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Sample records for sunflower hybrid species

  1. 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.

  2. Backcrosses in interspecific hybridization in sunflower

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    Atlagić Jovanka

    2003-01-01

    Full Text Available When incorporating desirable traits (resistance to causal agents of various diseases from the wild relatives into the cultivated sunflower, some undesirable ones are introduced too (branching, small head diameter, low oil content, etc. To overcome this problem, backcrosses (F1 interspecific hybrids x cultivated sunflower are used, although very often desirable traits are lost in the process. Cytological analysis (meiosis and pollen viability and molecular markers (RAPD were used to estimate what portion of the parental species genome was present in (be interspecific hybrids of the F1 and BC1F1 generations. The results showed that the percentage of irregularities at meiosis increased from F1 to BC1F1 gen. They also indicated the presence of aneuploids and sterility in the cross between the hexaploid species H.rigidus and cultivated sunflower. The genetic distance between the parents was 83%, that between H.rigidus and the F1 hybrid 54 61%, and that between H.annuus and F1 hybrid 70-76%. In the BC1F1 generation, the genetic distance from Hannuus decreased to 58-66% and that from H.rigidus increased to 69-76%.

  3. Contribution of interspecific hybridization to sunflower breeding

    OpenAIRE

    Christov M.

    2012-01-01

    This investigation is directed at improving sunflower using hybrid forms resulted from interspecific hybridization. The aim is to create new B/A and R lines from interspecific hybrid forms that are resistant to diseases, the parasite broomrape, herbicides, and other stress factors and are characterized with high combining ability and to obtain on this basis highly productive oilseed sunflower hybrids with varied fatty acid composition of oil. The investigat...

  4. Sunflower

    Science.gov (United States)

    Sunflower (Helianthus annuus L.) is a species native to North America. It is a relatively new crop in the USA with commercialization starting around 1970. The high oil content sunflower seed changed the economics of producing and crushing sunflower seed for oil, making it attractive for growers. A n...

  5. Contribution of interspecific and intergeneric hybridization to sunflower breeding

    OpenAIRE

    Christov M.

    2013-01-01

    This investigation was directed to sunflower improvement using hybrid forms resulted from wide hybridization. The aim was to create new B/A and R lines from interspecific and intergeneric hybrids resistant to diseases, parasite broomrape, herbicides, other stress factors and with high combining ability in highly productive oil-type sunflower hybrids with varied fatty acid contents. The confectionary hybrids should have a high kernel protein content and amin...

  6. Development of sunflower hybrids tolerant to tribenuron methyl

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    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.

  7. Interaction hybrid × planting date for oil yield in sunflower

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    Balalić Igor M.

    2010-01-01

    Full Text Available The aim of the study was to assess the effects of hybrids and planting dates as well as their interaction on oil yield in sunflower for three-year experiment (2005, 2006, 2007. Three sunflower hybrids (Miro, Rimi and Pobednik and eight planting dates were included in the experiment. AMMI (Additive Main Effects and Multiplicative Interaction analysis is one of the mainly used multiplicative models, which evaluates main effects and also interaction. The interaction was detected by using AMMI1 biplot. Oil yield was predominantly influenced by the year of growing (58.9%, then by planting date (12.9% and by hybrid (10.7%. All interactions were significant as well. AMMI ANOVA showed high significance of both IPC1 and IPC2. The contribution of IPC1 was 77.5%. Hybrids Miro and Pobednik showed no significant differences in the mean values, which were higher than average. However, the hybrid Miro showed the highest stability for oil yield. Hybrid Rimi, with the lowest mean value, was the most unstable for the examined character. Oil yield was higher in earlier than in later planting dates. Graphical presentation of AMMI1 in the form of biplot could facilitate the choice of stable hybrids and planting dates for desired characters in sunflower.

  8. 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.

  9. 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...

  10. Irrigation method does not affect wild bee pollinators of hybrid sunflower

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    Hillary Sardiñas

    2016-09-01

    Full Text Available Irrigation method has the potential to directly or indirectly influence populations of wild bee crop pollinators nesting and foraging in irrigated crop fields. The majority of wild bee species nest in the ground, and their nests may be susceptible to flooding. In addition, their pollination of crops can be influenced by nectar quality and quantity, which are related to water availability. To determine whether different irrigation methods affect crop pollinators, we compared the number of ground-nesting bees nesting and foraging in drip- and furrow-irrigated hybrid sunflower fields in the Sacramento Valley. We found that irrigation method did not impact wild bee nesting rates or foraging bee abundance or bee species richness. These findings suggest that changing from furrow irrigation to drip irrigation to conserve water likely will not alter hybrid sunflower crop pollination.

  11. Resistance of sunflower hybrids to imazamox and tribenuron-methyl

    DEFF Research Database (Denmark)

    Bozic, D; Saric, M; Malidza, G;

    2012-01-01

    The response of the imazamox resistant and susceptible sunflower hybrids Rimi and S to imazamox and of tribenuron-methyl resistant and susceptible hybrids Rsu and S to tribenuron-methyl was investigated both in a whole-plant bioassay and in field experiments. Plants were treated post...... concentrations was determined in vitro. Pronounced differences were noted between Rimi and S hybrids and between Rsu and S hybrids in the vegetative parameters and ALS activity. Namely, Rimi hybrid was 9e64-fold more resistant than S for vegetative parameters and about 3000-fold for ALS activity, while Rsu...... hybrid was 14e56-fold more resistant than S for vegetative parameters, and about 2600-fold for ALS activity....

  12. Borneo: The new NS sunflower confectionary type hybrid

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    Hladni Nada

    2009-01-01

    Full Text Available At the Institute of Field and Vegetable Crops in Novi Sad, beside the basic direction in sunflower breeding, the creation of standard hybrids with high oil content with high seed and oil yield, hybrids are being created for special confectionery purposes directed towards the final kernel products. In this program, apart from breeding in order to improve main seed yield components, special attention is given to the increase of protein content and the quality with the decrease of seed oil content, to the increase of the weight of 1000 seeds and to the decrease of content of the shell. Two-line SC hybrid was created by crossing the cytoplasmatic male sterile line of the mother with a father line with fertility restoration genes. Borneo is a high protein confectionary type hybrid that has been registered in Slovakia (EU in 2009. It contains successfully combined genes responsible for high genetic potential for yield and valuable technical and technological seed traits. The hybrid is adequate for nutrition, dehuling and kernel production. Borneo is a medium early hybrid with the genetic potential for yield of over 4,5t/ha and its seed oil content is under 43%. .

  13. Interdependence of yield and yield components of confectionary sunflower hybrids

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    Hladni Nada

    2011-01-01

    Full Text Available The two most important criteria for introducing new confectionary hybrids into production are high seed and protein yield. That is why it is important to find the traits that are measurable, and that at the same time show a strong correlation with seed and protein yield, so that they can be used as a criteria for confectionary hybrid breeding. Results achieved during 2008 at the locations Rimski Šančevi (Region of Vojvodina and Kula (Central Serbia show that the new confectionary hybrids are expressing higher seed yields in comparison to standards (Vranac and Cepko though with a lower seed oil content. A very strong positive correlation was determined between seed yield and seed protein content, kernel content and mass of 1000 seeds. A very strong positive correlation was determined between seed protein content, seed yield and mass of 1000 seeds, with protein yield. This indicates that seed yield, seed protein content and mass of 1000 seeds have a high influence on protein yield. The degree of interdependence between different traits is a sign of direction which is supposed to facilitate better planning of sunflower breeding program.

  14. 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.

  15. RESULTS ON THE FLOWERING STAGE IN THE ROMANIAN-GROWN SUNFLOWER HYBRIDS

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    V. ION

    2013-12-01

    Full Text Available The present paper presents the results of the research carried out on forty sunflowerhybrids in southern Romania (15 km far from northeastern Bucharest, under the2004 and 2006 climatic conditions, regarding the flowering stage, the period andthe duration of flowering process within the crop, respectively. The studied hybridswere the following: Favorit, Festiv, Florina, Jupiter, Alcazar, Top 75, Venus, Alex,Saturn, Minunea, HS 2442, HS 2606, Milenium, Romina, Performer, Select, Justin,Splendor, Hercule, Felix, and twenty foreign hybrids cultivated in Romania:Huracan, Kasol, Lindor, Masai, Mateol, Podium, Saxo, Sunko, Fly, Rigasol, RigasolOR, Fleuret OR, Arena, Melody, NK Armoni, Alexandra, NK Dolbi, NK Ferti,Opera PR, Sanay.At the studied sunflower hybrids were performed the following determinations:sum of growing degree days (GDD from plant emergency (i.e. when 75% ofthe plants emerged to the beginning of the flowering process within the crop(i.e. when 10% of the sunflower heads are flowered;date for the first sunflower heads flowering;date for the beginning of the flowering process, i.e. when 10% of the sunflowerheads have flowered in the whole crop;date for the plain flowering phase, i.e. when 50% of the total sunflower headshave flowered;date for the full-flower phase, i.e. when all the sunflower head in the crop haveflowered;date for the time when only 10% of the sunflower heads were still in flower;date for the end of flowering, i.e. when no sunflower heads are in flower in thewhole crop;number of days between different flowering stages.

  16. No-tillage system applied to the sunflower (hybrid pioneer PR64E83) resistant to the tribenuron-methyl in the conditions from Romania.

    Science.gov (United States)

    Sarpe, Nicolae; Poienaru, Stefan; Maschio, Mirco

    2007-01-01

    In the year 2006, the first experience with the NO-TILLAGE system for sunflower crops was organized in Romania, using the Pioneer PR64E83 sunflower hybrid resistant to the tribenuron-methyl herbicide. The experience took place in the Danube river flood plain, on an alluvial soil with a content between 3.1-4.5% and a content of clay of 34-40%. In the conventional system, in the fall of the year 2005, autumn ploughing was carried out, along with harrowing, and in spring the land was tilled two more times, using both the disk and the harrow. Before sowing, the land was prepared by using the combiner-machine. After the sunflower sprouted, three-time mechanical hoeing between the rows, as well as three-time manual hoeing on the sunflower row were performed. In the no-tillage system, no autumn ploughing, nor any other soil work were performed, and the sunflower was sowed directly, by using the Gaspardo seeder. Before sowing, the soil was covered in proportion of 70% by species of weeds of the Cirsum, Sonchus and Polygonum amphibium type. To destroy these species of weeds, 3 days before sowing, the soil was treated with the Roundup herbicide in a dose of 7 litres/ha. After the sunflower sprouted, when the plants had 4-5 leaves, the following sulphonylurea herbicides were applied post-emergently. (1) Express 50SG--which contains tribenuron-methyl (2) Granstar 75DF--which contains 75% tribenuron-methyl (3) Titus 25DF--which contains 25% rimsulfuron (4) Mistral--which contains 40 g/L nicosulfuron (5) Lintur 70WG--which contains 4.1% triasulfuron + 65.9% dicamba (6) Peak 75WG--which contains 75% prosulfuron The Express 50SG and Granstar 75DF herbicides were selective for the sunflower hybrid PR64E83, and the other herbicides although belonging o the same sulphonylurea group, they proved to have a very phytotoxic effect upon the sunflower crop. In the report, selectivity is presented depending on the dose of herbicide, weed control and sunflower production.

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

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    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. IMPORTANCE OF STORAGE CONDITIONS AND SEED TREATMENT FOR SUNFLOWER HYBRIDS SEEDS GERMINATION

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    Goran Krizmanić

    2014-12-01

    Full Text Available In this research we have determined germination energy and germination of seeds of sunflower hybrids ‘Luka’ and ‘Apolon’, at the beginning of storage and 6, 12 and 18 months after of storage period (2011-2012 in the floor concrete storage at two different air temperatures and humidity (S-1: air temperature 15-18°C and relative air humidity 65-70% as well as in climate chamber (S-2: air temperature 10-12°C and relative air humidity 60-65%, stored in four treatments (Control: processed-untreated seed; T-1: treated with A.I. metalaxyl-M; T-2: treated with A.I. metalaxyl-M + A.I. imidacloprid and T-3: treated with A.I. metalaxyl-M + A.I. clothianidin. Based on the obtained results we have determined that sunflower hybrid ‘Luka’, compared to hybrid ‘Apolon’, in the given storage conditions and with the same seed treatment has 5-8% higher germination energy and seed germination and that in climate chamber both hybrids have 5-7% higher germination energy. Seed treatment of both sunflower hybrids with A.I. imidacloprid maximally reduced initial germination energy and seed germination in all tested periods and conditions of storage. On the average, natural seed, after 18 months of storage did not have better seed quality compared to seed treated with A.I. metalaxyl-M while other treatments had more significant influence on reduction of germination energy and seed germination, 6-15%. On the average, compared to other variants, seeds treated with A.I. metalaxyl-M after 18 months of storage in both storage conditions had higher germination energy by 4-15%, and seed germination by 2-12%.

  19. Interdependence of yield and yield components of confectionary sunflower hybrids

    OpenAIRE

    Hladni Nada; Jocić Siniša; Miklič Vladimir; Saftić-Panković Dejana; Kraljević-Balalić Marija

    2011-01-01

    The two most important criteria for introducing new confectionary hybrids into production are high seed and protein yield. That is why it is important to find the traits that are measurable, and that at the same time show a strong correlation with seed and protein yield, so that they can be used as a criteria for confectionary hybrid breeding. Results achieved during 2008 at the locations Rimski Sancevi (Region of Vojvodina) and Kula (Central Serbia) show t...

  20. Effects of High Temperature and Water Stress on Seed Germination of the Invasive Species Mexican Sunflower

    Science.gov (United States)

    Wen, Bin

    2015-01-01

    Mexican sunflower is native to Mexico and Central America and was introduced into China early last century. Now it has widely naturalized and is exhibiting increasing invasiveness in South China. As this species often dominates bare ground, a habitat characterized by extreme fluctuation in temperature and water, it is reasonable to hypothesize that it has special adaptations to high temperature and water stress. Using laboratory experiments to simulate these stresses, this study investigated the response of Mexican sunflower seed germination to temperature and water stress, and compared these responses with those previously reported for another invasive, bamboo piper, which is confined to relatively cool and moist habitats in Xishuangbanna. As expected, Mexican sunflower seeds exhibited higher tolerance to these stresses than bamboo piper. Germination of Mexican sunflower seeds was highest at 15–30°C, but significant numbers of seeds germinated and formed seedlings at 10°C and 35°C, at which no bamboo piper seeds formed seedlings, indicating a wider temperature range for germination than the latter. Roughly half the seeds survived 240 h continuous heat treatment and up to 15 h daily periodical heat treatment at 40°C, while bamboo piper seeds were mostly killed by these treatments. About 20% of Mexican sunflower but no bamboo piper seeds germinated after heat treatment for 30 min at 80°C. Germination was completely inhibited in bamboo piper seeds at -0.6 mPa, while 20–60% of Mexican sunflower seeds germinated depending on PEG or NaCl as osmoticum. This higher tolerance in Mexican sunflower seeds accords with its stronger invasiveness in this area. This comparison between two plant invaders demonstrates that invasiveness is not an all-or-nothing situation, and that adaptation to local habitats is a critical determinant of successful invasiveness for an alien plant. PMID:26509675

  1. Effects of High Temperature and Water Stress on Seed Germination of the Invasive Species Mexican Sunflower.

    Science.gov (United States)

    Wen, Bin

    2015-01-01

    Mexican sunflower is native to Mexico and Central America and was introduced into China early last century. Now it has widely naturalized and is exhibiting increasing invasiveness in South China. As this species often dominates bare ground, a habitat characterized by extreme fluctuation in temperature and water, it is reasonable to hypothesize that it has special adaptations to high temperature and water stress. Using laboratory experiments to simulate these stresses, this study investigated the response of Mexican sunflower seed germination to temperature and water stress, and compared these responses with those previously reported for another invasive, bamboo piper, which is confined to relatively cool and moist habitats in Xishuangbanna. As expected, Mexican sunflower seeds exhibited higher tolerance to these stresses than bamboo piper. Germination of Mexican sunflower seeds was highest at 15-30°C, but significant numbers of seeds germinated and formed seedlings at 10°C and 35°C, at which no bamboo piper seeds formed seedlings, indicating a wider temperature range for germination than the latter. Roughly half the seeds survived 240 h continuous heat treatment and up to 15 h daily periodical heat treatment at 40°C, while bamboo piper seeds were mostly killed by these treatments. About 20% of Mexican sunflower but no bamboo piper seeds germinated after heat treatment for 30 min at 80°C. Germination was completely inhibited in bamboo piper seeds at -0.6 mPa, while 20-60% of Mexican sunflower seeds germinated depending on PEG or NaCl as osmoticum. This higher tolerance in Mexican sunflower seeds accords with its stronger invasiveness in this area. This comparison between two plant invaders demonstrates that invasiveness is not an all-or-nothing situation, and that adaptation to local habitats is a critical determinant of successful invasiveness for an alien plant.

  2. 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 ...

  3. Effect of hybrid, storage conditions and seed protection on sunflower field emergence

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    Mrđa Jelena

    2010-01-01

    Full Text Available Seed emergence under field conditions decisively and directly determines the number of plants per hectare, which is one of three basic components of yield in the plant world. Influence of chemical treatment on field emergence of three commercial sunflower hybrids stored in different conditions was tested in 2007 and 2008 on experimental field of Institute of Field and Vegetable Crops in Novi Sad. On average, hybrid H1 had the highest value of field emergence (88.79% and for chemical treatment fl udioxonil + metalaxyl + imidacloprid (87.71%. Seed kept in common storage had the highest emergence value in fi eld (87.92%. Seed treated with fl udioxonil + metalaxyl + imidacloprid and stored for one year in common storage had the highest field emergence (90.18%. Considering interaction between storage conditions and genotype, hybrid H1 seed sown after chemical treatment had the highest field emergence (91.82% and seed kept in common storage (90.48%. Hybrid H1 seed compared with other two had the highest field emergence treated with fludioxonil + metalaxyl + imidacloprid (91.84%.

  4. Studies on the species, density, frequency and sociability of sunflower weeds in Erzurum

    OpenAIRE

    ZENGİN, Hüseyin

    1999-01-01

    This study was carried out in order to determine the species, density, frequency and sociability of weeds in sunflower in Pasinler and Köprüköy districts of Erzurum in 1990 and 1995. In the study, 85 different weed species belonging to 27 families were identified with a density of 65.57 weeds per square meter on average. The number of species recorded in Pasinler and Köprüköy was 67 and 60 with a density of 63.35 and 67.78 weeds per meter square respectively. Sinapis arvensis was a predom...

  5. Analysis of relations between crop temperature indices and yield of different sunflower hybrids foliar treated by biopreparations

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    Kovár Marek

    2016-04-01

    Full Text Available The application of biological active preparations (BAPs and remote-sensing control in the management of agronomic intervention are an important part of successful crop cultivation. The effects of foliar application of two BAPs (containing amino acids or Abiestins® on yield and yield-forming, as well eco-physiological traits calculated from infrared thermographs data (crop water stress index, CWSI and index of stomatal conductance, Ig of three hybrids of sunflower were studied in field poly-factorial experiments, realised during two years (2012 and 2013. The results showed that the application of selected BAPs has contributed to an increase of the sunflower yield, in particular through an increase in the weight of thousand seeds (rp = 0.761, P < 0.001. Similarly, oil content in achenes was significantly higher in treatments with BAPs, mainly with preparation containing free amino acids. The study describes the quantitative relationship between yield and quality of sunflower production (rp = −0.41, P < 0.01. Selected hybrids of sunflower in two growth stages showed the significant differences in CWSI and Ig (both at P < 0.01, respectively. An analysis of negative linear relation between the yield of achenes and CWSI (rp = −0.654, P < 0.001 confirmed that higher value of plant stress resulted in a smaller yield and vice-versa. The opposite trend was observed between yield and Ig index (rp = 0.576, P < 0.001. The data obtained from IR thermography can be used for monitoring the physiological health of sunflower plants, as well in potential prediction and control of yield.

  6. 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.

  7. Reactive oxygen species, abscisic acid and ethylene interact to regulate sunflower seed germination.

    Science.gov (United States)

    El-Maarouf-Bouteau, Hayat; Sajjad, Yasar; Bazin, Jérémie; Langlade, Nicolas; Cristescu, Simona M; Balzergue, Sandrine; Baudouin, Emmanuel; Bailly, Christophe

    2015-02-01

    Sunflower (Helianthus annuus L.) seed dormancy is regulated by reactive oxygen species (ROS) and can be alleviated by incubating dormant embryos in the presence of methylviologen (MV), a ROS-generating compound. Ethylene alleviates sunflower seed dormancy whereas abscisic acid (ABA) represses germination. The purposes of this study were to identify the molecular basis of ROS effect on seed germination and to investigate their possible relationship with hormone signalling pathways. Ethylene treatment provoked ROS generation in embryonic axis whereas ABA had no effect on their production. The beneficial effect of ethylene on germination was lowered in the presence of antioxidant compounds, and MV suppressed the inhibitory effect of ABA. MV treatment did not alter significantly ethylene nor ABA production during seed imbibition. Microarray analysis showed that MV treatment triggered differential expression of 120 probe sets (59 more abundant and 61 less abundant genes), and most of the identified transcripts were related to cell signalling components. Many transcripts less represented in MV-treated seeds were involved in ABA signalling, thus suggesting an interaction between ROS and ABA signalling pathways at the transcriptional level. Altogether, these results shed new light on the crosstalk between ROS and plant hormones in seed germination.

  8. GROWTH PERFORMANCE AND FEED CONVERSION RATIO (FCR OF HYBRID FINGERLINGS (CATLA CATLA X LABEO ROHITA FED ON COTTONSEED MEAL, SUNFLOWER MEAL AND BONE MEAL

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    T. SAHZADI, M. SALIM, UM-E-KALSOOM AND K. SHAHZAD

    2006-10-01

    Full Text Available An experiment was conducted in six glass aquaria to study the growth performance and feed conversion ratio (FCR of hybrid fingerlings (Catla catla x Labeo rohita fed on sunflower meal, cottonseed meal and bone meal. Two replicates for each ingredient were followed. The feed was supplied at the rate of 4% of wet body weight of fingerlings twice a day. The hybrid (Catla catla x Labeo rohita fingerlings gained highest body weight (1.62 ± 0.0 g on sunflower meal, followed by cottonseed meal (1.61 ± 0.01 g and bone meal (1.52 ± 0.0 g. The total length obtained by hybrid fish was 6.35 ± 0.05 cm on sunflower meal, 6.12 ± 0.05 cm on cottonseed meal and 5.85 ± 0.05 cm on bone meal. The overall mean values of FCR were lower (better on sunflower meal (1.78 ± 0.05, followed by cottonseed meal (2.17 ± 0.01 and bone meal (2.46 ± 0.01. Thus, The sunflower meal and cottonseed meal, on the basis of growth performance and better FCR, can be included in the feed formulation for hybrid fingerlings.

  9. 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...

  10. Life history traits and phenotypic selection among sunflower crop-wild hybrids and their wild counterpart: implications for crop allele introgression.

    Science.gov (United States)

    Kost, Matthew A; Alexander, Helen M; Jason Emry, D; Mercer, Kristin L

    2015-06-01

    Hybridization produces strong evolutionary forces. In hybrid zones, selection can differentially occur on traits and selection intensities may differ among hybrid generations. Understanding these dynamics in crop-wild hybrid zones can clarify crop-like traits likely to introgress into wild populations and the particular hybrid generations through which introgression proceeds. In a field experiment with four crop-wild hybrid Helianthus annuus (sunflower) cross types, we measured growth and life history traits and performed phenotypic selection analysis on early season traits to ascertain the likelihood, and routes, of crop allele introgression into wild sunflower populations. All cross types overwintered, emerged in the spring, and survived until flowering, indicating no early life history barriers to crop allele introgression. While selection indirectly favored earlier seedling emergence and taller early season seedlings, direct selection only favored greater early season leaf length. Further, there was cross type variation in the intensity of selection operating on leaf length. Thus, introgression of multiple early season crop-like traits, due to direct selection for greater early season leaf length, should not be impeded by any cross type and may proceed at different rates among generations. In sum, alleles underlying early season sunflower crop-like traits are likely to introgress into wild sunflower populations.

  11. 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

  12. Species hybridization in the genus Pinus

    Science.gov (United States)

    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...

  13. Fitness of crop-wild hybrid sunflower under competitive conditions: implications for crop-to-wild introgression.

    Science.gov (United States)

    Mercer, Kristin L; Emry, D Jason; Snow, Allison A; Kost, Matthew A; Pace, Brian A; Alexander, Helen M

    2014-01-01

    Understanding the likelihood and extent of introgression of novel alleles in hybrid zones requires comparison of lifetime fitness of parents and hybrid progeny. However, fitness differences among cross types can vary depending on biotic conditions, thereby influencing introgression patterns. Based on past work, we predicted that increased competition would enhance introgression between cultivated and wild sunflower (Helianthus annuus) by reducing fitness advantages of wild plants. To test this prediction, we established a factorial field experiment in Kansas, USA where we monitored the fitness of four cross types (Wild, F1, F2, and BCw hybrids) under different levels of interspecific and intraspecific competition. Intraspecific manipulations consisted both of density of competitors and of frequency of crop-wild hybrids. We recorded emergence of overwintered seeds, survival to reproduction, and numbers of seeds produced per reproductive plant. We also calculated two compound fitness measures: seeds produced per emerged seedling and seeds produced per planted seed. Cross type and intraspecific competition affected emergence and survival to reproduction, respectively. Further, cross type interacted with competitive treatments to influence all other fitness traits. More intense competition treatments, especially related to density of intraspecific competitors, repeatedly reduced the fitness advantage of wild plants when considering seeds produced per reproductive plant and per emerged seedling, and F2 plants often became indistinguishable from the wilds. Wild fitness remained superior when seedling emergence was also considered as part of fitness, but the fitness of F2 hybrids relative to wild plants more than quadrupled with the addition of interspecific competitors and high densities of intraspecific competitors. Meanwhile, contrary to prediction, lower hybrid frequency reduced wild fitness advantage. These results emphasize the importance of taking a full life cycle

  14. Fitness of crop-wild hybrid sunflower under competitive conditions: implications for crop-to-wild introgression.

    Directory of Open Access Journals (Sweden)

    Kristin L Mercer

    Full Text Available Understanding the likelihood and extent of introgression of novel alleles in hybrid zones requires comparison of lifetime fitness of parents and hybrid progeny. However, fitness differences among cross types can vary depending on biotic conditions, thereby influencing introgression patterns. Based on past work, we predicted that increased competition would enhance introgression between cultivated and wild sunflower (Helianthus annuus by reducing fitness advantages of wild plants. To test this prediction, we established a factorial field experiment in Kansas, USA where we monitored the fitness of four cross types (Wild, F1, F2, and BCw hybrids under different levels of interspecific and intraspecific competition. Intraspecific manipulations consisted both of density of competitors and of frequency of crop-wild hybrids. We recorded emergence of overwintered seeds, survival to reproduction, and numbers of seeds produced per reproductive plant. We also calculated two compound fitness measures: seeds produced per emerged seedling and seeds produced per planted seed. Cross type and intraspecific competition affected emergence and survival to reproduction, respectively. Further, cross type interacted with competitive treatments to influence all other fitness traits. More intense competition treatments, especially related to density of intraspecific competitors, repeatedly reduced the fitness advantage of wild plants when considering seeds produced per reproductive plant and per emerged seedling, and F2 plants often became indistinguishable from the wilds. Wild fitness remained superior when seedling emergence was also considered as part of fitness, but the fitness of F2 hybrids relative to wild plants more than quadrupled with the addition of interspecific competitors and high densities of intraspecific competitors. Meanwhile, contrary to prediction, lower hybrid frequency reduced wild fitness advantage. These results emphasize the importance of taking

  15. Effects of different mycorrhiza species on grain yield, nutrient uptake and oil content of sunflower under water stress

    Directory of Open Access Journals (Sweden)

    Mostafa Heidari

    2014-01-01

    Full Text Available The role of arbuscular mycorrhizal fungi in alleviating water stress is well documented. In order to study the effects of water stress and two different mycorrhiza species on grain yield, nutrient uptake and oil content of sunflower, a field experiment as split plot design with three replications was conducted in the Research Field Station, Zabol University, Zabol, Iran in 2011. Water stress treatments included control as 90% of field capacity (W1, 70% field capacity (W2 and 50% field capacity (W3 assigned to the main plots and two different mycorrhiza species, consisting of M1 = control (without any inoculation, M2 = Glumus mossea and M3 = Glumus etanicatum as sub plots. Results showed that by increasing water stress from control (W1 to W3 treatment, grain yield was significantly decreased. The reduction in the level of W3 was 15.05%. The content of potassium in seeds significantly decreased due to water stress but water stress upto W2 treatment increased the content of phosphorus, nitrogen and oil content of seeds. In between two species of mycorrhiza in sunflower plants, Glumus etanicatum had the highest effect on grain yield and these elements in seeds and increased both.

  16. Breeding and High-yield Cultivation Technology of Oil Sunflower Hybrids Longkuiza Series%龙葵杂系列油用向日葵杂交种选育及高产栽培技术

    Institute of Scientific and Technical Information of China (English)

    郭永利

    2013-01-01

    龙葵杂系列油用向日葵杂交种由黑龙江省农科院经济作物研究所育成,龙葵杂6号经全国向日葵鉴定委员会鉴定推广;龙葵杂1~5号和7号经黑龙江省农作物品种审定委员会登记推广。介绍了该系列杂交种的选育及高产栽培技术,为广大葵农在品种选择和栽培技术上提供参考依据。%Oil sunflower hybrids Longkuiza series were bred by Industrial Crops Institute of Heilongjiang Academy of Agricultual Sciences , Longkuiza No.6 was identified and promoted by The National Sunflower Identification Committee ,Longkuiza No.1~5 and No. 7 were registered and promoted by Heilongjiang Provincial Crop Variety Certification Committee. Breeding and high-yield cultivation techniques of Longkuiza series hybrids were described,in order to provide references for many peasants in the selection of species and cultivation technical guidance.

  17. Seed moisture at physiological maturity in oilseed and confectionary sunflower hybrids in the Northern U.S.

    Science.gov (United States)

    Desiccating sunflower (Helianthus annuus L.) to hasten harvest has become a common practice in the northern U.S. and can aid in reducing yield loss associated with severe weather and bird predation. Currently, it is recommended to apply desiccants to sunflower at 35% or less seed moisture correspond...

  18. Breeding of Oil Sunflower Hybrid GE817%油用型向日葵杂交种 GE817的选育

    Institute of Scientific and Technical Information of China (English)

    孟繁明; 李凤学; 辛中宽; 吴艳梅

    2015-01-01

    The oil sunflower hybrid GE817 was bred through hybridization by the Inner Mongolia Ailite Sunflower Seed Co. Ltd. with a process of 5 years. In the Inner Mongolia oil sunflower production test, its seed yield was 3 732 kg/hm 2, in-creasing by 11.72% compared with that of the control S31. In the production, it showed the advantages of strong resistance, wide adaptability and good comprehensive properties. Meanwhile, the GE817 parent breeding and seed production technolo-gies are put forward.%油用向日葵杂交种 GE817是内蒙古金葵艾利特种业公司历经5年时间杂交选育而成。在内蒙古油葵生产试验中籽实产量3732 kg/hm2,较对照 S31增产11.72%,生产中表现出抗逆性强、适应性广、综合性状良好等优点。同时,提出了GE817亲本繁殖及制种技术。

  19. Utilization of sunflower crop wild relatives for cultivated sunflower improvement

    Science.gov (United States)

    Sunflower (Helianthus annuus L.) is one of the few crops native to the U.S. The current USDA-ARS-NPGS crop wild relatives sunflower collection is the largest extant collection in the world, containing 2,519 accessions comprised of 53 species; 39 perennial and 14 annual. To fully utilize gene bank co...

  20. Spectacular Sunflowers

    Science.gov (United States)

    McNeece, Molly

    2010-01-01

    In this article, the author illustrates how she shares her love of sunflowers with her kindergarten and first-grade students through an interesting art lesson. Sunflowers are easy to grow, so the author started the lesson four months earlier with inexpensive seed packets. She planted many varieties, but she most likes the colors of the Mexican…

  1. Sunflower disease compendium: Sunflower botany

    Science.gov (United States)

    The number one challenge for global sunflower production is diseases. Sunflower is the fifth largest oilseed crop grown in temperate and subtropical areas in 72 countries and on every continent, except Antarctica. This has facilitated the spread of diseases globally. Disease control can be by chemic...

  2. RESULTS CONCERNING THE MELLIFEROUS CHARACTERISTICS OF THE SUNFLOWER HYBRIDS CULTIVATED IN ROMANIA

    Directory of Open Access Journals (Sweden)

    NICOLETA ION

    2013-12-01

    Full Text Available The present paper presents the melliferous characteristics of thirty three sunflowerhybrids studied in the period 2002-2006 in South Romania. The studied hybridswere the following: Festiv, Florom 350, Alex, Romina, Performer, Turbo, Favorit,Justin, Splendor, Trajano, Hercule, Felix, Select and 20 being foreign hybrids(Melody, Sunko, Sanay, Kasol, NK Dolbi, NK Ferti, NK Armoni, Opera PR, Rigasol,Huracan, Podium, Fleuret OR, Rigasol, OR, Mateol, Lindor, Fly, Arena, Alexandra,Masai, SaxoIn order to evaluate the quantity of sugar per hectare and further the potential yieldof honey per hectare, the nectar secretion (capillaries method, the sugarconcentration of the nectar (refractometer method, the number of flowers per headand the number of plants per hectare were determined during field studies.

  3. Storage of sunflower seeds

    Directory of Open Access Journals (Sweden)

    Denise de Castro Lima

    Full Text Available The sunflower is among the top five crops in the world for the production of edible vegetable oil. The species displays rustic behavior, with an excellent edaphic and climatic adaptability index, being able to be cultivated throughout Brazil. Seed quality is the key to increasing production and productivity in the sunflower. The objective of this work was to monitor the viability of sunflower seeds with a view to their conservation when stored in different environments and packaging. The seeds were packed in paper bags, multilayered paper, black polyethylene and PET bottles; and stored for a period of twelve months in the following environments: dry cold room (10 ºC and 55% RH, the ambient conditions of Fortaleza, Ceará, Brazil (30-32 ºC and 75% RH, refrigerator (4 ºC and 38-43% RH and freezer (-20 ºC. Every three months, the water content of the seeds was determined and germination, accelerated ageing, speed of emergence index, and seedling dry weight were evaluated. The experimental design was completely randomized, in a scheme of split-lots, with four replications. It can be concluded that the natural environment is not suitable for the storage of sunflower seeds. Sunflower seeds remain viable for 12 months when stored in a dry cold room, refrigerator or freezer, irrespective of the type of packaging used.

  4. Variability in sunflower oil quality for biodiesel production: A simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Pereyra-Irujo, Gustavo A.; Izquierdo, Natalia G.; Quiroz, Facundo; Aguirrezabal, Luis A.N. [Unidad Integrada Balcarce, Facultad de Ciencias Agrarias, Universidad Nacional de Mar del Plata, Instituto Nacional de Tecnologia Agropecuaria, CC 276, 7620 Balcarce, Buenos Aires (Argentina); Covi, Mauro [Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Gueiraldes 2160, Ciudad Universitaria, C1428EGA, Buenos Aires (Argentina); Nolasco, Susana M. [Facultad de Ingenieria, Universidad Nacional del Centro de la Provincia de Buenos Aires, Avda. del Valle 7537, B7400JWI, Olavarria (Argentina)

    2009-03-15

    Biodiesel is an alternative fuel made from vegetable oils or animal fats. The fatty acid composition of the feedstock, which varies among and within species, is the main determinant of biodiesel quality. In this work we analyze the variability in biodiesel quality (density, kinematic viscosity, heating value, cetane number and iodine value) obtained from sunflower oil, by means of a validated crop model that predicts the fatty acid composition of one high-oleic, and three traditional (high-linoleic) sunflower hybrids. The model was run with a 10-year average weather data from 56 weather stations in Argentina, and simulation results were compared to the biodiesel standards of Argentina, USA and Europe. We show that biodiesel produced from sunflower oil does not have one fixed quality, but different qualities depending on weather conditions and agricultural practices, and that intraspecific variation in biodiesel quality can be larger than interspecific differences. Our results suggest that (a) sunflower oil from high-oleic hybrids is suitable for biodiesel production (within limits of all analyzed standards), regardless of growing conditions and (b) sunflower oil from traditional hybrids is suitable for biodiesel production under the standards of Argentina and USA, while only certain hybrids grown in warm regions (e.g., Northern Argentina, Southern USA, China, India, Pakistan) are suitable for biodiesel production according to the European standard. (author)

  5. Extracting female inbred lines from commercial sunflower hybrids Extração de linhagens fêmeas a partir de híbridos comerciais de girassol

    Directory of Open Access Journals (Sweden)

    Claudio Guilherme Portela de Carvalho

    2008-09-01

    Full Text Available The objective of this study was to obtain female inbred lines from sunflower (Helianthus annuus hybrids. A methodology based on altering inbred lines carrying the fertility restorer gene (Rf obtained from self pollinating hybrids into inbred lines with normal cytoplasm without the Rf gene was described. Further, derived male-sterile inbred lines were developed. The methodology was successfully used to obtain female inbreds from sunflower commercial hybrids. Although more time and labor consuming than the conventional female inbred line extraction methods, this methodology is advantageous in exploiting superior germplasms (commercial hybrids, which prompted us to develop practical procedures to allow its routinely use.O objetivo desse trabalho foi obter linhagens fêmeas a partir de híbridos de girassol (Helianthus annuus. A metodologia foi descrita com base na alteração de linhagens com o gene restaurador de fertilidade (Rf, obtidas da auto-fecundação dos híbridos, em linhagens com citoplasma normal e sem o gene Rf. Em seguida, linhagens macho-estéreis foram desenvolvidas. Com o uso dessa metodologia foi possível obter linhagens fêmeas, a partir de híbridos comerciais de girassol. Apesar de essa requerer maior tempo e mão-de-obra do que o procedimento usual de obtenção de linhagens fêmeas, essa metodologia tem a vantagem de propiciar a exploração de germoplasmas superiores (híbridos comerciais, o que estimulou a descrição de procedimentos que permitam tornar a metodologia mais rotineira.

  6. Relative susceptibility of sunflower maintainer lines and resistance sources to natural infestations of the banded sunflower moth (Lepidoptera: Tortricidae)

    Science.gov (United States)

    The banded sunflower moth, Cochylis hospes Walsingham (Lepidoptera: Tortricidae), is a significant seed-feeding pest of sunflowers in North America. Though some wild Helianthus spp., interspecific crosses, and H. annuus cultivars (that precede hybrid sunflower breeding) have low susceptibility to ba...

  7. Improvement of sunflower for consumption

    Directory of Open Access Journals (Sweden)

    Dijanović Dijana

    2003-01-01

    Full Text Available Growing sunflower (Heliianthus annuus L for consumption is becoming more and more attractive in the whole world and in our country, as well. The consumption of this product has been considerably increased because it is being used more and more in various forms: sunflower seed in a hull, hulled kernels fried or non-fried, salted or non-salted with addition of various spices. The sunflower kernel is used for preparing over 100 different food products: special types of bread, cakes, ice-cream, chocolate. In accordance with the trade demands, the aims of sunflower seeds for consumption improvement are: high productivity, greater content of proteins, lesser content of oil, oncreased mass of 1000 seeds, lesser portion of the hull easy nibbling, as well as tolerance to dominant diseases in the growing region. In the Agricultural and Technological Research Center in Zajecar, 4 genotypes of protein sunflower (two cultivars and two hybrids have been created so far. This study shows the results achieved in increasing the content of protein, the mass of 1000 seeds, decreasing the content of oil and hull of the new 90 hybrid combination. The hybrid combinations were obtained by crossing of the CMS and restorer lines.

  8. The catalytic properties of hybrid Rubisco comprising tobacco small and sunflower large subunits mirror the kinetically equivalent source Rubiscos and can support tobacco growth.

    Science.gov (United States)

    Sharwood, Robert Edward; von Caemmerer, Susanne; Maliga, Pal; Whitney, Spencer Michael

    2008-01-01

    Plastomic replacement of the tobacco (Nicotiana tabacum) Rubisco large subunit gene (rbcL) with that from sunflower (Helianthus annuus; rbcL(S)) produced tobacco(Rst) transformants that produced a hybrid Rubisco consisting of sunflower large and tobacco small subunits (L(s)S(t)). The tobacco(Rst) plants required CO(2) (0.5% v/v) supplementation to grow autotrophically from seed despite the substrate saturated carboxylation rate, K(m), for CO(2) and CO(2)/O(2) selectivity of the L(s)S(t) enzyme mirroring the kinetically equivalent tobacco and sunflower Rubiscos. Consequently, at the onset of exponential growth when the source strength and leaf L(s)S(t) content were sufficient, tobacco(Rst) plants grew to maturity without CO(2) supplementation. When grown under a high pCO(2), the tobacco(Rst) seedlings grew slower than tobacco and exhibited unique growth phenotypes: Juvenile plants formed clusters of 10 to 20 structurally simple oblanceolate leaves, developed multiple apical meristems, and the mature leaves displayed marginal curling and dimpling. Depending on developmental stage, the L(s)S(t) content in tobacco(Rst) leaves was 4- to 7-fold less than tobacco, and gas exchange coupled with chlorophyll fluorescence showed that at 2 mbar pCO(2) and growth illumination CO(2) assimilation in mature tobacco(Rst) leaves remained limited by Rubisco activity and its rate (approximately 11 micromol m(-2) s(-1)) was half that of tobacco controls. (35)S-methionine labeling showed the stability of assembled L(s)S(t) was similar to tobacco Rubisco and measurements of light transient CO(2) assimilation rates showed L(s)S(t) was adequately regulated by tobacco Rubisco activase. We conclude limitations to tobacco(Rst) growth primarily stem from reduced rbcL(S) mRNA levels and the translation and/or assembly of sunflower large with the tobacco small subunits that restricted L(s)S(t) synthesis.

  9. 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

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

    Science.gov (United States)

    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

  11. 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...

  12. 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.

  13. Sunflower (Helianthus annuus L.).

    Science.gov (United States)

    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. [Possible uses of sunflower in proper human nutrition].

    Science.gov (United States)

    Skorić, Dragan

    2009-01-01

    The sunflower is the main oil crop in Serbia and one of the four major oil crops on the global scale. The seed of commercial sunflower crops being grown today consists most commonly of 45-53% oil and 15-18% protein. Unfortunately, sunflower seed protein has traditionally been underused in the human diet in Serbia. The amino acid composition of sunflower protein is quite favorable. In addition to oil and protein, sunflower kernels contain tocopherols, minerals, and vitamins. The sunflower is also a major honey plant, as sunflower plants produce over 40 kg of nectar and over 80 kg of pollen per area unit (hectare) under normal circumstances. Standard sunflower oil is linoleic in character, but induced mutations have been used to obtain genotypes with a high-oleic acid content of the oil (> 85%), thus enabling the development of high-oleic sunflower hybrids. Induced mutations have also been used to obtain genotypes with high levels of palmitic, stearic, and linoleic acids. The predominant tocopherol in standard sunflower oil is the alpha one, but sunflower genotypes have now been developed using spontaneous and induced mutations that predominantly contain beta, gamma, and delta tocopherols. Various developments in the field of genetics have made it possible to develop sunflower hybrids with different oil profiles in terms of fatty acid composition and tocopherol type and amount. The thermo-oxidative stability of the new types of sunflower oil is significantly higher than that of standard sunflower oil. Of the new types of sunflower, it is the high-oleic hybrids that have found the widest application in commercial production. It is expected that the future sunflower hybrids combining high levels of oleic and stearic acids with gamma tocopherol will become a major component of a healthy human diet. The development of new consumption sunflower hybrids with an increased protein content and altered oil quality will lead to the development of a large number of novel final

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

    Science.gov (United States)

    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.

  16. DEVELOPMENT OF CODOMINANT MARKERS FOR IDENTIFYING SPECIES HYBRIDS

    Science.gov (United States)

    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...

  17. 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.

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

    Science.gov (United States)

    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.

  19. 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.

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

    Science.gov (United States)

    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.

  1. 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....

  2. 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.

  3. Comparative study of physiological parameter and grain yield on different sunflower hybrid populations%不同向日葵品种群体光合生理参数及产量比较

    Institute of Scientific and Technical Information of China (English)

    崔良基; 王德兴; 宋殿秀; 孙恩玉; 刘金刚

    2011-01-01

    Field experiment was conducted to study the physiological parameter and grain yield on 3 sunflower hybrid populations. Result showed that leaf area index were developed very fast. The time of the max leaf area index were at 51 d after seedling emergence. The leaf area index varied with different sunflower hybrids with a range of 3.57 ~ 5.64. Biological yield and grain yield had significant positive correlation with the photosynthesis potential of the population. The average net photosynthetic rates were 5.08 to 7.02g/m2 · d, and varied with different sunflower hybrids and years. The trends of biological yield accumulation were "fast - slow - fast", and conformed to the Logistic equation model. Distribution ratio of biomass in various organs was stem (grain) > grain (stem) > leaf >head > petiole. The average percentages of grain ( economical index) were 29.7% and 34.4% in two years. The economical index of early maturity sunflower was higher than that of middle maturity sunflower.%以3个向日葵品种为材料,通过两年的田间试验研究向日葵群体的光合生理特征.结果表明,向日葵群体的叶面积指数(LAI)增长极快,出苗后第51d前后即达到最大值(LAImax)3.57~5.64.群体光合势与生物产量和子实产量呈极显著正相关.平均净光合率因品种和年份而异,范围在5.08~7.02g/m2·d.生物产量积累动态趋势为"慢-快-慢",符合Logistic方程.生物产量在各个器官中的分配比例一般为:茎秆(或子实)>子实(或茎秆)>叶片>葵盘>叶柄,子实所占比例即经济系数两年平均为29.7%和34.4%,因年份而异.早熟品种的经济系数大于中早熟和中熟品种.

  4. Effect of cultivation measures on index of photosynthesis and yield of sunflower

    OpenAIRE

    Aksyonov I.

    2007-01-01

    Photosynthetic activity is the decisive factor of yield increase in sunflower plants. This activity determines the application of agrotechnical measures such as row spacing and plant density. Experiments have proved that agrotechnical measures allow to control the growth, development and yield of sunflower hybrids and varieties. Row spacing and plants density affect the index of photosynthesis and the yield of sunflower agrophytocoenoses. Cultivation of sunflower at the row spacing of 15 cm i...

  5. 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.

  6. Van Gogh's Sunflowers

    Science.gov (United States)

    Daddino, Michelle

    2010-01-01

    In this article, the author describes an art project wherein kindergarten students painted sunflowers. These beautiful and colorful sunflowers were inspired by the book "Camille and the Sunflowers" by Laurence Anholt, which does an amazing job of introducing young children to the art and life of Vincent van Gogh.

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

    Science.gov (United States)

    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.

  8. 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

  9. 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

  10. 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...

  11. 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

  12. 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.

  13. 青岛地区国外油葵杂交种夏播比较试验%Contrast Test of Oil Sunflower Hybrids Introduced from Foreign Sown in Summer in Qingdao Areas

    Institute of Scientific and Technical Information of China (English)

    王瑞英; 黄婷婷; 刘炳禄; 盖红梅; 刘淑芹

    2011-01-01

    以澳大利亚油葵杂交种S31为对照,种植观察引自西班牙、印度的9个油葵杂交种的生育期、田间生育性状、产量及葵花籽性状.结果表明,引自印度的Surx Kiran与surgaKiran具有较高的葵花籽与籽仁产量,并且具有较好的田间表现与较短的生育期,因而可以在青岛地区夏播条件下进一步示范种植.%With S31, an oil sunflower hybrid introduced from Australia as the control, 9 oil sunflower hybrids from Spain and India were sown in summer to study the growth period, growth character in field, yield and achene character. The results showed that Surx Kiran and Surga Kiran introduced from India had higher a-chene and kernel yields, better field performance and shorter growth period. So they were suitable to sown in summer in Qingdao areas.

  14. 氮、磷、钾配施对油葵杂交种群体总光合势的影响%Impact of Nitrogen, Phosphorus and Potassium Fertilizer on Gross Photosynthetic Potential of Oil Sunflower Hybrid Groups

    Institute of Scientific and Technical Information of China (English)

    董宁

    2013-01-01

    采用“3414”最优饱和设计方案,于2010年在辽宁省农科院试验田以氮(N)、磷(P2O5)、钾(K2O)肥为研究因素进行田间试验。探讨氮、磷、钾3个因素对油葵杂交种F60总光合势的影响。经分析发现,施入不同配比的氮、磷、钾肥,能显著提高油葵群体的总光合势。%The "3414" optimum design scheme was adopted to conduct filed experiemtn in 2010 by Liaoning Academy of Agricultural Sciences to study the impact of Nitrogen, Phosphorus and Potassium Fertilizer on gross photosynthetic potential of oil sunflower hybrid groups. The analysis shows that the different ratio of nitrogen, phosphorus, potassium can significantly improve the gross photosynthetic potential of oil sunflower hybrid groups.

  15. 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)

    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 a 20% yield advantage over the open-pollinated varieties. However, sunflower production in Nor...

  16. 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.

  17. The repetitive component of the sunflower genome

    Directory of Open Access Journals (Sweden)

    T. Giordani

    2014-08-01

    Full Text Available The sunflower (Helianthus annuus and species belonging to the genus Helianthus are emerging as a model species and genus for a number of studies on genome evolution. In this review, we report on the repetitive component of the H. annuus genome at the biochemical, molecular, cytological, and genomic levels. Recent work on sunflower genome composition is described, with emphasis on different types of repeat sequences, especially LTR-retrotransposons, of which we report on isolation, characterisation, cytological localisation, transcription, dynamics of proliferation, and comparative analyses within the genus Helianthus.

  18. Density Distribution Sunflower Plots

    Directory of Open Access Journals (Sweden)

    William D. Dupont

    2003-01-01

    Full Text Available Density distribution sunflower plots are used to display high-density bivariate data. They are useful for data where a conventional scatter plot is difficult to read due to overstriking of the plot symbol. The x-y plane is subdivided into a lattice of regular hexagonal bins of width w specified by the user. The user also specifies the values of l, d, and k that affect the plot as follows. Individual observations are plotted when there are less than l observations per bin as in a conventional scatter plot. Each bin with from l to d observations contains a light sunflower. Other bins contain a dark sunflower. In a light sunflower each petal represents one observation. In a dark sunflower, each petal represents k observations. (A dark sunflower with p petals represents between /2-pk k and /2+pk k observations. The user can control the sizes and colors of the sunflowers. By selecting appropriate colors and sizes for the light and dark sunflowers, plots can be obtained that give both the overall sense of the data density distribution as well as the number of data points in any given region. The use of this graphic is illustrated with data from the Framingham Heart Study. A documented Stata program, called sunflower, is available to draw these graphs. It can be downloaded from the Statistical Software Components archive at http://ideas.repec.org/c/boc/bocode/s430201.html . (Journal of Statistical Software 2003; 8 (3: 1-5. Posted at http://www.jstatsoft.org/index.php?vol=8 .

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

    Directory of Open Access Journals (Sweden)

    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

  20. Silky Sunflowers & Swirly Skies

    Science.gov (United States)

    Welling, Linda

    2012-01-01

    In this article, second-graders create a sunflower drawing using pastel techniques that produce similar effects to Vincent van Gogh's brushstrokes. They also learn how layering colors and using white to lighten colors creates depth in their flowers.

  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. Significance of cytogenetic research in sunflower and rapeseed breeding

    National Research Council Canada - National Science Library

    Atlagić Jovanka; Terzić Sreten; Marjanović-Jeromela Ana; Marinković Radovan

    2010-01-01

    Cytogenetic research of sunflower and rapeseed has a century long tradition. Chromosome number and morphology were studied at first in species from the Helianthus and Brassica genera, and than their cytotaxonomy and phylogenesis...

  3. Sunflower crop in Argentina to date

    OpenAIRE

    Vasquez A.; de Romano A.

    2006-01-01

    Inside a panorama of a spectacular grain production in the last 10 years in Argentina, sunflower crop participates with an annual production of more than 3,500,000 t. During that period, many advances were made in the improvement of diseases resistance: Verticillium wilt, downy mildew and head rot. Also oil yield per hectare continued to increase. The new hybrids have new qualities, for example imidazolinones resistance, which allows farmers to keep yields, although the soils destined to sunf...

  4. [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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Sunflower stem weevil and its larval parasitoids in native sunflowers: is parasitoid abundance and diversity greater in the U.S. Southwest?

    Science.gov (United States)

    Ode, Paul J; Charlet, Laurence D; Seiler, Gerald J

    2011-02-01

    Classical biological control programs often target a pest's region of origin as a likely source for new biological control agents. Here, we use this approach to search for biological control agents of the sunflower stem weevil (Cylindrocopturus adspersus LeConte), an economically important pest of commercial sunflower. We conducted surveys of weevil natural enemy diversity and abundance across a transect running from the northern Great Plains to the southwestern U.S. (the presumed area of endemism of annual sunflower species in the genus Helianthus). Accordingly, natural enemy diversity and abundance were expected to be greater in the southwestern U.S. C. adspersus and their larval parasitoids were collected from stems of four native sunflower species (Helianthus annuus, H. nuttallii, H. pauciflorus, and H. petiolaris) from 147 sites across eight states. Native H. annuus constituted the majority of the sunflower populations. Mean weevil densities were significantly higher in sunflower stalks that were larger in diameter. Mean weevil densities within sites did not differ across the range of longitudes and latitudes sampled. After accounting for the effects of stalk diameter and location, weevil densities did not differ among the four sunflower species nor did they differ as a function of elevation. C. adspersus in H. annuus and H. petiolaris were attacked by seven species of parasitoids. No parasitoids were found attacking C. adspersus in H. nuttallii or H. pauciflorus stalks. C. adspersus were twice as likely to be attacked by a parasitoid when feeding on H. petiolaris than H. annuus. Furthermore, the likelihood that C. adspersus would be parasitized decreased with increasing elevation and increasing stem diameters. All parasitoid species have been previously reported attacking C. adspersus larvae in cultivated sunflower. Species richness was less diverse in these collections than from previous studies of cultivated sunflower. Our findings suggest that the species

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  14. 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.

  15. 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.

  16. MICROELEMENTS IN SUNFLOWER CROPS

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    Buldykova I. A.

    2015-03-01

    Full Text Available The obtained experimental data show that the incorporation of trace elements into the system of the sunflower crop has a positive impact on the mineral nutrition of plants, the number and quality of the crop. Foliar feeding of sunflower crops with micronutrients improves nutrition of plants with nitrogen, phosphorus and potassium, thus creating the preconditions for the formation of highly agrocenosis. The seed yield of sunflower increased by variants with application of micronutrients 1.2-3.5 t/ha or 4.4-12.9 percent. The greatest impact of treatment with boron and copper, exceeding the background option 3.1-3.5 t/ha or 11.5-12.9% respectively. The crop is least influenced by manganese and molybdenum. The examined elements positively influenced the structure of the sunflower crop. The greatest influence on the diameter of the basket, the number of seeds, weight of seeds in the basket, the weight of 1000 seeds was provided by the zinc and copper. Trace elements contributed to the improvement of quality indicators of sunflower. For husk content, the greatest positive effect was cobalt, zinc, manganese and copper, increasing the background option 10.1, 10.4, 10.5 and 10, and 6%, respectively, on the oil content of sunflower seeds had cobalt, copper and zinc. The oil content on these options amounted 55,0, with 55.1 and 55.2%, respectively, increasing this figure by 1.5 to 1.7 %. The acid number at variants with boron, manganese and zinc was the same with the background option and amounted to 1.8. The greatest influence on iodine number provided molybdenum, zinc and copper, which accounted for 170,5, 171,2 and 171,4, exceeding the background option 10.2 and 11.1

  17. 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

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

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    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

  19. A crop model-based approach for sunflower yields

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    João Guilherme Dal Belo Leite

    2014-10-01

    Full Text Available Pushed by the Brazilian biodiesel policy, sunflower (Helianthus annuus L. production is becoming increasingly regarded as an option to boost farmers' income, particularly under semi-arid conditions. Biodiesel related opportunities increase the demand for decision-making information at different levels, which could be met by simulation models. This study aimed to evaluate the performance of the crop model OILCROP-SUN to simulate sunflower development and growth under Brazilian conditions and to explore sunflower water- and nitrogen-limited, water-limited and potential yield and yield variability over an array of sowing dates in the northern region of the state of Minas Gerais, Brazil. For model calibration, an experiment was conducted in which two sunflower genotypes (H358 and E122 were cultivated in a clayey soil. Growth components (leaf area index, above ground biomass, grain yield and development stages (crop phenology were measured. A database composed of 27 sunflower experiments from five Brazilian regions was used for model evaluation. The spatial yield distribution of sunflower was mapped using ordinary kriging in ArcGIS. The model simulated sunflower grain productivity satisfactorily (Root Mean Square Error ≈ 13 %. Simulated yields were relatively high (1,750 to 4,250 kg ha-1 and the sowing window was fairly wide (Oct to Feb for northwestern locations, where sunflower could be cultivated as a second crop (double cropping at the end of the rainy season. The hybrid H358 had higher yields for all simulated sowing dates, growth conditions and selected locations.

  20. Sowing quality of seeds sunflower, depending on the influence of plant growth regulators and protectants

    OpenAIRE

    Буряк, Ю. І.; Огурцов, Ю. Є.; Чернобаб, О. В.; Клименко, І. І.

    2014-01-01

    Aim. The aim of this work was to study the influence of plant growth regulators and protectants on the sowing quality of seeds parental forms and hybrids of sunflower.Methodology and materials. Research conducted in the Plant Production Institute named after V.Ya. Yuriev NAAS. The predecessor of sunflower – winter wheat. Sunflower seeds parent lines Сх1010А, Х720В, Х526В and hybrids F1 Romance and Maximus were sown in optimal terms with the seeding norm of 57 thousand pieces of viable seeds p...

  1. 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.

  2. 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.

  3. 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.

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

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    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.

  5. Avaliação de híbridos de girassol e relação entre parâmetros produtivos e qualitativos Evaluation of sunflower hybrids and the relationship between productive and qualitative parameters

    Directory of Open Access Journals (Sweden)

    Laerte Gustavo Pivetta

    2012-09-01

    Full Text Available O presente estudo teve o objetivo de determinar genótipos superiores de girassol, bem como realizar estudos de correlação entre suas características. Avaliou-se seis híbridos de girassol em condições de safrinha no município de Palotina - PR. O estudo avaliou quinze variáveis: massa seca de folhas, massa seca de caule e pecíolos, massa seca total, área foliar, altura de planta, diâmetro de colmo, massa de grãos por capítulo, diâmetro de capítulo, percentagem de grãos normais, massa de mil grãos, número de grãos por capítulo, produtividade, teor de proteína bruta, teor de óleo e rendimento de óleo. Os dados direcionam os híbridos H360 e MG2 com boa produtividade e maior teor de óleo para a produção de óleo e os híbridos M734 e Aguará 3 para a alimentação animal, com boa produtividade e menor teor de óleo. As correlações entre produtividade e os componentes de produção foram de 0,62; 0,47; 0,60; 0,49 e 0,47 para massa de grãos por capítulo, diâmetro de capítulo, percentagem de grãos normais, massa de mil grãos e número de grãos por capítulo, respectivamente, concluindo que a seleção de materiais a partir desses componentes ocasionará a seleção de materiais promissores em produtividade.The objective of this work was to determine superior genotypes of the sunflower, as well as to study the correlation between its characteristics. Six sunflower hybrids were evaluated under late-summer conditions in Palotina in the state of Paraná. The study evaluated fifteen variables: leaf dry mass, stem and petiole dry mass, total dry mass, leaf area, plant height, stem diameter, grain weight per head, head diameter, percentage of normal grains, thousand grain weight, number of grains per head, productivity, crude protein content, oil content and oil yield. According to the data, the hybrids H360 and MG2, with good productivity and higher oil content, are indicated for oil production, and the hybrids M734 and

  6. Dragee product based on sunflower

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    Pajin Biljana S.

    2003-01-01

    Full Text Available The sunflower kernel is rich in valuable nutritive compounds so it is suitable as a raw material for production of confectionery products. In this paper we evaluated the technological characteristics of the confectionery sunflower kernel with the aim of obtaining dragee products, and determining the final product quality and shelf life. The dragee product was obtained by panning sunflower kernel with savory powder mixture of spices in a dragee pan. The used sunflower seed has an even distribution of linear size and satisfactory dehulling characteristics. The savoury dragee product was in excellent category of sensory quality and showed stable colour and good shelf life in the period of three months.

  7. 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.

  8. Crop-weed competition between sunflower (Helianthus annuus L.) and Convolvulus arvensis L. in substitutive experiments.

    Science.gov (United States)

    Kazinczi, G; Takács, A; Horváth, J

    2006-01-01

    The main characteristics of a substitutive experiment is that the proportions of two species in the mixtures are varied while the overall density of the two species is maintained constant - a replacement series. In our experiments early competition between sunflower and field bindweed (Convolvulus arvensis) was studied in a replacement studies under glasshouse conditions. Pot experiments were set up with the following treatments: 1, sunflower 100% (6 plants pot(-1)); 2, sunflower 66.6% (4 plants pot(-1)) + C. arvensis 33.3% (2 plants pot(-1)); 3, sunflower 33.3% (2 plants pot(-1)) + C. arvensis 66.6% (4 plants pot(-1)); 4, C. arvensis 100% (6 plants pot(-1)). Sixty eight days after sowing dry weight of shoots and roots were measured and nitrogen (N), phosphorus (P) and potassium (K) content was also determined. Dry biomass production of sunflower was almost twice higher as compared to that of C. arvensis without interspecific competition. Dry weight of sunflower and C. arvensis shoots and roots for a plant continuously decreased by reducing their proportion in the mixtures. Higher biomass production of sunflower suggests, that its development is faster at the beginning of vegetation penod, therefore sunflower has better competitive ability in sunflower--C. arvensis mixtures in the early competition as compared to C. arvensis. Shoot:root ratio of plants did not change considerably in mixtures, but generally was ten times higher in sunflower plants, as compared to that of C. arvensis. Shoots generally contained macro elements at higher concentration as compared to those of roots. Total NPK content of sunflower was reduced by 53 and 82% for a pot, as its proportion decreased in the mixtures. More severe reduction in NPK content was observed in case of C. arvensis, which also proves stronger competitive ability of sunflower in the early vegetation.

  9. 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.

  10. 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

  11. 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.

  12. Gustav klimt's "sunflower" impact on Schiller "sunflower" Ⅱ

    Institute of Scientific and Technical Information of China (English)

    陈凯新

    2016-01-01

    gustav klimt and Schiller as a master of expressionism, same to the entire world's art has a great influence. But klimt's landscape painting had a huge impact on Schiller's landscape paintings, the most typical example is Schiller's already watched the klimt's "sunflower"exhibition, to create a picture composition and theme is very similar to the sunflower Ⅱ, thus klimt for Schiller's influence.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Density Distribution Sunflower Plots

    OpenAIRE

    Dupont, William D; W. Dale Plummer Jr.

    2003-01-01

    Density distribution sunflower plots are used to display high-density bivariate data. They are useful for data where a conventional scatter plot is difficult to read due to overstriking of the plot symbol. The x-y plane is subdivided into a lattice of regular hexagonal bins of width w specified by the user. The user also specifies the values of l, d, and k that affect the plot as follows. Individual observations are plotted when there are less than l observations per bin as in a conventio...

  8. Methods for assessing infestations of sunflower stem weevil (Coleoptera: Curculionidae) in sunflower stems

    Science.gov (United States)

    The sunflower stem weevil, Cylindrocopturus adspersus LeConte (Coleoptera: Curculionidae), reduces sunflower, Helianthus annuus L. (Asteraceae), yields by spreading pathogens, damaging vascular tissues, and promoting lodging of sunflower plants. To assess weevil populations for host plant resistanc...

  9. EFFECTS OF ROW SPACING ON AGRONOMIC CHARACTERS OF THREE DOUBLE CROPPED SUNFLOWER HYBRIDS EFEITOS DO ESPAÇAMENTO ENTRE LINHAS NOS CARACTERES AGRONÔMICOS DE TRÊS HÍBRIDOS DE GIRASSOL CULTIVADOS NA SAFRINHA

    Directory of Open Access Journals (Sweden)

    Ana Cláudia Barneche de Oliveira

    2009-03-01

    Full Text Available

    The objective of the research was to evaluate the effects of row spacing on agronomic characteristics of three sunflower hybrids. The trial was carried out in Rio Verde, Goiás State, Brazil. The hybrids tested were Agrobel 960, BRHS 5, and Hélio 251, in four row spacing (40 cm, 50 cm, 70 cm, and 80 cm, in a population of 45.000 plants ha-1. The hybrids were planted in March 12, 2005, after bean grown in the summer season, and harvested in July 5. Achene yield and thousand weight, capitulum size, number of achenes per capitulum, and plant height were evaluated. The Agrobel 960 hybrid presented the largest achene yield and the smallest height. The larger yield of Agrobel 960 was attributed to the higher number of achenes per capitulum. The sunflower hybrids did not present significant differences for achene thousand weight and capitulum size. The 40 cm row spacing presented larger achene yield and number of achenes per capitulum. However, it did not influence the achene thousand weight, capitulum size, and plant height.

     

    KEY-WORDS: Helianthus annuus

  10. 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.

  11. 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.

  12. Genome scans reveal candidate domestication and improvement genes in cultivated sunflower, as well as post-domestication introgression with wild relatives.

    Science.gov (United States)

    Baute, Gregory J; Kane, Nolan C; Grassa, Christopher J; Lai, Zhao; Rieseberg, Loren H

    2015-04-01

    The development of modern crops typically involves both selection and hybridization, but to date most studies have focused on the former. In the present study, we explore how both processes, and their interactions, have molded the genome of the cultivated sunflower (Helianthus annuus), a globally important oilseed. To identify genes targeted by selection during the domestication and improvement of sunflower, and to detect post-domestication hybridization with wild species, we analyzed transcriptome sequences of 80 genotypes, including wild, landrace, and modern lines of H. annuus, as well as two cross-compatible wild relatives, Helianthus argophyllus and Helianthus petiolaris. Outlier analyses identified 122 and 15 candidate genes associated with domestication and improvement, respectively. As in several previous studies, genes putatively involved in oil biosynthesis were the most extreme outliers. Additionally, several promising associations were observed with previously mapped quantitative trait loci (QTLs), such as branching. Admixture analyses revealed that all the modern cultivar genomes we examined contained one or more introgressions from wild populations, with every chromosome having evidence of introgression in at least one modern line. Cumulatively, introgressions cover c. 10% of the cultivated sunflower genome. Surprisingly, introgressions do not avoid candidate domestication genes, probably because of the reintroduction of branching.

  13. 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.

  14. 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.

  15. Pollen production in sunflower (Helianthus annuus L.) is affected by air temperature and relative humidity during early reproductive growth

    OpenAIRE

    Astiz, V.; Hernández, Luis Francisco

    2013-01-01

    During microsporogenesis, sunflower florets might be exposed to episodes of day- and night-time temperatures exceeding 30 and 20 °C, respectively, that can affect pollen availability and consequently plant’s yield. The relationship between air temperature and relative humidity during the meiotic phase of microsporogenesis, and the quantity and quality of pollen produced by the flowers, were studied in two sunflower hybrids during two years. The hybrids were grown on irrigated plots in Bahía B...

  16. 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...

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. The Population Genomics of Sunflowers and Genomic Determinants of Protein Evolution Revealed by RNAseq

    Directory of Open Access Journals (Sweden)

    Loren H. Rieseberg

    2012-10-01

    Full Text Available Few studies have investigated the causes of evolutionary rate variation among plant nuclear genes, especially in recently diverged species still capable of hybridizing in the wild. The recent advent of Next Generation Sequencing (NGS permits investigation of genome wide rates of protein evolution and the role of selection in generating and maintaining divergence. Here, we use individual whole-transcriptome sequencing (RNAseq to refine our understanding of the population genomics of wild species of sunflowers (Helianthus spp. and the factors that affect rates of protein evolution. We aligned 35 GB of transcriptome sequencing data and identified 433,257 polymorphic sites (SNPs in a reference transcriptome comprising 16,312 genes. Using SNP markers, we identified strong population clustering largely corresponding to the three species analyzed here (Helianthus annuus, H. petiolaris, H. debilis, with one distinct early generation hybrid. Then, we calculated the proportions of adaptive substitution fixed by selection (alpha and identified gene ontology categories with elevated values of alpha. The “response to biotic stimulus” category had the highest mean alpha across the three interspecific comparisons, implying that natural selection imposed by other organisms plays an important role in driving protein evolution in wild sunflowers. Finally, we examined the relationship between protein evolution (dN/dS ratio and several genomic factors predicted to co-vary with protein evolution (gene expression level, divergence and specificity, genetic divergence [FST], and nucleotide diversity pi. We find that variation in rates of protein divergence was correlated with gene expression level and specificity, consistent with results from a broad range of taxa and timescales. This would in turn imply that these factors govern protein evolution both at a microevolutionary and macroevolutionary timescale. Our results contribute to a general understanding of the

  4. The Population Genomics of Sunflowers and Genomic Determinants of Protein Evolution Revealed by RNAseq.

    Science.gov (United States)

    Renaut, Sébastien; Grassa, Christopher J; Moyers, Brook T; Kane, Nolan C; Rieseberg, Loren H

    2012-10-25

    Few studies have investigated the causes of evolutionary rate variation among plant nuclear genes, especially in recently diverged species still capable of hybridizing in the wild. The recent advent of Next Generation Sequencing (NGS) permits investigation of genome wide rates of protein evolution and the role of selection in generating and maintaining divergence. Here, we use individual whole-transcriptome sequencing (RNAseq) to refine our understanding of the population genomics of wild species of sunflowers (Helianthus spp.) and the factors that affect rates of protein evolution. We aligned 35 GB of transcriptome sequencing data and identified 433,257 polymorphic sites (SNPs) in a reference transcriptome comprising 16,312 genes. Using SNP markers, we identified strong population clustering largely corresponding to the three species analyzed here (Helianthus annuus, H. petiolaris, H. debilis), with one distinct early generation hybrid. Then, we calculated the proportions of adaptive substitution fixed by selection (alpha) and identified gene ontology categories with elevated values of alpha. The "response to biotic stimulus" category had the highest mean alpha across the three interspecific comparisons, implying that natural selection imposed by other organisms plays an important role in driving protein evolution in wild sunflowers. Finally, we examined the relationship between protein evolution (dN/dS ratio) and several genomic factors predicted to co-vary with protein evolution (gene expression level, divergence and specificity, genetic divergence [FST], and nucleotide diversity pi). We find that variation in rates of protein divergence was correlated with gene expression level and specificity, consistent with results from a broad range of taxa and timescales. This would in turn imply that these factors govern protein evolution both at a microevolutionary and macroevolutionary timescale. Our results contribute to a general understanding of the determinants of

  5. 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.

  6. Preventing Rancidity in sunflower Oil

    African Journals Online (AJOL)

    used in turn to extract the polar flavonoids, while chilled acetone and petroleum ether ... sunflower oil was measured using changes in peroxide values and the UV absorbances (Conjugated diene) .... metal ions and metalloprotein catalysts.

  7. 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.

  8. Sunflower Seed and Acne Vulgaris.

    Science.gov (United States)

    Mohebbipour, Alireza; Sadeghi-Bazargani, Homayoun; Mansouri, Mona

    2015-09-01

    Regardless of the overall association between diet and acne which cannot be easily ignored, there might be an association between specific nutrients and acne development or improvement. The aim of this study was to assess the effect of dietary intake of sunflower seeds on acne severity and the pattern of acne lesions. In a randomized controlled trial, 50 patients aged 15 - 30 years old with acne vulgaris were enrolled through consecutive convenient sampling, in a dermatology clinic in Ardabil, Iran. They were randomly allocated into two trial arms. Those in the control group were asked to stop eating sunflower seeds if they did before. In the intervention group, they consumed 25 g sunflower-containing food daily for seven days. The primary outcome of interest was 10% increase/decrease in the baseline acne severity index (ASI), sustained to the end of the follow-up period on day 14. The mean ASI did not change significantly through the study period in the control group, but it increased in the sunflower group from 62 at the baseline to 86.8 after two weeks (P acne grading score (GAGS) did not significantly change in any of the groups and the difference in the change of GAGS was not significant between the groups (2.4 in the sunflower group versus 1.6 in the control group). Twenty two subjects (88%) in the sunflower group versus 9 (36%) in the control group had at least 10% increment in ASI throughout the follow-up period (P acne vulgaris; however, further evidence is needed to ban sunflower seed intake in patients with acne. Considering the observed potential negative effect in this trial, future randomized clinical trials may base their design on randomly assigning the exposed patients to give up use of sunflower seed intake.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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).

  14. 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...

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. Mycoflora of phylloplane as a factor protecting the oil sunflower against the diseases caused by fungi, depending on ecological conditions

    Directory of Open Access Journals (Sweden)

    Włodzimierz Kita

    2014-08-01

    Full Text Available In the years 1980-83 a research was carried out on the phylloplane of oil sunflowers. A composition of species of the fungus community was determined as well as its reaction in relation to the sunflower pathogens: Botrytis cinerea and Sclerotinia sclerotiorum.

  1. 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.

  2. 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.

  3. 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

  4. INFLUENCE OF CROP SYSTEMS IN REDUCING OF DROUGHT EFFECT FOR SUNFLOWER PLANTS

    Directory of Open Access Journals (Sweden)

    Nicolae IONESCU

    2015-10-01

    Full Text Available Along with cereals, sunflower is species which has seen a significant expansion in plant structure on a farm (Brad, 1990. The economic advantages of this are important (Hera et al., 1989, and by creating new hybrids are always looking for the potential to be as their genetic filled in. A lot of the new hybrids have also a good resistance for drought seasons (Pârjol et al., 1971. In the paper there was a prospect of these new genetic possibilities in terms white luvicsoil of southern territory (Ionescu et al., 1983. Were experienced three times of sowing, three densities and three hybrids in recent years. The period studied included a very dry year (2012, a favorable year (2013 and a middle one (2014. Of all the factors, the greatest influence was a time of sowing, respectively were observed large losses of grain production by delaying sowing (Bîlteanu, 1993. The time in which most hybrids produced very well was 1 to 30 April. All hybrids sown in May produced significantly negative do to drought conditions (Vrânceanu, 1974. Density had only positive influence in medium climatic environment (Holliday, 1960; Robinson et al, 1980 and less in the very favorable one. In the background of very dry, high densities (50 and 70 plants.ha-1 grain yield formation disfavored. Investigated hybrids with high production potential, behaved rather differently, because their reaction for experiment factors was less obvious. Therefore, new hybrids Sandrina, Flornil and the latest F. 911 and F. 708 alongside Favorit is recommended for cultivation in southern white luvicsoil conditions.

  5. Compendium of sunflower disease and insect pests

    Science.gov (United States)

    The Compendium of Sunflower Diseases and Pests is a new addition to the popular APS Press series of plant disease compendia. This will be the most comprehensive guide to sunflower diseases and pests in the world. The introduction contains brief histories of sunflower use and production, botany of th...

  6. Performance of some sunflower genotypes grown under dry weather conditions in south Bulgaria

    Directory of Open Access Journals (Sweden)

    Nurettin Tahsin

    2015-09-01

    Full Text Available Information on yield and agricultural performance of new sunflower (Helianthus annuus L. hybrids grown under dry weather conditions in South Bulgaria is limited. The objectives of this field study is to acquire information on seed yield and other agricultural characteristics of five sunflower hybrids and their parental lines in South Bulgaria. This research was carried out on the Experimental farm at the Agricultural University in Plovdiv, Bulgaria in the seasons of 2008 and 2009. Statistical analysis revealed that the differences among genotypes for all studied characters were significant in both seasons as well as in the combined one.

  7. 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.

  8. 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.

  9. Changes in sunflower breeding over the last fifty years

    Directory of Open Access Journals (Sweden)

    Vear Felicity

    2016-03-01

    Full Text Available This article discusses changes in sunflower breeding objectives since the introduction of hybrid varieties 50 years ago. After a reminder of the importance of some early programmes, Canadian in particular, the present situation for each breeding objective is compared with those encountered earlier. Breeding for yield has changed from maximum possible yield under intensive agriculture to yield with resistance to abiotic stresses, moderate droughts and shallow soils in particular, helped by collaboration with agronomists to produce crop models. Breeding for oil has changed from quantity to quality and the value of seed meal is again becoming economically important. Necessary disease resistances vary with agronomic practises and selection pressure on pathogens according to varietal genetics. The possibilities of new types of sunflower are also discussed. Advances in genomics will change breeding procedures, but with rapidly changing molecular techniques, international collaboration is particularly important.

  10. 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

  11. 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.

  12. Rhizobium helianthi sp. nov., isolated from the rhizosphere of sunflower.

    Science.gov (United States)

    Wei, Xuexin; Yan, Shouwei; Li, Dai; Pang, Huancheng; Li, Yuyi; Zhang, Jianli

    2015-12-01

    A Gram-stain-negative, non-spore-forming, rod-shaped and aerobic bacterium, designated Xi19T, was isolated from a soil sample collected from the rhizosphere of sunflower (Helianthus annuus) in Wuyuan county of Inner Mongolia, China and was characterized taxonomically by using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel isolate was related to species of the genus Rhizobium, sharing the greatest 16S rRNA gene sequence similarity with Rhizobium rhizoryzae J3-AN59T (98.4 %), followed by Rhizobium pseudoryzae J3-A127T (97.4 %). There were low similarities ( Rhizobium. DNA-DNA hybridization values between strain Xi19T and the most related strain Rhizobium rhizoryzae J3-AN59T were low. The major cellular fatty acids of strain Xi19T were C16 : 0, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C19 : 0 cyclo ω8c. Q-10 was identified as the predominant ubiquinone and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. The DNA G+C content of strain Xi19T was 60.2 mol%. On the basis of physiological and biochemical characteristics, coupled with genotypic data obtained in this work, strain Xi19T represents a novel species of the genus Rhizobium, for which the name Rhizobium helianthi is proposed. The type strain is Xi19T ( = CGMCC 1.12192T = KCTC 23879T).

  13. Genetic possibilities for altering sunflower oil quality to obtain novel oils.

    Science.gov (United States)

    Skorić, Dragan; Jocić, Sinisa; Sakac, Zvonimir; Lecić, Nada

    2008-04-01

    The sunflower is one of the four most important oilseed crops in the world, and the nutritional quality of its edible oil ranks among the best vegetable oils in cultivation. Typically up to 90% of the fatty acids in conventional sunflower oil are unsaturated, namely oleic (C 18:1, 16%-19%) and linoleic (C 18:2, 68%-72%) fatty acids. Palmitic (C 16:0, 6%), stearic (C 18:0, 5%), and minor amounts of myristic (C 14:0), myristoleic (C 14:1), palmitoleic (C 16:1), arachidic (C 20:0), behenic (C 22:0), and other fatty acids account for the remaining 10%. Advances in modern genetics, most importantly induced mutations, have altered the fatty acid composition of sunflower oil to a significant extent. Treating sunflower seeds with gamma- and X-rays has produced mutants with 25%-30% palmitic acid. Sunflower seed treatment with X-rays has also resulted in mutants having 30% palmitoleic acid, while treatments with mutagenic sodium azide have produced seeds containing 35% stearic acid. The most important mutations have been obtained by treatment with dimethyl sulfate, which produced genotypes with more than 90% oleic acid. Mutants have also been obtained that have a high linoleic acid content (>80%) by treating seeds with X-rays and ethyl methanesulfonate. Of the vitamin E family of compounds, sunflower oil is known to predominantly contain alpha-tocopherol (>90%). Spontaneous mutations controlled by recessive genes have been discovered that significantly alter tocopherol forms and levels. The genes in question are tph(1) (50% alpha- and 50% beta-tocopherol), tph(2) (0%-5% alpha- and 95%-100% gamma-tocopherol), and tph(1)tph(2) (8%-40% alpha-, 0%-25% beta-, 25%-84% gamma-, and 8%-50% delta-tocopherol). The existence of (mutant) genes for increased levels of individual fatty acids and for different forms and levels of tocopherol enables the development of sunflower hybrids with different oil quality. The greatest progress has been made in developing high-oleic hybrids (>90

  14. 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.

  15. 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.

  16. Development, characterization and experimental validation of a cultivated sunflower (Helianthus annuus L. gene expression oligonucleotide microarray.

    Directory of Open Access Journals (Sweden)

    Paula Fernandez

    Full Text Available Oligonucleotide-based microarrays with accurate gene coverage represent a key strategy for transcriptional studies in orphan species such as sunflower, H. annuus L., which lacks full genome sequences. The goal of this study was the development and functional annotation of a comprehensive sunflower unigene collection and the design and validation of a custom sunflower oligonucleotide-based microarray. A large scale EST (>130,000 ESTs curation, assembly and sequence annotation was performed using Blast2GO (www.blast2go.de. The EST assembly comprises 41,013 putative transcripts (12,924 contigs and 28,089 singletons. The resulting Sunflower Unigen Resource (SUR version 1.0 was used to design an oligonucleotide-based Agilent microarray for cultivated sunflower. This microarray includes a total of 42,326 features: 1,417 Agilent controls, 74 control probes for sunflower replicated 10 times (740 controls and 40,169 different non-control probes. Microarray performance was validated using a model experiment examining the induction of senescence by water deficit. Pre-processing and differential expression analysis of Agilent microarrays was performed using the Bioconductor limma package. The analyses based on p-values calculated by eBayes (p<0.01 allowed the detection of 558 differentially expressed genes between water stress and control conditions; from these, ten genes were further validated by qPCR. Over-represented ontologies were identified using FatiScan in the Babelomics suite. This work generated a curated and trustable sunflower unigene collection, and a custom, validated sunflower oligonucleotide-based microarray using Agilent technology. Both the curated unigene collection and the validated oligonucleotide microarray provide key resources for sunflower genome analysis, transcriptional studies, and molecular breeding for crop improvement.

  17. Development, characterization and experimental validation of a cultivated sunflower (Helianthus annuus L.) gene expression oligonucleotide microarray.

    Science.gov (United States)

    Fernandez, Paula; Soria, Marcelo; Blesa, David; DiRienzo, Julio; Moschen, Sebastian; Rivarola, Maximo; Clavijo, Bernardo Jose; Gonzalez, Sergio; Peluffo, Lucila; Príncipi, Dario; Dosio, Guillermo; Aguirrezabal, Luis; García-García, Francisco; Conesa, Ana; Hopp, Esteban; Dopazo, Joaquín; Heinz, Ruth Amelia; Paniego, Norma

    2012-01-01

    Oligonucleotide-based microarrays with accurate gene coverage represent a key strategy for transcriptional studies in orphan species such as sunflower, H. annuus L., which lacks full genome sequences. The goal of this study was the development and functional annotation of a comprehensive sunflower unigene collection and the design and validation of a custom sunflower oligonucleotide-based microarray. A large scale EST (>130,000 ESTs) curation, assembly and sequence annotation was performed using Blast2GO (www.blast2go.de). The EST assembly comprises 41,013 putative transcripts (12,924 contigs and 28,089 singletons). The resulting Sunflower Unigen Resource (SUR version 1.0) was used to design an oligonucleotide-based Agilent microarray for cultivated sunflower. This microarray includes a total of 42,326 features: 1,417 Agilent controls, 74 control probes for sunflower replicated 10 times (740 controls) and 40,169 different non-control probes. Microarray performance was validated using a model experiment examining the induction of senescence by water deficit. Pre-processing and differential expression analysis of Agilent microarrays was performed using the Bioconductor limma package. The analyses based on p-values calculated by eBayes (p<0.01) allowed the detection of 558 differentially expressed genes between water stress and control conditions; from these, ten genes were further validated by qPCR. Over-represented ontologies were identified using FatiScan in the Babelomics suite. This work generated a curated and trustable sunflower unigene collection, and a custom, validated sunflower oligonucleotide-based microarray using Agilent technology. Both the curated unigene collection and the validated oligonucleotide microarray provide key resources for sunflower genome analysis, transcriptional studies, and molecular breeding for crop improvement.

  18. 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.

  19. 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.

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

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    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.

  1. Sequence-Based Analysis of Structural Organization and Composition of the Cultivated Sunflower (Helianthus annuus L. Genome

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    Navdeep Gill

    2014-04-01

    Full Text Available Sunflower is an important oilseed crop, as well as a model system for evolutionary studies, but its 3.6 gigabase genome has proven difficult to assemble, in part because of the high repeat content of its genome. Here we report on the sequencing, assembly, and analyses of 96 randomly chosen BACs from sunflower to provide additional information on the repeat content of the sunflower genome, assess how repetitive elements in the sunflower genome are organized relative to genes, and compare the genomic distribution of these repeats to that found in other food crops and model species. We also examine the expression of transposable element-related transcripts in EST databases for sunflower to determine the representation of repeats in the transcriptome and to measure their transcriptional activity. Our data confirm previous reports in suggesting that the sunflower genome is >78% repetitive. Sunflower repeats share very little similarity to other plant repeats such as those of Arabidopsis, rice, maize and wheat; overall 28% of repeats are “novel” to sunflower. The repetitive sequences appear to be randomly distributed within the sequenced BACs. Assuming the 96 BACs are representative of the genome as a whole, then approximately 5.2% of the sunflower genome comprises non TE-related genic sequence, with an average gene density of 18kbp/gene. Expression levels of these transposable elements indicate tissue specificity and differential expression in vegetative and reproductive tissues, suggesting that expressed TEs might contribute to sunflower development. The assembled BACs will also be useful for assessing the quality of several different draft assemblies of the sunflower genome and for annotating the reference sequence.

  2. Sequence-Based Analysis of Structural Organization and Composition of the Cultivated Sunflower (Helianthus annuus L.) Genome.

    Science.gov (United States)

    Gill, Navdeep; Buti, Matteo; Kane, Nolan; Bellec, Arnaud; Helmstetter, Nicolas; Berges, Hélène; Rieseberg, Loren H

    2014-04-16

    Sunflower is an important oilseed crop, as well as a model system for evolutionary studies, but its 3.6 gigabase genome has proven difficult to assemble, in part because of the high repeat content of its genome. Here we report on the sequencing, assembly, and analyses of 96 randomly chosen BACs from sunflower to provide additional information on the repeat content of the sunflower genome, assess how repetitive elements in the sunflower genome are organized relative to genes, and compare the genomic distribution of these repeats to that found in other food crops and model species. We also examine the expression of transposable element-related transcripts in EST databases for sunflower to determine the representation of repeats in the transcriptome and to measure their transcriptional activity. Our data confirm previous reports in suggesting that the sunflower genome is >78% repetitive. Sunflower repeats share very little similarity to other plant repeats such as those of Arabidopsis, rice, maize and wheat; overall 28% of repeats are "novel" to sunflower. The repetitive sequences appear to be randomly distributed within the sequenced BACs. Assuming the 96 BACs are representative of the genome as a whole, then approximately 5.2% of the sunflower genome comprises non TE-related genic sequence, with an average gene density of 18kbp/gene. Expression levels of these transposable elements indicate tissue specificity and differential expression in vegetative and reproductive tissues, suggesting that expressed TEs might contribute to sunflower development. The assembled BACs will also be useful for assessing the quality of several different draft assemblies of the sunflower genome and for annotating the reference sequence.

  3. 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.

  4. 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.

  5. 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.

  6. Determinação de espécie indicadora e comparação de genótipos de girassol quanto ao potencial alelopático Determination of indicative species and comparison of sunflower genotypes as to their allelopathic potential

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    H.L. Silva

    2009-01-01

    -de-viola. Houve grande variabilidade de potencial alelopático entre genótipos de girassol sobre a germinação e o crescimento radicular e da parte aérea de Bidens pilosa. Os resultados demonstram que a técnica da semeadura em substituição é adequada para detectar efeitos estimulativos ou inibitórios de girassol sobre espécies indicadoras e para discriminar genótipos de girassol quanto à habilidade em inibir ou estimular plântulas de Bidens pilosa.In modern agriculture, the chemical method is the most used for weed control because it is highly efficient, easy to apply, and demands limited labor. However, the inadequate use of chemical products can lead to environmental and human health problems. Thus, there is a growing need to search for alternative weed control methods using substances which are less energy-demanding, less toxic and less aggressive to the environment. This work aimed to evaluate the allelopathic potential of sunflower (Helianthus annuus culture on different weed and cultivated species, in two experiments conducted in a completely randomized design, using the relay seeding technique. The first experiment was carried out with four repetitions, in a bi-factorial scheme. The first factor was constituted by six indicative target species: beggarticks (Bidens spp., common morninglory (Ipomoea grandifolia, pigweed (Amaranthus hybridus, lettuce (Lactuca sativa, cv. Aurélia, tomato (Solanum lycopersicum, cv. Santa Cruz, and wheat (Triticum aestivum, cv. BRS 208.The second factor was constituted by the presence or absence of sunflower seedlings. The relay seeding technique was applied. The second experiment was composed by 24 treatments including 23 sunflower genotypes and a control without sunflower, with four repetitions. The indicative species was only the beggarticks. In both experiments, at the end of seven coexistence days, number of germinated seeds, and root and aerial part length of the target species were evaluated. No difference was observed among

  7. 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.

  8. Abelhas (Hymenoptera: Apoidea visitantes dos capítulos de girassol no recôncavo baiano Bees (Hymenoptera: Apoidea on sunflower flowers in Recôncavo Baiano region, Brazil

    Directory of Open Access Journals (Sweden)

    Cerilene Santiago Machado

    2006-10-01

    Full Text Available O girassol (Helianthus annuus L. é uma espécie de polinização cruzada, cujos principais polinizadores são as abelhas. Este trabalho teve por objetivo obter informações sobre a diversidade de abelhas visitantes nos capítulos de girassol, fornecendo subsídios para identificar os possíveis polinizadores efetivos na região do Recôncavo Baiano. As coletas das abelhas foram realizadas no período de setembro-outubro de 2004, janeiro-fevereiro e maio-junho de 2005 sobre os híbridos de girassol, "AG 920" e "AG 930", cultivados na área experimental de Entomologia do Centro de Ciências Agrárias e Ambientais da Universidade Federal da Bahia, em Cruz das Almas-BA. Um total de 26 espécies de abelhas foram identificadas, sendo que Apis mellifera foi a mais abundante (58,32%, seguida de Nannotrigona testaceicornis (18,53% e Trigona spinipes (11,37%. As demais espécies apresentaram uma freqüência relativa inferior a 5%.Sunflower, Helianthus annuus L., is a cross-pollinating plant whose main pollinator are bees. This work was airmed at getting information about the diversity of visiting bee on sunflower inflorescence, by identifing the possible sunflower pollinators in Recôncavo Baiano region. The bees were collected on September-October of 2004, January-February and May-June of 2005 sunflowers hybrids (AG 920 and AG 930 cultivated in the entomology experimental area of Centro de Ciências Agrárias e Ambiental da Universidade Federal da Bahia, Brazil. Twenty six species were identified Apis mellifera (58.32%, Nannotrigona testaceicornis (18.53% and Trigona spinipes (11.37% were the most abundant species. The other species presented a frequency lower than relative 5%.

  9. Mycoflora and mycotoxins of sunflower(helianthus annuus l.) Seeds in egypt 1. Sugar fungi and natural occurrence of mycotoxins

    OpenAIRE

    El Maraghy, S. S. Mohamed [سعد شحاتة محمد المراغي; El-Maghraby, O. M. O.

    1986-01-01

    Eighteen genera and sixty-three species, in addition to three varieties were isolated from thirty six samples of sunflower seeds collected from different places in Egypt. Aspergillus and Penicillium followed by Rhizopus and Fusarium were the most frequent genera. A. niger, A. flaws, A. jumigatus, A. terreus and P. chrysogenum were the most common species. Samples 11,4 and 8 of 36 sunflower samples were of high, moderate and low toxicity, respectively, to brine shrimp larvae and were naturally...

  10. 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.

  11. 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.

  12. Sunflower meal concentrations in Massai grass silage

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    Máikal S. Borja

    2012-08-01

    Full Text Available Objetive. This experiment was conducted to evaluate the best sunflower meal concentration in Massai grass silage. Materials and methods. The treatments were composed of 0, 8, 16, and 24% sunflower meal (natural matter basis during ensiling of Massai grass, with four repetitions. Results. The regression equation showed that the inclusion of sunflower meal between 2.14% and 13.91% obtained a silage dry matter between 25 and 35%, which are the values recommended for the production of high quality silage. The addition of sunflower meal showed a linear increase in crude protein, reaching 18% DM with the highest concentration of sunflower meal. The highest feed value index was obtained with the addition of 24% sunflower meal in the silage. The estimated total digestible nutrient of silage increased linearly with sunflower meal concentration. The silage pH values had a quadratic effect, reaching the lowest value (4.1 with 15% sunflower meal addition. Conclusions. Based on the chemical composition and forage quality, a concentration of 14% sunflower meal should be used for high-quality silage with good nutritional value.

  13. Mérito de seis híbridos y líneas derivadas de girasol durante el desarrollo de la podredumbre blanca de capítulos Performance of six sunflower hybrids and derived inbred lines during white rot development in capitula

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    A. Giussani

    2008-06-01

    Full Text Available Se apreció el comportamiento de seis cultivares F1 y líneas F2:3 de girasol frente a la podredumbre blanca del capítulo. A los genotipos se los inoculó con Sclerotinia sclerotiorum y se les estimó: la incidencia, el período de incubación relativo, la severidad -en dos momentos- y el progreso de la enfermedad. Hubo diferencias entre genotipos para las cinco variables medidas. El cultivar MG 50 sobresalió por su comportamiento frente a todas las variables, excepto incidencia. Algunas líneas F2:3 tuvieron un nivel de resistencia similar a los mejores cultivares del ensayo. Dichas líneas continúan en el proceso de endocría y evaluación por su habilidad de producir una progenie de buena resistencia durante todas las fases del desarrollo de la podredumbre blanca de capítulos en girasol.Six sunflower F1 cultivars and F2:3 lines, obtained from self-fertilization of these cultivars, were evaluated for white rot performance. Genotypes were inoculated with Sclerotinia sclerotiorum and the disease incidence, relative incubation period, disease severity -at 40 days after inoculation and at maturity- and daily growth lesion rate were quantified. There were different white rot performances for all variables and the cultivar MG 50 showed a high level of resistance for all variables, except incidence. Some derived F2:3 lines showed a similar level of resistance to that of the best cultivars. These lines are still in the inbreeding process and then crossed to detect hybrids with the most adequate level of resistance to white rot in sunflower capitula.

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

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    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

  15. [Comparative study of nuclear RNA and polysomal mRNA in sunflower seedlings].

    Science.gov (United States)

    Kuntsevich, V I; Tishchenko, E N; Lobov, V P; Zhil'ko, T D

    1994-01-01

    A comparative study of nRNA and polysomal mRNA complexity in the sunflower seedlings by molecular DNA:RNA hybridization method was carried out. It is established that nRNA complexity 4 times exceeds that of mRNA and is equal to 4.85.10(8) bp. Thus the nuclear RNA is expressed from at least 50.47% of single-copy DNA or 10.40% of genome. This data allow the presence of regulation of sunflower genome expression on the posttranscriptional level to be assumed.

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

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    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.

  17. 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...

  18. 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.

  19. 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.

  20. Chemical mutagenesis--a promising technique to increase metal concentration and extraction in sunflowers.

    Science.gov (United States)

    Nehnevajova, Erika; Herzig, Rolf; Federer, Guido; Erismann, Karl-Hans; Schwitzguébel, Jean-Paul

    2007-01-01

    Since most of the metal-hyperaccumulating wild plants only produce very low biomass and many high-yielding crops accumulate only moderate amounts of metals, the current research is mainly focused on overcoming these limitations and the optimization of metal phytoextraction. The main goal of the present study was the improvement of metal concentration and extraction properties of Helianthus annuus L by chemical mutagenesis (the non-GMO approach). Sunflowers--hybrid cultivar Salut and inbred lines-were treated with the chemical mutagen ethyl methanesulfonate (EMS). The effect of chemical mutagenesis on metal concentration in and extraction by new sunflower M1 and M2 mutants was directly assessed on a metal-contaminated field in Raft, Switzerland. Mutants of the M2 generation showed a 2-3 times higher metal shoot concentration than the control plants. The best M2 sunflower "giant mutant" 14/185/04 showed a significantly enhanced metal extraction ability: 7.5 times for Cd, 9.2 times for Zn, and 8.2 times for Pb in aboveground parts, as compared to the control plants. Theoretical calculations for the phytoextraction potential of new sunflower variants note that the best sunflower mutant can produce up to 26 t dry matter per hectare and remove 13.3 kg Zn per hectare and year at the sewage sludge contaminated site of Raft; that is a gain factor of 9 compared to Zn extraction by sunflower controls. Furthermore, the use of sunflower oil and biomass for technical purposes (lubricants, biodiesel, biogas) should produce an additional value and improve the economical balance of phytoextraction.

  1. 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.

  2. Emulsion properties of sunflower (Helianthus annuus) proteins

    NARCIS (Netherlands)

    Gonzalez-Perez, S.; Koningsveld, van G.A.; Vereijken, J.M.; Merck, K.B.; Gruppen, H.; Voragen, A.G.J.

    2005-01-01

    Emulsions were made with sunflower protein isolate (SI), helianthinin, and sunflower albumins (SFAs). Emulsion formation and stabilization were studied as a function of pH and ionic strength and after heat treatment of the proteins. The emulsions were characterized with respect to average droplet si

  3. Variation for seed phytosterols in sunflower germplasm

    Science.gov (United States)

    Sunflower (Helianthus annuus L.) seeds and oils are rich sources of phytosterols, which are important compounds for human nutrition. There is limited information on variability for seed phytosterols in sunflower germplasm. The objective of the present research was to evaluate kernel phytosterol cont...

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. Sunflower seedlings dry matter content as affected by chemical treatment and storage length

    Directory of Open Access Journals (Sweden)

    Mrđa Jelena

    2011-01-01

    Full Text Available Chemical treatment of seed is a common crop protection measure. In the case of sunflower seed, fungicides are used regularly and insecticides at an increasing rate. In some cases, sunflower hybrid seed not planted in the first year is planted in the second or even third year after production. Seed vigour decreases gradually over time, which negatively affects seed emergence and subsequent plant growth and development. Seed with high vigour is expected to germinate quickly, producing seedlings that grow fast and uniformly. The objective of this study was to assess the effects of seed chemical treatment and storage length on seedling dry matter content in different sunflower hybrids. The study included several variants with fungicide and pesticide treatments and an untreated control. In the case of the hybrid NS-H-111, highest values of the studied characteristic were recorded in the control and directly after chemical treatment. In the case of the hybrid Sremac, the lowest value was recorded in seed treatment with benomyl+metalaxyl, highest in the treatments directly after chemical treatment and in seed stored for six months. In the case of the hybrid Šumadinac, highest values were recorded in the control and in seed treatment with fludioxonil+metalaxyl, the lowest in seed treatment with fludioxonil+metalaxyl+im idacloprid. Regarding the effect of different seed storage periods, highest values of the studied characteristic were recorded shortly after chemical treatment and in seed stored for six months.

  9. Impact of abiotic stress on photosynthetic efficiency and leaf temperature in sunflower

    Directory of Open Access Journals (Sweden)

    Antonela Markulj Kulundžić

    2016-11-01

    Full Text Available The aim of this research was to investigate the variability of photosynthetic performance index (PIABS and leaf temperature values measured in V6 development phase on 13 sunflower hybrids, grown in stressful conditions. The pot trial was made up of two treatments, one (T1 with 60% Field Water Capacity (FWC, and the other one (T2 with 80% FWC. Significant differences between T1 and T2 treatments were established for both of these parameters which prove their dependence on the water content in the soil, while the influence of hybrid was evident only in the case of PIABS. Although in T1, as opposed to T2, all sunflower hybrids reacted by increasing leaf temperature, reaction to stress conditions measured with PIABS parameter was not uniform. Some of the hybrids reacted by decreasing PIABS values, while others reacted by increasing their PIABS values. Therefore, it can be concluded that changes in parameters were independent of each other, which was confirmed by correlation analysis. Investigated parameters are suitable for determining the existence of undesirable environmental conditions that cause stress in plants and can be used in breeding of sunflower to withstand abiotic stress conditions, i.e. in selection of stress tolerant hybrids.

  10. 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

  11. 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

  12. 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.

  13. 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

  14. Comparative pulping of sunflower stalks

    Directory of Open Access Journals (Sweden)

    Valerii Barbash

    2016-03-01

    Full Text Available The procedure of holocellulose content determination in non-wood plant raw materials was developed. The strength properties of pulp obtained from sunflower stalks by neutral-sulphite, soda, alkaline sulphite-anthraquinone-ethanol and peracetic methods of delignification were studied. Methodology of comparison of plant materials delignification methods using new lignin-carbohydrate diagram was proposed. It was shown, that the alkaline sulphite-anthraquinone-ethanol method of pulping is characterized by the highest delignification degree and is the most efficient among the studied methods

  15. Kinetic Modeling of Sunflower Grain Filling and Fatty Acid Biosynthesis

    Science.gov (United States)

    Durruty, Ignacio; Aguirrezábal, Luis A. N.; Echarte, María M.

    2016-01-01

    Grain growth and oil biosynthesis are complex processes that involve various enzymes placed in different sub-cellular compartments of the grain. In order to understand the mechanisms controlling grain weight and composition, we need mathematical models capable of simulating the dynamic behavior of the main components of the grain during the grain filling stage. In this paper, we present a non-structured mechanistic kinetic model developed for sunflower grains. The model was first calibrated for sunflower hybrid ACA855. The calibrated model was able to predict the theoretical amount of carbohydrate equivalents allocated to the grain, grain growth and the dynamics of the oil and non-oil fraction, while considering maintenance requirements and leaf senescence. Incorporating into the model the serial-parallel nature of fatty acid biosynthesis permitted a good representation of the kinetics of palmitic, stearic, oleic, and linoleic acids production. A sensitivity analysis showed that the relative influence of input parameters changed along grain development. Grain growth was mostly affected by the specific growth parameter (μ′) while fatty acid composition strongly depended on their own maximum specific rate parameters. The model was successfully applied to two additional hybrids (MG2 and DK3820). The proposed model can be the first building block toward the development of a more sophisticated model, capable of predicting the effects of environmental conditions on grain weight and composition, in a comprehensive and quantitative way. PMID:27242809

  16. 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.

  17. Very long chain fatty acid synthesis in sunflower kernels.

    Science.gov (United States)

    Salas, Joaquín J; Martínez-Force, Enrique; Garcés, Rafael

    2005-04-01

    Most common seed oils contain small amounts of very long chain fatty acids (VLCFAs), the main components of oils from species such as Brassica napus or Lunnaria annua. These fatty acids are synthesized from acyl-CoA precursors in the endoplasmic reticulum through the activity of a dissociated enzyme complex known as fatty acid elongase. We studied the synthesis of the arachidic, behenic, and lignoceric VLCFAs in sunflower kernels, in which they account for 1-3% of the saturated fatty acids. These VLCFAs are synthesized from 18:0-CoA by membrane-bound fatty acid elongases, and their biosynthesis is mainly dependent on NADPH equivalents. Two condensing enzymes appear to be responsible for the synthesis of VLCFAs in sunflower kernels, beta-ketoacyl-CoA synthase-I (KCS-I) and beta-ketoacyl-CoA synthase-II (KCS-II). Both of these enzymes were resolved by ion exchange chromatography and display different substrate specificities. While KCS-I displays a preference for 20:0-CoA, 18:0-CoA was more efficiently elongated by KCS-II. Both enzymes have different sensitivities to pH and Triton X-100, and their kinetic properties indicate that both are strongly inhibited by the presence of their substrates. In light of these results, the VLCFA composition of sunflower oil is considered in relation to that in other commercially exploited oils.

  18. Maize, Sunflower and Barley Sensitivity to the Residual Activity of Clomazone in Soil

    Directory of Open Access Journals (Sweden)

    Jelena Gajić Umiljendić

    2012-01-01

    Full Text Available Sensitivity of maize, sunflower and barley to clomazone residues in loamy soil wasassessed in the study using bioassay. Clomazone was applied at a series of concentrationsfrom 0.12 to 12 mg a.i./kg of soil. After 14 days, morphological (shoot height, fresh and dryweight and physiological (content of carotenoids, chlorophyll a and chlorophyll b parameterswere measured. The results showed that morphological parameters are not valid indicatorsof clomazone sensitivity. Based on the results showing inhibition of the physiologicalparameters, I50 values were calculated and used to estimate the difference in sensitivitybetween the species tested. Sunflower was the most sensitive species, while the differencein sensitivity between maize and barley was not significant.Nomenclature: clomazone (2-(2-chlorbenzyl-4,4-dimethyl-1,2-oxazolidin-3-one, maize(Zea mays L., sunflower (Helianthus annuus L., barley (Hordeum vulgare L.

  19. 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.

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  2. 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.

  3. 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.

  4. 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.

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

    Science.gov (United States)

    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.

  6. Detection of single copy sequences using BAC-FISH and C-PRINS techniques in sunflower chromosomes.

    Science.gov (United States)

    Talia, Paola; Greizerstein, Eduardo J; Hopp, H Esteban; Paniego, Norma; Poggio, Lidia; Heinz, Ruth A

    2011-04-01

    Bacterial artificial chromosome-fluorescence in situ hybridization (BAC-FISH) and cycling-primed in situ labeling (C-PRINS) techniques were evaluated for integration of physical and genetic maps of sunflower (Helianthus annuus L.). Single-site SSR markers were selected from three linkage groups of a high-density sunflower genetic map. This selection was based on previously identified QTL associated to S. sclerotiorum. These markers were used to select BACs contaning single copy sequences for BAC-FISH aplication. Blocking of highly dispersed repetitive sunflower sequences reduced unspecific hybridization, and allowed the detection of specific signals for BACs containing SSR markers HA4222 and HA2600, anchored to LG 16 and LG 10, respectively. Single-site FISH signal detection was optimized by adjusting the relative quantity and quality of unlabelled repetitive sequences present in the blocking DNA. The SSR marker ORS1247 anchored to the LG 17 was detected by C-PRINS, which yielded fluorescence signals that were specific and intense. This progress in localizing single-copy sequences using BAC-FISH and indirect C-PRINS strategies in sunflower will facilitate the integration of genetic and physical maps, allowing the identification of chromosomes containing key genes and/or QTL associated to agronomic important traits in sunflower.

  7. Development of an ultra-dense genetic map of the sunflower genome based on single-feature polymorphisms.

    Directory of Open Access Journals (Sweden)

    John E Bowers

    Full Text Available The development of ultra-dense genetic maps has the potential to facilitate detailed comparative genomic analyses and whole genome sequence assemblies. Here we describe the use of a custom Affymetrix GeneChip containing nearly 2.4 million features (25 bp sequences targeting 86,023 unigenes from sunflower (Helianthus annuus L. and related species to test for single-feature polymorphisms (SFPs in a recombinant inbred line (RIL mapping population derived from a cross between confectionery and oilseed sunflower lines (RHA280×RHA801. We then employed an existing genetic map derived from this same population to rigorously filter out low quality data and place 67,486 features corresponding to 22,481 unigenes on the sunflower genetic map. The resulting map contains a substantial fraction of all sunflower genes and will thus facilitate a number of downstream applications, including genome assembly and the identification of candidate genes underlying QTL or traits of interest.

  8. 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...

  9. Interspecific amphiploid-derived alloplasmic male sterility with defective anthers, narrow disk florets, and small ray flowers in sunflower

    Science.gov (United States)

    The cytoplasmic male-sterility (CMS)/fertility-restoration system is important for hybrid sunflower (Helianthus annuus L.) seed production. Two novel alloplasmic CMSs, designated CMS GRO1 and CMS MAX3 with defective anthers, narrow disk florets with no swollen corolla, and short, narrow ray flowers,...

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

    Science.gov (United States)

    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.

  11. Impact of planting date on sunflower beetle (Coleoptera: Chrysomelidae) infestation, damage, and parasitism in cultivated sunflower.

    Science.gov (United States)

    Charlet, Laurence D; Knodel, Janet J

    2003-06-01

    The sunflower beetle, Zygogramma exclamationis (F.), is the major defoliating pest of sunflower (Helianthus annuus L.). Planting date was evaluated as a potential management tool in a variety of production regions throughout North Dakota from 1997 to 1999, for its impact on sunflower beetle population density of both adults and larvae, defoliation caused by both feeding stages, seed yield, oil content, and larval parasitism in cultivated sunflower. Results from this 3-yr study revealed that sunflower beetle adult and larval populations decreased as planting date was delayed. Delayed planting also reduced defoliation from adult and larval feeding, which is consistent with the lower numbers of the beetles present in the later seeded plots. Even a planting delay of only 1 wk was sufficient to significantly reduce feeding damage to the sunflower plant. Yield reduction caused by leaf destruction of the sunflower beetle adults and larvae was clearly evident in the first year of the study. The other component of sunflower yield, oil content, did not appear to be influenced by beetle feeding. The tachinid parasitoid, Myiopharus macellus (Rheinhard), appeared to be a significant mortality factor of sunflower beetle larvae at most locations regardless of the dates of planting, and was able to attack and parasitize the beetle at various larval densities. The results of this investigation showed the potential of delayed planting date as an effective integrated pest management tactic to reduce sunflower beetle adults, larvae, and their resulting defoliation. In addition, altering planting dates was compatible with biological control of the beetle, because delaying the planting date did not reduce the effectiveness of the parasitic fly, M. macellus, which attacks the sunflower beetle larvae.

  12. Effects of mass transfer and hydrogen pressure on the fixed-bed pyrolysis of sunflower bagasse

    Energy Technology Data Exchange (ETDEWEB)

    Putun, E.; Kockar, O.M.; Gercel, F. [Anadolu Univ., Eskisehir (Turkey)] [and others

    1994-12-31

    There are a number of waste and biomass sources being considered as potential sources of fuels and chemical feedstocks. The economics for biomass pyrolysis are generally considered to be most favourable for (1) plants which grow abundantly and require little cultivation in and lands and (2) wastes available in relatively large quantities from agricultural plants, for example, sunflower and hazel nuts. For the former, one such group of plants is Euphorbiaceae which are characterised by their ability to produce a milky latex, an emulsion of about 30% w/w terpenoids in water. One species in the family, Euphorbia Rigida from Southwestern Anatolia, Turkey is cultivated in close proximity to the sunflower growing regions and their oil extraction plants. The Turkish sunflower oil industry generates 800,000 tons of extraction residue (bagasse) per annum. Thus, both sunflower wastes and latex-producing plants are being considered as feedstocks for a future thermochemical demonstration unit in Turkey. Pyrolysis at relatively high hydrogen pressures (hydropyrolysis) has not been widely investigated for biomass. A potential advantage of hydropyrolysis is the ability to upgrade tar vapours over hydroprocessing catalysts. Fixed-bed pyrolysis and hydropyrolysis experiments have been conducted on sunflower bagasse to assess the effects of mass transfer and hydrogen pressure on oil yield and quality.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Molecular analysis of a new cytoplasmic male sterile genotype in sunflower

    NARCIS (Netherlands)

    Spassova, Mariana; Christov, Michail; Bohorova, Natasha; Petrov, Peter; Dudov, Kalin; Atanassov, Atanas; Nijkamp, H. John J.; Hille, Jaques

    1992-01-01

    Mitochondrial DNA from 1 fertile and 6 cytoplasmic male sterile (CMS) sunflower genotypes was studied. The CMS genotypes had been obtained either by specific crosses between different Helianthus species or by mutagenesis. CMS-associated restriction fragment length polymorphisms (RFLPs) were found in

  15. Molecular analysis of a new cytoplasmic male sterile genotype in sunflower

    NARCIS (Netherlands)

    Spassova, Mariana; Christov, Michail; Bohorova, Natasha; Petrov, Peter; Dudov, Kalin; Atanassov, Atanas; Nijkamp, H. John J.; Hille, Jaques

    1992-01-01

    Mitochondrial DNA from 1 fertile and 6 cytoplasmic male sterile (CMS) sunflower genotypes was studied. The CMS genotypes had been obtained either by specific crosses between different Helianthus species or by mutagenesis. CMS-associated restriction fragment length polymorphisms (RFLPs) were found in

  16. 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...

  17. Phoma Macdonaldi on seed and its importance in etiology of Phoma black stem in sunflower

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    Maširević Stevan N.

    2014-01-01

    Full Text Available Phoma macdonaldi Boerema, teleomorph Leptosphaeria lindquistii Frezzi, is a widespread pathogen of sunflower. The aim of this research was to identify the presence of fungus P. macdonaldi in seed of different sunflower hybrids, as well as the correlation between seed and field infection. Phoma black stem assessment was performed on three hybrids grown in six localities in Serbia. Untreated and processed seeds of these hybrids were used in the seed health test. Severity of the disease did not differ between localities. Average disease index for hybrids H7, H9 and H19 was 14.01%, 13.25% and 11.83% respectively, and it shows that there are no significant differences in hybrid susceptibility. The index of disease indicates tolerance of these hybrids to Phoma black stem. Seed analysis showed the presence of fungi from the following genera: Phoma, Alternaria, Botrytis, Sclerotinia, Penicillium and Aspergillus. Seed infection with Phoma (of the untreated seeds per hybrid ranged from 1.2-3.5%. There is no significant correlation between stem and seed infection.

  18. 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.

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

    Science.gov (United States)

    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.

  20. 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...

  1. Undermethylation associated with retroelement activation and chromosome remodelling in an interspecific mammalian hybrid.

    Science.gov (United States)

    O'Neill, R J; O'Neill, M J; Graves, J A

    1998-05-07

    Genetic models predict that genomic rearrangement in hybrids can facilitate reproductive isolation and the formation of new species by preventing gene flow between the parent species and hybrid (sunflowers are an example). The mechanism underlying hybridization-induced chromosome remodelling is as yet unknown, although mobile element activity has been shown to be involved in DNA rearrangement in some dysgenic Drosophila hybrids. It has been proposed that DNA methylation evolved as a means of repressing the movement of mobile elements (the host defence model). If such a protective mechanism were to fail, mobile elements could be activated, and could cause major and rapid genome alterations. Here we demonstrate the occurrence of genome-wide undermethylation, retroviral element amplification and chromosome remodelling in an interspecific mammalian hybrid (Macropus eugenii x Wallabia bicolor). Atypically extended centromeres of Macropus eugenii derived autosomes in the hybrid were composed primarily of an unmethylated, amplified retroviral element not detectable in either parent species. These results, taken with the observation of deficient methylation and de novo chromosome change in other mammalian hybrids, indicate that the failure of DNA methylation and subsequent mobile-element activity in hybrids could facilitate rapid karyotypic evolution.

  2. Registration of an oilseed sunflower germplasm HA-DM1 resistant to sunflower downy mildew

    Science.gov (United States)

    HA-DM1 (Reg. No.xxx, PI 674793) sunflower (Helianthus annuus L.) germplasm was developed and released cooperatively by the USDA-ARS, Sunflower and Plant Biology Research Unit and the North Dakota Agricultural Experiment Station in 2015. HA-DM1 is a BC2F4 derived oilseed maintainer line from the cros...

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

    Directory of Open Access Journals (Sweden)

    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.

  4. 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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  10. SNP discovery and development of a high-density genotyping array for sunflower.

    Directory of Open Access Journals (Sweden)

    Eleni Bachlava

    Full Text Available Recent advances in next-generation DNA sequencing technologies have made possible the development of high-throughput SNP genotyping platforms that allow for the simultaneous interrogation of thousands of single-nucleotide polymorphisms (SNPs. Such resources have the potential to facilitate the rapid development of high-density genetic maps, and to enable genome-wide association studies as well as molecular breeding approaches in a variety of taxa. Herein, we describe the development of a SNP genotyping resource for use in sunflower (Helianthus annuus L.. This work involved the development of a reference transcriptome assembly for sunflower, the discovery of thousands of high quality SNPs based on the generation and analysis of ca. 6 Gb of transcriptome re-sequencing data derived from multiple genotypes, the selection of 10,640 SNPs for inclusion in the genotyping array, and the use of the resulting array to screen a diverse panel of sunflower accessions as well as related wild species. The results of this work revealed a high frequency of polymorphic SNPs and relatively high level of cross-species transferability. Indeed, greater than 95% of successful SNP assays revealed polymorphism, and more than 90% of these assays could be successfully transferred to related wild species. Analysis of the polymorphism data revealed patterns of genetic differentiation that were largely congruent with the evolutionary history of sunflower, though the large number of markers allowed for finer resolution than has previously been possible.

  11. SNP discovery and development of a high-density genotyping array for sunflower.

    Science.gov (United States)

    Bachlava, Eleni; Taylor, Christopher A; Tang, Shunxue; Bowers, John E; Mandel, Jennifer R; Burke, John M; Knapp, Steven J

    2012-01-01

    Recent advances in next-generation DNA sequencing technologies have made possible the development of high-throughput SNP genotyping platforms that allow for the simultaneous interrogation of thousands of single-nucleotide polymorphisms (SNPs). Such resources have the potential to facilitate the rapid development of high-density genetic maps, and to enable genome-wide association studies as well as molecular breeding approaches in a variety of taxa. Herein, we describe the development of a SNP genotyping resource for use in sunflower (Helianthus annuus L.). This work involved the development of a reference transcriptome assembly for sunflower, the discovery of thousands of high quality SNPs based on the generation and analysis of ca. 6 Gb of transcriptome re-sequencing data derived from multiple genotypes, the selection of 10,640 SNPs for inclusion in the genotyping array, and the use of the resulting array to screen a diverse panel of sunflower accessions as well as related wild species. The results of this work revealed a high frequency of polymorphic SNPs and relatively high level of cross-species transferability. Indeed, greater than 95% of successful SNP assays revealed polymorphism, and more than 90% of these assays could be successfully transferred to related wild species. Analysis of the polymorphism data revealed patterns of genetic differentiation that were largely congruent with the evolutionary history of sunflower, though the large number of markers allowed for finer resolution than has previously been possible.

  12. 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.

  13. Sunflower seeds as eliciting agents of Compositae dermatitis

    DEFF Research Database (Denmark)

    Paulsen, Evy; El-Houri, Rime B; Andersen, Klaus Ejner;

    2015-01-01

    BACKGROUND: Sunflowers may cause dermatitis because of allergenic sesquiterpene lactones (SLs). Contact sensitization to sunflower seeds has also been reported, but the allergens are unknown. OBJECTIVES: To analyse sunflower seeds for the presence of SLs and to assess the prevalence of sunflower...... sensitization in Compositae-allergic individuals. PATIENTS/MATERIALS/METHODS: Sunflower-sensitive patients were identified by aimed patch testing. A dichloromethane extract of whole sunflower seeds was analysed by liquid chromatography-mass spectrometry and high-performance liquid chromatography. RESULTS......: The prevalence of sensitivity to sunflower in Compositae-allergic individuals was 56%. A solvent wash of whole sunflower seeds yielded an extract containing SLs, the principal component tentatively being identified as argophyllin A or B, other SLs being present in minute amounts. CONCLUSIONS: The concentration...

  14. A sunflower WRKY transcription factor stimulates the mobilization of seed-stored reserves during germination and post-germination growth.

    Science.gov (United States)

    Raineri, Jesica; Hartman, Matías D; Chan, Raquel L; Iglesias, Alberto A; Ribichich, Karina F

    2016-09-01

    The sunflower transcription factor HaWRKY10 stimulates reserves mobilization in Arabidopsis. Gene expression and enzymes activity assays indicated that lipolysis and gluconeogenesis were increased. Microarray results suggested a parallelism in sunflower. Germinating oilseeds converts stored lipids into sugars, and thereafter in metabolic energy that is used in seedling growth and establishment. During germination, the induced lipolysis linked to the glyoxylate pathway and gluconeogenesis produces sucrose, which is then transported to the embryo and driven through catabolic routes. Herein, we report that the sunflower transcription factor HaWRKY10 regulates carbon partitioning by reducing carbohydrate catabolism and increasing lipolysis and gluconeogenesis. HaWRKY10 was regulated by abscisic acid and gibberellins in the embryo leaves 48 h after seed imbibition and highly expressed during sunflower seed germination and seedling growth, concomitantly with lipid mobilization. Sunflower leaf disks overexpressing HaWRKY10 showed repressed expression of genes related to sucrose cleavage and glycolysis compared with controls. Moreover, HaWRKY10 constitutive expression in Arabidopsis seeds produced higher decrease in lipid reserves, whereas starch and sucrose were more preserved compared with wild type. Gene transcripts abundance and enzyme activities involved in stored lipid mobilization and gluconeogenesis increased more in transgenic than in wild type seeds 36 h after imbibition, whereas the negative regulator of lipid mobilization, ABI4, was repressed. Altogether, the results point out a functional parallelism between tissues and plant species, and reveal HaWRKY10 as a positive regulator of storage reserve mobilization in sunflower.

  15. 7 CFR 810.1801 - Definition of sunflower seed.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Definition of sunflower seed. 810.1801 Section 810... STATES STANDARDS FOR GRAIN United States Standards for Sunflower Seed Terms Defined § 810.1801 Definition of sunflower seed. Grain that, before the removal of foreign material, consists of 50.0 percent...

  16. Mycoflora and occurrence of alternariol and alternariol monomethyl ether in Brazilian sunflower from sowing to harvest.

    Science.gov (United States)

    Pozzi, Claudia R; Braghini, Raquel; Arcaro, Juliana R P; Zorzete, Patricia; Israel, Ana Lia M; Pozar, Ivani Otsuk; Denucci, Silmar; Corrêa, Benedito

    2005-07-13

    The present study aimed to analyze the mycoflora and the occurrence of alternariol (AOH) and alternariol monomethyl ether (AME) in grain samples of sunflower during different stages of plant development in Nova Odessa, State of São Paulo, Brazil. The data obtained were correlated with the presence of fungi in soil, wind-dispersed fungi, and the predominant climatic conditions of the region where the experiment was carried out. Analysis of the mycoflora revealed the presence of Fusarium verticillioides and Alternaria alternata in 70% and 46% of the samples, respectively. The profile of wind-dispersed fungi also showed F. verticillioides as the most frequently isolated fungus (68%), although A. alternata was detected in 28% of samples. In soil, Penicillium was the most frequent species (49.9%), followed by F. verticillioides (47.7%) and A. alternata (10.9%). Regarding water activity, sunflower grains presenting a high frequency of isolation of F. verticillioides and A. alternatahad a water activity ranging from 0.92 to 0.96, and statistical analysis revealed a negative linear correlation between the isolation of fungi and water activity. HPLC analysis showed that 18% of the sunflower grains were contaminated with alternariol (24.9-170.9 ng/g) and 10% with alternariol monomethyl ether (14.1-108.6 ng/g). The contamination of sunflower grains with AOH and AME in the field was low when compared to the LD50 necessary to cause toxicity to animals. However, the contamination with other toxigenic fungi such as F. verticillioides may indicate the presence of other mycotoxins in sunflower grains and a possible synergistic effect between them. This is the first report of the natural occurrence of alternariol and alternariol monomethyl ether in sunflower grains in Brazil.

  17. Phytoextraction potential of sunflower and white mustard plants in zinc-contaminated soil

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    Marta Zalewska

    2014-12-01

    Full Text Available Phytoextraction relies on plants with a high capacity to absorb heavy metals and remove them from the soil. The objective of this study was to analyze the potential of sunflower (Helianthus annuus L. and white mustard (Sinapis alba L. for phytoextraction of Zn-contaminated soil. Research was based on a strict pot experiment conducted in a greenhouse. Seven treatments were established with increasing Zn concentrations: 0, 25, 50, 100, 200, 400, and 600 mg Zn kg-1 air-dry soil. The first tested plant was fodder sunflower. In the following year, white mustard was sown in the same pots. Plants were harvested at the end of the flowering stage. The toxic effect of Zn on sunflower yields occurred at the contamination level of 200 mg Zn kg-1 soil. In the second year of the experiment, a significant decrease in mustard biomass took place in response to 400 mg Zn kg-1 soil. The contamination level of 600 mg Zn kg-1 soil resulted in complete plant death. Plant growth was not inhibited even at high tissue Zn concentrations of 515 mg Zn kg-1 sunflower DM and 422 mg Zn kg-1 mustard DM. The 2-yr cropping system did not contribute to a significant decrease in soil Zn content. Despite high concentrations of Zn in sunflower and mustard plants, total Zn uptake accounted for only 1% to 8% of the Zn rate introduced into the soil. However, in the long run, the growing of crops could reduce Zn contamination levels in the soil. The relatively high tolerance of sunflower and white mustard for Zn contamination and rapid growth of these species are possible alternatives for phytoextraction and phytostabilization of Zn-contaminated soil.

  18. 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

  19. 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

  20. 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.

  1. 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

  2. Registration of a male fertility restorer oilseed sunflower germplasm HA-R9 resistant to sunflower rust

    Science.gov (United States)

    The sunflower (Helianthus annuus L.) germplasm HA-R9 (Reg. No.xxx, PI 667595) was developed by the USDA-ARS, Sunflower and Plant Biology Research Unit in collaboration with the Agricultural Experiment Station of North Dakota State University and released in January, 2013. Sunflower rust (caused by P...

  3. 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.

  4. 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.

  5. SSRs and INDELs mined from the sunflower EST database: abundance, polymorphisms, and cross-taxa utility.

    Science.gov (United States)

    Heesacker, Adam; Kishore, Venkata K; Gao, Wenxiang; Tang, Shunxue; Kolkman, Judith M; Gingle, Alan; Matvienko, Marta; Kozik, Alexander; Michelmore, Richard M; Lai, Zhao; Rieseberg, Loren H; Knapp, Steven J

    2008-11-01

    Simple sequence repeats (SSRs) are abundant and frequently highly polymorphic in transcribed sequences and widely targeted for marker development in eukaryotes. Sunflower (Helianthus annuus) transcript assemblies were built and mined to identify SSRs and insertions-deletions (INDELs) for marker development, comparative mapping, and other genomics applications in sunflower. We describe the spectrum and frequency of SSRs identified in the sunflower EST database, a catalog of 16,643 EST-SSRs, a collection of 484 EST-SSR and 43 EST-INDEL markers developed from common sunflower ESTs, polymorphisms of the markers among the parents of several intraspecific and interspecific mapping populations, and the transferability of the markers to closely and distantly related species in the Compositae. Of 17,904 unigenes in the transcript assembly, 1,956 (10.9%) harbored one or more SSRs with repeat counts of n > or = 5. EST-SSR markers were 1.6-fold more polymorphic among exotic than elite genotypes and 0.7-fold less polymorphic than non-genic SSR markers. Of 466 EST-SSR or INDEL markers screened for cross-species amplification and polymorphisms, 413 (88.6%) amplified alleles from one or more wild species (H. argophyllus, H. tuberosus, H. anomalus, H. paradoxus, and H. deserticola), whereas 69 (14.8%) amplified alleles from safflower (Carthamus tinctorius) and 67 (14.4%) amplified alleles from lettuce (Lactuca sativa); hence, only a fraction were transferable to distantly related genera in the Compositae, whereas most were transferable to wild relatives of H. annuus. Several thousand additional SSRs were identified in the EST database and supply a wealth of templates for EST-SSR marker development in sunflower.

  6. Comparison of germination and seed vigor of sunflower in two contaminated soils of different texture

    Science.gov (United States)

    Zhao, Xin; Han, Jaemaro; Lee, Jong Keun; Kim, Jae Young

    2014-05-01

    Phytoremediation as an emerging low-cost and ecologically friendly alternative to the conventional soil remediation technologies has gained a great deal of attention and into lots of research. As a kind of the methods that use of green plants to remediate heavy metals contaminated soils, the early growth status of plant seeds in the contaminated environmental directly affects the effect of phytoremediation. Germination test in the water (aqueous solution of heavy metal) is generally used for assessing heavy metal phytotoxicity and possibility of plant growth, but there is a limit. Because soil is commonly main target of phytoremediation, not the water. The bioavailability of heavy metals in the soil also depends on the texture. So soil texture is an important factor of phytoremediation effect. Sunflower is the representative species which have good tolerance to various heavy metals; furthermore, the seeds of sunflower can be used as the raw-material for producing bio-diesel. The objectives of this research were to investigate germination rate of sunflowers in various heavy metal contaminated soils and to compare the seedling vigor index (SVI) of sunflower in two contaminated soils of different texture. Sunflower (Helianthusannuus L.) seeds were obtained from a commercial market. In order to prove the soil texture effect on heavy metal contaminated soil, germination tests in soil were conducted with two different types of soil texture (i.e., loam soil and sandy loam soil) classified by soil textural triangle (defined by USDA) including representative soil texture of Korea. Germination tests in soil were conducted using KS I ISO 11260-1 (2005) for reference that sunflower seeds were incubated for 7 days in dark at 25 ± 1 Celsius degree. The target heavy metals are Nickel (Ni) and Zinc (Zn). The Ni and Zn concentrations were 0, 10, 50, 100, 200, 300, 500 mg-Ni/kg-dry soil, and 0, 10, 50, 100, 300, 500, 900 mg-Zn/kg-dry soil, respectively. After germination test for 7

  7. 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.

  8. 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

  9. 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.

  10. Energy balance comparison of sorghum and sunflower

    Science.gov (United States)

    Rachidi, F.; Kirkham, M. B.; Kanemasu, E. T.; Stone, L. R.

    1993-03-01

    An understanding of the energy exchange processes at the surface of the earth is necessary for studies of global climate change. If the climate becomes drier, as is predicted for northern mid-latitudes, it is important to know how major agricultural crops will play a role in the budget of heat and moisture. Thus, the energy balance components of sorghum [ Sorghum bicolor (L.) Moench.] and sunflower ( Helianthus annuus L.), two drought-resistant crops grown in the areas where summertime drying is forecasted, were compared. Soil water content and evapotranspiration ( ET) rates also were determined. Net radiation was measured with net radiometers. Soil heat flux was analyzed with heat flux plates and thermocouples. The Bowen ratio method was used to determine sensible and latent heat fluxes. Sunflower had a higher evapotranspiration rate and depleted more water from the soil than sorghum. Soil heat flux into the soil during the daytime was greater for sorghum than sunflower, which was probably the result of the more erect leaves of sorghum. Nocturnal net radiation loss from the sorghum crop was greater than that from the sunflower crop, perhaps because more heat was stored in the soil under the sorghum crop. But daytime net radiation values were similar for the two crops. The data indicated that models of climate change must differentiate nighttime net radiation of agricultural crops. Sensible heat flux was not always less (or greater) for sorghum compared to sunflower. Sunflower had greater daytime values for latent heat flux, reflecting its greater depletion of water from the soil. Evapotranspiration rates determined by the energy balance method agreed relatively well with those found by the water balance method. For example, on 8 July (43 days after planting), the ET rates found by the energy-balance and water-balance methods were 4.6 vs. 5.5 mm/day for sunflower, respectively; for sorghum, these values were 4.0 vs. 3.5 mm/day, respectively. If the climate does

  11. 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.

  12. 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.

  13. Características fenológicas, produtivas e qualitativas de híbridos de girassol em diferentes épocas de semeadura para produção de silagem Sowing dates effects on the phenology, yield and qualitative traits of sunflower hybrids for silage making

    Directory of Open Access Journals (Sweden)

    Renius Mello

    2006-06-01

    ógica.The objective of this study was to estimate the effect of three sowing dates: October (early, November (normal and December (late, on the phenological, yield and qualitative traits of four sunflower hybrids: Rumbosol-91 (forage, M-734 (double purpose, C-11 (double purpose and BRS-191 (grain grown for silage making. A 4 x 3 factorial treatment combination (four hybrids x three sowing dates was allocated in a randomized block design with four replications. The October sowing brought about longer cycle, higher plant height, and smaller seed head diameter and contribution due to the prevailing climatic conditions of lower temperature, insolation and photoperiod during the crop growth period. The Rumbosol-91 and BRS-191 hybrids sowed in November showed higher lodging plus stalk breaking proportion of about 49.6 and 65.7%, respectively. The BRS-191 and M-734 hybrids sowed in December showed higher biomass yields of 39.71 and 43.76 t ha-1 fresh matter and 11.31 and 11.41 t ha-1 drymatter, respectively. While the CP content increased, the NDF, ADF and ADL contents decreased from the stem, to the leaf and to the head plant fractions. The whole plant DM values ranged from 23.2% in the Rumbosol-91 hybrid sowed in November to 47.9% in the C-11 hybrid sowed in December, indicating that the hybrids have differentiated moisture retention capacity at similar physiologic maturity of the culture (R-9 phase. The CP values ranged from 7.0 to 15.7%, an evidence of the high protein content of the culture. The ADL values of the whole plant ranged among 6.5 to 12.4%, with lowest values for the M-734 hybrid sowed in December and C-11 hybrid sowed in October. The M-734 hybrid sowed in December has better relationship among phenology, yield and bromatological composition, traits required for the making of high quality silage.

  14. 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).

  15. 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 ...

  16. The genetic architecture of UV floral patterning in sunflower.

    Science.gov (United States)

    Moyers, Brook T; Owens, Gregory L; Baute, Gregory J; Rieseberg, Loren H

    2017-07-01

    The patterning of floral ultraviolet (UV) pigmentation varies both intra- and interspecifically in sunflowers and many other plant species, impacts pollinator attraction, and can be critical to reproductive success and crop yields. However, the genetic basis for variation in UV patterning is largely unknown. This study examines the genetic architecture for proportional and absolute size of the UV bullseye in Helianthus argophyllus , a close relative of the domesticated sunflower. A camera modified to capture UV light (320-380 nm) was used to phenotype floral UV patterning in an F 2 mapping population, then quantitative trait loci (QTL) were identified using genotyping-by-sequencing and linkage mapping. The ability of these QTL to predict the UV patterning of natural population individuals was also assessed. Proportional UV pigmentation is additively controlled by six moderate effect QTL that are predictive of this phenotype in natural populations. In contrast, UV bullseye size is controlled by a single large effect QTL that also controls flowerhead size and co-localizes with a major flowering time QTL in Helianthus . The co-localization of the UV bullseye size QTL, flowerhead size QTL and a previously known flowering time QTL may indicate a single highly pleiotropic locus or several closely linked loci, which could inhibit UV bullseye size from responding to selection without change in correlated characters. The genetic architecture of proportional UV pigmentation is relatively simple and different from that of UV bullseye size, and so should be able to respond to natural or artificial selection independently.

  17. Breeding of Herbicide-resistant Parent Material for Oil Sunflower%油用向日葵抗除草剂亲本材料选育研究

    Institute of Scientific and Technical Information of China (English)

    李慧英; 孙敏; 刘壮; 牛庆杰; 于学鹏; 张雷; 张曼; 薛丽静

    2015-01-01

    The sunflower CMS lines and restorer lines herbicide-resistant parent material were developed by using 6 oil-seed sunflower hybrids. The new combinations developed by using them are also herbicide-resistant. These hybrids can be used in sunflower production for saving labor, efficiency and increasing yield. At the same time, they will be prevented from phy-totoxicity of previous crop herbicide.%利用外引的6个杂交种选育抗杀阔叶除草剂的油用型不育系和恢复系亲本材料,用其配制的新组合对同型除草剂同样具有抗药性,应用于生产可省工、高效、增产,同时可减少前茬除草剂药害。

  18. 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.

  19. 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.

  20. 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.

  1. Plant population and weeds influence stalk insects, soil moisture, and yield in rainfed sunflowers

    Institute of Scientific and Technical Information of China (English)

    JAWWAD A. QURESHI; PHILLIP W. STAHLMAN; J. P. MICHAUD

    2007-01-01

    Insect infestation, soil moisture, and yield were examined in populations of≈ 33 140 plants/ha (low) and ≈ 40 340 plants/ha (high) of an oilseed sunflower, Helianthus annuus L, cv. ' Triumph 660CL' with two levels of weediness. Less weedy plots resulted from the application of herbicide combination of S-metolachlor and sulfentrazone, whereas more weedy plots resulted from application of sulfentrazone alone. Among the 12 weed species recorded, neither plant numbers nor biomass differed between crop plant densities.Larvae of the stalk-boring insects Cylindrocopturus adspersus (Coleoptera: Curculionidae) and Mordellistena sp. (Coleoptera: Mordellidae) were less abundant in high density sunflowers, ostensibly due to reduced plant size. However, the same effect was not observed for Dectes texanus (Coleoptera: Cerambycidae) or Pelochrista womanana (Lepidoptera:Tortricidae), two other stalk-boring insects. Soil moisture was highest in low density and lowest in the high density sunflowers that were less weedy. Stalk circumference, head diameter, and seed weight were reduced for sunflower plants with short interplant distances (mean = 20 cm apart) compared to plants with long interplant distances (mean = 46 cm apart).These three variables were greater in less weedy plots compared with more weedy plots and positively correlated with interplant distance. Yields on a per-hectare basis paralleled those on a per-plant basis but were not different among treatments. The agronomic implications of planting density are discussed in the context of weed and insect management.

  2. Sunflower Array Antenna with Adjustable Density Taper

    NARCIS (Netherlands)

    Viganó, M.C.; Toso, G.; Caille, G.; Mangenot, C.; Lager, I.E.

    2009-01-01

    A deterministic procedure to design a nonperiodic planar array radiating a rotationally symmetric pencil beam pattern with an adjustable sidelobe level is proposed. The elements positions are derived by modifying the peculiar locations of the sunflower seeds in such a way that the corresponding spat

  3. Physical properties of sunflower grains after drying

    Directory of Open Access Journals (Sweden)

    Paulo Carteri Coradi

    2015-12-01

    Full Text Available The knowledge of the physical properties of the grains is important for the optimization of post-harvest operations. This study aimed to evaluate the effects of convective drying with different air temperatures (45, 55, 65 and 75 °C the physical properties of sunflower seeds. The drying sunflower grains was performed in convection oven with forced air. In natural conditions, samples of 5 kg of pellets were used for each repetition drying. During the drying process, the grains samples were weighed periodically until they reach 10% (wet basis, w.b., then were subjected to evaluations of physical properties. According to the results it was observed that the porosity, apparent density, thousand kernel weight to the drag coefficient, roundness, sphericity and width of sunflower seed did not change with increasing temperature drying air. It was concluded that the drying air temperatures of 45 °C and 55 retained the initial physical characteristics of sunflower seeds. The temperature of the drying air of 75 °C had greater influence on changes in volumetric shrinkage of the grains.

  4. 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...

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. Potential of sunflower, castor bean, common buckwheat and vetiver as lead phytoaccumulators

    Directory of Open Access Journals (Sweden)

    Jailson do C. Alves

    2016-03-01

    Full Text Available ABSTRACT Studies concerning the tolerance, absorption and distribution of heavy metals in plants are essential for the success of phytoremediation programs. The present study was carried out in order to evaluate the potential of the sunflower, castor bean, common buckwheat and vetiver as lead phytoaccumulators. The species were grown in nutrient solution containing increasing doses of Pb (0, 50, 100, 200 and 400 mg L-1 during a 30-day exposure period. A completely randomized split-plot design was used, with a 4 x 5 factorial and three replicates. Significant reductions of dry matter of the root, shoot and whole plant were found in the all species under study as a function of the increased Pb doses. Vetiver showed higher tolerance to Pb contamination; sunflower and castor bean had intermediate tolerance and the common buckwheat proved to be the most sensitive species. The concentration and total content of Pb in plant compartments were significantly affected by the increased Pb doses in solution, and higher accumulation of this element was observed, in general, in the roots of the studied species. Common buckwheat proved to be not much promising for Pb-phytoremediation programs; sunflower showed potential for Pb phytoextraction and castor bean and vetiver were the most appropriate for Pb phytostabilization.

  11. 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

  12. Growth under elevated atmospheric CO(2) concentration accelerates leaf senescence in sunflower (Helianthus annuus L.) plants.

    Science.gov (United States)

    de la Mata, Lourdes; Cabello, Purificación; de la Haba, Purificación; Agüera, Eloísa

    2012-09-15

    Some morphogenetic and metabolic processes were sensitive to a high atmospheric CO(2) concentration during sunflower primary leaf ontogeny. Young leaves of sunflower plants growing under elevated CO(2) concentration exhibited increased growth, as reflected by the high specific leaf mass referred to as dry weight in young leaves (16 days). The content of photosynthetic pigments decreased with leaf development, especially in plants grown under elevated CO(2) concentrations, suggesting that high CO(2) accelerates chlorophyll degradation, and also possibly leaf senescence. Elevated CO(2) concentration increased the oxidative stress in sunflower plants by increasing H(2)O(2) levels and decreasing activity of antioxidant enzymes such as catalase and ascorbate peroxidase. The loss of plant defenses probably increases the concentration of reactive oxygen species in the chloroplast, decreasing the photosynthetic pigment content as a result. Elevated CO(2) concentration was found to boost photosynthetic CO(2) fixation, especially in young leaves. High CO(2) also increased the starch and soluble sugar contents (glucose and fructose) and the C/N ratio during sunflower primary leaf development. At the beginning of senescence, we observed a strong increase in the hexoses to sucrose ratio that was especially marked at high CO(2) concentration. These results indicate that elevated CO(2) concentration could promote leaf senescence in sunflower plants by affecting the soluble sugar levels, the C/N ratio and the oxidative status during leaf ontogeny. It is likely that systemic signals produced in plants grown with elevated CO(2), lead to early senescence and a higher oxidation state of the cells of these plant leaves.

  13. [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.

  14. 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.

  15. Full-length sequence analysis of a distinct isolate of Bidens mottle virus infecting sunflower in Taiwan.

    Science.gov (United States)

    Liao, J Y; Hu, Chung-Chi; Chen, C C; Chang, C H; Deng, T C

    2009-01-01

    The full-length genome of a potyvirus, previously known as sunflower chlorotic spot virus isolate SF-1 (SCSV-SF-1) which causes novel symptoms on sunflowers (Helianthus annuus), was sequenced and analyzed. The genome of SCSV-SF-1 is 9,741 nucleotides long, encoding a polyprotein of 3,071 amino acids containing the consensus motifs of potyviruses. Sequence comparison revealed that the 3'-terminus of SCSV-SF-1 shared over 96% similarities with isolates of Bidens mottle virus (BiMoV). However, SCSV-SF-1 has a very narrow host range, excluding the diagnostic host species for BiMoV, Bidens pilosa and Zinnia elegans. Therefore, SCSV-SF-1 is a distinct isolate of BiMoV. This is the first report of the full-length nucleotide sequence of BiMoV infecting sunflower in Taiwan.

  16. The role of biotechnologies in the development of sunflower cultures in the world

    OpenAIRE

    Durante Mauro; Vannozzi Gian Paolo; Pugliesi Claudio; Bernardi Rodolfo

    2002-01-01

    Sunflower improvement by conventional breeding is severely restricted by the availability of a rather limited gene pool owing to natural incompatibilities, even between related species, and by the time scale of most breeding programs. Therefore, much attention has been directed recently to the newly emerging and novel technologies of plant cell and molecular biology that provide a powerful means to supplement and complement the traditional methods of plant improvement. The concept of DNA-base...

  17. 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

  18. 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.

  19. 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...

  20. Honey bee visitation to sunflower: effects on pollination and plant genotype

    Directory of Open Access Journals (Sweden)

    Emerson Dechechi Chambó

    2011-12-01

    Full Text Available Sunflower (Helianthus annuus L. is an allogamic plant, which needs insects on flowering, especially the honeybees for seed production. Collecting nectar and pollen by honeybees in agricultural crops is essential to apiculture, as well as a better understanding of plant biology. The foraging behavior of Africanized Apis mellifera L. (Hymenoptera, Apidae and its efficiency of pollination on seed yield of sunflower genotypes (open pollination and restricted pollination were evaluated. There were peaks of visits by A. mellifera for nectar collection on the 2nd and 3rd flowering days between 7h00 and 8h30. The average density of A. mellifera during increased visitation ranged from 2.27 to 2.94 bees per capitulum. Nectar collecting bees were more frequent (2.28 bees per capitulum than pollen collecting (0.40 bees per capitulum. On the 3rd flowering day, Helio 360 and Aguará hybrids had higher (p ≤ 0.05 number of bee visits per flower head than the other genotypes. Seed yield was 43 % higher (p ≤ 0.05 from sunflower plants that were visited by pollinator-insects compared with plants restricted to pollinators.

  1. 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.

  2. Sunflower Array Antenna with Adjustable Density Taper

    OpenAIRE

    Maria Carolina Viganó; Giovanni Toso; Gerard Caille; Cyril Mangenot; Lager, Ioan E.

    2009-01-01

    A deterministic procedure to design a nonperiodic planar array radiating a rotationally symmetric pencil beam pattern with an adjustable sidelobe level is proposed. The elements positions are derived by modifying the peculiar locations of the sunflower seeds in such a way that the corresponding spatial density fits a Taylor amplitude tapering law which guarantees the pattern requirements in terms of beamwidth and sidelobe level. Different configurations, based on a Voronoi cell spatial tessel...

  3. High-oleic sunflower, a new oil component; Die High-Oleic-Sunflower als neue Grundoelkomponente

    Energy Technology Data Exchange (ETDEWEB)

    Botz, O. [Natoil AG, Technopark Luzern (Switzerland)

    2007-07-01

    Achieved results from NATOIL {sup registered} proved that the application of the High-Oleic-Sunflower as a component of a base oil in lubricants is in general feasible. The target goals and properties have been realised with great success. To emphasize are particularly good results in relation to piston cleanliness, oxidative stability as well as fuel economy properties. The central fear that the High-Oleic-Sunflower would not be sufficiently stable concerning oxidation has been clearly refuted in diverse motor tests. The application of the High-Oleic Sunflower and of the here of manufactured esters enables the development of lubricants with much lower viscosity characteristics in comparison to mineral-oil-based lubricants, which may result in the overall reduction of the average drag torque by up to 30%. (orig.)

  4. Expressed Sequence Tags from the oomycete Plasmopara halstedii, an obligate parasite of the sunflower

    Directory of Open Access Journals (Sweden)

    Mouzeyar Said

    2007-12-01

    Full Text Available Abstract Background Sunflower downy mildew is a major disease caused by the obligatory biotrophic oomycete Plasmopara halstedii. Little is known about the molecular mechanisms underlying its pathogenicity. In this study we used a genomics approach to gain a first insight into the transcriptome of P. halstedii. Results To identify genes from the obligatory biotrophic oomycete Plasmopara halstedii that are expressed during infection in sunflower (Helianthus annuus L. we employed the suppression subtraction hybridization (SSH method from sunflower seedlings infected by P. halstedii. Using this method and random sequencing of clones, a total of 602 expressed sequence tags (ESTs corresponding to 230 unique sequence sets were identified. To determine the origin of the unisequences, PCR primers were designed to amplify these gene fragments from genomic DNA isolated either from P. halstedii sporangia or from Helianthus annuus. Only 145 nonredundant ESTs which correspond to a total of 373 ESTs (67.7% proved to be derived from P. halstedii genes and that are expressed during infection in sunflower. A set of 87 nonredundant sequences were identified as showing matches to sequences deposited in public databases. Nevertheless, about 7% of the ESTs seem to be unique to P. halstedii without any homolog in any public database. Conclusion A summary of the assignment of nonredundant ESTs to functional categories as well as their relative abundance is listed and discussed. Annotation of the ESTs revealed a number of genes that could function in virulence. We provide a first glimpse into the gene content of P. halstedii. These resources should accelerate research on this important pathogen.

  5. Effect of Micronutrients on Quality and Quantity Characteristics Two Varieties of Sunflower

    Science.gov (United States)

    Rahimi, Mohammad Mehdi; Yadegari, Mehrab; Aeinehband, Amir

    2008-01-01

    This experiment was evaluated in research station of Fars in 2003 in a clay texture in order to test the effect of micronutrients on quality and quantity characteristics of 2 Varieties of Sunflower in Arsanjan by using split plot design with randomized complete blocks base design and 4 replication. Main-plot consisted of 2 Sunflower varieties: Golshid hybrid and Record variety. Sub-plot consisted of five fertilizer treatments: (T1 = NPKMg), (T2 = NPKMg+Fe), (T3 = NPKMgFe+B), (T4 = NPKMgFe B+Mn), (T5 = NPKgFeBMn+Zn). Results show that: 1. Variety factor like pulmetic acid, harvest index and cap diameter had a full significant effect, but linoleic acid, oleic acid, seed yield per cap, oil yield per ha, biologic yield per bush and the weight of 1000 seeds had a less significant effect. 2. The influence of Fertilizer treatments factor on Percentage of Linoleic acid, Oleic acid, Pulmetic acid, Staric acid, seed yield per, Percentage of oil, oil yield per hectare, (HI) and weight of 1000 seeds characters had a significant effect. 3. Golsid hybrid was realized better than record variety. 4. According to this experiment Fourth fertilizers treatments in Golshid hybrid was realized the best interaction effect between two factors of varieties and fertilizer treatments.

  6. 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.

  7. 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...

  8. 15e CONFERENCE INTERNATIONALE TOURNESOL Sunflower ecophysiology: some unresolved issues*

    Directory of Open Access Journals (Sweden)

    Hall Antonio J.

    2001-01-01

    Full Text Available Major unresolved issues in sunflower ecophysiology constrain efforts to improve crop modelling, management, genetic analysis and breeding. Three issues are used here to illustrate this point. Firstly, much of the work on the duration of the emergence to flowering phase has considered the phase as a whole. It is argued that a more detailed analysis based on sub-phases is required, particularly in view of possible intraspecific variability in the durations of the basic vegetative and juvenile phases and evidence that photoperiod responses before, during and after floral initiation may differ between genotypes and even be of opposite sign for the same genotype. Secondly,contrasting responses of grain oil proportion to manipulation of plant population density and incident radiation appear to be linked to variations in kernel oil proportion rather than to kernel: hull ratio, and responses of grain oil proportion to changes in sowing date seem to have a similar origin. More effort should be focused on understanding the controls of oil mass per kernel. It is speculated that there may be a genotype-dependent limit to this variable. A third unresolved issue relates to the nature and strength of the linkage between post-anthesis stay-green and leaf photosynthetic functionality. These variables are poorly related during pre-anthesis senescence of leaves in the lower portion of closed canopies, and for sunflower this linkage appears much weaker than in other crop species. Current interest in post-anthesis stay-green as a possibly useful crop attribute requires clarification of this uncertainty.

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

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    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

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

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    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.

  11. 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.

  12. 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.

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

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    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.

  14. 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.

  15. 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

  16. 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

  17. Composição química, digestibilidade e cinética de degradação ruminal das silagens de híbridos de girassol em diferentes épocas de semeadura Effects of sowing dates on chemical composition, digestibility and ruminal degradation kinetics of silages from sunflower hybrids

    Directory of Open Access Journals (Sweden)

    Renius Mello

    2006-08-01

    Full Text Available Objetivou-se estimar o valor nutritivo das silagens de quatro híbridos de girassol - Rumbosol-91 (forrageiro, M-734 (duplo-propósito, C-11 (duplo-propósito e BRS-191 (granífero - semeados em três épocas: outubro (antecipada, novembro (normal e dezembro (tardia - por meio de análises químicas, da digestibilidade e da cinética de degradação ruminal. O delineamento experimental foi em blocos ao acaso, com arranjo fatorial 4 x 3 (quatro híbridos x três épocas de semeadura e três repetições. Os teores de MS variaram de 23,2 a 43,0%; o pH, de 4,0 a 5,1; e o N-NH3%/NT, de 5,3 a 16,8%. Os teores de CZ oscilaram de 6,8 a 8,8% e aumentaram da semeadura em outubro para dezembro. O Rumbosol-91 apresentou teores menores de EE e maiores de N na parede celular, de N indisponível e de carboidratos totais (CHOT. Os teores de PB aumentaram e os de CHOT diminuíram de outubro para dezembro. A semeadura de novembro e o C-11 apresentaram menores teores de FDN, FDNcp e FDA. O C-11 semeado em novembro apresentou menor teor de LDA. A semeadura de outubro e o Rumbosol-91 tiveram maior proporção de LDA%/FDN. O Rumbosol-91 apresentou maior DIVMS e DIVFDN. A semeadura de novembro e os híbridos C-11 e M-734 apresentaram maior teor de NDT. O desaparecimento da MS pode ser representado por um único perfil de degradação. A proporção de FDN indegradável (I aumentou da semeadura em outubro para dezembro, com maiores valores para o BRS-191 semeado em dezembro. A extensão (Vf1 e a taxa (k1 de degradação da fração solúvel de rápida digestão diminuíram da semeadura em outubro para dezembro, com maiores valores para o Rumbosol-91 semeado em outubro. A relação entre análise química, digestibilidade, NDT e cinética de degradação ruminal foi melhor para os híbridos M-734 e C-11 semeados em novembro.The objective of this trial was to estimate chemical composition, digestibility and ruminal degradation kinetics of silages from four sunflower

  18. A Partial Equilibrium Analysis of Sunflower Market in Turkey

    Directory of Open Access Journals (Sweden)

    B. Miran

    2006-09-01

    Full Text Available Sunflower oil is the most preferred vegetable oil in Turkey. 35% of total consumption of vegetable oil issunflower oil. Sunflower seed import is approximately 500-650 thousand tons while sunflower seedproduction is 800-850 thousand tons in the last years. The main objective of this study is to determine thereasons of deficiency of vegetable oil in Turkey and to suggest some solutions. For this objective, theprospective situation and the market structure of sunflower seed in Turkey has estimated. “One productpartial equilibrium analysis” has been used to estimate the future market structure of sunflower seed. Asimulation model from 2003 to 2015 has been created with partial equilibrium analysis. Turkey is a netimporter of vegetable oils. Sunflower seed import is approximately 300 thousand tons while crude oil importis approximately 180 thousand tons in 2002. According to the results of simulation model, Turkey willcontinue to be a net importer for sunflower and other oil seeds. It has been estimated that the sunflower seedimport will be approximately 1 million tons and crude oil import will be approximately 400 thousand tons atend of the simulation period (2003-2015.

  19. Morphology and networks of sunflower wax crystals in organogel

    Science.gov (United States)

    Plant waxes are considered as promising alternatives to unhealthy solid fats such as trans fats and saturated fats in structured food products including margarines and spreads. Sunflower wax is of a great interest due to its strong gelling ability. Morphology of sunflower wax crystals formed in soyb...

  20. Crystal morphology of sunflower wax in soybean oil organogel

    Science.gov (United States)

    While sunflower wax has been recognized as an excellent organogelator for edible oil, the detailed morphology of sunflower wax crystals formed in an edible oil organogel has not been fully understood. In this study, polarized light microscopy, phase contrast microscopy, scanning electron microscopy ...

  1. Evaluating perennial sunflower for wildlife and food uses

    Science.gov (United States)

    The objective of this research is to use current genetics and plant breeding techniques to introgress genes for perennial habit from Helianthus tuberosus L. (2n=6x=102) into domesticated sunflower (Helianthus annuus L., 2n=2x=34). H. tuberosusis part of the secondary gene pool of sunflower and has b...

  2. Consumptive Water Use and Crop Coefficients of Irrigated Sunflower

    Science.gov (United States)

    In semi-arid environments, the use of irrigation is necessary for sunflower production to reach its maximum potential. The aim of this study was to quantify the consumptive water use and crop coefficients of irrigated sunflower (Helianthus annuus L.) without soil water limitations during two growing...

  3. Sunflower water productivity in four Great Plains soils

    Science.gov (United States)

    Sunflower (Helianthus annuus L.) is a drought-adapted crop whose short growing season reduces irrigation requirements, makes it ideal for regions with limited irrigation water supplies. Our objectives were to a) evaluate the yield (Y) potential of sunflower under full and deficit irrigation (IR) b)...

  4. 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

  5. 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...

  6. 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 ...

  7. 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...

  8. SUNflower +6 : development and application of a footprint methodology for the SUNflower +6 countries.

    NARCIS (Netherlands)

    Morsink, P. Oppe, S. Reurings, M. & Wegman, F.C.M.

    2006-01-01

    Progress in traffic safety is the result of many efforts, starting with political decisions, the development of safety plans and safety actions and their implementation. This report explores ways of presenting information from the SUNflower+6 countries in such a way that it shows how the interaction

  9. SUNflower +6 : development and application of a footprint methodology for the SUNflower +6 countries.

    NARCIS (Netherlands)

    Morsink, P. Oppe, S. Reurings, M. & Wegman, F.C.M.

    2006-01-01

    Progress in traffic safety is the result of many efforts, starting with political decisions, the development of safety plans and safety actions and their implementation. This report explores ways of presenting information from the SUNflower+6 countries in such a way that it shows how the interaction

  10. Sunflower stalks as adsorbents for color removal from textile wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Sun, G.; Xu, X. [Univ. of California, Davis, CA (United States). Div. of Textiles and Clothing

    1997-03-01

    Sunflower stalks as adsorbents for two basic dyes (Methylene Blue and Basic Red 9) and two direct dyes (Congo Red and Direct Blue 71) in aqueous solutions were studied with equilibrium isotherms and kinetic adsorptions. The maximum adsorptions of two basic dyes on sunflower stalks are very high, i.e., 205 and 317 mg/g for Methylene Blue and Basic Red 9, respectively. The two direct dyes have relatively lower adsorption on sunflower stalks. The adsorptive behaviors of sunflower stalk components are different. The pith, which is the soft and porous material in the center of stalks, has twice the adsorptive capacity of the skin. Particle sizes of sunflower stalks also affect the adsorption of dyes. The adsorption rates of two basic dyestuffs are much higher than that of the direct dyes. Within 30 min about 80% basic dyes were removed from the solutions.

  11. Industrial frying trials with high oleic sunflower oil

    Directory of Open Access Journals (Sweden)

    Niemelä, J. R.K.

    1996-04-01

    Full Text Available High oleic sunflower oil has been developed for some special purposes where a good oxidation stability is needed and a healthy fatty acid profile is preferred. The oil is especially suitable for deep fat frying. These industrial frying trials with high oleic sunflower oil were part of the AIR-project CT 920687 "Utilisation of Sunflower Oils in Industrial Frying Operations". High oleic sunflower oil (HOSO was tested against the traditional oils and fats in two industrial deep fat frying applications, namely crisps and prefried frozen french fries. The frying trials took place in Raisio Groups factories in Pyhanta and Vihanti, Finland in 1993 and 1994. According to the trials, high oleic sunflower oil is very suitable for deep fat frying. Problems occurred when a hard fat was substituted for a liquid oil in the preparation of prefrozen French Fries. These problems could be partly overcome by adjustments in the processing line.

  12. 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.

  13. 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.

  14. Interrelationship of pollination conditions, fertilization and sunflower seed yield

    Directory of Open Access Journals (Sweden)

    Joksimović Jovan

    2005-01-01

    Full Text Available Four commercially important sunflower hybrids (NS-H-45, NS-H-l 11, NS-H-702 and Velja and their parental components (Ha-74B, Ha-98B, CMS-3-8B, Ha-26B, RHA-583, RHA-R-PI-2/1 and RHA-113N were used over a period of two years to study the following traits: disk flower corolla length, nectar content, pollen viability, bee visitation, fertilization percentage and seed yield. Relations among the traits were determined by path coefficient analysis. The simple correlation coefficients showed that fertilization percentage and bee visitation had a highly significant influence on seed yield. The corolla length had a positive effect on nectar content, while nectar content had a significant negative influence on pollen viability. The highest significant direct influence on seed yield was that of fertilization percentage, while the effect on nectar content on seed yield was negative but not significant. The coefficient of determination was 0.8071.

  15. 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

  16. Sensory properties during storage of crisps and French fries prepared with sunflower oil and high oleic sunflower oil

    NARCIS (Netherlands)

    Gemert, L.J. van

    1996-01-01

    A selected and trained descriptive sensory panel has assessed samples of crisps and French fries prepared on an industrial scale with either sunflower oil (SO) or high oleic sunflower oil (HOSO). Furthermore, crisps have been fried in these oils with or without dimethyl polysiloxane (DMPS). Referenc

  17. Sensory properties during storage of crisps and French fries prepared with sunflower oil and high oleic sunflower oil

    NARCIS (Netherlands)

    Gemert, L.J. van

    1996-01-01

    A selected and trained descriptive sensory panel has assessed samples of crisps and French fries prepared on an industrial scale with either sunflower oil (SO) or high oleic sunflower oil (HOSO). Furthermore, crisps have been fried in these oils with or without dimethyl polysiloxane (DMPS). Referenc

  18. Registration of two confection sunflower germplasm Lines, HA-R10 and HA-R11, Resistant to sunflower rust

    Science.gov (United States)

    Two confection sunflower (Helianthus annuus L.) germplasm lines, HA-R10 (Reg. No.xxx, PI670043) and HA-R11 (Reg. No.xxx, PI670044) were developed by the USDA-ARS Sunflower and Plant Biology Research Unit in collaboration with the North Dakota Agricultural Experiment Station and released December, 20...

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. [Isolation and purification of virus damaging sunflower].

    Science.gov (United States)

    Zakusilo, A O; Didenko, L F; Kniazieva, N A; Boĭko, A L

    1994-01-01

    A procedure has been developed for purifying intact virus's isolate particles evoking yellow spot mosaic disease in sunflower. Purification of pathogen in 0.1 M sodium phosphate buffer, pH 8.0 containing 0.05 M Na3SO3 and 0.2% 2-mercaptoethanol is used. After first clarification extract was exposed to two cycles of high-speed centrifugation and fractionated in linear 10-40% (wt vol-1) sucrose density gradient. Virus was recovered from appropriate fractions after dialysis against 0.01 M Na2SO3.

  6. Sunflower cataract: do not forget Wilson's disease.

    Science.gov (United States)

    Litwin, Tomasz; Langwińska-Wośko, Ewa; Dzieżyc, Karolina; Członkowska, Anna

    2015-10-01

    A 41-year-old man with liver cirrhosis of unknown aetiology for 6 years was admitted to our department to confirm the diagnosis of Wilson's disease. He consulted an ophthalmologist who suspected the presence of a sunflower cataract and Kayser-Fleischer ring. At admission, his liver function tests were modestly impaired (Child-Pugh C, 10 pts). Neurological examination was normal, but cognitive functions were mildly impaired. Based on the copper metabolism abnormalities and clinical manifestation, we diagnosed Wilson's disease (Ferenci score, 6 pts) and started treatment with d-penicillamine. Presenting the case we would like to emphasise the significance of the ophthalmological examination in Wilson's disease diagnosis.

  7. Lowering of phytic acid content by enhancement of phytase and acid phosphatase activities during sunflower germination

    Directory of Open Access Journals (Sweden)

    Juliana da Silva Agostini

    2010-08-01

    Full Text Available The objective of this work was to investigate the germination of hybrid sunflowers BRS191 and C11 as a means of lowering phytic acid (PA content by enhancing the activity of endogenous phytase and acid phosphatase. The concentration of PA in hybrid sunflower achenes varied from 2.16 to 2.83g/100g of sample (p O objetivo deste trabalho foi investigar a germinação de girassóis híbridos BRS 191 e C11 com finalidade de reduzir o teor de AF e aumentar as atividades de phytases e fosfatases endógenas. A concentração do AF nos aquênios de girassóis híbridos variou de 2,16 a 2,83 g /100g de amostra (p< 0,005. As atividades de fitases e fosfatases de girassóis BRS191 e C11 foram elevadas no 4º e 5º dia de germinação, respectivamente, com liberação do fósforo necessário para o desenvolvimento da semente. Estes resultados indicam que o AF do girassol hibrido reduz e a atividade de phytase aumenta em períodos distintos da germinação, possibilitando assim a aplicação desta enzima no controle do teor de AF em cereais, melhorando o seu valor nutricional.

  8. Impact of Inorganic Arsenicals on Vegetative Growth of Two Pakistani Origins Sunflower Cultivars

    Directory of Open Access Journals (Sweden)

    Muhammad Asif Imran

    2015-01-01

    Full Text Available Inorganic arsenicals impact on vegetative growth of two sunflower (Helianthus annuus L. cultivars (FH-385 as Hybrid 1 and FH-405 as Hybrid 2 was monitored. Various levels of two different sodium salts of arsenic, namely, sodium arsenate (Na2HAsO4·7H2O as source of As5+ and sodium arsenite (NaAsO2 as source of As3+, were used to evaluate the effect of arsenic on plant water relation parameters. Significant stress effects were found when arsenic was higher in concentrations (>60 mg/kg soil of both salts as compared to control plants. Genotype FH-405 showed higher levels for shoot and root length, water contents, number of leaves, and leaf area, which indicates well adaptation of this cultivar in arsenic contaminated environment. T5 (100 mg/kg of both salts showed notable stressful impacts as compared to low arsenic concentrations (20, 40 mg/kg and especially control plants in case of all morphophysiological parameters of sunflower cultivars.

  9. Resistance among cultivated sunflower germplasm to stem-infesting pests in the central Great Plains.

    Science.gov (United States)

    Charlet, Laurence D; Aiken, Robert M; Miller, Jerry F; Seiler, Gerald J

    2009-06-01

    A 7-yr field study evaluated 61 oilseed sunflower, Helianthus annuus L., accessions and 31 interspecific crosses for resistance to attack by naturally occurring populations of three stem-infesting pests, the sunflower stem weevil, Cylindrocopturus adspersus (LeConte) (Coleoptera: Curculionidae); a longhorned beetle, Dectes texanus LeConte (Coleoptera: Cerambycidae); and a root boring moth, Pelochrista womonana (Kearfott) (Lepidoptera: Tortricidae), at two locations in the central Great Plains. Germplasm with potential sources of resistance to attack from all three stem-infesting species were revealed. Accessions PI 650558, PI 386230, and PI 431516 were consistent in averaging low densities of stem weevil larvae per stalk among lines tested, and PI 497939 exceeded 25 weevil larvae per stalk in only 1 yr of 5 yr of trials. Several interspecific crosses also had consistently low densities of C. adspersus larvae per stalk. Populations of both D. texanus and P. womonana were variable over years, but differences among the lines tested were evident in many trials, revealing potential for developing resistant germplasm. Four accessions (PI 386230, PI 431542, PI 650497, and PI 650558) had low larval densities of C. adspersus and P. womonana in addition to reduced percentage infestation by D. texanus. Results showed potential for developing resistant genotypes for these pests. The prospect of adding host plant resistance as an integrated pest management (IPM) tactic would provide another tool for reducing economic losses from stem-infesting insect pests of sunflower in the central Great Plains.

  10. Screening of sunflower cultivars for metal phytoextraction in a contaminated field prior to mutagenesis.

    Science.gov (United States)

    Nehnevajova, Erika; Herzig, Rolf; Federer, Guido; Erismann, Karl-Hans; Schwitzguébel, Jean-Paul

    2005-01-01

    Sunflower can be used for the remediation of metal-contaminated soils. Its high biomass production makes this plant species interestingfor phytoextraction and using sunflower oil for a technical purpose may improve the economic balance of phytoremediation. The aim of the present field study was to screen 15 commercial cultivars of Helianthus annuus L. grown on metal-contaminated soil, to find out the variety with the highest metal extraction, which can be further improved by mutation or in vitro breeding procedures. Two different fertilizers (ammonium sulphate and ammonium nitrate) were also used to enhance the bioavailability of metals in soil Highly significant differences were observed within tested varieties for metal accumulation and extraction efficiency. Furthermore, ammonium nitrate increased cadmium extraction, whereas ammonium sulphate enhanced zinc and lead uptake in most tested cultivars. In this field-based sunflower screening, we found enhanced cumulative Cd, Zn, and Pb extraction efficiency by a factor 4.4 for Salut cultivar. We therefore emphasize that prior to any classical breeding or genetic engineering enhancing metal uptake potential, a careful screening of various genotypes should be done to select the cultivar with the naturally highest metal uptake and to start the genetic improvement with the best available plant material.

  11. 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.

  12. Seed size variation and predation of seeds produced by wild and crop-wild sunflowers.

    Science.gov (United States)

    Alexander, H M; Cummings, C L; Kahn, L; Snow, A A

    2001-04-01

    The movement of pollen between crop and wild sunflowers (both Helianthus annuus) has led to concerns about the possible introduction of crop transgenes into wild populations. The persistence of crop traits in wild populations will depend in part on the relative fitness of crop-wild hybrid vs. wild plants. Using seeds from two large experimental field plots, we found that seeds produced by crop-wild plants were twice the size of wild seeds and differed in coloration. Head diameter, date of flowering, identity of mother plant, and levels of predispersal predation explained some variation in mean seed size. We hypothesized that postdispersal vertebrate seed predation would be affected by seed size, with hybrid seeds preferentially eaten. In each of three field trials, significantly more hybrid seeds were eaten (62% of hybrid seed; 42% of wild seed). Within the category of wild seeds, larger seeds were preferentially eaten; however among hybrid seeds, predation was not significantly related to seed size. In this study, differential predation thus reduces hybrid fitness and would presumably slow the spread of transgenes into wild populations.

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. Identification and characterization of contrasting sunflower genotypes to early leaf senescence process combining molecular and physiological studies (Helianthus annuus L.).

    Science.gov (United States)

    López Gialdi, A I; Moschen, S; Villán, C S; López Fernández, M P; Maldonado, S; Paniego, N; Heinz, R A; Fernandez, P

    2016-09-01

    Leaf senescence is a complex mechanism ruled by multiple genetic and environmental variables that affect crop yields. It is the last stage in leaf development, is characterized by an active decline in photosynthetic rate, nutrients recycling and cell death. The aim of this work was to identify contrasting sunflower inbred lines differing in leaf senescence and to deepen the study of this process in sunflower. Ten sunflower genotypes, previously selected by physiological analysis from 150 inbred genotypes, were evaluated under field conditions through physiological, cytological and molecular analysis. The physiological measurement allowed the identification of two contrasting senescence inbred lines, R453 and B481-6, with an increase in yield in the senescence delayed genotype. These findings were confirmed by cytological and molecular analysis using TUNEL, genomic DNA gel electrophoresis, flow sorting and gene expression analysis by qPCR. These results allowed the selection of the two most promising contrasting genotypes, which enables future studies and the identification of new biomarkers associated to early senescence in sunflower. In addition, they allowed the tuning of cytological techniques for a non-model species and its integration with molecular variables.

  19. 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.

  20. Impact of major gene resistance management for sunflower on fitness of Plasmopara halstedii (downy mildew populations

    Directory of Open Access Journals (Sweden)

    Tourvieille de Labrouhe Denis

    2010-01-01

    Full Text Available Changes in virulence of Plasmopara halstedii populations under different major gene (Pl management strategies were studied over 5 years continuous cropping of one sunflower hybrid under netting cages. Strategies were monoculture of forms of the hybrid with 1 gene or with combinations of 2 genes, alternation of different genes, and mixtures of several different forms of the hybrid. Monoculture with single resistance genes led to loss of efficient resistance after 3 years, with high levels of disease and increased variability of the pathogen, whatever the Pl gene used. Combinations of genes, alternation and mixtures gave longer term control of downy mildew. In particular, combinations of resistance genes coming from both female and male parents of the hybrid (such that even impurities had a resistance gene gave the best control and least variation in pathogen virulence. Results are discussed with the object of durable control of downy mildew by all methods available.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Ethiopian soya bean and sunflower value chains : Opportunities and challenges

    NARCIS (Netherlands)

    Wijnands, J.H.M.; Dufera Gurmesa, N.; Lute, J.C.M.; Loo, van E.N.

    2011-01-01

    This report analyses the business opportunities of soya beans and sunflowers. The opportunities are addressed to firms in all levels of the value chain ranging from consumers to farmers in the Ethiopian agriculture.

  7. 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...

  8. Sunflower Beauty Contest : tsvetõ zimoi / Marina Poltavtseva

    Index Scriptorium Estoniae

    Poltavtseva, Marina

    2001-01-01

    Lillekleitide võistlusest Sunflower Beauty Contest Tallinna klubis Decolte. Konkursi idee on florist Tatjana Tridvornovalt. Esimese koha sai Viimsi lilleäri lilleseadjate Meri-Liis Kõivu ja Triinu Põlderi lillekleit "Talvepruut"

  9. Sunflower cake in the diet of Quarter Horses in activity

    Directory of Open Access Journals (Sweden)

    Adalberto Falaschini

    2010-01-01

    Full Text Available The increased availability of sunflower cake, a by-product of oilseed extraction for biodiesel production, prompted us to test the scope of its utilization in the diet of Quarter Horses employed in equestrian shows. We substituted 600 and 1200 g of feed with 300 and 600 g of sunflower cake, respectively, so as to obtain isoproteic and isoenergetic diets. Digestibility evaluation by the AIA method evidenced generally improved nutrient utilization with the lower cake diet (300 g sunflower. The higher cake diet was associated with a reduction in organic matter, protein and ether extract digestibility coefficients. In particular, the trend of the protein coefficients (88.5 - 91.5 - 87.7 for control, 300 and 600 g sunflower cake, respectively was confirmed by higher plasma urea levels.

  10. Sunflower Beauty Contest : tsvetõ zimoi / Marina Poltavtseva

    Index Scriptorium Estoniae

    Poltavtseva, Marina

    2001-01-01

    Lillekleitide võistlusest Sunflower Beauty Contest Tallinna klubis Decolte. Konkursi idee on florist Tatjana Tridvornovalt. Esimese koha sai Viimsi lilleäri lilleseadjate Meri-Liis Kõivu ja Triinu Põlderi lillekleit "Talvepruut"

  11. Mutation breeding in sunflower for resistance to alternaria leaf spot

    OpenAIRE

    de Marcelo Oliveira F.; Tulmann Augusto Neto; Regina Leite M.V.B.C.; Vania Castiglioni B.R.; Arias C.A.A.

    2004-01-01

    Genetic variability for resistance to Alternarla leaf spot disease (Alternaria helianthi) can be induced by radiation or chemical mutagens. The objectives of this study were to create genetic variability in cultivated sunflower and to select lines resistant to Alternaria leaf spot. In the first experiment, sunflower seeds of the genotype HA BR 104 were irradiated with 150 and 165 Gy of gamma rays. Seeds were sown in the field at the Embrapa Soybean experimental station, in Londrina, PR, Brazi...

  12. Oryzanol as natural antioxidant for improving sunflower oil stability.

    Science.gov (United States)

    Sunil, L; Srinivas, P; Prasanth Kumar, P K; Gopala Krishna, A G

    2015-06-01

    Sunflower oil is being made shelf stable by the incorporation of synthetic antioxidants such as tertiary butyl hydroquinone (TBHQ), while natural antioxidants like oryzanol and tocopherols can also be used. The aim of the current investigation was to evaluate the antioxidant effect of natural oryzanol (Oz) concentrate (15.5 % oryzanol) and purified Oz (80 % oryzanol) on oxidative and thermal stability of sunflower oil. Sunflower oil was incorporated with Oz concentrate to provide 0, 0.12, 0.25, 0.50, 0.84, 1.0, 1.60, 2.0, 2.5 and 3.20 % oryzanol in the oil, stored for 5 weeks at 37 °C and oxidative stability was evaluated. It was found that the oryzanol concentrate showed good antioxidant effect with increase in concentration of oryzanol. In another set of experiments, sunflower oil containing purified Oz at 1 % level individually and in combination with 0.1 % α- tocopherol (α-T) was heated at 120 °C for 24 h to evaluate thermal stability. Sunflower oil containing 1 % Oz (80 % purity) showed 98.40 % and sunflower oil containing 1 % Oz and 0.1 % α-T showed 108.75 % antioxidant effect compared to TBHQ taken as 100 %. The study indicated that sunflower oil containing 1 % Oz (80 % purity) and 0.1 % α-T combination provides a synergistic effect in inhibiting primary and secondary products and showed highest thermal stability. SFO containing 1 % Oz added as concentrate also showed good antioxidant effect during storage. Hence, instead of using synthetic antioxidants like TBHQ, we can add natural oryzanol (purified or as concentrate) to sunflower oil to increase its oxidative and thermal stability.

  13. SUNFLOWER HUSKS AS A SOURCE OF FUNCTIONAL FEED ADDITIVES

    OpenAIRE

    Khusid S. B.; Gneush A. N.; Nesterenko E. E.

    2015-01-01

    The article describes the results of the complex feed additive based on sunflower husk, enriched with beer wort with the addition of pumpkin pulp. We have studied the chemical composition of sunflower husk, which is the secondary resource of the processing plant raw material, selected methods of enrichment of this raw material with the help of fungi Trichoderma harzianum. Cellulolytic enzyme preparations on the basis of fungi of the genus Trichoderma for use in agriculture and animal feed pro...

  14. Nutritional and energy values of sunflower cake for broilers

    Directory of Open Access Journals (Sweden)

    Eveline Berwanger

    2014-12-01

    Full Text Available The study aimed to determine the nutritional and energy values of sunflower cake for broilers through two experiments. The first study evaluated the energy values by the method of total excreta collection, using 100 broiler chicks 21–31 days old, divided into five treatments of 0%, 10%, 20%, 30% and 40% inclusion sunflower cake will reference a diet. The second experiment evaluated the influence of the period and the quantity supplied of sunflower cake on digestibility of amino acids by a forcedfeeding technique. Eighteen cockerels were used, divided into three treatments, which consisted of supplying 15 g of sunflower cake, 30 g of sunflower cake (15 g at intervals of 12 hours and 30 g of sunflower cake (15 g at intervals of 24 hours, and an additional six roosters were fasted for correction of metabolic and endogenous losses. The samples were sent for amino acid analysis by HPLC in the Evonik Laboratory (Germany, and chemical and energy analysis to Unioeste Laboratory. The values of apparent metabolizable energy (AME, metabolization coefficient (AMC, apparent metabolizable energy corrected for nitrogen balance (AMEn, metabolization coefficient corrected for nitrogen balance (AMCn for sunflower cake were 2211.68 kcal.kg-1, 2150.54 kcal.kg-1, 45.47% and 44.73%, respectively. The amount of food provided in the feeding method changed the assessment of true digestibility of amino acids (TDCA, and when only 15 g was used, the values of true digestibility coefficients were underestimated. The lysine, histidine and threonine amino acids were at lower TDCA, and arginine and methionine showed the highest TDCA for sunflower cake.

  15. Genetic variance of sunflower yield components - Heliantus annuus L.

    OpenAIRE

    Hladni Nada; Škorić Dragan; Kraljević-Balalić Marija

    2003-01-01

    The main goals of sunflower breeding in Yugoslavia and abroad are increased seed yield and oil content per unit area and increased resistance to diseases, insects and stress conditions via an optimization of plant architecture. In order to determine the mode of inheritance, gene effects and correlations of total leaf number per plant, total leaf area and plant height, six genetically divergent inbred lines of sunflower were subjected to half diallel crosses. Significant differences in mean va...

  16. Association Mapping and the Genomic Consequences of Selection in Sunflower

    OpenAIRE

    Mandel, Jennifer R.; Savithri Nambeesan; Bowers, John E; Laura F Marek; Daniel Ebert; Loren H. Rieseberg; Knapp, Steven J.; Burke, John M.

    2013-01-01

    The combination of large-scale population genomic analyses and trait-based mapping approaches has the potential to provide novel insights into the evolutionary history and genome organization of crop plants. Here, we describe the detailed genotypic and phenotypic analysis of a sunflower (Helianthus annuus L.) association mapping population that captures nearly 90% of the allelic diversity present within the cultivated sunflower germplasm collection. We used these data to characterize overall ...

  17. Quantitative Trait Locus Analysis of the Early Domestication of Sunflower

    OpenAIRE

    David M Wills; Burke, John M.

    2007-01-01

    Genetic analyses of the domestication syndrome have revealed that domestication-related traits typically have a very similar genetic architecture across most crops, being conditioned by a small number of quantitative trait loci (QTL), each with a relatively large effect on the phenotype. To date, the domestication of sunflower (Helianthus annuus L.) stands as the only counterexample to this pattern. In previous work involving a cross between wild sunflower (also H. annuus) and a highly improv...

  18. THE BIOLOGICAL CYCLE OF SUNFLOWER BROOMRAPE

    Directory of Open Access Journals (Sweden)

    DUCA Maria

    2013-12-01

    Full Text Available Orobanchaceae is a dicot family, which consists of annual and perennial plants distributing from tropical to subarctic regions, predominately in temperate regions. Broomrape (Orobanche cumana Wallr. = Orobanche cernua Loefl. is a parasitic angiosperm that has been causing a great deal of damage to sunflower production in many countries, including Republic of Moldova. This parasitic angiosperm depends entirely on the host for its supply of water and nutrients. A thorough understanding of its biology, including detailed knowledge of the specific mechanisms of parasitism, is needed in order to develop novel control methods. Some main developmental steps are described for the root parasites: seed conditioning and germination, haustorium formation, penetration into host tissues, maturation of the parasite plant, and seed production. All these stages were studied in artificial and natural conditions.

  19. Technical Efficiency of Sunflower Production in Trakya Region by DEA

    Directory of Open Access Journals (Sweden)

    G. Unakitan

    2006-05-01

    Full Text Available The objective of this paper is to determine how efficiently the resources are used in sunflowerproduction in Turkey. The data used in efficiency measurements covers the provinces Tekirdag, Kırklareliand Edirne in Trakya region which is the most important area of sunflower seed production. The productionarea of sunflower is about 307 thousand hectares, 57% of total sunflower sown area in Turkey and theamount of production is 498 thousand metric tons, 62% of the total sunflower production. 197 farmers wereinterviewed face to face to obtain the data. Efficiency measurements are made by means of the DataEnvelopment Analysis (DEA with respect to constant return to scale for each province. The Efficiencyscores is decomposed into pure technical efficiency and scale efficiency for getting more information fromthe measurements. Total sunflower production (kg is used as the output and land (decar; labour (hour,tractor use (hour, nitrogen fertilizer use (kg, seed use (kg and pesticide (kg are considered as the maininputs. Average technical efficiency score covering all the provinces is estimated as 0.672. Although none ofthe provinces produces sunflower efficiently, Tekirdag province is relatively more successful in input use.Tekirdag province has the highest pure technical efficiency and scale efficiency score. Considering all theregions, the reason for inefficiency is not optimal production but not producing a certain output withminimum input. Yield is a factor that increases efficiency.

  20. Torrefaction of residues and by-products from sunflower chain

    Directory of Open Access Journals (Sweden)

    G. Riva

    2013-09-01

    Full Text Available The high heterogeneity of some residual biomasses makes rather difficult their energy use and standardisation is a key aspect for these fuel products. Torrefaction is an interesting process used to improve the quality of ligno-cellulosic biomasses and to achieve standardisation. In the present study torrefaction has been employed on residues and by-products deriving from sunflower production chain, in particular sunflower stalks and oil press cake. The thermal behaviour of materials has been studied at first by thermo-gravimetric analysis in order to identify torrefaction temperatures range. Different residence time and torrefaction temperatures have been employed in a bench top torrefaction reactor afterwards. Analyses of raw and torrefied materials have been carried out to assess the influence of the process. As a consequence of torrefaction, the carbon and ash contents increase while the volatilisation range is reduced making the material more stable and standardised. Mass yield, energy yield and energy densification reach values of about 60 %, 80 % and 1.33 for sunflower stalks and 64 %, 85 % and 1.33 for sunflower oil press cake respectively. As highlighted by results, torrefaction is more interesting for sunflower stalks than oil cake and husks because of the different starting characteristics. Untreated oil cake and husks already show a good high heating value and the eventual torrefaction should be mild. On the contrary for sunflower stalks the process is more useful and could be more severe.

  1. Genetic impact on protein content and hullability of sunflower seeds, and on the quality of sunflower meal

    Directory of Open Access Journals (Sweden)

    Dauguet Sylvie

    2016-03-01

    Full Text Available Sunflower seed quality, in particular the characteristics of hullability and protein content, has a significant impact on the protein content of the resulting meal. Seeds dehulled before crushing produce a meal with a protein content of approximately 36%; without dehulling, the protein content is typically in the range of 27–29%. This study seeks to assess the effect of sunflower variety on hullability and protein content. Genetic effects were studied by means of seed samples obtained from a network of variety evaluation trials undertaken across the production area in France for sunflowers. For both characteristics, significant differences between cultivars were observed; as a consequence, the potential protein content of their dehulled meals also ranged widely (34–44%. Genetic selection, which provides substantial improvements in both oil content and fatty acid composition, should therefore be expected to enhance the quality of sunflower meal.

  2. 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

  3. 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.

  4. Genetic analysis of floral symmetry in Van Gogh's sunflowers reveals independent recruitment of CYCLOIDEA genes in the Asteraceae.

    Directory of Open Access Journals (Sweden)

    Mark A Chapman

    Full Text Available The genetic basis of floral symmetry is a topic of great interest because of its effect on pollinator behavior and, consequently, plant diversification. The Asteraceae, which is the largest family of flowering plants, is an ideal system in which to study this trait, as many species within the family exhibit a compound inflorescence containing both bilaterally symmetric (i.e., zygomorphic and radially symmetric (i.e., actinomorphic florets. In sunflower and related species, the inflorescence is composed of a single whorl of ray florets surrounding multiple whorls of disc florets. We show that in double-flowered (dbl sunflower mutants (in which disc florets develop bilateral symmetry, such as those captured by Vincent van Gogh in his famous nineteenth-century sunflower paintings, an insertion into the promoter region of a CYCLOIDEA (CYC-like gene (HaCYC2c that is normally expressed specifically in WT rays is instead expressed throughout the inflorescence, presumably resulting in the observed loss of actinomorphy. This same gene is mutated in two independent tubular-rayed (tub mutants, though these mutations involve apparently recent transposon insertions, resulting in little or no expression and radialization of the normally zygomorphic ray florets. Interestingly, a phylogenetic analysis of CYC-like genes from across the family suggests that different paralogs of this fascinating gene family have been independently recruited to specify zygomorphy in different species within the Asteraceae.

  5. Genetic analysis of floral symmetry in Van Gogh's sunflowers reveals independent recruitment of CYCLOIDEA genes in the Asteraceae.

    Science.gov (United States)

    Chapman, Mark A; Tang, Shunxue; Draeger, Dörthe; Nambeesan, Savithri; Shaffer, Hunter; Barb, Jessica G; Knapp, Steven J; Burke, John M

    2012-01-01

    The genetic basis of floral symmetry is a topic of great interest because of its effect on pollinator behavior and, consequently, plant diversification. The Asteraceae, which is the largest family of flowering plants, is an ideal system in which to study this trait, as many species within the family exhibit a compound inflorescence containing both bilaterally symmetric (i.e., zygomorphic) and radially symmetric (i.e., actinomorphic) florets. In sunflower and related species, the inflorescence is composed of a single whorl of ray florets surrounding multiple whorls of disc florets. We show that in double-flowered (dbl) sunflower mutants (in which disc florets develop bilateral symmetry), such as those captured by Vincent van Gogh in his famous nineteenth-century sunflower paintings, an insertion into the promoter region of a CYCLOIDEA (CYC)-like gene (HaCYC2c) that is normally expressed specifically in WT rays is instead expressed throughout the inflorescence, presumably resulting in the observed loss of actinomorphy. This same gene is mutated in two independent tubular-rayed (tub) mutants, though these mutations involve apparently recent transposon insertions, resulting in little or no expression and radialization of the normally zygomorphic ray florets. Interestingly, a phylogenetic analysis of CYC-like genes from across the family suggests that different paralogs of this fascinating gene family have been independently recruited to specify zygomorphy in different species within the Asteraceae.

  6. 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...

  7. RESPONSE OF TWO SUNFLOWER (HELIANTHUS ANNUUS L. GENOTYPES TO VA-MYCORRHIZAL INOCULATION AND PHOSPHORUS LEVELS

    Directory of Open Access Journals (Sweden)

    C.P. CHANDRASHEKARA, V.C. PATIL

    1995-01-01

    Full Text Available The performance of two sunflower genotypes (Morden and MSFH-8 with and without VA-mycorrhizal fungi at three P levels (38, 56 and 75 kg P2O5 ha-1 in vertisol of Dharwad was studied to determine the effect of mycorrhizal inoculation on plant growth, yield and P uptake. The results showed that the VAM inoculation increased sunflower yield (14%, total biomass (16%, oil content (3.1% and P uptake (30.5% over uninoculated control. The percent root colonization and chlamydo-spore count decreased with increasing P levels. The total biomass production, seed yield and P uptake of mycorrhizal plants at 38 kg P2O5 ha-1 more than the non-mycorrhizal plants at 75 kg P2O5 ha-1. The biomass and seed yield of mycorrhizal plants at same P level were more than the non-mycorrhizal plants. Mycorrhizal plants of Morden at 38 kg P2O5 ha-1 and MSFH-8 at 56 kg P2O5 ha-1 produced higher seed yield, oil content and total biomass than non-mycorrhizal plants supplied with 75 kg P2O5 ha-1. The results indicated that, VA-mycorrhizal inoculation helps in saving 25 and 50 percent of recommended dose of phosphatic fertilizer (75 kg P2O5 ha-1 in MSFH-8 (single cross hybrid and Morden (open pollinated variety, respectively.

  8. 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.

  9. 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.

  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. 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.

  12. 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.

  13. 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.

  14. History of the race structure of Orobanche cumana and the breeding of sunflower for resistance to this parasitic weed: A review

    Energy Technology Data Exchange (ETDEWEB)

    Molinero-Ruiz, L.; Delavault, P.; Pérez-Vich, B.; Pacureanu-Joita, M.; Bulos, M.; Altieri, E.; Domínguez, J.

    2015-07-01

    Broomrape, caused by Orobanche cumana, has affected sunflowers since the early 20th century in Eastern Europe. Currently, it limits sunflower oil production in Southern and Eastern Europe and in some areas of Asia, causing around 50% seed losses when susceptible hybrids are grown. Covered in this review are aspects such as: biological processes that are common to Orobanche spp. and/or particular to O. cumana in sunflower, genetic resistance and its mechanisms, races of the parasite identified in different countries throughout the time and their increasing virulence, and breeding for resistance to some herbicides as a novel control option. The main purpose is to present an updated and, as far as possible, complete picture of the way both the parasitic weed and its host crop have evolved in time, and how they co-exist in the current agriculture. Additionally, we propose a system for determining the races of the parasite that can be internationally adopted from now. In the context of minimal harmful effects on the environment, changing patterns of land use in farming systems, and global environment changes, the final goal of this work is to provide all those interested in parasites from field crops and their integrated management compiled information on the sunflower – O. cumana system as a case study. (Author)

  15. History of the race structure of Orobanche cumana and the breeding of sunflower for resistance to this parasitic weed: A review

    Directory of Open Access Journals (Sweden)

    Leire Molinero-Ruiz

    2015-12-01

    Full Text Available Broomrape, caused by Orobanche cumana, has affected sunflowers since the early 20th century in Eastern Europe. Currently, it limits sunflower oil production in Southern and Eastern Europe and in some areas of Asia, causing around 50% seed losses when susceptible hybrids are grown. Covered in this review are aspects such as: biological processes that are common to Orobanche spp. and/or particular to O. cumana in sunflower, genetic resistance and its mechanisms, races of the parasite identified in different countries throughout the time and their increasing virulence, and breeding for resistance to some herbicides as a novel control option. The main purpose is to present an updated and, as far as possible, complete picture of the way both the parasitic weed and its host crop have evolved in time, and how they co-exist in the current agriculture. Additionally, we propose a system for determining the races of the parasite that can be internationally adopted from now. In the context of minimal harmful effects on the environment, changing patterns of land use in farming systems, and global environment changes, the final goal of this work is to provide all those interested in parasites from field crops and their integrated management compiled information on the sunflower – O. cumana system as a case study.

  16. 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.

  17. 7 CFR 810.1804 - Grades and grade requirements for sunflower seed.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Grades and grade requirements for sunflower seed. 810... AGRICULTURE OFFICIAL UNITED STATES STANDARDS FOR GRAIN United States Standards for Sunflower Seed Principles Governing the Application of Standards § 810.1804 Grades and grade requirements for sunflower seed....

  18. 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...

  19. Molecular tagging of a novel rust resistance gene R12 in sunflower (Helianthus annuus L.)

    Science.gov (United States)

    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 r...

  20. Remarkable life history polymorphism may be evolving under divergent selection in the silverleaf sunflower.

    Science.gov (United States)

    Moyers, Brook T; Rieseberg, Loren H

    2016-08-01

    Substantial intraspecific variation in life history is rare and potentially a signal of incipient ecological speciation, if variation is driven by geographically heterogenous natural selection. We present the first report of extensive life history polymorphism in Helianthus argophyllus, the silverleaf sunflower, and examine evidence for its evolution by divergent selection. In 18 populations sampled from across the species range and grown in a common garden, most quantitative traits covaried such that individuals could be assigned to two distinct life history syndromes: tall and late flowering with small initial flowerheads, or short and early flowering with larger initial flowerheads. Helianthus argophyllus exhibits regional genetic structure, but this population structure does not closely correspond with patterns of phenotypic variation. The early-flowering syndrome is primarily observed in populations from coastal barrier islands, while populations from the nearby mainland coast, although geographically and genetically close, are primarily late flowering. Additionally, several traits are more differentiated among regions than expected based on neutral genetic divergence (QST  > FST ), including the first principal component score corresponding with life history syndrome. This discordance between patterns of phenotypic and genetic variation suggests that divergent selection is driving genetic differences in life history across the species range. If so, the silverleaf sunflower may be in early stages of ecological speciation. © 2016 John Wiley & Sons Ltd.

  1. The Metabolism of Sunflower Phytoalexins Ayapin and Scopoletin

    Science.gov (United States)

    Tal, Beni; Robeson, David J.

    1986-01-01

    The coumarin phytoalexins ayapin and scopoletin accumulate in longitudinal stem sections of sunflower (Helianthus annuus L., Compositae) following inoculation with fungi both pathogenic (Alternaria helianthi) and nonpathogenic (Helminthosporium carbonum) to this plant. Both compounds were induced more rapidly, and they attained higher levels in tissue inoculated with the heterologous pathogen H. carbonum as compared with the sunflower pathogen A. helianthi. Similarly, scopoletin and ayapin accumulated to comparatively low concentrations following inoculation with a second sunflower pathogen, Phoma macdonaldii. Scopoletin was biosynthesized de novo following inoculation, although levels of its glucoside scopolin exceeded those of the aglucone in both infected and control tissues. Both scopoletin and scopolin were routinely detected in trace amounts in uninoculated tissue. In contrast, ayapin was not detected as a component of uninfected plants. When [14C]scopoletin was supplied to induced sunflower stem sections about 36% of the recovered radioactivity was in the form of ayapin. In vitro studies demonstrated that A. helianthi possessed the ability to rapidly degrade both scopoletin and ayapin, whereas H. carbonum was much less efficient in these traits. The differential degradation of these compounds by phytopathogenic fungi which do not attack sunflower is also discussed. PMID:16664986

  2. Nutritional quality of sunflower seed protein fraction extracted with isopropanol.

    Science.gov (United States)

    Sen, M; Bhattacharyya, D K

    2000-01-01

    This study investigated the nutritional effect of sunflower seed protein fraction (SSPF) extracted with isopropanol on growth, plasma and tissue lipid profile, protein content and erythrocyte membrane lipid profile of rats. Dehulled sunflower seeds were extracted with isopropanol at 50 +/- 1 degree C resulting in a protein fraction (71.5%) with low residual chlorogenic acid (0.07%) and fiber (3.3%) contents. Rats fed the sunflower seed protein fraction had a similar body weight gain and food efficiency ratios in comparison to those fed casein. Rats fed SSPF in contrast had a significantly higher growth and food efficiency ratio than the rats fed sunflower meal (SM), extracted with hexane. However, dietary proteins exerted a separate effect on plasma total cholesterol, low density lipoprotein (LDL)-cholesterol, low density lipoprotein to high density lipoprotein cholesterol (LDL-C/HDL-C) ratio and triglyceride content. Sunflower seed protein fraction resulted in a significant decrease in plasma cholesterol (p < 0.05) and LDL-cholesterol (p < 0.02) levels compared to the casein fed rats. Membrane phospholipid profile also showed a marked variation with the type of dietary protein. Rats fed SSPF and SM did not show much variation in plasma lipids, plasma proteins, liver and brain lipids and membrane phospholipid concentrations. Protein content, liver and brain lipid profile of the groups fed SSPF and casein were comparable, suggesting that the nutritional value of SSPF is better than SM and equivalent to that of casein.

  3. Antioxidative effect of thyme (Thymus vulgaris in sunflower oil

    Directory of Open Access Journals (Sweden)

    Zofia Zaborowska

    2012-09-01

    Full Text Available   Background. Lipid oxidation is a main problem during food processing, storage and consumption leading to losses of quality, stability, safety and nutritive value. Antioxidants have been used to prevent oxidation changes and off – flavor development in food products. Aim of the research was to evaluate antioxidative effect of thyme ethanol extract on sunflower oil during its storage in different temperature conditions. Oil samples were stored in darkness at 4°C, 18°C, 38°C. Material and methods. Samples of thyme (thymus vulgaris were purchased at a local pharmacy in Poznań, Poland and sunflower oil was acquired from a local supermarket. Thyme extract was characterized by total polyphenol content. Antioxidant activity was estimated with use of DPPHand ABTSradicals scavenging methods. Ethanol extract of thyme at 1% level was added to sunflower oil. Peroxide value (PV, anisidine value (AV, totox value (TxV and fatty acids (FA content were taken as parameters for evaluation of effectiveness of thyme extract in stabilization of sunflower oil. Results. High polyphenol content, DPPHand ABTSradicals scavenging activity of ethanol thyme extract were evaluated. Results from different parameters were in agreement with other researchers, suggesting the antioxidant effect of thyme on antioxidant stability. Results show that thyme extract prolonged stability of sunflower oil and it may be a potent antioxidant for its stabilization. Conclusions. Ethanol thyme extract may be used as a natural antioxidant to prolong stability of oils.  

  4. Fracionamento dos carboidratos e proteínas de silagens de milho, sorgo e girassol Fractionation of carbohydrate and protein of corn, sorghum and sunflower silages

    Directory of Open Access Journals (Sweden)

    Renius Mello

    2004-10-01

    Full Text Available O trabalho caracteriza e quantifica as frações dos carboidratos e proteínas de silagens de milho, sorgo e girassol, com a finalidade de disponibilizar dados bromatológicos que possibilitem maximizar o aproveitamento desses alimentos e otimizar o desempenho animal. Foram avaliados dois híbridos de milho (Zea mays, DKB-215 e DKB-344, dois híbridos de sorgo (Sorghum bicolor, Ambar e AG-2005 e dois híbridos de girassol (Helianthus annuus, Rumbosol e M-734. A silagem de girassol apresentou menor valor de carboidratos totais (CT e B2 (celulose e hemicelulose e maior de C (lignina e fibra associada à lignina. A silagem de milho apresentou maior valor de carboidratos não-fibrosos (CNF, A+B1 (açúcares solúveis + amido e pectina e de CT juntamente com a silagem de sorgo, enquanto a de sorgo apresentou maior valor de B2 em função da maior contribuição de colmo. Houve diferença entre híbridos dentro da cultura do girassol para CT, sendo que o Rumbosol obteve maior valor que o M-734, em razão da aptidão dos mesmos, forrageiro e granífero respectivamente. A silagem de girassol apresentou maior valor de proteína bruta (PB e de suas frações. Não foi observada diferença entre híbridos nos valores de PB e de suas frações.This work evaluates and characterizes the carbohydrates and proteins fractions of corn, sorghum and sunflower silages. The purpose was to supply composition data that make it possible to maximize use of foods and optimize animal performance. Two corn (Zea mays hybrids, DKB-215 and DKB-344; sorghum (Sorghum bicolor hybrids, Ambar and AG-2005; and sunflower (Helianthus annuus hybrids, Rumbosol and M-734; were evaluated. Sunflower silage showed the lowest total carbohydrates (TC and B2 (cellulose and hemicelluloses values and the highest content of C (lignin and fiber associated lignin. Corn silages showed higher non-fiber carbohydrates (NFC, A+B1 (soluble sugars + starch and pectin and TC together sorghum silage while

  5. 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

  6. Different leachate phytotreatment systems using sunflowers.

    Science.gov (United States)

    Garbo, Francesco; Lavagnolo, Maria Cristina; Malagoli, Mario; Schiavon, Michela; Cossu, Raffaello

    2017-01-01

    The use of energy crops in the treatment of wastewaters is of increasing interest, particularly in view of the widespread scarcity of water in many countries and the possibility of obtaining renewable fuels of vegetable origin. The aim of this study was to evaluate the feasibility of landfill leachate phytotreatment using sunflowers, particularly as seeds from this crop are suitable for use in biodiesel production. Two different irrigation systems were tested: vertical flow and horizontal subsurface flow, with or without effluent recirculation. Plants were grown in 130L rectangular tanks placed in a special climatic chamber. Leachate irrigated units were submitted to increasing nitrogen concentrations up to 372mgN/L. Leachate was successfully tested as an alternative fertilizer for plants and was not found to inhibit biomass development. The experiment revealed good removal efficiencies for COD (η>50%) up until flowering, while phosphorous removal invariably exceeded 60%. Nitrogen removal rates decreased over time in all experimental units, particularly in vertical flow tanks. In general, horizontal flow units showed the best performances in terms of contaminant removal capacity; the effluent recirculation procedure did not improve performance. Significant evapo-transpiration was observed, particularly in vertical flow units, promoting removal of up to 80% of the inlet irrigation volume.

  7. Circumnutations of sunflower hypocotyls in satellite orbit

    Science.gov (United States)

    Brown, A. H.; Chapman, D. K.; Lewis, R. F.; Venditti, A. L.

    1990-01-01

    The principal objective of the research reported here was to determine whether a plant's periodic growth oscillations, called circumnutations, would persist in the absence of a significant gravitational or inertial force. The definitive experiment was made possible by access to the condition of protracted near weightlessness in an earth satellite. The experiment, performed during the first flight of Spacelab on the National Aeronautics and Space Administration shuttle, Columbia, in November and December, 1983, tested a biophysical model, proposed in 1967, that might account for circumnutation as a gravity-dependent growth response. However, circumnutations were observed in microgravity. They continued for many hours without stimulation by a significant g-force. Therefore, neither a gravitational nor an inertial g-force was an absolute requirement for initiation [correction of initation] or continuation of circumnutation. On average, circumnutation was significantly more vigorous in satellite orbit than on earth-based clinostats. Therefore, at least for sunflower (Helianthus annuus L.) circumnutation, clinostatting is not the functional equivalent of weightlessness.

  8. 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.

  9. Evaluation of suitability of common sunflower (Helianthus annuus L. and Castor bean (Ricinus communis L. in phytoextraction of nickel from contaminated soil

    Directory of Open Access Journals (Sweden)

    Maciej Bosiacki

    2013-09-01

    Full Text Available The main objective of this study was to determine the suitability of sunflower (He­lianthus annuus L. ‘Choco Sun’ and castor bean (Ricinus communis L. ‘Sanguineus Apache’ to phytoextraction of nickel from the soil, as well as evaluation of the tolerance of these species to the increasing concentration of the metal. Potential for phytoextraction of ornamental plants has been studied in two years, pot experiment in the plastic greenhouse when they were grown in mineral soil (which was slightly loamy sand with four levels of nickel: control (native nickel content, 50 mg·dm-3 – increased content, 75 mg·dm-3 – low contamination, and 150 mg·dm-3 – medium contamination. Both species of ornamental plants were tolerant to applied concentrations of nickel, with the exception of sunflower grown in medium contaminated soil by this metal. Sunflower and castor bean are not nickel hyperaccumulators. Assessing their potential for nickel phytoextraction from the soil, it was found that it is not significant. Castor bean produces a greater aboveground mass and as a result uptake of nickel is greater compared to sunflower.

  10. 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.

  11. Transcriptome Analysis of Sunflower Genotypes with Contrasting Oxidative Stress Tolerance Reveals Individual- and Combined- Biotic and Abiotic Stress Tolerance Mechanisms.

    Science.gov (United States)

    Ramu, Vemanna S; Paramanantham, Anjugam; Ramegowda, Venkategowda; Mohan-Raju, Basavaiah; Udayakumar, Makarla; Senthil-Kumar, Muthappa

    2016-01-01

    In nature plants are often simultaneously challenged by different biotic and abiotic stresses. Although the mechanisms underlying plant responses against single stress have been studied considerably, plant tolerance mechanisms under combined stress is not understood. Also, the mechanism used to combat independently and sequentially occurring many number of biotic and abiotic stresses has also not systematically studied. From this context, in this study, we attempted to explore the shared response of sunflower plants to many independent stresses by using meta-analysis of publically available transcriptome data and transcript profiling by quantitative PCR. Further, we have also analyzed the possible role of the genes so identified in contributing to combined stress tolerance. Meta-analysis of transcriptomic data from many abiotic and biotic stresses indicated the common representation of oxidative stress responsive genes. Further, menadione-mediated oxidative stress in sunflower seedlings showed similar pattern of changes in the oxidative stress related genes. Based on this a large scale screening of 55 sunflower genotypes was performed under menadione stress and those contrasting in oxidative stress tolerance were identified. Further to confirm the role of genes identified in individual and combined stress tolerance the contrasting genotypes were individually and simultaneously challenged with few abiotic and biotic stresses. The tolerant hybrid showed reduced levels of stress damage both under combined stress and few independent stresses. Transcript profiling of the genes identified from meta-analysis in the tolerant hybrid also indicated that the selected genes were up-regulated under individual and combined stresses. Our results indicate that menadione-based screening can identify genotypes not only tolerant to multiple number of individual biotic and abiotic stresses, but also the combined stresses.

  12. Physicochemical characteristics of ozonated sunflower oils obtained by different procedures

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, M. F.; Sanchez, Y.; Gomez, M.; Hernandez, F.; Veloso, M. C.; Pereira, P. A.; Mangrich, A. S.; Andrade, J. B.

    2012-07-01

    Two ozonation procedures for sunflower oils at different applied ozone dosages were carried out. Ozone was obtained from medicinal oxygen and from air. Peroxide, acidity, and iodine indexes, along with density, viscosity and antimicrobial activity were determined. The fatty acid compositions of the samples were analyzed using GC. The content of oxygen was determined using an elemental analysis. Electronic Paramagnetic Resonance was used to measure the organic free radicals. The reactions were achieved up to peroxide index values of 658 and 675 mmolequiv kg1 using medicinal oxygen and air for 5 and 8 hours, respectively. The samples of ozonized sunflower oil did not present organic free radicals, which is a very important issue if these oils are to be used as drugs. The ozonation reaction is more rapid with medicinal oxygen (5 hours) than with air (8 hours). Ozonized sunflower oil with oxygen as an ozone source was obtained with high potential for antimicrobial activity. (Author) 34 refs.

  13. Gene effects and combining abilities for oil content in sunflower

    Directory of Open Access Journals (Sweden)

    Jocković Milan

    2014-01-01

    Full Text Available Considering the worldwide importance of sunflower oil, objective of this study was to evaluate gene effects and combining abilities of six sunflower open pollinated varieties. Varieties were crossed according to incomplete diallel method and produced fifteen F1 progenies. Comparing the mean values of F1 progenies to parents mean in most cases superdominance was expressed as a mode of inheritance. Nonetheless, dominance of better parent and partial dominance of better parent were also recorded as a mode of inheritance. GCA/SCA ratio indicated greater importance of non-additive genetic component in oil content expression. The genetic variance analysis showed that dominant component was more important and dominant genes prevailed compared to recessive genes for oil content in sunflower.

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

    Science.gov (United States)

    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

  15. Simple sequence repeat map of the sunflower genome.

    Science.gov (United States)

    Tang, S.; Yu, J.-K.; Slabaugh, B.; Shintani, K.; Knapp, J.

    2002-12-01

    Several independent molecular genetic linkage maps of varying density and completeness have been constructed for cultivated sunflower ( Helianthus annuus L.). Because of the dearth of sequence and probe-specific DNA markers in the public domain, the various genetic maps of sunflower have not been integrated and a single reference map has not emerged. Moreover, comparisons between maps have been confounded by multiple linkage group nomenclatures and the lack of common DNA markers. The goal of the present research was to construct a dense molecular genetic linkage map for sunflower using simple sequence repeat (SSR) markers. First, 879 SSR markers were developed by identifying 1,093 unique SSR sequences in the DNA sequences of 2,033 clones isolated from genomic DNA libraries enriched for (AC)(n) or (AG)(n) and screening 1,000 SSR primer pairs; 579 of the newly developed SSR markers (65.9% of the total) were polymorphic among four elite inbred lines (RHA280, RHA801, PHA and PHB). The genetic map was constructed using 94 RHA280 x RHA801 F(7) recombinant inbred lines (RILs) and 408 polymorphic SSR markers (462 SSR marker loci segregated in the mapping population). Of the latter, 459 coalesced into 17 linkage groups presumably corresponding to the 17 chromosomes in the haploid sunflower genome ( x = 17). The map was 1,368.3-cM long and had a mean density of 3.1 cM per locus. The SSR markers described herein supply a critical mass of DNA markers for constructing genetic maps of sunflower and create the basis for unifying and cross-referencing the multitude of genetic maps developed for wild and cultivated sunflowers.

  16. Optimisation of biodiesel production by sunflower oil transesterification.

    Science.gov (United States)

    Antolín, G; Tinaut, F V; Briceño, Y; Castaño, V; Pérez, C; Ramírez, A I

    2002-06-01

    In this work the transformation process of sunflower oil in order to obtain biodiesel by means of transesterification was studied. Taguchi's methodology was chosen for the optimisation of the most important variables (temperature conditions, reactants proportion and methods of purification), with the purpose of obtaining a high quality biodiesel that fulfils the European pre-legislation with the maximum process yield. Finally, sunflower methyl esters were characterised to test their properties as fuels in diesel engines, such as viscosity, flash point, cold filter plugging point and acid value. Results showed that biodiesel obtained under the optimum conditions is an excellent substitute for fossil fuels.

  17. Evolution of oxidation during storage of crisps and french fries prepared with sunflower oil and high oleic sunflower oil

    Directory of Open Access Journals (Sweden)

    Martín-Polvillo, M.

    1996-04-01

    Full Text Available Storage studies were carried out to define the behaviour of both conventional and high oleic sunflower oils in the industrial preparation of crisps and prefried french fries. Samples of crisps and prefried french fries were stored during 6 and 21 months, respectively, and evolution of oxidation was compared with that of the more saturated fats normally used for the preparation of both products, i.e., palm olein and hydrogenated rapeseed/palm oil mixture. Total oxidation compounds, α-tocopherol content, as well as monomeric and dimeric triglycerides, were quantitated in lipids from fried products after different time periods. Results obtained for crisps at room temperature indicated that only conventional sunflower oil underwent significant oxidation after 6 months. In the case of prefried french fries, maintained at freezer temperatures, no appreciable changes were found after 21 months storage, thus indicating that both sunflower oils can be good alternatives to saturated fats.

  18. 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.

  19. β-carotene in sunflower oil oxidation

    Directory of Open Access Journals (Sweden)

    Yanishlieva, N. V.

    2001-02-01

    Full Text Available The oxidation kinetics of sunflower oil (SO, as well as of pure triacylglycerols of sunflower oil (TGSO in the presence of different concentrations (0.001-0.02 % β-carotene was studied. The process was β-performed at high (kinetic regime and low (diffusion regime oxygen concentrations at room temperature in the dark and under daylight. The results from the oxidation of SO and TGSO at 100ºC in the presence of β-carotene were also presented. It was established that in the antioxidant-free lipid system, the β-carotene did not give any antioxidative protection. It worked as a prooxidant during the oxidation at room temperature and at sufficiently high oxygen concentration, the effect being more pronounced in the dark than under daylight. β-carotene increased the stability of tocopherol-containing SO during its oxidation at room temperature and under daylight. This effect is more strongly expressed in a kinetic regime of oxidation. The synergism of β-carotene with the tocopherols was characterized by the stabilization factor F and the activity A. In the kinetic regime of oxidation F and A varied in the interval F=2.0-6.3, and A =2.7-21.0. In the diffusion regime F=1.3-1.5, and A=1.5-2.8.Se estudió la cinética de oxidación de aceite de girasol (SO, así como la de triacilgliceroles puros de aceite de girasol (TGSO en presencia de diferentes concentraciones (0.001-0.02 % de β- caroteno. El proceso se llevó a cabo a altas (régimen cinético y bajas (régimen de difusión concentraciones de oxígeno a temperatura ambiente con luz natural y en la oscuridad, y se presentan también los resultados de la oxidación de SO y TGSO a 100ºC en presencia de β-caroteno. Los resultados indicaron que en los sistemas lipídicos libres de antioxidantes, el β-caroteno no dio protección antioxidante. Funcionó como prooxidante durante la oxidación a temperatura ambiente y a concentraciones de oxigeno suficientemente elevadas, siendo el efecto m

  20. 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

  1. Using banded sunflower moth (Lepidoptera: Tortricidae) egg density to estimate damage and economic distance in oilseed sunflower.

    Science.gov (United States)

    Mundal, Kirk D; Brewer, Gary J

    2008-06-01

    The banded sunflower moth, Cochylis hospes Walsingham (Lepidoptera: Tortricidae), is an important economic pest of sunflower in the Upper Great Plains of North America. Economic losses due to reductions in seed number, weight, and quality can be significant. Previously, the potential for economic losses were estimated by sampling for adult moths. However, sampling for moths can be difficult and inaccurate. An alternative is to sample for banded sunflower moth eggs, which can be accurately counted in the field by using a binocular 3.5 headband magnifier. The egg counts are used to calculate the economic injury level (EIL) (EIL = C/VWPK), where C is the cost of treatment per unit area, V is the crop market value per unit of weight, W is the slope of the regression between banded sunflower moth egg densities and weight loss per plant, P is a term for plant population per unit area, and K is the control treatment efficacy. Estimates of populations of banded sunflower moth eggs are taken from the center of 400-m spans along all field sides. From these samples and the calculated EIL, a map of the extent of the economically damaging banded sunflower moth population throughout the field is made using economic distance; ED = e ( ( (EIL/E)-1.458)/-0.262). Economic distance estimates the distance an economic population extends into the field interior along a transect from the sampling site. By using egg samples to calculate the EIL and mapping the distribution of economic populations throughout a field, producers can then make more effective pest management decisions.

  2. Biochemistry of high stearic sunflower, a new source of saturated fats.

    Science.gov (United States)

    Salas, Joaquín J; Martínez-Force, Enrique; Harwood, John L; Venegas-Calerón, Mónica; Aznar-Moreno, Jose Antonio; Moreno-Pérez, Antonio J; Ruíz-López, Noemí; Serrano-Vega, María J; Graham, Ian A; Mullen, Robert T; Garcés, Rafael

    2014-07-01

    Fats based on stearic acid could be a healthier alternative to existing oils especially hydrogenated fractions of oils or palm, but only a few non-tropical species produce oils with these characteristics. In this regard, newly developed high stearic oil seed crops could be a future source of fats and hard stocks rich in stearic and oleic fatty acids. These oil crops have been obtained either by breeding and mutagenesis or by suppression of desaturases using RNA interference. The present review depicts the molecular and biochemical bases for the accumulation of stearic acid in sunflower. Moreover, aspects limiting the accumulation of stearate in the seeds of this species are reviewed. This included data obtained from the characterization of genes and enzymes related to fatty acid biosynthesis and triacylglycerol assembly. Future improvements and uses of these oils are also discussed.

  3. Two-stage alkaline-enzymatic pretreatments to enhance biohydrogen production from sunflower stalks.

    Science.gov (United States)

    Monlau, Florian; Trably, Eric; Barakat, Abdellatif; Hamelin, Jérôme; Steyer, Jean-Philippe; Carrere, Hélène

    2013-01-01

    Because of their rich composition in carbohydrates, lignocellulosic residues represent an interesting source of biomass to produce biohydrogen by dark fermentation. Nevertheless, pretreatments should be applied to enhance the solubilization of holocelluloses and increase their further conversion into biohydrogen. The aim of this study was to investigate the effect of thermo-alkaline pretreatment alone and combined with enzymatic hydrolysis to enhance biohydrogen production from sunflower stalks. A low increase of hydrogen potentials from 2.3 ± 0.9 to 4.4 ± 2.6 and 20.6 ± 5.6 mL of H2 g(-1) of volatile solids (VS) was observed with raw sunflower stalks and after thermo-alkaline pretreatment at 55 °C, 24 h, and 4% NaOH and 170 °C, 1 h, and 4% NaOH, respectively. Enzymatic pretreatment alone showed an enhancement of the biohydrogen yields to 30.4 mL of H2 g(-1) of initial VS, whereas it led to 49 and 59.5 mL of H2 g(-1) of initial VS when combined with alkaline pretreatment at 55 and 170 °C, respectively. Interestingly, a diauxic effect was observed with sequential consumption of sugars by the mixed cultures during dark fermentation. Glucose was first consumed, and once glucose was completely exhausted, xylose was used by the microorganisms, mainly related to Clostridium species.

  4. Germination energy as a parameter of seed quality in different sunflower genotypes

    Directory of Open Access Journals (Sweden)

    Mrđa Jelena

    2011-01-01

    Full Text Available Using the standard method, we studied the germination energy of seed of seven different sunflower genotypes (five hybrids and two cytoplasmically male sterile female lines developed at the Institute of Field and Vegetable Crops in Novi Sad. The seed was treated with the fungicides benomil, metalaxyl and fludioxonil and the insecticides thiamethoxam and imidacloprid and kept for a year in a storage facility. Analysis of variance showed that there were highly significant differences among the genotypes, chemical treatments, and storage periods. Highly significant differences were also recorded for all the interactions among the factors studied. On average, the highest germination energy was found in the hybrid H2 (93.45%, whose values of this parameter were highly significantly higher than those of the rest of the genotypes, except for the hybrid H1. Also, each of the hybrids had highly significantly higher germination energy than either of the two lines, and the differences among the hybrids themselves were highly significant. Looking at the chemical treatments, the control had the highest germination energy by a highly significant margin (80.39%. The largest difference was observed in relation to the treatments with insecticides (5.48 and 9.56%. These treatments had highly significantly lower values of germination energy than those involving fungicides. Germination energy increased in the first nine months of storage, peaking at 81.29%. After that, there was a sharp drop to 68.94% after 12 months of storing. Differences among the different storage periods were all highly significant except for that between six and nine months of storage, which was not statistically significant.

  5. 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).

  6. 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.

  7. 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.

  8. Single nucleotide polymorphisms and linkage disequilibrium in sunflower.

    Science.gov (United States)

    Kolkman, Judith M; Berry, Simon T; Leon, Alberto J; Slabaugh, Mary B; Tang, Shunxue; Gao, Wenxiang; Shintani, David K; Burke, John M; Knapp, Steven J

    2007-09-01

    Genetic diversity in modern sunflower (Helianthus annuus L.) cultivars (elite oilseed inbred lines) has been shaped by domestication and breeding bottlenecks and wild and exotic allele introgression(-)the former narrowing and the latter broadening genetic diversity. To assess single nucleotide polymorphism (SNP) frequencies, nucleotide diversity, and linkage disequilibrium (LD) in modern cultivars, alleles were resequenced from 81 genic loci distributed throughout the sunflower genome. DNA polymorphisms were abundant; 1078 SNPs (1/45.7 bp) and 178 insertions-deletions (INDELs) (1/277.0 bp) were identified in 49.4 kbp of DNA/genotype. SNPs were twofold more frequent in noncoding (1/32.1 bp) than coding (1/62.8 bp) sequences. Nucleotide diversity was only slightly lower in inbred lines ( = 0.0094) than wild populations ( = 0.0128). Mean haplotype diversity was 0.74. When extraploted across the genome ( approximately 3500 Mbp), sunflower was predicted to harbor at least 76.4 million common SNPs among modern cultivar alleles. LD decayed more slowly in inbred lines than wild populations (mean LD declined to 0.32 by 5.5 kbp in the former, the maximum physical distance surveyed), a difference attributed to domestication and breeding bottlenecks. SNP frequencies and LD decay are sufficient in modern sunflower cultivars for very high-density genetic mapping and high-resolution association mapping.

  9. Liquid Crystal Formation from Sunflower Oil: Long Term Stability Studies.

    Science.gov (United States)

    da Rocha-Filho, Pedro Alves; Maruno, Mônica; Ferrari, Márcio; Topan, José Fernando

    2016-06-09

    The Brazilian biodiversity offers a multiplicity of raw materials with great potential in cosmetics industry applications. Some vegetable oils and fatty esters increase skin hydration by occlusivity, keeping the skin hydrated and with a shiny appearance. Sunflower (Helianthus annus L.) oil is widely employed in cosmetic emulsions in the form of soaps, creams, moisturizers and skin cleansers due to the presence of polyphenols and its high vitamin E content. Liquid crystals are systems with many applications in both pharmaceutical and cosmetic formulations and are easily detected by microscopy under polarized light due to their birefringence properties. The aim of this research was to develop emulsions from natural sunflower oil for topical uses. Sunflower oil (75.0% w/w) was combined with liquid vaseline (25.0% w/w) employing a natural self-emulsifying base (SEB) derivative. The high temperature of the emulsification process did not influence the antioxidant properties of sunflower oil. Fatty esters were added to cosmetic formulations and extended stability tests were performed to characterize the emulsions. Fatty esters like cetyl palmitate and cetyl ester increase the formation of anisotropic structures. O/W emulsions showed acidic pH values and pseudoplastic behavior. The presence of a lamellar phase was observed after a period of 90 days under different storage conditions.

  10. Liquid Crystal Formation from Sunflower Oil: Long Term Stability Studies

    Directory of Open Access Journals (Sweden)

    Pedro Alves da Rocha-Filho

    2016-06-01

    Full Text Available The Brazilian biodiversity offers a multiplicity of raw materials with great potential in cosmetics industry applications. Some vegetable oils and fatty esters increase skin hydration by occlusivity, keeping the skin hydrated and with a shiny appearance. Sunflower (Helianthus annus L. oil is widely employed in cosmetic emulsions in the form of soaps, creams, moisturizers and skin cleansers due to the presence of polyphenols and its high vitamin E content. Liquid crystals are systems with many applications in both pharmaceutical and cosmetic formulations and are easily detected by microscopy under polarized light due to their birefringence properties. The aim of this research was to develop emulsions from natural sunflower oil for topical uses. Sunflower oil (75.0% w/w was combined with liquid vaseline (25.0% w/w employing a natural self-emulsifying base (SEB derivative. The high temperature of the emulsification process did not influence the antioxidant properties of sunflower oil. Fatty esters were added to cosmetic formulations and extended stability tests were performed to characterize the emulsions. Fatty esters like cetyl palmitate and cetyl ester increase the formation of anisotropic structures. O/W emulsions showed acidic pH values and pseudoplastic behavior. The presence of a lamellar phase was observed after a period of 90 days under different storage conditions.

  11. Glycerol inclusion levels in corn and sunflower silages

    Directory of Open Access Journals (Sweden)

    Adriana de Souza Martins

    2014-10-01

    Full Text Available Due to the seasonal cycle of forage, the use of silage to feed animals provides nutrients throughout the year. However, its quality can be improved with the inclusion of additives and other products. Glycerol is a rich source of energy and present a high efficiency of utilization by animals. The purpose of this work was to evaluate the effect of glycerol inclusion on the chemical and fermentation characteristics of corn and sunflower silages. Two silage sources (maize and sunflower were used and four levels of glycerol inclusion (0, 15, 30 and 45% based on dry matter were carried out. The experimental design was completely randomized in a 2 x 4 factorial arrangement with five replications. The pH values and chemical composition of corn and sunflower silages were determined. In both silages there was increment of dry matter, non-fiber carbohydrates and total digestible nutrients (TDN added to a reduction of crude protein, neutral detergent fiber and acid detergent fiber due to the glycerol inclusion. The corn silage required 45% glycerol to achieve the TDN level of the sunflower silage. The glycerol addition contributed to the increase in the nutritional value, offsetting loss of quality in the ensiling process.

  12. Single Nucleotide Polymorphisms and Linkage Disequilibrium in Sunflower

    Science.gov (United States)

    Kolkman, Judith M.; Berry, Simon T.; Leon, Alberto J.; Slabaugh, Mary B.; Tang, Shunxue; Gao, Wenxiang; Shintani, David K.; Burke, John M.; Knapp, Steven J.

    2007-01-01

    Genetic diversity in modern sunflower (Helianthus annuus L.) cultivars (elite oilseed inbred lines) has been shaped by domestication and breeding bottlenecks and wild and exotic allele introgression−the former narrowing and the latter broadening genetic diversity. To assess single nucleotide polymorphism (SNP) frequencies, nucleotide diversity, and linkage disequilibrium (LD) in modern cultivars, alleles were resequenced from 81 genic loci distributed throughout the sunflower genome. DNA polymorphisms were abundant; 1078 SNPs (1/45.7 bp) and 178 insertions-deletions (INDELs) (1/277.0 bp) were identified in 49.4 kbp of DNA/genotype. SNPs were twofold more frequent in noncoding (1/32.1 bp) than coding (1/62.8 bp) sequences. Nucleotide diversity was only slightly lower in inbred lines (θ = 0.0094) than wild populations (θ = 0.0128). Mean haplotype diversity was 0.74. When extraploted across the genome (∼3500 Mbp), sunflower was predicted to harbor at least 76.4 million common SNPs among modern cultivar alleles. LD decayed more slowly in inbred lines than wild populations (mean LD declined to 0.32 by 5.5 kbp in the former, the maximum physical distance surveyed), a difference attributed to domestication and breeding bottlenecks. SNP frequencies and LD decay are sufficient in modern sunflower cultivars for very high-density genetic mapping and high-resolution association mapping. PMID:17660563

  13. Sunflower proteins : overview of their physicochemical, structural and functional properties

    NARCIS (Netherlands)

    González-Pérez, S.; Vereijken, J.M.

    2007-01-01

    There is increasing worldwide demand for proteins of both animal and plant origin. However, animal proteins are expensive in terms of both market price and environmental impact. Among alternative plant proteins, sunflower seeds are particularly interesting in view of their widespread availability in

  14. A thermoanalytic and kinetic study of sunflower oil

    Directory of Open Access Journals (Sweden)

    Souza A. Gouveia de

    2004-01-01

    Full Text Available Recently, thermoanalytic methods have frequently been used in the characterization of oils and fats. In this work, thermoanalytic and kinetic parameters of sunflower oils, with and without antioxidants, were evaluated using thermogravimetry / derivative thermogravimetry and differential scanning calorimetry. The thermogravimetric profiles for the sunflower oils had similar characteristics, showing a level stretch indicative of stability up to about 200ºC. Thermal decomposition of these oils occurred in three stages, related to the decomposition of polyunsaturated, monounsaturated and saturated fatty acids, respectively. DSC curves show two events that characterize the polymerization and decomposition of triglycerides. The heat capacities of the sunflower oils, obtained by DSC, showed a good correlation and were dependent on the composition of fatty acids. The kinetic parameters, obtained by non isothermal thermogravimetry by the Coats and Redfern, Madhusudanan, Horowitz and Metzger and Van Krevelen methods, were dependent on the antioxidant used. Increasing the frying time produced a decrease in the onset of thermal decomposition temperature in the sunflower oils analyzed.

  15. Turning heads: the biology of solar tracking in sunflower.

    Science.gov (United States)

    Vandenbrink, Joshua P; Brown, Evan A; Harmer, Stacey L; Blackman, Benjamin K

    2014-07-01

    Solar tracking in the common sunflower, Helianthus annuus, is a dramatic example of a diurnal rhythm in plants. During the day, the shoot apex continuously reorients, following the sun's relative position so that the developing heads track from east to west. At night, the reverse happens, and the heads return and face east in anticipation of dawn. This daily cycle dampens and eventually stops at anthesis, after which the sunflower head maintains an easterly orientation. Although shoot apical heliotropism has long been the subject of physiological studies in sunflower, the underlying developmental, cellular, and molecular mechanisms that drive the directional growth and curvature of the stem in response to extrinsic and perhaps intrinsic cues are not known. Furthermore, the ecological functions of solar tracking and the easterly orientation of mature heads have been the subject of significant but unresolved speculation. In this review, we discuss the current state of knowledge about this complex, dynamic trait. Candidate mechanisms that may contribute to daytime and nighttime movement are highlighted, including light signaling, hormonal action, and circadian regulation of growth pathways. The merits of the diverse hypotheses advanced to explain the adaptive significance of heliotropism in sunflower are also considered.

  16. Structure of pectic polysaccharides from sunflower salts-soluble fraction

    Science.gov (United States)

    The manuscript discusses the structural features of pectin polysaccharides extracted from seedless sunflower head residues. The analysis using 1H, 13C and two-dimensional gHSQC NMR showed various numbers of methyl and hydroxyl groups attached to the anomeric carbons in the pectin backbone at differe...

  17. 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

  18. Association mapping and the genomic consequences of selection in sunflower.

    Directory of Open Access Journals (Sweden)

    Jennifer R Mandel

    2013-03-01

    Full Text Available The combination of large-scale population genomic analyses and trait-based mapping approaches has the potential to provide novel insights into the evolutionary history and genome organization of crop plants. Here, we describe the detailed genotypic and phenotypic analysis of a sunflower (Helianthus annuus L. association mapping population that captures nearly 90% of the allelic diversity present within the cultivated sunflower germplasm collection. We used these data to characterize overall patterns of genomic diversity and to perform association analyses on plant architecture (i.e., branching and flowering time, successfully identifying numerous associations underlying these agronomically and evolutionarily important traits. Overall, we found variable levels of linkage disequilibrium (LD across the genome. In general, islands of elevated LD correspond to genomic regions underlying traits that are known to have been targeted by selection during the evolution of cultivated sunflower. In many cases, these regions also showed significantly elevated levels of differentiation between the two major sunflower breeding groups, consistent with the occurrence of divergence due to strong selection. One of these regions, which harbors a major branching locus, spans a surprisingly long genetic interval (ca. 25 cM, indicating the occurrence of an extended selective sweep in an otherwise recombinogenic interval.

  19. Association mapping and the genomic consequences of selection in sunflower.

    Science.gov (United States)

    Mandel, Jennifer R; Nambeesan, Savithri; Bowers, John E; Marek, Laura F; Ebert, Daniel; Rieseberg, Loren H; Knapp, Steven J; Burke, John M

    2013-03-01

    The combination of large-scale population genomic analyses and trait-based mapping approaches has the potential to provide novel insights into the evolutionary history and genome organization of crop plants. Here, we describe the detailed genotypic and phenotypic analysis of a sunflower (Helianthus annuus L.) association mapping population that captures nearly 90% of the allelic diversity present within the cultivated sunflower germplasm collection. We used these data to characterize overall patterns of genomic diversity and to perform association analyses on plant architecture (i.e., branching) and flowering time, successfully identifying numerous associations underlying these agronomically and evolutionarily important traits. Overall, we found variable levels of linkage disequilibrium (LD) across the genome. In general, islands of elevated LD correspond to genomic regions underlying traits that are known to have been targeted by selection during the evolution of cultivated sunflower. In many cases, these regions also showed significantly elevated levels of differentiation between the two major sunflower breeding groups, consistent with the occurrence of divergence due to strong selection. One of these regions, which harbors a major branching locus, spans a surprisingly long genetic interval (ca. 25 cM), indicating the occurrence of an extended selective sweep in an otherwise recombinogenic interval.

  20. Development of insect resistant sunflowers: Updates and challenges

    Science.gov (United States)

    Sunflower Helianthus annuus L. is one of the major oil seed crops grown in the USA. with a highest estimated cultivated acreage of 975,000 acres in North Dakota. Besides diseases and weeds, insects are one of the major causes for yield losses. An average of 9-10% yield losses was attributed to insec...

  1. Sunflower proteins : overview of their physicochemical, structural and functional properties

    NARCIS (Netherlands)

    González-Pérez, S.; Vereijken, J.M.

    2007-01-01

    There is increasing worldwide demand for proteins of both animal and plant origin. However, animal proteins are expensive in terms of both market price and environmental impact. Among alternative plant proteins, sunflower seeds are particularly interesting in view of their widespread availability in

  2. 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

  3. 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

  4. Differential representation of sunflower ESTs in enriched organ-specific cDNA libraries in a small scale sequencing project

    Directory of Open Access Journals (Sweden)

    Heinz Ruth A

    2003-09-01

    Full Text Available Abstract Background Subtractive hybridization methods are valuable tools for identifying differentially regulated genes in a given tissue avoiding redundant sequencing of clones representing the same expressed genes, maximizing detection of low abundant transcripts and thus, affecting the efficiency and cost effectiveness of small scale cDNA sequencing projects aimed to the specific identification of useful genes for breeding purposes. The objective of this work is to evaluate alternative strategies to high-throughput sequencing projects for the identification of novel genes differentially expressed in sunflower as a source of organ-specific genetic markers that can be functionally associated to important traits. Results Differential organ-specific ESTs were generated from leaf, stem, root and flower bud at two developmental stages (R1 and R4. The use of different sources of RNA as tester and driver cDNA for the construction of differential libraries was evaluated as a tool for detection of rare or low abundant transcripts. Organ-specificity ranged from 75 to 100% of non-redundant sequences in the different cDNA libraries. Sequence redundancy varied according to the target and driver cDNA used in each case. The R4 flower cDNA library was the less redundant library with 62% of unique sequences. Out of a total of 919 sequences that were edited and annotated, 318 were non-redundant sequences. Comparison against sequences in public databases showed that 60% of non-redundant sequences showed significant similarity to known sequences. The number of predicted novel genes varied among the different cDNA libraries, ranging from 56% in the R4 flower to 16 % in the R1 flower bud library. Comparison with sunflower ESTs on public databases showed that 197 of non-redundant sequences (60% did not exhibit significant similarity to previously reported sunflower ESTs. This approach helped to successfully isolate a significant number of new reported sequences

  5. 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.

  6. 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.

  7. 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.

  8. 77 FR 5564 - Tehachapi Uplands Multiple Species Habitat Conservation Plan; Kern County, CA

    Science.gov (United States)

    2012-02-03

    ... species that may be taken or otherwise affected by on-going ranch activities and future low density... woolly sunflower (Eriophyllum lanatum var. hallii), Kusche's sandwort (Arenaria macradenia var....

  9. 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”.

  10. 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

  11. SUNflower +6 : a comparative study of the development of road safety in the SUNflower +6 countries : final report.

    NARCIS (Netherlands)

    Wegman, F.C.M. Eksler, V. Hayes, S. Lynam, D. Morsink, P. & Oppe, S. (eds.)

    2006-01-01

    This project has developed the SUNflower approach, originally used to assess Sweden, Great Britain and the Netherlands, for comparing safety programmes and records between countries. The approach has been applied to nine countries, adding three Central European countries (the Czech Republic, Hungary

  12. SUNflower +6 : a comparative study of the development of road safety in the SUNflower +6 countries : final report.

    NARCIS (Netherlands)

    Wegman, F.C.M. Eksler, V. Hayes, S. Lynam, D. Morsink, P. & Oppe, S. (eds.)

    2006-01-01

    This project has developed the SUNflower approach, originally used to assess Sweden, Great Britain and the Netherlands, for comparing safety programmes and records between countries. The approach has been applied to nine countries, adding three Central European countries (the Czech Republic, Hungary

  13. Yield And Yield Characters of Differrent Confectionery Sunflower Varieties in Conditions of Tekirdag

    Directory of Open Access Journals (Sweden)

    Y. Ergen

    2005-09-01

    Full Text Available This research which was performed for the purpose of determining the yield and yield characters of six different kinds confectionery sunflowers in the conditions of Tekirdağ was established in the simulation field at Field Plants Department of Thrace University Tekirdağ Agriculture Faculty. In the research were used, T.T.A.E. 1, T.T.A.E. 2 was hybrid varieties, Kıbrıs, İnegöl Alası, and Tekirdağ was local varieties The field experiments was layout at the randomized complete blocks with four replication.In the experiment, some of the characters related to yield such as the plant height, the head diameter, the weight of 1000 seed, the seed yield, seed lenght, the ratio of hull, ratio of oil and protein were examined. The highest seed yield (364.55 kg/da and the lowest hull ratio (%42.77 were determined at T.T.A.E. 2. The highest protein percentage (%17.18 was found İnegöl Alası and the tallest seed lengths (1.61cm was determined Kıbrıs sort. Through the dual relationship between the characters which were examined, a positive and important correlation was found between yield of seed and the seed lenght (0.624**, important but negative correlation was found between the yield of seed and hull ratio (-0.488*. Important and positive correlation was determined between the protein ratio and the plant height (0.575** and important but negative relation was determined between the weight of the 1000 seed (-0.508* and the hull ratio (-0.488*. As a results of Path Analysis, it was determined that the direct influences of the seed and plant height is especially important for the yield of seed and the protein ratio confectionery sunflowers

  14. Impact of the seed storage time on the quality of cold-pressed sunflower oil

    Directory of Open Access Journals (Sweden)

    Premović Tamara Đ.

    2014-01-01

    Full Text Available The objective of this study was to investigate the impact of seed storage time on the quality of cold-pressed sunflower oil. The quality and oxidative stability of oil was determined in samples of domestic varieties of sunflower hybrid, linoleic type seeds, obtained from fresh seeds and from seeds stored in silo cell for 6 and 12 months at temperature below 30oC and in good ventilation conditions. It was found that the longer storage time of seeds had a negative impact on many quality aspects of the oil, such as flavor, odor and aroma, primarily on the sensory profile. Chemical characteristics and oxidative stability of oil were also influenced by the storage time, which was confirmed by increased values of the acid value (AV and peroxide value (PV of the oil samples. Fresh seed oil had an AV of 0.49±0.01 mgKOH/g, while oils that were obtained from one-year old seeds had an AV of 1.95±0.02 mgKOH/g. Content of the primary oxidation products in the oil obtained by cold-pressing of the fresh seeds was 1.73±0.02 mmol/kg (measured as PV, and 2.22±0.07 mmol/kg in that from the seeds stored for 12 months. The anisidine value for the oil obtained from the seeds stored for 12 months was 0.86±0.04 (100A1% 350nm.[ Projekat Ministarstva nauke Republike Srbije, br. TR 31014

  15. 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

  16. 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,

  17. Impact of planting dates on a seed maggot, Neotephritis finalis (Diptera: Tephritidae), and sunflower bud moth (Lepidoptera: Tortricidae) damage in cultivated sunflower

    Science.gov (United States)

    Neotephritis finalis (Loew) (Diptera: Tephritidae), and sunflower bud moth, Suleima helianthana (Riley) (Lepidoptera: Tortricidae) are major head-infesting insect pests of cultivated sunflower (Helianthus annuus L.). Planting date was evaluated as a cultural pest management strategy for control of N...

  18. Aflatoxin levels in sunflower seeds and cakes collected from micro- and small-scale sunflower oil processors in Tanzania.

    Science.gov (United States)

    Mmongoyo, Juma A; Wu, Felicia; Linz, John E; Nair, Muraleedharan G; Mugula, Jovin K; Tempelman, Robert J; Strasburg, Gale M

    2017-01-01

    Aflatoxin, a mycotoxin found commonly in maize and peanuts worldwide, is associated with liver cancer, acute toxicosis, and growth impairment in humans and animals. In Tanzania, sunflower seeds are a source of snacks, cooking oil, and animal feed. These seeds are a potential source of aflatoxin contamination. However, reports on aflatoxin contamination in sunflower seeds and cakes are scarce. The objective of the current study was to determine total aflatoxin concentrations in sunflower seeds and cakes from small-scale oil processors across Tanzania. Samples of sunflower seeds (n = 90) and cakes (n = 92) were collected across two years, and analyzed for total aflatoxin concentrations using a direct competitive enzyme-linked immunosorbent assay (ELISA). For seed samples collected June-August 2014, the highest aflatoxin concentrations were from Dodoma (1.7-280.6 ng/g), Singida (1.4-261.8 ng/g), and Babati-Manyara (1.8-162.0 ng/g). The highest concentrations for cakes were from Mbeya (2.8-97.7 ng/g), Dodoma (1.9-88.2 ng/g), and Singida (2.0-34.3 ng/g). For seed samples collected August-October 2015, the highest concentrations were from Morogoro (2.8-662.7 ng/g), Singida (1.6-217.6 ng/g) and Mbeya (1.4-174.2 ng/g). The highest concentrations for cakes were from Morogoro (2.7-536.0 ng/g), Dodoma (1.4-598.4 ng/g) and Singida (3.2-52.8 ng/g). In summary, humans and animals are potentially at high risk of exposure to aflatoxins through sunflower seeds and cakes from micro-scale millers in Tanzania; and location influences risk.

  19. Oilfield water treatment by electrocoagulation-reverse osmosis for agricultural use: effects on germination and early growth characteristics of sunflower.

    Science.gov (United States)

    de Souza, Paulo S A; Cerqueira, Alexandre A; Rigo, Michelle M; de Paiva, Julieta L; Couto, Rafael S P; Merçon, Fábio; Perez, Daniel V; Marques, Monica R C

    2016-08-22

    This study aims to evaluate the effects of oilfield water (OW), treated by a hybrid process of electrocoagulation and reverse osmosis (EC-RO), on seed germination and early growth characteristics of sunflower (Heliantus annus L.). In the EC step, tests were conducted with 28.6 A m(-2) current density and 4 min. reaction time. In the RO step, the system was operated with 1 L min(-1) constant flow and 2 MPa, 2.5 MPa and 3 MPa feed pressures. In all feed pressures, RO polymeric membranes achieved very high removals of chemical oxygen demand (up to 89%) and oils and greases (100%) from EC-treated effluent. In best feed pressure (2.5 MPa), turbidity, total dissolved salts, electrical conductivity, salinity, toxic ions and sodium adsorption ratio values attained internationally recognized standards for irrigation water. Using EC-RO (feed pressure:2.5 MPa) treated OW, germinated sunflower seeds percentage (86 ± 6%), speed of germination (30 ± 2) and biomass production (49 ± 5 mg) were statistically similar to control (distilled water) results. Vigor index average values obtained using OW treated by EC-RO (3871)were higher than that obtained by OW water treated by EC (3300). The results of this study indicate that EC-RO seems to be a promising alternative for treatment of OW aiming sunflower crops irrigation, since the use of this treated effluent did not affect adversely seed germination and seedling development, and improved seedling vigor. Furthermore, OW treatment by EC-RO reduces sodium levels into acceptable standards values avoiding soil degradation.

  20. Phenotypic and genotypic variability of disc flower corolla length and nectar content in sunflower

    Directory of Open Access Journals (Sweden)

    Joksimović Jovan

    2003-01-01

    Full Text Available The nectar content and disc flower corolla length are the two most important parameters of attractiveness to pollinators in sunflower. The phenotypic and genotypic variability of these two traits was studied in four commercially important hybrids and their parental components in a trial with three fertilizer doses over two years. The results showed that, looking at individual genotypes, the variability of disc flower corolla length was affected the most by year (85.38-97.46%. As the study years were extremely different, the phenotypic variance of the hybrids and parental components was calculated for each year separately. In such conditions, looking at all of the crossing combinations, the largest contribution to phenotypic variance of the corolla length was that of genotype: 57.27-61.11% (NS-H-45 64.51-84.84% (Velja; 96.74-97.20% (NS-H-702 and 13.92-73.17% (NS-H-111. A similar situation was observed for the phenotypic variability of nectar content, where genotype also had the largest influence, namely 39.77-48.25% in NS-H-45; 39.06-42.51% in Velja; 31.97-72.36% in NS-H-702; and 62.13-94.96% in NS-H-111.

  1. Impact of combining planting date and chemical control to reduce larval densities of stem-infesting pests of sunflower in the central plains.

    Science.gov (United States)

    Charlet, Laurence D; Aiken, Robert M; Meyer, Ron F; Gebre-Amlak, Assefa

    2007-08-01

    The guild of stem-infesting insect pests of sunflower, Helianthus annuus L., within the central Plains is a concern to producers chiefly due to losses caused by plant lodging from the sunflower stem weevil, Cylindrocopturus adspersus (LeConte) (Coleoptera: Curculionidae), and Dectes texanus texanus LeConte (Coleoptera: Cerambycidae). The incidence of a root boring moth, Pelochrista womonana (Kearfott) (Lepidoptera: Tortricidae), also has increased. Experiments were conducted in three locations in Colorado and Kansas during 2001-2003 to investigate the potential of combining planting date and foliar and seed treatment insecticide applications to lower insect stalk densities of these three pests. The impact of these strategies on weevil larval parasitoids also was studied. Eight sunflower stem weevil larval parasitoid species were identified. All were Hymenoptera and included the following (relative composition in parentheses): Nealiolus curculionis (Fitch) (42.6%), Nealiolus collaris (Brues) (3.2%) (Braconidae), Quadrastichus ainsliei Gahan (4.2%) (Eulophidae), Eurytoma tylodermatis Ashmead (13.1%) (Eurytomidae), Neocatolaccus tylodermae (Ashmead) (33.7%), Chlorocytus sp. (1.6%), Pteromalus sp. (0.5%) (Pteromalidae), and Eupelmus sp. (1.0%) (Eupelmidae). The results from this 3-yr study revealed that chemical control was often reliable in protecting the sunflower crop from stem pests and was relatively insensitive to application timing. Although results in some cases were mixed, overall, delayed planting can be a reliable and effective management tool for growers in the central Plains to use in reducing stem-infesting pest densities in sunflower stalks. Chemical control and planting date were compatible with natural mortality contributed by C. adspersus larval parasitoids.

  2. Vegetable oil spills on salt marsh sediments; comparison between sunflower and linseed oils.

    Science.gov (United States)

    Pereira, M Glória; Mudge, Stephen M; Latchford, John

    2003-09-01

    The effects of a simulated spill of sunflower oil in salt marsh sediments were compared with an experiment with linseed oil. Sunflower and linseed oil penetrated the sediments at the same rates but different adsorption of the oils onto sediment particles resulted in the establishment of anaerobic conditions at shallower depths in sediments contaminated with linseed oil than with sunflower oil. The total lipid content of sunflower oil contaminated sediments remained almost stable for 6 months, whilst only 40% of linseed oil remained in the sediment after 2 months. Numbers of culturable heterotrophic bacteria and aerobic oil degrading bacteria in muddy sediment increased rapidly in response to the presence of the oils but bacterial numbers in sandy sediments increased more slowly for sunflower oil. Changes in fatty acid composition indicate similar degradation pathways for both oils but sunflower oil degraded more slowly than linseed oil and thus has the potential for longer lasting effects in marine environments.

  3. Genomic islands of divergence are not affected by geography of speciation in sunflowers.

    Science.gov (United States)

    Renaut, S; Grassa, C J; Yeaman, S; Moyers, B T; Lai, Z; Kane, N C; Bowers, J E; Burke, J M; Rieseberg, L H

    2013-01-01

    Genomic studies of speciation often report the presence of highly differentiated genomic regions interspersed within a milieu of weakly diverged loci. The formation of these speciation islands is generally attributed to reduced inter-population gene flow near loci under divergent selection, but few studies have critically evaluated this hypothesis. Here, we report on transcriptome scans among four recently diverged pairs of sunflower (Helianthus) species that vary in the geographical context of speciation. We find that genetic divergence is lower in sympatric and parapatric comparisons, consistent with a role for gene flow in eroding neutral differences. However, genomic islands of divergence are numerous and small in all comparisons, and contrary to expectations, island number and size are not significantly affected by levels of interspecific gene flow. Rather, island formation is strongly associated with reduced recombination rates. Overall, our results indicate that the functional architecture of genomes plays a larger role in shaping genomic divergence than does the geography of speciation.

  4. Arsenic-contaminated soils. Phytotoxicity studies with sunflower and sorghum

    Energy Technology Data Exchange (ETDEWEB)

    Lyubun, Y.V.; Kosterin, P.V.; Zakharova, E.A.; Fedorov, E.E. [Inst. of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov (Russian Federation); Shcherbakov, A.A. [Saratov Military Inst. of Radiological, Chemical and Biological Defence, Saratov (Russian Federation)

    2002-07-01

    Background, Aim and Scope. Environmental pollution caused by arsenic (As) is a major ecological problem. There has been intense worldwide effort to find As-hyperaccumulating plants that can be used in phytoremediation - the green-plant-assisted removal of chemical pollutants from soils. For phytoremediation, it is natural to prefer cultivated rather than wild plants, because their agriculture is well known. This study was conducted to evaluate the tolerance of common sunflower (Helianthus annuus L.) and sugar sorghum (Sorghum saccharatum Pers.) for soil-As contents of 10-100 mg As kg{sup -1} soil, with sodium arsenite as a model contaminant. Methods. Plants were grown in a growth chamber for 30 days. Microfield experiments were conducted on experimental plots. To study the phytoremediation effect of the auxins indole-3-acetic acid (IAA) and 2,4-dichlorophenoxyacetic acid (2,4-D), we treated 1- and 3-day-old plant seedlings with water solutions of the auxins (concentrations of 10{sup -5}, 10{sup -7}, and 10{sup -9} g l{sup -1}). The soil and plant-biomass samples were analyzed for total As by using the color reaction of ammonium molybdate with As. Results and Discussion. Phytotoxicity studies showed that 100 mg as kg{sup -1} soil poisoned sunflower and sorghum growth by 50%. There was a linear correlation between soil-As content and As accumulation in the plants. Laboratory experiments showed that the soil-As content was reduced two- to threefold after sunflower had been grown with 10-100 mg As kg{sup -1} soil for 30 days. Treatment of sunflower and sorghum seedlings with IAA and 2,4-D at a concentration of 10{sup -5} g l{sup -1} in microfield experiments enhanced the phytoremediation two- to fivefold as compared with untreated control plants. The best results were obtained with 3-day-old seedlings. Conclusion, Recommendation and Outlook. (a) Sunflower and sorghum are good candidates to remediate As-polluted soils. (b) Phytoremediation can be improved with IAA or 2

  5. 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...

  6. Investigation of Correlation between Traits and Path Analysis of Confectionary Sunflower Genotypes

    OpenAIRE

    SINCIK, Mehmet; Abdurrahim Tanju GOKSOY

    2014-01-01

    Abstract. This study examined the relationships between various traits associated with seed and crude protein yields of confectionary sunflower as well as the direct and indirect effects of these traits on crude protein yield. Eight open-pollinated confectionary sunflower populations and two open-pollinated confectionary sunflower cultivars used as control varieties were evaluated during two growing seasons (2009 and 2010). Certain agronomical and technological traits such as plant height, he...

  7. Quantifying temporal isolation: a modelling approach assessing the effect of flowering time differences on crop-to-weed pollen flow in sunflower.

    Science.gov (United States)

    Roumet, Marie; Cayre, Adeline; Latreille, Muriel; Muller, Marie-Hélène

    2015-01-01

    Flowering time divergence can be a crucial component of reproductive isolation between sympatric populations, but few studies have quantified its actual contribution to the reduction of gene flow. In this study, we aimed at estimating pollen-mediated gene flow between cultivated sunflower and a weedy conspecific sunflower population growing in the same field and at quantifying, how it is affected by the weeds' flowering time. For that purpose, we extended an existing mating model by including a temporal distance (i.e. flowering time difference between potential parents) effect on mating probabilities. Using phenological and genotypic data gathered on the crop and on a sample of the weedy population and its offspring, we estimated an average hybridization rate of approximately 10%. This rate varied strongly from 30% on average for weeds flowering at the crop flowering peak to 0% when the crop finished flowering and was affected by the local density of weeds. Our result also suggested the occurrence of other factors limiting crop-to-weed gene flow. This level of gene flow and its dependence on flowering time might influence the evolutionary fate of weedy sunflower populations sympatric to their crop relative.

  8. 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.

  9. 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

  10. The Effectof Temperature on the Dynmaic Viscosity of Acetone Sunflower-Seed Oil Mixtures

    OpenAIRE

    TOPALLAR, Hüseyin; BAYRAK, Yüksel

    1998-01-01

    The effect of acetone on the dynamic viscosity of sunflower-seed oil was studied under a dynamic heating regime at temeparuters ranging from 25oC to 50oC at 5oC intervals. Acetone dramatically reduced the viscosity of sunflower-seed oil. The reduction of viscosity was far less with further addition of acetone. A linear relationship was found between the density of sunflower-seed oil and temperature. The influence of a solvent on the density of the sunflower-seed oil/acetone solution can be ac...

  11. Sunflower-based Feedstocks in Nonfood Applications: Perspectives from Olefin Metathesis

    Science.gov (United States)

    Marvey, Bassie B.

    2008-01-01

    Sunflower (Helianthus annuus L.) oil remains under-utilised albeit one of the major seed oils produced world-wide. Moreover, the high oleic sunflower varieties make the oil attractive for applications requiring high temperature processes and those targeting the C=C double bond functionality. Herein an overview of the recent developments in olefin metathesis of sunflower-based feedstocks is presented. The improved performance of olefin metathesis catalysts leading to high turnover numbers, high selectivity and catalyst recyclability, opens new opportunities for tailoring sunflower-based feedstocks into products required for possible new niche market applications. Promising results in biofuel, biopolymers, fragrances and fine chemicals applications have been reported. PMID:19325810

  12. Research of Broomrape Resistance in Sunflower Resources%向日葵资源列当抗性研究

    Institute of Scientific and Technical Information of China (English)

    王文军

    2013-01-01

    Based on the identification test of two years pot inoculation,this thesis studied the orobanche weed resistance of sunflower resources,researched distribution law of anti-source.The results showed that forty-one sunflower resources resistance were analysed,including twenty-five immune materials,two high resistance materials,seven resistant materials,six susceptible materials,and one high sensitive material.The resistance sources widely existed in outside source material,oil materials,hybrids and were not found in the local resources.%通过2年盆栽接种鉴定试验,研究向日葵资源对列当的抗性,并对资源抗性规律进行分析.结果表明:对41份向日葵资源进行抗性分析,其中免疫材料25份,高抗材料2份,抗性材料7份,易感材料6份,高感材料1份;抗源在外源材料、油用材料、杂交种中广泛存在,本地资源中没有免疫材料.

  13. Polyadenylation accelerates the degradation of the mitochondrial mRNA associated with cytoplasmic male sterility in sunflower.

    Science.gov (United States)

    Gagliardi, D; Leaver, C J

    1999-07-01

    In sunflower, PET1-cytoplasmic male sterility is correlated with the presence of a novel mitochondrial gene (orf522) located 3' to the atpA gene. The dicistronic atpA-orf522 transcripts are preferentially destabilized in male florets of 'restored to fertility' plants as compared with sterile plants. In this report, we show that atpA-orf522 transcripts may be polyadenylated in vivo at their 3' termini and that a tissue-specific increase in the level of polyadenylated atpA-orf522 transcripts correlates with the tissue-specific instability of atpA-orf522 mRNAs in male florets of the restored hybrid plants. In addition, we have identified two distinct ribonuclease activities in sunflower mitochondria, one of which preferentially degrades polyadenylated as compared with non-polyadenylated RNA substrates corresponding to the 3' UTR of atpA-orf522 transcripts. These in vivo and in vitro results show that polyadenylation is involved in the degradation pathway of the mitochondrial atpA-orf522 transcripts and that polyadenylation can be developmentally regulated by a nuclear gene(s) upon restoration of fertility.

  14. Efficacy of honeybees (Apis mellifera on the production of sunflower (Helianthus annus L. seeds in the Sudan

    Directory of Open Access Journals (Sweden)

    Osman Abd Elmhmoud Altayeb

    2015-04-01

    Full Text Available Study was conducted to test the efficacy of the honeybees in the production of sunflower seeds. This experiment was conducted in Complete Randomized Block Design in the cropping season of 2011- 2012 at Sinnar region, Sudan. Three different patterns of pollination i.e. pollination with honey bee (H, open pollination (O and control without pollination (C were tested for the seed set in sun flower. Each treatments contains twenty (20 plants. Results of study revealed significant differences among the tested pollination pattern. Among these highest seed set ratios (80% and 79% were obtained in the open (O and honey bee (H pollination system. While only 45.2% seed set was reported in the control (C where plants kept in closed system and away from insect pollination. Furthermore, the mean seeds weights per head (27.65g and 26.88g were also reported higher in open and honey bee pollinated system and it was 162.3% and 155% higher than the control respectively. Similar types of trends was reported in the weight parameters of hundred seeds, the superiority was shown by open and honey bee pollination. This weight was 52% and 45% higher than the control treatment (C respectively. Therefore, the results of the study revealed that use of honeybees as pollinator for sunflower can contribute in hybrid seed production in better manner.

  15. Volumetric properties of sunflower methyl ester oil at high pressure.

    Science.gov (United States)

    Aparicio, Cristina; Guignon, Bérengère; Rodríguez-Antón, Luis M; Sanz, Pedro D

    2007-09-01

    Biodiesel is an alternative to diesel oil (DO), because it is a fuel obtained from renewable resources that has lower emissions than DO. Biomass production should promote agricultural activity to obtain fuels for the transport sector. The study of the behavior of biodiesel at varying pressure and temperature is very interesting because diesel engines are mechanical systems that work with fuels submitted to high pressure. The specific volume, isothermal compressibility, and cubic expansion coefficients of refined sunflower methyl ester oil (SMEO) and unrefined sunflower methyl ester oil (URSMEO) were obtained and compared with those of DO from 0.1 to 350 MPa and 288.15 to 328.15 K. This work shows that oil refinement did not significantly modify any of the properties studied of the final biodiesel. Compared with DO, both SMEOs were about 6% denser, whereas isothermal compressibility and cubic expansion coefficients were bigger or smaller for DO depending on pressure and temperature.

  16. Evaluation and characterization of sunflower germplasm accessions for quantitative characters

    Directory of Open Access Journals (Sweden)

    Vikas Kulkarni, I.Shankegoud and M.R. Govindappa

    2015-03-01

    Full Text Available Sunflower germplasm accessions (143 were evaluated for yield and yield contributing characters to study the extentof variation for different quantitative traits. The germplasm accessions were also characterized on qualitative traits. Highest phenotypic and genotypic coefficients of variation were recorded for seed yield per plant (53.4 % and 46.9% respectively followed by head diameter, test weight, plant height,volume weight and oil content. High heritability was noticed for all the traits studied. High heritability coupled with high genetic advance over mean has been recorded for seed yield per plant (77 and 65.1 followed by head diameter, test weight and plant height. It was noticed that sunflower germplasm accessions exhibited wide range of variability for all the morphological characters studied like leaf shape, leaf color, leaf serrations, leaf hairiness, stem hairiness, indicator leaf, petiole anthocyanin, branching, leaf angle, petiole length, stem pigmentation and pollen color.

  17. Plant response to sunflower seeds to osmotic conditioning

    Directory of Open Access Journals (Sweden)

    Camila Santos Barros de Morais

    2014-10-01

    Full Text Available The aim of this study was to evaluate the effect of seeds osmotic conditioning in seedlings emergence and plants performance of sunflower. Three lots of seeds sunflower (Catissol, was submited to osmotic conditioning with polyethylene glycol solution, –2,0 MPa in aerated system, under 15 ºC for 8 hour and then was evaluated for germination tests and vigour. Under filed conditions was conducted emergency evaluations of seedling, plants development as well as the productivity and seeds quality, and the accumulation of nutrients in the seeds. The osmotic conditioning improve the survival of seedling, the dry matter mass to aerial part of plants from 60 days after sowing and oil content, in lots with low seeds physiological quality. The osmotic conditioning not increase the seeds yield but promotes the vigour of seeds produced, regardless of the lot used for sowing seeds.

  18. 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...

  19. 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...

  20. Breeding sunflower (Helianthus annuus L.) for drought tolerance

    OpenAIRE

    Saeed Ra