecatriene-4,6-diyne, termed "helian"(1), 8-acetoxy-3-hydroxy-1,9,14-pentadecatriene-4,6-diyne (2), and 3,8-dihydroxy-1,9,14-pentadecatriene-4,6-diyne (3) were isolated from seedlings of sunflower, Helianthus annuus L. cv Russia. Compounds 1 and 2, having a beta-glucose and an acetoxy group at C-8, respectively, showed a weak effect on the growth of roots and shoots of rice (Oryza sativa L.) and cress (Lepidium sativum L.), while compound 3, having a free hydroxyl group at C-8, exhibited a growth promoting effect on the roots and shoots of rice and cress.

  1. Isolation of Bioactive Compounds from Sunflower Leaves (Helianthus annuus L.) Extracted with Supercritical Carbon Dioxide.

    Science.gov (United States)

    El Marsni, Zouhir; Torres, Ascension; Varela, Rosa M; Molinillo, José M G; Casas, Lourdes; Mantell, Casimiro; Martinez de la Ossa, Enrique J; Macias, Francisco A

    2015-07-22

    The work described herein is a continuation of our initial studies on the supercritical fluid extraction (SFE) with CO2 of bioactive substances from Helianthus annuus L. var. Arianna. The selected SFE extract showed high activity in the wheat coleoptile bioassay, in Petri dish phytotoxicity bioassays, and in the hydroponic culture of tomato seeds. Chromatographic fractionations of the extracts and a spectroscopic analysis of the isolated compounds showed 52 substances belonging to 10 different chemical classes, which were mainly sesquiterpene lactones, diterpenes, and flavonoids. Heliannuol M (31), helivypolides K and L (36, 37), and helieudesmanolide B (38) are described for the first time in the literature. Metabolites have been tested in the etiolated wheat coleoptile bioassay with good results in a noteworthy effect on germination. The most active compounds were also tested on tomato seeds, heliannuol A (30) and leptocarpin (45) being the most active, with values similar to those of the commercial herbicide.

  2. Cloning and Functional Analysis of the Bifunctional Agglutinin/Trypsin Inhibitor from Helianthus tuberosus L.

    Institute of Scientific and Technical Information of China (English)

    Tuanjie Chang; Hongli Zhai; Songbiao Chen; Guisheng Song; Honglin Xu; Xiaoli Wei; Zhen Zhu

    2006-01-01

    In order to find new insect resistance genes, four homologous cDNAs, hta-a, hta-b, hta-c and hta-d with lengths of 775, 718, 784 and 752 bp, respectively (GenBank accession numbers AF477031-AF477034), were isolated from a tuber cDNA expression library of Helianthus tuberosus L. Sequence analysis revealed that all four cDNAs contain an open reading frame of 444 bp, coding a polypeptide of 147 amino acid residues, and that the sequences of the cDNAs are very similar to those of the mannose-binding agglutinin genes of the jacalin-related family. In hemagglutination reactions and hapten inhibition assays, affinity-purified HTA (Helianthus tuberosus agglutinin) from induced Escherichia coli BL21(DE3) expressing GST-HTA shows hemagglutination ability and a higher carbohydrate-binding ability for mannose than other tested sugars.Trypsin inhibitory activity was detected in the crude extracts of induced E. coli BL21(DE3)expressing HTA,and was further verified by trypsin inhibitory activity staining on native polyacrylamide gel. The mechanism of interaction between HTA and trypsin was studied by molecular modeling. We found that plenty of hydrogen bonds and electrostatic interactions can be formed between the supposed binding sites of HTA-b and the active site of trypsin, and that a stable HTA/trypsin complex can be formed. The results above imply that HTA might be a bifunctional protein with carbohydrate-binding activity and trypsin inhibitory activity. Moreover,Northern blotting analysis demonstrated that hta is predominantly expressed in tubers of H. tuberosus, very weakly expressed in stems, but not expressed at all in other tissues. Southern blotting analysis indicated that hta is encoded by a multi-gene family. The insect resistance traits have been described in another paper.

  3. Effects of copper on chlorophyll, proline, protein and abscisic acid level of sunflower (Helianthus annuus L.) seedlings.

    Science.gov (United States)

    Zengin, Fikriye Kirbag; Kirbag, Sevda

    2007-07-01

    The effect of copperchloride (CuCl2) on the level of chlorophyll (a+b), proline, protein and abscisic acid in sunflower (Helianthus annuus L.) seedlings were investigated Control and copper treated (0.4, 0.5 and 0.6 mM) seedlings were grown for ten days in Hoagland solution. Abscisic acid content was determined in root, shoot and leaf tissues of seedlings by HPLC. Copper stress caused significant increase of the abscisic acid contents in roots, shoots and leaves of seedlings. The increase was dependent on the copper salt concentration. Enhanced accumulation of proline in the leaves of seedlings exposed to copper was determined, as well as a decrease of chlorophyll (a+b) and total protein (p Helianthus annuus L.) seedlings. Thus, we assumed that copper levels increase above some critical points seedling growth get negative effects. This assumption is in line with previous findings.

  4. THE EFFECT OF SPRUCE BARK POLYPHENOLS EXTRACT IN COMBINATION WITH DEUTERIUM DEPLETED WATER (DDW ON GLYCINE MAX L. AND HELIANTHUS ANNUUS L. DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Corneliu Tanase

    2010-09-01

    Full Text Available The aim of this study was to evaluate the effect of spruce bark aqueous extract and deuterium depleted water (DDW as bioregulators on the plant growth Glycine max L. and Helianthus annuus. The following specific parameteres were closely monitorised: germination energy and germination capacity, plants vegetative organelles growth and development and photoassimilatory pigments concentrations. The results have shown that DDW presents different effects depending on tested plant species. In the case of soybean, DDW presented stimulatory effects on both germination energy and capacity, radicles elongation, primary leaves growth and development but inhibitory effects on photoassimilatory pigments. Spruce bark extract reduced the germination capacity of soybean seeds, but accelerated the germination process of sunflower seeds and present stimulatory effects on plantlets biomass accumulation. The combination of DDW with Picea abies polyphenolic extract promoted soybean plantlet elongation, especially the rootlets ones and stimulated green biomass accumulation for both soybean and sunflower plantlets. Analyzing the photoassimilatory pigments concentration for sunflower, it can be observed an increasing trend (almost 100% comparing with control when introduce into the growth medium DDW and P. abies polyphenolic extract. DDW and P. abies bark extract have shown an important role in plant growth and development, improving photoassimiliation process.

  5. Evaluation of a hybrid sampling train for measuring trace elements and identifying mercury species in combustion flue gas

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S.F.; Wincek, R.T.; Miller, B.G.; Scaroni, A.W.

    1999-07-01

    The Environmental Protection Agency (EPA) initiated an information collection request (ICR) on January 1, 1999 for coal-fired electric utility steam generating units (>25 MW) to document mercury levels in their fuels and emissions. The issuance of an ICR generally precedes the implementation of regulatory action by the EPA. The EPA has designated the Modified Ontario Hydro Method for stack gas sampling to measure total, elemental and oxidized mercury. This recommendation is based on extensive work by the University of North Dakota Energy and Environmental Research Center (UNDEERC) in evaluating a series of methodologies for determining mercury speciation. EPA has also designed the Method 29 sampling train for the sampling and measurement of the other elements identified as HAP's, i.e. As, Be, Cd, Co, Mn, Ni, Pb, Sb, Se, and Hg. Extensive testing has shown that EPA Method 29 may not speciate mercury correctly; however, it may still be used to measure total mercury. Currently there are no emission restrictions on these elements from power plants, however studies are being conducted as to their health risk and environmental impact. The objective of the study is to evaluate a hybrid train consisting of components of both the Modified Ontario Hydro Method and Method 29 sampling trains. Both sampling procedures are very labor intensive and require time to develop sampling expertise. The various sample trains are being tested in a 20 million Btu/hr demonstration boiler and a 2 million Btu/hr research boiler using a variety of fuels and combustion conditions.

  6. Characterizing the Status (Disturbed, Hybrid or Novel) of Swamp Forest Fragments in a Caribbean Ramsar Wetland: The Impact of Anthropogenic Degradation and Invasive Plant Species

    Science.gov (United States)

    Prospere, Kurt; McLaren, Kurt P.; Wilson, Byron

    2016-10-01

    The last remaining Amazonian-type swamp forest fragments in Black River Lower Morass, Jamaica, have been subjected to a myriad of anthropogenic disturbances, compounded by the establishment and spread of several invasive plant species. We established 44 permanent sample plots (covering 3.92 ha) across 10 of these swamp forest fragments and sampled all non-woody plants and all trees ≥2 cm DBH found in the plots. These data were used to (1) identify thresholds of hybridity and novelty, (2) derive several diversity and structural descriptors used to characterize the swamp forest fragments and (3) identify possible indicators of anthropogenic degradation. These were incorporated into a framework and used to determine the status of the swamp forest fragments so that appropriate management and conservation measures can be implemented. We recorded 43 woody plant species (9 endemic, 28 native and 4 non-native) and 21 non-tree species. The composition and structure of all the patches differed significantly due to the impact of the herbaceous invasive plant Alpinia allughas, the presence and diversity of other non-native plants, and differing intensities of anthropogenic disturbance (e.g., burning, cutting and harvesting of non-timber forest products). We ranked forest patches along a continuum representing deviations from a historical proxy (least disturbed) swamp forest to those with dramatically altered structural and floristic attributes (=novel swamp forests). Only one fragment overrun with A. allughas was classified as novel. If effective conservation and management does not come to the BRLM, the remaining swamp forest fragments appear doomed to further degradation and will soon disappear altogether.

  7. Characterizing the Status (Disturbed, Hybrid or Novel) of Swamp Forest Fragments in a Caribbean Ramsar Wetland: The Impact of Anthropogenic Degradation and Invasive Plant Species.

    Science.gov (United States)

    Prospere, Kurt; McLaren, Kurt P; Wilson, Byron

    2016-10-01

    The last remaining Amazonian-type swamp forest fragments in Black River Lower Morass, Jamaica, have been subjected to a myriad of anthropogenic disturbances, compounded by the establishment and spread of several invasive plant species. We established 44 permanent sample plots (covering 3.92 ha) across 10 of these swamp forest fragments and sampled all non-woody plants and all trees ≥2 cm DBH found in the plots. These data were used to (1) identify thresholds of hybridity and novelty, (2) derive several diversity and structural descriptors used to characterize the swamp forest fragments and (3) identify possible indicators of anthropogenic degradation. These were incorporated into a framework and used to determine the status of the swamp forest fragments so that appropriate management and conservation measures can be implemented. We recorded 43 woody plant species (9 endemic, 28 native and 4 non-native) and 21 non-tree species. The composition and structure of all the patches differed significantly due to the impact of the herbaceous invasive plant Alpinia allughas, the presence and diversity of other non-native plants, and differing intensities of anthropogenic disturbance (e.g., burning, cutting and harvesting of non-timber forest products). We ranked forest patches along a continuum representing deviations from a historical proxy (least disturbed) swamp forest to those with dramatically altered structural and floristic attributes (=novel swamp forests). Only one fragment overrun with A. allughas was classified as novel. If effective conservation and management does not come to the BRLM, the remaining swamp forest fragments appear doomed to further degradation and will soon disappear altogether.

  8. Genetics and mapping of the R₁₁ gene conferring resistance to recently emerged rust races, tightly linked to male fertility restoration, in sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Qi, L L; Seiler, G J; Vick, B A; Gulya, T J

    2012-09-01

    Sunflower oil is one of the major sources of edible oil. As the second largest hybrid crop in the world, hybrid sunflowers are developed by using the PET1 cytoplasmic male sterility system that contributes to a 20 % yield advantage over the open-pollinated varieties. However, sunflower production in North America has recently been threatened by the evolution of new virulent pathotypes of sunflower rust caused by the fungus Puccinia helianthi Schwein. Rf ANN-1742, an 'HA 89' backcross restorer line derived from wild annual sunflower (Helianthus annuus L.), was identified as resistant to the newly emerged rust races. The aim of this study was to elucidate the inheritance of rust resistance and male fertility restoration and identify the chromosome location of the underlying genes in Rf ANN-1742. Chi-squared analysis of the segregation of rust response and male fertility in F(2) and F(3) populations revealed that both traits are controlled by single dominant genes, and that the rust resistance gene is closely linked to the restorer gene in the coupling phase. The two genes were designated as R ( 11 ) and Rf5, respectively. A set of 723 mapped SSR markers of sunflower was used to screen the polymorphism between HA 89 and the resistant plant. Bulked segregant analysis subsequently located R ( 11 ) on linkage group (LG) 13 of sunflower. Based on the SSR analyses of 192 F(2) individuals, R ( 11 ) and Rf5 both mapped to the lower end of LG13 at a genetic distance of 1.6 cM, and shared a common marker, ORS728, which was mapped 1.3 cM proximal to Rf5 and 0.3 cM distal to R ( 11 ) (Rf5/ORS728/R ( 11 )). Two additional SSRs were linked to Rf5 and R ( 11 ): ORS995 was 4.5 cM distal to Rf5 and ORS45 was 1.0 cM proximal to R ( 11 ). The advantage of such an introduced alien segment harboring two genes is its large phenotypic effect and simple inheritance, thereby facilitating their rapid deployment in sunflower breeding programs. Suppressed recombination was observed in LGs 2, 9

  9. Identification of a male meiosis-specific gene, Tcte2, which is differentially spliced in species that form sterile hybrids with laboratory mice and deleted in t chromosomes showing meiotic drive.

    Science.gov (United States)

    Braidotti, G; Barlow, D P

    1997-06-01

    Tcte2 (t complex testes expressed 2) is a male meiosis-specific gene that maps to band 3.3 of mouse chromosome 17. Two distinct male fertility defects, hybrid sterility and transmission ratio distortion, have previously been mapped to this region. Hybrid sterility arises in crosses between different mouse species and the F1 generation males have defects in the first meiotic division and are sterile. Transmission ratio distortion is shown by males heterozygous for the t haplotype form of chromosome 17 and is a type of meiotic drive in which male gametes function unequally at fertilization. The Tcte2 gene expresses a coding mRNA and a number of putative non-ORF transcripts in meiosis I. A deletion of the 5' part of the locus abolishes Tcte2 expression on the t haplotype form of chromosome 17. Additionally, the series of putative non-ORF RNAs at the Tcte2 locus are differentially spliced in species that show hybrid sterility when crossed to laboratory mice. The identification of polymorphisms in t haplotypes and in different mouse species allows alleles of Tcte2 to be proposed as candidates for loci which contribute to both meiotic drive and hybrid sterility phenotypes. While theoretical considerations have previously been used to propose that speciation and meiotic drive involve alleles of the same genes, Tcte2 is the first cloned candidate gene to support this link at a molecular level.

  10. Stichodactyla helianthus peptide, a pharmacological tool for studying Kv3.2 channels.

    Science.gov (United States)

    Yan, Lizhen; Herrington, James; Goldberg, Ethan; Dulski, Paula M; Bugianesi, Randal M; Slaughter, Robert S; Banerjee, Priya; Brochu, Richard M; Priest, Birgit T; Kaczorowski, Gregory J; Rudy, Bernardo; Garcia, Maria L

    2005-05-01

    Voltage-gated potassium (Kv) channels regulate many physiological functions and represent important therapeutic targets in the treatment of several clinical disorders. Although some of these channels have been well-characterized, the study of others, such as Kv3 channels, has been hindered because of limited pharmacological tools. The current study was initiated to identify potent blockers of the Kv3.2 channel. Chinese hamster ovary (CHO)-K1 cells stably expressing human Kv3.2b (CHO-K1.hKv3.2b) were established and characterized. Stichodactyla helianthus peptide (ShK), isolated from S. helianthus venom and a known high-affinity blocker of Kv1.1 and Kv1.3 channels, was found to potently inhibit 86Rb+ efflux from CHO-K1.hKv3.2b (IC50 approximately 0.6 nM). In electrophysiological recordings of Kv3.2b channels expressed in Xenopus laevis oocytes or in planar patch-clamp studies, ShK inhibited hKv3.2b channels with IC50 values of approximately 0.3 and 6 nM, respectively. Despite the presence of Kv3.2 protein in human pancreatic beta cells, ShK has no effect on the Kv current of these cells, suggesting that it is unlikely that homotetrameric Kv3.2 channels contribute significantly to the delayed rectifier current of insulin-secreting cells. In mouse cortical GABAergic fast-spiking interneurons, however, application of ShK produced effects consistent with the blockade of Kv3 channels (i.e., an increase in action potential half-width, a decrease in the amplitude of the action potential after hyperpolarization, and a decrease in maximal firing frequency in response to depolarizing current injections). Taken together, these results indicate that ShK is a potent inhibitor of Kv3.2 channels and may serve as a useful pharmacological probe for studying these channels in native preparations.

  11. Activation of biologically relevant levels of reactive oxygen species by Au/g-C3N4 hybrid nanozyme for bacteria killing and wound disinfection.

    Science.gov (United States)

    Wang, Zhenzhen; Dong, Kai; Liu, Zhen; Zhang, Yan; Chen, Zhaowei; Sun, Hanjun; Ren, Jinsong; Qu, Xiaogang

    2017-01-01

    As common reactive oxygen species, H2O2 is widely used for bacterial inactivation and wound disinfection. However, the concentrations used are always higher than physiological levels, which frequently result in potential toxicity to healthy tissue and even delay wound healing. Here we report highly efficient nanozyme hybrids that are capable of activating biologically relevant concentrations of H2O2 for defending bacterial infections. The integration of AuNPs with ultrathin graphitic carbon nitride (g-C3N4) provides excellent peroxidase-activity, which can catalyze the decomposition of H2O2 to OH radicals much more efficiently, allowing the use of bio-safety levels of H2O2 for the first time. Furthermore, our system not only exhibits striking bactericidal performance against both DR Gram-negative and DR Gram-positive bacteria, but also shows high efficiency in breaking down the existing DR-biofilms and prevented formation of new biofilms in vitro. More importantly, in vivo experiments indicate that our system could significantly prevent bacterial infections and accelerate the healing rate of wounds.

  12. Design of species-specific oligonucleotide probes for the detection of Bacteroides and Parabacteroides by fluorescence in situ hybridization and their application to the analysis of mouse caecal Bacteroides-Parabacteroides microbiota.

    Science.gov (United States)

    Momose, Y; Park, S H; Miyamoto, Y; Itoh, K

    2011-07-01

    To develop species-specific monitoring techniques for rapid detection of Bacteroides and Parabacteroides inhabiting the mouse intestine by fluorescence in situ hybridization. The specificity of oligonucleotide probes was evaluated by fluorescence whole-cell hybridization. Oligonucleotide probes specific for each species hybridized only with the target bacteria. Using these probes, caecal Bacteroides-Parabacteroides microbiota of conventional mice and specific pathogen-free (SPF) mice from three different breeders were analysed. It was shown that Bacteroides acidifaciens Group-1, Group-2 and Group-3 were dominant in conventional mice and SPF mice from two out of three breeders. Bacteroides vulgatus and Parabacteroides distasonis were detected in one of these two SPF breeding colonies in addition to Bact. acidifaciens. SPF mice of the remaining breeder harboured characteristic Bacteroides-Parabacteroides microbiota, consisting of Bacteroides sp. ASF519 and Bacteroides caccae. Bacteroides acidifaciens is the dominant and most typical species in the mouse Bacteroides-Parabacteroides microbiota. The Group-3 was identified as a novel group and revealed to occupy a major niche together with Bact. acidifaciens Group-1 and Group-2. The species-specific probe set developed in this study was the efficient tool for rapid detection of target bacterial groups inhabiting the mouse intestine. The results of this study provide important new information on the mouse Bacteroides-Parabacteroides community. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  13. [Evaluation of peptide nucleic acid fluorescent in situ hybridization (PNA FISH) method in the identifi cation of Candida species isolated from blood cultures].

    Science.gov (United States)

    Aydemir, Gonca; Koç, Ayşe Nedret; Atalay, Mustafa Altay

    2016-04-01

    In recent years, increased number of patients who are hospitalized in intensive care units, received immunosuppressive therapy and treated with broad-spectrum antibiotics that can lead an increase in the incidence of systemic candidiasis. In these patients, the most common clinical manifestation is candidemia. Since the identification of Candida species isolated from blood cultures is time consuming by conventional (morphological and biochemical) methods, rapid, reliable and accurate methods are needed. For this purpose novel systems have been developed to identify the agent directly. The aim of this study was to evaluate the peptide nucleic acid fluorescent in situ hybridization (PNA FISH) method for the identification of Candida species by comparing with the conventional methods. A total of 50 patients who were admitted to Erciyes University Medical Faculty Hospital clinics and followed with prediagnosis of systemic fungal infections whose blood cultures were positive for the yeasts between July 2011 and July 2012 were included in the study. The conventional identification of Candida isolates was performed by considering macroscopic and microscopic morphology, germ tube test, cycloheximide sensitivity, urease activity and carbohydrate assimilation patterns with API 20C AUX (bioMerieux, France) test. PNA FISH method was conducted by the use of a commercial kit namely Yeast Traffic Light(®) PNA FISH (AdvanDx, USA). According to morphological and biochemical characteristics (conventional methods), 19 (38%) out of 50 Candida isolates were identified as C.albicans, 12 (24%) as C.glabrata, five (10%) as C.parapsilosis, five (10%) as C.kefyr, four (8%) as C.krusei, two (4%) as C.guilliermondii, two (4%) as C.tropicalis and one (2%) as C.lusitaniae. On the other hand, 24 (48%) of the isolates were identified as C.albicans/C.parapsilosis (with green fluorescence), 16 (32%) as C.glabrata/C.krusei (with red fluorescence) and one (%2) as C.tropicalis (with yellow

  14. Modulation of inflammatory responses by diterpene acids from Helianthus annuus L.

    Science.gov (United States)

    Díaz-Viciedo, Rodrigo; Hortelano, Sonsoles; Girón, Natalia; Massó, Jose M; Rodriguez, Benjamín; Villar, Angel; de Las Heras, Beatriz

    2008-05-02

    Fractionation of a petroleum ether extract of Helianthus annuus L. led to the isolation of three diterpene acids: grandiflorolic, kaurenoic and trachylobanoic acids. These compounds were studied for potential anti-inflammatory activity on the generation of inflammatory mediators in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. At non-toxic concentrations, these compounds reduced, in a concentration-dependent manner nitric oxide (NO), prostaglandin E(2) (PGE(2)) and tumor necrosis factor (TNF-alpha) production, as well as expression of inducible nitric oxide synthase (NOS-2) and cyclooxygenase-2 (COX-2). All diterpenoids displayed significant in vivo anti-inflammatory activity and suppressed the 12-O-tetradecanoylphorbol-13-acetate (TPA)-mouse ear edema. In addition, inhibition of myeloperoxidase (MPO) activity, an index of cellular infiltration, was observed. In summary, our results suggest that the inhibition of the expression of NOS-2, COX-2 and the release of inflammatory cytokines, is responsible for the anti-inflammatory effects of the diterpenoids isolated from H. annuus L. which likely contributes to the pharmacological action of sunflower.

  15. Economically Viable Components from Jerusalem Artichoke (Helianthus tuberosus L. in a Biorefinery Concept

    Directory of Open Access Journals (Sweden)

    Eva Johansson

    2015-04-01

    Full Text Available Biorefinery applications are receiving growing interest due to climatic and waste disposal issues and lack of petroleum resources. Jerusalem artichoke (Helianthus tuberosus L. is suitable for biorefinery applications due to high biomass production and limited cultivation requirements. This paper focuses on the potential of Jerusalem artichoke as a biorefinery crop and the most viable products in such a case. The carbohydrates in the tubers were found to have potential for production of platform chemicals, e.g., succinic acid. However, economic analysis showed that production of platform chemicals as a single product was too expensive to be competitive with petrochemically produced sugars. Therefore, production of several products from the same crop is a must. Additional products are protein based ones from tubers and leaves and biogas from residues, although both are of low value and amount. High bioactive activity was found in the young leaves of the crop, and the sesquiterpene lactones are of specific interest, as other compounds from this group have shown inhibitory effects on several human diseases. Thus, future focus should be on understanding the usefulness of small molecules, to develop methods for their extraction and purification and to further develop sustainable and viable methods for the production of platform chemicals.

  16. Patterns of microsatellite evolution inferred from the Helianthus annuus (Asteraceae) transcriptome

    Indian Academy of Sciences (India)

    Sreepriya Pramod; Andy D. Perkins; Mark E. Welch

    2014-08-01

    The distribution of microsatellites in exons, and their association with gene ontology (GO) terms is explored to elucidate patterns of microsatellite evolution in the common sunflower, Helianthus annuus. The relative position, motif, size and level of impurity were estimated for each microsatellite in the unigene database available from the Compositae Genome Project (CGP), and statistical analyses were performed to determine if differences in microsatellite distributions and enrichment within certain GO terms were significant. There are more translated than untranslated microsatellites, implying that many bring about structural changes in proteins. However, the greatest density is observed within the UTRs, particularly 5′UTRs. Further, UTR microsatellites are purer and longer than coding region microsatellites. This suggests that UTR microsatellites are either younger and under more relaxed constraints, or that purifying selection limits impurities, and directional selection favours their expansion. GOs associated with response to various environmental stimuli including water deprivation and salt stress were significantly enriched with microsatellites. This may suggest that these GOs are more labile in plant genomes, or that selection has favoured the maintenance of microsatellites in these genes over others. This study shows that the distribution of transcribed microsatellites in H. annuus is nonrandom, the coding region microsatellites are under greater constraint compared to the UTR microsatellites, and that these sequences are enriched within genes that regulate plant responses to environmental stress and stimuli.

  17. Patterns of microsatellite evolution inferred from the Helianthus annuus (Asteraceae) transcriptome.

    Science.gov (United States)

    Pramod, Sreepriya; Perkins, Andy D; Welch, Mark E

    2014-08-01

    The distribution of microsatellites in exons, and their association with gene ontology (GO) terms is explored to elucidate patterns of microsatellite evolution in the common sunflower, Helianthus annuus. The relative position, motif, size and level of impurity were estimated for each microsatellite in the unigene database available from the Compositae Genome Project (CGP), and statistical analyses were performed to determine if differences in microsatellite distributions and enrichment within certain GO terms were significant. There are more translated than untranslated microsatellites, implying that many bring about structural changes in proteins. However, the greatest density is observed within the UTRs, particularly 5'UTRs. Further, UTR microsatellites are purer and longer than coding region microsatellites. This suggests that UTR microsatellites are either younger and under more relaxed constraints, or that purifying selection limits impurities, and directional selection favours their expansion. GOs associated with response to various environmental stimuli including water deprivation and salt stress were significantly enriched with microsatellites. This may suggest that these GOs are more labile in plant genomes, or that selection has favoured the maintenance of microsatellites in these genes over others. This study shows that the distribution of transcribed microsatellites in H. annuus is nonrandom, the coding region microsatellites are under greater constraint compared to the UTR microsatellites, and that these sequences are enriched within genes that regulate plant responses to environmental stress and stimuli.

  18. Acyl-acyl carrier protein thioesterase activity from sunflower (Helianthus annuus L.) seeds.

    Science.gov (United States)

    Martínez-Force, E; Cantisán, S; Serrano-Vega, M J; Garcés, R

    2000-10-01

    During sunflower (Helianthus annuus L.) seed formation there was an active period of lipid biosynthesis between 12 and 28 days after flowering (DAF). The maximum in-vitro acyl-acyl carrier protein (ACP) thioesterase activities (EC 3.1.2.14) were found at 15 DAF, preceding the largest accumulation of lipid in the seed. Data from the apparent kinetic parameters, Vmax and Km, from seeds of 15 and 30 DAF, showed that changes in acyl-ACP thioesterase activity are not only quantitative, but also qualitative, since, although the preferred substrate was always oleoyl-ACP, the affinity for palmitoyl-ACP decreased, whereas that for stearoyl-ACP increased with seed maturation. Bisubstrate assays carried out at 30 DAF seemed to indicate that the total activity found in mature seeds is due to a single enzyme with 100/75/15 affinity for oleoyl-ACP/stearoyl-ACP/ palmitoyl-ACP. In contrast, at 15 DAF, enzymatic data together with partial sequences from cDNAs indicated the presence of at least two enzymes with different properties, a FatA-like thioesterase, with a high affinity for oleoyl-ACP, plus a FatB-like enzyme, with preference for long-chain saturated fatty acids, both being expressed during the active lipid biosynthesis period. Competition assays carried out with CAS-5, a mutant with a higher content of palmitic acid in the seed oil, indicated that a modified FatA-type thioesterase is involved in the mutant phenotype.

  19. Sunflower (Helianthus annuus L.) as a pre-Columbian domesticate in Mexico.

    Science.gov (United States)

    Lentz, David L; Pohl, Mary DeLand; Alvarado, José Luis; Tarighat, Somayeh; Bye, Robert

    2008-04-29

    Mexico has long been recognized as one of the world's cradles of domestication with evidence for squash (Cucurbita pepo) cultivation appearing as early as 8,000 cal B.C. followed by many other plants, such as maize (Zea mays), peppers (Capsicum annuum), common beans (Phaseolus vulgaris), and cotton (Gossypium hirsutum). We present archaeological, linguistic, ethnographic, and ethnohistoric data demonstrating that sunflower (Helianthus annuus) had entered the repertoire of Mexican domesticates by ca. 2600 cal B.C., that its cultivation was widespread in Mexico and extended as far south as El Salvador by the first millennium B.C., that it was well known to the Aztecs, and that it is still in use by traditional Mesoamerican cultures today. The sunflower's association with indigenous solar religion and warfare in Mexico may have led to its suppression after the Spanish Conquest. The discovery of ancient sunflower in Mexico refines our knowledge of domesticated Mesoamerican plants and adds complexity to our understanding of cultural evolution.

  20. Initial transitions, order and disorder in phyllotactic patterns: the ontogeny of Helianthus annuus: a case study

    Directory of Open Access Journals (Sweden)

    Yves Couder

    2014-01-01

    Full Text Available The variability of the phyllotactic organization of Helianthus annuus L. is investigated. Specimens exhibiting the various possible phyllotactic modes (Fibonacci spirals, Lucas spirals, bijugate spirals etc... were selected. The transitions from the initial decussate growth to these organizations, were characterized and shown to correspond to only a few archetypes. The possible transients from a decussate mode were then investigated in the model of self organization introduced by Douady and Couder (1996a, b, c. They are shown to exhibit the same phenomenology as the observed ones. These various transients have a very different probability of ccurrence which explains the difference of their frequency in plants. Finally the imperfections of the observed dispositions, which affect mainly the plastochron, are also investigated. The model provides an interpretation of this apparent disorder: after a transition the system optimizes the regularity of the parastichies but in doing so it disturbs the plastochron and the divergence. It is only when very large external disturbances affect the system that a real disorder is generated. In these latter cases the parastichies themselves disappear.

  1. Economically viable components from Jerusalem artichoke (Helianthus tuberosus L.) in a biorefinery concept.

    Science.gov (United States)

    Johansson, Eva; Prade, Thomas; Angelidaki, Irini; Svensson, Sven-Erik; Newson, William R; Gunnarsson, Ingólfur Bragi; Hovmalm, Helena Persson

    2015-04-22

    Biorefinery applications are receiving growing interest due to climatic and waste disposal issues and lack of petroleum resources. Jerusalem artichoke (Helianthus tuberosus L.) is suitable for biorefinery applications due to high biomass production and limited cultivation requirements. This paper focuses on the potential of Jerusalem artichoke as a biorefinery crop and the most viable products in such a case. The carbohydrates in the tubers were found to have potential for production of platform chemicals, e.g., succinic acid. However, economic analysis showed that production of platform chemicals as a single product was too expensive to be competitive with petrochemically produced sugars. Therefore, production of several products from the same crop is a must. Additional products are protein based ones from tubers and leaves and biogas from residues, although both are of low value and amount. High bioactive activity was found in the young leaves of the crop, and the sesquiterpene lactones are of specific interest, as other compounds from this group have shown inhibitory effects on several human diseases. Thus, future focus should be on understanding the usefulness of small molecules, to develop methods for their extraction and purification and to further develop sustainable and viable methods for the production of platform chemicals.

  2. Ultrasound assisted pectic polysaccharide extraction and its characterization from waste heads of Helianthus annus.

    Science.gov (United States)

    Ponmurugan, K; Al-Dhabi, Naif Abdullah; Maran, J Prakash; Karthikeyan, K; Moothy, I Ganesh; Sivarajasekar, N; Manoj, J Jony Blessing

    2017-10-01

    The main aim of this current work is to extract pectin from waste heads of Helianthus annus by ultrasound and optimize the process variables (ultrasound power (USP), pH, time of sonication (TS) and ratio of solid to liquid (RSL) on maximal recovery of pectin using central composite statistical experimental design. In addition to that, extracted pectin at optimal condition was characterized and compared with commercial pectin. The optimal extraction process condition was USP of 375w, pH of 3.2, TS of 32min and RSL of 1:15g/ml. Mean experimental pectin yield of 8.89±0.024% was well accord with predicted pectin yield (8.91%). Analysis of chemical composition and Fourier transform infrared spectroscopy of extracted pectin did not show any significant difference with commercial pectin. XRD analysis illustrated a similar crystalline profile in both extracted and commercial pectin. Morphological analysis was performed on fresh and extracted samples using scanning electron microscopy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Visitantes florales diurnos del girasol (Helianthus annuus, Asterales: Asteraceae en la Argentina

    Directory of Open Access Journals (Sweden)

    Juan P. TORRETTA

    2010-01-01

    Full Text Available El girasol ( Helianthus annuus L. es un importante cultivo oleaginoso en la Argentina. Durante tres campañas agrícolas, se determinaron la diversidad y la abundancia del elenco de los visitantes florales diurnos de capítulos de girasol, en ocho sitios que cubren gran parte del área cultivada en Argentina. Setenta y seis morfo-especies de visitantes florales, pertenecientes a ocho órdenes, fueron capturados sobre capítulos de este cultivo. El principal orden fue Hymenoptera, con 37 especies o morfo- especies, de las cuales 32 fueron abejas (Apoidea. Las familias de abejas más representadas fueron Apidae (13, Megachilidae (11 y Halictidae (7. La abeja doméstica ( Apis mellifera L. realizó el 93% de las visitas. La composición del elenco de visitantes no mostró un patrón de variación identificable a lo largo del día, ni con respecto a la distancia al borde del cultivo, pero varió entre sitios de muestreo. Se concluye que la abeja doméstica es el principal polinizador del girasol en la Argentina, aunque varias especies nativas de abejas ( Melissodes tintinnans (Holmberg, M. rufithorax Brèthes, Melissoptila tandilensis Holmberg, y Megachile spp. podrían ser consideradas como potenciales polinizadores del cultivo.

  4. A Kinetic Study of Marginal Soil Energy Plant Helianthus annuus Stalk Pyrolysis

    Directory of Open Access Journals (Sweden)

    Huaxiao Yan

    2013-01-01

    Full Text Available The pyrolytic characteristics and kinetics of new marginal soil energy plant Helianthus annuus stalk were investigated using thermogravimetric (TG method from 50 to 800°C in an inert argon atmosphere at different heating rates of 5, 10, 20, and 30°C min−1. The kinetic parameters of activation energy and pre-exponential factor were deduced by Popescu, Flynn-Wall-Ozawa (FWO, and Kissinger-Akahira-Sunose (KAS methods, respectively. The results showed that three stages appeared in the thermal degradation process. The primary devolatilization stage of H. annuus stalk can be described by the Avrami-Erofeev function (n=4. The average activation energy of H. annuus stalk was only 142.9 kJ mol−1. There were minor kinetic compensation effects between the pre-exponential factor and the activation energy. The results suggest that H. annuus stalk is suitable for pyrolysis, and more importantly, the experimental results and kinetic parameters provided useful information for the design of pyrolytic processing system using H. annuus stalk as feedstock.

  5. Cadmium Accumulation and Translocation in Two Jerusalem Artichoke (Helianthus tuberosus L.) Cultivars

    Institute of Scientific and Technical Information of China (English)

    CHEN Liang; LONG Xiao-Hua; ZHANG Zhen-Hua; ZHENG Xiao-Tao; Z. RENGEL; LIU Zhao-Pu

    2011-01-01

    Jerusalem artichoke (Helianthus tuberosus L.) not just can be used for bioethanol production but may be potentially used in phytoremediation for the removal of heavy metal pollutants.Two Jerusalem artichoke cultivars,N2 and N5,were subjected to six cadmium (Cd) concentrations (0,5,25,50,100 and 200 mg L-1) to investigate Cd tolerance and accumulation.After 21 days of growth,the effects of Cd on growth,chlorophyll content,net photosynthetic rate,intercellular CO2 concentration and malondialdehyde content were evaluated.Most growth parameters were reduced under Cd stress.The two Jerusalem artichoke cultivars had relatively high Cd tolerance and accumulation capacity (> 100 mg kg-1),with N5 being more tolerant and having higher Cd accumulation than N2.Roots accumulated more Cd than stems and leaves.The bioconcentration factors (far higher than 1) and translocation factors (lower than 1) decreased with an increase in Cd applied.The results suggested that Jerusalem artichoke could be grown at relatively high Cd loads,and N5 could be an excellent candidate for phytoremediation of Cd-contaminated soils.

  6. EFECTO DE EXTRACTOS ACUOSOS DE Helianthus annuus Lin. SOBRE EL CRECIMIENTO DE Solanum lycopersicum Lin.

    Directory of Open Access Journals (Sweden)

    Yaniuska González Perigó

    2015-01-01

    Full Text Available Con el objetivo de determinar el efecto de extractos acuosos de Helianthus annuus Lin. sobre el crecimiento de Solanum lycopersicum Lin, se tomaron muestras de raíz y hojas de plantas recolectadas de un sistema de policultivo ubicado en un agroecosistema montañoso. Los extractos acuosos de girasol se obtuvieron a partir de raíz y hojas de plantas recolectadas durante dos años. Se evaluaron los efectos de estos extractos sobre la germinación, longitud de la radícula y del hipocótilo de semillas de tomate certificadas, para ello se ejecutaron nueve tratamientos con cuatro repeticiones dispuestos en placas Petri. Los extractos de raíz de girasol a los 15, 30 y 45 días y de hojas a los 75 y 90 días de desarrollo inhibieron la germinación de las semillas de tomate y el crecimiento de la radícula y el hipocótilo. Los extractos de raíz de girasol con 75 y 90 días, estimularon el crecimiento de la radícula y del hipocótilo del tomate. Estos resultados demuestran que el girasol produce sustancias químicas que inhiben el crecimiento del tomate y no se recomienda asociar estos dos cultivos de forma simultánea.

  7. Pharmacological effects of two cytolysins isolated from the sea anemone Stichodactyla helianthus

    Indian Academy of Sciences (India)

    T García; D Martinez; A Palmero; C Soto; M Tejuca; F Pazos; R Menéndez; C Alvarez; A Garateix

    2009-12-01

    Sticholysins I and II (St I/II) are cytolysins purified from the sea anemone Stichodactyla helianthus. In this study, we show their pharmacological action on guinea-pig and snail models in native and pH-denatured conditions in order to correlate the pharmacological findings with the pore-forming activity of both isoforms. In guinea-pig erythrocytes ( = 3), St II possessed higher haemolytic activity in comparison with St I and this activity was lost at an alkaline pH. In molluscan central neurons ( = 30), they irreversibly decreased the amplitude of the cholinergic response; St I (EC50 0.6 molL–1) was more potent than St II (EC50 > 6.6 molL–1) and they both increased the duration of the action potential; these effects were absent at an alkaline pH. In guinea-pig isolated atrium ( = 25), both increased the amplitude of the contraction force, but St II was more potent than St I (EC50 0.03 molL–1 and 0.3 molL–1, respectively) and this effect persisted at an alkaline pH. In summary, both cytolysins have neuroactive and cardioactive properties. The main mechanism in molluscan neurons seems to be associated with the cytolytic activity of these molecules, whereas in guinea-pig atrium, the existence of an additional pharmacological mechanism might be contributing to the observed effect.

  8. Helianthus annuus Leaf Ameliorates Postprandial Hyperglycaemia by Inhibiting Carbohydrate Hydrolyzing Enzymes Associated with Type-2 Diabetes

    Directory of Open Access Journals (Sweden)

    Oluwafemi Adeleke Ojo

    2016-08-01

    Full Text Available Background: Diabetes mellitus is a chronic disease. Decreasing postprandial hyperglycemia by retarding glucose absorption through inhibiting carbohydrates digesting enzymes (α-amylase and α-glucosidase is one of many approaches used for the management of this disease. This study was aimed at evaluating the normoglycaemic potential of Helianthus annuus leaf. Methods: The effect of the in vitro inhibitory of different extracts (acetone, ethyl acetate and hexane of the plant was assessed on the activities of diabetes-related enzymes (α-amylase and α-glucosidase. Results: The hexane extract of H. annuus leaf displayed the best inhibitory activity against α-amylase and α-glucosidase as indicated by the IC50 values (3.92 ± 0.02 mg mL-1 and (3.29 ± 0.12 mg mL-1, respectively. Lineweaver-Burk plot of inhibition of α-amylase and α-glucosidase by this extract showed that it was competitive and non-competitive mode, respectively. Conclusion: H. annuus leaf possesses hypoglycaemic potential which may be due to the inhibition of pancreatic α-amylase and intestinal α-glucosidase.

  9. Glutamate induces series of action potentials and a decrease in circumnutation rate in Helianthus annuus.

    Science.gov (United States)

    Stolarz, Maria; Król, Elzbieta; Dziubińska, Halina; Kurenda, Andrzej

    2010-03-01

    Reports concerning the function of glutamate (Glu) in the electrical and movement phenomena in plants are scarce. Using the method of extracellular measurement, we recorded electrical potential changes in the stem of 3-week-old Helianthus annuus L. plants after injection of Glu solution. Simultaneously, circumnutation movements of the stem were measured with the use of time-lapse images. Injection of Glu solution at millimolar (200, 50, 5 mM) concentrations in the basal part of the stem evoked a series of action potentials (APs). The APs appeared in the site of injection and in different parts of the stem and were propagated acropetally and/or basipetally along the stem. Glu injection also resulted in a transient, approximately 5-h-long decrease in the stem circumnutation rate. The APs initiated and propagating in the sunflower stem after Glu injection testify the existence of a Glu perception system in vascular plants and suggest its involvement in electrical, long-distance signaling. Our experiments also demonstrated that Glu is a factor affecting circumnutation movements.

  10. A time-series phytoremediation experiment with sunflowers (Helianthus annuus on a former uranium mining site

    Directory of Open Access Journals (Sweden)

    Kötschau A.

    2013-04-01

    Full Text Available On a test field situated at a former uranium mining site near Ronneburg (Thuringia, Germany a small scale time-series field experiment with sunflowers (Helianthus annuus was carried out. This area ghas elevated contents for the heavy metals Cd, Co, Cr, Cu, Ni, Zn including the radionuclides U and Th. Over a time period of 24 weeks the sunflowers were cultivated on homogenized soil substrate and regularly harvested. The aim was to find the ideal moment to harvest the sunflowers, being defined as having the best balance between the extraction of the contaminants and a high biomass produced. The contents of the elements were determined in soil, roots and above-ground plant parts. The contents in the above-ground plant showed no clear increasing or decreasing trend over time, so they were not the appropriate values to determine the best moment to harvest. Instead the total extracted masses (content in μg/g x biomass in g of the contaminants in the above-ground plant parts were calculated. According to this the best moment to harvest the sunflower plants was reached after 24 weeks of vegetation, because the highest extracted masses for all contaminants were calculated to this time. Additionally the biomass, which could be used e.g. for bio-fuel production, was highest at this time.

  11. Combined linkage and association mapping of flowering time in Sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Cadic, Elena; Coque, Marie; Vear, Felicity; Grezes-Besset, Bruno; Pauquet, Jerôme; Piquemal, Joël; Lippi, Yannick; Blanchard, Philippe; Romestant, Michel; Pouilly, Nicolas; Rengel, David; Gouzy, Jerôme; Langlade, Nicolas; Mangin, Brigitte; Vincourt, Patrick

    2013-05-01

    Association mapping and linkage mapping were used to identify quantitative trait loci (QTL) and/or causative mutations involved in the control of flowering time in cultivated sunflower Helianthus annuus. A panel of 384 inbred lines was phenotyped through testcrosses with two tester inbred lines across 15 location × year combinations. A recombinant inbred line (RIL) population comprising 273 lines was phenotyped both per se and through testcrosses with one or two testers in 16 location × year combinations. In the association mapping approach, kinship estimation using 5,923 single nucleotide polymorphisms was found to be the best covariate to correct for effects of panel structure. Linkage disequilibrium decay ranged from 0.08 to 0.26 cM for a threshold of 0.20, after correcting for structure effects, depending on the linkage group (LG) and the ancestry of inbred lines. A possible hitchhiking effect is hypothesized for LG10 and LG08. A total of 11 regions across 10 LGs were found to be associated with flowering time, and QTLs were mapped on 11 LGs in the RIL population. Whereas eight regions were demonstrated to be common between the two approaches, the linkage disequilibrium approach did not detect a documented QTL that was confirmed using the linkage mapping approach.

  12. HACRE1, a recently inserted copia-like retrotransposon of sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Buti, M; Giordani, T; Vukich, M; Gentzbittel, L; Pistelli, L; Cattonaro, F; Morgante, M; Cavallini, A; Natali, L

    2009-11-01

    In this paper we report on the isolation and characterization, for the first time, of a complete 6511 bp retrotransposon of sunflower. Considering its protein domain order and sequence similarity to other copia elements of dicotyledons, this retrotransposon was assigned to the copia retrotransposon superfamily and named HACRE1 (Helianthus annuus copia-like retroelement 1). HACRE1 carries 5' and 3' long terminal repeats (LTRs) flanking an internal region of 4661 bp. The LTRs are identical in their sequence except for two deletions of 7 and 5 nucleotides in the 5' LTR. Based on the sequence identity of the LTRs, HACRE1 was estimated to have inserted within the last approximately 84 000 years. The isolated sequence contains a complete open reading frame with only one complete reading frame. The absence of nonsense mutations agrees with the very high sequence identity between LTRs, confirming that HACRE1 insertion is recent. The haploid genome of sunflower (inbred line HCM) contains about 160 copies of HACRE1. This retrotransposon is expressed in leaflets from 7-day-old plantlets under different light conditions, probably in relation to the occurrence of many putative light-related regulatory cis-elements in the LTRs. However, sequenced cDNAs show less variability than HACRE1 genomic sequences, indicating that only a subset of this family is expressed under these conditions.

  13. Isolation and functional characterization of two novel seed-specific promoters from sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Zavallo, Diego; Lopez Bilbao, Marisa; Hopp, H Esteban; Heinz, Ruth

    2010-03-01

    The promoter region of two sunflower (Helianthus annuus L. HA89 genotype) seed specifically expressed genes, coding for an oleate desaturase (HaFAD2-1) and a lipid transfer protein (HaAP10), were cloned and in silico characterized. The isolated fragments are 867 and 964 bp long, respectively, and contain several seed-specific motifs, such as AACA motif, ACGT element, E-Boxes, SEF binding sites and GCN4 motif. Functional analysis of these promoters in transgenic Arabidopsis plants was investigated after fusing them with the beta-glucuronidase (GUS) reporter gene. None of the promoters triggered GUS activity in any vegetative tissue, with the exception of early seedling cotyledons. HaFAD2-1 and HaAP10 promoters were tested along seed development from globular stage to mature seeds. GUS staining was restricted to embryonic tissue and quantitative fluorometric assays showed high activity values at the later stages of development. In this work we demonstrate that HaFAD2-1 promoter is as strong as 35S promoter even though it is a tissue-specific promoter and its activity derived just from the embryo, thus confirming that it can be considered a strong highly specific seed promoter useful for biotechnology applications.

  14. Preparation of high-fructose syrup from the tubers of the Jerusalem artichoke (Helianthus tuberosus L.

    Science.gov (United States)

    Fleming, S E; GrootWassink, J W

    1979-11-01

    Fructose has recently received much attention due to renewed interest in natural sweeteners. In addition, fructose has some advantages to sucrose in sweetness, solubility, viscosity, and dental health characteristics. Fructose is deposited as storage fructans of the inulin (beta-1,2) type in tubers and rhizomes of the Compositae family. The utilization of the Jerusalem artichoke (Helianthus tuberosus) tuber as a source of fructose syrup is discussed. This plant has the potential to produce more sugar per acre than corn or sugar beets. In addition, the artichoke has higher frost resistance and lower heat unit requirements than corn and is somewhat more tolerant to low moisture conditions than sugar beets. A high quality fructose syrup can be produced from artichoke tubers. The extraction step was found to be particularly important since development of adverse colors and flavors must be prevented. The fructans may be acid or enzyme hydrolyzed but the latter method gave a higher quality syrup. Ion-exchange resins and activated charcoal were effective in removing coloring and flavoring materials, and also reduced other noncarbohydrate constituents. Since the enzymatic hydrolysis of the fructans is an attractive alternative to acid hydrolysis, a process was developed for producing and purifying a special beta-fructofuranosidase (inulase) from Saccharomyces fragilis. Inulase has a much higher specificity for fructans than commerically available beta-fructofuranosidase (invertase).

  15. From hybrid swarms to swarms of hybrids

    Science.gov (United States)

    Stohlgren, Thomas J.; Szalanski, Allen L; Gaskin, John F.; Young, Nicholas E.; West, Amanda; Jarnevich, Catherine S.; Tripodi, Amber

    2015-01-01

    Science has shown that the introgression or hybridization of modern humans (Homo sapiens) with Neanderthals up to 40,000 YBP may have led to the swarm of modern humans on earth. However, there is little doubt that modern trade and transportation in support of the humans has continued to introduce additional species, genotypes, and hybrids to every country on the globe. We assessed the utility of species distributions modeling of genotypes to assess the risk of current and future invaders. We evaluated 93 locations of the genus Tamarix for which genetic data were available. Maxent models of habitat suitability showed that the hybrid, T. ramosissima x T. chinensis, was slightly greater than the parent taxa (AUCs > 0.83). General linear models of Africanized honey bees, a hybrid cross of Tanzanian Apis mellifera scutellata and a variety of European honey bee including A. m. ligustica, showed that the Africanized bees (AUC = 0.81) may be displacing European honey bees (AUC > 0.76) over large areas of the southwestern U.S. More important, Maxent modeling of sub-populations (A1 and A26 mitotypes based on mDNA) could be accurately modeled (AUC > 0.9), and they responded differently to environmental drivers. This suggests that rapid evolutionary change may be underway in the Africanized bees, allowing the bees to spread into new areas and extending their total range. Protecting native species and ecosystems may benefit from risk maps of harmful invasive species, hybrids, and genotypes.

  16. Phytoextractor Potential of Cultivated Species in Industrial Area Contaminated by Lead

    OpenAIRE

    Silvânia Maria de Souza Gomes Nascimento; Adailson Pereira de Souza; Vera Lúcia Antunes de Lima; Clístenes Williams Araújo do Nascimento; Joab Josemar Vitor Ribeiro do Nascimento

    2016-01-01

    ABSTRACT: High growth rate is one of the criteria used for the selection of species to be used in metal phytoextraction programs. This study was carried out to characterize the growth characteristics of sunflower (Helianthus annuus L.), castor bean (Ricinus communis L.), corn (Zea mays L), and vetiver [Vetiveria zizanioides (L.) Nash] grown on a soil contaminated with lead (Pb), with and without pH correction, to improve agronomic practices regarding phytoremediation programs. The experiment ...

  17. Phytoextractor Potential of Cultivated Species in Industrial Area Contaminated by Lead

    OpenAIRE

    Silvânia Maria de Souza Gomes Nascimento; Adailson Pereira de Souza; Vera Lúcia Antunes de Lima; Clístenes Williams Araújo do Nascimento; Joab Josemar Vitor Ribeiro do Nascimento

    2016-01-01

    ABSTRACT: High growth rate is one of the criteria used for the selection of species to be used in metal phytoextraction programs. This study was carried out to characterize the growth characteristics of sunflower (Helianthus annuus L.), castor bean (Ricinus communis L.), corn (Zea mays L), and vetiver [Vetiveria zizanioides (L.) Nash] grown on a soil contaminated with lead (Pb), with and without pH correction, to improve agronomic practices regarding phytoremediation programs. The experiment ...

  18. Ants exhibit asymmetric hybridization in a mosaic hybrid zone.

    Science.gov (United States)

    Purcell, Jessica; Zahnd, Sacha; Athanasiades, Anouk; Türler, Rebecca; Chapuisat, Michel; Brelsford, Alan

    2016-10-01

    Research on hybridization between species provides unparalleled insights into the pre- and postzygotic isolating mechanisms that drive speciation. In social organisms, colony-level incompatibilities may provide additional reproductive barriers not present in solitary species, and hybrid zones offer an opportunity to identify these barriers. Here, we use genotyping-by-sequencing to sequence hundreds of markers in a hybrid zone between two socially polymorphic ant species, Formica selysi and Formica cinerea. We characterize the zone, determine the frequency of hybrid workers, infer whether hybrid queens or males are produced and investigate whether hybridization is influenced by colony social organization. We also compare cuticular hydrocarbon profiles and aggression levels between the two species. The hybrid zone exhibits a mosaic structure. The asymmetric distribution of hybrids skewed towards F. cinerea suggests a pattern of unidirectional nuclear gene flow from F. selysi into F. cinerea. The occurrence of backcrossed individuals indicates that hybrid queens and/or males are fertile, and the presence of the F. cinerea mitochondrial haplotype in 97% of hybrids shows that successful F1 hybrids will generally have F. cinerea mothers and F. selysi fathers. We found no evidence that social organization contributes to speciation, because hybrids occur in both single-queen and multiple-queen colonies. Strongly differentiated cuticular hydrocarbon profiles and heightened interspecific aggression further reveal that species recognition cues are both present and perceived. The discovery of fertile hybrids and asymmetrical gene flow is unusual in ants, and this hybrid zone will therefore provide an ideal system with which to investigate speciation in social insects.

  19. Development of sunflower hybrids tolerant to tribenuron methyl

    Directory of Open Access Journals (Sweden)

    Jocić Siniša

    2011-01-01

    Full Text Available Discovery of tribenuron-methyl resistant wild Helianthus annuus L. population (ANN-KAN created an opportunity for expansion of sunflower herbicide resistance breeding program. The aim of this study was development of sunflower hybrids resistant to tribenuron-methyl. Creation of tribenuron-methyl resistant hybrids would enable the use of a wider palette of herbicides for sunflower, more efficient chemical control of Cirsium arvense and more economically profitable post-emergence control of some annual broad-leaves weeds in sunflower. Original populations SURES-1 and SURES-2 are homozygous for resistance to tribenuron-methyl. F1 generations produced from the crossings are completely resistant to tribenuron-methyl, pointing out to dominant way of inheritance of this trait. Studies on the exact number of genes controlling the resistance are in progress. Tribenuron-methyl resistance was transferred from original populations into a number of female and male inbred lines of cultivated sunflower. These inbred lines could enable creation of a number of hybrids resistant to tribenuron-methyl. Hybrids SUMO-1-PR, SUMO-2- OR and SUMO-3 are resistant to doubled application dose of tribenuron-methyl. Agronomical characteristics of these hybrids are on the level with the leading conventional sunflower hybrids.

  20. Key bioactive reaction products of the NO/H2S interaction are S/N-hybrid species, polysulfides, and nitroxyl

    Science.gov (United States)

    Cortese-Krott, Miriam M.; Kuhnle, Gunter G. C.; Dyson, Alex; Fernandez, Bernadette O.; Grman, Marian; DuMond, Jenna F.; Barrow, Mark P.; McLeod, George; Nakagawa, Hidehiko; Ondrias, Karol; Nagy, Péter; King, S. Bruce; Saavedra, Joseph E.; Keefer, Larry K.; Singer, Mervyn; Kelm, Malte; Butler, Anthony R.; Feelisch, Martin

    2015-01-01

    Experimental evidence suggests that nitric oxide (NO) and hydrogen sulfide (H2S) signaling pathways are intimately intertwined, with mutual attenuation or potentiation of biological responses in the cardiovascular system and elsewhere. The chemical basis of this interaction is elusive. Moreover, polysulfides recently emerged as potential mediators of H2S/sulfide signaling, but their biosynthesis and relationship to NO remain enigmatic. We sought to characterize the nature, chemical biology, and bioactivity of key reaction products formed in the NO/sulfide system. At physiological pH, we find that NO and sulfide form a network of cascading chemical reactions that generate radical intermediates as well as anionic and uncharged solutes, with accumulation of three major products: nitrosopersulfide (SSNO−), polysulfides, and dinitrososulfite [N-nitrosohydroxylamine-N-sulfonate (SULFI/NO)], each with a distinct chemical biology and in vitro and in vivo bioactivity. SSNO− is resistant to thiols and cyanolysis, efficiently donates both sulfane sulfur and NO, and potently lowers blood pressure. Polysulfides are both intermediates and products of SSNO− synthesis/decomposition, and they also decrease blood pressure and enhance arterial compliance. SULFI/NO is a weak combined NO/nitroxyl donor that releases mainly N2O on decomposition; although it affects blood pressure only mildly, it markedly increases cardiac contractility, and formation of its precursor sulfite likely contributes to NO scavenging. Our results unveil an unexpectedly rich network of coupled chemical reactions between NO and H2S/sulfide, suggesting that the bioactivity of either transmitter is governed by concomitant formation of polysulfides and anionic S/N-hybrid species. This conceptual framework would seem to offer ample opportunities for the modulation of fundamental biological processes governed by redox switching and sulfur trafficking. PMID:26224837

  1. Metabolic and evolutionary insights into the closely-related species Streptomyces coelicolor and Streptomyces lividans deduced from high-resolution comparative genomic hybridization

    Directory of Open Access Journals (Sweden)

    Harrison Marcus

    2010-12-01

    Full Text Available Abstract Background Whilst being closely related to the model actinomycete Streptomyces coelicolor A3(2, S. lividans 66 differs from it in several significant and phenotypically observable ways, including antibiotic production. Previous comparative gene hybridization studies investigating such differences have used low-density (one probe per gene PCR-based spotted arrays. Here we use new experimentally optimised 104,000 × 60-mer probe arrays to characterize in detail the genomic differences between wild-type S. lividans 66, a derivative industrial strain, TK24, and S. coelicolor M145. Results The high coverage and specificity (detection of three nucleotide differences of the new microarrays used has highlighted the macroscopic genomic differences between two S. lividans strains and S. coelicolor. In a series of case studies we have validated the microarray and have identified subtle changes in genomic structure which occur in the Asp-activating adenylation domains of CDA non-ribosomal peptide synthetase genes which provides evidence of gene shuffling between these domains. We also identify single nucleotide sequence inter-species differences which exist in the actinorhodin biosynthetic gene cluster. As the glyoxylate bypass is non-functional in both S. lividans strains due to the absence of the gene encoding isocitrate lyase it is likely that the ethylmalonyl-CoA pathway functions as the alternative mechanism for the assimilation of C2 compounds. Conclusions This study provides evidence for widespread genetic recombination, rather than it being focussed at 'hotspots', suggesting that the previously proposed 'archipelago model' of genomic differences between S. coelicolor and S. lividans is unduly simplistic. The two S. lividans strains investigated differ considerably in genetic complement, with TK24 lacking 175 more genes than its wild-type parent when compared to S. coelicolor. Additionally, we confirm the presence of bldB in S. lividans and

  2. Enzymatic browning and after-cooking darkening of Jerusalem artichoke tubers (Helianthus tuberosus L.)

    DEFF Research Database (Denmark)

    Bach, Vibe; Bennedbæk-Jensen, Sidsel; Clausen, Morten Rahr

    2013-01-01

    Jerusalem artichoke tubers (Helianthus tuberosus L.) undergo enzymatic browning when peeled or cut, and turn grey after boiling, due to after-cooking darkening reactions between iron and phenolic acids. In an attempt to reveal the components responsible for these discolouration reactions, sensory...... evaluation and instrumental colour measurements were related to contents of total phenolics, phenolic acids, organic acids and iron in three varieties of raw and boiled Jerusalem artichoke tubers harvested in the autumn and the spring. No differences were found between varieties in sensory evaluated...

  3. Effect of antioxidant butylated hydroxyl anisole on the thermal or oxidative stability of sunflower oil (Helianthus Annuus) by ultrasonic

    OpenAIRE

    Murari, Satish Kumar; Shwetha, M. V.

    2015-01-01

    The aim of the current investigation was to evaluate the efficiency of butylated hydroxyl anisole (BHA) as an antioxidant in sunflower oil (Helianthus Annuus). The oxidation stability of sunflower oil have been investigated by the effects of varying amounts of BHA. The antioxidant incorporated sunflower oil system and control edible oil were subjected to heating at 180 ± 5 °C continuously for a period of 4 h per day for consecutive 4 days. The parameters used to assess the thermal degradation...

  4. Image Analysis of Geo-Induced Inhibition, Compression, and Promotion of Growth in an Inverted Helianthus annuus L. Seedling.

    Science.gov (United States)

    Gordon, D C; Macdonald, I R; Hart, J W; Berg, A

    1984-11-01

    The growth responses of a sunflower seedling (Helianthus annuus L.), subjected to repeated inversion, were characterized by time-lapse recording in conjunction with video image analysis. The investigation revealed a characteristic response pattern and established that the directional movement of the seedling is achieved by both inhibition and stimulation of growth in the normal growing regions. The complex growth changes in contiguous regions of the hypocotyl are such as seem to be inexplicable in terms of an environmentally imposed gradient of a single growth substance.

  5. Ectopic expression of the HAM59 gene causes homeotic transformations of reproductive organs in sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Shulga, O A; Neskorodov, Ya B; Shchennikova, A V; Gaponenko, A K; Skryabin, K G

    2015-01-01

    The function of the HAM59 MADS-box gene in sunflower (Helianthus annuus L.) was studied to clarify homeotic C activity in the Asteraceae plant family. For the first time, transgenic sunflower plants with a modified pattern of HAM59 expression were obtained. It was shown that the HAM59 MADS-box transcription factor did mediate C activity in sunflower. In particular, it participated in termination of the floral meristem, repression of the cadastral function of A-activity, and together with other C-type sunflower protein HAM45-in the specification of the identity of stamens and pistils.

  6. Components of phenotypic variability for head diameter in sunflower - Helianthus annuus L.

    Directory of Open Access Journals (Sweden)

    Hladni Nada

    2003-01-01

    Full Text Available Sunflower is the main crop species for the production of edible oil in many countries of the world, including ours. Plant height and head size, form and position on the stem as well as the number of leaves, their size, duration and distribution on the plant all play an important role in defining optimal plant architecture in sunflower hybrids (Škorić, 1975, 1989, 2002. In order to monitor the mode of inheritance and gene effects for head diameter in the F1 and F2 generations, half diallel crosses were made in six genetically divergent sunflower inbreds. The mean values of the trait in question differed significantly. The mode of inheritance of head diameter in the F1 generation was superdominance in all but four crosses, which had dominance instead. In the F2 generation, on the other hand, the prevailing mode was dominance, while superdominance was recorded in four cases. The dominant component accounted for the bulk of genetic variance, and the mode of inheritance of head diameter taking into account both the F1 and F2 generations was superdominance. These findings may prove valuable for developing high-yielding sunflower genotypes.

  7. Suborganellar localisation and effect of light on Helianthus tuberosus chloroplast transglutaminases and their substrates.

    Science.gov (United States)

    Dondini, L; Del Duca, S; Dall'Agata, L; Bassi, R; Gastaldelli, M; Della Mea, M; Di Sandro, A; Claparols, I; Serafini-Fracassini, D

    2003-05-01

    The light stimulation of transglutaminase (TGase EC 2.3.2.13) activity was verified by incubating isolated chloroplasts of Helianthus tuberosus L. continuously or for alternate periods of light or dark (light/dark and dark/light). The first 10 min of incubation always represented the critical period. Light-harvesting complexes of photosystem II (LHCII) were more intensely labelled by (14)C-polyamines under light and light/dark than under dark and dark/light conditions. Chloroplasts were fractionated into thylakoid- and stroma-enriched fractions in which multiple TGase forms and substrates were found. Antibodies against TGase recognised 58- and 24-kDa bands in thylakoids and a 150-kDa band in the stroma. The latter, and its 150-kDa fraction, catalysed the conjugation of 14C-polyamines to Rubisco. In both fractions (thylakoid-pre and stroma-pre) the analysis of polyamine glutamyl derivatives showed a significant light-affected conjugation of polyamines to endogenous proteins. Alternatively, entire chloroplasts were incubated and afterwards their sub-fractions were isolated (thylakoid-post and stroma-post). The PSII and LHCII complexes were more intensely immunodetected in thylakoid-post than in thylakoid-pre, especially under dark conditions. Conversely, the conjugation of polyamines to thylakoid proteins was clearly light-stimulated in thylakoid-post, and much less in thylakoid-pre. Stroma-pre proteins were poorly polyamine-conjugated and not light-affected; on the contrary, stroma-post proteins were much more polyamine-modified and strongly light-stimulated. Thus, the light-activated conjugation depends mainly on the presence of the thylakoid fraction during the assay. The protective effect on chloroplasts under photo-damage, stress or senescence conditions attributed in the literature to free polyamines is discussed with regard to the occurrence of polyamine conjugates catalysed by TGases.

  8. Response of sunflower (Helianthus annuus L.) leaf surface defenses to exogenous methyl jasmonate.

    Science.gov (United States)

    Rowe, Heather C; Ro, Dae-kyun; Rieseberg, Loren H

    2012-01-01

    Helianthus annuus, the common sunflower, produces a complex array of secondary compounds that are secreted into glandular trichomes, specialized structures found on leaf surfaces and anther appendages of flowers. The primary components of these trichome secretions are sesquiterpene lactones (STL), a diverse class of compounds produced abundantly by the plant family Compositae and believed to contribute to plant defense against herbivory. We treated wild and cultivated H. annuus accessions with exogenous methyl jasmonate, a plant hormone that mediates plant defense against insect herbivores and certain classes of fungal pathogens. The wild sunflower produced a higher density of glandular trichomes on its leaves than the cultivar. Comparison of the profiles of glandular trichome extracts obtained by liquid chromatography-mass spectroscopy (LC-MS) showed that wild and cultivated H. annuus were qualitatively similar in surface chemistry, although differing in the relative size and proportion of various compounds detected. Despite observing consistent transcriptional responses to methyl jasmonate treatment, we detected no significant effect on glandular trichome density or LC-MS profile in cultivated or wild sunflower, with wild sunflower exhibiting a declining trend in overall STL production and foliar glandular trichome density of jasmonate-treated plants. These results suggest that glandular trichomes and associated compounds may act as constitutive defenses or require greater levels of stimulus for induction than the observed transcriptional responses to exogenous jasmonate. Reduced defense investment in domesticated lines is consistent with predicted tradeoffs caused by selection for increased yield; future research will focus on the development of genetic resources to explicitly test the ecological roles of glandular trichomes and associated effects on plant growth and fitness.

  9. Response of sunflower (Helianthus annuus L. leaf surface defenses to exogenous methyl jasmonate.

    Directory of Open Access Journals (Sweden)

    Heather C Rowe

    Full Text Available Helianthus annuus, the common sunflower, produces a complex array of secondary compounds that are secreted into glandular trichomes, specialized structures found on leaf surfaces and anther appendages of flowers. The primary components of these trichome secretions are sesquiterpene lactones (STL, a diverse class of compounds produced abundantly by the plant family Compositae and believed to contribute to plant defense against herbivory. We treated wild and cultivated H. annuus accessions with exogenous methyl jasmonate, a plant hormone that mediates plant defense against insect herbivores and certain classes of fungal pathogens. The wild sunflower produced a higher density of glandular trichomes on its leaves than the cultivar. Comparison of the profiles of glandular trichome extracts obtained by liquid chromatography-mass spectroscopy (LC-MS showed that wild and cultivated H. annuus were qualitatively similar in surface chemistry, although differing in the relative size and proportion of various compounds detected. Despite observing consistent transcriptional responses to methyl jasmonate treatment, we detected no significant effect on glandular trichome density or LC-MS profile in cultivated or wild sunflower, with wild sunflower exhibiting a declining trend in overall STL production and foliar glandular trichome density of jasmonate-treated plants. These results suggest that glandular trichomes and associated compounds may act as constitutive defenses or require greater levels of stimulus for induction than the observed transcriptional responses to exogenous jasmonate. Reduced defense investment in domesticated lines is consistent with predicted tradeoffs caused by selection for increased yield; future research will focus on the development of genetic resources to explicitly test the ecological roles of glandular trichomes and associated effects on plant growth and fitness.

  10. Visitantes florales nocturnos del girasol (Helianthus annuus, Asterales: Asteraceae en la Argentina

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    Juan P TORRETTA

    2009-01-01

    Full Text Available El girasol (Helianthus annuus es un cultivo oleaginoso, polinizado por Apis mellifera L. y otras abejas en distintas regiones del mundo. Sin embargo, sus flores también son visitadas por insectos de actividad nocturna. Durante tres campañas agrícolas, se determinó la diversidad de los visitantes nocturnos de capítulos de girasol, en cinco sitios de Argentina. También se estudió el comportamiento de forrajeo de los principales visitantes y la variación de la receptividad estigmática a lo largo del día, con el fin de establecer si estos visitantes contribuyen a la polinización. Al menos 67 especies o morfoespecies pertenecientes a cuatro órdenes de visitantes nocturnos fueron colectadas. El orden más rico y abundante fue Lepidoptera (44 especies o morfoespecies, cinco familias, seguido por Coleoptera (18 especies o morfoespecies, nueve familias, Orthoptera (tres morfoespecies, una familia y Blattaria (dos especies, una familia. Los lepidópteros forrajearon exclusivamente por néctar, mientras que los individuos de los demás órdenes consumieron polen y/o partes florales. El estigma se encontró receptivo durante las horas de luz, con una receptividad máxima al mediodía (12:00 - 14:00. Llamativamente, las flores del girasol son visitadas por mayor número de polillas que de abejas. Debido a que las polillas consumen néctar y potencialmente transportan polen entre flores, en un momento del día en que los estigmas se encuentran menos receptivos, es improbable que polinicen efectivamente el cultivo.

  11. RNA-seq analysis and de novo transcriptome assembly of Jerusalem artichoke (Helianthus tuberosus Linne).

    Science.gov (United States)

    Jung, Won Yong; Lee, Sang Sook; Kim, Chul Wook; Kim, Hyun-Soon; Min, Sung Ran; Moon, Jae Sun; Kwon, Suk-Yoon; Jeon, Jae-Heung; Cho, Hye Sun

    2014-01-01

    Jerusalem artichoke (Helianthus tuberosus L.) has long been cultivated as a vegetable and as a source of fructans (inulin) for pharmaceutical applications in diabetes and obesity prevention. However, transcriptomic and genomic data for Jerusalem artichoke remain scarce. In this study, Illumina RNA sequencing (RNA-Seq) was performed on samples from Jerusalem artichoke leaves, roots, stems and two different tuber tissues (early and late tuber development). Data were used for de novo assembly and characterization of the transcriptome. In total 206,215,632 paired-end reads were generated. These were assembled into 66,322 loci with 272,548 transcripts. Loci were annotated by querying against the NCBI non-redundant, Phytozome and UniProt databases, and 40,215 loci were homologous to existing database sequences. Gene Ontology terms were assigned to 19,848 loci, 15,434 loci were matched to 25 Clusters of Eukaryotic Orthologous Groups classifications, and 11,844 loci were classified into 142 Kyoto Encyclopedia of Genes and Genomes pathways. The assembled loci also contained 10,778 potential simple sequence repeats. The newly assembled transcriptome was used to identify loci with tissue-specific differential expression patterns. In total, 670 loci exhibited tissue-specific expression, and a subset of these were confirmed using RT-PCR and qRT-PCR. Gene expression related to inulin biosynthesis in tuber tissue was also investigated. Exsiting genetic and genomic data for H. tuberosus are scarce. The sequence resources developed in this study will enable the analysis of thousands of transcripts and will thus accelerate marker-assisted breeding studies and studies of inulin biosynthesis in Jerusalem artichoke.

  12. COMPETENCIA POR INTERFERENCIA DE Helianthus annuus L., ASOCIADO A Solanum lycopersicum L. BAJO CONDICIONES DE CAMPO

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    Yaniuska González Perigó

    2014-01-01

    Full Text Available La investigación se realizó con el objetivo de determinar posibles competencias por interferencia de Helianthus annuus L. (girasol sobre Solanum lycopersicum L. (tomate en un sistema policultural en el período comprendido entre los meses de septiembre a diciembre durante dos años, en un agroecosistema montañoso de la provincia de Guantánamo, Cuba. Se estudiaron cuatro tratamientos: tomate monocultivo; girasol monocultivo; tomate asociado al girasol de forma simultánea y tomate 10 días antes, asociado al girasol. Los cultivos fueron establecidos en franjas de 150 m2. El tratamiento más eficiente (tomate 10 días antes, asociado al girasol fue repetido en el segundo año, manteniéndose además, los monocultivos de tomate y girasol. Se determinó el índice equivalente del uso de la tierra (IET, en base a los rendimientos, considerando además, el tiempo total de duración del sistema policultural (ATER. La mayor producción de tomate asociado al girasol se produjo cuando fue establecido 10 días antes. Como el valor de IET fue >1, puede atribuírsele beneficios económicos respecto al monocultivo, pero ATER alcanzó el valor 1,0, indicador de neutralidad. Sin embargo, desde el punto de vista ecológico este resultado constituye una opción aceptada dentro de la diversidad funcional, porque la asociación mejora el equilibrio del agroecosistema al aportar dos cultivos alimenticios simultáneos, lo que favorece el uso eficiente de los recursos del suelo y probable mejora en la composición de la entomofauna benéfica.

  13. Metal accumulation by sunflower (Helianthus annuus L.) and the efficacy of its biomass in enzymatic saccharification.

    Science.gov (United States)

    Dhiman, Saurabh Sudha; Zhao, Xin; Li, Jinglin; Kim, Dongwook; Kalia, Vipin C; Kim, In-Won; Kim, Jae Young; Lee, Jung-Kul

    2017-01-01

    Accumulation of metal contaminants in soil as a result of various industrial and anthropogenic activities has reduced soil fertility significantly. Phytoextraction of metal contaminants can improve soil fertility and provide inexpensive feedstock for biorefineries. We investigated the hyperaccumulation capacity of sunflower (Helianthus annuus) biomass by cultivating these plants in various concentrations of metal contaminants. Sunflowers were grown in soils contaminated with various levels of heavy metals (10-2,000 mg/kg dry soil). The degree of metal uptake by different parts of the biomass and the residual concentration in the soil were estimated through inductively coupled plasma mass spectrometry. An almost 2.5-fold hyperaccumulation of Zn2+ was observed in the leaf and flower biomass compared with the concentration in the soil. For the subsequent saccharification of biomass with hyperaccumulated contaminants, a fungal lignocellulosic consortium was used. The fungal consortium cocktail retained more than 95% filter paper activity with 100 mM Ni2+ ions even after 36 h. The highest saccharification yield (SY, 87.4%) was observed with Ni2+ as the contaminant (10 mg/kg dry wt), whereas Pb2+ (251.9 mg/kg dry wt) was the strongest inhibitor of biomass hydrolysis, resulting in only a 30% SY. Importantly, the enzyme cocktail produced by the fungal consortium resulted in almost the same SY (%) as that obtained from a combination of commercial cellulase and β-glucosidase. Significant sugar conversion (61.7%) from H. annuus biomass hydrolysate occurred, resulting in the production of 11.4 g/L of bioethanol. This is the first study to assess the suitability of phytoremediated sunflower biomass for bioethanol production.

  14. RNA-seq analysis and de novo transcriptome assembly of Jerusalem artichoke (Helianthus tuberosus Linne.

    Directory of Open Access Journals (Sweden)

    Won Yong Jung

    Full Text Available Jerusalem artichoke (Helianthus tuberosus L. has long been cultivated as a vegetable and as a source of fructans (inulin for pharmaceutical applications in diabetes and obesity prevention. However, transcriptomic and genomic data for Jerusalem artichoke remain scarce. In this study, Illumina RNA sequencing (RNA-Seq was performed on samples from Jerusalem artichoke leaves, roots, stems and two different tuber tissues (early and late tuber development. Data were used for de novo assembly and characterization of the transcriptome. In total 206,215,632 paired-end reads were generated. These were assembled into 66,322 loci with 272,548 transcripts. Loci were annotated by querying against the NCBI non-redundant, Phytozome and UniProt databases, and 40,215 loci were homologous to existing database sequences. Gene Ontology terms were assigned to 19,848 loci, 15,434 loci were matched to 25 Clusters of Eukaryotic Orthologous Groups classifications, and 11,844 loci were classified into 142 Kyoto Encyclopedia of Genes and Genomes pathways. The assembled loci also contained 10,778 potential simple sequence repeats. The newly assembled transcriptome was used to identify loci with tissue-specific differential expression patterns. In total, 670 loci exhibited tissue-specific expression, and a subset of these were confirmed using RT-PCR and qRT-PCR. Gene expression related to inulin biosynthesis in tuber tissue was also investigated. Exsiting genetic and genomic data for H. tuberosus are scarce. The sequence resources developed in this study will enable the analysis of thousands of transcripts and will thus accelerate marker-assisted breeding studies and studies of inulin biosynthesis in Jerusalem artichoke.

  15. Expression of different forms of transglutaminases by immature cells of Helianthus tuberosus sprout apices.

    Science.gov (United States)

    Beninati, Simone; Iorio, Rosa Anna; Tasco, Gianluca; Serafini-Fracassini, Donatella; Casadio, Rita; Del Duca, Stefano

    2013-01-01

    Immature cells of etiolated apices of sprouts growing from Helianthus tuberosus (H. t.) tubers showed Ca(2+)-dependent transglutaminase (TG, EC 2.3.2.13) activity on fibronectin (more efficiently) and dimethylcasein as substrates. Three main TG bands of about 85, 75 and 58 kDa were isolated from the 100,000×g apices supernatant through a DEAE-cellulose column at increasing NaCl concentrations and immuno-identified by anti-TG K and anti-rat prostate gland TG antibodies. These three fractions had catalytic activity as catalyzed polyamine conjugation to N-benzyloxycarbonyl-L-γ-glutaminyl-L-leucine (Z-L-Gln-L-Leu) and the corresponding glutamyl-derivatives were identified. The amino acid composition of these TG proteins was compared with those of several sequenced TGs of different origin. The composition of the two larger bands presented great similarities with annotated TGs; in particular, the 75 kDa form was very similar to mammalian inactive EPB42. The 58 kDa form shared a low similarity with other TGs, including a maize sequence of similar molecular mass, which, however, did not present the catalytic triad in the position of all annotated TGs. A 3D model of the H. t. TGs was built adopting TG2 as template. These novel plant TGs are hypothesized to be constitutive and discussed in relation to their possible roles in immature cells. These data suggest that in plants, multiple TG forms are active in the same organ and that plant and animal enzymes probably are very close not only for their catalytic activity but also structurally.

  16. Root water transport of Helianthus annuus L. under iron oxide nanoparticle exposure.

    Science.gov (United States)

    Martínez-Fernández, Domingo; Barroso, Didac; Komárek, Michael

    2016-01-01

    The application of nanomaterials in commercially available products is increasing rapidly for agriculture, phytoremediation and biotechnology. Since plants suppose the first sink for the accumulation of nanoparticles from the environment, emerging studies have focused on the general consequences for plants and their effects on the biomass production. However, effects on the root surface, as well as blockage of nutrients and water uptake by the roots, may also occur. This experiment was designed to prove if the plant water relations can be affected by the adsorption of nanoparticles on the root surface, causing a consequent stress for the plants. With this goal, plants of Helianthus annuus were previously grown in a hydroponic culture, and at age of 55 days, their roots were exposed to three different concentrations of nanomaghemite (NM) in the hydroponic solution for 5 days: control without NM; 50 and 100 mg l(-1) NM. The main effect was related to the reduction of the root hydraulic conductivity (Lo) and the nutrients uptake. The concentrations of the macronutrients Ca, K, Mg and S in the shoot were reduced relative to the control plants, which resulted in lower contents of chlorophyll pigments. Although stress was not detected in the plants, after the analysis of stress markers like the accumulation of proline or ascorbate in the tissues, reduction of the root functionality by nanoparticles has been identified here, manifested as the effect of NM on Lo. The treatment with 50 mg l(-1) NM significantly reduced the Lo, by up to 57% of its control value, and it was reduced by up to 26% at 100 mg l(-1) NM. These results will be an important factor to take into account with regard to the applicability of NM for long-term use in crops, particularly during privative water conditions.

  17. Biologically active antimicrobial and antioxidant substances in the Helianthus annuus L. bee pollen.

    Science.gov (United States)

    Fatrcová-Šramková, Katarína; Nôžková, Janka; Máriássyová, Magda; Kačániová, Miroslava

    2016-01-01

    The objective of this study was to measure the content of flavonoids, polyphenols, and carotenoids in the Helianthus annuus L. bee pollen. It was also to evaluate the ability of the dried, frozen, and freeze-dried extracts of sunflower (H. annuus) pollen, its scavenged free radicals and reducing action. Another aim of this study was to investigate the antimicrobial in vitro action of the H. annuus pollen extracts against the Gram-positive and Gram-negative bacteria and fungi. All pollen extracts showed medium antiradical activity and reductive ability. The most effective was the freeze-dried extract in both evaluation systems. The evaluation of the protective effects of DNA using a biosensor showed an opposite trending-frozen ˃ dried ˃ freeze-dried pollen. For the evaluation of antiradical activity, the DPPH method was used, and reductive ability was assessed by means of phosphomolybdic complex formation. The comparison of the polyphenols content shows higher values in freeze-dried bee pollen than in the dried and frozen pollen. The highest content of flavonoids was found in the frozen samples and the most carotenoids were present in the dried samples. In our study, the best antibacterial effects of the dried sunflower bee pollen extracts were found against Paenibacillus larvae, Pseudomonas aeruginosa, and Enterococcus raffinosus. The best inhibitory properties of the frozen sunflower bee pollen extracts were found against Escherichia coli, Pseudomonas aeruginosa, and Paenibacillus larvae. Very good inhibitory effects of freeze-dried sunflower bee pollen were found against Paenibacillus larvae, Brochotrix thermosphacta, and Enterococcus raffinosus. The best antifungal activity of the sunflower bee pollen was found in the frozen bee pollen extracts against Aspergillus ochraceus and freeze-dried bee pollen extracts against Aspergillus niger.

  18. Physiology and proteomics of drought stress acclimation in sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Fulda, S; Mikkat, S; Stegmann, H; Horn, R

    2011-07-01

    An easy and manageable in vitro screening system for drought tolerance of sunflower seedlings based on MS media supplemented with polyethylene glycol 6000 was evaluated. Morphological and physiological parameters were compared between control (-0.05 MPa) and drought-stressed (-0.6 MPa) seedlings of Helianthus annuus L. cv. Peredovick. There was a significant growth deficit in drought-stressed plants compared to control plants in terms of hypocotyl length, and shoot and root fresh mass. Shoot growth was more restricted than root growth, resulting in an increased root/shoot ratio of drought-stressed plants. Accumulation of osmolytes such as inositol (65-fold), glucose (58-fold), proline (55-fold), fructose (11-fold) and sucrose (eightfold), in leaves of drought-stressed plants could be demonstrated by gas-liquid chromatography. Soluble protein patterns of leaves were analysed with two-dimensional gel electrophoresis (2D-PAGE) and MALDI-TOF mass spectrometry. A set of 46 protein spots allowed identification of 19 marker proteins. Quantitative changes in protein expression of drought-stressed versus control plants were detected. In leaves of drought-stressed sunflower seedlings six proteins were significantly up-regulated more than twofold: a putative caffeoyl-CoA 3-O-methyltransferase (4.5-fold), a fructokinase 3 (3.3-fold), a vegetative storage protein (2.5-fold), a glycine-rich RNA binding protein (2.2-fold), a CuZn-superoxide dismutase (2.1-fold) and an unknown low molecular weight protein (2.3-fold). These proteins represent general stress proteins induced under drought conditions or proteins contributing to basic carbon metabolism. The up-regulated proteins are interesting candidates for further physiological and molecular investigations regarding drought tolerance in sunflower.

  19. Light intensity alters the extent of arsenic toxicity in Helianthus annuus L. seedlings.

    Science.gov (United States)

    Yadav, Geeta; Srivastava, Prabhat Kumar; Singh, Vijay Pratap; Prasad, Sheo Mohan

    2014-06-01

    The present study is aimed at assessing the extent of arsenic (As) toxicity under three different light intensities-optimum (400 μmole photon m(-2) s(-1)), sub-optimum (225 μmole photon m(-2) s(-1)), and low (75 μmole photon m(-2) s(-1))-exposed to Helianthus annuus L. var. DRSF-113 seedlings by examining various physiological and biochemical parameters. Irrespective of the light intensities under which H. annuus L. seedlings were grown, there was an As dose (low, i.e., 6 mg kg(-1) soil, As1; and high, i.e., 12 mg kg(-1) soil, As2)-dependent decrease in all the growth parameters, viz., fresh mass, shoot length, and root length. Optimum light-grown seedlings exhibited better growth performance than the sub-optimum and low light-grown seedlings; however, low light-grown plants had maximum root and shoot lengths. Accumulation of As in the plant tissues depended upon its concentration used, proximity of the plant tissue, and intensity of the light. Greater intensity of light allowed greater assimilation of photosynthates accompanied by more uptake of nutrients along with As from the medium. The levels of chlorophyll a, b, and carotenoids declined with increasing concentrations of As. Seedlings acquired maximum Chl a and b under optimum light which were more compatible to face As1 and As2 doses of As, also evident from the overall status of enzymatic (SOD, POD, CAT, and GST) and non-enzymatic antioxidant (Pro).

  20. Pollen aroma fingerprint of two sunflower (Helianthus annuus L.) genotypes characterized by different pollen colors.

    Science.gov (United States)

    Bertoli, Alessandra; Fambrini, Marco; Doveri, Silvia; Leonardi, Michele; Pugliesi, Claudio; Pistelli, Luisa

    2011-09-01

    Samples of fresh pollen grains, collected from capitula in full bloom from two genotypes of sunflower (Helianthus annuus L.) and characterized by a different color, i.e., white-cream (WC) and orange (O), were analyzed by the HS-SPME (headspacesolid phase microextraction)/GC/MS technique. This study defined for the first time the fingerprint of the sunflower pollen, separated from the disc flowers, to define its contribution to the inflorescence aroma. In the GC/MS fingerprints of the WC and O genotypes, 61 and 62 volatile compounds were identified, respectively. Monoterpene hydrocarbons (34% in O vs. 28% in WC) and sesquiterpene hydrocarbons (37% in O vs. 31% in WC) were ubiquitous in all samples analyzed and represented the main chemical classes. α-Pinene (21% in O vs. 20% in WC) and sabinene (11% in O vs. 6% in WC) were the dominant volatiles, but also a full range of aliphatic hydrocarbons and their oxygenated derivatives gave a decisive contribution to the aroma composition (10% in O vs. 12% in WC). In addition, dendrolasin (3% in O vs. 4% in WC) and some minor constituents such as (E)-hex-2-en-1-ol (0.4% in O vs. 0.1% in WC) were pointed out not only for their contribution to the pollen scent, but also for their well-known role in the plant ecological relationships. Having evaluated two pollen morphs with different carotenoid-based colors, the study sought to highlight also the presence of some volatile precursors or derivatives of these pigments in the aroma. However, the pollen aroma of the two selected genotypes made a specific chemical contribution to the sunflower inflorescence scent without any influence on carotenoid derivatives.

  1. Cross-species bacterial artificial chromosome (BAC) library screening via overgo-based hybridization and BAC-contig mapping of a yield enhancement quantitative trait locus (QTL) yld1.1 in the Malaysian wild rice Oryza rufipogon.

    Science.gov (United States)

    Song, Beng-Kah; Nadarajah, Kalaivani; Romanov, Michael N; Ratnam, Wickneswari

    2005-01-01

    The construction of BAC-contig physical maps is an important step towards a partial or ultimate genome sequence analysis. Here, we describe our initial efforts to apply an overgo approach to screen a BAC library of the Malaysian wild rice species, Oryza rufipogon. Overgo design is based on repetitive element masking and sequence uniqueness, and uses short probes (approximately 40 bp), making this method highly efficient and specific. Pairs of 24-bp oligos that contain an 8-bp overlap were developed from the publicly available genomic sequences of the cultivated rice, O. sativa, to generate 20 overgo probes for a 1-Mb region that encompasses a yield enhancement QTL yld1.1 in O. rufipogon. The advantages of a high similarity in melting temperature, hybridization kinetics and specific activities of overgos further enabled a pooling strategy for library screening by filter hybridization. Two pools of ten overgos each were hybridized to high-density filters representing the O. rufipogon genomic BAC library. These screening tests succeeded in providing 69 PCR-verified positive hits from a total of 23,040 BAC clones of the entire O. rufipogon library. A minimal tilling path of clones was generated to contribute to a fully covered BAC-contig map of the targeted 1-Mb region. The developed protocol for overgo design based on O. sativa sequences as a comparative genomic framework, and the pooled overgo hybridization screening technique are suitable means for high-resolution physical mapping and the identification of BAC candidates for sequencing.

  2. Research on Extraction of Inulin from Helianthus tuberosus L.%菊芋菊糖的提取研究

    Institute of Scientific and Technical Information of China (English)

    姜少娟

    2012-01-01

    The extraction of inulin from Helianthus tuberosus L. was studied. The inulin was extracted from Helian-thus tuberosus L. by solvent extraction. The extraction process of inulin was optimized with single factor experiment and or-thogonal experiment. The results indicated that optimum extraction conditions were determined as follows: stock ratio 1 : 15(mass : volume), temperature 70 ℃, time 90 min, and 3 times.%对菊芋菊糖的提取工艺条件进行了研究。采用浸提法提取菊芋中的菊糖,以单因素试验法和正交试验法确定了菊糖提取的最佳工艺条件。结果表明,菊芋菊糖的最佳提取工艺条件为料液比1:15,在70℃时提取90min,共提取三次。

  3. Analysis of Phenolic Acids of Jerusalem Artichoke (Helianthus tuberosus L. Responding to Salt-Stress by Liquid Chromatography/Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Fujia Chen

    2014-01-01

    Full Text Available Plant phenolics can have applications in pharmaceutical and other industries. To identify and quantify the phenolic compounds in Helianthus tuberosus leaves, qualitative analysis was performed by a reversed phase high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS and quantitative analysis by HPLC. Ten chlorogenic acids (CGAs were identified (3-o-caffeoylquinic acid, two isomers of caffeoylquinic acid, caffeic acid, p-coumaroyl-quinic acid, feruloylquinic acid, 3,4-dicaffeoyquinic acid, 3,5-dicaffeoylquinic acid, 1,5-dicaffeoylquinic acid, and 4,5-dicaffeoylquinic acid by comparing their retention times, UV-Vis absorption spectra, and MS/MS spectra with standards. In addition, four other phenolic compounds, including caffeoyl glucopyranose, isorhamnetin glucoside, kaempferol glucuronide, and kaempferol-3-o-glucoside, were tentatively identified in Helianthus tuberosus leaves for the first time. The 3-o-caffeoylquinic acid (7.752 mg/g DW, 4,5-dicaffeoylquinic acid (5.633 mg/g DW, and 3,5-dicaffeoylquinic acid (4.900 mg/g DW were the major phenolic compounds in leaves of Helianthus tuberosus cultivar NanYu in maturity. The variations in phenolic concentrations and proportions in Helianthus tuberosus leaves were influenced by genotype and plant growth stage. Cultivar NanYu had the highest concentration of phenolic compounds, in particular 3-o-caffeoylquinic acid and 4,5-dicaffeoylquinic acid compared with the other genotypes (wild accession and QingYu. Considering various growth stages, the concentration of total phenolics in cultivar NanYu was higher at flowering stage (5.270 mg/g DW than at budding and tuber swelling stages. Cultivar NanYu of Helianthus tuberosus is a potential source of natural phenolics that may play an important role in the development of pharmaceuticals.

  4. Molecular evidence for hybridization in Colias (Lepidoptera: Pieridae): are Colias hybrids really hybrids?

    Science.gov (United States)

    Dwyer, Heather E; Jasieniuk, Marie; Okada, Miki; Shapiro, Arthur M

    2015-01-01

    Gene flow and hybridization among species dramatically affect our understanding of the species as a biological unit, species relationships, and species adaptations. In North American Colias eurytheme and Colias eriphyle, there has been historical debate over the extent of hybridization occurring and the identity of phenotypically intermediate individuals as genetic hybrids. This study assesses the population structure of these two species to measure the extent of hybridization and the genetic identity of phenotypic intermediates as hybrids. Amplified fragment length polymorphism (AFLP) marker analysis was performed on 378 specimens collected from northern California and Nevada. Population structure was inferred using a Bayesian/Markov chain Monte Carlo method, which probabilistically assigns individuals to genetic clusters. Three genetic clusters provided the best fit for the data. C. eurytheme individuals were primarily assigned to two closely related clusters, and C. eriphyle individuals were mostly assigned to a third, more distantly related cluster. There appeared to be significant hybridization between the two species. Individuals of intermediate phenotype (putative hybrids) were found to be genetically indistinguishable from C. eriphyle, indicating that previous work based on the assumption that these intermediate forms are hybrids may warrant reconsideration. PMID:26306172

  5. Hybrid Baryons

    CERN Document Server

    Page, P R

    2003-01-01

    We review the status of hybrid baryons. The only known way to study hybrids rigorously is via excited adiabatic potentials. Hybrids can be modelled by both the bag and flux-tube models. The low-lying hybrid baryon is N 1/2^+ with a mass of 1.5-1.8 GeV. Hybrid baryons can be produced in the glue-rich processes of diffractive gamma N and pi N production, Psi decays and p pbar annihilation.

  6. Effect of Nitrogen Supply on the Nitrogen Use Efficiency of an Annual Herb, Helianthus annuus L.

    Institute of Scientific and Technical Information of China (English)

    Zhi-You YUAN; Ling-Hao LI; Jian-Hui HUANG; Xing-Guo HAN; Shi-Qiang WAN

    2005-01-01

    Nitrogen use efficiency (NUE) is the product of nitrogen productivity (NP) and the mean residence time of nitrogen (MRT). Theory suggests that there should be a trade-off between both components,but direct experimental evidence is still scarce. To test this hypothesis, we analyzed the effect of varying nitrogen supply levels on NUEand its two components (NP, MRT) in Helianthus annuus L., an annual herb.The plants investigated were subjected to six nitrogen levels (0, 2, 4, 8, 16, and 32 g N/m2). Total plant production increased substantially with increasing nitrogen supply. Nitrogen uptake and loss also in creased with nitrogen supply. Nitrogen influx (rin) and outflux (rout) were defined as the rates of nitrogen uptake and loss per unit aboveground nitrogen, respectively. Both rin and rout increased with increasing nitrogen supply. In addition, rin was far higher than rout. Consequently, the relative rate of nitrogen incre ment (rin- rout) also increased with nitrogen supply. There were marked differences between treatments with respect to parameters related to the stress resistance syndrome: nitrogen pool size, leaf nitrogen concentration,and net aboveground productivity increased with nitrogen supply. Plants at high nitrogen levels showed a higher NP (the growth rate per unit aboveground nitrogen) and a shorter MRT (the inverse of rout), whereas plants at low nitrogen levels displayed the reverse pattern. Shorter MRT for plants at high nitrogen levels was caused by the abscission of leaves that contained relatively large fractions of total plant nitrogen. We found a negative relationship between NP and MRT, the components of NUE, along the gradient of nitrogen availability, suggesting that there was a trade-off between NP and MRT. The NUE increased with increasing nitrogen availability, up to a certain level, and then decreased. These results offer support for the hypoth esis that adaptation to infertile habitats involves a low nitrogen loss (long MRT in the

  7. The physiological and biochemical effects of salicylic acid on sunflowers (Helianthus annuus) exposed to flurochloridone.

    Science.gov (United States)

    Kaya, Armagan; Yigit, Emel

    2014-08-01

    In this study, we comparatively evaluated the effects of the flurochloridone as well as flurochloridone and exogenously applied salicylic acid (SA) on Helianthus annuus L. to find out herbicide-induced toxicity reducing influence of SA. We examined and compared the physiological and biochemical effects of different concentrations of flurochloridone (11, 32 and 72 mM) in both the SA pre-treated and non-treated plants. The plants treated with flurochloridone exhibited reduced total chlorophyll, carotenoid, and relative water content compared to the control group, whereas the plants that were pre-treated with SA exhibited relatively higher values for the same physiological parameters. In the SA non-treated plants, the superoxide dismutase, glutathione reductase and glutathione S-transferase activities were increased in the treatment groups compared to the control group. In the treatment groups, these enzyme activities were decreased in the SA-pre-treated plants compared to the non-treated plants. Ascorbate peroxidase and catalase activities decreased in the flurochloridone-treated plants compared to the control plants. The ascorbate peroxidase activity increased in the control groups but decreased in the treatment groups in the SA pre-treated plants compared to the non-treated plants. However, SA treatment decreased the activity of catalase in the control and treatment groups compared to the plants that were not treated with SA. Flurochloridone treatment increased the malondialdehyde content in the treated groups compared to the control groups, whereas SA-pretreatment decreased malondialdehyde content compared to plants that were not treated with SA. Flurochloridone treatment increased endogenous SA content compared to the control. Although the residual levels of herbicide in the plants increased proportionately with increasing herbicide concentrations, the SA-pre-treated plants exhibited reduced residual herbicide levels compared to the plants that were not treated

  8. Identification of candidate genes associated with leaf senescence in cultivated sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Moschen, Sebastian; Bengoa Luoni, Sofia; Paniego, Norma B; Hopp, H Esteban; Dosio, Guillermo A A; Fernandez, Paula; Heinz, Ruth A

    2014-01-01

    Cultivated sunflower (Helianthus annuus L.), an important source of edible vegetable oil, shows rapid onset of senescence, which limits production by reducing photosynthetic capacity under specific growing conditions. Carbon for grain filling depends strongly on light interception by green leaf area, which diminishes during grain filling due to leaf senescence. Transcription factors (TFs) regulate the progression of leaf senescence in plants and have been well explored in model systems, but information for many agronomic crops remains limited. Here, we characterize the expression profiles of a set of putative senescence associated genes (SAGs) identified by a candidate gene approach and sunflower microarray expression studies. We examined a time course of sunflower leaves undergoing natural senescence and used quantitative PCR (qPCR) to measure the expression of 11 candidate genes representing the NAC, WRKY, MYB and NF-Y TF families. In addition, we measured physiological parameters such as chlorophyll, total soluble sugars and nitrogen content. The expression of Ha-NAC01, Ha-NAC03, Ha-NAC04, Ha-NAC05 and Ha-MYB01 TFs increased before the remobilization rate increased and therefore, before the appearance of the first physiological symptoms of senescence, whereas Ha-NAC02 expression decreased. In addition, we also examined the trifurcate feed-forward pathway (involving ORE1, miR164, and ethylene insensitive 2) previously reported for Arabidopsis. We measured transcription of Ha-NAC01 (the sunflower homolog of ORE1) and Ha-EIN2, along with the levels of miR164, in two leaves from different stem positions, and identified differences in transcription between basal and upper leaves. Interestingly, Ha-NAC01 and Ha-EIN2 transcription profiles showed an earlier up-regulation in upper leaves of plants close to maturity, compared with basal leaves of plants at pre-anthesis stages. These results suggest that the H. annuus TFs characterized in this work could play important

  9. Molecular tagging of a novel rust resistance gene R(12) in sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Gong, L; Hulke, B S; Gulya, T J; Markell, S G; Qi, L L

    2013-01-01

    Sunflower production in North America has recently suffered economic losses in yield and seed quality from sunflower rust (Puccinia helianthi Schwein.) because of the increasing incidence and lack of resistance to new rust races. RHA 464, a newly released sunflower male fertility restorer line, is resistant to both of the most predominant and most virulent rust races identified in the Northern Great Plains of the USA. The gene conditioning rust resistance in RHA 464 originated from wild Helianthus annuus L., but has not been molecularly marked or determined to be independent from other rust loci. The objectives of this study are to identify molecular markers linked to the rust resistance gene and to investigate the allelism of this gene with the unmapped rust resistance genes present in HA-R6, HA-R8 and RHA 397. Virulence phenotypes of seedlings for the F(2) population and F(2:3) families suggested that a single dominant gene confers rust resistance in RHA 464, and this gene was designated as R(12). Bulked segregant analysis identified ten markers polymorphic between resistant and susceptible bulks. In subsequent genetic mapping, the ten markers covered 33.4 cM of genetic distance on linkage group 11 of sunflower. A co-dominant marker CRT275-11 is the closest marker distal to R(12) with a genetic distance of 1.0 cM, while ZVG53, a dominant marker linked in the repulsion phase, is proximal to R(12) with a genetic distance of 9.6 cM. The allelism test demonstrated that R(12) is not allelic to the rust resistance genes in HA-R6, HA-R8 and RHA 397, and it is also not linked to any previously mapped rust resistance genes. Discovery of the R(12) novel rust resistance locus in sunflower and associated markers will potentially support the molecular marker-assisted introgression and pyramiding of R(12) into sunflower breeding lines.

  10. How common is homoploid hybrid speciation?

    Science.gov (United States)

    Schumer, Molly; Rosenthal, Gil G; Andolfatto, Peter

    2014-06-01

    Hybridization has long been considered a process that prevents divergence between species. In contrast to this historical view, an increasing number of empirical studies claim to show evidence for hybrid speciation without a ploidy change. However, the importance of hybridization as a route to speciation is poorly understood, and many claims have been made with insufficient evidence that hybridization played a role in the speciation process. We propose criteria to determine the strength of evidence for homoploid hybrid speciation. Based on an evaluation of the literature using this framework, we conclude that although hybridization appears to be common, evidence for an important role of hybridization in homoploid speciation is more circumscribed.

  11. Dendrochilum hampelii (Coelogyninae, Epidendroideae, Orchidaceae) traded as ‘Big Pink’ is a new species, not a hybrid: evidence from nrITS, matK and ycf1 sequence data

    Science.gov (United States)

    Sulistyo, Bobby P.; Boos, Ronny; Cootes, James E.; Gravendeel, Barbara

    2015-01-01

    Abstract In 2013, an unidentified species of Dendrochilum appeared in cultivation under the commercial trade name ‘Big Pink’. Using sequences of the nuclear ribosomal ITS1-5.8S-ITS2 region and of the plastid matK and ycf1 genes, we examined the phylogenetic relationships between ‘Big Pink’ and six other species of the phenetically defined Dendrochilum subgen. Platyclinis sect. Eurybrachium. Separate and combined analyses (using Bayesian, Maximum Likelihood and Parsimony inference) showed consistent placement of the unidentified species within a statistically well supported clade. Furthermore, the multi-copy nrITS marker showed clear distinct peaks. Thus, we found no evidence that ‘Big Pink’ could be a hybrid. Against this background, and further supported by species-specific mutations in (at least) nrITS and ycf1, we formally describe ‘Big Pink’ as a new species under the name Dendrochilum hampelii. Morphologically, it is most similar to Dendrochilum propinquum, but it differs in a number of characters. Of the two cultivated individuals available for our study, one was of unrecorded provenance. The other allegedly originated from the Philippines. Observations of the species occurring in the wild in the Philippines in the northern provinces of Bukidnon and Misamis Oriental on the island of Mindanao confirmed this. PMID:26491388

  12. Dendrochilum hampelii (Coelogyninae, Epidendroideae, Orchidaceae) traded as 'Big Pink' is a new species, not a hybrid: evidence from nrITS, matK and ycf1 sequence data.

    Science.gov (United States)

    Sulistyo, Bobby P; Boos, Ronny; Cootes, James E; Gravendeel, Barbara

    2015-01-01

    In 2013, an unidentified species of Dendrochilum appeared in cultivation under the commercial trade name 'Big Pink'. Using sequences of the nuclear ribosomal ITS1-5.8S-ITS2 region and of the plastid matK and ycf1 genes, we examined the phylogenetic relationships between 'Big Pink' and six other species of the phenetically defined Dendrochilum subgen. Platyclinis sect. Eurybrachium. Separate and combined analyses (using Bayesian, Maximum Likelihood and Parsimony inference) showed consistent placement of the unidentified species within a statistically well supported clade. Furthermore, the multi-copy nrITS marker showed clear distinct peaks. Thus, we found no evidence that 'Big Pink' could be a hybrid. Against this background, and further supported by species-specific mutations in (at least) nrITS and ycf1, we formally describe 'Big Pink' as a new species under the name Dendrochilum hampelii. Morphologically, it is most similar to Dendrochilum propinquum, but it differs in a number of characters. Of the two cultivated individuals available for our study, one was of unrecorded provenance. The other allegedly originated from the Philippines. Observations of the species occurring in the wild in the Philippines in the northern provinces of Bukidnon and Misamis Oriental on the island of Mindanao confirmed this.

  13. Evaluation of two hybrid poplar clones as constructed wetland plant species for treating saline water high in boron and selenium, or waters only high in boron

    Science.gov (United States)

    Wetland mesocosms were constructed to assess two salt- and B-tolerant hybrid poplar clones (Populus trichocarpa ×P. deltoides×P. nigra '345-1' and '347-14') for treating saline water high in boron (B) and selenium (Se). In addition, a hydroponic experiment was performed to test the B tolerance and B...

  14. The effect of genes on A and B chromosomes of a number of Triticinae on meiotic behaviour in Triticum aestivum and its hybrids with related species

    NARCIS (Netherlands)

    Viegas, W.S.

    1979-01-01

    Results obtained and hypotheses that have been put forward to integrate them, are summarized in this section.1. Studies of chromosome association in F 1 hybrids Triticum aestivum X Secale cereale with and without chromosome 5B and in the presence or in the absence o

  15. Physiological Adaptation and Invasion Success: A Comparison of Native and Invasive Species of Bay Mussels in the Central California Hybrid Zone

    OpenAIRE

    Somero, George N.

    2005-01-01

    Invasive aquatic species can pose serious ecological and economic threats to coastal habitats. Although the mechanisms by which invasive species are introduced are generally well understood, and frequently caused by discharging ballast water, less is known about the physiological characterists that allow an invasive species to proliferate so successfully.

  16. Hybridization in geese: a review

    OpenAIRE

    Ottenburghs, Jente; Van Hooft, Pim; van Wieren, Sipke E.; Ydenberg, Ronald C; Herbert H. T. Prins

    2016-01-01

    The high incidence of hybridization in waterfowl (ducks, geese and swans) makes this bird group an excellent study system to answer questions related to the evolution and maintenance of species boundaries. However, knowledge on waterfowl hybridization is biased towards ducks, with a large knowledge gap in geese. In this review, we assemble the available information on hybrid geese by focusing on three main themes: (1) incidence and frequency, (2) behavioural mechanisms leading to hybridizatio...

  17. THE RELATIONSHIP BETWEEN HETEROSIS AND GENETIC DISTANCES BASED ON SSR MARKERS IN HELIANTHUS ANNUUS

    Directory of Open Access Journals (Sweden)

    A. V. Usatov

    2014-01-01

    Full Text Available Identifying the best inbred combinations for the development of commercial hybrid of sunflower remains the main challenge to sunflower breeders. In the present research the level of heterosis of F1 hybrids, genetic diversity of parental lines based on SSR markers, as well as its connection with specific combining ability of sunflower were studied. Ten sunflower elite inbred lines (3 restorer lines and 7 cytoplasmic male sterility lines and their hybrids were examined for plant height, seed yield, thousand seed mass, oil content and husk content. Field tests were carried out in 5-6 seasons. The level of heterosis was calculated using measurement of midparent heterosis. Genetic distance between pairs of tested sunflower inbred lines ranged from 0.45 to 0.74. Significant positive correlation was found between genetic distances among lines, measured using SSR markers and midparent heterosis for seed yield of hybrids (r = 0.79 p<0.05. The correlation between genetic distances and the level of midparent heterosis for other studied agronomic traits was not reliable. The dependence of seed yield of hybrids on genetic distances among parental lines may be used for planning of effective crossbreeding of sunflower. Further research is needed to determine the best inbred combinations for the development of commercial hybrid of sunflower.

  18. Identification and quantification of Bifidobacterium species isolated from food with genus-specific 16S rRNA-targeted probes by colony hybridization and PCR.

    Science.gov (United States)

    Kaufmann, P; Pfefferkorn, A; Teuber, M; Meile, L

    1997-01-01

    A Bifidobacterium genus-specific target sequence in the V9 variable region of the 16S rRNA has been elaborated and was used to develop a hybridization probe. The specificity of this probe, named lm3 (5'-CGGGTGCTI*CCCACTTTCATG-3'), was used to identify all known type strains and distinguish them from other bacteria. All of the 30 type strains of Bifidobacterium which are available at the German culture collection Deutsche Sammlung von Mikroorganismen und Zellkulturen, 6 commercially available production strains, and 34 closely related relevant strains (as negative controls) were tested. All tested bifidobacteria showed distinct positive signals by colony hybridization, whereas all negative controls showed no distinct dots except Gardnerella vaginalis DSM4944 and Propionibacterium freudenreichii subsp. shermanii DSM4902, which gave slight signals. Furthermore, we established a method for isolation and identification of bifidobacteria from food by using a PCR assay without prior isolation of DNA but breaking the cells with proteinase K. By this method, all Bifidobacterium strains lead to a DNA product of the expected size. We also established a quick assay to quantitatively measure Bifidobacterium counts in food and feces by dilution plating and colony hybridization. We were able to demonstrate that 2.1 x 10(6) to 2.3 x 10(7) colonies/g of sour milk containing bifidobacteria hybridized with the specific nucleotide probe. With these two methods, genus-specific colony hybridization and genus-specific PCR, it is now possible to readily and accurately detect any bifidobacteria in food and fecal samples and to discriminate between them and members of other genera. PMID:9097423

  19. The potential of Zea mays, Commelina bengelensis, Helianthus annuus and Amaranthus hybridus for phytoremediation of waste water

    Directory of Open Access Journals (Sweden)

    Chacha Joseph Sarima

    2012-12-01

    Full Text Available Waste-water from domestic use and from industrial effluent burden the water systems with high levels of heavy metal hence there is need to remove these heavy metals so that the waste water can be recycled for use for household or irrigation. The present study has screened Zea mays (maize, Commelina bengelensis (wondering jew, Helianthus annuus (sunflower and Amaranthus hybridus (amaranthus for their ability to bioaccumulate Pb, Cu, Cd and Zn metals. The results obtained show that the H. annuus and C. bengelensis plant have promising potential for removal of Pb, Cu and Cd from wastewater though their ability to remove Zn from contaminated solutions is not much different from that of Z. mays and A. hybridus.

  20. Influence of silver and titanium nanoparticles on arbuscular mycorrhizal colonization and accumulation of radiocaesium in Helianthus annuus

    Energy Technology Data Exchange (ETDEWEB)

    Dubchak, S.; Ogar, A.; Mietelski, J. W.; Turnau, K.

    2010-07-01

    The influence of albacore's mycorrhizal fungus on {sup 1}34Cs uptake by Helianthus annuus was studied in a pilot study under growth chamber conditions. Mycorrhizal plants took up five times more {sup 1}34Cs (up to 250,000 Bq kg{sup -}1 dry weight) than non mycorrhizal plants. Silver and titanium nanoparticles, supplied into the surface soil layer decreased both the mycorrhizal colonization and Cs uptake by mycorrhizal plants. The application of activated carbon attenuated the effect of nanoparticles and increased {sup 1}34Cs uptake in the presence of mycorrhizal fungi (up to 400,000 Bq kg{sup -}1 dry weight). The results underline the possible application of phyto remediation techniques based on mycorrhizas assisted plants in decontamination of both radionuclides and nanoparticles. (Author) 27 refs.

  1. Linearity assumption in soil-to-plant transfer factors of natural uranium and radium in Helianthus annuus L

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, P. Blanco [Departamento de Fisica, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz (Spain); Tome, F. Vera [Departamento de Fisica, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz (Spain)]. E-mail: fvt@unex.es; Fernandez, M. Perez [Area de Ecologia, Departamento de Fisica, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz (Spain); Lozano, J.C. [Laboratorio de Radiactividad Ambiental, Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca (Spain)

    2006-05-15

    The linearity assumption of the validation of soil-to-plant transfer factors of natural uranium and {sup 226}Ra was tested using Helianthus annuus L. (sunflower) grown in a hydroponic medium. Transfer of natural uranium and {sup 226}Ra was tested in both the aerial fraction of plants and in the overall seedlings (roots and shoots). The results show that the linearity assumption can be considered valid in the hydroponic growth of sunflowers for the radionuclides studied. The ability of sunflowers to translocate uranium and {sup 226}Ra was also investigated, as well as the feasibility of using sunflower plants to remove uranium and radium from contaminated water, and by extension, their potential for phytoextraction. In this sense, the removal percentages obtained for natural uranium and {sup 226}Ra were 24% and 42%, respectively. Practically all the uranium is accumulated in the roots. However, 86% of the {sup 226}Ra activity concentration in roots was translocated to the aerial part.

  2. [Adaptability of Helianthus annuus seedlings to crude oil pollution in soil and its improvement measures under salinization stress].

    Science.gov (United States)

    Zhang, Jing-lei; Ci, Hua-cong; He, Xing-dong; Liang, Yu-ting; Zhao, Xuan; Sun, Hui-ting; Xie, Hong-tao

    2015-11-01

    To explore the adaptability of plant under salt stress to crude oil pollution of soil and improvement measures, a pot experiment of Helianthus annuus seedlings was conducted using orthogonal experiment method with crude oil-sodium chloride-desulfurization gypsum and cinder-zeolite-desulfurization gypsum-sawdust. The results showed that, with the increase of soil crude oil concentration, the relative growth rate (RGR) of plant height, RGR of aboveground biomass and root N: P ratios of H. annuus seedlings decreased significantly, while the activity of SOD and CAT increased at first and then decreased significantly. The RGR of plant height and aboveground biomass significantly increased (P cinder, zeolite, desulfurization gypsum under salinization condition. The crude oil pollution of soil could decrease the relative growth rate of H. annuus seedling, and sawdust could reduce the influence of crude oil pollution on plant growth under salt stress.

  3. The content of protein and of amino acids in Jerusalem artichoke tubers (Helianthus tuberosus L. of red variety Rote Zonenkugel

    Directory of Open Access Journals (Sweden)

    Ewa Cieślik

    2011-12-01

    Full Text Available   Introduction. Jerusalem artichoke (Helianthus tuberosus L. is grown primarily for its edible tubers, which were first cultivated by native Americans before the arrival of the Europeans. Unlike most tubers, but in common with other members of the Asteraceae, the tubers store fructans instead of starch. Fructans are non-digestible carbohydrates considered functional food ingredients because they affect body processes in ways that result in better health and in many diseases prevention. However, the Jerusalem artichoke deserves attention not only because of the content of fructans, recent studies also indicate a high protein content, including essential amino acids. Material and methods. The aim of the work was to establish the content of protein and amino acids in Jerusalem artichoke tubers (Helianthus tuberosus L. of red variety – Rote Zonenkugel. The content of protein was estimated by Dumas method. The amino acids composition was analysed with ion-change chromatography with postcolumn derivatisation and detection of ninhydryn reaction with automatic amino acids analyser. Results. The assessed liophylisate was characterised by high protein content (6.36% in comparison to chicory (which is the main industrial source of fructans and to commonly consumed potatoes. There was shown a few times higher content of essential amino acids (also of methionine in comparison to chicory and potato. The examined essential amino acids were present in very advantagenous proportions. Conclusions. In Jerusalem artichoke tubers of Rote Zonenkugel variety of the high content of protein was established in comparison to other plant sources. The high content was found of amino acids with special stress on essential amino acids (esp. sulphur ones.  

  4. The content of protein and of amino acids in Jerusalem artichoke tubers (Helianthus tuberosus L.) of red variety Rote Zonenkugel.

    Science.gov (United States)

    Cieślik, Ewa; Gębusia, Agnieszka; Florkiewicz, Adam; Mickowska, Barbara

    2011-01-01

    Jerusalem artichoke (Helianthus tuberosus L.) is grown primarily for its edible tubers, which were first cultivated by native Americans before the arrival of the Europeans. Unlike most tubers, but in common with other members of the Asteraceae, the tubers store fructans instead of starch. Fructans are non-digestible carbohydrates considered functional food ingredients because they affect body processes in ways that result in better health and in many diseases prevention. However, the Jerusalem artichoke deserves attention not only because of the content of fructans, recent studies also indicate a high protein content, including essential amino acids. The aim of the work was to establish the content of protein and amino acids in Jerusalem artichoke tubers (Helianthus tuberosus L.) of red variety--Rote Zonenkugel. The content of protein was estimated by Dumas method. The amino acids composition was analysed with ion-change chromatography with postcolumn derivatisation and detection of ninhydryn reaction with automatic amino acids analyser. The assessed liophylisate was characterised by high protein content (6.36%) in comparison to chicory (which is the main industrial source of fructans) and to commonly consumed potatoes. There was shown a few times higher content of essential amino acids (also of methionine) in comparison to chicory and potato. The examined essential amino acids were present in very advantagenous proportions. In Jerusalem artichoke tubers of Rote Zonenkugel variety of the high content of protein was established in comparison to other plant sources. The high content was found of amino acids with special stress on essential amino acids (esp. sulphur ones).

  5. Reproduction and hybrid load in all-hybrid populations of Rana esculenta water frogs in Denmark

    DEFF Research Database (Denmark)

    Christiansen, Ditte Guldager; Fog, Kåre; Pedersen, Bo Vest;

    2005-01-01

    All-hybrid populations of the water frog, Rana esculenta, are exceptional in consisting of independently and to some extent sexually reproducing interspecific hybrids. In most of its range R. esculenta reproduces hemiclonally with one of the parental species, R. lessonae or R. ridibunda, but viable...... gametogenesis and mating between frogs with incompatible gametes induce a significant hybrid load in all-hybrid populations of R. esculenta, and we discuss compensating advantages and potential evolutionary trajectories to reduce this hybrid load....

  6. Efficient new constructs against triple negative breast cancer cells: synthesis and preliminary biological study of ferrocifen-SAHA hybrids and related species.

    Science.gov (United States)

    Cázares Marinero, José de Jesús; Lapierre, Marion; Cavaillès, Vincent; Saint-Fort, Rénette; Vessières, Anne; Top, Siden; Jaouen, Gérard

    2013-11-21

    Chemotherapeutic agents combining several active groups within a single molecule can modulate multiple cellular pathways and, thus, exhibit higher efficacy than single-target drugs. In this study, six new hybrid compounds combining tamoxifen (TAM) or ferrocifen (FcTAM) structural motifs with suberoylanilide hydroxamic acid (SAHA) were synthesised and evaluated. Antiproliferative activity was first explored in cancer cell lines. Combining FcTAM and SAHA structural motifs to form the unprecedented FcTAM–SAHA hybrid molecule led to an increased cytotoxicity (IC50 = 0.7 μM) in triple-negative MDA-MB-231 breast cancer cells when compared to FcTAM or SAHA alone (IC50 = 2.6 μM and 3.6 μM, respectively), while the organic hybrid analogue TAM–SAHA was far less cytotoxic (IC50 = 8.6 μM). In hormone-dependent MCF-7 breast cancer cells, FcTAM–SAHA was more active (IC50 = 2.0 μM) than FcTAM (IC50 = 4.4 μM) and TAM–SAHA (IC50 > 10 μM), but less toxic than SAHA (IC50 = 1.0 μM). Surprisingly, FcTAM–PSA, an N1-phenylsuberamide derivative, also possessed strong antiproliferative activity (IC50 = 0.5 μM and 1.8 μM in MDA-MB-231 and MCF-7 cells, respectively). Subsequent biochemical studies indicate that estrogen receptor alpha (ERα) and histone deacetylases (HDAC) are not the main targets of the hybrid compounds for their antiproliferative effect. Interestingly, both organometallic compounds were able to induce p21waf1/cip1 gene expression in MCF-7 breast cancer cells in accordance with their antiproliferative activity.

  7. Accurate and Practical Identification of 20 Fusarium Species by Seven-Locus Sequence Analysis and Reverse Line Blot Hybridization, and an In Vitro Antifungal Susceptibility Study▿†

    Science.gov (United States)

    Wang, He; Xiao, Meng; Kong, Fanrong; Chen, Sharon; Dou, Hong-Tao; Sorrell, Tania; Li, Ruo-Yu; Xu, Ying-Chun

    2011-01-01

    Eleven reference and 25 clinical isolates of Fusarium were subject to multilocus DNA sequence analysis to determine the species and haplotypes of the fusarial isolates from Beijing and Shandong, China. Seven loci were analyzed: the translation elongation factor 1 alpha gene (EF-1α); the nuclear rRNA internal transcribed spacer (ITS), large subunit (LSU), and intergenic spacer (IGS) regions; the second largest subunit of the RNA polymerase gene (RPB2); the calmodulin gene (CAM); and the mitochondrial small subunit (mtSSU) rRNA gene. We also evaluated an IGS-targeted PCR/reverse line blot (RLB) assay for species/haplotype identification of Fusarium. Twenty Fusarium species and seven species complexes were identified. Of 25 clinical isolates (10 species), the Gibberella (Fusarium) fujikuroi species complex was the commonest (40%) and was followed by the Fusarium solani species complex (FSSC) (36%) and the F. incarnatum-F. equiseti species complex (12%). Six FSSC isolates were identified to the species level as FSSC-3+4, and three as FSSC-5. Twenty-nine IGS, 27 EF-1α, 26 RPB2, 24 CAM, 18 ITS, 19 LSU, and 18 mtSSU haplotypes were identified; 29 were unique, and haplotypes for 24 clinical strains were novel. By parsimony informative character analysis, the IGS locus was the most phylogenetically informative, and the rRNA gene regions were the least. Results by RLB were concordant with multilocus sequence analysis for all isolates. Amphotericin B was the most active drug against all species. Voriconazole MICs were high (>8 μg/ml) for 15 (42%) isolates, including FSSC. Analysis of larger numbers of isolates is required to determine the clinical utility of the seven-locus sequence analysis and RLB assay in species classification of fusaria. PMID:21389150

  8. Hybrid vehicles

    Energy Technology Data Exchange (ETDEWEB)

    West, J.G.W. [Electrical Machines (United Kingdom)

    1997-07-01

    The reasons for adopting hybrid vehicles result mainly from the lack of adequate range from electric vehicles at an acceptable cost. Hybrids can offer significant improvements in emissions and fuel economy. Series and parallel hybrids are compared. A combination of series and parallel operation would be the ideal. This can be obtained using a planetary gearbox as a power split device allowing a small generator to transfer power to the propulsion motor giving the effect of a CVT. It allows the engine to run at semi-constant speed giving better fuel economy and reduced emissions. Hybrid car developments are described that show the wide range of possible hybrid systems. (author)

  9. Monograph of Arctium L. (Asteraceae). Generic delimitation (including Cousinia Cass, p.p.), revision of the species, pollen morphology, and hybrids

    NARCIS (Netherlands)

    Duistermaat, Helena

    1996-01-01

    The subject of this thesis is a monograph of the genus Arctium, now including also five species formerly placed into Cousinia. Based on herbarium material and some field observations, this study presents new insights on three subjects: a) the generic delimitation of Arctium, b) the species

  10. Monograph of Arctium L. (Asteraceae). Generic delimitation (including Cousinia Cass, p.p.), revision of the species, pollen morphology, and hybrids

    NARCIS (Netherlands)

    Duistermaat, Helena

    1996-01-01

    The subject of this thesis is a monograph of the genus Arctium, now including also five species formerly placed into Cousinia. Based on herbarium material and some field observations, this study presents new insights on three subjects: a) the generic delimitation of Arctium, b) the species delimitat

  11. Hybridization and the evolution of reef coral diversity.

    Science.gov (United States)

    Vollmer, Steven V; Palumbi, Stephen R

    2002-06-14

    Hundreds of coral species coexist sympatrically on reefs, reproducing in mass-spawning events where hybridization appears common. In the Caribbean, DNA sequence data from all three sympatric Acropora corals show that mass spawning does not erode species barriers. Species A. cervicornis and A. palmata are distinct at two nuclear loci or share ancestral alleles. Morphotypes historically given the name Acropora prolifera are entirely F(1) hybrids of these two species, showing morphologies that depend on which species provides the egg for hybridization. Although selection limits the evolutionary potential of hybrids, F(1) individuals can reproduce asexually and form long-lived, potentially immortal hybrids with unique morphologies.

  12. Detecting hybridization using ancient DNA.

    Science.gov (United States)

    Schaefer, Nathan K; Shapiro, Beth; Green, Richard E

    2016-06-01

    It is well established that related species hybridize and that this can have varied but significant effects on speciation and environmental adaptation. It should therefore come as no surprise that hybridization is not limited to species that are alive today. In the last several decades, advances in technologies for recovering and sequencing DNA from fossil remains have enabled the assembly of high-coverage genome sequences for a growing diversity of organisms, including many that are extinct. Thanks to the development of new statistical approaches for detecting and quantifying admixture from genomic data, genomes from extinct populations have proven useful both in revealing previously unknown hybridization events and informing the study of hybridization between living organisms. Here, we review some of the key recent statistical innovations for detecting ancient hybridization using genomewide sequence data and discuss how these innovations have revised our understanding of human evolutionary history.

  13. Increasing the productivity of biomass plantations of Populus species and hybrids in the Pacific Northwest. Final report, September 14, 1981--December 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    DeBell, D.S.; Harrington, C.A.; Clendenen, G.W. [USDA Forest Service, Olympia, WA (United States)] [and others

    1997-08-01

    This final report represents the culmination of eight years of biological research devoted to increasing the productivity of short rotation plantations of Populus trichocarpa and Populus hybrids in the Pacific Northwest. Studies described herein provide an understanding of tree growth, stand development and biomass yield at various spacings, and how patterns thereof differ by Populus clone in monoclonal and polyclonal plantings. Also included is some information about factors related to wind damage in Populus plantings, use of leaf size as a predictor of growth potential, and approaches for estimating tree and stand biomass and biomass growth. The work was accomplished in three research plantations, all established cooperatively with the Washington State Department of Natural Resources (DNR) and located at the DNR Tree Improvement Center near Olympia. The first plantation was established in Spring 1986 to evaluate the highly touted {open_quotes}woodgrass{close_quotes} concept and compare it with more conventional short-rotation management regimes, using two Populus hybrid clones planted at five spacings. Besides providing scientific data to resolve the politicized {open_quotes}wood-grass{close_quotes} dispute, this plantation has furnished excellent data on stand dynamics and woody biomass yield. A second plantation was established at the same time; groups of trees therein received two levels of irrigation and different amounts of four fertilizer amendments, resulting in microsites with diverse moisture and nutrient conditions.

  14. Simultaneous identification of Aspergillus and Mucorales species by reverse line blot (RLB) hybridization assay%应用反向线点杂交技术鉴定临床常见曲霉属和毛霉目真菌

    Institute of Scientific and Technical Information of China (English)

    赵作涛; 李丽丽; 王晓阳; 万喆; 陈伟; 李若瑜

    2011-01-01

    Objective To Rapidly differentiate Aspergillus and Mucorales species by reverse line blot hybridization (RLB). Methods Totally 98 isolates including five Aspergillus strains ( Aspergillus fumigatus, Aspergillus flavus,Aspergillus niger, Aspergillus terreus and Aspergillus nidulans ) and seven Mucorales species ( Mucor heimalis ,Mucor racemosus ,Mucor cercinelloidea,Rhizopus arrhizus,Rhizopus microsporus,Rhizomucor pusillus and Absidia corymbifera ) were obtained from Research Center for Medical Mycology and Mycoses, Peking University. ITS1 and ITS4 fungal universal primers were chosen for PCR amplification, and the amplified products were used for reverse line blot hybridization with 12 fungal specie-specific probes. RLB data were compared with those by traditional fungal morphology and ITS sequencing methods. Results RLB showed high sensitivity and specificity , with 100% correct identification percentage of all the isolates and no cross hybridization between the species-specific probes. Eight negative control stains ( Candida albicans ,Fusarium solani ,Scedosporium apiospermum ,Penicillium marneffei ,Exophiala verrucosa,Aspergillus clavatus,Aspergillus japonicus and Cunninghamella elegans ) also showed negative by RLB. The analytical sensitivity of RLB was 1. 8 x 10-3 ng/μL by 10-fold serial dilution of Aspergillus fumigatus genomic DNA. Conclusions The RLB assay provides a rapid and reliable option for laboratory diagnosis and identification of Aspergillus and Mucorales species.%目的 应用反向线点杂交技术(reverse line blot hybridization,RLB)快速鉴定临床常见的曲霉属和毛霉目真菌.方法 收集我院真菌和真菌病研究中心保存的5种曲霉菌(烟曲霉、黄曲霉、黑曲霉、土曲霉、构巢曲霉)和7种毛霉目真菌(冻土毛霉菌、总状毛霉菌、卷枝毛霉菌、少根根霉、小孢根霉、微小根毛霉、伞状犁头霉),共计98株菌株.利用真菌通用引物ITS1和ITS4对菌株进行PCR扩增,用12个

  15. 黑籽南瓜种间杂交研究%Research of Distant Hybridization Between Fig-leaf Gourd (Cucurbita ficifolia)and Three Mainly Cultivated Species in Cucurbita

    Institute of Scientific and Technical Information of China (English)

    马海龙; 智海英; 岳青

    2011-01-01

    Asynchronous flowering period in different species of Cucurbits was overcome by the means of adjusting sowing time. The experiment of interspecific hybridization was done between 12 materials of three mainly cultivated species (C. Pepo, C. Moschata and C. Maxima) and fig-leaf gourd (C. Ficifolia.). It was no fruit when the fig-leaf gourd act as female parent, and it was fruiting when the other three mainly cultivated species did. There were no seeds in the fruits when C. pepoxC. Gcifolia and C. maximaxC. Gcifolia. 18 Fi plants of C. moschataxC. Gcifolia were obtained. The stamens were degenerate in the plants of the interspecific hybrids Fi. It was fruiting but no seeds when the interspecific hybrids Fi as female parent and backcrossing using C. Moschata or the C. Gcifolia as male parent. The plant morphology of Fi of C. Moschata X C. Gcifolia was intermediate type of parents and had a tendency to the male parent. Disease resistance and insect resistance of the Fi were worse than C. Gcifolia of male parent and approached C. Moschata of female parent.%通过调整播期克服了南瓜属种间花期不遇的问题,以美洲南瓜、中国南瓜、印度南瓜3个种共12个材料与黑籽南瓜进行了种间杂交试验.黑籽南瓜为母本不结实,以其他3个种为母本则均可结实.美洲南瓜×黑籽南瓜及印度南瓜×黑籽南瓜杂交获得的果实内均无种子.获得了18株中国南瓜×黑籽南瓜F1植株.种间杂种F1植株雄蕊退化,以其作为母本以中国南瓜或黑籽南瓜为父本进行回交,可结实但无种子.中国南瓜×黑籽南瓜F1形态为双亲中间型偏父本,其抗病性、抗虫性不及父本黑籽南瓜而倾向于母本中国南瓜.

  16. Species conservation-based hybrid algorithm for reversible circuit synthesis%基于子种群保留的可逆电路合成混合算法

    Institute of Scientific and Technical Information of China (English)

    王潇潇; 焦李成; 李阳阳

    2015-01-01

    为了进一步降低4 bit以上中小规模可逆逻辑电路的量子代价,提出一种基于子种群保留的变长染色体编码混合算法。该算法在已有变长染色体编码混合算法的基础上,将子种群保留策略用于变长编码种群的进化,以保持种群多样性,避免陷入局部最优解;定义了变长编码染色体的近似度,以此作为种子提取和子种群划分的基础;提出了子种群重新启动策略和新的启发式子种群更新操作,克服变长编码种群进化过程中的遗传漂移,从而提高可行解率和解的质量。对4 bit以上常用标准可逆函数测试结果表明该算法能大大降低合成可逆电路的量子代价。%In order to decrease the quantum cost of small and medium‐sized reversible functions with more than 4 bit ,a species conservation‐based variable‐length encoding hybrid algorithm for reversible logic circuit synthesis was proposed based on an existing variable‐length encoding hybrid algorithm . Firstly ,the species conservation mechanism was customized and introduced into variable‐length enco‐ding population to maintain the diversity of the population .The similarity definition between chromo‐somes with different lengths was given ,based on which seeds subtraction and species differentiation were conducted .Then ,the species restart strategy and heuristic species update were proposed to a‐void the genetic draft of the population with variable‐length encoding .The experimental results show that the proposed algorithm can reduce the quantum cost of common reversible benchmarks and im‐prove the feasible ratio greatly .

  17. Correlation and path coefficient analysis for protein yield in confectionary sunflower (Helianthus annuus L.)

    OpenAIRE

    Hladni Nada; Miklič Vladimir; Mijić Anto; Jocić Siniša; Miladinović Dragana

    2015-01-01

    The most important criteria for introducing new confectionary hybrids into the production is high protein yield. Path coefficient analysis was used to obtain information on direct and indirect effects of studied traits (seed oil content, kernel oil content, seed yield, kernel protein content, mass of 1000 seeds, kernel ratio and hull ratio) on protein yield. The research was conducted during three vegetation seasons, on 22 experimental confectionary sunflow...

  18. Extended X-ray absorption fine structure studies of Zn2Fe2 hybrid hemoglobins: absence of heme bond length changes in half-ligated species.

    Science.gov (United States)

    Simolo, K; Korszun, Z R; Stucky, G; Moffat, K; McLendon, G; Bunker, G

    1986-07-01

    Metal hybrid hemoglobins, in which Zn(II) replaces Fe(II), have been structurally characterized by extended X-ray absorption structure (EXAFS) studies. Since Zn and Fe have very different K absorption edge energies, the structures of the ligated (Fe) and unligated (Zn) sites could be examined independently within a single molecule that mimics an intermediate ligation state. The observed EXAFS spectra and associated structural parameters are compared among the ligand free (alpha Zn)2(beta Zn)2, half-ligated (alpha FeCO)2(beta Zn)2 and (alpha Zn)2(beta FeCO)2, and fully ligated (alpha FeCO)2(beta FeCO)2 systems.

  19. Hybridization in a warmer world.

    Science.gov (United States)

    Chunco, Amanda J

    2014-05-01

    Climate change is profoundly affecting the evolutionary trajectory of individual species and ecological communities, in part through the creation of novel species assemblages. How climate change will influence competitive interactions has been an active area of research. Far less attention, however, has been given to altered reproductive interactions. Yet, reproductive interactions between formerly isolated species are inevitable as populations shift geographically and temporally as a result of climate change, potentially resulting in introgression, speciation, or even extinction. The susceptibility of hybridization rates to anthropogenic disturbance was first recognized in the 1930s. To date, work on anthropogenically mediated hybridization has focused primarily on either physical habitat disturbance or species invasion. Here, I review recent literature on hybridization to identify how ecological responses to climate change will increase the likelihood of hybridization via the dissolution of species barriers maintained by habitat, time, or behavior. Using this literature, I identify several cases where novel hybrid zones have recently formed, likely as a result of changing climate. Future research should focus on identifying areas and taxonomic groups where reproductive species interactions are most likely to be influenced by climate change. Furthermore, a better understanding of the evolutionary consequences of climate-mediated secondary contact is urgently needed. Paradoxically, hybridization is both a major conservation concern and an important source of novel genetic and phenotypic variation. Hybridization may therefore both contribute to increasing rates of extinction and stimulate the creation of novel phenotypes that will speed adaptation to novel climates. Predicting which result will occur following secondary contact will be an important contribution to conservation for many species.

  20. A Review of Jerusalem Artichoke(Helianthus tuberosus L.)Developing in Qinghai Plateau%青海高原菊芋(Helianthus tuberosus L.)开发研究述评

    Institute of Scientific and Technical Information of China (English)

    黄相国; 葛菊梅; 沈裕虎; 王海庆; 张怀刚

    2004-01-01

    对在青海高原开发野菜资源菊芋(Helianthus tuberosus L.)进行了述评.介绍了菊芋的生物学和生态学特性,栽培管理方法.菊芋块茎富含菊糖,经现代生物技术深加工后,可得菊粉(Inulin).再以菊粉为原料经菊粉酶(Inulinase EC3.2.1.7)水解可制成低聚果糖(Oligosaccharides)、超高果糖浆(Ultrahigh fructose Glucose Syrups UHFGS).菊粉、低聚果糖、超高果糖浆都是当今食品工业的一种全新的多功能配料,是全水溶性膳食纤维,同时还是双歧杆菌增殖因子,应用前景非常广阔.

  1. Studies on Morphology of F1 Hybrid and Systematic Evolution of Epimedium Species%淫羊藿属植物杂交F1代植株形态和种间系统演化研究

    Institute of Scientific and Technical Information of China (English)

    杜明凤; 陈庆富

    2013-01-01

    淫羊藿属植物多数种类在形态分类性状上存在连续过渡的形态变异现象,导致种间的鉴别困难.本研究对粗毛淫羊藿、巫山淫羊藿、天平淫羊藿,3个物种合计29个居群之间的种间杂交F1代植株及其亲本形态学进行了比较研究.结果表明:AC×MY、AC×WU、WU×MY 3种组合杂交F1代的叶片形状表现为双亲过渡形态,控制淫羊藿花瓣距短于内萼片的基因可能是部分显性,E.acuminatum的花瓣和内萼片颜色属于显性遗传.所得结果为淫羊藿属植物分类学、种间系统关系及其起源与进化研究提供了新的资料和线索.%It is known that there are continuous variations of morphological characteristics for taxonomy among most Epimedium species,leading to difficulties of species identification.The morphology of interspecific F1 hybrid plants among 29 populations of E.acuminatum,E.wushanese and E.myrianthum was studied comparatively.The results shows that the length of flower calcar shorter than the inner sepal may be controlled by partly-dominant gene,and the leaf shape of hybrid F1 progenies are the middle type between the parents.The colour of the inner sepal and flower calcar in E.acuminatum is controlled by dominant genes.These above results are useful on interspecific hybridization and variety improvement on Epimedium.

  2. Reaction of tomato hybrids carrying the Ty-1 locus to Brazilian bipartite Begomovirus species Resposta de híbridos de tomateiro contendo o locus Ty-1 contra espécies brasileiras de Begomovirus de genoma bipartido

    Directory of Open Access Journals (Sweden)

    Leonardo Silva Boiteux

    2007-03-01

    Full Text Available The number of tomato-infecting begomoviruses has increased in Brazil after the introduction of the polyphagous vector Bemisia tabaci biotype B. The Ty-1 locus, introgressed from Lycopersicon chilense, controls tolerance to species of the monopartite Tomato yellow leaf curl virus (TYLCV complex in Europe and the Middle East. However, little information is available about the Ty-1 effectiveness against species of the bipartite Begomovirus complex occurring in Brazil. Heterozygous (Ty-1/ty-1 and homozygous (ty-1/ty-1 hybrids were evaluated for reaction to Begomovirus isolates under open field conditions in two growing areas in Central Brazil. Test plants were evaluated under natural inoculation with high vector pressure. Evaluation was done using a disease assessment scale (DAS varying from 1= no symptoms to 4= severe symptoms. Systemic infection was evaluated via polymerase chain reaction (PCR using 'universal' Begomovirus primers. In the trial #1, the hybrids (Ty-1/ty-1 and (ty-1/ty-1 had 35% and 95% of plants with symptoms and 75% and 100% of plants with positive PCR, respectively. In the trial #2, only 20% of the Ty-1/ty-1 hybrid plants were symptom-free with both hybrids displaying 100% of plants with positive PCR. This reaction of the Ty-1 hybrid to bipartite Begomovirus species was similar to that reported in Europe and the Middle East to the TYLCV complex with a large number of plants being neither virus-free nor symptom-free. On the other hand, symptom expression of the Ty-1 hybrid was significantly milder than ty-1/ty-1 hybrids in both trials (DAS = 1.35 vs. 2.70 for the trial #1 and DAS = 2.05 vs. 3.95 for the trial #2. Nucleotide sequencing indicated the presence of isolates genetically related to Tomato rugose mosaic virus (ToRMV in the trial #1 and a mixed infection of ToRMV and Tomato yellow vein streak virus in the trial #2. Therefore, the Ty-1 locus seems to control a "tolerance" response to distinct Begomovirus species. Resistance

  3. PMC- FISHs in Hybrids of Tetraploid Cultivated and Diploid Wild Gossypium Species%四倍体栽培棉与二倍体野生棉杂种PMC-FISH研究

    Institute of Scientific and Technical Information of China (English)

    凌键; 王坤波; 邹美娟; 宋国立; 王春英; 彭仁海; 刘方; 黎绍惠; 张香娣; 王玉红

    2009-01-01

    首次将PMC-FISH(花粉母细胞荧光原位杂交)技术应用于四倍体栽培棉与二倍体野生棉杂交所形成的三倍体杂种棉F1中,成功的鉴定了目标染色体中的单价体、双价体、多价体,还发现在非目标染色体上有星状和片段状的杂交信号.在以A组棉基因组DNA作为探针的PMC-FISH中,分别对三倍体杂种棉F1及其母本四倍体栽培棉的减数分裂中期I的染色体构型进行了鉴定.结果显示,四个三倍体杂种棉F1的减数分裂时期染色体的构型分别是:陆地棉(AD)1×雷蒙德氏棉(D5)为1IIIaad + 1IIaa + 4IIad + 7IIdd + 5Ⅰa + 7Ⅰd;海岛棉(AD)2×旱地棉(D4)为1Ⅴaaaad +1IIIadd + 2IIad + 8IIdd + 6Ⅰa + 5Ⅰd;陆地棉(AD)1×澳洲棉(C3)为2IIIadd (adc or acc) + 1IIaa + 9Ⅰa + 4IIcc (dc or dd) + 14Ⅰd (c);陆地棉(AD)1×南岱华棉(C1-n)为:1IIaa + 1IIad (ac)+ 10Ⅰa + 6IIcc (dc or dd) + 13Ⅰd (c).然而,两个四倍体棉染色体的构型都是13IIaa + 13IIdd.上述结果还显示, AD×D的两个杂种组合中,二价体多,单价体少,AD×C的两个杂种组合中,二价体少,单价体多;并且AD×D型杂种中A亚组染色体单体的数目比其在AD×C型杂种中的更少.这说明,与C染色体组相比较,D染色体组与四倍体棉种的亲缘关系更近.同时,我们的结果也证明PMC-FISH技术在分析三倍体杂种棉F1的亲缘关系中起着不可取代的作用.%PMC-FISH (pollen mother cell-fluorescence in situ hybridization) technology was firstly applied to identify probed chromosomes in univalent, bivalent and multivalent, as well as to distinguish star- or fragment-like hybridization signals from non-probed chromosomes in four triploid F1 hybrids produced by cultivated allotetraploid cotton crossed with different diploid cotton species in the genus Gossypium. Using genomic DNA from A genome species as probe, the meiotic chromosome configurations in metaphase Ⅰof four triploid F1 hybrids were identified as 1Ⅲaad + 1Ⅱaa + 4

  4. Behavioral and spermatogenic hybrid male breakdown in Nasonia.

    Science.gov (United States)

    Clark, M E; O'Hara, F P; Chawla, A; Werren, J H

    2010-03-01

    Several reproductive barriers exist within the Nasonia species complex, including allopatry, premating behavioral isolation, postzygotic inviability and Wolbachia-induced cytoplasmic incompatibility. Here we show that hybrid males suffer two additional reproductive disadvantages, an inability to properly court females and decreased sperm production. Hybrid behavioral sterility, characterized by a reduced ability of hybrids to perform necessary courtship behaviors, occurs in hybrids between two species of Nasonia. Hybrid males produced in crosses between N. vitripennis and N. giraulti courted females at a reduced frequency (23-69%), compared with wild-type N. vitripennis and N. giraulti males (>93%). Reduced courtship frequency was not a simple function of inactivity among hybrids. A strong effect of cytoplasmic (mitochondrial) background was also found in N. vitripennis and N. giraulti crosses; F2 hybrids with giraulti cytoplasm showing reduced ability at most stages of courtship. Hybrids produced between a younger species pair, N. giraulti and N. longicornis, were behaviorally fertile. All males possessed motile sperm, but sperm production is greatly reduced in hybrids between the older species pair, N. vitripennis and N. giraulti. This effect on hybrid males, lowered sperm counts rather than nonfunctional sperm, is different from most described cases of hybrid male sterility, and may represent an earlier stage of hybrid sperm breakdown. The results add to previous studies of F2 hybrid inviability and behavioral sterility, and indicate that Wolbachia-induced hybrid incompatibility has arisen early in species divergence, relative to behavioral sterility and spermatogenic infertility.

  5. Understanding the role of the cytoskeleton in wood formation in angiosperm trees: hybrid aspen (Populus tremula x P. tremuloides) as a model species

    Energy Technology Data Exchange (ETDEWEB)

    Chaffey, N.; Barlow, P. [Bristol Univ., Dept. of Agricultural Sciences, Long Ashton, (United Kingdom); Sundberg, B. [Swedish Univ. of Agricultural Sciences, Dept. of Forest Genetics and Plant Physiology, Umea (Sweden)

    2002-03-01

    The involvement of microfilaments (MFs) and microtubules (MTs) in the development of the radial and axial components of secondary wood in hybrid aspen (Populus tremula X P. tremuloides) was studied by indirect immunofluorescent localization techniques in order to elucidate a consensus view of the roles of the cytoskeleton during wood formation in angiosperm trees. Early and late vessel elements, axial parenchyma, normal-wood fibres and contact and isolation cells were included in addition to cambial cells. Microfilaments were found to be rare in cambial cells, but were abundant and axially arranged in their derivatives once cell elongation begun. Microtubules were randomly oriented in ray and fusiform cells of the cambial zone. Ellipses of microfilaments were associated with pit development in fiber cells and isolation ray cells. Rings of localized microtubules and microfilaments were associated with developing inter-vessel bordered pits and vessel-contact ray cell contact pits. Although only microtubules were seen in the periphery of the perforation plate of vessel elements, a prominent meshwork of microfilaments overlaid the perforation plate itself. These observations indicate that there are corresponding subcellular control points whose manipulation could lead to the development of 'designer wood'. However, such development would require a better understanding of the physiological basis for the behaviour of microtubule and microfibre cytoskeletons during wood formation. 44 refs., 6 figs.

  6. Untangling the evolutionary history of a highly polymorphic species: introgressive hybridization and high genetic structure in the desert cichlid fish Herichtys minckleyi.

    Science.gov (United States)

    Magalhaes, Isabel S; Ornelas-Garcıa, Claudia Patricia; Leal-Cardin, Mariana; Ramírez, Tania; Barluenga, Marta

    2015-09-01

    Understanding the origin of biodiversity requires knowledge on the evolutionary processes that drive divergence and speciation, as well as on the processes constraining it. Intraspecific polymorphisms can provide insight into the mechanisms that generate and maintain phenotypic, behavioural and life history diversification, and can help us understand not only the processes that lead to speciation but also the processes that prevent local fixation of morphs. The 'desert cichlid' Herichtys minckleyi is a highly polymorphic species endemic to a biodiversity hotspot in northern Mexico, the Cuatro Ciénegas valley. This species is polymorphic in body shape and trophic apparatus, and eco-morphotypes coexist in small spring-fed lagoons across the valley. We investigated the genetic structure of these polymorphisms and their phylogeographic history by analysing the entire control region of the mitochondrial DNA and 10 nuclear microsatellite markers in several populations from different sites and morphs. We found two very divergent mitochondrial lineages that most likely predate the closing of the valley and are not associated with morphotypes or sites. One of these lineages is also found in the sister species Herichthys cyanoguttatus. Data from neutral microsatellite markers suggest that most lagoons or drainages constitute their own genetic cluster with sympatric eco-morphotypes forming panmictic populations. Alternative mechanisms such as phenotypic plasticity and a few loci controlled traits provide possible explanations for the sympatric coexistence of discrete nonoverlapping eco-morphotypes with apparent lack of barriers to gene flow within multiple lagoons and drainages. © 2015 John Wiley & Sons Ltd.

  7. Arabidopsis hybrid speciation processes.

    Science.gov (United States)

    Schmickl, Roswitha; Koch, Marcus A

    2011-08-23

    The genus Arabidopsis provides a unique opportunity to study fundamental biological questions in plant sciences using the diploid model species Arabidopsis thaliana and Arabidopsis lyrata. However, only a few studies have focused on introgression and hybrid speciation in Arabidopsis, although polyploidy is a common phenomenon within this genus. More recently, there is growing evidence of significant gene flow between the various Arabidopsis species. So far, we know Arabidopsis suecica and Arabidopsis kamchatica as fully stabilized allopolyploid species. Both species evolved during Pleistocene glaciation and deglaciation cycles in Fennoscandinavia and the amphi-Beringian region, respectively. These hybrid studies were conducted either on a phylogeographic scale or reconstructed experimentally in the laboratory. In our study we focus at a regional and population level. Our research area is located in the foothills of the eastern Austrian Alps, where two Arabidopsis species, Arabidopsis arenosa and A. lyrata ssp. petraea, are sympatrically distributed. Our hypothesis of genetic introgression, migration, and adaptation to the changing environment during the Pleistocene has been confirmed: We observed significant, mainly unidirectional gene flow between the two species, which has given rise to the tetraploid A. lyrata. This cytotype was able to escape from the narrow ecological niche occupied by diploid A. lyrata ssp. petraea on limestone outcrops by migrating northward into siliceous areas, leaving behind a trail of genetic differentiation.

  8. Cloning and Expression Pattern of a Gene Encoding a Putative Plastidic ATP/ADP Transporter from Helianthus tuberosus L.

    Institute of Scientific and Technical Information of China (English)

    Kun MENG; Tuan-Jie CHANG; Xiang LIU; Song-Biao CHEN; Yong-Qin WANG; Ai-Jun SUN; Hong-Lin XU; Xiao-Li WEI; Zhen ZHU

    2005-01-01

    Herein, we report the cloning and molecular characterization of a full cDNA encoding a putative plastidic ATP/ADP transporter, designated HtAATP, for Helianthus tuberosus L. The ATP/ADP translocator protein was isolated from the tuber-cDNA library of H. tuberosus for the first time. The predicted HtAATP protein was judged as a plastidic ATP/ADP translocator protein from its high homology at the amino acid sequence level to the two Arabidopsis thaliana plastidic ATP/ADP translocator proteins AATP1 and AATP2 (84.8% and 79.9% identity, respectively). Amino acid sequence analysis of the primary structure of HtAATP revealed that it belonged to the plastidic ATP/ADP transporter family. Hydropathy prediction indicated that HtAATP gene product is a highly hydrophobic membrane protein that contains 10 transmembrane domains to form a spanning topology. Southern blotting analysis showed that the HtAATP gene is a single-copy gene in the H. tuberosus genome. Tissue distribution analysis showed that the HtAATP gene is prominently expressed in sink tissues. A stable expression pattern in tubers at different developmental stages implies an active involvement of HtAATP during carbohydrate formation.

  9. Evaluating the Effects of Municipal Waste and Wastewater on Absorption of Nickel and Cadmium of Helianthus Annuus Plant

    Directory of Open Access Journals (Sweden)

    Amirhossein Ashouri

    2016-01-01

    Full Text Available The present study is an attempt to examine the effects of municipal waste and wastewater on absorption of nickel and cadmium of helianthus annuus plant. In order to determine cadmium and nickel in different organs of the plant in soil with organic fertilizers of municipal waste and municipal sewage sludge, we conducted a split plot study. The study was in form of randomized complete block from 2011 to 2015 under farm conditions. We considered the main factor in five levels of control, 10 and 20 tons of sewage sludge and municipal waste compost per hectare besides the minor factor of yearly treatment during four years. The results showed that using 20 tons of sewage sludge and waste per hectare increased absorbable soil nickel and cadmium up to approximately 220%. Also, the amount of cadmium and nickel in root was about 400% more than the control group. Bacteria found in soil contaminated to heavy metals showed remarkable resistance against higher concentration of these elements. Both bioaccumulation and biosorption techniques indicated high potential to refine aquatic environments. However, the bioaccumulation technique showed better efficiency in lower concentrations and the biosorption revealed better efficiency in higher concentrations of metals.

  10. Leaf surface and histological perturbations of leaves of Phaseolus vulgaris and Helianthus annuus after exposure to simulated acid rain

    Energy Technology Data Exchange (ETDEWEB)

    Evans, L.S. (Manhattan Coll., Bronx, NY); Gmur, N.F.; Da Costa, F.

    1977-08-01

    Initial injury to adaxial leaf surfaces of Phaseolus vulgaris and Helianthus annuus occurred near trichomes and stomata after exposure to simulated sulfate acid rain. Lesion frequency was not correlated with density of either stomata or trichomes but was correlated with degree of leaf expansion. The number of lesions per unit area increased with total leaf area. Results suggest that characteristics of the leaf indumentum such as development of trichomes and guard cells and/or cuticle thickness near these structures may be involved in lesion development. Adaxial epidermal cell collapse was the first event in lesion development. Palisade cells and eventually spongy mesophyll cells collapsed after continued, daily exposure to simulated rain of low pH. Lesion development on Phaseolus vulgaris followed a specific course of events after exposure to simulated rain of known composition, application rate, drop size frequency, drop velocities, and frequency of exposures. These results allow development of further experiments to observe accurately other parameters, such as nutrient inputs and nutrient leaching from foliage, after exposure to simulated sulfate acid rain.

  11. Elimination of natural uranium and {sup 226}Ra from contaminated waters by rhizofiltration using Helianthus annuus L

    Energy Technology Data Exchange (ETDEWEB)

    Vera Tome, F. [Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz (Spain)], E-mail: fvt@unex.es; Blanco Rodriguez, P. [Departamento de Fisica, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz (Spain); Lozano, J.C. [Laboratorio de Radiactividad Ambiental, Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca (Spain)

    2008-04-15

    The elimination of natural uranium and {sup 226}Ra from contaminated waters by rhizofiltration was tested using Helianthus annuus L. (sunflower) seedlings growing in a hydroponic medium. Different experiments were designed to determine the optimum age of the seedlings for the remediation process, and also to study the principal way in which the radionuclides are removed from the solution by the sunflower roots. In every trial a precipitate appeared which contained a major fraction of the natural uranium and {sup 226}Ra. The results indicated that the seedlings themselves induced the formation of this precipitate. When four-week-old seedlings were exposed to contaminated water, a period of only 2 days was sufficient to remove the natural uranium and {sup 226}Ra from the solution: about 50% of the natural uranium and 70% of the {sup 226}Ra were fixed in the roots, and essentially the rest was found in the precipitate, with only very small percentages fixed in the shoots and left in solution.

  12. Aseptic hydroponics to assess rhamnolipid-Cd and rhamnolipid-Zn bioavailability for sunflower (Helianthus annuus): a phytoextraction mechanism study.

    Science.gov (United States)

    Wen, Jia; McLaughlin, Mike J; Stacey, Samuel P; Kirby, Jason K

    2016-11-01

    The availability of cadmium (Cd) and zinc (Zn) to sunflower (Helianthus annuus) was investigated in rhamnolipid- and ethylenediaminetetraacetic acid (EDTA)-buffered solutions in order to evaluate the influence of aqueous speciation of the metals on their uptake by the plant, in relation to predictions of uptake by the free ion activity model (FIAM). Free metal ion activity was estimated using the chemical equilibrium program MINTEQ or measured by Donnan dialysis. The uptake of Cd followed the FIAM for the EDTA-buffered solution at EDTA concentrations below 0.4 μM; for the rhamnolipid-buffered solution, the uptake of both metals in roots was not markedly affected by increasing rhamnolipid concentrations in solution. This suggests rhamnolipid enhanced metal accumulation in plant roots (per unit free metal in solution) possibly through formation and uptake of lipophilic complexes. The addition of normal Ca concentrations (low millimetre range) to the rhamnolipid uptake solutions reduced Cd accumulation in shoots by inhibiting Cd translocation, whereas it significantly increased Zn accumulation in shoots. This study confirms that although rhamnolipid could enhance accumulation of Cd in plants roots at low Ca supply, it is not suitable for Cd phytoextraction in contaminated soil environments where Ca concentrations in soil solution are orders of magnitude greater than those of Cd.

  13. Ammonium improves iron nutrition by decreasing leaf apoplastic pH of sunflower plants (Helianthus annuus L. cv. Frankasol)

    Institute of Scientific and Technical Information of China (English)

    ZOU Chunqin; ZHANG Fusuo

    2003-01-01

    The effect of nitrogen form on pH and concentration of soluble iron (Fe) in leaf apoplast was investigated in hydrophonically grown sunflower plants (Helianthus annuus L. cv. Frankasol), and the mechanism underlying the improved Fe nutrition by ammonium (NH4) supply was also elucidated. Ammonium supply ameliorated Fe nutrition of plants grown without Fe through decreasing apoplastic pH and increasing soluble Fe concentration in apoplastic fluid of young leaves. The soluble Fe concentration in apoplastic fluid and cell sap of young leaves, and xylem exudates of NH4 fed-plants was higher than that of nitrate (NO3) fed-plants, and no typical Fe-deficiency chlorosis in young leaves was observed in NH4 fed plant without Fe supply. The apoplastic pH was 6.15 and 5.94 in young leaves of Fe-deficient plants fed respectively with NO3 and NH4, while in Fe-sufficient plants, the apoplastic pH was 6.43 with NO3, and 5.50 with NH4 supply. In primary leaves, the apoplastic pH was around 6.25 irrespective of nitrogen form and Fe supply. The pH of xylem exudate was 5.72 in Fe-deficient plants fed with NO3 and 5.49 with NH4. Iron nutrition increased the pH of xylem exudate by 0.27 and 0.16 unit under NO3 and NH4 supply respectively.

  14. Anti-Gouty Arthritis and Antihyperuricemia Effects of Sunflower (Helianthus annuus Head Extract in Gouty and Hyperuricemia Animal Models

    Directory of Open Access Journals (Sweden)

    Lanzhou Li

    2017-01-01

    Full Text Available This study was performed to investigate the therapeutic effects and possible mechanisms of sunflower (Helianthus annuus head extract (SHE on gout. First, the components of sunflower head powder and SHE were analyzed systematically. SHE, especially SHEB (extracted with 20% ethanol and 80% double-distilled water, strongly suppressed the swelling of the ankles in rats with acute gout induced by monosodium urate (MSU crystals and reduced the levels of uric acid and xanthine oxidase (XO in mice with hyperuricemia induced by oteracil potassium and yeast extract powder. Hematoxylin and eosin staining indicated that SHEB reduced inflammation cells and increased the joint space in the ankle compared with the control rats with MSU-induced gout. In the rats with acute gout, among 13 detected inflammatory cytokines, SHEB significantly enhanced the serum levels of interleukin-10 and the monocyte chemoattractant protein 1α. In the mice with hyperuricemia, SHEB reduced the levels of glutathione peroxidase, superoxide dismutase, malondialdehyde, and nitrogen monoxide in liver tissues. The potential therapeutic effects of SHE on gout are probably due to the production of anti-inflammatory cytokines and the suppression of XO activity via the modulation of oxidative stress status.

  15. EDTA-Coated Fe3O4 Nanoparticles: a Novel Biocompatible Fertilizer for Improving Agronomic Traits of Sunflower (Helianthus Annuus

    Directory of Open Access Journals (Sweden)

    M. Shahrekizad

    2015-04-01

    Full Text Available In this study, a set of experiments were conducted to investigate the influence of EDTA-grafted iron oxide nanoparticles exposure on agronomic traits of sunflower (Helianthus annuus plants. The experiment was implemented by applying Nano-Fe3O4-EDTA and Fe-EDTA fertilizers applied through spray or soil amendment. A variety of parameters including Aerial organ biomass, Number of leaves, Plant height, Chlorophyll content as well as elemental quantities of the plants were investigated. The results demonstrated considerably dominant effect of Nano-Fe3O4-EDTA fertilizer on many of the studied factors. The dramatically increased Fe content of plants (137% relative to the control by using nano-Fe-EDTA, makes this novel fertilizer a promising candidate to obviate iron deficiency problem in plants. Moreover, it was clearly observed that more pronounced positive effects is obtained through soil amendment than by foliar application of fertilizers and only in some cases such as aerial organ biomasses and Fe content, the foliar treatment has turned out to be more effective.

  16. Cell wall water content has a direct effect on extensibility in growing hypocotyls of sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Evered, Carol; Majevadia, Bhavita; Thompson, David Stuart

    2007-01-01

    It has been proposed that spacing between cellulose microfibrils within plant cell walls may be an important determinant of their mechanical properties. A consequence of this hypothesis is that the water content of cell walls may alter their extensibility and that low water potentials may directly reduce growth rates by reducing cell wall spacing. This paper describes a number of experiments in which the water potential of frozen and thawed growing hypocotyls of sunflower (Helianthus annuus L.) were altered using solutions of high molecular weight polyethylene glycol (PEG) or Dextran while their extension under constant stress was monitored using a creep extensiometer (frozen and thawed tissue was used to avoid confounding effects of turgor or active responses to the treatments). Clear reductions in extensibility were observed using both PEG and Dextran, with effects observed in hypocotyl segments treated with PEG 35 000 solutions with osmotic pressures of > or =0.21 MPa suggesting that the relatively mild stresses required to reduce water potentials of plants in vivo by 0.21 MPa may be sufficient to reduce growth rates via a direct effect on wall extensibility. It is noted, therefore, that the water binding capacity of plant cell walls may be of ecophysiological importance. Measurements of cell walls of sunflower hypocotyls using scanning electron microscopy confirmed that treatment of hypocotyls with PEG solutions reduced wall thickness, supporting the hypothesis that the spatial constraint of movement of cellulose microfibrils affects the mechanical properties of the cell wall.

  17. Detection of herbicide effects on pigment composition and PSII photochemistry in Helianthus annuus by Raman spectroscopy and chlorophyll a fluorescence.

    Science.gov (United States)

    Vítek, Petr; Novotná, Kateřina; Hodaňová, Petra; Rapantová, Barbora; Klem, Karel

    2017-01-01

    The effects of herbicides from three mode-of-action groups - inhibitors of protoporphyrinogen oxidase (carfentrazone-ethyl), inhibitors of carotenoid biosynthesis (mesotrione, clomazone, and diflufenican), and inhibitors of acetolactate synthase (amidosulfuron) - were studied in sunflower plants (Helianthus annuus). Raman spectroscopy, chlorophyll fluorescence (ChlF) imaging, and UV screening of ChlF were combined to evaluate changes in pigment composition, photosystem II (PSII) photochemistry, and non-photochemical quenching in plant leaves 6d after herbicide application. The Raman signals of phenolic compounds, carotenoids, and chlorophyll were evaluated and differences in their intensity ratios were observed. Strongly augmented relative content of phenolic compounds was observed in the case of amidosulfuron-treated plants, with a simultaneous decrease in the chlorophyll/carotenoid intensity ratio. The results were confirmed by in vivo measurement of flavonols using UV screening of ChlF. Herbicides from the group of carotenoid biosynthesis inhibitors significantly decreased both the maximum quantum efficiency of PSII and non-photochemical quenching as determined by ChlF. Resonance Raman imaging (mapping) data with high resolution (150,000-200,000 spectra) are presented, showing the distribution of carotenoids in H. annuus leaves treated by two of the herbicides acting as inhibitors of carotenoid biosynthesis (clomazone or diflufenican). Clear signs were observed that the treatment induced carotenoid depletion within sunflower leaves. The depletion spatial pattern registered differed depending on the type of herbicide applied.

  18. Detection of herbicide effects on pigment composition and PSII photochemistry in Helianthus annuus by Raman spectroscopy and chlorophyll a fluorescence

    Science.gov (United States)

    Vítek, Petr; Novotná, Kateřina; Hodaňová, Petra; Rapantová, Barbora; Klem, Karel

    2017-01-01

    The effects of herbicides from three mode-of-action groups - inhibitors of protoporphyrinogen oxidase (carfentrazone-ethyl), inhibitors of carotenoid biosynthesis (mesotrione, clomazone, and diflufenican), and inhibitors of acetolactate synthase (amidosulfuron) - were studied in sunflower plants (Helianthus annuus). Raman spectroscopy, chlorophyll fluorescence (ChlF) imaging, and UV screening of ChlF were combined to evaluate changes in pigment composition, photosystem II (PSII) photochemistry, and non-photochemical quenching in plant leaves 6 d after herbicide application. The Raman signals of phenolic compounds, carotenoids, and chlorophyll were evaluated and differences in their intensity ratios were observed. Strongly augmented relative content of phenolic compounds was observed in the case of amidosulfuron-treated plants, with a simultaneous decrease in the chlorophyll/carotenoid intensity ratio. The results were confirmed by in vivo measurement of flavonols using UV screening of ChlF. Herbicides from the group of carotenoid biosynthesis inhibitors significantly decreased both the maximum quantum efficiency of PSII and non-photochemical quenching as determined by ChlF. Resonance Raman imaging (mapping) data with high resolution (150,000-200,000 spectra) are presented, showing the distribution of carotenoids in H. annuus leaves treated by two of the herbicides acting as inhibitors of carotenoid biosynthesis (clomazone or diflufenican). Clear signs were observed that the treatment induced carotenoid depletion within sunflower leaves. The depletion spatial pattern registered differed depending on the type of herbicide applied.

  19. Translatome profiling in dormant and nondormant sunflower (Helianthus annuus) seeds highlights post-transcriptional regulation of germination.

    Science.gov (United States)

    Layat, Elodie; Leymarie, Juliette; El-Maarouf-Bouteau, Hayat; Caius, José; Langlade, Nicolas; Bailly, Christophe

    2014-12-01

    Seed dormancy, which blocks germination in apparently favourable conditions, is a key regulatory control point of plant population establishment. As germination requires de novo translation, its regulation by dormancy is likely to be related to the association of individual transcripts to polysomes. Here, the polysome-associated mRNAs, that is, the translatome, were fractionated and characterized with microarrays in dormant and nondormant sunflower (Helianthus annuus) embryos during their imbibition at 10°C, a temperature preventing germination of dormant embryos. Profiling of mRNAs in polysomal complexes revealed that the translatome differs between germinating and nongerminating embryos. Association of transcripts with polysomes reached a maximum after 15 h of imbibition; at this time-point 194 polysome-associated transcripts were specifically found in nondormant embryos and 47 in dormant embryos only. The proteins corresponding to the polysomal mRNAs in nondormant embryos appeared to be very pertinent for germination and were involved mainly in transport, regulation of transcription or cell wall modifications. This work demonstrates that seed germination results from a timely regulated and selective recruitment of mRNAs to polysomes, thus opening novel fields of investigation for the understanding of this developmental process. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  20. Growth, Cadmium and Zinc Accumulation of Ornamental Sunflower (Helianthus annuus L.) in Contaminated Soil with Different Amendments

    Institute of Scientific and Technical Information of China (English)

    HAO Xiu-Zhen; ZHOU Dong-Mei; LI Dan-Dan; JIANG Ping

    2012-01-01

    Use of ornamental plants for phytoremediation of metal-contaminated soil is a new option.A pot experiment was carried out to assess the effect of application of amendments,i.e.,swine manure,salicylic acid (SA) and potassium chloride (KCl),on the growth,uptake and translocation of cadmium (Cd) and zinc (Zn) of ornamental sunflower (Helianthus annuus L.) grown on a contaminated soil.The three amendments increased sunflower height,flower diameter,and biomass.Manure significantly decreased Cd and Zn concentrations in sunflower,and thus decreased the bioaccumulation coefficient (BCF) of Cd and Zn.However,using of KCI markedly increased Cd concentrations in sunflower and the BCF of Cd.Additionally,both swine manure and KCl application increased Cd and Zn translocation from root to aboveground part.Swine manure and salicylic acid reduced the Cd/Zn ratios in flower of sunflower,while KCl significantly increased the Cd/Zn ratios.Correlation analysis demonstrated that the Cd/Zn ratio in the root of sunflower was affected by K/Na ratio in root and soil available potassium (K) concentration.Ornamental sunflower could be grown as an alternative plant in the Cd- and Zn-contaminated soil with KCl application to get the balance between environmental and economic interests.

  1. Effect on germination and early growth characteristics in sunflower (Helianthus annuus) seeds exposed to static magnetic field.

    Science.gov (United States)

    Vashisth, Ananta; Nagarajan, Shantha

    2010-01-15

    Seeds of sunflower (Helianthus annuus) were exposed in batches to static magnetic fields of strength from 0 to 250mT in steps of 50mT for 1-4h in steps of 1h. Treatment of sunflower seeds in these magnetic fields increased the speed of germination, seedling length and seedling dry weight under laboratory germination tests. Of the various treatments, 50 and 200mT for 2h yielded the peak performance. Exposure of seeds to magnetic fields improved seed coat membrane integrity and reduced the cellular leakage and electrical conductivity. Treated seeds planted in soil resulted in statistically higher seedling dry weight, root length, root surface area and root volume in 1-month-old seedlings. In germinating seeds, enzyme activities of alpha-amylase, dehydrogenase and protease were significantly higher in treated seeds in contrast to controls. The higher enzyme activity in magnetic-field-treated sunflower seeds could be triggering the fast germination and early vigor of seedlings.

  2. Cloning and characterization of a cDNA encoding type 1 diacylglycerol acyltransferase from sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Sun, Li; Ouyang, Chao; Kou, Shanglong; Wang, Shenghua; Yao, Yunyi; Peng, Tong; Xu, Ying; Tang, Lin; Chen, Fang

    2011-01-01

    A full-length cDNA encoding a putative diacylglycerol acyltransferase (DGAT; EC 2.3.1.20) was obtained from sunflower (Helianthus annuus L.) seeds. The 1524-bp open reading frame of this cDNA, designated as HaDGAT1, encodes a protein of 507 amino acids with a molecular mass of 58.5 kDa showing high homology to DGAT1 enzymes of other plants. The protein characters, such as a predicted structure with a long N-terminal hydrophilic domain followed by 9 transmembrane domains, acyl-CoA-binding signature, diacylglycerol (DAG)-binding and putative endoplasmic reticulum retrieval motifs (ER-DIR), also indicated that HaDGAT belongs to the DGAT1 family. HaDGAT1 is expressed in all plant tissues especially in developing seeds. Expression of recombinant HaDGAT1 in yeast showed an 1.76-fold increase of total fatty acids, especially unsaturated fatty acids such as palmitoleic acid (enhanced by 86.6%) and oleic acid (enhanced by 81.6%).

  3. The Comparison of Effects of Gamma Radiation of Crude Oil Yield on Some Sunflower (Helianthus Annuus Seeds

    Directory of Open Access Journals (Sweden)

    Havser ERTEM VAİZOĞULLAR

    2015-01-01

    Full Text Available This study compares the effects of different doses gamma radiation on crude oil yield and moisture of different six variety sunflower (Helianthus annuus L. seeds. As materials, sunflower variety Ege-2001, Turay, AS-508, Tunca, TR-3080 and Tarsan-1018 seeds were used and irradiated with doses of 0 (control, 100, 200, 300, 400 and 500 Gy gamma radiation. Irradiation was performed in a cesium (Ce137 Gammacell 3000 Elan source, dose rate about 9.75 Gy/min (2900 Ci in the Pamukkale University Faculty of Medicine in the department of the radiological. Moisture amount of seeds were also measured by AOCS standarts. Extraction of the seeds was done with soxhlet apparatus using petroleum ether by hot continuous extraction for 6 hours.  It was found that the highest moisture rate in 100 Gy for all seeds variety. The moisture rate ranged between 3.00 and 9.68% in TR-3080 and Ege-2001, respectively. According to the our results, seed moisture content was affected by gamma radiation in a significant negative one-way. The significant reduction in seed moisture content (9.68% began at 100 Gy of gamma rays and continued to decline to up to 4.04% at 500 Gy. The crude oil yield showed not a important increase in 100 and 200 Gy doses. The result showed that the highest crude oil yield was also obtained from 400 Gy and 33.49% in Ege-2001 seeds.

  4. Rhizofiltration using sunflower (Helianthus annuus L.) and bean (Phaseolus vulgaris L. var. vulgaris) to remediate uranium contaminated groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Minhee, E-mail: heelee@pknu.ac.kr [Department of Environmental Geosciences, Pukyong National University, 599-1 Daeyondong, Namgu, Busan 608-737 (Korea, Republic of); Yang, Minjune [Department of Environmental Geosciences, Pukyong National University, 599-1 Daeyondong, Namgu, Busan 608-737 (Korea, Republic of)

    2010-01-15

    The uranium removal efficiencies of rhizofiltration in the remediation of groundwater were investigated in lab-scale experiments. Sunflower (Helianthus annuus L.) and bean (Phaseolus vulgaris L. var. vulgaris) were cultivated and an artificially uranium contaminated solution and three genuine groundwater samples were used in the experiments. More than 80% of the initial uranium in solution and genuine groundwater, respectively, was removed within 24 h by using sunflower and the residual uranium concentration of the treated water was lower than 30 {mu}g/L (USEPA drinking water limit). For bean, the uranium removal efficiency of the rhizofiltration was roughly 60-80%. The maximum uranium removal via rhizofiltration for the two plant cultivars occurred at pH 3-5 of solution and their uranium removal efficiencies exceeded 90%. The lab-scale continuous rhizofiltration clean-up system delivered over 99% uranium removal efficiency, and the results of SEM and EDS analyses indicated that most uranium accumulated in the roots of plants. The present results suggested that the uranium removal capacity of two plants evaluated in the clean-up system was about 25 mg/kg of wet plant mass. Notably, the removal capacity of the root parts only was more than 500 mg/kg.

  5. Cloning, biochemical characterization and expression of a sunflower (Helianthus annuus L.) hexokinase associated with seed storage compounds accumulation.

    Science.gov (United States)

    Troncoso-Ponce, M A; Rivoal, J; Dorion, S; Moisan, M-C; Garcés, R; Martínez-Force, E

    2011-03-01

    A full-length hexokinase cDNA, HaHXK1, was cloned and characterized from Helianthus annuus L. developing seeds. Based on its sequence and phylogenetic relationships, HaHXK1 is a membrane-associated (type-B) hexokinase. The predicted structural model resembles known hexokinase structures, folding into two domains of unequal size: a large and a small one separated by a deep cleft containing the residues involved in the enzyme active site. A truncated version, without the 24 N-terminal residues, was heterologously expressed in Escherichia coli, purified to electrophoretic homogeneity using immobilized metal ion affinity chromatography and biochemically characterized. The purified enzyme behaved as a monomer on size exclusion chromatography and had a specific activity of 19.3 μmol/min/mg protein, the highest specific activity ever reported for a plant hexokinase. The enzyme had higher affinity for glucose and mannose relative to fructose, but the enzymatic efficiency was higher with glucose. Recombinant HaHXK1 was inhibited by ADP and was insensitive either to glucose-6-phosphate or to trehalose-6-phosphate. Its expression profile showed higher levels in heterotrophic tissues, developing seeds and roots, than in photosynthetic ones. A time course of HXK activity and expression in seeds showed that the highest HXK levels are found at the early stages of reserve compounds, lipids and proteins accumulation.

  6. Cloning, heterologous expression and biochemical characterization of plastidial sn-glycerol-3-phosphate acyltransferase from Helianthus annuus.

    Science.gov (United States)

    Payá-Milans, Miriam; Venegas-Calerón, Mónica; Salas, Joaquín J; Garcés, Rafael; Martínez-Force, Enrique

    2015-03-01

    The acyl-[acyl carrier protein]:sn-1-glycerol-3-phosphate acyltransferase (GPAT; E.C. 2.3.1.15) catalyzes the first step of glycerolipid assembly within the stroma of the chloroplast. In the present study, the sunflower (Helianthus annuus, L.) stromal GPAT was cloned, sequenced and characterized. We identified a single ORF of 1344base pairs that encoded a GPAT sharing strong sequence homology with the plastidial GPAT from Arabidopsis thaliana (ATS1, At1g32200). Gene expression studies showed that the highest transcript levels occurred in green tissues in which chloroplasts are abundant. The corresponding mature protein was heterologously overexpressed in Escherichia coli for purification and biochemical characterization. In vitro assays using radiolabelled acyl-ACPs and glycerol-3-phosphate as substrates revealed a strong preference for oleic versus palmitic acid, and weak activity towards stearic acid. The positional fatty acid composition of relevant chloroplast phospholipids from sunflower leaves did not reflect the in vitro GPAT specificity, suggesting a more complex scenario with mixed substrates at different concentrations, competition with other acyl-ACP consuming enzymatic reactions, etc. In summary, this study has confirmed the affinity of this enzyme which would partly explain the resistance to cold temperatures observed in sunflower plants.

  7. Enhanced Pb Absorption by Hordeum vulgare L. and Helianthus annuus L. Plants Inoculated with an Arbuscular Mycorrhizal Fungi Consortium.

    Science.gov (United States)

    Arias, Milton Senen Barcos; Peña-Cabriales, Juan José; Alarcón, Alejandro; Maldonado Vega, María

    2015-01-01

    The effect of an arbuscular mycorrhizal fungi (AMF) consortium conformed by (Glomus intraradices, Glomus albidum, Glomus diaphanum, and Glomus claroideum) on plant growth and absorption of Pb, Fe, Na, Ca, and (32)P in barley (Hordeum vulgare L.) and sunflower (Helianthus annuus L.) plants was evaluated. AMF-plants and controls were grown in a substrate amended with powdered Pb slag at proportions of 0, 10, 20, and 30% v/v equivalent to total Pb contents of 117; 5,337; 13,659, and 19,913 mg Pb kg(-1) substrate, respectively. Mycorrhizal root colonization values were 70, 94, 98, and 90%, for barley and 91, 97, 95, and 97%, for sunflower. AMF inoculum had positive repercussions on plant development of both crops. Mycorrhizal barley absorbed more Pb (40.4 mg Pb kg(-1)) shoot dry weight than non-colonized controls (26.5 mg Pb kg(-1)) when treated with a high Pb slag dosage. This increase was higher in roots than shoots (650.0 and 511.5 mg Pb kg(-1) root dry weight, respectively). A similar pattern was found in sunflower. Plants with AMF absorbed equal or lower amounts of Fe, Na and Ca than controls. H. vulgare absorbed more total P (1.0%) than H. annuus (0.9%). The arbuscular mycorrizal consortium enhanced Pb extraction by plants.

  8. Molecular cloning and biochemical characterization of three phosphoglycerate kinase isoforms from developing sunflower (Helianthus annuus L.) seeds.

    Science.gov (United States)

    Troncoso-Ponce, M A; Rivoal, J; Venegas-Calerón, M; Dorion, S; Sánchez, R; Cejudo, F J; Garcés, R; Martínez-Force, E

    2012-07-01

    Three cDNAs encoding different phosphoglycerate kinase (PGK, EC 2.7.2.3) isoforms, two cytosolic (HacPGK1 and HacPGK2) and one plastidic (HapPGK), were cloned and characterized from developing sunflower (Helianthus annuus L.) seeds. The expression profiles of these genes showed differences in heterotrophic tissues, such as developing seeds and roots, where HacPGK1 was predominant, while HapPGK was highly expressed in photosynthetic tissues. The cDNAs were expressed in Escherichia coli, and the corresponding proteins purified to electrophoretic homogeneity, using immobilized metal ion affinity chromatography, and biochemically characterized. Despite the high level of identity between sequences, the HacPGK1 isoform showed strong differences in terms of specific activity, temperature stability and pH sensitivity in comparison to HacPGK2 and HapPGK. A polyclonal immune serum was raised against the purified HacPGK1 isoform, which showed cross-immunoreactivity with the other PGK isoforms. This serum allowed the localization of high expression levels of PGK isozymes in embryo tissues.

  9. Rhizofiltration using sunflower (Helianthus annuus L.) and bean (Phaseolus vulgaris L. var. vulgaris) to remediate uranium contaminated groundwater.

    Science.gov (United States)

    Lee, Minhee; Yang, Minjune

    2010-01-15

    The uranium removal efficiencies of rhizofiltration in the remediation of groundwater were investigated in lab-scale experiments. Sunflower (Helianthus annuus L.) and bean (Phaseolus vulgaris L. var. vulgaris) were cultivated and an artificially uranium contaminated solution and three genuine groundwater samples were used in the experiments. More than 80% of the initial uranium in solution and genuine groundwater, respectively, was removed within 24h by using sunflower and the residual uranium concentration of the treated water was lower than 30 microg/L (USEPA drinking water limit). For bean, the uranium removal efficiency of the rhizofiltration was roughly 60-80%. The maximum uranium removal via rhizofiltration for the two plant cultivars occurred at pH 3-5 of solution and their uranium removal efficiencies exceeded 90%. The lab-scale continuous rhizofiltration clean-up system delivered over 99% uranium removal efficiency, and the results of SEM and EDS analyses indicated that most uranium accumulated in the roots of plants. The present results suggested that the uranium removal capacity of two plants evaluated in the clean-up system was about 25mg/kg of wet plant mass. Notably, the removal capacity of the root parts only was more than 500 mg/kg.

  10. A study on correlation and path analysis for seed yield and yield components in sunflower [Helianthus annuus (L.

    Directory of Open Access Journals (Sweden)

    M.M.Pandya, P.B.Patel, A.V. Narwade

    2015-06-01

    Full Text Available Correlation and path coefficient analysis was carried out in 40 genotypes of sunflower [Helianthus annuus (L.]. Association analysis between seed yield per plant and other 14 characters revealed that seed yield per plant showed highly significant and positive correlation with head diameter, number of seeds per capitula, number of filled seeds per capitula and 100 seed weight at both genotypic and phenotypic levels. These seed yield per plant also possessed positive association with days to maturity, stem diameter, number of leaves per plant, leaf area at flowering, plant height, oil content and vacant inner diameter. The characters days to 50 per cent flowering, days to initiation of flower and number of unfilled seeds per capitula exhibited negative correlation with seed yield per plant. Path analysis indicated that days to 50 per cent flowering had highest positive direct effect on seed yield per plant followed by number of leaves per plant. The character days to initiation of flower exhibited high negative direct effects.

  11. Characterization and partial purification of acyl-CoA:glycerol 3-phosphate acyltransferase from sunflower (Helianthus annuus L.) developing seeds.

    Science.gov (United States)

    Ruiz-López, Noemí; Garcés, Rafael; Harwood, John L; Martínez-Force, Enrique

    2010-01-01

    The glycerol 3-phosphate acyltransferase (GPAT, EC 2.3.1.15) from sunflower (Helianthus annuus L.) microsomes has been characterised and partially purified. The in vitro determination of activity was optimized, and the maximum value for GPAT activity identified between 15 and 20 days after flowering. The apparent Michaelis-Menten K(m) for the glycerol 3-phosphate was 354 muM. The preferred substrates were palmitoyl-CoA = linoleoyl-CoA > oleoyl-CoA with the lowest activity using stearoyl-CoA. High solubilisation was achieved using 0.75% Tween80 and the solubilised GPAT was partially purified by ion-exchange chromatography using a Hi-Trap DEAE FF column, followed by gel filtration chromatography using a Superose 12 HR column. The fraction containing the GPAT activity was analysed by SDS-PAGE and contained a major band of 60.1 kDa. Finally, evidence is provided which shows the role of GPAT in the asymmetrical distribution, between positions sn-1 and sn-3, of saturated fatty acids in highly saturated sunflower triacylglycerols. This work provides background information on the sunflower endoplasmic reticulum GPAT which may prove valuable for future modification of oil deposition in this important crop.

  12. Influence of nitrogen fertilization on diazotrophic communities in the rhizosphere of the Jerusalem artichoke (Helianthus tuberosus L.).

    Science.gov (United States)

    Meng, Xianfa; Wang, Lin; Long, Xiaohua; Liu, Zhaopu; Zhang, Zhenhua; Zed, Rengel

    2012-06-01

    Diazotrophs in the soil may be influenced by plant factors as well as nitrogen (N) fertilization. In this study, we investigated potential diazotrophic communities in the rhizosphere of the Jerusalem artichoke (Helianthus tuberosus L.) supplied with differing amounts of N. The community structure of N(2)-fixing bacteria was profiled using the length heterogeneity polymerase chain reaction (LH-PCR) and terminal restriction fragment length polymorphism (T-RFLP) based on a variation in the nifH gene. Higher numbers of diazotrophs were detected by T-RFLP compared to LH-PCR. The lowest number of N(2)-fixing bacteria was observed in the rhizosphere soil with high N fertilization. T-RFLP was a better method than LH-PCR for profiling microbial diversity of diazotrophs using multidimensional scaling (MDS) and analysis of similarity (ANOSIM) of fingerprints as well as diversity measures. The supply of N fertilizer appeared to negatively influence the abundance of diazotrophs in the rhizophere of the Jerusalem artichoke.

  13. The Exploration of Planting Structural Adjustment in Cotton Fields-Take Helianthus annuus Linn. as a Case%湖南棉田种植结构调整探讨--以油葵为例

    Institute of Scientific and Technical Information of China (English)

    匡政成; 陈浩东; 李玉军; 程泽新; 谌兵银; 李育强; 肖才升

    2016-01-01

    In recent years, the prices for cotton decline by a small margin, with which national cotton industry policy is adjusted and the agriculture market is depressed. It is important to ifnd alternative planting crops in non dominant area of cotton production. The analysis of market demand found thatHelianthus annuus Linn is the best replace planting crops in non dominant area of cotton production. To be more important, the planting ofHelianthus annuus Linn have a greater economic beneift than others. Therefore, we can guide peasant plant cotton orHelianthus annuus Linn scientiifcally on the premise that the custom of Brassica campestris-Helianthus annuus Linn or Helianthus annuus Linn-Cotton planting.%近年来,随着国家棉花产业政策调整和粮农市场的不景气,长江流域的棉花种植效益出现一定幅度的下滑,棉花生产非优势区寻找替代种植作物势在必行。通过对湖南气候特征及市场需求分析,发现油葵(Helianthus annuus Linn.)是目前湖南棉田替代种植作物的较佳选择之一;建议在保证农民“棉花-油菜”或“油葵-油菜”种植习惯的前提下,可参考市场需求,科学指导农户种植“棉花”或“油葵”,保证农民收益。

  14. Comprehensive phylogenetic analysis of all species of swordtails and platies (Pisces: Genus Xiphophorus uncovers a hybrid origin of a swordtail fish, Xiphophorus monticolus, and demonstrates that the sexually selected sword originated in the ancestral lineage of the genus, but was lost again secondarily

    Directory of Open Access Journals (Sweden)

    Kang Ji Hyoun

    2013-01-01

    Full Text Available Abstract Background Males in some species of the genus Xiphophorus, small freshwater fishes from Meso-America, have an extended caudal fin, or sword – hence their common name “swordtails”. Longer swords are preferred by females from both sworded and – surprisingly also, non-sworded (platyfish species that belong to the same genus. Swordtails have been studied widely as models in research on sexual selection. Specifically, the pre-existing bias hypothesis was interpreted to best explain the observed bias of females in presumed ancestral lineages of swordless species that show a preference for assumed derived males with swords over their conspecific swordless males. However, many of the phylogenetic relationships within this genus still remained unresolved. Here we construct a comprehensive molecular phylogeny of all 26 known Xiphophorus species, including the four recently described species (X. kallmani, X. mayae, X. mixei and X. monticolus. We use two mitochondrial and six new nuclear markers in an effort to increase the understanding of the evolutionary relationships among the species in this genus. Based on the phylogeny, the evolutionary history and character state evolution of the sword was reconstructed and found to have originated in the common ancestral lineage of the genus Xiphophorus and that it was lost again secondarily. Results We estimated the evolutionary relationships among all known species of the genus Xiphophorus based on the largest set of DNA markers so far. The phylogeny indicates that one of the newly described swordtail species, Xiphophorus monticolus, is likely to have arisen through hybridization since it is placed with the southern platyfish in the mitochondrial phylogeny, but with the southern swordtails in the nuclear phylogeny. Such discordance between these two types of markers is a strong indication for a hybrid origin. Additionally, by using a maximum likelihood approach the possession of the sexually

  15. Comprehensive phylogenetic analysis of all species of swordtails and platies (Pisces: Genus Xiphophorus) uncovers a hybrid origin of a swordtail fish, Xiphophorus monticolus, and demonstrates that the sexually selected sword originated in the ancestral lineage of the genus, but was lost again secondarily.

    Science.gov (United States)

    Kang, Ji Hyoun; Schartl, Manfred; Walter, Ronald B; Meyer, Axel

    2013-01-29

    Males in some species of the genus Xiphophorus, small freshwater fishes from Meso-America, have an extended caudal fin, or sword - hence their common name "swordtails". Longer swords are preferred by females from both sworded and - surprisingly also, non-sworded (platyfish) species that belong to the same genus. Swordtails have been studied widely as models in research on sexual selection. Specifically, the pre-existing bias hypothesis was interpreted to best explain the observed bias of females in presumed ancestral lineages of swordless species that show a preference for assumed derived males with swords over their conspecific swordless males. However, many of the phylogenetic relationships within this genus still remained unresolved. Here we construct a comprehensive molecular phylogeny of all 26 known Xiphophorus species, including the four recently described species (X. kallmani, X. mayae, X. mixei and X. monticolus). We use two mitochondrial and six new nuclear markers in an effort to increase the understanding of the evolutionary relationships among the species in this genus. Based on the phylogeny, the evolutionary history and character state evolution of the sword was reconstructed and found to have originated in the common ancestral lineage of the genus Xiphophorus and that it was lost again secondarily. We estimated the evolutionary relationships among all known species of the genus Xiphophorus based on the largest set of DNA markers so far. The phylogeny indicates that one of the newly described swordtail species, Xiphophorus monticolus, is likely to have arisen through hybridization since it is placed with the southern platyfish in the mitochondrial phylogeny, but with the southern swordtails in the nuclear phylogeny. Such discordance between these two types of markers is a strong indication for a hybrid origin. Additionally, by using a maximum likelihood approach the possession of the sexually selected sword trait is shown to be the most likely

  16. Disease Tolerance in Helianthus petiolaris: A Genetic Resource for Sunflower Breeding

    National Research Council Canada - National Science Library

    Gutierrez, Agustina; Cantamutto, Miguel; Poverene, Monica

    2012-01-01

    .... Controlled crosses of this species with sunflower demonstrated that H. petiolaris constitutes a valuable genetic variability source for sunflower breeding to improve tolerance to rust (Puccinia helianthi), white rust (Albugo tragopogonis...

  17. Ecogeography and utility to plant breeding of the crop wild relatives of sunflower (Helianthus annuus L.)

    Science.gov (United States)

    Crop wild relatives (CWR) are a rich source of genetic diversity for crop improvement. Combining ecogeographic and phylogenetic techniques can inform both conservation and breeding. Geographic occurrence, bioclimatic, and biophysical data were used to predict species distributions, range overlap and...

  18. Ecogeography and utility to plant breeding of the crop wild relatives of sunflower (Helianthus annuus L.)

    NARCIS (Netherlands)

    Kantar, M.B.; Sosa, C.C.; Khoury, C.K.; Castaneda-Alvarez, N.P.; Achicanoy, H.A.; Bernau, V.; Kane, N.C.; Marek, L.; Seiler, G.; Rieseberg, L.H.

    2015-01-01

    Crop wild relatives (CWR) are a rich source of genetic diversity for crop improvement. Combining ecogeographic and phylogenetic techniques can inform both conservation and breeding. Geographic occurrence, bioclimatic, and biophysical data were used to predict species distributions, range overlap and

  19. Hybrid origins of cultivated potatoes.

    Science.gov (United States)

    Rodríguez, Flor; Ghislain, Marc; Clausen, Andrea M; Jansky, Shelley H; Spooner, David M

    2010-10-01

    Solanum section Petota is taxonomically difficult, partly because of interspecific hybridization at both the diploid and polyploid levels. The taxonomy of cultivated potatoes is particularly controversial. Using DNA sequence data of the waxy gene, we here infer relationships among the four species of cultivated potatoes accepted in the latest taxonomic treatment (S. ajanhuiri, S. curtilobum, S. juzepczukii and S. tuberosum, the latter divided into the Andigenum and Chilotanum Cultivar Groups). The data support prior ideas of hybrid origins of S. ajanhuiri from the S. tuberosum Andigenum Group (2x = S. stenotomum) × S. megistacrolobum; S. juzepczukii from the S. tuberosum Andigenum Group (2x = S. stenotomum) × S. acaule; and S. curtilobum from the S. tuberosum Andigenum Group (4x = S. tuberosum subsp. andigenum) × S. juzepczukii. For the tetraploid cultivar-groups of S. tuberosum, hybrid origins are suggested entirely within much more closely related species, except for two of three examined accessions of the S. tuberosum Chilotanum Group that appear to have hybridized with the wild species S. maglia. Hybrid origins of the crop/weed species S. sucrense are more difficult to support and S. vernei is not supported as a wild species progenitor of the S. tuberosum Andigenum Group.

  20. Hybrid origin of Audubon's warbler.

    Science.gov (United States)

    Brelsford, Alan; Milá, Borja; Irwin, Darren E

    2011-06-01

    Several animal species have recently been shown to have hybrid origins, but no avian examples have been documented with molecular evidence. We investigate whether the Audubon's warbler (Dendroica auduboni), one of four visually distinct species in the yellow-rumped warbler complex, has originated through hybridization between two other species in this group, the myrtle warbler (D. coronata) and black-fronted warbler (D. nigrifrons). Analysis of nuclear amplified fragment length polymorphism (AFLP) and sequence markers shows that Audubon's warblers are genetically intermediate and carry a mixture of alleles otherwise found only in one or the other of their putative parental species. Audubon's warblers also carry two deeply divergent mitochondrial DNA lineages, each shared with only one putative parental form. Broad clines between Audubon's and black-fronted warblers in AFLP markers call into question the validity of these two forms as full species; nevertheless, our results suggest that the Audubon's warbler probably originated through hybridization between two long-diverged species. It is likely that more cases of avian species of hybrid origin will be revealed by surveys of variation in nuclear DNA and other traits. © 2011 Blackwell Publishing Ltd.

  1. Hybrid Metaheuristics

    CERN Document Server

    2013-01-01

    The main goal of this book is to provide a state of the art of hybrid metaheuristics. The book provides a complete background that enables readers to design and implement hybrid metaheuristics to solve complex optimization problems (continuous/discrete, mono-objective/multi-objective, optimization under uncertainty) in a diverse range of application domains. Readers learn to solve large scale problems quickly and efficiently combining metaheuristics with complementary metaheuristics, mathematical programming, constraint programming and machine learning. Numerous real-world examples of problems and solutions demonstrate how hybrid metaheuristics are applied in such fields as networks, logistics and transportation, bio-medical, engineering design, scheduling.

  2. Identification of Treponema pedis as the predominant Treponema species in porcine skin ulcers by fluorescence in situ hybridization and high-throughput sequencing

    DEFF Research Database (Denmark)

    Karlsson, Frida; Schou, Kirstine Klitgaard; Jensen, Tim Kåre

    2014-01-01

    Skin lesions often seen in pig production are of great animal welfare concern. To study the potential role of Treponema bacteria in porcine skin ulcers, we investigated the presence and distribution of these organisms in decubital shoulder ulcers (n=51) and ear necroses (n=54) by fluorescence...... probes targeting 16S rRNA were used, specific for domain bacterium, Treponema spp. and species T. pedis. Screening showed that two cases each of facial and other ulcers, 35 (69%) of shoulder ulcers and 32 (59%) of ear necroses were positive for Treponema spp. T. pedis was the unequivocally, predominant...

  3. Ion-atom hybrid systems

    CERN Document Server

    Willitsch, Stefan

    2014-01-01

    The study of interactions between simultaneously trapped cold ions and atoms has emerged as a new research direction in recent years. The development of ion-atom hybrid experiments has paved the way for investigating elastic, inelastic and reactive collisions between these species at very low temperatures, for exploring new cooling mechanisms of ions by atoms and for implementing new hybrid quantum systems. The present lecture reviews experimental methods, recent results and upcoming developments in this emerging field.

  4. Hybrid codes: Methods and applications

    Energy Technology Data Exchange (ETDEWEB)

    Winske, D. (Los Alamos National Lab., NM (USA)); Omidi, N. (California Univ., San Diego, La Jolla, CA (USA))

    1991-01-01

    In this chapter we discuss hybrid'' algorithms used in the study of low frequency electromagnetic phenomena, where one or more ion species are treated kinetically via standard PIC methods used in particle codes and the electrons are treated as a single charge neutralizing massless fluid. Other types of hybrid models are possible, as discussed in Winske and Quest, but hybrid codes with particle ions and massless fluid electrons have become the most common for simulating space plasma physics phenomena in the last decade, as we discuss in this paper.

  5. Hybridization and speciation in angiosperms: a role for pollinator shifts?

    Science.gov (United States)

    2010-01-01

    The majority of convincingly documented cases of hybridization in angiosperms has involved genetic introgression between the parental species or formation of a hybrid species with increased ploidy; however, homoploid (diploid) hybridization may be just as common. Recent studies, including one in BMC Evolutionary Biology, show that pollinator shifts can play a role in both mechanisms of hybrid speciation. See research article http://www.biomedcentral.com/1471-2148/10/103 PMID:20409350

  6. Bounded hybrid superiority in an avian hybrid zone: effects of mate, diet, and habitat choice.

    Science.gov (United States)

    Good, T P; Ellis, J C; Annett, C A; Pierotti, R

    2000-10-01

    There has been considerable debate in the study of hybrid zones as to whether hybrids may be superior to parental types within the area of contact (bounded hybrid superiority). In birds, naturally occurring hybridization is relatively common, and hybridization within this group always involves mate choice. If hybrids are superior, females choosing heterospecific mates should be expected to show higher fitness under the conditions prevalent in the hybrid zone. Hybrid superiority under these circumstances would reduce reinforcement and thereby help to maintain the hybrid zone. To examine this issue, we studied reproductive performances of hybrids and parental species of gulls (Larus occidentalis and Larus glaucescens) at two colonies within a linear hybrid zone along the west coast of the United States. This hybrid zone contains predominantly gulls of intermediate phenotype. Previous studies indicated that hybrids were superior to one or both parental types, but provided no data on possible mechanisms that underlie this hybrid superiority. Using a hybrid index designed specifically for these species, we identified to phenotype more than 300 individuals associated with nests, including both individual males and females within 73 pairs in the central portion of the hybrid zone and 74 pairs in the northern portion of the hybrid zone. There was little evidence of assortative mating, and what little there was resulted solely because of pairings within intergrades. In the central hybrid zone, females paired with hybrid males produced larger clutches and hatched and fledged more chicks compared with females paired to western gull males. This was a result of heavy predation on eggs in sand habitat, where male western gulls established territories. In contrast, many hybrid males established territories in vegetated cover that was less vulnerable to predation. In the northern part of the hybrid zone, clutch size did not differ among pair categories, however, there were

  7. Hybrid intermediaries

    OpenAIRE

    Cetorelli, Nicola

    2014-01-01

    I introduce the concept of hybrid intermediaries: financial conglomerates that control a multiplicity of entity types active in the "assembly line" process of modern financial intermediation, a system that has become known as shadow banking. The complex bank holding companies of today are the best example of hybrid intermediaries, but I argue that financial firms from the "nonbank" space can just as easily evolve into conglomerates with similar organizational structure, thus acquiring the cap...

  8. Hybrid composites

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2009-04-01

    Full Text Available effect was observed for the elongation at break of the hybrid composites. The impact strength of the hybrid composites increased with the addition of glass fibres. The tensile and impact properties of thermoplastic natural rubber reinforced short... panels made from conventional structural materials. Figure 3 illustrates the performance of cellular biocomposite panels against conventional systems used for building and residential construction, namely a pre- cast pre-stressed hollow core concrete...

  9. PATH COEFFICIENT ANALYSIS OF SEVERAL COMPONENTS OIL YIELD IN SUNFLOWER (HELIANTHUS ANNUUS L.

    Directory of Open Access Journals (Sweden)

    A. MIjić

    2006-06-01

    Full Text Available The objective of investigation was to analyse oil yield components and their relations by simple coefficient correlations as well as direct and indirect effects to oil yield by path analysis. Twenty-four sunflower hybrids were included in the investigation and their seven traits (plant height, head diameter, 1000 seed weight, hec- tolitar mass, grain yield, oil content and oil yield. Very strong positive correlation was estimated between grain yield and oil yield, strong positive correlation between hectolitar mass and oil yield, and middle corre- lation among oil yield and: 1000 seed weight, plaint height and oil content. There was no correlation between grain yields and oil content. Grain yield showed the strongest effect to oil yield. Oil content had lower effect to oil yield. Other traits showed no significant effect to oil yield, and their effect to oil yield was covered by indirect effect of grain yield.

  10. Acetohydroxyacid synthase (AHAS) in vivo assay for screening imidazolinone-resistance in sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Vega, T; Breccia, G; Gil, M; Zorzoli, R; Picardi, L; Nestares, G

    2012-12-01

    The objective of this work was to evaluate the in vivo acetohydroxyacid synthase (AHAS) activity response to imidazolinones and its possible use as a selection method for evaluating AHAS inhibitor resistance. In vivo AHAS assay and the comparison of parameters from dose-response curves have been used as a valid tool for comparing sunflower lines and hybrids differing in imidazolinone resistance. The sunflower resistant genotypes evaluated here were 100-fold and 20-fold more resistant compared with the susceptible line for imazethapyr and imazapyr, respectively. This assay also allowed discrimination of homozygous from heterozygous genotypes for I(mr1) locus that codify for the catalytic subunit of AHAS. The in vivo AHAS assay described in this study was useful for the selection of sunflower genotypes differing in herbicide resistance and could be a useful tool when breeding for imidazolinone resistance in sunflower.

  11. Unraveling the in vitro and in vivo metabolism of diacetoxyscirpenol in various animal species and human using ultrahigh-performance liquid chromatography-quadrupole/time-of-flight hybrid mass spectrometry.

    Science.gov (United States)

    Yang, Shupeng; De Boevre, Marthe; Zhang, Huiyan; De Ruyck, Karl; Sun, Feifei; Wang, Zhanhui; Cao, Xingyuan; Shen, Jianzhong; De Saeger, Sarah; Zhang, Suxia

    2015-11-01

    Diacetoxyscirpenol (DAS), a Fusarium mycotoxin belonging to the trichothecene type A mycotoxins, is able to contaminate food and feed worldwide. Only limited information is available regarding the metabolism of DAS. The present study used ultrahigh-performance liquid chromatography-quadrupole/time-of-flight hybrid mass spectrometry (UHPLC-Q/TOF) to investigate the in vitro phase I and II metabolism of DAS by rat, chicken, swine, goat, cow, and human liver microsomes. An extensive metabolization profile of DAS has been observed. A total of seven phase I and three phase II metabolites of DAS were detected. Among the identified molecules, four phase I metabolites (8β-hydroxy-DAS, neosolaniol, 7-hydroxy-DAS, and its epimer) and two phase II metabolites (4-deacetyl-DAS-3-glucuronic acid and 4-deacetyl-DAS-4-glucuronic acid) were identified for the first time. These results indicate that the major metabolic pathways of DAS in vitro were hydrolyzation (M1-M3), hydroxylation (M4-M7), and conjugation (M8-M10). Qualitative differences in phase I and II metabolic profiles of DAS between the five animal species and human were observed. 4-Deacetyl-DAS was the primary metabolite from liver microsomes of all species, especially human. The in vivo metabolism of DAS in rats and chickens after oral administration of DAS was also investigated and compared. The major metabolites for rats and chickens were 4-deacetyl-DAS and 7-hydroxy-DAS. These results will help to gain a more detailed insight into the metabolism and toxicity of DAS among different animal species and human. Graphical Abstract The metabolism of diacetoxyscirpenol in farm animals and human.

  12. Correlation and path coefficient analysis for protein yield in confectionary sunflower (Helianthus annuus L.

    Directory of Open Access Journals (Sweden)

    Hladni Nada

    2015-01-01

    Full Text Available The most important criteria for introducing new confectionary hybrids into the production is high protein yield. Path coefficient analysis was used to obtain information on direct and indirect effects of studied traits (seed oil content, kernel oil content, seed yield, kernel protein content, mass of 1000 seeds, kernel ratio and hull ratio on protein yield. The research was conducted during three vegetation seasons, on 22 experimental confectionary sunflower hybrids created in the breeding program at the Institute of Field and Vegetable Crops. Strong and very strong correlations were found among the largest number of examined traits. A weak negative interdependence was determined between kernel oil content, kernel protein content, mass of 1000 seeds, hull ratio, and protein yield using the analysis of simple correlation coefficients. Positive but weak correlation was determined between protein yield and seed oil content, and kernel ratio. Very strong positive correlation was determined between protein yield and seed yield (0.468**. The seed oil content had a very strong direct negative effect on protein yield (DE=-0.734**. The mass of 1000 seeds had a weak negative direct effect on protein yield. Kernel protein content and kernel oil content demonstrated a weak direct positive effect on protein yield. Path coefficient analysis of protein yield showed a very strong positive direct effect of kernel ratio (DE=1.340**, seed yield (DE=0.657** and hull ratio (DE=0.992*. These findings confirm the effect of seed yield, kernel ratio, and hull ratio on protein yield, and their importance as the selection criteria in confectionary sunflower breeding. [Projekat Ministarstva nauke Republike Srbije, br. 31025: Development of new varieties and production technology improvement of oil crops for different purposes

  13. Whole Plant Utilization of Sunflowers as a Renewable Source of Strategic Materials (Rubber).

    Science.gov (United States)

    1985-04-14

    a tetraploid . Both have a basic chromosome number of n-17. No reports of attempted hybridization with Helianthus are known (Heiser et al., 1969). A...genus includes both annuals and perennials, with considerable natural hybridization . Most species have a chromosome number of n-17. Tithonia (Mexican...domestic hybrid through hybridization with wild species. D. Breeding and Selection. Sunflowers are easily cross-bred, and hybridize so frequently in the

  14. Sunflower (Helianthus annuus L. for production of silage of the entire plant Girassol (Helianthus annuus L. para produção de silagem de planta inteira

    Directory of Open Access Journals (Sweden)

    Mikael Neumann

    2010-02-01

    Full Text Available

    The objective of the work was to describe the quantitative and qualitative characteristics referring to sunflower cultive (Helianthus annuus L. with the purpose of silage of the entire plant. The providence of conserved roughages is one strategy that can develop the productives and reproductives index of flocks in period of scarcity food, usually determinant by the low availability of pastures. The advantages of sunflower silage in comparison with the maize and sorghum is in the larger tolerance to drought, lower temperatures in the germination period (until 5 °C, smaller vegetative cycle, favoring more than one cultivation in summer with other culture and desired quality of the ensiled product. The lower content of dry matter (20 - 25% and the high content of ether extract (10 - 18% had been indicated as the main restrictions for sunflower silage, due to higher storage losses. Concerning the chemical composition of sunflower silage, contrasting with the maize, it is usual to meet larger levels of the crude protein (12% versus 9%, ether extract (14% versus 3%, acid detergent fiber (43 versus 32% and lesser levels of neutral detergent fiber (47% versus 56% and dry matter digestibility (49 versus 65%. The sunflower silage must not substitute totally the maize silage in ruminant diet, but it outstands as one forage plant option as source of energy and protein at situations of culture rotation, drought season and in the fall.

    Objetivou-se descrever as características quantitativas e qualitativas referentes à cultura do girassol (Helianthus annuus L., com a finalidade de silagem de planta inteira. O fornecimento de volumosos conservados é uma estratégia que pode incrementar os índices produtivos e reprodutivos de rebanhos. As vantagens da silagem de girassol em comparação a de gramíneas como o milho e sorgo está na maior tolerância ao déficit hídrico, a menores temperaturas na fase de germinação (até 5 °C, menor

  15. Resposta diferencial de espécies e de híbridos de citros à leprose Differential response of citrus species and hybrids to leprosis

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    Juliana Freitas-Astúa

    2008-07-01

    Full Text Available O objetivo deste trabalho foi buscar novas fontes de resistência à leprose-dos-citros, no Banco Ativo de Germoplasma do Centro APTA Citros Sylvio Moreira, Instituto Agronômico, em Cordeirópolis, SP. Foram utilizadas plantas obtidas por sementes de 26 acessos, infectadas com o vírus da leprose-dos-citros (Citrus leprosis virus - CiLV, por meio do seu vetor Brevipalpus phoenicis. O aparecimento de lesões, a partir de 21 dias após a inoculação, foi observado em 11 dos genótipos testados (42,3%. Quinze espécies, entre elas Citrus pennivesiculata e C. celebica, comportaram-se como altamente resistentes, enquanto outras, como C. keraji, foram mais suscetíveis que o padrão C. sinensis. Os dados mostraram grande variação de respostas de Citrus spp. à leprose, com elevado número de espécies resisentes, que podem ser utilizadas como fonte de resistência à doença em programas de melhoramento.The objective of this work was to prospect for new sources of resistance to leprosis in the Citrus Germplasm Bank of Centro APTA Citros Sylvio Moreira, Instituto Agronômico, in Cordeirópolis, SP, Brazil. Plants obtained through seeds from 26 citrus accessions were mite-infected with Citrus leprosis virus (CiLV. Typical lesions started to appear in 11 genotypes (42.3% of the tested accessions 21 days after inoculation. Fifteen species, among them Citrus pennivesiculata and C. celebica, behaved as highly resistant, while other genotypes, as C. keraji, were more susceptible than the standard C. sinensis. The data showed a wide variation in the response of Citrus spp. to leprosis, with a large number of resistant species, wich can be used as source of resistance to this disease, in breeding programs.

  16. Evaluation of Cover Crops with Potential for Use in Anaerobic Soil Disinfestation (ASD) for Susceptibility to Three Species of Meloidogyne.

    Science.gov (United States)

    Kokalis-Burelle, Nancy; Butler, David M; Rosskopf, Erin N

    2013-12-01

    Several cover crops with potential for use in tropical and subtropical regions were assessed for susceptibility to three common species of root-knot nematode, Meloidogyne arenaria, M. incognita, and M. javanica. Crops were selected based on potential use as organic amendments in anaerobic soil disinfestation (ASD) applications. Nematode juvenile (J2) numbers in soil and roots, egg production, and host plant root galling were evaluated on arugula (Eruca sativa, cv. Nemat), cowpea (Vigna unguiculata, cv. Iron & Clay), jack bean (Canavalia ensiformis, cv. Comum), two commercial mixtures of Indian mustard and white mustard (Brassica juncea & Sinapis alba, mixtures Caliente 61 and Caliente 99), pearl millet (Pennisetum glaucum, cv. Tifleaf III), sorghum-sudangrass hybrid (Sorghum bicolor × S. bicolor var. sudanense, cv. Sugar Grazer II), and three cultivars of sunflower (Helianthus annuus, cvs. 545A, Nusun 660CL, and Nusun 5672). Tomato (Solanum lycopersicum, cv. Rutgers) was included in all trials as a susceptible host to all three nematode species. The majority of cover crops tested were less susceptible than tomato to M. arenaria, with the exception of jack bean. Sunflower cv. Nusun 5672 had fewer M. arenaria J2 isolated from roots than the other sunflower cultivars, less galling than tomato, and fewer eggs than tomato and sunflower cv. 545A. Several cover crops did not support high populations of M. incognita in roots or exhibit significant galling, although high numbers of M. incognita J2 were isolated from the soil. Arugula, cowpea, and mustard mixture Caliente 99 did not support M. incognita in soil or roots. Jack bean and all three cultivars of sunflower were highly susceptible to M. javanica, and all sunflower cultivars had high numbers of eggs isolated from roots. Sunflower, jack bean, and both mustard mixtures exhibited significant galling in response to M. javanica. Arugula, cowpea, and sorghum-sudangrass consistently had low numbers of all three

  17. Hybridization between invasive Spartina Densiflora (Poaceae) and native S. Foliosa in San Francisco Bay, California, USA

    Science.gov (United States)

    Rapid evolution in contemporary time can result when related species, brought together through human-aided introduction, hybridize. The evolutionary consequences of post introduction hybridization range from allopolyploid speciation to extinction of species through genetic amalg...

  18. Interspecific Hybridization within Ornamental Plants

    DEFF Research Database (Denmark)

    Kuligowska, Katarzyna

    The economic importance of the ornamental plant industry requires constant development of novel and high quality varieties. Traits attractive for production of new ornamental plants may not be available within the commercial cultivars, but broad genetic variation is present within the plant genera...... commercially important genera of ornamental plants: Kalanchoë and Hibiscus. The nature of hybridization barriers hampering hybrid production was investigated during pre- and post-fertilization stages. For each genus the interspecific crosses of Kalanchoë species and Hibiscus species, abnormal germination...

  19. Interspecific Hybridization within Ornamental Plants

    DEFF Research Database (Denmark)

    Kuligowska, Katarzyna

    The economic importance of the ornamental plant industry requires constant development of novel and high quality varieties. Traits attractive for production of new ornamental plants may not be available within the commercial cultivars, but broad genetic variation is present within the plant genera...... commercially important genera of ornamental plants: Kalanchoë and Hibiscus. The nature of hybridization barriers hampering hybrid production was investigated during pre- and post-fertilization stages. For each genus the interspecific crosses of Kalanchoë species and Hibiscus species, abnormal germination...

  20. Effect of antioxidant butylated hydroxyl anisole on the thermal or oxidative stability of sunflower oil (Helianthus Annuus) by ultrasonic.

    Science.gov (United States)

    Murari, Satish Kumar; Shwetha, M V

    2016-01-01

    The aim of the current investigation was to evaluate the efficiency of butylated hydroxyl anisole (BHA) as an antioxidant in sunflower oil (Helianthus Annuus). The oxidation stability of sunflower oil have been investigated by the effects of varying amounts of BHA. The antioxidant incorporated sunflower oil system and control edible oil were subjected to heating at 180 ± 5 °C continuously for a period of 4 h per day for consecutive 4 days. The parameters used to assess the thermal degradation and oxidation properties of the oils include ultrasonic velocity, viscosity, density and peroxide value. The fatty acid compositions of the oils were measured by gas chromatography. Adiabatic compressibility, intermolecular free length, relaxation time and acoustic impedance have been calculated from experimental data. Viscosity, density and ultrasonic velocity change in control oil is from 3.72 × 10(-2) to 13.2 × 10(-2) Nsm - 2, 918 to 994 kg/m3 and 1412 to 1484 m/s respectively and in sunflower oil with 200 ppm BHA is from 3.88 × 10(-2) to 7.52 × 10(-2) Nsm - 2, 926 to 962 kg/m3 and 1418 to 1463 m/s respectively for 16 h of heat treated oil. The ultrasonic results obtained have shown reduction in thermal degradation and improvement in oxidation stability of antioxidant loaded oil in comparison to base oil. Hence, it can be recommended that sunflower oil with 200 ppm BHA can be used for frying without adverse effect on physical properties. The ultrasonic velocity can be used for assessment of stability of frying oil.

  1. THE EFFECTS OF GAMMA RADIATION ON CRUDE OIL YIELD AND GERMINATION OF SUNFLOWER-TANAY VARIETY (HELIANTHUS ANNUUS L. SEEDS

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    H. E. VAİZOĞULLAR

    2014-06-01

    Full Text Available This study was conducted to investigate the effects of gamma rays on crude oil yield, seedling growth, germination and antimicrobial activity of sunflower (Helianthus annuus. As plant materials, sunflower variety Tanay seeds were used and irradiated with doses of 0 (control, 100, 200, 300, 400 and 500 Gy gamma radiation. Irradiation was performed in a cesium (Ce137 Gammacell 3000 Elan source, dose rate about 9.75 Gy/min (2900 Ci in the Pamukkale University Faculty of Medicine in the department of the radiological.To determine seed viability, tetrazolium chloride (TTC test was performed. Moisture amount of seeds were also measured by AOCS standarts and seeds were subjected to germination tests. The seeds were treated with 100 ppm doses of GA3 for 24 hours (GA, soaking for 24 hours (SB, preheating for 24 hours in a week (PH and precooling for 24 hours in a week (PC for optimization of germination.The result showed that the highest crude oil yield was also obtained from 400 Gy. As a result of testing of seed viability, 95% viability in seeds was determined. In 12L/12D light photoperiod, 25% germination in seeds was detected at GA application the highest, the lowest 5% germination in seeds was determined in PC application. It was found that minimum and maximum values ranged between 5.72and 10.81% for humidity rate.Extraction of the seed of Sunflower-Tanay was done with soxhlet apparatus using petroleum ether by hot continuous extraction for 6 hours. Antimicrobial activity of Sunflower-Tanay extract were tested by a disk diffusion method. Extracts of the H.annuus L.(sunflower-Tanay showed no antimicrobial activity against M.luteus NCIMB 13267 and E. coli ATCC 25922.

  2. Cloning and functional characterization of two abiotic stress-responsive Jerusalem artichoke (Helianthus tuberosus) fructan 1-exohydrolases (1-FEHs).

    Science.gov (United States)

    Xu, Huanhuan; Liang, Mingxiang; Xu, Li; Li, Hui; Zhang, Xi; Kang, Jian; Zhao, Qingxin; Zhao, Haiyan

    2015-01-01

    Two fructan hydrolases were previously reported to exist in Jerusalem artichoke (Helianthus tuberosus) and one native fructan-β-fructosidase (1-FEH) was purified to homogeneity by SDS-PAGE, but no corresponding cDNA was cloned. Here, we cloned two full-length 1-FEH cDNA sequences from Jerusalem artichoke, named Ht1-FEH I and Ht1-FEH II, which showed high levels of identity with chicory 1-FEH I and 1-FEH II. Functional characterization of the corresponding recombinant proteins in Pichia pastoris X-33 demonstrated that both Ht1-FEHs had high levels of hydrolase activity towards β(2,1)-linked fructans, but low or no activity towards β(2,6)-linked levan and sucrose. Like other plant FEHs, the activities of the recombinant Ht1-FEHs were greatly inhibited by sucrose. Real-time quantitative PCR analysis showed that Ht1-FEH I transcripts accumulated to high levels in the developing leaves and stems of artichoke, whereas the expression levels of Ht1-FEH II increased in tubers during tuber sprouting, which implies that the two Ht1-FEHs play different roles. The levels of both Ht1-FEH I and II transcript were significantly increased in the stems of NaCl-treated plants. NaCl treatment also induced transcription of both Ht1-FEHs in the tubers, while PEG treatments slightly inhibited the expression of Ht1-FEH II in tubers. Analysis of sugar-metabolizing enzyme activities and carbohydrate concentration via HPLC showed that the enzyme activities of 1-FEHs were increased but the fructose content was decreased under NaCl and PEG treatments. Given that FEH hydrolyzes fructan to yield Fru, we discuss possible explanations for the inconsistency between 1-FEH activity and fructan dynamics in artichokes subjected to abiotic stress.

  3. Nuclear magnetic resonance study of the solution properties of the polypeptide neurotoxin I from the sea anemone Stichodactyla helianthus

    Energy Technology Data Exchange (ETDEWEB)

    Norton, R.S.; Cossins, A.I.; Kem, W.R. (Univ. of New South Wales, Kensington (Australia))

    1989-02-21

    The solution properties of the polypeptide neurotoxin I from the sea anemone Stichodactyla helianthus (Sh I) have been investigated by high-resolution H nuclear magnetic resonance (NMR) spectroscopy at 300 MHz. The pH dependence of the spectra has been examined over the range 1.1-12.2 at 27{degree}C. Individual pK{sub a} values have been obtained for the {alpha}-ammonium group of Ala-1 (8.6) and the side chains of Glu-8 (3.7), Tyr-36 (10.9), and Tyr-37 (10.8). For the remaining seven carboxyl groups in the molecule, four pK{sub a} values can be clearly identified. The five Lys residues titrate in the range 10.5-11, but individual pK{sub a} values could not be obtained because of peak overlap. Conformational changes associated with the protonation of carboxylates occur below pH 4, while in the alkaline pH range major unfolding occurs above pH 10. The molecule also unfolds at elevated temperatures. Exchange of the backbone amide protons has been monitored at various values of pH and temperature in the ranges pH 4-5 and 12-27{degree}C. Comparison of these properties of Sh I in solution with those of the related polypeptides anthopleurin A and Anemonia sulcata toxins I and II indicates that Sh I is less stable thermally and that there are some significant differences in the ionic interactions that maintain the tertiary structure. The solvent accessibility of aromatic residues has been probed with photochemically induced dynamic nuclear polarization NMR at 360 MHz.

  4. Foliar-applied glyphosate substantially reduced uptake and transport of iron and manganese in sunflower (Helianthus annuus L.) plants.

    Science.gov (United States)

    Eker, Selim; Ozturk, Levent; Yazici, Atilla; Erenoglu, Bulent; Romheld, Volker; Cakmak, Ismail

    2006-12-27

    Evidence clearly shows that cationic micronutrients in spray solutions reduce the herbicidal effectiveness of glyphosate for weed control due to the formation of metal-glyphosate complexes. The formation of these glyphosate-metal complexes in plant tissue may also impair micronutrient nutrition of nontarget plants when exposed to glyphosate drift or glyphosate residues in soil. In the present study, the effects of simulated glyphosate drift on plant growth and uptake, translocation, and accumulation (tissue concentration) of iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) were investigated in sunflower (Helianthus annuus L.) plants grown in nutrient solution under controlled environmental conditions. Glyphosate was sprayed on plant shoots at different rates between 1.25 and 6.0% of the recommended dosage (i.e., 0.39 and 1.89 mM glyphosate isopropylamine salt). Glyphosate applications significantly decreased root and shoot dry matter production and chlorophyll concentrations of young leaves and shoot tips. The basal parts of the youngest leaves and shoot tips were severely chlorotic. These effects became apparent within 48 h after the glyphosate spray. Glyphosate also caused substantial decreases in leaf concentration of Fe and Mn while the concentration of Zn and Cu was less affected. In short-term uptake experiments with radiolabeled Fe (59Fe), Mn (54Mn), and Zn (65Zn), root uptake of 59Fe and 54Mn was significantly reduced in 12 and 24 h after application of 6% of the recommended dosage of glyphosate, respectively. Glyphosate resulted in almost complete inhibition of root-to-shoot translocation of 59Fe within 12 h and 54Mn within 24 h after application. These results suggest that glyphosate residues or drift may result in severe impairments in Fe and Mn nutrition of nontarget plants, possibly due to the formation of poorly soluble glyphosate-metal complexes in plant tissues and/or rhizosphere interactions.

  5. Genetic diversity and population structure in cultivated sunflower and a comparison to its wild progenitor, Helianthus annuus L.

    Science.gov (United States)

    Mandel, J R; Dechaine, J M; Marek, L F; Burke, J M

    2011-09-01

    Crop germplasm collections are valuable resources for ongoing plant breeding efforts. To fully utilize such collections, however, researchers need detailed information about the amount and distribution of genetic diversity present within collections. Here, we report the results of a population genetic analysis of the primary gene pool of sunflower (Helianthus annuus L.) based on a broad sampling of 433 cultivated accessions from North America and Europe, as well as a range-wide collection of 24 wild sunflower populations. Gene diversity across the cultivars was 0.47, as compared with 0.70 in the wilds, indicating that cultivated sunflower harbors roughly two-thirds of the total genetic diversity present in wild sunflower. Population structure analyses revealed that wild sunflower can be subdivided into four genetically distinct population clusters throughout its North American range, whereas the cultivated sunflower gene pool could be split into two main clusters separating restorer lines from the balance of the gene pool. Use of a maximum likelihood method to estimate the contribution of the wild gene pool to the cultivated sunflower germplasm revealed that the bulk of the cultivar diversity is derived from two wild sunflower population genetic clusters that are primarily composed of individuals from the east-central United States, the same general region in which sunflower domestication is believed to have occurred. We also identified a nested subset of accessions that capture as much of the allelic diversity present within the sampled cultivated sunflower germplasm collection as possible. At the high end, a core set of 288 captured nearly 90% of the alleles present in the full set of 433, whereas a core set of just 12 accessions was sufficient to capture nearly 50% of the total allelic diversity present within this sample of cultivated sunflower.

  6. Effect of Chlorocholine Chloride (CCC on the Plants’ Height and Inulin Content in Jerusalem Artichoke (Helianthus tuberosus L.

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