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Sample records for hexaploid wheat population

  1. Application of Population Sequencing (POPSEQ) for Ordering and Imputing Genotyping-by-Sequencing Markers in Hexaploid Wheat

    PubMed Central

    Edae, Erena A.; Bowden, Robert L.; Poland, Jesse

    2015-01-01

    The advancement of next-generation sequencing technologies in conjunction with new bioinformatics tools enabled fine-tuning of sequence-based, high-resolution mapping strategies for complex genomes. Although genotyping-by-sequencing (GBS) provides a large number of markers, its application for association mapping and genomics-assisted breeding is limited by a large proportion of missing data per marker. For species with a reference genomic sequence, markers can be ordered on the physical map. However, in the absence of reference marker order, the use and imputation of GBS markers is challenging. Here, we demonstrate how the population sequencing (POPSEQ) approach can be used to provide marker context for GBS in wheat. The utility of a POPSEQ-based genetic map as a reference map to create genetically ordered markers on a chromosome for hexaploid wheat was validated by constructing an independent de novo linkage map of GBS markers from a Synthetic W7984 × Opata M85 recombinant inbred line (SynOpRIL) population. The results indicated that there is strong agreement between the independent de novo linkage map and the POPSEQ mapping approach in mapping and ordering GBS markers for hexaploid wheat. After ordering, a large number of GBS markers were imputed, thus providing a high-quality reference map that can be used for QTL mapping for different traits. The POPSEQ-based reference map and whole-genome sequence assemblies are valuable resources that can be used to order GBS markers and enable the application of highly accurate imputation methods to leverage the application GBS markers in wheat. PMID:26530417

  2. Genetic Diversity and Population Structure Analysis of European Hexaploid Bread Wheat (Triticum aestivum L.) Varieties

    PubMed Central

    Nielsen, Nanna Hellum; Backes, Gunter; Stougaard, Jens; Andersen, Stig Uggerhj; Jahoor, Ahmed

    2014-01-01

    Progress in plant breeding is facilitated by accurate information about genetic structure and diversity. Here, Diversity Array Technology (DArT) was used to characterize a population of 94 bread wheat (Triticum aestivum L.) varieties of mainly European origin. In total, 1,849 of 7,000 tested markers were polymorphic and could be used for population structure analysis. Two major subgroups of wheat varieties, GrI and GrII, were identified using the program STRUCTURE, and confirmed by principal component analysis (PCA). These subgroups were largely separated according to origin; GrI comprised varieties from Southern and Eastern Europe, whereas GrII contained mostly modern varieties from Western and Northern Europe. A large proportion of the markers contributing most to the genetic separation of the subgroups were located on chromosome 2D near the Reduced height 8 (Rht8) locus, and PCR-based genotyping suggested that breeding for the Rht8 allele had a major impact on subgroup separation. Consistently, analysis of linkage disequilibrium (LD) suggested that different selective pressures had acted on chromosome 2D in the two subgroups. Our data provides an overview of the allele composition of bread wheat varieties anchored to DArT markers, which will facilitate targeted combination of alleles following DArT-based QTL studies. In addition, the genetic diversity and distance data combined with specific Rht8 genotypes can now be used by breeders to guide selection of crossing parents. PMID:24718292

  3. Identification of quantitative trait loci controlling grain size and shape in the D genome of synthetic hexaploid wheat lines

    PubMed Central

    Okamoto, Yuki; Nguyen, Anh T.; Yoshioka, Motohiro; Iehisa, Julio C.M.; Takumi, Shigeo

    2013-01-01

    Synthetic hexaploid wheat is an effective genetic resource for transferring agronomically important genes from Aegilops tauschii to common wheat. Wide variation in grain size and shape, one of the main targets for wheat breeding, has been observed among Ae. tauschii accessions. To identify the quantitative trait loci (QTLs) responsible for grain size and shape variation in the wheat D genome under a hexaploid genetic background, six parameters related to grain size and shape were measured using SmartGrain digital image software and QTL analysis was conducted using four F2 mapping populations of wheat synthetic hexaploids. In total, 18 QTLs for the six parameters were found on five of the seven D-genome chromosomes. The identified QTLs significantly contributed to the variation in grain size and shape among the synthetic wheat lines, implying that the D-genome QTLs might be at least partly functional in hexaploid wheat. Thus, synthetic wheat lines with diverse D genomes from Ae. tauschii are useful resources for the identification of agronomically important loci that function in hexaploid wheat. PMID:24399915

  4. Virus-Induced Gene Silencing in Hexaploid Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Functional genomics analysis in hexaploid wheat is greatly impeded by the genetic redundancy of polyploidy and the difficulties in generating large numbers of transgenic plants required in insertional mutagenesis strategies. Virus-induced gene silencing (VIGS), however, is a strategy for creating g...

  5. Comparison of Genomic Selection Models to Predict Flowering Time and Spike Grain Number in Two Hexaploid Wheat Doubled Haploid Populations

    PubMed Central

    Thavamanikumar, Saravanan; Dolferus, Rudy; Thumma, Bala R.

    2015-01-01

    Genomic selection (GS) is becoming an important selection tool in crop breeding. In this study, we compared the ability of different GS models to predict time to young microspore (TYM), a flowering time-related trait, spike grain number under control conditions (SGNC) and spike grain number under osmotic stress conditions (SGNO) in two wheat biparental doubled haploid populations with unrelated parents. Prediction accuracies were compared using BayesB, Bayesian least absolute shrinkage and selection operator (Bayesian LASSO / BL), ridge regression best linear unbiased prediction (RR-BLUP), partial least square regression (PLS), and sparse partial least square regression (SPLS) models. Prediction accuracy was tested with 10-fold cross-validation within a population and with independent validation in which marker effects from one population were used to predict traits in the other population. High prediction accuracies were obtained for TYM (0.51–0.84), whereas moderate to low accuracies were observed for SGNC (0.10–0.42) and SGNO (0.27–0.46) using cross-validation. Prediction accuracies based on independent validation are generally lower than those based on cross-validation. BayesB and SPLS outperformed all other models in predicting TYM with both cross-validation and independent validation. Although the accuracies of all models are similar in predicting SGNC and SGNO with cross-validation, BayesB and SPLS had the highest accuracy in predicting SGNC with independent validation. In independent validation, accuracies of all the models increased by using only the QTL-linked markers. Results from this study indicate that BayesB and SPLS capture the linkage disequilibrium between markers and traits effectively leading to higher accuracies. Excluding markers from QTL studies reduces prediction accuracies. PMID:26206349

  6. Comparison of Genomic Selection Models to Predict Flowering Time and Spike Grain Number in Two Hexaploid Wheat Doubled Haploid Populations.

    PubMed

    Thavamanikumar, Saravanan; Dolferus, Rudy; Thumma, Bala R

    2015-10-01

    Genomic selection (GS) is becoming an important selection tool in crop breeding. In this study, we compared the ability of different GS models to predict time to young microspore (TYM), a flowering time-related trait, spike grain number under control conditions (SGNC) and spike grain number under osmotic stress conditions (SGNO) in two wheat biparental doubled haploid populations with unrelated parents. Prediction accuracies were compared using BayesB, Bayesian least absolute shrinkage and selection operator (Bayesian LASSO / BL), ridge regression best linear unbiased prediction (RR-BLUP), partial least square regression (PLS), and sparse partial least square regression (SPLS) models. Prediction accuracy was tested with 10-fold cross-validation within a population and with independent validation in which marker effects from one population were used to predict traits in the other population. High prediction accuracies were obtained for TYM (0.51-0.84), whereas moderate to low accuracies were observed for SGNC (0.10-0.42) and SGNO (0.27-0.46) using cross-validation. Prediction accuracies based on independent validation are generally lower than those based on cross-validation. BayesB and SPLS outperformed all other models in predicting TYM with both cross-validation and independent validation. Although the accuracies of all models are similar in predicting SGNC and SGNO with cross-validation, BayesB and SPLS had the highest accuracy in predicting SGNC with independent validation. In independent validation, accuracies of all the models increased by using only the QTL-linked markers. Results from this study indicate that BayesB and SPLS capture the linkage disequilibrium between markers and traits effectively leading to higher accuracies. Excluding markers from QTL studies reduces prediction accuracies. PMID:26206349

  7. Evolution of physiological responses to salt stress in hexaploid wheat

    PubMed Central

    Yang, Chunwu; Zhao, Long; Zhang, Huakun; Yang, Zongze; Wang, Huan; Wen, Shanshan; Zhang, Chunyu; Rustgi, Sachin; von Wettstein, Diter; Liu, Bao

    2014-01-01

    Hexaploid bread wheat (Triticum aestivum L., genome BBAADD) is generally more salt tolerant than its tetraploid wheat progenitor (Triticum turgidum L.). However, little is known about the physiological basis of this trait or about the relative contributions of allohexaploidization and subsequent evolutionary genetic changes on the trait development. Here, we compared the salt tolerance of a synthetic allohexaploid wheat (neo-6x) with its tetraploid (T. turgidum; BBAA) and diploid (Aegilops tauschii; DD) parents, as well as a natural hexaploid bread wheat (nat-6x). We studied 92 morphophysiological traits and analyzed homeologous gene expression of a major salt-tolerance gene High-Affinity K+ Transporter 1;5 (HKT1;5). We observed that under salt stress, neo-6x exhibited higher fitness than both of its parental genotypes due to inheritance of favorable traits like higher germination rate from the 4x parent and the stronger root Na+ retention capacity from the 2x parent. Moreover, expression of the D-subgenome HKT1;5 homeolog, which is responsible for Na+ removal from the xylem vessels, showed an immediate transcriptional reprogramming following allohexaploidization, i.e., from constitutive high basal expression in Ae. tauschii (2x) to salt-induced expression in neo-6x. This phenomenon was also witnessed in the nat-6x. An integrated analysis of 92 traits showed that, under salt-stress conditions, neo-6x resembled more closely the 2x than the 4x parent, suggesting that the salt stress induces enhanced expressivity of the D-subgenome homeologs in the synthetic hexaploid wheat. Collectively, the results suggest that condition-dependent functionalization of the subgenomes might have contributed to the wide-ranging adaptability of natural hexaploid wheat. PMID:25074914

  8. Evaluation and haplotype analysis of elite synthetic hexaploid wheat lines for resistance to Hessian fly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Synthetic hexaploid wheat (SHW), derived from tetraploid wheat ' Aegilops tauschii hybrid, is an excellent source of resistance genes for various diseases and insects in wheat. The objectives of this study were to evaluate the elite SHW lines developed at the International Maize and Wheat Improvemen...

  9. Synthetic hexaploids: Harnessing species of the primary gene pool for wheat improvement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incorporation of genetic diversity into elite wheat cultivars has long been recognized as a means of improving wheat productivity and securing the global wheat supply. Synthetic hexaploid wheat (SHW) recreated from its two progenitor species, the tetraploid, Triticum turgidum and its diploid wild r...

  10. New broad-spectrum resistance to septoria tritici blotch derived from synthetic hexaploid wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Septoria tritici blotch (STB), caused by the ascomycete Mycosphaerella graminicola, is one of the most devastating foliar diseases of wheat. We screened five synthetic hexaploid wheats (SHs), 13 wheat varieties that represent the differential set of cultivars and two susceptible checks with a global...

  11. Registration of hard kernel puroindoline allele nearisogenic line hexaploid wheat genetic stocks.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seven puroindoline allele near-isogenic line (NIL) hexaploid wheat (Triticum aestivum L.) genetic stocks (GS-xxxx – GS-xxxx; PI 644080 – PI 644086) were developed by Dr. Craig F. Morris at the USDA-ARS Western Wheat Quality Laboratory, Pullman, Washington. As they incorporate the first seven known ...

  12. Genetic diversity among synthetic hexaploid wheat accessions with resistance to several fungal diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Synthetic hexaploid wheat (SHW) is known to be an excellent vehicle for transferring large genetic variations especially the many useful traits present in the D genome of Aegilops tauschii Coss (2n=2x=14, DD) for improvement of cultivated wheat (Triticum aestivum L., 2n=6x=42, AABBDD). The objectiv...

  13. NOTICE OF RELEASE OF HARD KERNEL PUROINDOLINE ALLELE NEAR-ISOGENIC LINE HEXAPLOID WHEAT GENETIC STOCKS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Agricultural Research Service, U.S. Department of Agriculture announces the release of seven hard kernel puroindoline allele near-isogenic line (NIL) hexaploid wheat (Triticum aestivum L.) genetic stocks (PI xxxxxx – PI xxxxxx) developed by Dr. Craig F. Morris at the USDA-ARS Western Wheat Quali...

  14. Simultaneous editing of three homoeoalleles in hexaploid bread wheat confers heritable resistance to powdery mildew.

    PubMed

    Wang, Yanpeng; Cheng, Xi; Shan, Qiwei; Zhang, Yi; Liu, Jinxing; Gao, Caixia; Qiu, Jin-Long

    2014-09-01

    Sequence-specific nucleases have been applied to engineer targeted modifications in polyploid genomes, but simultaneous modification of multiple homoeoalleles has not been reported. Here we use transcription activator-like effector nuclease (TALEN) and clustered, regularly interspaced, short palindromic repeats (CRISPR)-Cas9 (refs. 4,5) technologies in hexaploid bread wheat to introduce targeted mutations in the three homoeoalleles that encode MILDEW-RESISTANCE LOCUS (MLO) proteins. Genetic redundancy has prevented evaluation of whether mutation of all three MLO alleles in bread wheat might confer resistance to powdery mildew, a trait not found in natural populations. We show that TALEN-induced mutation of all three TaMLO homoeologs in the same plant confers heritable broad-spectrum resistance to powdery mildew. We further use CRISPR-Cas9 technology to generate transgenic wheat plants that carry mutations in the TaMLO-A1 allele. We also demonstrate the feasibility of engineering targeted DNA insertion in bread wheat through nonhomologous end joining of the double-strand breaks caused by TALENs. Our findings provide a methodological framework to improve polyploid crops. PMID:25038773

  15. Genetic association of OPR genes with resistance to Hessian fly in hexaploid wheat

    PubMed Central

    2013-01-01

    Background Hessian fly (Mayetiola destructor) is one of the most destructive pests of wheat. The genes encoding 12-oxo-phytodienoic acid reductase (OPR) and lipoxygenase (LOX) play critical roles in insect resistance pathways in higher plants, but little is known about genes controlling resistance to Hessian fly in wheat. Results In this study, 154 F6:8 recombinant inbred lines (RILs) generated from a cross between two cultivars, ‘Jagger’ and ‘2174’ of hexaploid wheat (2n = 6 × =42; AABBDD), were used to map genes associated with resistance to Hessian fly. Two QTLs were identified. The first one was a major QTL on chromosome 1A (QHf.osu-1A), which explained 70% of the total phenotypic variation. The resistant allele at this locus in cultivar 2174 could be orthologous to one or more of the previously mapped resistance genes (H9, H10, H11, H16, and H17) in tetraploid wheat. The second QTL was a minor QTL on chromosome 2A (QHf.osu-2A), which accounted for 18% of the total phenotypic variation. The resistant allele at this locus in 2174 is collinear to an Yr17-containing-fragment translocated from chromosome 2N of Triticum ventricosum (2n = 4 × =28; DDNN) in Jagger. Genetic mapping results showed that two OPR genes, TaOPR1-A and TaOPR2-A, were tightly associated with QHf.osu-1A and QHf.osu-2A, respectively. Another OPR gene and three LOX genes were mapped but not associated with Hessian fly resistance in the segregating population. Conclusions This study has located two major QTLs/genes in bread wheat that can be directly used in wheat breeding programs and has also provided insights for the genetic association and disassociation of Hessian fly resistance with OPR and LOX genes in wheat. PMID:23724909

  16. Construction and characterization of a bacterial artificial chromosome library for hexaploid wheat line 92R137

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For map-based cloning of genes conferring important traits in the hexaploid wheat line 92R137, a bacterial artificial chromosome (BAC) library, including two sub libraries, was constructed using the genomic DNA of 92R137 digested with restriction enzymes HindIII and BamHI. The BAC library was compos...

  17. EVALUATION OF 10 CHEMICALS FOR ANEUPLOIDY INDUCTION IN THE HEXAPLOID WHEAT ASSAY

    EPA Science Inventory

    This study was a part of an international project sponsored by the Commission of the European Communities to evaluate the utility of the hexaploid wheat assay (Redei and Sandhu, 1988) to detect chemically induced aneuploidy. en known or suspect spindle poisons; i.e., colchicine (...

  18. Spontaneous and Divergent Hexaploid Triticales Derived from Common Wheat Rye by Complete Elimination of D-Genome Chromosomes

    PubMed Central

    Wang, Changyou; Ji, Wanquan

    2015-01-01

    Background Hexaploid triticale could be either synthesized by crossing tetraploid wheat with rye, or developed by crossing hexaploid wheat with a hexaploid triticale or an octoploid triticale. Methodology/Principal Findings Here two hexaploid triticales with great morphologic divergence derived from common wheat cultivar M8003 (Triticum aestivum L.) Austrian rye (Secale cereale L.) were reported, exhibiting high resistance for powdery mildew and stripe rust and potential for wheat improvement. Sequential fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH) karyotyping revealed that D-genome chromosomes were completely eliminated and the whole A-genome, B-genome and R-genome chromosomes were retained in both lines. Furthermore, plentiful alterations of wheat chromosomes including 5A and 7B were detected in both triticales and additionally altered 5B, 7A chromosome and restructured chromosome 2A was assayed in N9116H and N9116M, respectively, even after selfing for several decades. Besides, meiotic asynchrony was displayed and a variety of storage protein variations were assayed, especially in the HMW/LMW-GS region and secalins region in both triticales. Conclusion This study confirms that whole D-genome chromosomes could be preferentially eliminated in the hybrid of common wheat rye, genome shock was accompanying the allopolyploidization of nascent triticales, and great morphologic divergence might result from the genetic variations. Moreover, new hexaploid triticale lines contributing potential resistance resources for wheat improvement were produced. PMID:25781330

  19. Analysis of Breeding Systems, Ploidy, and the Role of Hexaploids in Three Hypericum perforatum L. Populations

    PubMed Central

    Qu, Luping; Widrlechner, Mark P.; Rigby, Shawn M.

    2010-01-01

    Hexaploid seeds are produced by predominantly tetraploid populations of Hypericum perforatum, but the fate of hexaploid seedlings and their reproductive behavior have not been closely examined. We used flow cytometry to analyze single seeds and individual plant samples of three accessions of H. perforatum to determine ploidy levels and reproductive pathways. Seed samples of all three accessions were facultative apomicts, with tetraploid cytotype predominant (8591%) and a lower frequency of hexaploids (914%), with diploids (5%) detected in only one population. Seedling populations consisted of tetraploids (8797%) and hexaploids (313%). Hexaploid embryos are most likely generated by a 2n gamete of the tetraploid and fertilized by a normal, reduced tetraploid male gamete. These hexaploids are expected to produce unbalanced gametes because they possess chromosome complements that include two triploid sets originally derived from two different species. The observation that some tetraploid seeds had endosperm with high cellular DNA content indicates that some unbalanced male gametes produced by hexaploids were evidently viable and could effect fertilization. Whether this mechanism is also true for egg cells or whether the hexaploids are capable of producing unreduced embryo sacs is uncertain. Because of severe reproductive difficulties, hexaploid seedlings may play a very minor role in gene flow and the further evolution of H. perforatum. The likelihood that hexaploids will evolve to types with an increased frequency of bivalent paring in meiosis is relatively low. However, hexaploids may include novel chemotypes, which could be vegetatively propagated if valuable, medicinal types can be identified among them. PMID:20448805

  20. Analysis of Breeding Systems, Ploidy, and the Role of Hexaploids in Three Hypericum perforatum L. Populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hexaploid seeds are produced by predominantly tetraploid populations of Hypericum perforatum, but the fate of hexaploid seedlings and their reproductive behavior have not been closely examined. We used flow cytometry to analyze single seeds and individual plant samples of three accessions of H. per...

  1. Synthetic hexaploids derived from under-exploited tetraploids as a new resource for disease resistance in wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Synthetic hexaploid wheat (SHW) (2n = 6x = 42, genome AABBDD), which is developed from the hybridization between tetraploid wheat (Triticum turgidum L., 2n = 4x = 28, genome AABB) and Aegilops tauschii Coss. (2n = 2x = 14, genome DD), is a useful bridging germplasm for the introgression of desirable...

  2. Structural and molecular basis of starch viscosity in hexaploid wheat.

    PubMed

    Ral, J-P; Cavanagh, C R; Larroque, O; Regina, A; Morell, M K

    2008-06-11

    Wheat starch is considered to have a low paste viscosity relative to other starches. Consequently, wheat starch is not preferred for many applications as compared to other high paste viscosity starches. Increasing the viscosity of wheat starch is expected to increase the functionality of a range of wheat flour-based products in which the texture is an important aspect of consumer acceptance (e.g., pasta, and instant and yellow alkaline noodles). To understand the molecular basis of starch viscosity, we have undertaken a comprehensive structural and rheological analysis of starches from a genetically diverse set of wheat genotypes, which revealed significant variation in starch traits including starch granule protein content, starch-associated lipid content and composition, phosphate content, and the structures of the amylose and amylopectin fractions. Statistical analysis highlighted the association between amylopectin chains of 18-25 glucose residues and starch pasting properties. Principal component analysis also identified an association between monoesterified phosphate and starch pasting properties in wheat despite the low starch-phosphate level in wheat as compared to tuber starches. We also found a strong negative correlation between the phosphate ester content and the starch content in flour. Previously observed associations between internal starch granule fatty acids and the swelling peak time and pasting temperature have been confirmed. This study has highlighted a range of parameters associated with increased starch viscosity that could be used in prebreeding/breeding programs to modify wheat starch pasting properties. PMID:18459791

  3. Genome interplay in the grain transcriptome of hexaploid bread wheat.

    PubMed

    Pfeifer, Matthias; Kugler, Karl G; Sandve, Simen R; Zhan, Bujie; Rudi, Heidi; Hvidsten, Torgeir R; Mayer, Klaus F X; Olsen, Odd-Arne

    2014-07-18

    Allohexaploid bread wheat (Triticum aestivum L.) provides approximately 20% of calories consumed by humans. Lack of genome sequence for the three homeologous and highly similar bread wheat genomes (A, B, and D) has impeded expression analysis of the grain transcriptome. We used previously unknown genome information to analyze the cell type-specific expression of homeologous genes in the developing wheat grain and identified distinct co-expression clusters reflecting the spatiotemporal progression during endosperm development. We observed no global but cell type- and stage-dependent genome dominance, organization of the wheat genome into transcriptionally active chromosomal regions, and asymmetric expression in gene families related to baking quality. Our findings give insight into the transcriptional dynamics and genome interplay among individual grain cell types in a polyploid cereal genome. PMID:25035498

  4. Genome-wide comparative diversity uncovers multiple targets of selection for improvement in hexaploid wheat landraces and cultivars

    PubMed Central

    Cavanagh, Colin R.; Chao, Shiaoman; Wang, Shichen; Huang, Bevan Emma; Stephen, Stuart; Kiani, Seifollah; Forrest, Kerrie; Saintenac, Cyrille; Brown-Guedira, Gina L.; Akhunova, Alina; See, Deven; Bai, Guihua; Pumphrey, Michael; Tomar, Luxmi; Wong, Debbie; Kong, Stephan; Reynolds, Matthew; da Silva, Marta Lopez; Bockelman, Harold; Talbert, Luther; Anderson, James A.; Dreisigacker, Susanne; Baenziger, Stephen; Carter, Arron; Korzun, Viktor; Morrell, Peter Laurent; Dubcovsky, Jorge; Morell, Matthew K.; Sorrells, Mark E.; Hayden, Matthew J.; Akhunov, Eduard

    2013-01-01

    Domesticated crops experience strong human-mediated selection aimed at developing high-yielding varieties adapted to local conditions. To detect regions of the wheat genome subject to selection during improvement, we developed a high-throughput array to interrogate 9,000 gene-associated single-nucleotide polymorphisms (SNP) in a worldwide sample of 2,994 accessions of hexaploid wheat including landraces and modern cultivars. Using a SNP-based diversity map we characterized the impact of crop improvement on genomic and geographic patterns of genetic diversity. We found evidence of a small population bottleneck and extensive use of ancestral variation often traceable to founders of cultivars from diverse geographic regions. Analyzing genetic differentiation among populations and the extent of haplotype sharing, we identified allelic variants subjected to selection during improvement. Selective sweeps were found around genes involved in the regulation of flowering time and phenology. An introgression of a wild relative-derived gene conferring resistance to a fungal pathogen was detected by haplotype-based analysis. Comparing selective sweeps identified in different populations, we show that selection likely acts on distinct targets or multiple functionally equivalent alleles in different portions of the geographic range of wheat. The majority of the selected alleles were present at low frequency in local populations, suggesting either weak selection pressure or temporal variation in the targets of directional selection during breeding probably associated with changing agricultural practices or environmental conditions. The developed SNP chip and map of genetic variation provide a resource for advancing wheat breeding and supporting future population genomic and genome-wide association studies in wheat. PMID:23630259

  5. Genome-Wide Association Mapping for Seedling and Adult Plant Resistance to Stripe Rust in Synthetic Hexaploid Wheat

    PubMed Central

    Makdis, Farid; Badebo, Ayele; Ogbonnaya, Francis C.

    2014-01-01

    Use of genetic diversity from related wild and domesticated species has made a significant contribution to improving wheat productivity. Synthetic hexaploid wheats (SHWs) exhibit natural genetic variation for resistance and/or tolerance to biotic and abiotic stresses. Stripe rust caused by (Puccinia striiformis f. sp. tritici; Pst), is an important disease of wheat worldwide. To characterise loci conferring resistance to stripe rust in SHWs, we conducted a genome-wide association study (GWAS) with a panel of 181 SHWs using the wheat 9K SNP iSelect array. The SHWs were evaluated for their response to the prevailing races of Pst at the seedling and adult plant stages, the latter in replicated field trials at two sites in Ethiopia in 2011. About 28% of the SHWs exhibited immunity at the seedling stage while 56% and 83% were resistant to Pst at the adult plant stage at Meraro and Arsi Robe, respectively. A total of 27 SNPs in nine genomic regions (1BS, 2AS, 2BL, 3BL, 3DL, 5A, 5BL, 6DS and 7A) were linked with resistance to Pst at the seedling stage, while 38 SNPs on 18 genomic regions were associated with resistance at the adult plant stage. Six genomic regions were commonly detected at both locations using a mixed linear model corrected for population structure, kinship relatedness and adjusted for false discovery rate (FDR). The loci on chromosome regions 1AS, 3DL, 6DS and 7AL appeared to be novel QTL; our results confirm that resynthesized wheat involving its progenitor species is a rich source of new stripe (yellow) rust resistance that may be useful in choosing SHWs and incorporating diverse yellow rust (YR) resistance loci into locally adapted wheat cultivars. PMID:25153126

  6. Progress towards the construction of a sequence-ready physical map of the 3AS chromosome arm of hexaploid wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The large genome size (~17 Gb), polyploid nature, and repetitive sequence content (>90%) of hexaploid wheat (Triticum aestivum) present a challenge for constructing physical maps, which are fundamental resources to aid genomic sequencing and annotation, and gene cloning. One approach to reduce the c...

  7. TYPES AND RATES OF SEQUENCE EVOLUTION AT HMW-GLUTENIN LOCUS IN HEXAPLOID WHEAT AND ITS ANCESTRAL GENOMES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Glu-1 locus, encoding the High Molecular Weight-glutenin protein subunits, controls bread-making quality in hexaploid wheat (Triticum aestivum) and represents a recently evolved region unique to Triticeae genomes. To understand the molecular evolution of this locus region, three orthologous Glu...

  8. Time-dependent changes in dough color in hexaploid wheat landraces differing in polyphenol oxidase activity.

    PubMed

    Bhattacharya, M; Luo, Q; Corke, H

    1999-09-01

    Time-dependent changes in the color of noodle sheets (using 2% NaCl or 1% alkaline salts in the formulation) made from 43 Iranian hexaploid wheat landrace accessions were measured. Pekar slick tests in water and in alkaline conditions were also carried out. A wide variation in color characteristics of the landraces was found, with L values of salted noodle sheets at 2 h ranging from 80.9 to 89.2 and b values of alkaline noodle sheets at 2 h ranging from 19.1 to 27.4, showing potential application in noodle wheat improvement programs. For initial rapid screening of samples it was observed that a single reading of the dough sheet after 2 h was adequate. The dough sheets should be kept at 5 degrees C during storage, to prevent microbiological activity in the dough, which would give erroneous results. The Pekar slick test results were not highly correlated to color measurements on the dough, so this test is not recommended for screening for noodle color potential in landraces. PMID:10552688

  9. Variation of floret fertility in hexaploid wheat revealed by tiller removal

    PubMed Central

    Guo, Zifeng

    2015-01-01

    Grain number per spike, which is greatly influenced by floret fertility, is an important trait of wheat (Triticum aestivum L.) yield. Maximum floret primordia, fertile floret, and final grain number per spikelet are three crucial factors of floret fertility. Floral degradation plays a critical role in determining these three floret fertility-related traits. Twelve hexaploid spring wheat genotypes were selected to investigate the influence of detillering on floral degradation and floret fertility-related traits in the field and greenhouse. Notably, the green anther stage was found to consistently have the maximum floret primordia number. Visible floral degradation, however, was observed to occur at several floral developmental stages, specifically from green anther stage to anthesis. Detillering was able to delay floral degradation in most cases and was evidently highly associated with increased maximum floret primordia, fertile floret, and final grain number per spikelet, with only a few exceptions. Thermal time required for each floral developmental stage was overall not influenced by detillering. These data hereby reveal a predominant spikelet fertility pattern along the spike in which the number of fertile florets per spikelet at anthesis becomes developmentally confined. PMID:26157170

  10. Variation of floret fertility in hexaploid wheat revealed by tiller removal.

    PubMed

    Guo, Zifeng; Schnurbusch, Thorsten

    2015-09-01

    Grain number per spike, which is greatly influenced by floret fertility, is an important trait of wheat (Triticum aestivum L.) yield. Maximum floret primordia, fertile floret, and final grain number per spikelet are three crucial factors of floret fertility. Floral degradation plays a critical role in determining these three floret fertility-related traits. Twelve hexaploid spring wheat genotypes were selected to investigate the influence of detillering on floral degradation and floret fertility-related traits in the field and greenhouse. Notably, the green anther stage was found to consistently have the maximum floret primordia number. Visible floral degradation, however, was observed to occur at several floral developmental stages, specifically from green anther stage to anthesis. Detillering was able to delay floral degradation in most cases and was evidently highly associated with increased maximum floret primordia, fertile floret, and final grain number per spikelet, with only a few exceptions. Thermal time required for each floral developmental stage was overall not influenced by detillering. These data hereby reveal a predominant spikelet fertility pattern along the spike in which the number of fertile florets per spikelet at anthesis becomes developmentally confined. PMID:26157170

  11. Using the Hexaploid Nature of Wheat To Create Variability in Starch Characteristics.

    PubMed

    Inokuma, Takayuki; Vrinten, Patricia; Shimbata, Tomoya; Sunohara, Ai; Ito, Hiroyuki; Saito, Mika; Taniguchi, Yoshinori; Nakamura, Toshiki

    2016-02-01

    In hexaploid crops, such as bread wheat, it should be possible to fine-tune phenotypic traits by identifying wild-type and null genes from each of the three genomes and combining them in a calculated manner. Here, we demonstrate this with gene combinations for two starch synthesis genes, SSIIa and GBSSI. Lines with inactive copies of both enzymes show a very dramatic change in phenotype, so to create intermediate phenotypes, we used marker-assisted selection to develop near-isogenic lines (NILs) carrying homozygous combinations of null alleles. For both genes, gene dosage effects follow the order B > D ? A; therefore, we completed detailed analysis of starch characteristics for NIL 3-3, which is null for the B-genome copy of the SSIIa and GBSSI genes, and NIL 5-5, which has null mutations in the B- and D-genome-encoded copies of both of these genes. The effects of the combinations on phenotypic traits followed the order expected on the basis of genotype, with NIL 5-5 showing the largest differences from the wild type, while NIL 3-3 characteristics were intermediate between NIL 5-5 and the wild type. Differences among genotypes were significant for many starch characteristics, including percent amylose, chain length distribution, gelatinization temperature, retrogradation, and pasting properties, and these differences appeared to translate into improvements in end-product quality, since bread made from type 5-5 flour showed a 3 day lag in staling. PMID:26808423

  12. Variability and genetics of spacer DNA sequences between the ribosomal-RNA genes of hexaploid wheat (Triticum aestivum).

    PubMed

    May, C E; Appels, R

    1987-09-01

    Using restriction enzyme digests of genomic DNA extracted from the leaves of 25 hexaploid wheat (Triticum aestivum L. em. Thell.) cultivars and their hybrids, restriction fragment length polymorphisms of the spacer DNA which separates the ribosomal-RNA genes have been examined. (From one to three thousand of these genes are borne on chromosomes 1B and 6B of hexaploid wheat). The data show that there are three distinct alleles of the 1B locus, designated Nor-B1a, Nor-B1b, and Nor-B1c, and at least five allelic variants of the 6B locus, designated Nor-B2a, Nor-B2b, Nor-B2c, Nor-B2d, and Nor-B2e. A further, previously reported allele on 6B has been named Nor-B2f. Chromosome 5D has only one allelic variant, Nor-D3. Whereas the major spacer variants of the 1B alleles apparently differ by the loss or gain of one or two of the 133 bp sub-repeat units within the spacer DNA, the 6B allelic variants show major differences in their compositions and lengths. This may be related to the greater number of rDNA repeat units at this locus. The practical implications of these differences and their application to wheat breeding are discussed. PMID:24240218

  13. Identification of Novel QTL for Seeding and Adult Plant Leaf Rust Resistance in a Wheat Doubled Haploid Population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pyramiding of genes that confer partial resistance is a method for developing wheat (Triticum aestivum L.) cultivars with durable resistance to leaf rust caused by Puccinia triticina. In this research, a doubled haploid (DH) population derived from the cross between the synthetic hexaploid wheat (S...

  14. Population divergence in the wheat leaf rust fungus Puccinia triticina is correlated with wheat evolution.

    PubMed

    Liu, M; Rodrigue, N; Kolmer, J

    2014-04-01

    Co-evolution of fungal pathogens with their host species during the domestication of modern crop varieties has likely affected the current genetic divergence of pathogen populations. The objective of this study was to determine if the evolutionary history of the obligate rust pathogen on wheat, Puccinia triticina, is correlated with adaptation to hosts with different ploidy levels. Sequence data from 15 loci with different levels of polymorphism were generated. Phylogenetic analyses (parsimony, Bayesian, maximum likelihood) showed the clear initial divergence of P. triticina isolates collected from Aegilops speltoides (the likely B genome donor of modern wheat) in Israel from the other isolates that were collected from tetraploid (AB genomes) durum wheat and hexaploid (ABD genomes) common wheat. Coalescence-based genealogy samplers also indicated that P. triticina on A. speltoides, diverged initially, followed by P. triticina isolates from durum wheat in Ethiopia and then by isolates from common wheat. Isolates of P. triticina found worldwide on cultivated durum wheat were the most recently coalesced and formed a clade nested within the isolates from common wheat. By a relative time scale, the divergence of P. triticinia as delimited by host specificity appears very recent. Significant reciprocal gene flow between isolates from common wheat and isolates from durum wheat that are found worldwide was detected, in addition to gene flow from isolates on common wheat to isolates on durum wheat in Ethiopia. PMID:24301080

  15. Identification and independent validation of a stable yield and thousand grain weight QTL on chromosome 6A of hexaploid wheat (Triticum aestivum L.)

    PubMed Central

    2014-01-01

    Background Grain yield in wheat is a polygenic trait that is influenced by environmental and genetic interactions at all stages of the plant’s growth. Yield is usually broken down into three components; number of spikes per area, grain number per spike, and grain weight (TGW). In polyploid wheat, studies have identified quantitative trait loci (QTL) which affect TGW, yet few have been validated and fine-mapped using independent germplasm, thereby having limited impact in breeding. Results In this study we identified a major QTL for TGW, yield and green canopy duration on wheat chromosome 6A of the Spark x Rialto population, across 12 North European environments. Using independent germplasm in the form of BC2 and BC4 near isogenic lines (NILs), we validated the three QTL effects across environments. In four of the five experiments the Rialto 6A introgression gave significant improvements in yield (5.5%) and TGW (5.1%), with morphometric measurements showing that the increased grain weight was a result of wider grains. The extended green canopy duration associated with the high yielding/TGW Rialto allele was comprised of two independent effects; earlier flowering and delayed final maturity, and was expressed stably across the five environments. The wheat homologue (TaGW2) of a rice gene associated with increased TGW and grain width was mapped within the QTL interval. However, no polymorphisms were identified in the coding sequence between the parents. Conclusion The discovery and validation through near-isogenic lines of robust QTL which affect yield, green canopy duration, thousand grain weight, and grain width on chromosome 6A of hexaploid wheat provide an important first step to advance our understanding of the genetic mechanisms regulating the complex processes governing grain size and yield in polyploid wheat. PMID:25034643

  16. [Analysis of wheat and rye semidwarfing gene distribution in spring hexaploid triticale (Triticosecale Wittm.) varieties and lines].

    PubMed

    Korshunova, A D; Divashchuk, M G; Solov'ev, A A; Karlov, G I

    2015-03-01

    A collection of spring hexaploid triticale varieties and promising breeding lines has been examined for the presence of wheat Rht-B1b, Rht-B1e, and Rht8c semidwarfing genes and the rye Hl semidwarfing gene. It was discovered in spring triticale that these semidwarfing genes are represented by only one, the Rht-B1b wheat gene. The presence of this gene is associated with shortening of spring triticale plants by 28 cm on average, which constituted 26% of their initial height. Rht-B1b was found in all of the studied commercial varieties of spring triticale, which rendered it possible to conclude that plant height reduction is a necessary condition for increasing the competitiveness of this crop culture. PMID:26027372

  17. Whole genome QTL analysis of Stagonospora nodorum blotch resistance and validation of the SnTox4-Snn4 interaction in hexaploid wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Abeysekara, N.S., Faris, J.D., Chao, S., McClean, P.E., and Friesen, T.L. 201_. Whole genome QTL analysis of Stagonospora nodorum blotch resistance and validation of the SnTox4- Snn4 interaction in hexaploid wheat. Phytopathology Necrotrophic effectors (also known as host-selective toxins) are impor...

  18. Genome-wide association for grain morphology in synthetic hexaploid wheats using digital imaging analysis

    PubMed Central

    2014-01-01

    Background Grain size and shape greatly influence grain weight which ultimately enhances grain yield in wheat. Digital imaging (DI) based phenomic characterization can capture the three dimensional variation in grain size and shape than has hitherto been possible. In this study, we report the results from using digital imaging of grain size and shape to understand the relationship among different components of this trait, their contribution to enhance grain weight, and to identify genomic regions (QTLs) controlling grain morphology using genome wide association mapping with high density diversity array technology (DArT) and allele-specific markers. Results Significant positive correlations were observed between grain weight and grain size measurements such as grain length (r = 0.43), width, thickness (r = 0.64) and factor from density (FFD) (r = 0.69). A total of 231 synthetic hexaploid wheats (SHWs) were grouped into five different sub-clusters by Bayesian structure analysis using unlinked DArT markers. Linkage disequilibrium (LD) decay was observed among DArT loci > 10 cM distance and approximately 28% marker pairs were in significant LD. In total, 197 loci over 60 chromosomal regions and 79 loci over 31 chromosomal regions were associated with grain morphology by genome wide analysis using general linear model (GLM) and mixed linear model (MLM) approaches, respectively. They were mainly distributed on homoeologous group 2, 3, 6 and 7 chromosomes. Twenty eight marker-trait associations (MTAs) on the D genome chromosomes 2D, 3D and 6D may carry novel alleles with potential to enhance grain weight due to the use of untapped wild accessions of Aegilops tauschii. Statistical simulations showed that favorable alleles for thousand kernel weight (TKW), grain length, width and thickness have additive genetic effects. Allelic variations for known genes controlling grain size and weight, viz. TaCwi-2A, TaSus-2B, TaCKX6-3D and TaGw2-6A, were also associated with TKW, grain width and thickness. In silico functional analysis predicted a range of biological functions for 32 DArT loci and receptor like kinase, known to affect plant development, appeared to be common protein family encoded by several loci responsible for grain size and shape. Conclusion Conclusively, we demonstrated the application and integration of multiple approaches including high throughput phenotyping using DI, genome wide association studies (GWAS) and in silico functional analysis of candidate loci to analyze target traits, and identify candidate genomic regions underlying these traits. These approaches provided great opportunity to understand the breeding value of SHWs for improving grain weight and enhanced our deep understanding on molecular genetics of grain weight in wheat. PMID:24884376

  19. Construction and Characterization of a Bacterial Artificial Chromosome Library for the Hexaploid Wheat Line 92R137

    PubMed Central

    Yuan, Fengping; Xu, Xin; Shi, Xue; Zhuang, Hua; Wang, Zhonghua; Huang, Lili; Han, Dejun; Kang, Zhensheng

    2014-01-01

    For map-based cloning of genes conferring important traits in the hexaploid wheat line 92R137, a bacterial artificial chromosome (BAC) library, including two sublibraries, was constructed using the genomic DNA of 92R137 digested with restriction enzymes HindIII and BamHI. The BAC library was composed of total 765,696 clones, of which 390,144 were from the HindIII digestion and 375,552 from the BamHI digestion. Through pulsed-field gel electrophoresis (PFGE) analysis of 453 clones randomly selected from the HindIII sublibrary and 573 clones from the BamHI sublibrary, the average insert sizes were estimated as 129 and 113 kb, respectively. Thus, the HindIII sublibrary was estimated to have a 3.01-fold coverage and the BamHI sublibrary a 2.53-fold coverage based on the estimated hexaploid wheat genome size of 16,700 Mb. The 765,696 clones were arrayed in 1,994 384-well plates. All clones were also arranged into plate pools and further arranged into 5-dimensional (5D) pools. The probability of identifying a clone corresponding to any wheat DNA sequence (such as gene Yr26 for stripe rust resistance) from the library was estimated to be more than 99.6%. Through polymerase chain reaction screening the 5D pools with Xwe173, a marker tightly linked to Yr26, six BAC clones were successfully obtained. These results demonstrate that the BAC library is a valuable genomic resource for positional cloning of Yr26 and other genes of interest. PMID:24895618

  20. An Ethylmethane Sulfonate Mutant Resource in Pre-Green Revolution Hexaploid Wheat

    PubMed Central

    Dhaliwal, Amandeep K.; Mohan, Amita; Sidhu, Gaganjot; Maqbool, Rizwana; Gill, Kulvinder S.

    2015-01-01

    Mutagenesis is a powerful tool used for studying gene function as well as for crop improvement. It is regaining popularity because of the development of effective and cost efficient methods for high-throughput mutation detection. Selection for semi-dwarf phenotype during green revolution has reduced genetic diversity including that for agronomically desirable traits. Most of the available mutant populations in wheat (Triticum aestivum L.) were developed in post-green revolution cultivars. Besides the identification and isolation of agronomically important alleles in the mutant population of pre-green revolution cultivar, this population can be a vital resource for expanding the genetic diversity for wheat breeding. Here we report an Ethylmethane Sulfonate (EMS) generated mutant population consisting of 4,180 unique mutant plants in a pre-green revolution spring wheat cultivar ‘Indian’. Released in early 1900s, ‘Indian’ is devoid of any known height-reducing mutations. Unique mutations were captured by proceeding with single M2 seed from each of the 4,180 M1 plants. Mutants for various phenotypic traits were identified by detailed phenotyping for altered morphological and agronomic traits on M2 plants in the greenhouse and M3 plants in the field. Of the 86 identified mutants, 75 (87%) were phenotypically stable at the M4 generation. Among the observed phenotypes, variation in plant height was the most frequent followed by the leaf morphology. Several mutant phenotypes including looped peduncle, crooked plant morphology, ‘gritty’ coleoptiles, looped lower internodes, and burnt leaf tips are not reported in other plant species. Considering the extent and diversity of the observed mutant phenotypes, this population appears to be a useful resource for the forward and reverse genetic studies. This resource is available to the scientific community. PMID:26678261

  1. An Ethylmethane Sulfonate Mutant Resource in Pre-Green Revolution Hexaploid Wheat.

    PubMed

    Dhaliwal, Amandeep K; Mohan, Amita; Sidhu, Gaganjot; Maqbool, Rizwana; Gill, Kulvinder S

    2015-01-01

    Mutagenesis is a powerful tool used for studying gene function as well as for crop improvement. It is regaining popularity because of the development of effective and cost efficient methods for high-throughput mutation detection. Selection for semi-dwarf phenotype during green revolution has reduced genetic diversity including that for agronomically desirable traits. Most of the available mutant populations in wheat (Triticum aestivum L.) were developed in post-green revolution cultivars. Besides the identification and isolation of agronomically important alleles in the mutant population of pre-green revolution cultivar, this population can be a vital resource for expanding the genetic diversity for wheat breeding. Here we report an Ethylmethane Sulfonate (EMS) generated mutant population consisting of 4,180 unique mutant plants in a pre-green revolution spring wheat cultivar 'Indian'. Released in early 1900s, 'Indian' is devoid of any known height-reducing mutations. Unique mutations were captured by proceeding with single M2 seed from each of the 4,180 M1 plants. Mutants for various phenotypic traits were identified by detailed phenotyping for altered morphological and agronomic traits on M2 plants in the greenhouse and M3 plants in the field. Of the 86 identified mutants, 75 (87%) were phenotypically stable at the M4 generation. Among the observed phenotypes, variation in plant height was the most frequent followed by the leaf morphology. Several mutant phenotypes including looped peduncle, crooked plant morphology, 'gritty' coleoptiles, looped lower internodes, and burnt leaf tips are not reported in other plant species. Considering the extent and diversity of the observed mutant phenotypes, this population appears to be a useful resource for the forward and reverse genetic studies. This resource is available to the scientific community. PMID:26678261

  2. Cloning and comparative analysis of carotenoid β-hydroxylase genes provides new insights into carotenoid metabolism in tetraploid (Triticum turgidum ssp. durum) and hexaploid (Triticum aestivum) wheat grains

    PubMed Central

    Qin, Xiaoqiong; Zhang, Wenjun; Dubcovsky, Jorge; Tian, Li

    2016-01-01

    Carotenoid β-hydroxylases attach hydroxyl groups to the β-ionone rings (β-rings) of carotenoid substrates, resulting in modified structures and functions of carotenoid molecules. We cloned and characterized two genes (each with three homeologs), HYD1 and HYD2, which encode β-hydroxylases in wheat. The results from bioinformatic and nested degenerate PCR analyses collectively suggest that HYD1 and HYD2 may represent the entire complement of non-heme di-iron β-hydroxylases in wheat. The homeologs of wheat HYDs exhibited major β-ring and minor ε-ring hydroxylation activities in carotenoid-accumulating E. coli strains. Distinct expression patterns were observed for different HYD genes and homeologs in vegetative tissues and developing grains of tetraploid and hexaploid wheat, suggesting their functional divergence and differential regulatory control in tissue-, grain development-, and ploidy-specific manners. An intriguing observation was that the expression of HYD1, particularly HYD-B1, reached highest levels at the last stage of tetraploid and hexaploid grain development, suggesting that carotenoids (at least xanthophylls) were still actively synthesized in mature grains. This result challenges the common perception that carotenoids are simply being turned over during wheat grain development after their initial biosynthesis at the early grain development stages. Overall, this improved understanding of carotenoid biosynthetic gene expression and carotenoid metabolism in wheat grains will contribute to the improvement of the nutritional value of wheat grains for human consumption. PMID:23015203

  3. The CBF gene family in hexaploid wheat and its relationship to the phylogenetic complexity of cereal CBFs

    PubMed Central

    Badawi, Mohamed; Boucho, Barbara; Houde, Mario; Sarhan, Fathey

    2007-01-01

    Most temperate plants tolerate both chilling and freezing temperatures whereas many species from tropical regions suffer chilling injury when exposed to temperatures slightly above freezing. Cold acclimation induces the expression of cold-regulated genes needed to protect plants against freezing stress. This induction is mediated, in part, by the CBF transcription factor family. To understand the evolution and function of this family in cereals, we identified and characterized 15 different CBF genes from hexaploid wheat. Our analyses reveal that wheat species, T. aestivum and T. monococcum, may contain up to 25 different CBF genes, and that Poaceae CBFs can be classified into 10 groups that share a common phylogenetic origin and similar structural characteristics. Six of these groups (IIIc, IIId, IVa, IVb, IVc and IVd) are found only in the Pooideae suggesting they represent the CBF response machinery that evolved recently during colonization of temperate habitats. Expression studies reveal that five of the Pooideae-specific groups display higher constitutive and low temperature inducible expression in the winter cultivar, and a diurnal regulation pattern during growth at warm temperature. The higher constitutive and inducible expression within these CBF groups is an inherited trait that may play a predominant role in the superior low temperature tolerance capacity of winter cultivars and possibly be a basis of genetic variability in freezing tolerance within the Pooideae subfamily. Electronic supplementary material The online version of this article (doi:10.1007/s00438-006-0206-9) contains supplementary material, which is available to authorized users. PMID:17285309

  4. Marker Development and Saturation Mapping of the Tan Spot Ptr ToxB Sensitivity locus Tsc2 in Hexaploid Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ptr ToxB is a host-selective toxin produced by the tan spot fungus that induces chlorosis in wheat lines harboring the Tsc2 gene, which was previously located to chromosome arm 2BS in tetraploid wheat. In this study, molecular mapping in a recombinant inbred (RI) population derived from a cross betw...

  5. ANEUPLOIDY DETECTION WITH A SHORT-TERM HEXAPLOID WHEAT ASSAY (JOURNAL VERSION)

    EPA Science Inventory

    A novel assay for the identification of agents causing aneuploidy is described. This assay takes advantage of allohexaploid wheat in which monosomic and nullisomic cell lineages can be genetically detected. The wheat strain used is homozygous for a pair of recissive alleles (v1) ...

  6. [Development and study of spring bread wheat variety Pamyati Maystrenko with introgression of genetic material from synthetic hexaploid Triticum timopheevii zhuk. x Aegilops tauschii Coss].

    PubMed

    Laikova, L I; Belan, I A; Badaeva, E D; Posseeva, L P; Shepelev, S S; Shumny, V K; Pershina, L A

    2013-01-01

    Synthetic hexaploids are bridges for transferring new genes that determine resistance to stress factors from wild-type species to bread wheat. In the present work, the method of developing the spring bread wheat variety Pamyati Maystrenko and the results of its study are described. This variety was obtained using one of the immune lines produced earlier via the hybridization of the spring bread wheat variety Saratovskaya 29 with the synthetic hexaploid T. timopheevii Zhuk. x Ae. tauschii Coss. The C-staining of chromosomes in the Pamyati Maystrenko variety revealed substitutions of 2B and 6B chromosomes by the homeologous chromosomes of the G genome of T. timopheevii and the substitution of chromosome 1D by an orthologous chromosome ofAe. tauschii. It was found that this variety is characterized by resistance to leaf and stem rust, powdery mildew, and loose smut as well as by high grain and bread-making qualities. The role of the alien genetic material introgressed into the bread-wheat genome in the expression of adaptive and economically valuable traits in the Pamyati Maystrenko variety is discussed. PMID:23662428

  7. Genome-wide identification and expression characterization of ABCC-MRP transporters in hexaploid wheat

    PubMed Central

    Bhati, Kaushal K.; Sharma, Shivani; Aggarwal, Sipla; Kaur, Mandeep; Shukla, Vishnu; Kaur, Jagdeep; Mantri, Shrikant; Pandey, Ajay K.

    2015-01-01

    The ABCC multidrug resistance associated proteins (ABCC-MRP), a subclass of ABC transporters are involved in multiple physiological processes that include cellular homeostasis, metal detoxification, and transport of glutathione-conjugates. Although they are well-studied in humans, yeast, and Arabidopsis, limited efforts have been made to address their possible role in crop like wheat. In the present work, 18 wheat ABCC-MRP proteins were identified that showed the uniform distribution with sub-families from rice and Arabidopsis. Organ-specific quantitative expression analysis of wheat ABCC genes indicated significantly higher accumulation in roots (TaABCC2, TaABCC3, and TaABCC11 and TaABCC12), stem (TaABCC1), leaves (TaABCC16 and TaABCC17), flag leaf (TaABCC14 and TaABCC15), and seeds (TaABCC6, TaABCC8, TaABCC12, TaABCC13, and TaABCC17) implicating their role in the respective tissues. Differential transcript expression patterns were observed for TaABCC genes during grain maturation speculating their role during seed development. Hormone treatment experiments indicated that some of the ABCC genes could be transcriptionally regulated during seed development. In the presence of Cd or hydrogen peroxide, distinct molecular expression of wheat ABCC genes was observed in the wheat seedlings, suggesting their possible role during heavy metal generated oxidative stress. Functional characterization of the wheat transporter, TaABCC13 a homolog of maize LPA1 confirms its role in glutathione-mediated detoxification pathway and is able to utilize adenine biosynthetic intermediates as a substrate. This is the first comprehensive inventory of wheat ABCC-MRP gene subfamily. PMID:26191068

  8. Rmg8, a New Gene for Resistance to Triticum Isolates of Pyricularia oryzae in Hexaploid Wheat.

    PubMed

    Anh, Vu Lan; Anh, Nguyen Tuan; Tagle, Analiza Grubanzo; Vy, Trinh Thi Phuong; Inoue, Yoshihiro; Takumi, Shigeo; Chuma, Izumi; Tosa, Yukio

    2015-12-01

    Blast, caused by Pyricularia oryzae, is one of the major diseases of wheat in South America. We identified a new gene for resistance to Triticum isolates of P. oryzae in common wheat 'S-615', and designated it "resistance to Magnaporthe grisea 8" (Rmg8). Rmg8 was assigned to chromosome 2B through molecular mapping with simple-sequence repeat markers. To identify an avirulence gene corresponding to Rmg8, Triticum isolate Br48 (avirulent on S-615) was crossed with 200R29 (virulent on S-615), an F1 progeny derived from a cross between an Eleusine isolate (MZ5-1-6) and Br48. Segregation analysis of their progeny revealed that avirulence of Br48 on S-615 was conditioned by a single gene, which was designated AVR-Rmg8. AVR-Rmg8 was closely linked to AVR-Rmg7, which corresponded to Rmg7 located on chromosome 2A of tetraploid wheat. PMID:26555672

  9. Breeding and Characterization of Hexaploid Wheats with Nil Levels of Grain Polyphenol Oxidase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polyphenol oxidase (PPO) is a ubiquitous enzyme in plants, responsible for many browning reactions and reduction of food product quality. In common (bread) wheat, PPO occurs in the external layers of grain, often is carried into flour via milling, and can be responsible for the discoloration of whe...

  10. Genetic maps of stem rust resistance gene Sr35 in diploid and hexaploid wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Puccinia graminis f. sp. tritici is the causal agent of stem rust of wheat. A new race designated TTKSK (also known as Ug99) has recently spread through East Africa, Yemen and on to Iran. TTKSK and its variants (TTKST and TTTSK) are virulent to most of the stem rust resistance genes currently deploy...

  11. A comparison of the levels of hydroxamic acids in Aegilops speltoides and a hexaploid wheat and effects on Rhopalosiphum padi behaviour and fecundity.

    PubMed

    Elek, Henriett; Smart, Lesley; Ahmad, S; Anda, Angla; Werner, C P; Pickett, J A

    2014-03-01

    Hydroxamic acids (HAs) are plant secondary metabolites produced by certain cereals, which have been found to be toxic to pest aphids in artificial diet assays. Previous studies have shown that tetraploid and hexaploid wheat varieties, the leaf tissues of which contained higher levels of these compounds than used in artificial diets, did not reduce aphid settling or fecundity. This current study reports findings on a high HA producing B genome accession of the diploid ancestor of wheat, Aegilops speltoides. We found that this accession does have a negative impact on aphid host selection and substantially reduces nymph production. Whole leaf tissue assays showed very high levels of HAs, well in excess of the toxic level determined in the artificial diet assays. Extraction of the apoplast fluid (AF) from this accession showed that the HA level is much lower than that of the whole tissue, but is still close to the artificial diet toxic level. Furthermore the HA level in the AF increases in response to aphid feeding. These observations could explain why hexaploid wheat remains susceptible to aphids, despite having whole leaf tissue HA levels in excess of the toxic levels determined in artificial diets. PMID:24561893

  12. Comparative analysis of physio-biochemical responses to cold stress in tetraploid and hexaploid wheat.

    PubMed

    Nejadsadeghi, Leila; Maali-Amiri, Reza; Zeinali, Hassan; Ramezanpour, Sanaz; Sadeghzade, Behzad

    2014-09-01

    The cellular changes induced by cold stress (CS) include responses that lead to oxidative stress and limits plant growth, metabolism, and productivity. In this study, responses of physio-biochemical to CS phases were comparatively studied in three genotypes of bread and durum wheats differing in sensitivity, two of them (Norstar, bread wheat and Gerdish, durum wheat) were tolerant to CS and the other one, SRN (durum wheat) was sensitive to CS. 14-day-old seedlings were subjected to CS (12 and 24 h) with or without cold acclimation (CA) phase. During CS, the elevated levels of electrolyte leakage index, contents of hydrogen peroxide (H2O2), and malondialdehyde in Norstar and Gerdish were lower than that of SRN plants. Positive correlation and co-regulation of reactive oxygen species (ROS) scavenging systems, superoxide dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase, and proline especially after CA phase suggested crucial role for holding back toxic ROS levels in CS phase. However, different activities of this system resulted in different intensities of oxidative stress in acclimated and non-acclimated plants. Our results showed that a CA phase induced oxidative stress tolerance by modulating antioxidative systems. These responses confirmed the existence of wide range of genetic capacity in durum wheat to increase cold tolerance particularly in Gerdish so that the sensitivity of SRN plants to CS was linearly correlated with the more decrease of antioxidant systems. These general responses may be a sign for associating other metabolites or enzymes activities to create partly tolerance against cold-induced oxidative stress. Eventually, assessing the dynamic of cell responses in short intervals after CS without CA phases profitably could be a novel path in plant stress response investigations in a short period of time. PMID:24691928

  13. Membrane fatty acid compositions and cold-induced responses in tetraploid and hexaploid wheats.

    PubMed

    Nejadsadeghi, Leila; Maali-Amiri, Reza; Zeinali, Hassan; Ramezanpour, Sanaz; Sadeghzade, Behzad

    2015-02-01

    Plant cells often increase cold tolerance by reprogramming their genes expression which results in adjusted metabolic alternations, a process enhanced under cold acclimation. In present study, we assessed the changes of membrane fatty acid compositions along with physio-biochemical indices like H2O2 and malondialdehyde (MDA) contents and lipoxygenase (LOX) activity during cold stress (CS) phases in acclimated and non-acclimated durum (SRN and Gerdish) and bread (Norstar) wheat genotypes. During thermal treatments, MDA was an end product of lipid peroxidation via oxidative stress (H2O2 content) rather than LOX activity. LOX activity plays a double role in mechanism of cold tolerance in wheat, particularly at severe stress. With increase in severity of CS especially in non-acclimated plants, LOX activity decreased along with an increase in MDA and other responses helped increase or maintaine unsaturated fatty acids (FAs) whereas in acclimated plants (moderate CS), increasing of LOX activity along with a decrease in MDA indicates probably its role in secondary metabolites like jasmonic acid signaling pathway. Significant increase of total FAs and particularly unsaturated FAs showed distinct cell endeavor to protect against CS in Norstar and Gerdish compared to SRN genotype. Results showed that an increase in double bond index and LOX activity and low MDA under CS could be reasons for plant cold tolerance. PMID:25266238

  14. Phenotyping pipeline reveals major seedling root growth QTL in hexaploid wheat.

    PubMed

    Atkinson, Jonathan A; Wingen, Luzie U; Griffiths, Marcus; Pound, Michael P; Gaju, Oorbessy; Foulkes, M John; Le Gouis, Jacques; Griffiths, Simon; Bennett, Malcolm J; King, Julie; Wells, Darren M

    2015-04-01

    Seedling root traits of wheat (Triticum aestivum L.) have been shown to be important for efficient establishment and linked to mature plant traits such as height and yield. A root phenotyping pipeline, consisting of a germination paper-based screen combined with image segmentation and analysis software, was developed and used to characterize seedling traits in 94 doubled haploid progeny derived from a cross between the winter wheat cultivars Rialto and Savannah. Field experiments were conducted to measure mature plant height, grain yield, and nitrogen (N) uptake in three sites over 2 years. In total, 29 quantitative trait loci (QTLs) for seedling root traits were identified. Two QTLs for grain yield and N uptake co-localize with root QTLs on chromosomes 2B and 7D, respectively. Of the 29 root QTLs identified, 11 were found to co-localize on 6D, with four of these achieving highly significant logarithm of odds scores (>20). These results suggest the presence of a major-effect gene regulating seedling root vigour/growth on chromosome 6D. PMID:25740921

  15. Phenotyping pipeline reveals major seedling root growth QTL in hexaploid wheat

    PubMed Central

    Atkinson, Jonathan A.; Wingen, Luzie U.; Griffiths, Marcus; Pound, Michael P.; Gaju, Oorbessy; Foulkes, M. John; Le Gouis, Jacques; Griffiths, Simon; Bennett, Malcolm J.; King, Julie; Wells, Darren M.

    2015-01-01

    Seedling root traits of wheat (Triticum aestivum L.) have been shown to be important for efficient establishment and linked to mature plant traits such as height and yield. A root phenotyping pipeline, consisting of a germination paper-based screen combined with image segmentation and analysis software, was developed and used to characterize seedling traits in 94 doubled haploid progeny derived from a cross between the winter wheat cultivars Rialto and Savannah. Field experiments were conducted to measure mature plant height, grain yield, and nitrogen (N) uptake in three sites over 2 years. In total, 29 quantitative trait loci (QTLs) for seedling root traits were identified. Two QTLs for grain yield and N uptake co-localize with root QTLs on chromosomes 2B and 7D, respectively. Of the 29 root QTLs identified, 11 were found to co-localize on 6D, with four of these achieving highly significant logarithm of odds scores (>20). These results suggest the presence of a major-effect gene regulating seedling root vigour/growth on chromosome 6D. PMID:25740921

  16. Comprehensive molecular characterization of the ?/?-gliadin multigene family in hexaploid wheat.

    PubMed

    Noma, Satoshi; Kawaura, Kanako; Hayakawa, Katsuyuki; Abe, Chikako; Tsuge, Noritaka; Ogihara, Yasunari

    2016-02-01

    To characterize the structure and expression of a large multigene family of ?/?-gliadin genes, 90 individual ?/?-gliadin genes harboring a promoter region were identified in the wheat cultivar Chinese Spring. These genes were classified into eleven groups by phylogenetic analysis, and the chromosomes they were derived from were determined. Of these genes, 50 had the basic ?/?-gliadin domains and six conserved cysteine residues and 16, 16 and 18 of them were, respectively, located on chromosome 6A, 6B and 6D. Six genes had an additional cysteine residue, suggesting that these ?/?-gliadins acquired the property of binding other proteins through intermolecular disulphide bands. Expression of ?/?-gliadin genes in developing seeds was measured by quantitative RT-PCR using group-specific primers over 3years. Expression patterns of these genes on the basis of accumulated temperature were similar among gene groups, whereas expression levels differed for the 3years. The expression of most ?/?-gliadin and other prolamin genes was correlated with the sunshine duration. On the other hand, although all ?/?-gliadin genes had a common E-box within the -300 promoter region, some genes showed a particular expression pattern with respect to the sunshine duration, similarly to gene encoding high-molecular weight glutenin subunits and endosperm enzymes. These observations suggested that expression of each ?/?-gliadin gene is differentially regulated by multiple regulatory factors. PMID:26159870

  17. A genome-wide analysis of the auxin/indole-3-acetic acid gene family in hexaploid bread wheat (Triticum aestivum L.)

    PubMed Central

    Qiao, Linyi; Zhang, Xiaojun; Han, Xiao; Zhang, Lei; Li, Xin; Zhan, Haixian; Ma, Jian; Luo, Peigao; Zhang, Wenping; Cui, Lei; Li, Xiaoyan; Chang, Zhijian

    2015-01-01

    The Auxin/indole-3-acetic acid (Aux/IAA) gene family plays key roles in the primary auxin-response process and controls a number of important traits in plants. However, the characteristics of the Aux/IAA gene family in hexaploid bread wheat (Triticum aestivum L.) have long been unknown. In this study, a comprehensive identification of the Aux/IAA gene family was performed using the latest draft genome sequence of the bread wheat Chinese Spring. Thirty-four Aux/IAA genes were identified, 30 of which have duplicated genes on the A, B or D sub-genome, with a total of 84 Aux/IAA sequences. These predicted Aux/IAA genes were non-randomly distributed in all the wheat chromosomes except for chromosome 2D. The information of wheat Aux/IAA proteins is also described. Based on an analysis of phylogeny, expression and adaptive evolution, we prove that the Aux/IAA family in wheat has been replicated twice in the two allopolyploidization events of bread wheat, when the tandem duplication also occurred. The duplicated genes have undergone an evolutionary process of purifying selection, resulting in the high conservation of copy genes among sub-genomes and functional redundancy among several members of the TaIAA family. However, functional divergence probably existed in most TaIAA members due to the diversity of the functional domain and expression pattern. Our research provides useful information for further research into the function of Aux/IAA genes in wheat. PMID:26483801

  18. mRNA and Small RNA Transcriptomes Reveal Insights into Dynamic Homoeolog Regulation of Allopolyploid Heterosis in Nascent Hexaploid Wheat[W][OPEN

    PubMed Central

    Li, Aili; Liu, Dengcai; Wu, Jun; Zhao, Xubo; Hao, Ming; Geng, Shuaifeng; Yan, Jun; Jiang, Xiaoxue; Zhang, Lianquan; Wu, Junyan; Yin, Lingjie; Zhang, Rongzhi; Wu, Liang; Zheng, Youliang; Mao, Long

    2014-01-01

    Nascent allohexaploid wheat may represent the initial genetic state of common wheat (Triticum aestivum), which arose as a hybrid between Triticum turgidum (AABB) and Aegilops tauschii (DD) and by chromosome doubling and outcompeted its parents in growth vigor and adaptability. To better understand the molecular basis for this success, we performed mRNA and small RNA transcriptome analyses in nascent allohexaploid wheat and its following generations, their progenitors, and the natural allohexaploid cultivar Chinese Spring, with the assistance of recently published A and D genome sequences. We found that nonadditively expressed protein-coding genes were rare but relevant to growth vigor. Moreover, a high proportion of protein-coding genes exhibited parental expression level dominance, with genes for which the total homoeolog expression level in the progeny was similar to that in T. turgidum potentially participating in development and those with similar expression to that in Ae. tauschii involved in adaptation. In addition, a high proportion of microRNAs showed nonadditive expression upon polyploidization, potentially leading to differential expression of important target genes. Furthermore, increased small interfering RNA density was observed for transposable element–associated D homoeologs in the allohexaploid progeny, which may account for biased repression of D homoeologs. Together, our data provide insights into small RNA–mediated dynamic homoeolog regulation mechanisms that may contribute to heterosis in nascent hexaploid wheat. PMID:24838975

  19. Molecular characterization of the AP2-like Q gene homoeoallele on chromosome 5D in hexaploid wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Q gene of wheat is responsible for many morphological traits associated with domestication. Q is located on wheat chromosome 5A and it is a member of the AP2 class of transcription factors. Genotypes harboring the q allele on chromosome 5A have speltoid spikes, which include non free-threshing...

  20. Molecular characterization of the puroindoline-a and b alleles in synthetic hexaploid wheats and in silico functional and structural insights into Pina-D1.

    PubMed

    Ali, Iftikhar; Sardar, Zainab; Rasheed, Awais; Mahmood, Tariq

    2015-07-01

    Kernel hardness determined by two tightly linked Puroindoline genes, Pina-D1 and Pinb-D1, located on chromosome 5DS define commercially important characteristics, uses, major grades and export markets of wheat. This study was conducted to characterize Pina-D1 and Pinb-D1 alleles, in fifteen synthetic hexaploid wheats (SHWs) and its relation with grain hardness. Additionally, in silico functional analyses of puroindoline-a protein was conducted for better understanding of their putative importance in grain quality. Six different Pina-D1 alleles were identified in the SHWs, of which three i.e. Pina-D1a, Pina-D1c and Pina-D1d were already known whereas the other three had new sequence polymorphisms and were designated as Pina-D1w, Pina-D1x and Pina-D1y. Three different Pinb-D1 alleles were identified which have been reported earlier and no novel sequence polymorphism was detected. It was concluded that despite some primary, secondary and 3D structure variations, ligand binding sites and disulfide bonds discrepancies, the main features of PINA, i.e. the tryptophan-rich domain, the cysteine backbone, the signal peptide and basic identity of the proteins were all conserved. In silico analysis showed that puroindolines having binding capacity with small parts of prolamins causing celiac disease of human, however their potential role is not obvious. Conclusively, the new Pina-D1 alleles with modest effect on grain hardness, and insight into their functional and structural characteristics are important findings and their putative role in celiac disease require further studies to validate. PMID:25865523

  1. A highly conserved gene island of three genes on chromosome 3B of hexaploid wheat: diverse gene function and genomic structure maintained in a tightly linked block

    PubMed Central

    2010-01-01

    Background The complexity of the wheat genome has resulted from waves of retrotransposable element insertions. Gene deletions and disruptions generated by the fast replacement of repetitive elements in wheat have resulted in disruption of colinearity at a micro (sub-megabase) level among the cereals. In view of genomic changes that are possible within a given time span, conservation of genes between species tends to imply an important functional or regional constraint that does not permit a change in genomic structure. The ctg1034 contig completed in this paper was initially studied because it was assigned to the Sr2 resistance locus region, but detailed mapping studies subsequently assigned it to the long arm of 3B and revealed its unusual features. Results BAC shotgun sequencing of the hexaploid wheat (Triticum aestivum cv. Chinese Spring) genome has been used to assemble a group of 15 wheat BACs from the chromosome 3B physical map FPC contig ctg1034 into a 783,553 bp genomic sequence. This ctg1034 sequence was annotated for biological features such as genes and transposable elements. A three-gene island was identified among >80% repetitive DNA sequence. Using bioinformatics analysis there were no observable similarity in their gene functions. The ctg1034 gene island also displayed complete conservation of gene order and orientation with syntenic gene islands found in publicly available genome sequences of Brachypodium distachyon, Oryza sativa, Sorghum bicolor and Zea mays, even though the intergenic space and introns were divergent. Conclusion We propose that ctg1034 is located within the heterochromatic C-band region of deletion bin 3BL7 based on the identification of heterochromatic tandem repeats and presence of significant matches to chromodomain-containing gypsy LTR retrotransposable elements. We also speculate that this location, among other highly repetitive sequences, may account for the relative stability in gene order and orientation within the gene island. Sequence data from this article have been deposited with the GenBank Data Libraries under accession no. GQ422824 PMID:20507561

  2. Molecular Characterization of TaFAR1 Involved in Primary Alcohol Biosynthesis of Cuticular Wax in Hexaploid Wheat.

    PubMed

    Wang, Yong; Wang, Meiling; Sun, Yulin; Hegebarth, Daniela; Li, Tingting; Jetter, Reinhard; Wang, Zhonghua

    2015-10-01

    Cuticular waxes are complex mixtures of very long chain (VLC) fatty acids and their derivatives in which primary alcohols are the most abundant components in the leaf surface of common wheat (Triticum aestivum L.). However, the genes involved in primary alcohol biosynthesis in wheat are still largely unknown. Here we identified, via a homology-based approach, the TaFAR1 gene belonging to the fatty acyl-CoA reductases (FARs) from wheat. Heterologous expression of TaFAR1 in yeast (Saccharomyces cerevisiae) and in the Arabidopsis (Arabidopsis thaliana) cer4-3 mutant afforded production of C22 primary alcohol and C22-C24 primary alcohols, respectively, and transgenic expression of TaFAR1 in tomato (Solanum lycopersicum) cv MicroTom leaves and fruits resulted in the accumulation of C26-C30 primary alcohols and C30-C34 primary alcohols, respectively. The TaFAR1 protein was localized to the endoplasmic reticulum (ER) in rice (Oryza sativa L.) leaf protoplasts. Moreover, the TaFAR1 expression pattern across various organs correlated with the levels of primary alcohols accumulating in corresponding waxes, and with the presence of platelet-shaped epicuticular wax crystals formed by primary alcohols. A nullisomic-tetrasomic wheat line lacking TaFAR1 had significantly reduced levels of primary alcohols in its leaf blade and anther wax. TaFAR1 was located on chromosome 4AL and appeared to be highly conserved, with only one haplotype among 32 wheat cultivars. Finally, TaFAR1 expression was induced by drought and cold stress in an ABA-dependent manner. Taken together, our results show that TaFAR1 is an active enzyme forming primary alcohols destined for the wheat cuticle. PMID:26220905

  3. Genome-wide comparative diversity uncovers multiple targets of selection for improvement in hexaploid wheat landrace and cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Domesticated crops have experienced strong human-driven selection aimed at the development of improved varieties adapted to local conditions. To detect regions of the wheat genome subject to selection during improvement, we developed a high-throughput array to interrogate 9,000 gene-associated DNA m...

  4. Genome-Wide Association Mapping for Resistance to Leaf and Stripe Rust in Winter-Habit Hexaploid Wheat Landraces

    PubMed Central

    Kertho, Albert; Mamidi, Sujan; Bonman, J. Michael; McClean, Phillip E.; Acevedo, Maricelis

    2015-01-01

    Leaf rust, caused by Puccinia triticina (Pt), and stripe rust, caused by P. striiformis f. sp. tritici (Pst), are destructive foliar diseases of wheat worldwide. Breeding for disease resistance is the preferred strategy of managing both diseases. The continued emergence of new races of Pt and Pst requires a constant search for new sources of resistance. Here we report a genome-wide association analysis of 567 winter wheat (Triticum aestivum) landrace accessions using the Infinium iSelect 9K wheat SNP array to identify loci associated with seedling resistance to five races of Pt (MDCL, MFPS, THBL, TDBG, and TBDJ) and one race of Pst (PSTv-37) frequently found in the Northern Great Plains of the United States. Mixed linear models identified 65 and eight significant markers associated with leaf rust and stripe rust, respectively. Further, we identified 31 and three QTL associated with resistance to Pt and Pst, respectively. Eleven QTL, identified on chromosomes 3A, 4A, 5A, and 6D, are previously unknown for leaf rust resistance in T. aestivum. PMID:26076040

  5. Comparative High-Resolution Mapping of the Wax Inhibitors Iw1 and Iw2 in Hexaploid Wheat

    PubMed Central

    Han, Jun; Zhao, Xiaojie; Ouyang, Shuhong; Liang, Yong; Zhang, Dong; Wang, Zhenzhong; Wu, Qiuhong; Xie, Jingzhong; Cui, Yu; Peng, Huiru; Sun, Qixin; Liu, Zhiyong

    2013-01-01

    The wax (glaucousness) on wheat leaves and stems is mainly controlled by two sets of genes: glaucousness loci (W1 and W2) and non-glaucousness loci (Iw1 and Iw2). The non-glaucousness (Iw) loci act as inhibitors of the glaucousness loci (W). High-resolution comparative genetic linkage maps of the wax inhibitors Iw1 originating from Triticum dicoccoides, and Iw2 from Aegilops tauschii were developed by comparative genomics analyses of Brachypodium, sorghum and rice genomic sequences corresponding to the syntenic regions of the Iw loci in wheat. Eleven Iw1 and eight Iw2 linked EST markers were developed and mapped to linkage maps on the distal regions of chromosomes 2BS and 2DS, respectively. The Iw1 locus mapped within a 0.96 cM interval flanked by the BE498358 and CA499581 EST markers that are collinear with 122 kb, 202 kb, and 466 kb genomic regions in the Brachypodium 5S chromosome, the sorghum 6S chromosome and the rice 4S chromosome, respectively. The Iw2 locus was located in a 4.1 to 5.4-cM interval in chromosome 2DS that is flanked by the CJ886319 and CJ519831 EST markers, and this region is collinear with a 2.3 cM region spanning the Iw1 locus on chromosome 2BS. Both Iw1 and Iw2 co-segregated with the BF474014 and CJ876545 EST markers, indicating they are most likely orthologs on 2BS and 2DS. These high-resolution maps can serve as a framework for chromosome landing, physical mapping and map-based cloning of the wax inhibitors in wheat. PMID:24376835

  6. Mapping and validation of Yr48 and other QTL conferring partial resistance to broadly virulent post-2000 North American races of stripe rust in hexaploid wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A mapping population of 188 recombinant inbred lines developed from a cross between UC1110, an adapted California spring wheat, and PI610750, a synthetic derivative from CIMMYT's wide-cross program, was evaluated for its response to current California races of stripe rust (Puccinia striiformis f.sp....

  7. Population- and genome-specific patterns of linkage disequilibrium and SNP variation in spring and winter wheat (Triticum aestivum L.)

    PubMed Central

    2010-01-01

    Background Single nucleotide polymorphisms (SNPs) are ideally suited for the construction of high-resolution genetic maps, studying population evolutionary history and performing genome-wide association mapping experiments. Here, we used a genome-wide set of 1536 SNPs to study linkage disequilibrium (LD) and population structure in a panel of 478 spring and winter wheat cultivars (Triticum aestivum) from 17 populations across the United States and Mexico. Results Most of the wheat oligo pool assay (OPA) SNPs that were polymorphic within the complete set of 478 cultivars were also polymorphic in all subpopulations. Higher levels of genetic differentiation were observed among wheat lines within populations than among populations. A total of nine genetically distinct clusters were identified, suggesting that some of the pre-defined populations shared significant proportion of genetic ancestry. Estimates of population structure (FST) at individual loci showed a high level of heterogeneity across the genome. In addition, seven genomic regions with elevated FST were detected between the spring and winter wheat populations. Some of these regions overlapped with previously mapped flowering time QTL. Across all populations, the highest extent of significant LD was observed in the wheat D-genome, followed by lower LD in the A- and B-genomes. The differences in the extent of LD among populations and genomes were mostly driven by differences in long-range LD ( > 10 cM). Conclusions Genome- and population-specific patterns of genetic differentiation and LD were discovered in the populations of wheat cultivars from different geographic regions. Our study demonstrated that the estimates of population structure between spring and winter wheat lines can identify genomic regions harboring candidate genes involved in the regulation of growth habit. Variation in LD suggests that breeding and selection had a different impact on each wheat genome both within and among populations. The higher extent of LD in the wheat D-genome versus the A- and B-genomes likely reflects the episodes of recent introgression and population bottleneck accompanying the origin of hexaploid wheat. The assessment of LD and population structure in this assembled panel of diverse lines provides critical information for the development of genetic resources for genome-wide association mapping of agronomically important traits in wheat. PMID:21190581

  8. Presence of celiac disease epitopes in modern and old hexaploid wheat varieties: wheat breeding may have contributed to increased prevalence of celiac disease

    PubMed Central

    de Jong, Hein C.; Salentijn, Elma M. J.; Dekking, Liesbeth; Bosch, Dirk; Hamer, Rob J.; Gilissen, Ludovicus J. W. J.; van der Meer, Ingrid M.; Smulders, Marinus J. M.

    2010-01-01

    Gluten proteins from wheat can induce celiac disease (CD) in genetically susceptible individuals. Specific gluten peptides can be presented by antigen presenting cells to gluten-sensitive T-cell lymphocytes leading to CD. During the last decades, a significant increase has been observed in the prevalence of CD. This may partly be attributed to an increase in awareness and to improved diagnostic techniques, but increased wheat and gluten consumption is also considered a major cause. To analyze whether wheat breeding contributed to the increase of the prevalence of CD, we have compared the genetic diversity of gluten proteins for the presence of two CD epitopes (Glia-?9 and Glia-?20) in 36 modern European wheat varieties and in 50 landraces representing the wheat varieties grown up to around a century ago. Glia-?9 is a major (immunodominant) epitope that is recognized by the majority of CD patients. The minor Glia-?20 was included as a technical reference. Overall, the presence of the Glia-?9 epitope was higher in the modern varieties, whereas the presence of the Glia-?20 epitope was lower, as compared to the landraces. This suggests that modern wheat breeding practices may have led to an increased exposure to CD epitopes. On the other hand, some modern varieties and landraces have been identified that have relatively low contents of both epitopes. Such selected lines may serve as a start to breed wheat for the introduction of low CD toxic as a new breeding trait. Large-scale culture and consumption of such varieties would considerably aid in decreasing the prevalence of CD. PMID:20664999

  9. Presence of celiac disease epitopes in modern and old hexaploid wheat varieties: wheat breeding may have contributed to increased prevalence of celiac disease.

    PubMed

    van den Broeck, Hetty C; de Jong, Hein C; Salentijn, Elma M J; Dekking, Liesbeth; Bosch, Dirk; Hamer, Rob J; Gilissen, Ludovicus J W J; van der Meer, Ingrid M; Smulders, Marinus J M

    2010-11-01

    Gluten proteins from wheat can induce celiac disease (CD) in genetically susceptible individuals. Specific gluten peptides can be presented by antigen presenting cells to gluten-sensitive T-cell lymphocytes leading to CD. During the last decades, a significant increase has been observed in the prevalence of CD. This may partly be attributed to an increase in awareness and to improved diagnostic techniques, but increased wheat and gluten consumption is also considered a major cause. To analyze whether wheat breeding contributed to the increase of the prevalence of CD, we have compared the genetic diversity of gluten proteins for the presence of two CD epitopes (Glia-?9 and Glia-?20) in 36 modern European wheat varieties and in 50 landraces representing the wheat varieties grown up to around a century ago. Glia-?9 is a major (immunodominant) epitope that is recognized by the majority of CD patients. The minor Glia-?20 was included as a technical reference. Overall, the presence of the Glia-?9 epitope was higher in the modern varieties, whereas the presence of the Glia-?20 epitope was lower, as compared to the landraces. This suggests that modern wheat breeding practices may have led to an increased exposure to CD epitopes. On the other hand, some modern varieties and landraces have been identified that have relatively low contents of both epitopes. Such selected lines may serve as a start to breed wheat for the introduction of 'low CD toxic' as a new breeding trait. Large-scale culture and consumption of such varieties would considerably aid in decreasing the prevalence of CD. PMID:20664999

  10. Identification of seed dormancy for four populations derived from synthetic hexaploid wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed dormancy is a key adaptive trait for wild species and is also a major domestication-related trait for crop species. Cereal cultivars have been selected for rapid, uniform germination during domestication and breeding and consequently, they generally have an insufficient degree of seed dormancy ...

  11. New insights into the origin of the B genome of hexaploid wheat: Evolutionary relationships at the SPA genomic region with the S genome of the diploid relative Aegilops speltoides

    PubMed Central

    Salse, Jrome; Chagu, Vronique; Bolot, Stphanie; Magdelenat, Ghislaine; Huneau, Ccile; Pont, Caroline; Belcram, Harry; Couloux, Arnaud; Gardais, Soazic; Evrard, Aurlie; Segurens, Batrice; Charles, Mathieu; Ravel, Catherine; Samain, Sylvie; Charmet, Gilles; Boudet, Nathalie; Chalhoub, Boulos

    2008-01-01

    Background Several studies suggested that the diploid ancestor of the B genome of tetraploid and hexaploid wheat species belongs to the Sitopsis section, having Aegilops speltoides (SS, 2n = 14) as the closest identified relative. However molecular relationships based on genomic sequence comparison, including both coding and non-coding DNA, have never been investigated. In an attempt to clarify these relationships, we compared, in this study, sequences of the Storage Protein Activator (SPA) locus region of the S genome of Ae. speltoides (2n = 14) to that of the A, B and D genomes co-resident in the hexaploid wheat species (Triticum aestivum, AABBDD, 2n = 42). Results Four BAC clones, spanning the SPA locus of respectively the A, B, D and S genomes, were isolated and sequenced. Orthologous genomic regions were identified as delimited by shared non-transposable elements and non-coding sequences surrounding the SPA gene and correspond to 35 268, 22 739, 43 397 and 53 919 bp for the A, B, D and S genomes, respectively. Sequence length discrepancies within and outside the SPA orthologous regions are the result of non-shared transposable elements (TE) insertions, all of which inserted after the progenitors of the four genomes divergence. Conclusion On the basis of conserved sequence length as well as identity of the shared non-TE regions and the SPA coding sequence, Ae speltoides appears to be more evolutionary related to the B genome of T. aestivum than the A and D genomes. However, the differential insertions of TEs, none of which are conserved between the two genomes led to the conclusion that the S genome of Ae. speltoides has diverged very early from the progenitor of the B genome which remains to be identified. PMID:19032732

  12. Genetic and Physiological Architecture of Early Vigor in Aegilops tauschii, the D-Genome Donor of Hexaploid Wheat. A Quantitative Trait Loci Analysis1[w

    PubMed Central

    ter Steege, Margreet W.; den Ouden, Franka M.; Lambers, Hans; Stam, Piet; Peeters, Anton J.M.

    2005-01-01

    Plant growth can be studied at different organizational levels, varying from cell, leaf, and shoot to the whole plant. The early growth of seedlings is important for the plant's establishment and its eventual success. Wheat (Triticum aestivum, genome AABBDD) seedlings exhibit a low early growth rate or early vigor. The germplasm of wheat is limited. Wild relatives constitute a source of genetic variation. We explored the physiological and genetic relationships among a range of early vigor traits in Aegilops tauschii, the D-genome donor. A genetic map was constructed with amplified fragment-length polymorphism and simple sequence repeat markers, and quantitative trait loci (QTL) analysis was performed on the F4 population of recombinant inbred lines derived from a cross between contrasting accessions. The genetic map consisted of 10 linkage groups, which were assigned to the seven chromosomes and covered 68% of the D genome. QTL analysis revealed 87 mapped QTLs (log of the odds >2.65) in clusters, 3.1 QTLs per trait, explaining 32% of the phenotypic variance. Chromosomes 1D, 4D, and 7D harbored QTLs for relative growth rate, biomass allocation, specific leaf area, leaf area ratio, and unit leaf rate. Chromosome 2D covered QTLs for rate and duration of leaf elongation, cell production rate, and cell length. Chromosome 5D harbored QTLs for the total leaf mass and area and growth rate of the number of leaves and tillers. The results show that several physiological correlations between growth traits have a genetic basis. Genetic links between traits are not absolute, opening perspectives for identification of favorable alleles in A. tauschii to improve early vigor in wheat. PMID:16183848

  13. Wheat in the Mediterranean revisited tetraploid wheat landraces assessed with elite bread wheat Single Nucleotide Polymorphism markers

    PubMed Central

    2014-01-01

    Background Single Nucleotide Polymorphism (SNP) panels recently developed for the assessment of genetic diversity in wheat are primarily based on elite varieties, mostly those of bread wheat. The usefulness of such SNP panels for studying wheat evolution and domestication has not yet been fully explored and ascertainment bias issues can potentially affect their applicability when studying landraces and tetraploid ancestors of bread wheat. We here evaluate whether population structure and evolutionary history can be assessed in tetraploid landrace wheats using SNP markers previously developed for the analysis of elite cultivars of hexaploid wheat. Results We genotyped more than 100 tetraploid wheat landraces and wild emmer wheat accessions, some of which had previously been screened with SSR markers, for an existing SNP panel and obtained publically available genotypes for the same SNPs for hexaploid wheat varieties and landraces. Results showed that quantification of genetic diversity can be affected by ascertainment bias but that the effects of ascertainment bias can at least partly be alleviated by merging SNPs to haplotypes. Analyses of population structure and genetic differentiation show strong subdivision between the tetraploid wheat subspecies, except for durum and rivet that are not separable. A more detailed population structure of durum landraces could be obtained than with SSR markers. The results also suggest an emmer, rather than durum, ancestry of bread wheat and with gene flow from wild emmer. Conclusions SNP markers developed for elite cultivars show great potential for inferring population structure and can address evolutionary questions in landrace wheat. Issues of marker genome specificity and mapping need, however, to be addressed. Ascertainment bias does not seem to interfere with the ability of a SNP marker system developed for elite bread wheat accessions to detect population structure in other types of wheat. PMID:24885044

  14. Molecular mapping of genes Yr64 and Yr65 for stripe rust resistance in hexaploid derivatives of durum wheat accessions PI 331260 and PI 480016

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important diseases of wheat worldwide and resistance is the best control strategy. Durum wheat accessions PI 331260 and PI 480016 were resistant to all tested Pst races. To transfer the resistance genes to common ...

  15. Mapping and validation of QTL which confer partial resistance to broadly virulent post-2000 North American races of stripe rust in hexaploid wheat

    PubMed Central

    Lowe, Iago; Jankuloski, Ljupcho; Chao, Shiaoman; Chen, Xianming; See, Deven; Dubcovsky, Jorge

    2016-01-01

    A mapping population of 186 recombinant inbred lines developed from a cross between UC1110, an adapted California spring wheat, and PI610750, a synthetic derivative from CIMMYT’s wide-cross program, was evaluated for its response to current California races of stripe rust (Puccinia striiformis f. sp. tritici) in replicated field trials over four seasons (2007–2010) in the northern Sacramento Valley. A genetic map was constructed consisting of 1,493 polymorphic probes (SSRs, DArTs, and ESTs) mapped to 559 unique loci; and QTL analysis revealed the presence of four stripe rust resistance QTL segregating in this population, two from UC1110 (on chromosomes 3BS and 2BS) and two from PI610750 (5AL and 2AS). The two QTL of largest effects (on 3BS and 5AL) were validated in independent populations and their intervals narrowed to 2.5 cM and 4.7 cM, respectively. The 3BS QTL was shown, by allelism test and genotype, to carry a gene different from the Yr30/Sr2 complex. Mapped position also suggests that the 3BS QTL is associated with a gene different from either Yrns-B1 or YrRub, two stripe rust resistance genes mapped to this region in other studies. The 5AL QTL carries a previously unreported partial stripe rust resistance gene, designated here as Yr48. This paper discusses the individual contributions to resistance of these four QTL, their epistatic interactions, and their potential in durable resistance breeding strategies based on combinations of partial resistance genes. PMID:21455722

  16. Re-Evaluation of a Tetraploid Wheat Population Indicates That the Tsn1-ToxA Interaction is the Only Factor Governing Stagonospora Nodorum Blotch Susceptibility

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The wheat Tsn1 gene on chromosome 5B confers sensitivity to the host-selective toxin ToxA produced by the pathogens that cause tan spot and Stagonospora nodorum blotch (SNB). A compatible Tsn1-ToxA interaction is known to play a major role in conferring susceptibility of hexaploid (common) wheat to...

  17. Vernalization treatment induces site-specific DNA hypermethylation at the VERNALIZATION-A1 (VRN-A1) locus in hexaploid winter wheat

    PubMed Central

    2013-01-01

    Background Certain temperate species require prolonged exposure to low temperature to initiate transition from vegetative growth to flowering, a process known as vernalization. In wheat, winter cultivars require vernalization to initiate flowering, making vernalization requirement a trait of key importance in wheat agronomy. The genetic bases of vernalization response have been largely studied in wheat, leading to the characterization of a regulation pathway that involves the key gene VERNALIZATION1 (VRN1). While previous studies in wheat and barley have revealed the functional role of histone modification in setting VRN1 expression, other mechanisms might also be involved. Here, we were interested in determining whether the cold-induced expression of the wheat VRN-A1 gene is associated with a change in DNA methylation. Results We provide the first DNA methylation analysis of the VRN-A1 gene, and describe the existence of methylation at CG but also at non CG sites. While CG sites show a bell-shape profile typical of gene-body methylation, non CG methylation is restricted to the large (8.5kb) intron 1, in a region harboring fragments of transposable elements (TEs). Interestingly, cold induces a site-specific hypermethylation at these non CG sites. This increase in DNA methylation is transmitted through mitosis, and is reset to its original level after sexual reproduction. Conclusions These results demonstrate that VRN-A1 has a particular DNA methylation pattern, exhibiting rapid shift within the life cycle of a winter wheat plant following exposure to particular environmental conditions. The finding that this shift occurs at non CG sites in a TE-rich region opens interesting questions onto the possible consequences of this type of methylation in gene expression. PMID:24330651

  18. Copy number and haplotype variation at the VRN-A1 and central FR-A2 loci are associated with frost tolerance in hexaploid wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Frost tolerance is a key trait to ensure winter wheat survival. Natural variation for this trait is mainly associated with allelic differences at the VERNALIZATION 1 (VRN1) and FROST RESISTANCE 2 (FR2) loci. VRN1 regulates the transition between vegetative and reproductive stages and FR2, a locus in...

  19. A 3,000-loci transcription map of chromosome 3B unravels the structural and functional features of gene islands in hexaploid wheat.

    PubMed

    Rustenholz, Camille; Choulet, Frdric; Laugier, Christel; Safr, Jan; Simkov, Hana; Dolezel, Jaroslav; Magni, Federica; Scalabrin, Simone; Cattonaro, Federica; Vautrin, Sonia; Bellec, Arnaud; Bergs, Hlne; Feuillet, Catherine; Paux, Etienne

    2011-12-01

    To improve our understanding of the organization and regulation of the wheat (Triticum aestivum) gene space, we established a transcription map of a wheat chromosome (3B) by hybridizing a newly developed wheat expression microarray with bacterial artificial chromosome pools from a new version of the 3B physical map as well as with cDNA probes derived from 15 RNA samples. Mapping data for almost 3,000 genes showed that the gene space spans the whole chromosome 3B with a 2-fold increase of gene density toward the telomeres due to an increase in the number of genes in islands. Comparative analyses with rice (Oryza sativa) and Brachypodium distachyon revealed that these gene islands are composed mainly of genes likely originating from interchromosomal gene duplications. Gene Ontology and expression profile analyses for the 3,000 genes located along the chromosome revealed that the gene islands are enriched significantly in genes sharing the same function or expression profile, thereby suggesting that genes in islands acquired shared regulation during evolution. Only a small fraction of these clusters of cofunctional and coexpressed genes was conserved with rice and B. distachyon, indicating a recent origin. Finally, genes with the same expression profiles in remote islands (coregulation islands) were identified suggesting long-distance regulation of gene expression along the chromosomes in wheat. PMID:22034626

  20. A 3,000-Loci Transcription Map of Chromosome 3B Unravels the Structural and Functional Features of Gene Islands in Hexaploid Wheat1[W

    PubMed Central

    Rustenholz, Camille; Choulet, Frdric; Laugier, Christel; af?, Jan; imkov, Hana; Doleel, Jaroslav; Magni, Federica; Scalabrin, Simone; Cattonaro, Federica; Vautrin, Sonia; Bellec, Arnaud; Bergs, Hlne; Feuillet, Catherine; Paux, Etienne

    2011-01-01

    To improve our understanding of the organization and regulation of the wheat (Triticum aestivum) gene space, we established a transcription map of a wheat chromosome (3B) by hybridizing a newly developed wheat expression microarray with bacterial artificial chromosome pools from a new version of the 3B physical map as well as with cDNA probes derived from 15 RNA samples. Mapping data for almost 3,000 genes showed that the gene space spans the whole chromosome 3B with a 2-fold increase of gene density toward the telomeres due to an increase in the number of genes in islands. Comparative analyses with rice (Oryza sativa) and Brachypodium distachyon revealed that these gene islands are composed mainly of genes likely originating from interchromosomal gene duplications. Gene Ontology and expression profile analyses for the 3,000 genes located along the chromosome revealed that the gene islands are enriched significantly in genes sharing the same function or expression profile, thereby suggesting that genes in islands acquired shared regulation during evolution. Only a small fraction of these clusters of cofunctional and coexpressed genes was conserved with rice and B. distachyon, indicating a recent origin. Finally, genes with the same expression profiles in remote islands (coregulation islands) were identified suggesting long-distance regulation of gene expression along the chromosomes in wheat. PMID:22034626

  1. Population Density and Distribution of Wheat Bugs Infesting Durum Wheat in Sardinia, Italy

    PubMed Central

    Salis, Luigi; Goula, Marta; Izquierdo, Jordi; Gordn, Elena

    2013-01-01

    Wheat is a very important crop in Italy, and is infested by wheat bugs belonging to the genera Eurygaster (Hemiptera: Scutellaridae) and Aelia (Hemiptera: Pentatomidae). Many wheat bug infestations have been reported in the north, south, and center of Italy, both in the past as well as recently. The present study was carried out in Sardinia, Italy, during two years (2007 and 2008). The objective of this study was to determine the species and distribution of wheat bugs in durum wheat fields in Sardinia, and to estimate their population density in order to know the incidence of the pest on the island. Sampling took place twice a year (May and June) in three zones, representative of durum wheat cropping in the island. Four species of wheat bugs were found; the predominant species was Eurygaster austriaca (Schrank), followed by Aelia germari (Kuster), Eurygaster maura L., and Aelia acuminata L. The average density of wheat bugs was low (1.1 individuals/m2), but in certain areas it was above the damage threshold (4 individuals/m2). For this reason, the conclusion of the study is that this pest should be monitored in order to control outbreaks and prevent their further spread. PMID:23906035

  2. A Genome-Wide Association Study of Resistance to Stripe Rust (Puccinia striiformis f. sp. tritici) in a Worldwide Collection of Hexaploid Spring Wheat (Triticum aestivum L.)

    PubMed Central

    Maccaferri, Marco; Zhang, Junli; Bulli, Peter; Abate, Zewdie; Chao, Shiaoman; Cantu, Dario; Bossolini, Eligio; Chen, Xianming; Pumphrey, Michael; Dubcovsky, Jorge

    2015-01-01

    New races of Puccinia striiformis f. sp. tritici (Pst), the causal pathogen of wheat stripe rust, show high virulence to previously deployed resistance genes and are responsible for large yield losses worldwide. To identify new sources of resistance we performed a genome-wide association study (GWAS) using a worldwide collection of 1000 spring wheat accessions. Adult plants were evaluated under field conditions in six environments in the western United States, and seedlings were tested with four Pst races. A single-nucleotide polymorphism (SNP) Infinium 9K-assay provided 4585 SNPs suitable for GWAS. High correlations among environments and high heritabilities were observed for stripe rust infection type and severity. Greater levels of Pst resistance were observed in a subpopulation from Southern Asia than in other groups. GWAS identified 97 loci that were significant for at least three environments, including 10 with an experiment-wise adjusted Bonferroni probability < 0.10. These 10 quantitative trait loci (QTL) explained 15% of the phenotypic variation in infection type, a percentage that increased to 45% when all QTL were considered. Three of these 10 QTL were mapped far from previously identified Pst resistance genes and QTL, and likely represent new resistance loci. The other seven QTL mapped close to known resistance genes and allelism tests will be required to test their relationships. In summary, this study provides an integrated view of stripe rust resistance resources in spring wheat and identifies new resistance loci that will be useful to diversify the current set of resistance genes deployed to control this devastating disease. PMID:25609748

  3. A genome-wide association study of resistance to stripe rust (Puccinia striiformis f. sp. tritici) in a worldwide collection of hexaploid spring wheat (Triticum aestivum L.).

    PubMed

    Maccaferri, Marco; Zhang, Junli; Bulli, Peter; Abate, Zewdie; Chao, Shiaoman; Cantu, Dario; Bossolini, Eligio; Chen, Xianming; Pumphrey, Michael; Dubcovsky, Jorge

    2015-03-01

    New races of Puccinia striiformis f. sp. tritici (Pst), the causal pathogen of wheat stripe rust, show high virulence to previously deployed resistance genes and are responsible for large yield losses worldwide. To identify new sources of resistance we performed a genome-wide association study (GWAS) using a worldwide collection of 1000 spring wheat accessions. Adult plants were evaluated under field conditions in six environments in the western United States, and seedlings were tested with four Pst races. A single-nucleotide polymorphism (SNP) Infinium 9K-assay provided 4585 SNPs suitable for GWAS. High correlations among environments and high heritabilities were observed for stripe rust infection type and severity. Greater levels of Pst resistance were observed in a subpopulation from Southern Asia than in other groups. GWAS identified 97 loci that were significant for at least three environments, including 10 with an experiment-wise adjusted Bonferroni probability < 0.10. These 10 quantitative trait loci (QTL) explained 15% of the phenotypic variation in infection type, a percentage that increased to 45% when all QTL were considered. Three of these 10 QTL were mapped far from previously identified Pst resistance genes and QTL, and likely represent new resistance loci. The other seven QTL mapped close to known resistance genes and allelism tests will be required to test their relationships. In summary, this study provides an integrated view of stripe rust resistance resources in spring wheat and identifies new resistance loci that will be useful to diversify the current set of resistance genes deployed to control this devastating disease. PMID:25609748

  4. Application of population sequencing (POPSEQ) for ordering and inputting genotyping-by-sequencing markers in hexaploid wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The advancement of next-generation sequencing technologies in conjunction with new bioinformatics tools enabled fine-tuning of sequence-based high resolution mapping strategies for complex genomes. Although genotyping-by-sequencing (GBS) provides a large number of markers, its application for assoc...

  5. Triticale powdery mildew: population characterization and wheat gene efficiency.

    PubMed

    Bouguennec, Annaig; Trottet, Maxime; du Cheyron, Philippe; Lonnet, Philippe

    2014-01-01

    Powdery mildew has emerged on triticale in the early 2000s in many locations, probably due to a host range expansion of the wheat formae speciales, Blumeria graminis f.sp. tritici. Many triticale cultivars are highly susceptible to powdery mildew, mainly in seedling stage, revealing a probably narrow genetic basis for powdery mildew resistance genes (Pm). Moreover, as Blumeria graminis is an obligate biotrophic fungus, it is very time consuming and difficult to maintain powdery mildew isolates for a non-specialized laboratory and populations can evolve. In order to identify wheat Pm genes efficient against natural populations of powdery mildew, wheat differential hosts and triticale seedlings were inoculated below susceptible triticale crop naturally contaminated by mildew, in several locations and several years. Symptoms on seedlings were measured after approximately two weeks of incubation in favorable fungus growth conditions. According to these data, we classified the Pm genes presents in our wheat differential hosts set in 3 classes: Pm already overcame by triticale powdery mildew, Pm having variable effects and Pm still efficient against triticale mildew. Data on triticale seedlings allowed us to identify some few triticale cultivars resistant to Blumeria graminis in seedling stage. We will try to identify Pm genes present in those cultivars next year by testing them with the characterized isolates of powdery mildew from Gent University. Nevertheless, interspecific crossing of wheat, resistant to powdery mildew in seedling stage, and rye have been initiated to introduce potentially interesting genes for resistance in triticale. PMID:26072579

  6. Genetic basis of triticale breeding (x triticale). IV. Embryo culture for synthesizing primary hexaploid triticales

    SciTech Connect

    Gordei, I.A.; Khodortsova, L.F.

    1986-07-01

    Results are reported on enhancing the efficiency of embryo culture for synthesizing primary hexaploid triticales (AABBRR, 2n = 42). The antioxidant tomatoside has a positive effect on the reduction of progamous incompatibility of wheat with rye and increases the output of wheat-rye amphihaploids. It has been established that irradiation of embryos, cultured on nutrient medium, with helium-neon laser, increases significantly (P < 0.01) the regeneration frequency of the wheat-rye hybrid embryos. The highest frequency (40%) of amphidiploids was obtained by treating the plants with 0.15% colchicine through roots during the tillering phase. Hexaploid triticales from 11 cross combinations between tetraploid wheats (AABB, 2n = 28) and diploid rye (RR, 2n = 14) formed the initial material for breeding.

  7. Genetic mapping of race-specific stem rust resistance in the synthetic hexaploid W7984 x Opata M85 mapping population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stem rust (caused by Puccinia graminis f. sp. tritici) has historically caused severe yield losses of wheat (Triticum aestivum) worldwide and has been one of the most feared diseases of wheat and barley (Hordeum vulgare). Stem rust has been controlled successfully through the use of resistant varie...

  8. Change in biotypic diversity of Russian wheat aphid (Hemiptera: Aphididae) populations in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A key component of Russian wheat aphid (RWA), Diuraphis noxia (Kurdjumov), management has been through planting resistant wheat cultivars. A new biotype, RWA2, appeared in 2003 which caused widespread damage to wheat cultivars containing Dn4 gene. Biotypic diversity in RWA populations has not been...

  9. Cytotype distribution at a diploidhexaploid contact zone in Aster amellus (Asteraceae)

    PubMed Central

    Castro, S.; Loureiro, J.; Prochzka, T.; Mnzbergov, Z.

    2012-01-01

    Background and Aims The present study aims to assess the diversity and distribution of cytotypes of Aster amellus in central and eastern Europe, contributing with data to improve understanding of the evolutionary dynamics of the contact zone between diploids and hexaploids of this polyploid complex. Methods Large-scale cytotype screening of 4720 individuals collected in 229 populations was performed using 4?,6-diamidino-2-phenylindole (DAPI) flow cytometry. Fine-scale cytotype screening was performed in the mixed-ploidy population. Reproductive variables, such as number of florets per flower head, seed set and seedling emergence, as well as ploidy level of seeds and seedlings were recorded in this population. Key Results The diploidhexaploid contact zone is large and complex, reaching the Czech Republic in the west, Austria in the south, Poland in the north-east and Romania in the extreme east of the surveyed areas. Most populations presented only one cytotype, either diploid or hexaploid. In several areas of the contact zone both cytotypes were found to grow in parapatry. One mixed-ploidy population of diploids and hexaploids was detected for the first time, but no signs of hybridization were detected. In this population, diploids had a significantly lower reproductive success, and significantly higher production of intercytotype offspring, being in reproductive disadvantage in comparison with hexaploids. Conclusions The contact zone of diploid and hexaploid A. amellus in central and eastern Europe seems to be highly dynamic and diffuse, with both primary and secondary contacts being possible. The obtained results suggest the origin of hexaploids through diploids, overall supporting previous hypotheses that this species is autopolyploid. Data from the only mixed-ploidy population detected so far suggest that the minority cytotype exclusion is an important evolutionary mechanisms driving the prevalence of single-cytotype populations, and thus contributing to the current distributional patterns of the cytotypes of A. amellus. PMID:22887024

  10. Virulence structure of the eastern U.S. wheat powdery mildew population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known about the population structure of wheat powdery mildew in the eastern 2 U.S., and the most recent report on virulence in this pathogen population involved isolates 3 collected in 1993-94. In the present study, wheat leaves naturally infected with powdery mildew 4 were collected from ...

  11. Mapping QTL for Soft Wheat Quality in Multiple Populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soft wheat is used to make a wide variety of products and thus variation for quality parameters is important to breed soft wheat cultivars suitable for different uses. Breeders need more knowledge about the genetics of soft wheat quality and systems for marker-assisted selection (MAS). MAS is best...

  12. Genetic Diversity, Population Structure and Linkage Disequilibrium in U.S. Elite Winter Wheat (Triticum Aestivum L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Information on genetic diversity and population structure of elite wheat breeding lines promotes effective use of genetic resources. We analyzed 205 elite wheat breeding lines from major winter wheat breeding programs in the U.S.A. using 245 markers across the wheat genomes. This collection showed a...

  13. Change in Biotypic Diversity of Russian Wheat Aphid (Hemiptera: Aphididae) Populations in the United States.

    PubMed

    Puterka, G J; Giles, K L; Brown, M J; Nicholson, S J; Hammon, R W; Peairs, F B; Randolph, T L; Michaels, G J; Bynum, E D; Springer, T L; Armstrong, J S; Mornhinweg, D W

    2015-04-01

    A key component of Russian wheat aphid, Diuraphis noxia (Kurdjumov), management has been through planting resistant wheat cultivars. A new biotype, RWA2, appeared in 2003 which caused widespread damage to wheat cultivars containing the Dn4 gene. Biotypic diversity in Russian wheat aphid populations has not been addressed since 2005 when RWA2 dominated the biotype complex. Our objectives were to determine the biotypic diversity in the Central Great Plains and Colorado Plateau at regional (2010, 2011, 2013) and local (2012) levels and detect the presence of new Russian wheat aphid biotypes. Regional and within-field aphid collections were screened against Russian wheat aphid-resistant wheat genotypes containing genes Dn3, Dn4, Dn6, Dn7, Dn9, CI2401; and resistant barley STARS 9301B. In 2010, all aphid collections from Texas were avirulent to the Dn4 resistance gene in wheat. Regional results revealed Dn4 avirulent RWA6 was widespread (55-84%) in populations infesting wheat in both regions. Biotypes RWA1, 2, and 3/7 were equally represented with percentages<20% each while RWA8 was rarely detected. Combining percentages of RWA1, 6, and 8 across regions to estimate avirulence to Dn4 gene revealed high percentages for both 2011 (64-80%) and 2013 (69-90%). In contrast, the biotype structure at the local level differed where biotype percentages varied up to ?2-fold between fields. No new biotypes were detected; therefore, Dn7, CI2401, and STARS9301B remained resistant to all known Russian wheat aphid biotypes. This study documents a shift to Dn4 avirulent biotypes and serves as a valuable baseline for biotypic diversity in Russian wheat aphid populations prior to the deployment of new Russian wheat aphid-resistant wheat cultivars. PMID:26470192

  14. Exceptionally High Levels of Genetic Diversity in Wheat Curl Mite (Acari: Eriophyidae) Populations from Turkey.

    PubMed

    Szyd?o, W; Hein, G; Denizhan, E; Skoracka, A

    2015-08-01

    Recent research on the wheat curl mite species complex has revealed extensive genetic diversity that has distinguished several genetic lineages infesting bread wheat (Triticum aestivum L.) and other cereals worldwide. Turkey is the historical region of wheat and barley (Hordeum vulgare L.) domestication and diversification. The close relationship between these grasses and the wheat curl mite provoked the question of the genetic diversity of the wheat curl mite in this region. The scope of the study was to investigate genetic differentiation within the wheat curl mite species complex on grasses in Turkey. Twenty-one wheat curl mite populations from 16 grass species from nine genera (Agropyron sp., Aegilops sp., Bromus sp., Elymus sp., Eremopyrum sp., Hordeum sp., Poa sp., Secale sp., and Triticum sp.) were sampled in eastern and southeastern Turkey for genetic analyses. Two molecular markers were amplified: the cytochrome oxidase subunit I coding region of mtDNA (COI) and the D2 region of 28S rDNA. Phylogenetic analyses revealed high genetic variation of the wheat curl mite in Turkey, primarily on Bromus and Hordeum spp., and exceptionally high diversity of populations associated with bread wheat. Three wheat-infesting wheat curl mite lineages known to occur on other continents of the world, including North and South America, Australia and Europe, were found in Turkey, and at least two new genetic lineages were discovered. These regions of Turkey exhibit rich wheat curl mite diversity on native grass species. The possible implications for further studies on the wheat curl mite are discussed. PMID:26470350

  15. Fertility of a spontaneous hexaploid male Siberian sturgeon, Acipenser baerii

    PubMed Central

    2014-01-01

    Background Evolution of sturgeons and paddlefishes (order Acipenseriformes) is inherently connected with polyploidization events which resulted in differentiation of ploidy levels and chromosome numbers of present acipenseriform species. Moreover, allopolyploidization as well as autopolyploidization seems to be an ongoing process in these fishes and individuals with abnormal ploidy levels were occasionally observed within sturgeon populations. Here, we reported occurrence of Siberian sturgeon (Acipenser baerii) male with abnormal ploidy level for this species, accessed its ploidy level and chromosome number and investigate its potential sterility or fertility in comparison with normal individuals of sterlet (A. ruthenus), Russian sturgeon (A. gueldenstaedtii) and Siberian sturgeon (A. baerii). Results Acipenser ruthenus possessed 120 chromosomes, exhibiting recent diploidy (2n), A. gueldenstaedtii and A. baerii had ~245 chromosomes representing recent tetraploidy (4n), and A. baerii male with abnormal ploidy level had ~ 368 chromosomes, indicating recent hexaploidy (6n). Genealogy assessed from the mtDNA control region did not reveal genome markers of other sturgeon species and this individual was supposed to originate from spontaneous 1.5 fold increment in number of chromosome sets with respect to the number most frequently found in nature for this species. Following hormone stimulation, the spontaneous hexaploid male produced normal sperm with ability for fertilization. Fertilization of A. baerii and A. gueldenstaedtii ova from normal 4n level females with sperm of the hexaploid male produced viable, non-malformed pentaploid (5n) progeny with a ploidy level intermediate to those of the parents. Conclusion This study firstly described occurrence of hexaploid individual of A. baerii and confirmed its autopolyploid origin. In addition to that, the first detailed evidence about fertility of spontaneous hexaploid sturgeon was provided. If 1.5 fold increment in number of chromosome sets occurring in diploids, resulted triploids possess odd number of chromosome sets causing their sterility or subfertility due to interference of gametogenesis. In contrast, 1.5 fold increment in number of chromosome sets in naturally tetraploid A. baerii resulted in even number of chromosome sets and therefore in fertility of the hexaploid specimen under study. PMID:24410899

  16. Biotypic diversity in Colorado Russian wheat aphid (Hemiptera: Aphididae) populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The biotypic diversity of the Russian wheat aphid, Diuraphis noxia (Kurdjumov), was assessed in five isolates collected in Colorado. Three isolates, RWA 1, RWA 2, and an isolate from Montezuma County, CO designated RWA6, were originally collected from cultivated wheat, Triticum aestivum L. The fou...

  17. Large deletions in the CBF gene cluster at the Fr-B2 locus are associated with reduced frost tolerance in wheat

    PubMed Central

    Pearce, Stephen; Zhu, Jie; Boldizsár, Ákos; Vágújfalvi, Attila; Burke, Adrienne; Garland-Campbell, Kimberley; Galiba, Gábor; Dubcovsky, Jorge

    2016-01-01

    Wheat plants which are exposed to periods of low temperatures (cold acclimation) exhibit increased survival rates when they are subsequently exposed to freezing temperatures. This process is associated with large-scale changes in the transcriptome which are modulated by a set of tandemly duplicated CBF (C-repeat Binding Factor) transcription factors located at the Fr-2 (Frost Resistance-2) locus. While Arabidopsis has three tandemly duplicated CBF genes, the CBF family in wheat has undergone an expansion and at least 15 CBF genes have been identified, eleven of which are present at the Fr-2 loci on homoeologous group 5 chromosomes. We report here the discovery of three large deletions which eliminate six, nine, and all eleven CBF genes from the Fr-B2 locus in tetraploid and hexaploid wheat. In wild emmer wheat, the Fr-B2 deletions were found only among the accessions from the southern sub-populations. Among cultivated wheats, the Fr-B2 deletions were more common among varieties with a spring growth habit than among those with a winter growth habit. Replicated freezing tolerance experiments showed that both the deletion of nine CBF genes in tetraploid wheat and the complete Fr-B2 deletion in hexaploid wheat are associated with significant reductions in survival after exposure to freezing temperatures. Our results suggest that selection for the wild type Fr-B2 allele may be beneficial for breeders selecting for varieties with improved frost tolerance. PMID:23884601

  18. Domestication quantitative trait loci in Triticum dicoccoides, the progenitor of wheat

    PubMed Central

    Peng, Junhua; Ronin, Yefim; Fahima, Tzion; Rder, Marion S.; Li, Youchun; Nevo, Eviatar; Korol, Abraham

    2003-01-01

    Wild emmer wheat, Triticum dicoccoides, is the progenitor of modern tetraploid and hexaploid cultivated wheats. Our objective was to map domestication-related quantitative trait loci (QTL) in T. dicoccoides. The studied traits include brittle rachis, heading date, plant height, grain size, yield, and yield components. Our mapping population was derived from a cross between T. dicoccoides and Triticum durum. Approximately 70 domestication QTL effects were detected, nonrandomly distributed among and along chromosomes. Seven domestication syndrome factors were proposed, each affecting 511 traits. We showed: (i) clustering and strong effects of some QTLs; (ii) remarkable genomic association of strong domestication-related QTLs with gene-rich regions; and (iii) unexpected predominance of QTL effects in the A genome. The A genome of wheat may have played a more important role than the B genome during domestication evolution. The cryptic beneficial alleles at specific QTLs derived from T. dicoccoides may contribute to wheat and cereal improvement. PMID:12604784

  19. Irrigation Differentially Impacts Populations of Indigenous Antibiotic-Producing Pseudomonas spp. in the Rhizosphere of Wheat

    PubMed Central

    Mavrodi, Olga V.; Mavrodi, Dmitri V.; Parejko, James A.; Thomashow, Linda S.

    2012-01-01

    This work determined the impact of irrigation on the seasonal dynamics of populations of Pseudomonas spp. producing the antibiotics phenazine-1-carboxylic acid (Phz+) and 2,4-diacetylphloroglucinol (Phl+) in the rhizosphere of wheat grown in the low-precipitation zone (150 to 300 mm annually) of the Columbia Plateau of the Inland Pacific Northwest. Population sizes and plant colonization frequencies of Phz+ and Phl+ Pseudomonas spp. were determined in winter and spring wheat collected during the growing seasons from 2008 to 2009 from selected commercial dryland and irrigated fields in central Washington State. Only Phz+ bacteria were detected on dryland winter wheat, with populations ranging from 4.8 to 6.3 log CFU g?1 of root and rhizosphere colonization frequencies of 67 to 100%. The ranges of population densities of Phl+ and Phz+ Pseudomonas spp. recovered from wheat grown under irrigation were similar, but 58 to 100% of root systems were colonized by Phl+ bacteria whereas only 8 to 50% of plants harbored Phz+ bacteria. In addition, Phz+ Pseudomonas spp. were abundant in the rhizosphere of native plant species growing in nonirrigated areas adjacent to the sampled dryland wheat fields. This is the first report that documents the impact of irrigation on indigenous populations of two closely related groups of antibiotic-producing pseudomonads that coinhabit the rhizosphere of an economically important cereal crop. These results demonstrate how crop management practices can influence indigenous populations of antibiotic-producing pseudomonads with the capacity to suppress soilborne diseases of wheat. PMID:22389379

  20. Chapter 6: Floral Transformation of Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hexaploid wheat is one of the worlds most important staple crops but genetic transformation is still challenging. We are developing a floral transformation protocol for wheat that does not require tissue culture. Several T-DNA transformants have been produced in the high quality, hard red germpla...

  1. EMS-treated hexaploid wheat genotype Scarlet has enhanced tolerance to the soilborne necrotrophic pathogens Rhizoctonia solani AG-8 and R. oryzae. 2009. Theor. Appl. Genet. 119(February): 293-303

    Technology Transfer Automated Retrieval System (TEKTRAN)

    R. solani AG-8 and R. oryzae cause Rhizoctonia root rot and pre-emergence damping-off, yield-limiting diseases that pose a barrier to the adoption of reduced tillage wheat production systems intended to reduce soil erosion. We report the first genetic resistance to necrotrophic root pathogens Rhizo...

  2. Genomic in situ hybridization (GISH) analysis of the North and Central American hexaploid wild potato species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    About 70% of the approximately 100 wild potato (Solanum L. section Petota Dumort.) species are diploid (2n = 2x = 24), with the rest tetraploid (2n = 4x = 48), hexaploid (2n = 6x = 72), and a few rare triploid and pentaploid populations. Determination of the type of polyploidy and the development of...

  3. Population divergence in the wheat leaf rust fungus Puccinia triticina is correlated with wheat evolution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to determine if the evolutionary history of the obligate pathogen on wheat, Puccinia triticina, is correlated with adaptation to hosts with different ploidy levels. Sequence data from 15 loci with different levels of polymorphism were generated. Phylogenetic analyses ...

  4. Registration of the MN98550/MN99394 Wheat Recombinant Inbred Mapping Population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A mapping population was developed from the two hard red spring wheat (Triticum aestivum L.) breeding lines MN98550 and MN99394 at the University of Minnesota. This population has 139 F6:8 recombinant inbred lines (RILs) and was assigned the USDA-ARS Germplasm Resources Information Network (GRIN) ac...

  5. IMPACT OF IRRIGATION ON POPULATIONS OF ANTIBIOTIC-PRODUCING PSEUDOMONAS SPP. IN RHIZOSPHERE OF WHEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This work studied the impact of irrigation on seasonal dynamics of populations of phenazine (Phz+) and 2,4-diacetylphloroglucinol (Phl+) Pseudomonas spp. in the rhizosphere of wheat grown in the low-precipitation zone (<400 mm) of the Columbia Plateau of the Inland Pacific Northwest, WA. Population...

  6. Mapping stripe rust resistance genes in a Brundage x Coda winter wheat recombinant inbred line population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A recombinant inbred line (RIL) mapping population developed from a cross between winter wheat (Triticum aestivum L.) cultivars Coda and Brundage was evaluated for reaction to stripe rust (caused by Puccinia striiformis f. sp. tritici). Two hundred and sixty eight RIL from the population were evalua...

  7. [Monitoring winter wheat population dynamics using an active crop sensor].

    PubMed

    Wu, Jun-Hua; Yue, Shan-Chao; Hou, Peng; Meng, Qing-Feng; Cui, Zhen-Ling; Li, Fei; Chen, Xin-Ping

    2011-02-01

    Tiller density plays an important role in attaining optimum grain yield and applying topdressing N in winter wheat. However, the traditional approach based on determining tiller density is time-consuming and labor-intensive. As technology advances, remote sensing might provide an opportunity in eliminating this7 problem. In the present paper, an N rate experiment and a variety-seeding and sowing dates experiment were conducted in Quzhou County, Hebei Province in 2008/2009 to develop the models to predict the amount of winter wheat tillers. Positive linear relationships between vegetation indices and tillers were observed across growth stages (R2, 0.25-0.64 for NDVI; 0.26-0.65 for RVI). The validation results indicated that the prediction using NDVI had the higher coefficient of determination (R2, 0.54-0.64), the lower root mean square error (RMSE, 260-350 tillers m(-2)) and relative error (RE, 16.3%-23.0%) at early growth stages of winter wheat. We conclude that active GreenSeeker sensor is a promising tool for timely monitoring of winter wheat tiller density. PMID:21510421

  8. A SNP genotyping array for hexaploid oat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recognizing a need in cultivated hexaploid oat (Avena sativa L.) for a reliable set of reference SNPs, we have developed a 6K BeadChip design containing 257 Infinium I and 5,486 Infinium II designs corresponding to 5,743 SNPs. Of those, 4,975 SNPs yielded successful assays after array manufacturing...

  9. Identification of genome-specific transcripts in wheat-rye translocation lines.

    PubMed

    Lee, Tong Geon; Seo, Yong Weon

    2015-09-01

    Studying gene expression in wheat-rye translocation lines is complicated due to the presence of homeologs in hexaploid wheat and high levels of synteny between wheat and rye genomes (Naranjo and Fernandez-Rueda, 1991 [1]; Devos et al., 1995 [2]; Lee et al., 2010 [3]; Lee et al., 2013 [4]). To overcome limitations of current gene expression studies on wheat-rye translocation lines and identify genome-specific transcripts, we developed a custom Roche NimbleGen Gene Expression microarray that contains probes derived from the sequence of hexaploid wheat, diploid rye and diploid progenitors of hexaploid wheat genome (Lee et al., 2014). Using the array developed, we identified genome-specific transcripts in a wheat-rye translocation line (Lee et al., 2014). Expression data are deposited in the NCBI Gene Expression Omnibus (GEO) under accession number GSE58678. Here we report the details of the methods used in the array workflow and data analysis. PMID:26484243

  10. Identification of genome-specific transcripts in wheatrye translocation lines

    PubMed Central

    Lee, Tong Geon; Seo, Yong Weon

    2015-01-01

    Studying gene expression in wheatrye translocation lines is complicated due to the presence of homeologs in hexaploid wheat and high levels of synteny between wheat and rye genomes (Naranjo and Fernandez-Rueda, 1991 [1]; Devos et al., 1995 [2]; Lee et al., 2010 [3]; Lee et al., 2013 [4]). To overcome limitations of current gene expression studies on wheatrye translocation lines and identify genome-specific transcripts, we developed a custom Roche NimbleGen Gene Expression microarray that contains probes derived from the sequence of hexaploid wheat, diploid rye and diploid progenitors of hexaploid wheat genome (Lee et al., 2014). Using the array developed, we identified genome-specific transcripts in a wheatrye translocation line (Lee et al., 2014). Expression data are deposited in the NCBI Gene Expression Omnibus (GEO) under accession number GSE58678. Here we report the details of the methods used in the array workflow and data analysis. PMID:26484243

  11. Ecogeography, genetic diversity, and breeding value of wild emmer wheat (Triticum dicoccoides Korn ex Asch. & Graebn.) Thell.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wild emmer wheat (Triticum dicoccoides Körn ex Asch. & Graebn.) Thell. is the allotetraploid (2n=4x=28; genome BBAA) progenitor of cultivated wheat. It is fully compatible with the tetraploid (BBAA) durum wheat (Triticum durum), and can be crossed with the hexaploid (2n=6x=42; BBAADD) wheat (Triticu...

  12. ESTIMATING OF EFFECTIVE POPULATION SIZES OF LABORATORY AND FIELD SAMPLES OF WHEAT STREAK MOSAIC VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We previously have used two different approaches, each essentially measuring the rate of genetic drift, to arrive at estimates effective population size (Ne) of wheat streak mosaic virus (WSMV) that are remarkably low. Fixation rates in plants infected with two strains of WSMV yielded Ne = 4 for sy...

  13. Irrigation differentially impacts populations of indigenous antibiotic-producing Pseudomonas spp. in the rhizosphere of wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This work determined the impact of irrigation on the seasonal dynamics of populations of Pseudomonas spp. producing the antibiotics phenazine-1-carboxylic acid (Phz+) and 2,4-diacetylphloroglucinol (Phl+) in the rhizosphere of wheat grown in the low precipitation zone (150 to 300 mm annually) of the...

  14. QTLS FOR FUSARIUM HEAD BLIGHT RESPONSE IN A WHEAT DH POPULATION OF WANGSHUIBAI/ ALONDRA'S'

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A doubled haploid (DH) wheat population derived from the cross Wangshuibai/Alondra’s’ was developed through chromosome doubling of haploids generated by anther culture of hybrids. Fusarium head blight (FHB) was evaluated for three years from 2001 to 2003 in Jianyang, Fujian Province, China, where ep...

  15. Registration of USG 3209/Jaypee Wheat Recombinant Inbred Line Mapping Population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘USG 3209’/‘Jaypee’ (Reg. No. MP-3, NSL 465777 MAP), is a soft red winter wheat (Triticum aestivum L.) recombinant inbred line (RIL) population developed by Virginia Polytechnic Institute and State University and submitted to the USDA–ARS National Small Grains Germplasm Research Facility in Aberdeen...

  16. Selecting and Sorting Waxy Wheat Kernels Using Near-Infrared Spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An automated single kernel near-infrared (NIR) sorting system was used to separate single wheat (Triticum aestivum L.) kernels with amylose-free (waxy) starch from reduced-amylose (partial waxy) or wild-type wheat kernels. Waxy kernels of hexaploid wheat are null for the granule-bound starch syntha...

  17. De Novo Transcriptome Assembly and Analyses of Gene Expression during Photomorphogenesis in Diploid Wheat Triticum monococcum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Triticum monococcum (2n), a close ancestor of the A-genome progenitor of cultivated hexaploid wheat, was used as a model to study components regulating photomorphogenesis in diploid wheat. Constructed were genome-wide transcriptomes of two Triticum monococcum subspecies, the wild winter wheat T. mo...

  18. Progress toward breeding of waxy (amylose-free) wheats for the Great Plains of North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In hexaploid wheats, three independent loci (Wx-A1, Wx-B1 and Wx-D1) encode production of the granule-bound starch synthase (GBSS) also known as the “waxy” protein. Waxy, or amylose-free wheats, have been developed via combination of null mutations at all three loci (Nakamura et al., 1995). Wheat ...

  19. Evaluation of seedling resistance to tan spot and Stagonospora nodorum blotch in tetraploid wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tetraploid durum wheat (Triticum turgidum L. ssp. durum, 2n = 4x = 28, AABB) is an important cereal specifically used for making pasta products but its production is more vulnerable to various wheat diseases than hexaploid bread wheat (T. aestivum L., 2n = 6x = 42, AABBDD). In order to identify res...

  20. Utilization of deletion bins to anchor and order sequences along the wheat 7B chromosome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bread wheat (Triticum aestivum L.) has a large, complex and highly repetitive genome which is challenging to assemble into high quality pseudo-chromosomes. As part of the international effort to sequence the hexaploid bread wheat genome by the international wheat genome sequencing consortium (IWGSC)...

  1. Registration of Hessian fly resistant wheat germplasm line P921696

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new gene for resistance to biotype L of the Hessian fly, Mayetiola destructor (Say), was transferred from an accession of tetraploid durum wheat (CI3984), Triticum turgidum Desf., into hexaploid common wheat, T. aestivum L. Through backcrossing twice to the cultivar 'Newton' (CI17715), twice to '...

  2. Genetic Structure of Mycosphaerella Graminicola Populations in the Major Wheat-Growing Regions of the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Septoria tritici blotch (STB), caused by Mycosphaerella graminicola, is one of the major diseases of wheat worldwide. However, there is little information available on the population genetic structure of this pathogen in the major wheat-growing regions of the United States. We analyzed the genetic s...

  3. Absence of gene flow between diploids and hexaploids of Aster amellus at multiple spatial scales.

    PubMed

    Mnzbergov, Z; Surinov, M; Castro, S

    2013-02-01

    The potential for gene exchange across ploidy levels has long been recognized, but only a few studies have explored the rate of gene flow among different cytotypes. In addition, most of the existing knowledge comes from contact zones between diploids and tetraploids. The purpose of this paper was to investigate relationships between diploid and hexaploid individuals within the Aster amellus aggregate. A. amellus is known to occur in diploid and hexaploid cytotypes in Europe, with a complex contact zone in central Europe. Patterns of genetic diversity were investigated using seven microsatellite loci at three different spatial scales: (1) in the single known mixed-ploidy population; (2) in populations at the contact zone and (3) in a wider range of populations across Europe. The results show clear separation of the cytotypes at all three spatial scales. In addition, analysis of molecular variance strongly supported a model predicting a single origin of the hexaploids, with no or very limited gene flow between the cytotypes. Some hexaploid individuals found in the mixed-ploidy population, however, fell into the diploid cluster. This could suggest recurrent polyploid formation or occasional cross-pollination between cytotypes; however, there are strong post-zygotic breeding barriers between the two cytotypes, making the latter less plausible. Overall, the results suggest that the cytotypes could represent two cryptic species. Nevertheless, their formal separation is difficult as they cannot be distinguished morphologically, occupy very similar habitat conditions and have largely overlapping distribution ranges. These results show that polyploid complexes must be treated with caution as they can hide biological diversity and can have different adaptation potentials, evolving independently. PMID:23169557

  4. Population genetic analysis and trichothecene profiling of Fusarium graminearum from wheat in Uruguay.

    PubMed

    Pan, D; Mionetto, A; Calero, N; Reynoso, M M; Torres, A; Bettucci, L

    2016-01-01

    Fusarium graminearum sensu stricto (F. graminearum s.s.) is the major causal agent of Fusarium head blight of wheat worldwide, and contaminates grains with trichothecene mycotoxins that cause serious threats to food safety and animal health. An important aspect of managing this pathogen and reducing mycotoxin contamination of wheat is knowledge regarding its population genetics. Therefore, isolates of F. graminearum s.s. from the major wheat-growing region of Uruguay were analyzed by amplified fragment length polymorphism assays, PCR genotyping, and chemical analysis of trichothecene production. Of the 102 isolates identified as having the 15-ADON genotype via PCR genotyping, all were DON producers, but only 41 strains were also 15-ADON producers, as determined by chemical analysis. The populations were genotypically diverse but genetically similar, with significant genetic exchange occurring between them. Analysis of molecular variance indicated that most of the genetic variability resulted from differences between isolates within populations. Multilocus linkage disequilibrium analysis suggested that the isolates had a panmictic population genetic structure and that there is significant recombination occurs in F. graminearum s.s. In conclusion, tour findings provide the first detailed description of the genetic structure and trichothecene production of populations of F. graminearum s.s. from Uruguay, and expands our understanding of the agroecology of F. graminearum and of the correlation between genotypes and trichothecene chemotypes. PMID:26985955

  5. Diversification of the celiac disease ?-gliadin complex in wheat: a 33-mer peptide with six overlapping epitopes, evolved following polyploidization.

    PubMed

    Ozuna, Carmen V; Iehisa, Julio C M; Gimnez, Mara J; Alvarez, Juan B; Sousa, Carolina; Barro, Francisco

    2015-06-01

    The gluten proteins from wheat, barley and rye are responsible both for celiac disease (CD) and for non-celiac gluten sensitivity, two pathologies affecting up to 6-8% of the human population worldwide. The wheat ?-gliadin proteins contain three major CD immunogenic peptides: p31-43, which induces the innate immune response; the 33-mer, formed by six overlapping copies of three highly stimulatory epitopes; and an additional DQ2.5-glia-?3 epitope which partially overlaps with the 33-mer. Next-generation sequencing (NGS) and Sanger sequencing of ?-gliadin genes from diploid and polyploid wheat provided six types of ?-gliadins (named 1-6) with strong differences in their frequencies in diploid and polyploid wheat, and in the presence and abundance of these CD immunogenic peptides. Immunogenic variants of the p31-43 peptide were found in most of the ?-gliadins. Variants of the DQ2.5-glia-?3 epitope were associated with specific types of ?-gliadins. Remarkably, only type 1 ?-gliadins contained 33-mer epitopes. Moreover, the full immunodominant 33-mer fragment was only present in hexaploid wheat at low abundance, probably as the result of allohexaploidization events from subtype 1.2 ?-gliadins found only in Aegilops tauschii, the D-genome donor of hexaploid wheat. Type 3 ?-gliadins seem to be the ancestral type as they are found in most of the ?-gliadin-expressing Triticeae species. These findings are important for reducing the incidence of CD by the breeding/selection of wheat varieties with low stimulatory capacity of T cells. Moreover, advanced genome-editing techniques (TALENs, CRISPR) will be easier to implement on the small group of ?-gliadins containing only immunogenic peptides. PMID:25864460

  6. Analysis of TaALMT1 traces the transmission of aluminum resistance in cultivated common wheat (Triticum aestivum L.).

    PubMed

    Raman, Harsh; Ryan, Peter R; Raman, Rosy; Stodart, Benjamin J; Zhang, Kerong; Martin, Peter; Wood, Rachel; Sasaki, Takayuki; Yamamoto, Yoko; Mackay, Michael; Hebb, Diane M; Delhaize, Emmanuel

    2008-02-01

    Allele diversities of four markers specific to intron three, exon four and promoter regions of the aluminum (Al) resistance gene of wheat (Triticum aestivum L.) TaALMT1 were compared in 179 common wheat cultivars used in international wheat breeding programs. In wheat cultivars released during the last 93 years, six different promoter types were identified on the basis of allele size. A previous study showed that Al resistance was not associated with a particular coding allele for TaALMT1 but was correlated with blocks of repeated sequence upstream of the coding sequence. We verified the linkage between these promoter alleles and Al resistance in three doubled haploid and one intercross populations segregating for Al resistance. Molecular and pedigree analysis suggest that Al resistance in modern wheat germplasm is derived from several independent sources. Analysis of a population of 278 landraces and subspecies of wheat showed that most of the promoter alleles associated with Al resistance pre-existed in Europe, the Middle East and Asia prior to dispersal of cultivated germplasm around the world. Furthermore, several new promoter alleles were identified among the landraces surveyed. The TaALMT1 promoter alleles found within the spelt wheats were consistent with the hypothesis that these spelts arose on several independent occasions from hybridisations between non-free-threshing tetraploid wheats and Al-resistant hexaploid bread wheats. The strong correlation between Al resistance and Al-stimulated malate efflux from the root apices of 49 diverse wheat genotypes examined was consistent with the previous finding that Al resistance in wheat is conditioned primarily by malate efflux. These results demonstrate that the markers based on intron, exon and promoter regions of TaALMT1 can trace the inheritance of the Al resistance locus within wheat pedigrees and track Al resistance in breeding programmes. PMID:18046532

  7. Population Genetic Analysis of an Eastern U.S. Wheat Powdery Mildew Population Reveals Geographic and Recent Common Ancestry with U.K. and Israeli Populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The structure of the U.S. wheat powdery mildew population (Blumeria graminis f. sp. tritici) has not been investigated, and the global evolutionary history of B. g. tritici is largely unknown. After gathering 141 single-ascoporic B. g. tritici isolates from 10 eastern U.S. locations, 34 isolates fr...

  8. Efficiently tracking selection in a multiparental population: the case of earliness in wheat.

    PubMed

    Thpot, Stphanie; Restoux, Gwendal; Goldringer, Isabelle; Hospital, Frdric; Gouache, David; Mackay, Ian; Enjalbert, Jrme

    2015-02-01

    Multiparental populations are innovative tools for fine mapping large numbers of loci. Here we explored the application of a wheat Multiparent Advanced Generation Inter-Cross (MAGIC) population for QTL mapping. This population was created by 12 generations of free recombination among 60 founder lines, following modification of the mating system from strict selfing to strict outcrossing using the ms1b nuclear male sterility gene. Available parents and a subset of 380 SSD lines of the resulting MAGIC population were phenotyped for earliness and genotyped with the 9K i-Select SNP array and additional markers in candidate genes controlling heading date. We demonstrated that 12 generations of strict outcrossing rapidly and drastically reduced linkage disequilibrium to very low levels even at short map distances and also greatly reduced the population structure exhibited among the parents. We developed a Bayesian method, based on allelic frequency, to estimate the contribution of each parent in the evolved population. To detect loci under selection and estimate selective pressure, we also developed a new method comparing shifts in allelic frequency between the initial and the evolved populations due to both selection and genetic drift with expectations under drift only. This evolutionary approach allowed us to identify 26 genomic areas under selection. Using association tests between flowering time and polymorphisms, 6 of these genomic areas appeared to carry flowering time QTL, 1 of which corresponds to Ppd-D1, a major gene involved in the photoperiod sensitivity. Frequency shifts at 4 of 6 areas were consistent with earlier flowering of the evolved population relative to the initial population. The use of this new outcrossing wheat population, mixing numerous initial parental lines through multiple generations of panmixia, is discussed in terms of power to detect genes under selection and association mapping. Furthermore we provide new statistical methods for use in future analyses of multiparental populations. PMID:25406468

  9. Efficiently Tracking Selection in a Multiparental Population: The Case of Earliness in Wheat

    PubMed Central

    Thépot, Stéphanie; Restoux, Gwendal; Goldringer, Isabelle; Hospital, Frédéric; Gouache, David; Mackay, Ian; Enjalbert, Jérôme

    2015-01-01

    Multiparental populations are innovative tools for fine mapping large numbers of loci. Here we explored the application of a wheat Multiparent Advanced Generation Inter-Cross (MAGIC) population for QTL mapping. This population was created by 12 generations of free recombination among 60 founder lines, following modification of the mating system from strict selfing to strict outcrossing using the ms1b nuclear male sterility gene. Available parents and a subset of 380 SSD lines of the resulting MAGIC population were phenotyped for earliness and genotyped with the 9K i-Select SNP array and additional markers in candidate genes controlling heading date. We demonstrated that 12 generations of strict outcrossing rapidly and drastically reduced linkage disequilibrium to very low levels even at short map distances and also greatly reduced the population structure exhibited among the parents. We developed a Bayesian method, based on allelic frequency, to estimate the contribution of each parent in the evolved population. To detect loci under selection and estimate selective pressure, we also developed a new method comparing shifts in allelic frequency between the initial and the evolved populations due to both selection and genetic drift with expectations under drift only. This evolutionary approach allowed us to identify 26 genomic areas under selection. Using association tests between flowering time and polymorphisms, 6 of these genomic areas appeared to carry flowering time QTL, 1 of which corresponds to Ppd-D1, a major gene involved in the photoperiod sensitivity. Frequency shifts at 4 of 6 areas were consistent with earlier flowering of the evolved population relative to the initial population. The use of this new outcrossing wheat population, mixing numerous initial parental lines through multiple generations of panmixia, is discussed in terms of power to detect genes under selection and association mapping. Furthermore we provide new statistical methods for use in future analyses of multiparental populations. PMID:25406468

  10. DNA markers linked to a T10 loose smut resistance gene in wheat (Triticum aestivum L.).

    PubMed

    Procunier, J D; Gray, M A; Howes, N K; Knox, R E; Bernier, A M

    1997-04-01

    Screening for loose smut resistance in wheat is difficult. Selecting lines with DNA markers linked to loose smut resistance would be more reliable and less costly. Molecular markers linked to a race T10 loose smut resistance gene were identified using a F6 single seed descent segregating population. A RAPD marker and a RFLP marker were located on opposite flanks of the resistance gene and were shown to be loosely linked. The RAPD marker was converted to a user friendly polymorphic SCAR marker that represented a single genetically defined locus in hexaploid wheat. Using these two bracketing markers simultaneously, the error rate for T10 resistance selection due to crossing-over was reduced to 4%. These markers can be used for a faster and more reliable selection of T10 resistant plants than previous conventional loose smut ratings. PMID:18464816

  11. Impact of the D genome and quantitative trait loci on quantitative traits in a spring durum by spring bread wheat cross.

    PubMed

    Kalous, J R; Martin, J M; Sherman, J D; Heo, H-Y; Blake, N K; Lanning, S P; Eckhoff, J L A; Chao, S; Akhunov, E; Talbert, L E

    2015-09-01

    The impact of the D genome and QTL in the A and B genomes on agronomic performance of hexaploid wheat and tetraploid durum was determined using novel recombinant inbred line populations derived from interploid crosses. Genetic differences between common hexaploid (6X) bread wheat (Triticum aestivum, 2n = 6x = 42, genome, AABBDD) and tetraploid (4X) durum wheat (T. turgidum subsp. durum, 2n = 4x = 28, genome, AABB) may exist due to effects of the D genome and allelic differences at loci in the A and B genomes. Previous work allowed identification of a 6X by 4X cross combination that resulted in a large number of fertile recombinant progeny at both ploidy levels. In this study, interspecific recombinant inbred line populations at both 4X and 6X ploidy with 88 and 117 individuals, respectively, were developed from a cross between Choteau spring wheat (6X) and Mountrail durum wheat (4X). The presence of the D genome in the 6X population resulted in increased yield, tiller number, kernel weight, and kernel size, as well as a decrease in stem solidness, test weight and seed per spike. Similar results were found with a second RIL population containing 152 lines from 18 additional 6X by 4X crosses. Several QTL for agronomic and quality traits were identified in both the 4X and 6X populations. Although negatively impacted by the lack of the D genome, kernel weight in Mountrail (4X) was higher than Choteau (6X) due to positive alleles from Mountrail on chromosomes 3B and 7A. These and other favorable alleles may be useful for introgression between ploidy levels. PMID:26037088

  12. Influence of agro-environmental factors on fusarium infestation and population structure in wheat kernels.

    PubMed

    Rohácik, Tibor; Hudec, Kamil

    2005-01-01

    The influence of location, year and cultivar on occurrence, level of infestation and Fusarium species spectrum in winter wheat seeds were evaluated. The wheat seeds from different cultivars and localities of the Slovak Republic were used for Fusarium species evaluation during years 1999, 2000, 2002 and 2003. The significant influence of the locality on total Fusarium kernel infestation was confirmed. The total sample infestation was significantly higher in the colder and moister localities, lower infestation was in warmer and dryer ones. Cultivar "Astella" was significantly the most susceptible. The widest Fusarium species spectrum was recorded in the locations with a high level of total kernel infestation. In localities with lower infestation, the species spectrum was less numerous. F. poae was the dominant species in all locations. The species F. culmorum, F. avenaceum and Microdochium nivale were subdominant and relatively frequent in the locations with higher altitude. The frequency and density of other isolated species (F. graminearum, F. sporotrichioides, F. tricinctum, F. semitectum, F. acuminatum, F. heterosporum, F. sambucinum, F. solani, F. compactum and F. oxysporum) was trivial in all localities. The kernel infestation and Fusarium population structure in wheat grains mostly depends on microclimatic condition of the locality. Rising of rainfall rate and altitude led to an increase in the species spectrum. The wide Fusarium species spectrum is connected with the high frequency of coincident species. The species with low and medium frequency achieved low or trivial density in population structure. PMID:16028865

  13. Ancient DNA from 8400 Year-Old Çatalhöyük Wheat: Implications for the Origin of Neolithic Agriculture.

    PubMed

    Bilgic, Hatice; Hakki, Erdogan E; Pandey, Anamika; Khan, Mohd Kamran; Akkaya, Mahinur S

    2016-01-01

    Human history was transformed with the advent of agriculture in the Fertile Crescent with wheat as one of the founding crops. Although the Fertile Crescent is renowned as the center of wheat domestication, archaeological studies have shown the crucial involvement of Çatalhöyük in this process. This site first gained attention during the 1961-65 excavations due to the recovery of primitive hexaploid wheat. However, despite the seeds being well preserved, a detailed archaeobotanical description of the samples is missing. In this article, we report on the DNA isolation, amplification and sequencing of ancient DNA of charred wheat grains from Çatalhöyük and other Turkish archaeological sites and the comparison of these wheat grains with contemporary wheat species including T. monococcum, T. dicoccum, T. dicoccoides, T. durum and T. aestivum at HMW glutenin protein loci. These ancient samples represent the oldest wheat sample sequenced to date and the first ancient wheat sample from the Middle East. Remarkably, the sequence analysis of the short DNA fragments preserved in seeds that are approximately 8400 years old showed that the Çatalhöyük wheat stock contained hexaploid wheat, which is similar to contemporary hexaploid wheat species including both naked (T. aestivum) and hulled (T. spelta) wheat. This suggests an early transitory state of hexaploid wheat agriculture from the Fertile Crescent towards Europe spanning present-day Turkey. PMID:26998604

  14. Ancient DNA from 8400 Year-Old Çatalhöyük Wheat: Implications for the Origin of Neolithic Agriculture

    PubMed Central

    Bilgic, Hatice; Hakki, Erdogan E.; Akkaya, Mahinur S.

    2016-01-01

    Human history was transformed with the advent of agriculture in the Fertile Crescent with wheat as one of the founding crops. Although the Fertile Crescent is renowned as the center of wheat domestication, archaeological studies have shown the crucial involvement of Çatalhöyük in this process. This site first gained attention during the 1961–65 excavations due to the recovery of primitive hexaploid wheat. However, despite the seeds being well preserved, a detailed archaeobotanical description of the samples is missing. In this article, we report on the DNA isolation, amplification and sequencing of ancient DNA of charred wheat grains from Çatalhöyük and other Turkish archaeological sites and the comparison of these wheat grains with contemporary wheat species including T. monococcum, T. dicoccum, T. dicoccoides, T. durum and T. aestivum at HMW glutenin protein loci. These ancient samples represent the oldest wheat sample sequenced to date and the first ancient wheat sample from the Middle East. Remarkably, the sequence analysis of the short DNA fragments preserved in seeds that are approximately 8400 years old showed that the Çatalhöyük wheat stock contained hexaploid wheat, which is similar to contemporary hexaploid wheat species including both naked (T. aestivum) and hulled (T. spelta) wheat. This suggests an early transitory state of hexaploid wheat agriculture from the Fertile Crescent towards Europe spanning present-day Turkey. PMID:26998604

  15. The genetics of rhizosheath size in a multiparent mapping population of wheat

    PubMed Central

    Delhaize, Emmanuel; Rathjen, Tina M.; Cavanagh, Colin R.

    2015-01-01

    Rhizosheaths comprise soil that adheres to plant roots and, in some species, are indicative of root hair length. In this study, the genetics of rhizosheath size in wheat was investigated by screening the progeny of multiparent advanced generation intercrosses (MAGIC). Two MAGIC populations were screened for rhizosheath size using a high throughput method. One MAGIC population was developed from intercrosses between four parents (4-way) and the other from intercrosses between eight parents (8-way). Transgressive segregation for rhizosheath size was observed in both the 4-way and 8-way MAGIC populations. A quantitative trait loci (QTL) analysis of the 4-way population identified six major loci located on chromosomes 2B, 4D, 5A, 5B, 6A, and 7A together accounting for 42% of the variation in rhizosheath size. Rhizosheath size was strongly correlated with root hair length and was robust across different soil types in the absence of chemical constraints. Rhizosheath size in the MAGIC populations was a reliable surrogate for root hair length and, therefore, the QTL identified probably control root hair elongation. Members of the basic helix-loop-helix family of transcription factors have previously been identified to regulate root hair length in Arabidopsis and rice. Since several wheat members of the basic helix-loop-helix family of genes are located within or near the QTL, these genes are candidates for controlling the long root hair trait. The QTL for rhizosheath size identified in this study provides the opportunity to implement marker-assisted selection to increase root hair length for improved phosphate acquisition in wheat. PMID:25969556

  16. The genetics of rhizosheath size in a multiparent mapping population of wheat.

    PubMed

    Delhaize, Emmanuel; Rathjen, Tina M; Cavanagh, Colin R

    2015-08-01

    Rhizosheaths comprise soil that adheres to plant roots and, in some species, are indicative of root hair length. In this study, the genetics of rhizosheath size in wheat was investigated by screening the progeny of multiparent advanced generation intercrosses (MAGIC). Two MAGIC populations were screened for rhizosheath size using a high throughput method. One MAGIC population was developed from intercrosses between four parents (4-way) and the other from intercrosses between eight parents (8-way). Transgressive segregation for rhizosheath size was observed in both the 4-way and 8-way MAGIC populations. A quantitative trait loci (QTL) analysis of the 4-way population identified six major loci located on chromosomes 2B, 4D, 5A, 5B, 6A, and 7A together accounting for 42% of the variation in rhizosheath size. Rhizosheath size was strongly correlated with root hair length and was robust across different soil types in the absence of chemical constraints. Rhizosheath size in the MAGIC populations was a reliable surrogate for root hair length and, therefore, the QTL identified probably control root hair elongation. Members of the basic helix-loop-helix family of transcription factors have previously been identified to regulate root hair length in Arabidopsis and rice. Since several wheat members of the basic helix-loop-helix family of genes are located within or near the QTL, these genes are candidates for controlling the long root hair trait. The QTL for rhizosheath size identified in this study provides the opportunity to implement marker-assisted selection to increase root hair length for improved phosphate acquisition in wheat. PMID:25969556

  17. Chromosomal Behavior during Meiosis in the Progeny of Triticum timopheevii Hexaploid Wild Oat

    PubMed Central

    An, Hongzhou; Hu, Mei; Li, Pengfei; Geng, Guangdong; Zhang, Qingqin; Zhang, Suqin

    2015-01-01

    The meiotic behavior of pollen mother cells (PMCs) of the F2 and F3 progeny from Triticum timopheevii hexaploid wild oat was investigated by cytological analysis and sequential C-banding-genomic in situ hybridization (GISH) in the present study. A cytological analysis showed that the chromosome numbers of the F2 and F3 progeny ranged from 28 to 41. A large number of univalents, lagging chromosomes, chromosome bridges and micronuclei were found at the metaphase I, anaphase I, anaphase II and tetrad stages in the F2 and F3 progeny. The averages of univalents were 3.50 and 2.73 per cell, and those of lagging chromosomes were 3.37 and 1.87 in the F2 and F3 progeny, respectively. The PMC meiotic indices of the F2 and F3 progeny were 12.22 and 20.34, respectively, indicating considerable genetic instability. A sequential C-banding-GISH analysis revealed that some chromosomes and fragments from the hexaploid wild oat were detected at metaphase I and anaphase I in the progeny, showing that the progeny were of true intergeneric hybrid origin. The alien chromosomes 6A, 7A, 3C and 2D were lost during transmission from F2 to F3. In addition, partial T. timopheevii chromosomes appeared in the form of univalents or lagging chromosomes, which might result from large genome differences between the parents, and the wild oat chromosome introgression interfered with the wheat homologues normally pairing. PMID:25950431

  18. Association Analysis of Historical Bread Wheat Germplasm Using Additive Genetic Covariance of Relatives and Population Structure

    PubMed Central

    Crossa, José; Burgueño, Juan; Dreisigacker, Susanne; Vargas, Mateo; Herrera-Foessel, Sybil A.; Lillemo, Morten; Singh, Ravi P.; Trethowan, Richard; Warburton, Marilyn; Franco, Jorge; Reynolds, Matthew; Crouch, Jonathan H.; Ortiz, Rodomiro

    2007-01-01

    Linkage disequilibrium can be used for identifying associations between traits of interest and genetic markers. This study used mapped diversity array technology (DArT) markers to find associations with resistance to stem rust, leaf rust, yellow rust, and powdery mildew, plus grain yield in five historical wheat international multienvironment trials from the International Maize and Wheat Improvement Center (CIMMYT). Two linear mixed models were used to assess marker–trait associations incorporating information on population structure and covariance between relatives. An integrated map containing 813 DArT markers and 831 other markers was constructed. Several linkage disequilibrium clusters bearing multiple host plant resistance genes were found. Most of the associated markers were found in genomic regions where previous reports had found genes or quantitative trait loci (QTL) influencing the same traits, providing an independent validation of this approach. In addition, many new chromosome regions for disease resistance and grain yield were identified in the wheat genome. Phenotyping across up to 60 environments and years allowed modeling of genotype × environment interaction, thereby making possible the identification of markers contributing to both additive and additive × additive interaction effects of traits. PMID:17947425

  19. Differential gene expression in incompatible interaction between wheat and stripe rust fungus revealed by the cDNA-AFLP and comparison to compatible interaction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Stripe rust of wheat, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important diseases of wheat worldwide. Due to special features of hexaploid wheat with large and complex genome and difficulties for transformation, and of Pst without sexual reproduction and ha...

  20. Evolution of New Disease Specificity at a Single Resistance Locus in a Crop-Weed Complex: Reconstitution of the Lr21 Gene in Wheat.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaf-rust resistance gene Lr21, present in modern varieties of hexaploid wheat, originated in goatgrass Aegilops tauschii Coss., the D genome donor of wheat. The goatgrass donor was collected in Iran where it grows as a weed in wheat fields as part of the native agricultural ecosystem. In order to ...

  1. The Major Threshability Genes Soft Glume (sog) and Tenacious Glume (Tg), of Diploid and Polyploid Wheat, Trace Their Origin to Independent Mutations at Non-Orthogous Loci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Threshability is an important crop domestication trait. The wild wheat progenitors have tough glumes enveloping the floret that make spikes difficult to thresh, whereas cultivated wheats have soft glumes and are free-threshing. In hexaploid wheat, the glume tenacity gene Tg along with the major dome...

  2. Physical mapping of a large plant genome using global high-information-content-fingerprinting: the distal region of the wheat ancestor Aegilops tauschii chromosome 3DS.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Physical maps employing libraries of bacterial artificial chromosome (BAC) clones are essential for comparative genomics and sequencing of large and repetitive genomes such as those of the hexaploid bread wheat. The diploid ancestor of wheat genome, Aegilops tauschii, is used as a resource for wheat...

  3. Discovery and mapping of single feature polymorphisms in wheat using affymetrix arrays

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Single feature polymorphisms (SFPs) can be a rich source of markers for gene mapping and function studies. To explore the feasibility of using the Affymetrix GeneChip to discover and map SFPs in the large hexaploid wheat genome, six wheat varieties of diverse origins were analyzed for significant pr...

  4. Functionality of Chemically Modified Wild-Type, Partial Waxy and Waxy Starches from Tetraploid Wheats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Partial waxy (reduced-amylose) and fully waxy (amylose-free) tetraploid wheats (Triticum turgidum L. var durum) were developed by introgression of null alleles at the Wx-A1 and Wx-B1 loci from common hexaploid wheat (T. aestivum L.). Purified starches were obtained from each genotype, and chemicall...

  5. Rapid development of PCR-based genome-specific repetitive DNA junction markers in wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In hexaploid wheat (Triticum aestivum L.) (AABBDD, C=17,000Mb), repeat DNA accounts for ~ 90% of the genome of which transposable elements (TEs) constitute 60-80 %. Despite the dynamic evolution of TEs, our previous study indicated that the majority of TEs between the homologous wheat genomes are co...

  6. Evidence for stable transformation of wheat by floraldip in Agrobacterium tumefaciens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hexaploid wheat is one of the worlds most important staple crops but genetic transformation is still challenging. We have developed a floral transformation protocol that does not utilize tissue culture. Three T-DNA wheat transformants have been produced in the germplasm line, Crocus, using this p...

  7. Rewiring the wheat reproductive system to harness heterosis for the next wave of yield improvements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bread wheat (hexaploid Triticum aestivum) provides an extraordinary ten-thousand-year story of a new species, established by early farmers, selecting for simple agronomical traits to facilitate efficient and plentiful grain harvest. The genetic changes underlying wheat domestication over thousands ...

  8. Functionality of Native Tetraploid Wheat Starches: Effects of Waxy Loci Alleles and Amylose Concentration in Blends

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Partial waxy (reduced-amylose) and fully waxy (amylose-free) tetraploid durum wheats (Triticum turgidum L. var. durum) were developed by introgression of null alleles at the Wx-A1 and Wx-B1 loci from common hexaploid wheat (T. aestivum L.). These genotypes were used to investigate the relationships...

  9. Transcriptome profiling and expression analyses of genes critical to wheat adaptation to low temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: To identify the genes involved in the development of low temperature (LT) tolerance in hexaploid wheat, we examined the global changes in expression in response to cold of the 55,052 potentially unique genes represented in the Affymetrix Wheat Genome microarray. We compared the expressi...

  10. Differential transmission of Triticum mosaic virus by wheat curl mite populations collected in the Great Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat is an important food grain worldwide, and the primary dryland crop in the western Great Plains. A complex of three wheat curl mite (WCM)-transmitted viruses [Wheat streak mosaic, High plains, and Triticum mosaic viruses (TriMV)] is a cause of serious loss in winter wheat production in the Grea...

  11. The emerging biofuel crop Camelina sativa retains a highly undifferentiated hexaploid genome structure

    PubMed Central

    Kagale, Sateesh; Koh, Chushin; Nixon, John; Bollina, Venkatesh; Clarke, Wayne E.; Tuteja, Reetu; Spillane, Charles; Robinson, Stephen J.; Links, Matthew G.; Clarke, Carling; Higgins, Erin E.; Huebert, Terry; Sharpe, Andrew G.; Parkin, Isobel A. P.

    2014-01-01

    Camelina sativa is an oilseed with desirable agronomic and oil-quality attributes for a viable industrial oil platform crop. Here we generate the first chromosome-scale high-quality reference genome sequence for C. sativa and annotated 89,418 protein-coding genes, representing a whole-genome triplication event relative to the crucifer model Arabidopsis thaliana. C. sativa represents the first crop species to be sequenced from lineage I of the Brassicaceae. The well-preserved hexaploid genome structure of C. sativa surprisingly mirrors those of economically important amphidiploid Brassica crop species from lineage II as well as wheat and cotton. The three genomes of C. sativa show no evidence of fractionation bias and limited expression-level bias, both characteristics commonly associated with polyploid evolution. The highly undifferentiated polyploid genome of C. sativa presents significant consequences for breeding and genetic manipulation of this industrial oil crop. PMID:24759634

  12. The emerging biofuel crop Camelina sativa retains a highly undifferentiated hexaploid genome structure.

    PubMed

    Kagale, Sateesh; Koh, Chushin; Nixon, John; Bollina, Venkatesh; Clarke, Wayne E; Tuteja, Reetu; Spillane, Charles; Robinson, Stephen J; Links, Matthew G; Clarke, Carling; Higgins, Erin E; Huebert, Terry; Sharpe, Andrew G; Parkin, Isobel A P

    2014-01-01

    Camelina sativa is an oilseed with desirable agronomic and oil-quality attributes for a viable industrial oil platform crop. Here we generate the first chromosome-scale high-quality reference genome sequence for C. sativa and annotated 89,418 protein-coding genes, representing a whole-genome triplication event relative to the crucifer model Arabidopsis thaliana. C. sativa represents the first crop species to be sequenced from lineage I of the Brassicaceae. The well-preserved hexaploid genome structure of C. sativa surprisingly mirrors those of economically important amphidiploid Brassica crop species from lineage II as well as wheat and cotton. The three genomes of C. sativa show no evidence of fractionation bias and limited expression-level bias, both characteristics commonly associated with polyploid evolution. The highly undifferentiated polyploid genome of C. sativa presents significant consequences for breeding and genetic manipulation of this industrial oil crop. PMID:24759634

  13. Transcript profiling of wheat genes expressed during feeding by two different biotypes of Diuraphis noxia.

    PubMed

    Botha, Anna-Maria; Swanevelder, Zacharias H; Lapitan, Nora L V

    2010-08-01

    Diuraphis noxia (Kurdjumov)(Russian wheat aphid) has severe economic impacts on wheat and barley production in the United States. The interaction between the Russian wheat aphid and its cereal hosts is poorly understood. However, the recent appearance of new biotypes in the United States showed that specific interactions exist between wheat resistance loci and Russian wheat aphid biotypes. At present, Dn7 is the only known gene in hexaploid wheat that confers resistance against all U.S. Russian wheat aphid biotypes. This study was conducted to investigate the molecular mechanism of Dn7-mediated resistance against two U.S. Russian wheat aphid biotypes (Russian wheat aphid 1 and Russian wheat aphid 2). Using GeneChip Wheat Genome Arrays, we compared transcript profiles of resistant and susceptible lines infested with either Russian wheat aphid 1 or Russian wheat aphid 2 using two time intervals (5 and 48 h after infestation). Russian wheat aphid feeding on hexaploid wheat led to the induction of groups of genes functioning in oxidative and general stress, photosynthesis, cell respiration and energy production, signal transduction, calcium-dependent signaling, pathogenesis related (PR) responses, and defense compound synthesis. The number of differentially expressed genes was higher in plants infested with Russian wheat aphid 1 compared with those infested with Russian wheat aphid 2. Although most genes involved in basic cellular functions were shared, unique genes were also obtained. This finding may indicate subtle differences in genes induced in response to different virulence proteins. PMID:22127172

  14. Characterization of Ferredoxin-Dependent Glutamine-Oxoglutarate Amidotransferase (Fd-GOGAT) Genes and Their Relationship with Grain Protein Content QTL in Wheat

    PubMed Central

    2014-01-01

    Background In higher plants, inorganic nitrogen is assimilated via the glutamate synthase cycle or GS-GOGAT pathway. GOGAT enzyme occurs in two distinct forms that use NADH (NADH-GOGAT) or Fd (Fd-GOGAT) as electron carriers. The goal of the present study was to characterize wheat Fd-GOGAT genes and to assess the linkage with grain protein content (GPC), an important quantitative trait controlled by multiple genes. Results We report the complete genomic sequences of the three homoeologous A, B and D Fd-GOGAT genes from hexaploid wheat (Triticum aestivum) and their localization and characterization. The gene is comprised of 33 exons and 32 introns for all the three homoeologues genes. The three genes show the same exon/intron number and size, with the only exception of a series of indels in intronic regions. The partial sequence of the Fd-GOGAT gene located on A genome was determined in two durum wheat (Triticum turgidum ssp. durum) cvs Ciccio and Svevo, characterized by different grain protein content. Genomic differences allowed the gene mapping in the centromeric region of chromosome 2A. QTL analysis was conducted in the Svevo×Ciccio RIL mapping population, previously evaluated in 5 different environments. The study co-localized the Fd-GOGAT-A gene with the marker GWM-339, identifying a significant major QTL for GPC. Conclusions The wheat Fd-GOGAT genes are highly conserved; both among the three homoeologous hexaploid wheat genes and in comparison with other plants. In durum wheat, an association was shown between the Fd-GOGAT allele of cv Svevo with increasing GPC - potentially useful in breeding programs. PMID:25099972

  15. Reconstruction of the synthetic W7984 x Opata M85 wheat reference population.

    PubMed

    Sorrells, Mark E; Gustafson, J Perry; Somers, Daryl; Chao, Shiaoman; Benscher, David; Guedira-Brown, Gina; Huttner, Eric; Kilian, Andrezj; McGuire, Patrick E; Ross, Kathleen; Tanaka, James; Wenzl, Peter; Williams, Keith; Qualset, Calvin O

    2011-11-01

    Reference populations are valuable resources in genetics studies for determining marker order, marker selection, trait mapping, construction of large-insert libraries, cross-referencing marker platforms, and genome sequencing. Reference populations can be propagated indefinitely, they are polymorphic and have normal segregation. Described are two new reference populations who share the same parents of the original wheat reference population Synthetic W7984 (Altar84/ Aegilops tauschii (219) CIGM86.940) x Opata M85, an F(1)-derived doubled haploid population (SynOpDH) of 215 inbred lines and a recombinant inbred population (SynOpRIL) of 2039 F(6) lines derived by single-plant self-pollinations. A linkage map was constructed for the SynOpDH population using 1446 markers. In addition, a core set of 42 SSR markers was genotyped on SynOpRIL. A new approach to identifying a core set of markers used a step-wise selection protocol based on polymorphism, uniform chromosome distribution, and reliability to create nested sets starting with one marker per chromosome, followed by two, four, and six. It is suggested that researchers use these markers as anchors for all future mapping projects to facilitate cross-referencing markers and chromosome locations. To enhance this public resource, researchers are strongly urged to validate line identities and deposit their data in GrainGenes so that others can benefit from the accumulated information. PMID:21999208

  16. Worldwide population structure of the wheat rust fungus Puccinia striiformis in the past.

    PubMed

    Thach, T; Ali, S; de Vallavieille-Pope, C; Justesen, A F; Hovmller, M S

    2016-02-01

    Puccinia striiformis is a basidiomycete causing yellow rust on wheat. The availability of historic samples of this pathogen from the 'Stubbs collection' enabled us to investigate past population structure and temporal dynamics on a global scale. A set of 212 single genotype urediniospore isolates, representing samples collected from five continents between 1958 and 1991, were genotyped using 19 polymorphic microsatellite markers. The population genetic analyses revealed the existence of seven genetic groups in the past worldwide P. striiformis population. This genetic grouping generally corresponded with geographical sample origin except for the Middle East, where six of the seven genetic groups were represented. The presence of many genetic groups in the Middle Eastern population reflected a low differentiation from the populations in East Africa (FST=0.052) and in South Asia (FST=0.064). A high diversity and recombinant population structure was observed in China and South Asia, while a clonal population structure was observed in NW Europe, East Africa and the Mediterranean region. The high genetic diversity in the Himalayan region supported recent studies suggesting a putative center of diversity for P. striiformis in this area. Four of the 89 multilocus genotypes detected were resampled in different geographical regions suggesting long-distance migration in the past. Comparison of the past populations with more recent ones, represented by 309 isolates mainly collected between 2001 and 2009, revealed temporal divergence for all populations except for Northwest Europe. Overall, we observed a clear subdivision within the worldwide population structure of P. striiformis and migration in the past. PMID:26724600

  17. Genetic Relationships, Carbendazim Sensitivity and Mycotoxin Production of the Fusarium Graminearum Populations from Maize, Wheat and Rice in Eastern China

    PubMed Central

    Qiu, Jianbo; Shi, Jianrong

    2014-01-01

    Members of the Fusarium graminearum species complex (FGSC) are important pathogens on wheat, maize, barley, and rice in China. Harvested grains are often contaminated by mycotoxins, such as the trichothecene nivalenol (NIV) and deoxynivalenol (DON) and the estrogenic mycotoxin zearalenone (ZEN), which is a big threat to humans and animals. In this study, 97 isolates were collected from maize, wheat, and rice in Jiangsu and Anhui provinces in 2013 and characterized by species- and chemotype-specific PCR. F. graminearum sensu stricto (s. str.) was predominant on maize, while most of the isolates collected from rice and wheat were identified as F. asiaticum. Fusarium isolates from three hosts varied in trichothecene chemotypes. The 3-acetyldeoxynivalenol (3ADON) chemotype predominated on wheat and rice population, while 15ADON was prevailing in the remaining isolates. Sequence analysis of the translation elongation factor 1α and trichodiene synthase indicated the accuracy of the above conclusion. Additionally, phylogenetic analysis suggested four groups with strong correlation with species, chemotype, and host. These isolates were also evaluated for their sensitivity to carbendazim and mycotoxins production. The maize population was less sensitive than the other two. The DON levels were similar in three populations, while those isolates on maize produced more ZEN. More DON was produced in carbendazim resistant strains than sensitive ones, but it seemed that carbendazim resistance had no effect on ZEN production in wheat culture. PMID:25093387

  18. Population subdivision of Fusarium graminearum from barley and wheat in the upper Midwestern United States at the turn of the century

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium graminearum, the causal agent of Fusarium head blight (FHB) in wheat and barley, is one of the most economically destructive pathogens of these grains worldwide. Recent population genetic studies of the pathogen obtained from wheat in North America supported population subdivision in part c...

  19. Natural Lactic Acid Bacteria Population and Silage Fermentation of Whole-crop Wheat

    PubMed Central

    Ni, Kuikui; Wang, Yanping; Cai, Yimin; Pang, Huili

    2015-01-01

    Winter wheat is a suitable crop to be ensiled for animal feed and China has the largest planting area of this crop in the world. During the ensiling process, lactic acid bacteria (LAB) play the most important role in the fermentation. We investigated the natural population of LAB in whole-crop wheat (WCW) and examined the quality of whole-crop wheat silage (WCWS) with and without LAB inoculants. Two Lactobacillus plantarum subsp. plantarum strains, Zhengzhou University 1 (ZZU 1) selected from corn and forage and grass 1 (FG 1) from a commercial inoculant, were used as additives. The silages inoculated with LAB strains (ZZU 1 and FG 1) were better preserved than the control, with lower pH values (3.5 and 3.6, respectively) (p<0.05) and higher contents of lactic acid (37.5 and 34.0 g/kg of fresh matter (FM), respectively) (p<0.05) than the control. Sixty LAB strains were isolated from fresh material and WCWS without any LAB inoculation. These LAB strains were divided into the following four genera and six species based on their phenotypic, biochemical and phylogenetic characteristics: Leuconostoc pseudomesenteroides, Leuconostoc citreum, Weissella cibaria, Lactococcus lactis subsp. lactis, Lactobacillus buchneri, and Lactobacillus plantarum subsp. plantarum. However, the prevalent LAB, which was predominantly heterofermentative (66.7%), consisted of Leuconostoc pseudomesenteroides, Leuconostoc citreum, Weissella cibaria, and Lactobacillus buchneri. This study revealed that most of isolated LAB strains from control WCWS were heterofermentative and could not grow well at low pH condition; the selective inoculants of Lactobacillus strains, especially ZZU 1, could improve WCWS quality significantly. PMID:26104520

  20. Natural Lactic Acid Bacteria Population and Silage Fermentation of Whole-crop Wheat.

    PubMed

    Ni, Kuikui; Wang, Yanping; Cai, Yimin; Pang, Huili

    2015-08-01

    Winter wheat is a suitable crop to be ensiled for animal feed and China has the largest planting area of this crop in the world. During the ensiling process, lactic acid bacteria (LAB) play the most important role in the fermentation. We investigated the natural population of LAB in whole-crop wheat (WCW) and examined the quality of whole-crop wheat silage (WCWS) with and without LAB inoculants. Two Lactobacillus plantarum subsp. plantarum strains, Zhengzhou University 1 (ZZU 1) selected from corn and forage and grass 1 (FG 1) from a commercial inoculant, were used as additives. The silages inoculated with LAB strains (ZZU 1 and FG 1) were better preserved than the control, with lower pH values (3.5 and 3.6, respectively) (p<0.05) and higher contents of lactic acid (37.5 and 34.0 g/kg of fresh matter (FM), respectively) (p<0.05) than the control. Sixty LAB strains were isolated from fresh material and WCWS without any LAB inoculation. These LAB strains were divided into the following four genera and six species based on their phenotypic, biochemical and phylogenetic characteristics: Leuconostoc pseudomesenteroides, Leuconostoc citreum, Weissella cibaria, Lactococcus lactis subsp. lactis, Lactobacillus buchneri, and Lactobacillus plantarum subsp. plantarum. However, the prevalent LAB, which was predominantly heterofermentative (66.7%), consisted of Leuconostoc pseudomesenteroides, Leuconostoc citreum, Weissella cibaria, and Lactobacillus buchneri. This study revealed that most of isolated LAB strains from control WCWS were heterofermentative and could not grow well at low pH condition; the selective inoculants of Lactobacillus strains, especially ZZU 1, could improve WCWS quality significantly. PMID:26104520

  1. Identifying Rare FHB-Resistant Segregants in Intransigent Backcross and F2 Winter Wheat Populations

    PubMed Central

    Clark, Anthony J.; Sarti-Dvorjak, Daniela; Brown-Guedira, Gina; Dong, Yanhong; Baik, Byung-Kee; Van Sanford, David A.

    2016-01-01

    Fusarium head blight (FHB), caused mainly by Fusarium graminearum Schwabe [telomorph: Gibberella zeae Schwein.(Petch)] in the US, is one of the most destructive diseases of wheat (Triticum aestivum L. and T. durum L.). Infected grain is usually contaminated with deoxynivalenol (DON), a serious mycotoxin. The challenge in FHB resistance breeding is combining resistance with superior agronomic and quality characteristics. Exotic QTL are widely used to improve FHB resistance. Success depends on the genetic background into which the QTL are introgressed, whether through backcrossing or forward crossing; QTL expression is impossible to predict. In this study four high-yielding soft red winter wheat breeding lines with little or no scab resistance were each crossed to a donor parent (VA01W-476) with resistance alleles at two QTL: Fhb1 (chromosome 3BS) and QFhs.nau-2DL (chromosome 2DL) to generate backcross and F2 progeny. F2 individuals were genotyped and assigned to 4 groups according to presence/ absence of resistance alleles at one or both QTL. The effectiveness of these QTL in reducing FHB rating, incidence, index, severity, Fusarium-damaged kernels (FDK) and DON, in F2-derived lines was assessed over 2 years. Fhb1 showed an average reduction in DON of 17.5%, and conferred significant resistance in 3 of 4 populations. QFhs.nau-2DL reduced DON 6.7% on average and conferred significant resistance in 2 of 4 populations. The combination of Fhb1 and QFhs.nau-2DL resistance reduced DON 25.5% across all populations. Double resistant lines had significantly reduced DON compared to double susceptible lines in 3 populations. Backcross derived progeny were planted in replicated yield trials (2011 and 2012) and in a scab nursery in 2012. Several top yielding lines performed well in the scab nursery, with acceptable DON concentrations, even though the average effect of either QTL in this population was not significant. Population selection is often viewed as an “all or nothing” process: if the average resistance level is insufficient, the population is discarded. These results indicate that it may be possible to find rare segregants which combine scab resistance, superior agronomic performance and acceptable quality even in populations in which the average effect of the QTL is muted or negligible. PMID:27014202

  2. Rapid Differentiation of Experimental Populations of Wheat for Heading Time in Response to Local Climatic Conditions

    PubMed Central

    GOLDRINGER, ISABELLE; PROUIN, CLAIRE; ROUSSET, MICHEL; GALIC, NATHALIE; BONNIN, ISABELLE

    2006-01-01

    • Background and Aims Dynamic management (DM) of genetic resources aims at maintaining genetic variability between different populations evolving under natural selection in contrasting environments. In 1984, this strategy was applied in a pilot experiment on wheat (Triticum aestivum). Spatio-temporal evolution of earliness and its components (partial vernalization sensitivity, daylength sensitivity and earliness per se that determines flowering time independently of environmental stimuli) was investigated in this multisite and long-term experiment. • Methods Heading time of six populations from the tenth generation was evaluated under different vernalization and photoperiodic conditions. • Key Results Although temporal evolution during ten generations was not significant, populations of generation 10 were genetically differentiated according to a north–south latitudinal trend for two components out of three: partial vernalization sensitivity and narrow-sense earliness. • Conclusions It is concluded that local climatic conditions greatly influenced the evolution of population earliness, thus being a major factor of differentiation in the DM system. Accordingly, a substantial proportion (∼25 %) of genetic variance was distributed among populations, suggesting that diversity was on average conserved during evolution but was differently distributed by natural selection (and possibly drift). Earliness is a complex trait and each genetic factor is controlled by multiple homeoalleles; the next step will be to look for spatial divergence in allele frequencies. PMID:16868000

  3. Use of a large multiparent wheat mapping population in genomic dissection of coleoptile and seedling growth.

    PubMed

    Rebetzke, Greg J; Verbyla, Arunas P; Verbyla, Klara L; Morell, Matthew K; Cavanagh, Colin R

    2014-02-01

    Identification of alleles towards the selection for improved seedling vigour is a key objective of many wheat breeding programmes. A multiparent advanced generation intercross (MAGIC) population developed from four commercial spring wheat cultivars (cvv. Baxter, Chara, Westonia and Yitpi) and containing ca. 1000 F(2) -derived, F(6:7) RILs was assessed at two contrasting soil temperatures (12 and 20 C) for shoot length and coleoptile characteristics length and thickness. Narrow-sense heritabilities were high for coleoptile and shoot length (h(2) = 0.68-0.70), indicating a strong genetic basis for the differences among progeny. Genotypic variation was large, and distributions of genotype means were approximately Gaussian with evidence for transgressive segregation for all traits. A number of significant QTL were identified for all early growth traits, and these were commonly repeatable across the different soil temperatures. The largest negative effects on coleoptile lengths were associated with Rht-B1b (-8.2%) and Rht-D1b (-10.9%) dwarfing genes varying in the population. Reduction in coleoptile length with either gene was particularly large at the warmer soil temperature. Other large QTL for coleoptile length were identified on chromosomes 1A, 2B, 4A, 5A and 6B, but these were relatively smaller than allelic effects at the Rht-B1 and Rht-D1 loci. A large coleoptile length effect allele (a = 5.3 mm at 12 C) was identified on chromosome 1AS despite the relatively shorter coleoptile length of the donor Yitpi. Strong, positive genetic correlations for coleoptile and shoot lengths (r(g) = 0.85-0.90) support the co-location of QTL for these traits and suggest a common physiological basis for both. The multiparent population has enabled the identification of promising shoot and coleoptile QTL despite the potential for the confounding of large effect dwarfing gene alleles present in the commercial parents. The incidence of these alleles in commercial wheat breeding programmes should facilitate their ready implementation in selection of varieties with improved establishment and early growth. PMID:24151921

  4. GENETIC CHARACTERIZATION AND MOLECULAR MAPPING OF HESSIAN FLY RESISTANCE GENES DERIVED FROM TRITICUM TAUSCHII IN SYNTHETIC WHEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two synthetic hexaploid wheat lines (Aegilotriticum spp., 2n=6x=42, genomes AABBDD), SW8 and SW34, developed from the crosses of the durum wheat cultivar Langdon (Triticum turgidum L. var. durum, 2n=4x=28, genomes AABB) with two T. tauschii (Coss.) Schmal accessions (2n=2x=14, genome DD), were dete...

  5. PHENOTYPIC ASSESSMENT AND MAPPED MARKERS FOR H31, A NEW WHEAT GENE CONFERRING RESISTANCE TO HESSIAN FLY (DIPTERA: CECIDOMYIIDAE)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new source of resistance to the highly virulent and widespread biotype L of the Hessian fly, Mayetiola destructor (Say), was identified in an accession of tetraploid durum wheat, Triticum turgidum Desf., and was introgressed into hexaploid common wheat, T. aestivum L. Genetic analysis revealed th...

  6. A BAC-based physical map of Brachypodium distachyon and its comparative analysis with rice and wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The wheat high molecular weight (HMW)-glutenins are important seed storage proteins that determine bread-making quality in hexaploid wheat (Triticum aestivum). In this study, detailed comparative sequence analyses of large orthologous HMW-glutenin genomic regions from eight grass species, represent...

  7. POPULATION DYNAMICS IN THE FIELD OF A BIOCONTROL AGENT FOR FUSARIUM HEAD BLIGHT OF WHEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gibberella zeae (anamorph Fusarium graminearum) is the major causal organism of Fusarium head blight (FHB) on wheat and barley. Wheat anthers are an important site of infection. Application of Crytococcus nodaensis OH 182.9 to wheat heads at the time of flowering reduces FHB. The goal of this res...

  8. POPULATION GENETICS OF THE WHEAT LEAF RUST FUNGUS, PUCCINIA TRITICINA IN CENTRAL ASIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat leaf rust, caused by Puccinia triticina, is a major disease of wheat in Central Asia. Single uredinial isolates from Armenia, Azerbaijan, Tajikistan, Kazakhstan, Uzbekistan, and Kyrgyzstan, 131 in total, were tested for virulence to 20 isolines of Thatcher wheat with single leaf rust resistanc...

  9. POPULATION GENETICS OF THE WHEAT LEAF RUST FUNGUS, PUCCINIA TRITICINA IN CENTRAL ASIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat leaf rust, caused by Puccinia triticina, is a major disease of wheat in Central Asia. Single uredinial isolates from Armenia, Azerbaijan, Tajikistan, Kazakhstan, Uzbekistan, and Kyrgyzstan, 131 in total, were tested for virulence to 20 isolines of Thatcher wheat with single leaf rust resistan...

  10. Population dynamics of the fusarium head blight biocontrol agent cryptococcus flavescens OH182.9 on wheat anthers and heads

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cryptococcus flavescens OH 182.9 (NRRL Y-30216) reduces Fusarium head blight (FHB) incited by Fusarium graminearum and DON contamination of grain in greenhouse and field settings. Yet little is known about the population dynamics of OH 182.9 on wheat heads and anthers from the time of inoculating he...

  11. Aphid resistance in wheat varieties.

    PubMed

    Elek, Henriett; Werner, Peter; Smart, Lesley; Gordon-Weeks, Ruth; Nádasy, Miklós; Pickett, John

    2009-01-01

    As an environmentally compatible alternative to the use of conventional insecticides to control cereal aphids, we have investigated the possibility to exploit natural resistance to insect pests in wheat varieties. We have tested a wide range of hexaploid (Triticum aestivum), tetraploid (T. durum) and diploid (T. boeoticum and T. monococcum) wheat lines for resistance to the bird cherry oat aphid (Rhopalosiphum padi). Lines tested included Russian wheat aphid (Diuraphis noxia), greenbug (Schizaphis graminum), hessian fly (Mayetiola destructor) and orange wheat blossom midge (Sitodiplosis mosellana) resistant varieties. Antixenosis and antibiosis were determined in the settling and fecundity tests respectively. Since hydroxamic acids (Hx), including the most generally active, 2,4-dihidroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), are biosynthesised in many cereal plants and are implicated in resistance against insects, leaf tissue was analysed for Hx and the glucosides from which they are produced. The hexaploid varieties, which contained relatively low levels of the DIMBOA glucoside, did not deter aphid feeding or reduce nymph production significantly. Reduced settlement and nymph production were recorded on the diploid varieties, but they contained no detectable level of the glucoside or the toxic aglucone. PMID:20218532

  12. Experimental Estimation of Mutation Rates in a Wheat Population With a Gene Genealogy Approach

    PubMed Central

    Raquin, Anne-Laure; Depaulis, Frantz; Lambert, Amaury; Galic, Nathalie; Brabant, Philippe; Goldringer, Isabelle

    2008-01-01

    Microsatellite markers are extensively used to evaluate genetic diversity in natural or experimental evolving populations. Their high degree of polymorphism reflects their high mutation rates. Estimates of the mutation rates are therefore necessary when characterizing diversity in populations. As a complement to the classical experimental designs, we propose to use experimental populations, where the initial state is entirely known and some intermediate states have been thoroughly surveyed, thus providing a short timescale estimation together with a large number of cumulated meioses. In this article, we derived four original gene genealogy-based methods to assess mutation rates with limited bias due to relevant model assumptions incorporating the initial state, the number of new alleles, and the genetic effective population size. We studied the evolution of genetic diversity at 21 microsatellite markers, after 15 generations in an experimental wheat population. Compared to the parents, 23 new alleles were found in generation 15 at 9 of the 21 loci studied. We provide evidence that they arose by mutation. Corresponding estimates of the mutation rates ranged from 0 to 4.97 10?3 per generation (i.e., year). Sequences of several alleles revealed that length polymorphism was only due to variation in the core of the microsatellite. Among different microsatellite characteristics, both the motif repeat number and an independent estimation of the Nei diversity were correlated with the novel diversity. Despite a reduced genetic effective size, global diversity at microsatellite markers increased in this population, suggesting that microsatellite diversity should be used with caution as an indicator in biodiversity conservation issues. PMID:18689900

  13. An eight-parent multiparent advanced generation inter-cross population for winter-sown wheat: creation, properties, and validation.

    PubMed

    Mackay, Ian J; Bansept-Basler, Pauline; Barber, Toby; Bentley, Alison R; Cockram, James; Gosman, Nick; Greenland, Andy J; Horsnell, Richard; Howells, Rhian; O'Sullivan, Donal M; Rose, Gemma A; Howell, Phil J

    2014-09-01

    MAGIC populations represent one of a new generation of crop genetic mapping resources combining high genetic recombination and diversity. We describe the creation and validation of an eight-parent MAGIC population consisting of 1091 F7 lines of winter-sown wheat (Triticum aestivum L.). Analyses based on genotypes from a 90,000-single nucleotide polymorphism (SNP) array find the population to be well-suited as a platform for fine-mapping quantitative trait loci (QTL) and gene isolation. Patterns of linkage disequilibrium (LD) show the population to be highly recombined; genetic marker diversity among the founders was 74% of that captured in a larger set of 64 wheat varieties, and 54% of SNPs segregating among the 64 lines also segregated among the eight founder lines. In contrast, a commonly used reference bi-parental population had only 54% of the diversity of the 64 varieties with 27% of SNPs segregating. We demonstrate the potential of this MAGIC resource by identifying a highly diagnostic marker for the morphological character "awn presence/absence" and independently validate it in an association-mapping panel. These analyses show this large, diverse, and highly recombined MAGIC population to be a powerful resource for the genetic dissection of target traits in wheat, and it is well-placed to efficiently exploit ongoing advances in phenomics and genomics. Genetic marker and trait data, together with instructions for access to seed, are available at http://www.niab.com/MAGIC/. PMID:25237112

  14. An Eight-Parent Multiparent Advanced Generation Inter-Cross Population for Winter-Sown Wheat: Creation, Properties, and Validation

    PubMed Central

    Mackay, Ian J.; Bansept-Basler, Pauline; Barber, Toby; Bentley, Alison R.; Cockram, James; Gosman, Nick; Greenland, Andy J.; Horsnell, Richard; Howells, Rhian; O’Sullivan, Donal M.; Rose, Gemma A.; Howell, Phil J.

    2014-01-01

    MAGIC populations represent one of a new generation of crop genetic mapping resources combining high genetic recombination and diversity. We describe the creation and validation of an eight-parent MAGIC population consisting of 1091 F7 lines of winter-sown wheat (Triticum aestivum L.). Analyses based on genotypes from a 90,000-single nucleotide polymorphism (SNP) array find the population to be well-suited as a platform for fine-mapping quantitative trait loci (QTL) and gene isolation. Patterns of linkage disequilibrium (LD) show the population to be highly recombined; genetic marker diversity among the founders was 74% of that captured in a larger set of 64 wheat varieties, and 54% of SNPs segregating among the 64 lines also segregated among the eight founder lines. In contrast, a commonly used reference bi-parental population had only 54% of the diversity of the 64 varieties with 27% of SNPs segregating. We demonstrate the potential of this MAGIC resource by identifying a highly diagnostic marker for the morphological character "awn presence/absence" and independently validate it in an association-mapping panel. These analyses show this large, diverse, and highly recombined MAGIC population to be a powerful resource for the genetic dissection of target traits in wheat, and it is well-placed to efficiently exploit ongoing advances in phenomics and genomics. Genetic marker and trait data, together with instructions for access to seed, are available at http://www.niab.com/MAGIC/. PMID:25237112

  15. Homoeologous copy-specific expression patterns of MADS-box genes for floral formation in allopolyploid wheat.

    PubMed

    Tanaka, Miku; Tanaka, Hiroko; Shitsukawa, Naoki; Kitagawa, Satoshi; Takumi, Shigeo; Murai, Koji

    2016-01-01

    The consensus model for floral organ formation in higher plants, the so-called ABCDE model, proposes that floral whorl-specific combinations of class A, B, C, D, and E genes specify floral organ identity. Class A, B, C, D and E genes encode MADS-box transcription factors; the single exception being the class A gene APETALA2. Bread wheat (Triticum aestivum) is a hexaploid species with a genome constitution AABBDD; the hexaploid originated from a cross between tetraploid T. turgidum (AABB) and diploid Aegilops tauschii (DD). Tetraploid wheat is thought to have originated from a cross between the diploid species T. urartu (AA) and Ae. speltoides (BB). Consequently, the hexaploid wheat genome contains triplicated homoeologous copies (homoeologs) of each gene derived from the different ancestral diploid species. In this study, we examined the expression patterns of homoeologs of class B, C and D MADS-box genes during floral development. For the class B gene wheat PISTILLATA2 (WPI2), the homoeologs from the A and D genomes were expressed, while expression of the B genome homoeolog was suppressed. For the class C gene wheat AGAMOUS1 (WAG1), the homoeologs on the A and B genomes were expressed, while expression of the D genome homoeolog was suppressed. For the class D gene wheat SEEDSTICK (WSTK), the B genome homoeolog was preferentially expressed. These differential patterns of homoeolog expression were consistently observed among different hexaploid wheat varieties and synthetic hexaploid wheat lines developed by artificial crosses between tetraploid wheat and Ae. tauschii. These results suggest that homoeolog-specific regulation of the floral MADS-box genes occurs in allopolyploid wheat. PMID:26616759

  16. Genetic Diversity and Population Structure of Tetraploid Wheats (Triticum turgidum L.) Estimated by SSR, DArT and Pedigree Data

    PubMed Central

    Laid, Giovanni; Mangini, Giacomo; Taranto, Francesca; Gadaleta, Agata; Blanco, Antonio; Cattivelli, Luigi; Marone, Daniela; Mastrangelo, Anna M.; Papa, Roberto; De Vita, Pasquale

    2013-01-01

    Levels of genetic diversity and population genetic structure of a collection of 230 accessions of seven tetraploid Triticum turgidum L. subspecies were investigated using six morphological, nine seed storage protein loci, 26 SSRs and 970 DArT markers. The genetic diversity of the morphological traits and seed storage proteins was always lower in the durum wheat compared to the wild and domesticated emmer. Using Bayesian clustering (K?=?2), both of the sets of molecular markers distinguished the durum wheat cultivars from the other tetraploid subspecies, and two distinct subgroups were detected within the durum wheat subspecies, which is in agreement with their origin and year of release. The genetic diversity of morphological traits and seed storage proteins was always lower in the improved durum cultivars registered after 1990, than in the intermediate and older ones. This marked effect on diversity was not observed for molecular markers, where there was only a weak reduction. At K >2, the SSR markers showed a greater degree of resolution than for DArT, with their identification of a greater number of groups within each subspecies. Analysis of DArT marker differentiation between the wheat subspecies indicated outlier loci that are potentially linked to genes controlling some important agronomic traits. Among the 211 loci identified under selection, 109 markers were recently mapped, and some of these markers were clustered into specific regions on chromosome arms 2BL, 3BS and 4AL, where several genes/quantitative trait loci (QTLs) are involved in the domestication of tetraploid wheats, such as the tenacious glumes (Tg) and brittle rachis (Br) characteristics. On the basis of these results, it can be assumed that the population structure of the tetraploid wheat collection partially reflects the evolutionary history of Triticum turgidum L. subspecies and the genetic potential of landraces and wild accessions for the detection of unexplored alleles. PMID:23826256

  17. Variation among hexaploid Paspalum dilatum Poir. regenerants from tissue culture.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The common biotype of Paspalum dilatatum, called paspalum in Australia and dallisgrass in the U.S.A., is a pentaploid obligate apomict and efforts to improve the grass have not been successful because of its asexual reproduction and irregular meiosis. An apomictic hexaploid biotype, known as Urugua...

  18. Comparative growth and development of hexaploid and tetraploid reed canarygrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reed canarygrass (Phalaris arundinacea L.) is a globally distributed forage species, a potential biofuel, and an important invasive weed. At more northern latitudes in exists as a tetraploid and at equatorial to mid-latitudes as a hexaploid, especially in Mediterranean climates. Growth and developme...

  19. Registration of wheat lines carrying the partial stripe rust resistance gene Yr36 without the Gpc-B1 high grain protein content allele

    PubMed Central

    Hale, I; Zhang, X; Fu, D; Dubcovsky, J

    2016-01-01

    While the high-temperature adult plant resistance gene Yr36 represents a promising source of quantitative and potentially race non-specific resistance to wheat stripe rust (causal organism Puccinia striiformis Westend. f. sp. tritici), its tight linkage (0.3 cM) with the high-grain protein content gene Gpc-B1 may hinder its introgression in certain cases, such as in soft wheat varieties requiring low grain protein content or in lines where the Gpc-B1 allele may be associated with a yield penalty. The development and registration of two donor lines, one tetraploid (Triticum turgidum L. ssp. durum; PI 656793) and one hexaploid (T. aestivum L. ssp. aestivum; PI 664549), each carrying the resistant wild emmer (T. turgidum ssp. dicoccoides) allele for Yr36 linked with the non-functional Gpc-B1 allele, are intended to overcome this potential limitation. Meiotic recombination events breaking the linkage between these two genes were discovered during the systematic screening of a population of 4,500 F2 durum plants (cv. Langdon background) used to fine map Yr36. One of the critical recombination events was selected for fixation by self-pollination and transferred to a California adapted spring hexaploid background (breeding line UC11105+10) through five generations of backcrossing. Genotypic and phenotypic data confirm the presence of Yr36 and the non-functional Gpc-B1 allele in both registered lines.

  20. New QTL alleles for quality-related traits in spring wheat revealed by RIL population derived from supernumerary x non-supernumerary spikelet genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Identifying new quantitative trait loci (QTLs) and alleles in exotic germplasm is paramount for further improvement of quality traits in wheat. In the present study, a population of recombinant inbred lines (RILs) developed from a cross between an elite wheat line (WCB414) and an exotic genotype wi...

  1. Genome-wide mapping of spike-related and agronomic traits in a common wheat population derived from a supernumerary parent and an elite parent

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In wheat (Triticum aestivum L), exotic genotypes express a broad range of spike-related traits and could be used as a source of new genes to enrich the germplasm for wheat breeding programs. In the present study, a population of 163 recombinant inbred lines derived from a cross between an elite line...

  2. New QTL alleles for quality-related traits in spring wheat revealed by RIL population derived from supernumerary x non-supernumerary spikelet genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Identifying new QTLs and alleles in exotic germplasm is paramount for further improvement of quality traits in wheat. In the present study, a RIL population developed from a cross of an elite wheat line (WCB414) and an exotic genotype with supernumerary spikelets (SS) was used to identify QTLs and n...

  3. Population genetics of wolf spiders of fragmented habitat in the wheat belt of New South Wales.

    PubMed

    Colgan, D J; Brown, S; Major, R E; Christie, F; Gray, M R; Cassis, G

    2002-11-01

    Possible effects of habitat fragmentation on the population genetics of a species of wolf spider (Lycosidae) from remnant Callitris woodland in the wheat belt of central western New South Wales in Australia are examined. Single-strand conformational analysis of mitochondrial cytochrome oxidase (subunit 1) was used to characterize the haplotypes of 295 spiders in six blocks each of four woodland sites. DNA sequences were collected from 119 of these spiders to confirm haplotype scoring, allow phylogeny estimation and permit calculation of sequence-based statistics. Intra-block tests do not suggest widespread effects of fragmentation. Genetic diversity is high in all blocks, with 25 haplotypes being identified. Nucleotide diversity is relatively low, as all of the haplotypes are closely related. One block had a significantly low value for the Ewens/Watterson test of neutrality and one block's value was nearly significantly high. Two blocks had nearly significant values of the Harpending Raggedness Index testing for recent population bottlenecks. No other intrablock tests approach significance. Interpopulation comparisons show significant nonhomogeneity of haplotype frequencies globally and in all pairwise comparisons. Relationships between woodland blocks based on haplotype frequencies are discordant with geographical proximity. Haplotype distribution patterns suggest that population structuring existed prior to fragmentation. We develop two measures of genetic distinctiveness to identify subpopulations of interest for conserving evolutionary processes in a species' regional population. One is based on the sum of pairwise FST values and one on the spatial distribution of genetic variation. High values of the measure suggest a subpopulation might have been recently perturbed and low values that it is relatively undisturbed. The two measures identify different blocks as being of particular interest. PMID:12406240

  4. Cytomolecular identification of individual wheat-wheat chromosome arm associations in wheat-rye hybrids.

    PubMed

    Megyeri, M; Molnr-Lng, M; Molnr, I

    2013-01-01

    Chromosome pairing in the meiotic metaphase I of wheat-rye hybrids has been characterized by sequential genomic and fluorescent in situ hybridization allowing not only the discrimination of wheat and rye chromosomes, but also the identification of the individual wheat and rye chromosome arms involved in the chromosome associations. The majority of associations (93.8%) were observed between the wheat chromosomes. The largest number of wheat-wheat chromosome associations (53%) was detected between the A and D genomes, while the frequency of B-D and A-B associations was significantly lower (32 and 8%, respectively). Among the A-D chromosome associations, pairing between the 3AL and 3DL arms was observed with the highest frequency, while the most frequent of all the chromosome associations (0.113/cell) was found to be the 3DS-3BS. Differences in the pairing frequency of the individual chromosome arms of wheat-rye hybrids have been discussed in relation to the homoeologous relationships between the constituent genomes of hexaploid wheat. PMID:23306424

  5. Molecular, cytological and morpho-agronomical characterization of hexaploid somatic hybrids in Medicago.

    PubMed

    Pupilli, F; Businelli, S; Caceres, M E; Damiani, F; Arcioni, S

    1995-03-01

    Somatic hybrid plants produced by protoplast fusion between tetraploid Medicago sativa (2n= 4x=32) and the diploid species Medicago coerulea (2n= 2x=16) have been RFLP fingerprinted to establish their nuclear composition. Although all of the chromosomes were present, molecular analysis revealed an incomplete incorporation of the alleles of the diploid parent in the fusion products. In the polycross progeny the alleles of both parents segregated in a Mendelian mode. Cytological observations indicated that in the somatic hybrid population minor abnormalities are present; these are restricted mainly to the formation of univalents and lagging chromosomes. Meiosis appeared to be more stable than has been previously reported in the hexaploids of alfalfa. The somatic hybrids grown in the field had a rather vigorous aspect, particularly with respect to the vegetative organs. Forage yield was comparable to that of thmore productive parent. The results are discussed with a view to utilizing the somatic hybrids as starting material for breeding alfalfa at the hexaploid level. PMID:24173924

  6. Impact of the D genome and quantitative trait loci on quantitative traits in a spring durum by spring bread wheat cross

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Desirable agronomic traits are similar for common hexaploid (6X) bread wheat (Triticum aestivum, 2n = 6x = 42, genome, AABBDD) and tetraploid (4X) durum wheat (Triticum turgidum durum, 2n = 4x = 28, genome, AABB). However, they are genetically isolated from each other due to an unequal number of ge...

  7. GENETICS OF RESISTANCE TO TAN SPOT IN A RECOMBINANT INBRED POPULATION OF WHEAT.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The most efficient long-term approach to control tan spot of wheat, caused by Pyrenophora tritici-repentis, is through genetic resistance in the host. The hard red spring wheat cv. "Erik", both insensitive to Ptr ToxA and resistant to the fungus, has long been recognized as a potential source of ta...

  8. Identification of milling and baking quality QTL in multiple soft wheat mapping populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat derived food products require a range of characteristics. Identification and understanding of the genetic components controlling end-use quality of wheat is important for crop improvement. We assessed the underlying genetics controlling specific milling and baking quality parameters of soft wh...

  9. Development of genome-specific primers for homoeologous genes in allopolyploid species: the waxy and starch synthase II genes in allohexaploid wheat (Triticum aestivum L.) as examples

    PubMed Central

    2010-01-01

    Background In allopolypoid crops, homoeologous genes in different genomes exhibit a very high sequence similarity, especially in the coding regions of genes. This makes it difficult to design genome-specific primers to amplify individual genes from different genomes. Development of genome-specific primers for agronomically important genes in allopolypoid crops is very important and useful not only for the study of sequence diversity and association mapping of genes in natural populations, but also for the development of gene-based functional markers for marker-assisted breeding. Here we report on a useful approach for the development of genome-specific primers in allohexaploid wheat. Findings In the present study, three genome-specific primer sets for the waxy (Wx) genes and four genome-specific primer sets for the starch synthase II (SSII) genes were developed mainly from single nucleotide polymorphisms (SNPs) and/or insertions or deletions (Indels) in introns and intron-exon junctions. The size of a single PCR product ranged from 750 bp to 1657 bp. The total length of amplified PCR products by these genome-specific primer sets accounted for 72.6%-87.0% of the Wx genes and 59.5%-61.6% of the SSII genes. Five genome-specific primer sets for the Wx genes (one for Wx-7A, three for Wx-4A and one for Wx-7D) could distinguish the wild type wheat and partial waxy wheat lines. These genome-specific primer sets for the Wx and SSII genes produced amplifications in hexaploid wheat, cultivated durum wheat, and Aegilops tauschii accessions, but failed to generate amplification in the majority of wild diploid and tetraploid accessions. Conclusions For the first time, we report on the development of genome-specific primers from three homoeologous Wx and SSII genes covering the majority of the genes in allohexaploid wheat. These genome-specific primers are being used for the study of sequence diversity and association mapping of the three homoeologous Wx and SSII genes in natural populations of both hexaploid wheat and cultivated tetraploid wheat. The strategies used in this paper can be used to develop genome-specific primers for homoeologous genes in any allopolypoid species. They may be also suitable for (i) the development of gene-specific primers for duplicated paralogous genes in any diploid species, and (ii) the development of allele-specific primers at the same gene locus. PMID:20497560

  10. Population Subdivision of Fusarium graminearum from Barley and Wheat in the Upper Midwestern United States at the Turn of the Century.

    PubMed

    Liang, Junmin; Lofgren, Lotus; Ma, Zhanhong; Ward, Todd J; Kistler, H Corby

    2015-11-01

    Fusarium graminearum, the causal agent of Fusarium head blight (FHB) in wheat and barley, is one of the most economically destructive pathogens of these grains worldwide. Recent population genetic studies of the pathogen obtained from wheat in North America supported population subdivision in part correlated with the spectrum of trichothecene mycotoxins (chemotype) produced by individuals within each population. In contrast, a recent study of F. graminearum obtained from diseased barley in the upper Midwestern United States concluded that only a single population was present, consisting of individuals with various chemotypes. To test whether strains derived from different hosts potentially have different population dynamics, we obtained the barley strains used in the previous study and compared them with wheat strains isolated at a similar time and geographic origin. A total of 247 F. graminearum isolates from barley were assigned firmly into two clusters using a Bayesian clustering method. Subdivision within the barley population corresponded to the previously described NA1 (correlated with the 15ADON chemotype) and NA2 (correlated with the 3ADON chemotype) populations from wheat. However, in both sampling periods the barley population exhibited a higher level of genetic differentiation between NA1 and NA2 populations, fewer admixed individuals and evidence of unidirectional gene introgression (15ADON strains with NA2 genetic backgrounds). These results suggest less recombination between NA1 and NA2 populations on barley compared with wheat. The frequency of 3ADON chemotype strains in the most recently surveyed barley population suggests a latitudinal cline from the northern (49%), central (40%) to the southern (29%) sampling area. The potential to produce a novel trichothecene, 3?-acetoxy,7?,15-dihydroxy-12,13-epoxytrichothe-9-ene (NX-2), was not detected in the barley population but occurred at a low rate (2.4%) in the wheat population. PMID:26107972

  11. Seedling tolerance to Rhizoctonia and Pythium in wheat chromosome group 4 addition lines from Thinopyrum spp

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chromosome 4 from Thinopyrum spp. confers regrowth after a sexual cycle and senescence in hexaploid wheat (Triticum aestivum), and is associated with resistance to the necrotrophic eyespot pathogen, Tapesia yallundae. We sought to determine whether robust root growth or other traits expressed in ch...

  12. The effect of wheat prebiotics on the gut bacterial population and iron status of iron deficient broiler chickens

    PubMed Central

    2014-01-01

    Background Currently, there is a lot of interest in improving gut health, and consequently increasing Fe absorption, by managing the colonic microbial population. This is traditionally done by the consumption of probiotics, live microbial food supplements. However, an alternative, and often very effective approach, is the consumption of food ingredients known as prebiotics. Fructans and arabinoxylans are naturally occurring non-digestible oligosaccharides in wheat that exhibit prebiotic properties and may enhance intestinal iron (Fe) absorption. The aim of this study was to assess the effect of prebiotics from wheat on Fe bioavailability in vitro (Caco-2 cells) and in vivo (broiler chickens, Gallus gallus). Methods In the current study, the effect of intra-amniotic administration of wheat samples extracts at 17 d of embryonic incubation on the Fe status and possible changes in the bacterial population in intestinal content of broiler hatchlings were investigated. A group of 144 eggs were injected with the specified solution (1 ml per egg) into the amniotic fluid. Immediately after hatch (21 d) and from each treatment group, 10 chicks were euthanized and their small intestine, liver and cecum were removed for relative mRNA abundance of intestinal Fe related transporters, relative liver ferritin amounts and bacterial analysis of cecal content, respectively. Results The in vivo results are in agreement with the in vitro observations, showing no differences in the hatchling Fe status between the treatment groups, as Fe bioavailability was not increased in vitro and no significant differences were measured in the intestinal expression of DMT1, Ferroportin and DcytB in vivo. However, there was significant variation in relative amounts of bifidobacteria and lactobacilli in the intestinal content between the treatments groups, with generally more bifidobacteria being produced with increased prebiotic content. Conclusions In this study we showed that prebiotics naturally found in wheat grains/bread products significantly increased intestinal beneficial bacterial population in Fe deficient broiler chickens. With this short-term feeding trial we were not able to show differences in the Fe-status of broilers. Nevertheless, the increase in relative amounts of bifidobacteria and lactobacilli in the presence of wheat prebiotics is an important finding as these bacterial populations may affect Fe bioavailability in long-term studies. PMID:24924421

  13. Wheat domestication: lessons for the future.

    PubMed

    Charmet, Gilles

    2011-03-01

    Wheat was one of the first crops to be domesticated more than 10,000 years ago in the Middle East. Molecular genetics and archaeological data have allowed the reconstruction of plausible domestication scenarios leading to modern cultivars. For diploid einkorn and tetraploid durum wheat, a single domestication event has likely occurred in the Karacadag Mountains, Turkey. Following a cross between tetraploid durum and diploid T.tauschii, the resultant hexaploid bread wheat was domesticated and disseminated around the Caucasian region. These polyploidisation events facilitated wheat domestication and created genetic bottlenecks, which excluded potentially adaptive alleles. With the urgent need to accelerate genetic progress to confront the challenges of climate change and sustainable agriculture, wild ancestors and old landraces represent a reservoir of underexploited genetic diversity that may be utilized through modern breeding methods. Understanding domestication processes may thus help identifying new strategies. PMID:21377616

  14. A High-Density Genetic Map with Array-Based Markers Facilitates Structural and Quantitative Trait Locus Analyses of the Common Wheat Genome

    PubMed Central

    Iehisa, Julio Cesar Masaru; Ohno, Ryoko; Kimura, Tatsuro; Enoki, Hiroyuki; Nishimura, Satoru; Okamoto, Yuki; Nasuda, Shuhei; Takumi, Shigeo

    2014-01-01

    The large genome and allohexaploidy of common wheat have complicated construction of a high-density genetic map. Although improvements in the throughput of next-generation sequencing (NGS) technologies have made it possible to obtain a large amount of genotyping data for an entire mapping population by direct sequencing, including hexaploid wheat, a significant number of missing data points are often apparent due to the low coverage of sequencing. In the present study, a microarray-based polymorphism detection system was developed using NGS data obtained from complexity-reduced genomic DNA of two common wheat cultivars, Chinese Spring (CS) and Mironovskaya 808. After design and selection of polymorphic probes, 13,056 new markers were added to the linkage map of a recombinant inbred mapping population between CS and Mironovskaya 808. On average, 2.49 missing data points per marker were observed in the 201 recombinant inbred lines, with a maximum of 42. Around 40% of the new markers were derived from genic regions and 11% from repetitive regions. The low number of retroelements indicated that the new polymorphic markers were mainly derived from the less repetitive region of the wheat genome. Around 25% of the mapped sequences were useful for alignment with the physical map of barley. Quantitative trait locus (QTL) analyses of 14 agronomically important traits related to flowering, spikes, and seeds demonstrated that the new high-density map showed improved QTL detection, resolution, and accuracy over the original simple sequence repeat map. PMID:24972598

  15. Fine mapping a domestication-related QTL for spike-related traits in a synthetic wheat.

    PubMed

    Wang, Jin; Liao, Xiangzheng; Li, Yulian; Zhou, Ronghua; Yang, Xueju; Gao, Lifeng; Jia, Jizeng

    2010-10-01

    QTL analysis using a BC5F2:3 mapping population derived from a cross between Am3, a synthetic hexaploid wheat as a donor parent, and Laizhou953, a Chinese winter wheat cultivar as a recurrent parent, showed that variation at the microsatellite locus Xgwm113 on chromosome 4B was associated with variation in grain number per spike (GN), spike length (SL), and spikelet number per spike (SPI). The Qgn.caas-4B, Qsl.caas-4B, and Qspi.caas-4B were responsible for 16.6%-35.6%, 18.0%-32.3%, and 23.7%-25.9% of the phenotypic variation present in two environments, respectively. Segregation for GN fit a Mendelian monogenic ratio. A subpopulation consisting of 497 plants was used to map the QTL to a 1.2cM interval between Xgwm113 and Xgwm857. The three spike traits, GN, SL, and SPI, were correlated and were thus probably under the pleiotropic control of the QTL. The Am3 allele had a reduction effect on all three spike traits. Evidence for positive selective history on SSR locus Xgwm113 was supported using Ewens-Watterson's statistic test on a germplasm panel of wild and landrace entries, suggesting that this genomic region may contain genes under selection during wheat domestication. PMID:20962886

  16. Spatio-temporal genetic variation in populations of wild emmer wheat, Triticum turgidum ssp. dicoccoides, as revealed by AFLP analysis.

    PubMed

    Ozbek, O; Millet, E; Anikster, Y; Arslan, O; Feldman, M

    2007-06-01

    Genetic structure of natural populations of wild crop relatives has been the subject of many studies. Yet, most of them focused on the assessment of spatial genetic diversity, while information on long-term variation, affected by yearly changes, has been considered only in few cases. The present study aimed therefore, to estimate the spatio-temporal genetic variation in populations of wild emmer wheat, the progenitor of domesticated wheat, and to assess the contribution of spatial versus temporal factors to the maintenance of genetic variation in a population. Single spikes were collected in the years 1988 and 2002 from plants that grew in the same sampling points, from six different habitats in the Ammiad conservation site, Eastern Galilee, Israel. Seeds were planted in a nursery and DNA was extracted from each plant and analyzed by the AFLP method. Fourteen primer combinations yielded 1,545 bands of which 50.0 and 48.8% were polymorphic in the years 1988 and 2002, respectively. Genetic diversity was much larger within populations than between populations and the temporal genetic diversity was considerably smaller than the spatial one. Nevertheless, population genetic structure may vary to some degree in different years, mainly due to fluctuations in population size because of yearly rainfall variations. This may lead to predominance of different genotypes in different years. Clustering the plants by their genetic distances grouped them according to their habitats, indicating the existence of genotype-environment affinities. The significance of the results in relation to factors affecting the maintenance of polymorphism in natural populations is discussed. PMID:17447050

  17. Assessment of Allergy to Milk, Egg, Cod, and Wheat in Swedish Schoolchildren: A Population Based Cohort Study

    PubMed Central

    Winberg, Anna; West, Christina E; Strinnholm, Åsa; Nordström, Lisbeth; Hedman, Linnea; Rönmark, Eva

    2015-01-01

    Objectives Knowledge about the prevalence of allergies to foods in childhood and adolescence is incomplete. The purpose of this study was to investigate the prevalence of allergies to milk, egg, cod, and wheat using reported data, clinical examinations, and double-blind placebo-controlled food challenges, and to describe the phenotypes of reported food hypersensitivity in a cohort of Swedish schoolchildren. Methods In a population-based cohort of 12-year-old children, the parents of 2612 (96% of invited) completed a questionnaire. Specific IgE antibodies to foods were analyzed in a random sample (n=695). Children reporting complete avoidance of milk, egg, cod, or wheat due to perceived hypersensitivity and without physician-diagnosed celiac disease were invited to undergo clinical examination that included specific IgE testing, a celiac screening test, and categorization into phenotypes of food hypersensitivity according to preset criteria. Children with possible food allergy were further evaluated with double-blind challenges. Results In this cohort, the prevalence of reported food allergy to milk, egg, cod, or wheat was 4.8%. Food allergy was diagnosed in 1.4% of the children after clinical evaluation and in 0.6% following double-blind placebo-controlled food challenge. After clinical examination, children who completely avoided one or more essential foods due to perceived food hypersensitivity were categorized with the following phenotypes: allergy (29%), outgrown allergy (19%), lactose intolerance (40%), and unclear (12%). Conclusions There was a high discrepancy in the prevalence of allergy to milk, egg, cod and wheat as assessed by reported data, clinical evaluation, and double-blind food challenges. Food hypersensitivity phenotyping according to preset criteria was helpful for identifying children with food allergy. PMID:26134827

  18. Identification and validation of quantitative trait loci for grain protein concentration in adapted Canadian durum wheat populations.

    PubMed

    Suprayogi, Y; Pozniak, Curtis Jerry; Clarke, F R; Clarke, J M; Knox, R E; Singh, A K

    2009-08-01

    Grain protein concentration (GPC) is one of the most important factors influencing pasta-making quality. Durum wheat (Triticum turgidum L. var durum) cultivars with high GPC produce pasta with increased tolerance to overcooking and greater cooked firmness. However, the large environmental effect on expression of GPC and the negative correlation with grain yield have slowed genetic improvement of this important trait. Understanding the genetics and identification of molecular markers associated with high GPC would aid durum wheat breeders in trait selection at earlier generations. The objectives of this study were to identify and validate molecular markers associated with quantitative trait loci (QTL) for elevated GPC in durum wheat. A genetic map was constructed using SSR and DArT markers in an F(1)-derived doubled haploid (DH) population derived from the cross DT695 x Strongfield. The GPC data were collected from replicated trials grown in six Canadian environments from 2002 to 2005. QTL associated with variation for GPC were identified on the group 1, 2, and 7 chromosomes and on 5B and 6B, but only QGpc.usw-B3 on 2B and QGpc.usw-A3 on 7A were expressed consistently in four and six environments, respectively. Positive alleles for GPC at these loci were contributed by the high-GPC parent Strongfield. The QGpc.usw-A3 QTL was validated in a second DH population, and depending on environment, selection for the Strongfield allele at barc108 resulted in +0.4% to +1.0% increase in GPC, with little effect on yield in most environments. Given the consistent expression pattern in multiple populations and environments, barc108 could be useful for marker-assisted selection for high GPC. PMID:19462147

  19. Establishing an Efficient Way to Utilize the Drought Resistance Germplasm Population in Wheat

    PubMed Central

    Wang, Jiancheng; Guan, Yajing; Wang, Yang; Zhu, Liwei; Wang, Qitian; Hu, Qijuan; Hu, Jin

    2013-01-01

    Drought resistance breeding provides a hopeful way to improve yield and quality of wheat in arid and semiarid regions. Constructing core collection is an efficient way to evaluate and utilize drought-resistant germplasm resources in wheat. In the present research, 1,683 wheat varieties were divided into five germplasm groups (high resistant, HR; resistant, R; moderate resistant, MR; susceptible, S; and high susceptible, HS). The least distance stepwise sampling (LDSS) method was adopted to select core accessions. Six commonly used genetic distances (Euclidean distance, Euclid; Standardized Euclidean distance, Seuclid; Mahalanobis distance, Mahal; Manhattan distance, Manhat; Cosine distance, Cosine; and Correlation distance, Correlation) were used to assess genetic distances among accessions. Unweighted pair-group average (UPGMA) method was used to perform hierarchical cluster analysis. Coincidence rate of range (CR) and variable rate of coefficient of variation (VR) were adopted to evaluate the representativeness of the core collection. A method for selecting the ideal constructing strategy was suggested in the present research. A wheat core collection for the drought resistance breeding programs was constructed by the strategy selected in the present research. The principal component analysis showed that the genetic diversity was well preserved in that core collection. PMID:23737717

  20. Composition of the Fusarium graminearum species complex populations in wheat cropping environments in Southern Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Fusarium graminearum species complex (FGSC) comprises several toxigenic species that cause Fusarium head blight (FHB) in wheat. In this study, high number (n=671 isolates) of pathogenic isolates (isolated from infected spikes) was obtained from a 3-year large-scale survey (2009-2011) conducted o...

  1. Population Dynamics of the Wheat Pest, Hessian fly, in the Southeastern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hessian fly, Mayetiola destructor (Say), is a wheat crop pest in the United States creating millions of dollars of crop losses each year. The primary means of controlling this insect pest is through the use of resistant cultivars. Over the years, this practice has led to Hessian flies containing g...

  2. THE WHEAT D-GENOME HMW-GLUTENIN LOCUS:BAC SEQUENCING, GENE DISTRIBUTION, AND RETROTRANSPOSON CLUSTERS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A bacterial-artificial-chromosome (BAC) clone from the genome of Triticum tauschii, the D-genome ancestor of hexaploid bread wheat, was sequenced and the presence of the two paralogous x- and y- type high-molecular-weight (HMW) glutenin genes of the Glu-D1 locus was confirmed. These two genes occur...

  3. Exploring the diploid wheat ancestral A genome through sequence comparison at the High-Molecular-Weight glutenin locus region

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The polyploid nature of hexaploid wheat (T. aestivum, AABBDD) often represents a great challenge in various aspects of research including genetic mapping, map-based cloning of important genes, and sequencing and accurate assembly of its genome. To explore the utility of ancestral diploid species o...

  4. A multiparental cross population for mapping QTL for agronomic traits in durum wheat (Triticum turgidum ssp. durum).

    PubMed

    Milner, Sara Giulia; Maccaferri, Marco; Huang, Bevan Emma; Mantovani, Paola; Massi, Andrea; Frascaroli, Elisabetta; Tuberosa, Roberto; Salvi, Silvio

    2016-02-01

    Multiparental cross designs for mapping quantitative trait loci (QTL) provide an efficient alternative to biparental populations because of their broader genetic basis and potentially higher mapping resolution. We describe the development and deployment of a recombinant inbred line (RIL) population in durum wheat (Triticum turgidum ssp. durum) obtained by crossing four elite cultivars. A linkage map spanning 2664cM and including 7594 single nucleotide polymorphisms (SNPs) was produced by genotyping 338 RILs. QTL analysis was carried out by both interval mapping on founder haplotype probabilities and SNP bi-allelic tests for heading date and maturity date, plant height and grain yield from four field experiments. Sixteen QTL were identified across environments and detection methods, including two yield QTL on chromosomes 2BL and 7AS, with the former mapped independently from the photoperiod response gene Ppd-B1, while the latter overlapped with the vernalization locus VRN-A3. Additionally, 21 QTL with environment-specific effects were found. Our results indicated a prevalence of environment-specific QTL with relatively small effect on the control of grain yield. For all traits, functionally different QTL alleles in terms of direction and size of genetic effect were distributed among parents. We showed that QTL results based on founder haplotypes closely matched functional alleles at known heading date loci. Despite the four founders, only 2.1 different functional haplotypes were estimated per QTL, on average. This durum wheat population provides a mapping resource for detailed genetic dissection of agronomic traits in an elite background typical of breeding programmes. PMID:26132599

  5. Variation between Ethiopian and North American Barley Varieties (Hordeum vulgare) in Response to Russian Wheat Aphid (Diuraphis noxia) populations

    PubMed Central

    Araya, Alemu; Belay, Tesfay; Hussein, Temam

    2014-01-01

    The Russian wheat aphid, Diuraphis noxia (Mordvilko) (Hemiptera: Aphididae), causes severe damage to barley, Hordeum vulgare L. (Poales: Poaceae), in the highlands of Ethiopia. Little information is available on the control of this pest in Ethiopia. An experiment aimed at evaluating the resistance of barley varieties from the USA to D. noxia populations and determining biotypic variation between Ethiopian and North American D. noxia populations was conducted. The D. noxia-resistant barley varieties Burton and RWA-1758 from the USA, the resistant barley line 3296-15 from Ethiopia, and a local Ethiopian susceptible variety were included in a randomized design in a greenhouse under natural light conditions. There were highly significant differences (P < 0.001) in the mean D. noxia population, leaf chlorosis, leaf rolling, plant stunting, number of tillers per plant, and the percentage of infested tillers per plant between the resistant and susceptible varieties. The aphid population per tiller was lower on the resistant barley plants than on the susceptible plants. Severe plant damage was observed on the local barley variety, while the least damage was observed on Burton, followed by RWA-1758. Burton and RWA-1758 were therefore highly resistant and moderately resistant, respectively, to the northern Ethiopian D. noxia populations, indicating similarities in biotypes between the United States and northern Ethiopian D. noxia populations. The damage to variety 3296-15 was greater than to Burton and RWA-1758. Leaf chlorosis scores and leaf rolling scores for variety 3296-15 upon treatment with the north Ethiopian D. noxia population indicate likely biotypic variation between D. noxia populations of northern and central Ethiopia. PMID:25373187

  6. Genetic characterization of North American populations of the wheat curl mite (Aceria tosichella) and dry bulb mite (Aceria tulipae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The wheat curl mite, Aceria tosichella Keifer, transmits at least three harmful viruses, wheat streak mosaic virus (WSMV), high plains virus (HPV), and Triticum mosaic virus (TriMV) to wheat (Triticum aestivum L.) throughout the Great Plains. This virus complex is considered to be the most serious d...

  7. Association of Size Exclusion HPLC of Endosperm Proteins with Dough Mixing and Bread-making Characteristics in a Recombinant Inbred Population of Hard Red Spring Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Variation of polymeric proteins is known to affect wheat end-use quality. This research aimed to investigate the composition of polymeric proteins and their associations with dough mixing strength and bread-making characteristics in a near-homogenous population of 139 recombinant inbred lines (RILs...

  8. Effects of plant tannins supplementation on animal response and in vivo ruminal bacterial populations associated with bloat in heifers grazing wheat forage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research was conducted to determine the effects of sources of tannins on in vitro ruminal gas and foam production, in vivo ruminal bacterial populations, bloat dynamics and ADG of heifers grazing wheat forage. Two experiments were conducted to 1) enumerate the effect of tannins supplementation on bi...

  9. [Manaca, sweet potato and yam: possible substitutes of wheat in foods for two ethnic population in Venezuelan Amazon].

    PubMed

    Sangronis, Elba; Teixeira, Patricia; Otero, Mariana; Guerra, Marisa; Hidalgo, Glida

    2006-03-01

    In this study, flours from manaca or acai (Euterpe oleracea Mart), sweet potato (Ipomea batatas), and yam (Dioscorea spp.), species grown in the Venezuelan Amazon, were obtained. The proximal composition, water activity (a(w)), Fe, Ca, Zn, Mg, Cu, Na and K content were determined for the flours of manaca, sweet potato and yam. These flours were used as ingredients of products for the inhabitants of the indigenous populations of the Venezuelan Amazon (Piaroa and Hiwi). Two types of products that traditionally contain wheat flour in their formulation (ingredient they know by transculturation) were formulated; an attempt to substitute it totally or partially by the manaca, sweet potato and/or yam flours was made. For the selection of the products to be formulated, the preferences and eating habits of the indigenous communities and ease and simplicity of the preparations to be developed, were considered. The two products formulated were cookies and "small cakes". To decide on the formulation(s) of the final product(s), sensorial evaluations were made in the laboratory and in the indigenous communities Piaroa and Hiwi. High fat content (16%), dietetic fiber (59.7%) and iron (25 mg / 100 g) in manaca or acai flour were remarkable. Two types of cookies and two of "small cakes" were equally accepted by the indigenous communities. Cookies supply a high iron amount (about 24%). The feasibility of substituting the wheat flour by manaca, sweet potato and yam flour in products accepted by two ethnic populations of the Venezuelan Amazon was demonstrated. PMID:16786737

  10. In search of tetraploid wheat accessions reduced in celiac disease-related gluten epitopes.

    PubMed

    van den Broeck, Hetty; Hongbing, Chen; Lacaze, Xavier; Dusautoir, Jean-Claude; Gilissen, Ludovicus; Smulders, Marinus; van der Meer, Ingrid

    2010-11-01

    Tetraploid wheat (durum wheat) is mainly used for the preparation of pasta. As a result of breeding, thousands of tetraploid wheat varieties exist, but also tetraploid landraces are still maintained and used for local food preparations. Gluten proteins present in wheat can induce celiac disease, a T-cell mediated auto-immune disorder, in genetically predisposed individuals after ingestion. Compared to hexaploid wheat, tetraploid wheat might be reduced in T-cell stimulatory epitopes that cause celiac disease because of the absence of the D-genome. We tested gluten protein extracts from 103 tetraploid wheat accessions (obtained from the Dutch CGN genebank and from the French INRA collection) including landraces, old, modern, and domesticated accessions of various tetraploid species and subspecies from many geographic origins. Those accessions were typed for their level of T-cell stimulatory epitopes by immunoblotting with monoclonal antibodies against the ?-gliadin epitopes Glia-?9 and Glia-?20. In the first selection, we found 8 CGN and 6 INRA accessions with reduced epitope staining. Fourteen of the 57 CGN accessions turned out to be mixed with hexaploid wheat, and 5 out of the 8 selected CGN accessions were mixtures of two or more different gluten protein chemotypes. Based on single seed analysis, lines from two CGN accessions and one INRA accession were obtained with significantly reduced levels of Glia-?9 and Glia-?20 epitopes. These lines will be further tested for industrial quality and may contribute to the development of safer foods for celiac patients. PMID:20714643

  11. GENES ENCODING PLASTID ACETYL-COA CARBOXYLASE AND 3-PHOSPHOGLYCERATE KINASE OF THE TRITICUM/AEGILOPS COMPLEX AND THE EVOLUTIONARY HISTORY OF POLYPLOID WHEAT.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The classic wheat evolutionary history is one of adaptive radiation of the diploid Triticum/Aegilops species (A, S, D) , genome convergence and divergence of the tetraploid (T. turgidum AABB, and T. timopheevii AAAGG) and hexaploid (T. aestivum, AABBDD) species. The objective of this study was to a...

  12. Consumption of pesticide-treated wheat seed by a rural population in Malawi.

    PubMed

    Schier, Joshua G; Sejvar, James J; Lutterloh, Emily; Likaka, Andrew; Katsoudas, Eugenia; Karaseva, Yelena D; Tippett Barr, Beth; Redwood, Yanique; Monroe, Stephan

    2012-11-01

    An outbreak of typhoid fever in rural Malawi triggered an investigation by the Malawi Ministry of Health and the Centers for Disease Control and Prevention in July 2009. During the investigation, villagers were directly consuming washed, donated, pesticide-treated wheat seed meant for planting. The objective of this study was to evaluate the potential for pesticide exposure and health risk in the outbreak community. A sample of unwashed (1430?g) and washed (759?g) wheat seed donated for planting, but which would have been directly consumed, was tested for 365 pesticides. Results were compared with each other (percentage change), the US Environmental Protection Agency's (EPA) health guidance values and estimated daily exposures were compared with their Reference dose (RfD). Unwashed and washed seed samples contained, respectively: carboxin, 244 and 57?p.p.m.; pirimiphos methyl, 8.18 and 8.56?p.p.m.; total permethrin, 3.62 and 3.27?p.p.m.; and carbaryl, 0.057 and 0.025?p.p.m.. Percentage change calculations (unwashed to washed) were as follows: carboxin, -76.6%; pirimiphos methyl, +4.6%; total permethrin, -9.7%; and carbaryl -56.1%. Only carboxin and total permethrin concentration among washed seed samples exceeded US EPA health guidance values (285 and seven times, respectively). Adult estimated exposure scenarios (1?kg seed) exceeded the RfD for carboxin (8 ) and pirimiphos methyl (12 ). Adult villagers weighing 70?kg would have to consume 0.123, 0.082, 1.06, and 280?kg of washed seed daily to exceed the RfD for carboxin, pirimiphos methyl, permethrins, and carbaryl, respectively. Carboxin, pirimiphos methyl, permethrins, and carbaryl were detected in both unwashed and washed samples of seed. Carboxin, total permethrin, and carbaryl concentration were partially reduced by washing. Health risks from chronic exposure to carboxin and pirimiphos methyl in these amounts are unclear. The extent of this practice among food insecure communities receiving relief seeds and resultant health impact needs further study. PMID:23047320

  13. Consumption of pesticide-treated wheat seed by a rural population in Malawi

    PubMed Central

    Schier, Joshua G.; Sejvar, James J.; Lutterloh, Emily; Likaka, Andrew; Katsoudas, Eugenia; Karaseva, Yelena D.; Barr, Beth Tippett; Redwood, Yanique; Monroe, Stephan

    2015-01-01

    An outbreak of typhoid fever in rural Malawi triggered an investigation by the Malawi Ministry of Health and the Centers for Disease Control and Prevention in July 2009. During the investigation, villagers were directly consuming washed, donated, pesticide-treated wheat seed meant for planting. The objective of this study was to evaluate the potential for pesticide exposure and health risk in the outbreak community. A sample of unwashed (1430 g) and washed (759 g) wheat seed donated for planting, but which would have been directly consumed, was tested for 365 pesticides. Results were compared with each other (percentage change), the US Environmental Protection Agencys (EPA) health guidance values and estimated daily exposures were compared with their Reference dose (RfD). Unwashed and washed seed samples contained, respectively: carboxin, 244 and 57 p.p.m.; pirimiphos methyl, 8.18 and 8.56 p.p.m.; total permethrin, 3.62 and 3.27 p.p.m.; and carbaryl, 0.057 and 0.025 p.p.m.. Percentage change calculations (unwashed to washed) were as follows: carboxin, ?76.6%; pirimiphos methyl, +4.6%; total permethrin, ?9.7%; and carbaryl ?56.1%. Only carboxin and total permethrin concentration among washed seed samples exceeded US EPA health guidance values (285 and seven times, respectively). Adult estimated exposure scenarios (1 kg seed) exceeded the RfD for carboxin (8 ) and pirimiphos methyl (12 ). Adult villagers weighing 70 kg would have to consume 0.123, 0.082, 1.06, and 280 kg of washed seed daily to exceed the RfD for carboxin, pirimiphos methyl, permethrins, and carbaryl, respectively. Carboxin, pirimiphos methyl, permethrins, and carbaryl were detected in both unwashed and washed samples of seed. Carboxin, total permethrin, and carbaryl concentration were partially reduced by washing. Health risks from chronic exposure to carboxin and pirimiphos methyl in these amounts are unclear. The extent of this practice among food insecure communities receiving relief seeds and resultant health impact needs further study. PMID:23047320

  14. Reconstruction of the synthetic W9784 x Opata85 wheat reference population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reference populations are a valuable resource in genetics studies of crop species for determining marker order, marker selection, trait mapping, construction of large-insert libraries, cross-referencing marker platforms, and genome sequencing. Useful reference populations can be propagated indefinit...

  15. Heritability estimates and response to selection for Fusarium head blight resistance in segregating populations of soft red winter wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium head blight (FHB), or head scab is an economically important disease of wheat (Triticum aestivum L.). After a series of epidemics in the 1990s, a huge resistance-breeding effort was undertaken in numerous wheat producing states. Many breeders have transferred the Type II resistance to spr...

  16. Identifying quantitative trait loci (QTL) for resistance to Fusarium crown rot (Fusarium pseudograminearum) in two spring wheat populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium crown rot (FCR), caused by F. pseudograminearum and F. culmorum, reduces wheat yields in the Pacific Northwest (PNW) of the U.S. by as much as 35%. Currently there is no consistent durable resistance to FCR in PNW wheat cultivars. Significant QTL for crown rot resistance have been documente...

  17. A Novel Retrotransposon Inserted in the Dominant Vrn-B1 Allele Confers Spring Growth Habit in Tetraploid Wheat (Triticum turgidum L.)

    PubMed Central

    Chu, C.-G.; Tan, C. T.; Yu, G.-T; Zhong, S.; Xu, S. S.; Yan, L.

    2011-01-01

    Vernalization genes determine winter/spring growth habit in temperate cereals and play important roles in plant development and environmental adaptation. In wheat (Triticum L. sp.), it was previously shown that allelic variation in the vernalization gene VRN1 was due to deletions or insertions either in the promoter or in the first intron. Here, we report a novel Vrn-B1 allele that has a retrotransposon in its promoter conferring spring growth habit. The VRN-B1 gene was mapped in a doubled haploid population that segregated for winter-spring growth habit but was derived from two spring tetraploid wheat genotypes, the durum wheat (T. turgidum subsp. durum) variety ‘Lebsock’ and T. turgidum subsp. carthlicum accession PI 94749. Genetic analysis revealed that Lebsock carried the dominant Vrn-A1 and recessive vrn-B1 alleles, whereas PI 94749 had the recessive vrn-A1 and dominant Vrn-B1 alleles. The Vrn-A1 allele in Lebsock was the same as the Vrn-A1c allele previously reported in hexaploid wheat. No differences existed between the vrn-B1 and Vrn-B1 alleles, except that a 5463-bp insertion was detected in the 5′-UTR region of the Vrn-B1 allele. This insertion was a novel retrotransposon (designated as retrotrans_VRN), which was flanked by a 5-bp target site duplication and contained primer binding site and polypurine tract motifs, a 325-bp long terminal repeat, and an open reading frame encoding 1231 amino acids. The insertion of retrotrans_VRN resulted in expression of Vrn-B1 without vernalization. Retrotrans_VRN is prevalent among T. turgidum subsp. carthlicum accessions, less prevalent among T. turgidum subsp. dicoccum accessions, and rarely found in other tetraploid wheat subspecies. PMID:22384375

  18. High resolution melting analysis for the detection of EMS induced mutations in wheat SbeIIa genes

    PubMed Central

    2011-01-01

    Background Manipulation of the amylose-amylopectin ratio in cereal starch has been identified as a major target for the production of starches with novel functional properties. In wheat, silencing of starch branching enzyme genes by a transgenic approach reportedly caused an increase of amylose content up to 70% of total starch, exhibiting novel and interesting nutritional characteristics. In this work, the functionality of starch branching enzyme IIa (SBEIIa) has been targeted in bread wheat by TILLING. An EMS-mutagenised wheat population has been screened using High Resolution Melting of PCR products to identify functional SNPs in the three homoeologous genes encoding the target enzyme in the hexaploid genome. Results This analysis resulted in the identification of 56, 14 and 53 new allelic variants respectively for SBEIIa-A, SBEIIa-B and SBEIIa-D. The effects of the mutations on protein structure and functionality were evaluated by a bioinformatic approach. Two putative null alleles containing non-sense or splice site mutations were identified for each of the three homoeologous SBEIIa genes; qRT-PCR analysis showed a significant decrease of their gene expression and resulted in increased amylose content. Pyramiding of different single null homoeologous allowed to isolate double null mutants showing an increase of amylose content up to 21% compared to the control. Conclusion TILLING has successfully been used to generate novel alleles for SBEIIa genes known to control amylose content in wheat. Single and double null SBEIIa genotypes have been found to show a significant increase in amylose content. PMID:22074448

  19. Pennisetum squamulatum: is the predominant cytotype hexaploid or octaploid?

    PubMed

    Akiyama, Yukio; Goel, Shailendra; Chen, Zhenbang; Hanna, Wayne W; Ozias-Akins, Peggy

    2006-01-01

    Apomixis is a mode of asexual reproduction where maternal clones are produced through seeds. Consequently, genetic segregation is prevented in hybrid progenies. Pennisetum squamulatum has been used to transfer apomixis into the related sexual species Pennisetum glaucum by the introgression of an apospory-specific genomic region (ASGR)-carrier chromosome. Crosses between P. glaucum and P. squamulatum or Pennisetum purpureum have been relatively easy to make even though P. squamulatum has been reported to have a different basic chromosome number than the other 2 species (9 vs. 7) and to be hexaploid (2n = 6x = 54). Our extensive examination of one accession had shown a chromosome number of 2n = 56. In order to determine if there was a variation among accessions, we counted the number of chromosomes in 5 accessions of P. squamulatum using centromeric and 18S-5.8S-26S rDNA probes as molecular cytological markers. Our results showed that P. squamulatum is most likely octaploid with a basic chromosome number of 7 (2n = 8x = 56) and may belong to the secondary gene pool of Pennisetum. Moreover, a morphologically similar ASGR-carrier chromosome that confers apomixis was observed in all accessions. PMID:16793863

  20. A polyphasic approach to study the dynamics of microbial population of an organic wheat sourdough during its conversion to gluten-free sourdough.

    PubMed

    Lhomme, Emilie; Mezaize, Sandra; Ducasse, Maren Bonnand; Chiron, Hubert; Champomier-Vergès, Marie-Christine; Chaillou, Stéphane; Zagorec, Monique; Dousset, Xavier; Onno, Bernard

    2014-03-01

    To develop a method for organic gluten-free (GF) sourdough bread production, a long-term and original wheat sourdough was refreshed with GF flours. The dynamics of the sourdough microbiota during five months of back-slopping were analyzed by classical enumeration and molecular methods, including PCR-temporal temperature gel electrophoresis (PCR-TTGE), multiplex PCR, and pulsed field gel electrophoresis (PFGE). The results showed that the yeast counts remained constant, although Saccharomyces cerevisiae, present in the initial wheat sourdough, was no longer detected in the GF sourdough, while lactic acid bacteria (LAB) counts increased consistently. In the first phase, which was aimed at obtaining a GF sourdough from wheat sourdough, Lactobacillus sanfranciscensis, L. plantarum, and L. spicheri were the main LAB species detected. During the second phase, aimed at maintaining the GF sourdough, the L. plantarum and L. spicheri populations decreased whereas L. sanfranciscensis persisted and L. sakei became the predominant species. Multiplex PCRs also revealed the presence of several L. sakei strains in the GF sourdough. In a search for the origin of the LAB species, PCR-TTGE was performed on the flour samples but only L. sanfranciscensis was detected, suggesting a flour origin for this typical sourdough species. Thus, while replacement of the wheat flour by GF flour influenced the sourdough microbiota, some of the original sourdough LAB and yeast species remained in the GF sourdough. PMID:25296441

  1. Population-Specific Patterns of Linkage Disequilibrium and SNP Variation in Spring and Winter Polyploid Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Single nucleotide polymorphisms (SNPs) are ideally suited for the construction of high-resolution genetic maps, studying population evolutionary history and performing genome-wide association mapping experiments. Here we used a genome-wide set of 1536 SNPs to study linkage disequilibrium (LD) and po...

  2. Distribution and habitat segregation on different spatial scales among diploid, tetraploid and hexaploid cytotypes of Senecio carniolicus (Asteraceae) in the Eastern Alps

    PubMed Central

    Sonnleitner, Michaela; Flatscher, Ruth; Escobar García, Pedro; Rauchová, Jana; Suda, Jan; Schneeweiss, Gerald M.; Hülber, Karl; Schönswetter, Peter

    2010-01-01

    Background and Aims The spatial distribution of cytotypes can provide valuable insights into evolutionary patterns of polyploid complexes. In a previous study the macro-scale distribution of the three main cytotypes in Senecio carniolicus (Asteraceae) within the Eastern Alps was characterized. Employing a roughly 12-fold extended sampling, the present study focuses on unravelling patterns of cytotype distribution on the meso- and microscale and on correlating those with ecological properties of the growing sites. Methods DAPI flow cytometry of dried samples was used to determine DNA ploidy level in 5033 individuals from 100 populations spread over the entire Eastern Alpine distribution area of S. carniolicus. Descriptors of microhabitats as well as spatial data were recorded in the field, and analysed with a mixed-effects ANOVA. Key Results Extensive variation in DNA ploidy levels (2x, 3x, 4x, 5x, 6x, 7x, 8x, 9x) was detected. Of the main cytotypes, diploids and hexaploids were widespread and had strongly overlapping distributions resulting in the frequent occurrence of cytotype mixtures (half of the investigated populations), whereas tetraploids were disjunctly distributed and occurred in the south-west and the east of the species' distribution area. In spite of the frequent co-occurrence of cytotypes, only 1 % of the samples belonged to secondary cytotypes (3x, 5x, 7x, 8x, 9x). Diploids, tetraploids and hexaploids were altitudinally segregated, but with broad overlap. Similarly, highly significant differences in vegetation and rock cover as well as microhabitat exposure were found between the main cytotypes. Conclusions Senecio carniolicus shows a remarkable diversity of cytotypes. The distribution of the three main cytotypes (2x, 4x, 6x) has been shaped by Pleistocene glaciations to different extents. Whereas tetraploids are nearly entirely restricted to refugia, hexaploids colonized areas that were extensively glaciated. Diploid and hexaploid individuals often co-occur in mixed populations, where they are spatially and ecologically segregated at both the meso-scale (altitudinal differentiation, exposure of the growing site) and the micro-scale (cover of vegetation and bare rock). With regard to the ecological parameters investigated, the tetraploid cytotype occupies an intermediate position. The rareness of secondary cytotypes suggests the presence of strong pre- or post-zygotic mating barriers. PMID:20880930

  3. Construction and Characterization of Three Wheat Bacterial Artificial Chromosome Libraries

    PubMed Central

    Cao, Wenjin; Fu, Bisheng; Wu, Kun; Li, Na; Zhou, Yan; Gao, Zhongxia; Lin, Musen; Li, Guoqiang; Wu, Xinyi; Ma, Zhengqiang; Jia, Haiyan

    2014-01-01

    We have constructed three bacterial artificial chromosome (BAC) libraries of wheat cultivar Triticum aestivum Wangshuibai, germplasms T. monococcum TA2026 and TA2033. A total of 1,233,792,170,880 and 263,040 clones were picked and arrayed in 384-well plates. On the basis of genome sizes of 16.8 Gb for hexaploid wheat and 5.6 Gb for diploid wheat, the three libraries represented 9.05-, 2.60-, and 3.71-fold coverage of the haploid genomes, respectively. An improved descending pooling system for BAC libraries screening was established. This improved strategy can save 80% of the time and 68% of polymerase chain reaction (PCR) with the same successful rate as the universal 6D pooling strategy. PMID:25464379

  4. Heat and drought adaptive QTL in a wheat population designed to minimize confounding agronomic effects

    PubMed Central

    Pinto, R. Suzuky; Mathews, Ky L.; McIntyre, C. Lynne; Olivares-Villegas, Juan-Jose; Chapman, Scott C.

    2010-01-01

    A restricted range in height and phenology of the elite Seri/Babax recombinant inbred line (RIL) population makes it ideal for physiological and genetic studies. Previous research has shown differential expression for yield under water deficit associated with canopy temperature (CT). In the current study, 167 RILs plus parents were phenotyped under drought (DRT), hot irrigated (HOT), and temperate irrigated (IRR) environments to identify the genomic regions associated with stress-adaptive traits. In total, 104 QTL were identified across a combination of 115 traitsנ3 environmentsנ2years, of which 14, 16, and 10 QTL were associated exclusively with DRT, HOT, and IRR, respectively. Six genomic regions were related to a large number of traits, namely 1B-a, 2B-a, 3B-b, 4A-a, 4A-b, and 5A-a. A yield QTL located on 4A-a explained 27 and 17% of variation under drought and heat stress, respectively. At the same location, a QTL explained 28% of the variation in CT under heat, while 14% of CT variation under drought was explained by a QTL on 3B-b. The T1BL.1RS (rye) translocation donated by the Seri parent was associated with decreased yield in this population. There was no co-location of consistent yield and phenology or height-related QTL, highlighting the utility of using a population with a restricted range in anthesis to facilitate QTL studies. Common QTL for drought and heat stress traits were identified on 1B-a, 2B-a, 3B-b, 4A-a, 4B-b, and 7A-a confirming their generic value across stresses. Yield QTL were shown to be associated with components of other traits, supporting the prospects for dissecting crop performance into its physiological and genetic components in order to facilitate a more strategic approach to breeding. Electronic supplementary material The online version of this article (doi:10.1007/s00122-010-1351-4) contains supplementary material, which is available to authorized users. PMID:20523964

  5. Synthesis of trigeneric hybrids of hexaploid wheat with diploid wheatgrasses: Specificity of chromosome pairing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wild grasses in the tribe Triticeae are excellent sources of genes for superior traits, including resistance to various diseases. Diploid wheatgrasses Lophopyrum elongatum (Host) . Lve (2n = 2x = 14; EE genome) and Thinopyrum bessarabicum (Savul. & Rayss) . Lve (2n = 2x = 14; JJ genome) are...

  6. Starch waxiness in hexaploid wheat (Triticum aestivum L.) by NIR reflectance spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch, the primary energy storage component of plants, consists of two large macromolecules, amylose and amylopectin. Each molecule is composed of long chains of alpha-D-glucopyranosyl units, with branching present in amylopectin and absent in amylose. The relative abundance of these two molecules ...

  7. Isolation of full-length candidate CBF genes from hexaploid wheat (Triticum aestivum L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cold temperature is a serious abiotic stress to cereals in areas with severe winters. CBF (C-repeat binding factor) is a transcription factor that regulates Cold regulated (COR) genes in Arabidopsis and it is an important component of the CBF cold acclimation pathway. The CBF gene family is hypothes...

  8. Major genes for Na+ exclusion, Nax1 and Nax2 (wheat HKT1;4 and HKT1;5), decrease Na+ accumulation in bread wheat leaves under saline and waterlogged conditions.

    PubMed

    James, Richard A; Blake, Carol; Byrt, Caitlin S; Munns, Rana

    2011-05-01

    Two major genes for Na(+) exclusion in durum wheat, Nax1 and Nax2, that were previously identified as the Na(+) transporters TmHKT1;4-A2 and TmHKT1;5-A, were transferred into bread wheat in order to increase its capacity to restrict the accumulation of Na(+) in leaves. The genes were crossed from tetraploid durum wheat (Triticum turgidum ssp. durum) into hexaploid bread wheat (Triticum aestivum) by interspecific crossing and marker-assisted selection for hexaploid plants containing one or both genes. Nax1 decreased the leaf blade Na(+) concentration by 50%, Nax2 decreased it by 30%, and both genes together decreased it by 60%. The signature phenotype of Nax1, the retention of Na(+) in leaf sheaths resulting in a high Na(+) sheath:blade ratio, was found in the Nax1 lines. This conferred an extra advantage under a combination of waterlogged and saline conditions. The effect of Nax2 on lowering the Na(+) concentration in bread wheat was surprising as this gene is very similar to the TaHKT1;5-D Na(+) transporter already present in bread wheat, putatively at the Kna1 locus. The results indicate that both Nax genes have the potential to improve the salt tolerance of bread wheat. PMID:21357768

  9. Taxonomic Structure and Monitoring of the Dominant Population of Lactic Acid Bacteria during Wheat Flour Sourdough Type I Propagation Using Lactobacillus sanfranciscensis Starters?

    PubMed Central

    Siragusa, Sonya; Di Cagno, Raffaella; Ercolini, Danilo; Minervini, Fabio; Gobbetti, Marco; De Angelis, Maria

    2009-01-01

    The structure and stability of the dominant lactic acid bacterium population were assessed during wheat flour sourdough type I propagation by using singly nine strains of Lactobacillus sanfranciscensis. Under back-slopping propagation with wheat flour type 0 F114, cell numbers of presumptive lactic acid bacteria varied slightly between and within starters. As determined by randomly amplified polymorphic DNA-PCR and restriction endonuclease analysis-pulsed-field gel electrophoresis analyses, only three (LS8, LS14, and LS44) starters dominated throughout 10 days of propagation. The others progressively decreased to less than 3 log CFU g?1. Partial sequence analysis of the 16S rRNA and recA genes and PCR-denaturating gradient gel electrophoresis analysis using the rpoB gene allowed identification of Weissella confusa, Lactobacillus sanfranciscensis, Lactobacillus plantarum, Lactobacillus rossiae, Lactobacillus brevis, Lactococcus lactis subsp. lactis, Pediococcus pentosaceus, and Lactobacillus spp. as the dominant species of the raw wheat flour. At the end of propagation, one autochthonous strain of L. sanfranciscensis was found in all the sourdoughs. Except for L. brevis, strains of the above species were variously found in the mature sourdoughs. Persistent starters were found in association with other biotypes of L. sanfranciscensis and with W. confusa or L. plantarum. Sourdoughs were characterized for acidification, quotient of fermentation, free amino acids, and community-level catabolic profiles by USING Biolog 96-well Eco microplates. In particular, catabolic profiles of sourdoughs containing persistent starters behaved similarly and were clearly differentiated from the others. The three persistent starters were further used for the production of sourdoughs and propagated by using another wheat flour whose lactic acid bacterium population in part differed from the previous one. Also, in this case all three starter strains persisted during propagation. PMID:19088320

  10. Population structure within lineages of Wheat streak mosaic virus derived from a common founding event exhibits stochastic variation inconsistent with the deterministic quasi-species model

    SciTech Connect

    French, Roy; Stenger, Drake C. . E-mail: dstenger@unlnotes.unl.edu

    2005-12-20

    Structure of Wheat streak mosaic virus (WSMV) populations derived from a common founding event and subjected to serial passage at high multiplicity of infection (MOI) was evaluated. The founding population was generated by limiting dilution inoculation. Lineages of known pedigree were sampled at passage 9 (two populations) and at passage 15, with (three populations) or without mixing (four populations) of lineages at passage 10. Polymorphism within each population was assessed by sequencing 17-21 clones containing a 1371 nt region (WSMV-Sidney 81 nts 8001-9371) encompassing the entire coat protein cistron and flanking regions. Mutation frequency averaged {approx}5.0 x 10{sup -4}/nt across all populations and ranged from 2.4 to 11.6 x 10{sup -4}/nt within populations, but did not consistently increase or decrease with the number of passages removed from the founding population. Shared substitutions (19 nonsynonymous, 10 synonymous, and 3 noncoding) occurred at 32 sites among 44 haplotypes. Only four substitutions became fixed (frequency = 100%) within a population and nearly one third (10/32) never achieved a frequency of 10% or greater in any sampled population. Shared substitutions were randomly distributed with respect to genome position, with transitions outnumbering transversions 5.4:1 and a clear bias for A to G and U to C substitutions. Haplotype composition of each population was unique with complexity of each population varying unpredictably, in that the number and frequency of haplotypes within a lineage were not correlated with number of passages removed from the founding population or whether the population was derived from a single or mixed lineage. The simplest explanation is that plant virus lineages, even those propagated at high MOI, are subject to frequent, narrow genetic bottlenecks during systemic movement that result in low effective population size and stochastic changes in population structure upon serial passage.

  11. Evolution of the Oat Genetic Road Map: From Tetraploid to Hexaploid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development of a genetic linkage map for hexaploid oat (Avena sativa L. 2n = 6 x = 42) that defines all 21 chromosomes has been hindered due to the lack of oat-based markers and the size and complexity of the oat genome. Recent efforts in oat DArT, SSR, and SNP marker development should improve...

  12. Development of high amylose wheat through TILLING

    PubMed Central

    2012-01-01

    Background Wheat (Triticum spp.) is an important source of food worldwide and the focus of considerable efforts to identify new combinations of genetic diversity for crop improvement. In particular, wheat starch composition is a major target for changes that could benefit human health. Starches with increased levels of amylose are of interest because of the correlation between higher amylose content and elevated levels of resistant starch, which has been shown to have beneficial effects on health for combating obesity and diabetes. TILLING (Targeting Induced Local Lesions in Genomes) is a means to identify novel genetic variation without the need for direct selection of phenotypes. Results Using TILLING to identify novel genetic variation in each of the A and B genomes in tetraploid durum wheat and the A, B and D genomes in hexaploid bread wheat, we have identified mutations in the form of single nucleotide polymorphisms (SNPs) in starch branching enzyme IIa genes (SBEIIa). Combining these new alleles of SBEIIa through breeding resulted in the development of high amylose durum and bread wheat varieties containing 47-55% amylose and having elevated resistant starch levels compared to wild-type wheat. High amylose lines also had reduced expression of SBEIIa RNA, changes in starch granule morphology and altered starch granule protein profiles as evaluated by mass spectrometry. Conclusions We report the use of TILLING to develop new traits in crops with complex genomes without the use of transgenic modifications. Combined mutations in SBEIIa in durum and bread wheat varieties resulted in lines with significantly increased amylose and resistant starch contents. PMID:22584013

  13. Delineating the role of polyphenol oxidase in the darkening of alkaline wheat noodles.

    PubMed

    Fuerst, E Patrick; Anderson, James V; Morris, Craig F

    2006-03-22

    This study evaluated the effects of inhibitors on polyphenol oxidase (PPO) activity, the effect of the PPO inhibitor tropolone on noodle darkening, and the correlation of PPO activity with darkening of alkaline noodles. The PPO inhibitors tropolone and salicylhydroxamic acid (each at 1 microM) reduced kernel PPO activity by approximately 50% in three hexaploid wheat cultivars but did not inhibit PPO activity in the two very low PPO cultivars, durum Langdon, and the synthetic hexaploid-derived ID580. Tropolone (100 microg/g flour) inhibited alkaline noodle darkening (deltaL*) by 13-25% in the low PPO wheat cultivar, ID377s, and by 39-54% in the high PPO wheat cultivar, Klasic. Alkaline noodle darkening among 502 wheat samples was correlated with kernel PPO activity (r = 0.64). Results substantiate the hypothesis that PPO plays a major role in darkening of alkaline noodles. However, results also indicate that substantial darkening would occur even at zero PPO activity, as measured in the kernel PPO assay. Therefore, darkening of alkaline noodles is probably due to the cultivar-specific level of PPO activity and the presence of at least one additional darkening mechanism. Further investigation is required to identify the phenolic discoloration agent(s) and to determine the potential roles of non-PPO discoloration mechanisms, both enzymatic and nonenzymatic, in wheat products. PMID:16536622

  14. [Identification of the 1RS-7DS.7DL wheat-rye small segment translocation lines].

    PubMed

    Jun, Li; Xinguo, Zhu; Hongshen, Wan; Qin, Wang; Zongxiang, Tang; Shulan, Fu; Zujun, Yang; Manyu, Yang; Wuyun, Yang

    2015-06-01

    Rye (Secale cereale L., RR) is a valuable genetic resource for the improvement of common wheat (Triticum aestivum L., AABBDD). Transferring alien rye genes into wheat by distant hybridization and automatic chromosome doubling is an important and efficient method to boost agronomic traits, disease resistance and widening the gene pool in wheat. In this study, an octoploid triticale CD-13 (AABBDDRR) was obtained via automatic chromosome doubling by crossing landrace Penganbaimaizi (T. aestivum L., AABBDD) and rye "Qinling rye" (S. cereale cv. Qinling, RR). GISH and FISH analyses indicated that CD-13 contained a 1RS-7DS.7DL wheat-rye small segment translocation chromosome. In order to transfer the 1RS-7DS small segment translocation into hexaploid wheat, 58 lines of the F5 inbred population from the cross CD-13 x Chuanmai 42 were screened for rye chromosome segments by GISH and FISH analyses. The results showed that 13 lines contained the 1RS-7DS.7DL small segment translocation chromosome by reciprocal translocation between 1RS and 7DS. These translocation lines carrying 1RS small rye alien segment were tested for the translocation breakpoints and the presence of a storage protein locus Sec-1. The Sec-1 locus was absent in the line 811, a stable 1RS-7DS.7DL small segment translocation line. The translocation breakpoint of 1RS-7DS.7DL of this line was located in the interval of IB267-IAG95 around the telomere of 1RS chromosome. Thousand-kernel weight of the line 811 was much higher than the parent CD-13, but not significantly different from Chuanmai 42. This indicated that 1RS-7DS.7DL small segment translocation had no negative effect on thousand-kernel weight in the genetic background of Chuanmai 42. The line with 1RS-7DS.7DL translocation chromosomes can be used as a new genetic material for further studies of valuable genes and their genetic effect on 1RS small segment. PMID:26351056

  15. Confirmation of Three Quantitative Trait Loci Conferring Adult Plant Resistance to Powdery Mildew in Two Winter Wheat Populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hypersensitive, race specific genes primarily have been deployed to control powdery mildew (caused by Blumeria graminis) in wheat (Triticum aestivum); however, recent efforts have shifted to breeding for more durable resistance. Previously, three QTL for adult plant resistance (APR) to powdery milde...

  16. DEVELOPMENT OF A SAMPLING PLAN IN WINTER WHEAT THAT ESTIMATES CEREAL APHID PARASITISM LEVELS AND PREDICTS POPULATION SUPPRESSION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    From 1998 to 2001, the relationship between the proportion of cereal aphids parasitized (Pp) and the proportion of tillers with > 0 mummified aphids (Ptm) was estimated on 57 occasions in fields of hard red winter wheat located in central and western Oklahoma. Both original (57 fields) and validati...

  17. Anthesis date mainly explained correlations between post-anthesis leaf senescence, grain yield, and grain protein concentration in a winter wheat population segregating for flowering time QTLs.

    PubMed

    Bogard, Matthieu; Jourdan, Matthieu; Allard, Vincent; Martre, Pierre; Perretant, Marie Reine; Ravel, Catherine; Heumez, Emmanuel; Orford, Simon; Snape, John; Griffiths, Simon; Gaju, Oorbessy; Foulkes, John; Le Gouis, Jacques

    2011-06-01

    The genetic variability of the duration of leaf senescence during grain filling has been shown to affect both carbon and nitrogen acquisition. In particular, maintaining green leaves during grain filling possibly leads to increased grain yield, but its associated effect on grain protein concentration has not been studied. The aim of this study was to dissect the genetic factors contributing to correlations observed at the phenotypic level between leaf senescence during grain filling, grain protein concentration, and grain yield in winter wheat. With this aim in view, an analysis of quantitative trait locus (QTL) co-locations for these traits was carried out on a doubled haploid mapping population grown in a large multienvironment trial network. Pleiotropic QTLs affecting leaf senescence and grain yield and/or grain protein concentration were identified on chromosomes 2D, 2A, and 7D. These were associated with QTLs for anthesis date, showing that the phenotypic correlations with leaf senescence were mainly explained by flowering time in this wheat population. Study of the allelic effects of these pleiotropic QTLs showed that delaying leaf senescence was associated with increased grain yield or grain protein concentration depending on the environments considered. It is proposed that this differential effect of delaying leaf senescence on grain yield and grain protein concentration might be related to the nitrogen availability during the post-anthesis period. It is concluded that the benefit of using leaf senescence as a selection criterion to improve grain protein concentration in wheat cultivars may be limited and would largely depend on the targeted environments, particularly on their nitrogen availability during the post-anthesis period. PMID:21414962

  18. Genome-wide quantitative trait locus mapping identifies multiple major loci for brittle rachis and threshability in Tibetan semi-wild wheat (Triticum aestivum ssp. tibetanum Shao).

    PubMed

    Jiang, Yun-Feng; Lan, Xiu-Jin; Luo, Wei; Kong, Xing-Chen; Qi, Peng-Fei; Wang, Ji-Rui; Wei, Yu-Ming; Jiang, Qian-Tao; Liu, Ya-Xi; Peng, Yuan-Ying; Chen, Guo-Yue; Dai, Shou-Fen; Zheng, You-Liang

    2014-01-01

    Tibetan semi-wild wheat (Triticum aestivum ssp. tibetanum Shao) is a semi-wild hexaploid wheat resource that is only naturally distributed in the Qinghai-Tibet Plateau. Brittle rachis and hard threshing are two important characters of Tibetan semi-wild wheat. A whole-genome linkage map of T. aestivum ssp. tibetanum was constructed using a recombinant inbred line population (Q1028ZM9023) with 186 lines, 564 diversity array technology markers, and 117 simple sequence repeat markers. Phenotypic data on brittle rachis and threshability, as two quantitative traits, were evaluated on the basis of the number of average spike rachis fragments per spike and percent threshability in 2012 and 2013, respectively. Quantitative trait locus (QTL) mapping performed using inclusive composite interval mapping analysis clearly identified four QTLs for brittle rachis and three QTLs for threshability. However, three loci on 2DS, 2DL, and 5AL showed pleiotropism for brittle rachis and threshability; they respectively explained 5.3%, 18.6%, and 18.6% of phenotypic variation for brittle rachis and 17.4%, 13.2%, and 35.2% of phenotypic variation for threshability. A locus on 3DS showed an independent effect on brittle rachis, which explained 38.7% of the phenotypic variation. The loci on 2DS and 3DS probably represented the effect of Tg and Br1, respectively. The locus on 5AL was in very close proximity to the Q gene, but was different from the predicted q in Tibetan semi-wild wheat. To our knowledge, the locus on 2DL has never been reported in common wheat but was prominent in T. aestivum ssp. tibetanum accession Q1028. It remarkably interacted with the locus on 5AL to affect brittle rachis. Several major loci for brittle rachis and threshability were identified in Tibetan semi-wild wheat, improving the understanding of these two characters and suggesting the occurrence of special evolution in Tibetan semi-wild wheat. PMID:25474652

  19. On-farm dynamic management of genetic diversity: the impact of seed diffusions and seed saving practices on a population-variety of bread wheat

    PubMed Central

    Thomas, Mathieu; Demeulenaere, Elise; Dawson, Julie C; Khan, Abdul Rehman; Galic, Nathalie; Jouanne-Pin, Sophie; Remoue, Carine; Bonneuil, Christophe; Goldringer, Isabelle

    2012-01-01

    Since the domestication of crop species, humans have derived specific varieties for particular uses and shaped the genetic diversity of these varieties. Here, using an interdisciplinary approach combining ethnobotany and population genetics, we document the within-variety genetic structure of a population-variety of bread wheat (Triticum aestivum L.) in relation to farmers practices to decipher their contribution to crop species evolution. Using 19 microsatellites markers, we conducted two complementary graph theory-based methods to analyze population structure and gene flow among 19 sub-populations of a single population-variety [Rouge de Bordeaux (RDB)]. The ethnobotany approach allowed us to determine the RDB history including diffusion and reproduction events. We found that the complex genetic structure among the RDB sub-populations is highly consistent with the structure of the seed diffusion and reproduction network drawn based on the ethnobotanical study. This structure highlighted the key role of the farmer-led seed diffusion through founder effects, selection and genetic drift because of human practices. An important result is that the genetic diversity conserved on farm is complementary to that found in the genebank indicating that both systems are required for a more efficient crop diversity conservation. PMID:23346224

  20. Effect of hosts on competition among clones and evidence of differential selection between pathogenic and saprophytic phases in experimental populations of the wheat pathogen Phaeosphaeria nodorum

    PubMed Central

    2011-01-01

    Background Monoculture, multi-cropping and wider use of highly resistant cultivars have been proposed as mechanisms to explain the elevated rate of evolution of plant pathogens in agricultural ecosystems. We used a mark-release-recapture experiment with the wheat pathogen Phaeosphaeria nodorum to evaluate the impact of two of these mechanisms on the evolution of a pathogen population. Nine P. nodorum isolates marked with ten microsatellite markers and one minisatellite were released onto five replicated host populations to initiate epidemics of Stagonospora nodorum leaf blotch. The experiment was carried out over two consecutive host growing seasons and two pathogen collections were made during each season. Results A total of 637 pathogen isolates matching the marked inoculants were recovered from inoculated plots over two years. Genetic diversity in the host populations affected the evolution of the corresponding P. nodorum populations. In the cultivar mixture the relative frequencies of inoculants did not change over the course of the experiment and the pathogen exhibited a low variation in selection coefficients. Conclusions Our results support the hypothesis that increasing genetic heterogeneity in host populations may retard the rate of evolution in associated pathogen populations. Our experiment also provides indirect evidence of fitness costs associated with host specialization in P. nodorum as indicated by differential selection during the pathogenic and saprophytic phases. PMID:21718545

  1. Structural and functional partitioning of bread wheat chromosome 3B.

    PubMed

    Choulet, Frédéric; Alberti, Adriana; Theil, Sébastien; Glover, Natasha; Barbe, Valérie; Daron, Josquin; Pingault, Lise; Sourdille, Pierre; Couloux, Arnaud; Paux, Etienne; Leroy, Philippe; Mangenot, Sophie; Guilhot, Nicolas; Le Gouis, Jacques; Balfourier, Francois; Alaux, Michael; Jamilloux, Véronique; Poulain, Julie; Durand, Céline; Bellec, Arnaud; Gaspin, Christine; Safar, Jan; Dolezel, Jaroslav; Rogers, Jane; Vandepoele, Klaas; Aury, Jean-Marc; Mayer, Klaus; Berges, Hélène; Quesneville, Hadi; Wincker, Patrick; Feuillet, Catherine

    2014-07-18

    We produced a reference sequence of the 1-gigabase chromosome 3B of hexaploid bread wheat. By sequencing 8452 bacterial artificial chromosomes in pools, we assembled a sequence of 774 megabases carrying 5326 protein-coding genes, 1938 pseudogenes, and 85% of transposable elements. The distribution of structural and functional features along the chromosome revealed partitioning correlated with meiotic recombination. Comparative analyses indicated high wheat-specific inter- and intrachromosomal gene duplication activities that are potential sources of variability for adaption. In addition to providing a better understanding of the organization, function, and evolution of a large and polyploid genome, the availability of a high-quality sequence anchored to genetic maps will accelerate the identification of genes underlying important agronomic traits. PMID:25035497

  2. [Specific phenotypic and genotypic features of an ultradwarf hexaploid triticale form].

    PubMed

    Kurkiev, K U

    2008-03-01

    A new dwarf form (15-25 cm) of hexaploid triticale differing in its morphology from all the accessions of the world collection was studied. Analysis of the F1-F3 hybrids between this triticale form and the triticale with common morphology has demonstrated that the dwarfism is determined by one gene with an incomplete dominance, which influences several morphological traits (internode length, leaf structure, and spike length, density, and color). The presence of this gene partially or completely inhib. PMID:18664144

  3. QTL for root angle and number in a population developed from bread wheats (Triticum aestivum) with contrasting adaptation to water-limited environments.

    PubMed

    Christopher, Jack; Christopher, Mandy; Jennings, Raeleen; Jones, Shirley; Fletcher, Susan; Borrell, Andrew; Manschadi, Ahmad M; Jordan, David; Mace, Emma; Hammer, Graeme

    2013-06-01

    Root architecture traits in wheat are important in deep soil moisture acquisition and may be used to improve adaptation to water-limited environments. The genetic architecture of two root traits, seminal root angle and seminal root number, were investigated using a doubled haploid population derived from SeriM82 and Hartog. Multiple novel quantitative trait loci (QTL) were identified, each one having a modest effect. For seminal root angle, four QTL (-log10(P) >3) were identified on 2A, 3D, 6A and 6B, and two suggestive QTL (-log10(P) >2) on 5D and 6B. For root number, two QTL were identified on 4A and 6A with four suggestive QTL on 1B, 3A, 3B and 4A. QTL for root angle and root number did not co-locate. Transgressive segregation was found for both traits. Known major height and phenology loci appear to have little effect on root angle and number. Presence or absence of the T1BL.1RS translocation did not significantly influence root angle. Broad sense heritability (h (2)) was estimated as 50 % for root angle and 31 % for root number. Root angle QTL were found to be segregating between wheat cultivars adapted to the target production region indicating potential to select for root angle in breeding programs. PMID:23525632

  4. Genomics as the key to unlocking the polyploid potential of wheat.

    PubMed

    Borrill, Philippa; Adamski, Nikolai; Uauy, Cristobal

    2015-12-01

    1008 I. 1008 II. 1010 III. 1012 IV. 1013 V. 1014 VI. 1017 VII. 1019 1019 References 1019 SUMMARY: Polyploidy has played a central role in plant genome evolution and in the formation of new species such as tetraploid pasta wheat and hexaploid bread wheat. Until recently, the high sequence conservation between homoeologous genes, together with the large genome size ofpolyploid wheat, had hindered genomic analyses in this important crop species. In the past 5yr, however, the advent of next-generation sequencing has radically changed the wheat genomics landscape. Here, we review a series of advances in genomic resources and tools for functional genomics that are shifting the paradigm of what is possible in wheat molecular genetics and breeding. We discuss how understanding the relationship between homoeologues can inform approaches to modulate the response of quantitative traits in polyploid wheat; we also argue that functional redundancy has 'locked up' a wide range of phenotypic variation in wheat. We explore how genomics provides key tools to inform targeted manipulation of multiple homoeologues, thereby allowing researchers and plant breeders to unlock the full polyploid potential of wheat. PMID:26108556

  5. Relationship between Russian wheat aphid abundance and edaphic and topographic characteristics of wheat fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study explores the spatial relationship between Russian wheat aphid population density and variation in edaphic or topographic factors within wheat fields. Multiple regression analysis was applied to data collected from six wheat fields located in three States, Colorado, Wyoming, and Nebraska....

  6. Resistance among U.S. wheat Triticum aestivum cultivars to the wheat pathotype of Magnaporthe oryzae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Magnaporthe oryzae is the causal agent of blast on several graminaceous plants. The M. oryzae population causing wheat blast has not been found outside South America. U.S. wheat production is at risk to this pathogen if introduced and established. Proactive testing of US wheat cultivars for their re...

  7. Registration of Warhorse wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'Warhorse' (Reg. No. CV-1096, PI 670157) hard red winter (HRW) wheat (Triticum aestivum L.) was developed and released by the Montana Agricultural Experiment Station in September 2013. Warhorse is of unknown pedigree, derived from a composite of three topcrosses made to the same F1 population in 200...

  8. Population Diversity of Yeasts and Lactic Acid Bacteria in Pig Feed Fermented with Whey, Wet Wheat Distillers' Grains, or Water at Different Temperatures?

    PubMed Central

    Olstorpe, Matilda; Lyberg, Karin; Lindberg, Jan Erik; Schnrer, Johan; Passoth, Volkmar

    2008-01-01

    The diversity of populations of yeast and lactic acid bacteria (LAB) in pig feeds fermented at 10, 15, or 20C was characterized by rRNA gene sequencing of isolates. The feeds consisted of a cereal grain mix blended with wet wheat distillers' grains (WWDG feed), whey (W feed), or tap water (WAT feed). Fermentation proceeded for 5 days without disturbance, followed by 14 days of daily simulated feed outtakes, in which 80% of the contents were replaced with fresh feed mixtures. In WWDG feed, Pichia galeiformis became the dominant yeast species, independent of the fermentation temperature and feed change. The LAB population was dominated by Pediococcus pentosaceus at the start of the fermentation period. After 3 days, the Lactobacillus plantarum population started to increase in feeds at all temperatures. The diversity of LAB increased after the addition of fresh feed components. In W feed, Kluyveromyces marxianus dominated, but after the feed change, the population diversity increased. With increasing fermentation temperatures, there was a shift toward Pichia membranifaciens as the dominant species. L. plantarum was the most prevalent LAB in W feed. The WAT feed had a diverse microbial flora, and the yeast population changed throughout the whole fermentation period. Pichia anomala was the most prevalent yeast species, with increasing occurrence at higher fermentation temperatures. Pediococcus pentosaceus was the most prevalent LAB, but after the feed change, L. plantarum started to proliferate. The present study demonstrates that the species composition in fermented pig feed may vary considerably, even if viable cell counts indicate stable microbial populations. PMID:18223110

  9. Population diversity of yeasts and lactic acid bacteria in pig feed fermented with whey, wet wheat distillers' grains, or water at different temperatures.

    PubMed

    Olstorpe, Matilda; Lyberg, Karin; Lindberg, Jan Erik; Schnrer, Johan; Passoth, Volkmar

    2008-03-01

    The diversity of populations of yeast and lactic acid bacteria (LAB) in pig feeds fermented at 10, 15, or 20 degrees C was characterized by rRNA gene sequencing of isolates. The feeds consisted of a cereal grain mix blended with wet wheat distillers' grains (WWDG feed), whey (W feed), or tap water (WAT feed). Fermentation proceeded for 5 days without disturbance, followed by 14 days of daily simulated feed outtakes, in which 80% of the contents were replaced with fresh feed mixtures. In WWDG feed, Pichia galeiformis became the dominant yeast species, independent of the fermentation temperature and feed change. The LAB population was dominated by Pediococcus pentosaceus at the start of the fermentation period. After 3 days, the Lactobacillus plantarum population started to increase in feeds at all temperatures. The diversity of LAB increased after the addition of fresh feed components. In W feed, Kluyveromyces marxianus dominated, but after the feed change, the population diversity increased. With increasing fermentation temperatures, there was a shift toward Pichia membranifaciens as the dominant species. L. plantarum was the most prevalent LAB in W feed. The WAT feed had a diverse microbial flora, and the yeast population changed throughout the whole fermentation period. Pichia anomala was the most prevalent yeast species, with increasing occurrence at higher fermentation temperatures. Pediococcus pentosaceus was the most prevalent LAB, but after the feed change, L. plantarum started to proliferate. The present study demonstrates that the species composition in fermented pig feed may vary considerably, even if viable cell counts indicate stable microbial populations. PMID:18223110

  10. Population Dynamics and Metabolite Target Analysis of Lactic Acid Bacteria during Laboratory Fermentations of Wheat and Spelt Sourdoughs▿

    PubMed Central

    Van der Meulen, Roel; Scheirlinck, Ilse; Van Schoor, Ann; Huys, Geert; Vancanneyt, Marc; Vandamme, Peter; De Vuyst, Luc

    2007-01-01

    Four laboratory sourdough fermentations, initiated with wheat or spelt flour and without the addition of a starter culture, were prepared over a period of 10 days with daily back-slopping. Samples taken at all refreshment steps were used for determination of the present microbiota. Furthermore, an extensive metabolite target analysis of more than 100 different compounds was performed through a combination of various chromatographic methods including liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. The establishment of a stable microbial ecosystem occurred through a three-phase evolution within a week, as revealed by both microbiological and metabolite analyses. Strains of Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus rossiae, Lactobacillus brevis, and Lactobacillus paraplantarum were dominating some of the sourdough ecosystems. Although the heterofermentative L. fermentum was dominating one of the wheat sourdoughs, all other sourdoughs were dominated by a combination of obligate and facultative heterofermentative taxa. Strains of homofermentative species were not retrieved in the stable sourdough ecosystems. Concentrations of sugar and amino acid metabolites hardly changed during the last days of fermentation. Besides lactic acid, ethanol, and mannitol, the production of succinic acid, erythritol, and various amino acid metabolites, such as phenyllactic acid, hydroxyphenyllactic acid, and indolelactic acid, was shown during fermentation. Physiologically, they contributed to the equilibration of the redox balance. The biphasic approach of the present study allowed us to map some of the interactions taking place during sourdough fermentation and helped us to understand the fine-tuned metabolism of lactic acid bacteria, which allows them to dominate a food ecosystem. PMID:17557853

  11. Eat Wheat!

    ERIC Educational Resources Information Center

    Idaho Wheat Commission, Boise.

    This pamphlet contains puzzles, games, and a recipe designed to teach elementary school pupils about wheat. It includes word games based on the U.S. Department of Agriculture Food Guide Pyramid and on foods made from wheat. The Food Guide Pyramid can be cut out of the pamphlet and assembled as a three-dimensional information source and food guide.…

  12. Wheat Newsletter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This review was written for readers of the Annual Wheat Newsletter, Volume 53. It summarizes activities on wheat research during 2006 at the U.S. Grain Marketing Research Laboratory (USGMRL). The article includes technical abstracts of research accomplishments from the Grain Quality and Structure ...

  13. Control of Galactosyl Diglycerides in Wheat Endosperm by Group 5 Chromosomes

    PubMed Central

    Hernandez-Lucas, C.; De Caleya, R. Fernandez; Carbonero, Pilar; Garcia-Olmedo, F.

    1977-01-01

    Lower levels of monogalactosyl diglyceride (MGDG) and digalactosyl diglyceride (DGDG) have been found in tetraploid wheats as compared with those in hexaploid wheats. The same difference has been found between hexaploid cultivars and tetraploid lines derived from them by D genome extraction. A lower level of MGDG and DGDG is also present in Triticum carthlicum (AABB) as compared with Aegilops squarrosa (DD) or with the synthetic T. spelta (AABBDD) obtained from them. Analysis of the appropriate nullitetrasomic and ditelosomic lines indicates that a gene or genes located in the short arm of chromosome 5D are responsible for the observed difference and that group 5 chromosomes can be ranked as to their influence on the MGDG and DGDG levels in the order 5B > 5D > 5A and 5D > 5B > 5A, respectively. These results further support our previous identification of DGDG as the lipid factor responsible for petroleum ether solubility of lipopurothionins. Since DGDG contributes to baking quality by improving the retention of fermentation gases, the present observations imply that the difference in bread-making quality between the two types of wheat is not due only to proteins contributed by the D genome. PMID:17248744

  14. Transcriptome de novo assembly from next-generation sequencing and comparative analyses in the hexaploid salt marsh species Spartina maritima and Spartina alterniflora (Poaceae)

    PubMed Central

    Ferreira de Carvalho, J; Poulain, J; Da Silva, C; Wincker, P; Michon-Coudouel, S; Dheilly, A; Naquin, D; Boutte, J; Salmon, A; Ainouche, M

    2013-01-01

    Spartina species have a critical ecological role in salt marshes and represent an excellent system to investigate recurrent polyploid speciation. Using the 454 GS-FLX pyrosequencer, we assembled and annotated the first reference transcriptome (from roots and leaves) for two related hexaploid Spartina species that hybridize in Western Europe, the East American invasive Spartina alterniflora and the Euro-African S. maritima. The de novo read assembly generated 38?478 consensus sequences and 99% found an annotation using Poaceae databases, representing a total of 16?753 non-redundant genes. Spartina expressed sequence tags were mapped onto the Sorghum bicolor genome, where they were distributed among the subtelomeric arms of the 10 S. bicolor chromosomes, with high gene density correlation. Normalization of the complementary DNA library improved the number of annotated genes. Ecologically relevant genes were identified among GO biological function categories in salt and heavy metal stress response, C4 photosynthesis and in lignin and cellulose metabolism. Expression of some of these genes had been found to be altered by hybridization and genome duplication in a previous microarray-based study in Spartina. As these species are hexaploid, up to three duplicated homoeologs may be expected per locus. When analyzing sequence polymorphism at four different loci in S. maritima and S. alterniflora, we found up to four haplotypes per locus, suggesting the presence of two expressed homoeologous sequences with one or two allelic variants each. This reference transcriptome will allow analysis of specific Spartina genes of ecological or evolutionary interest, estimation of homoeologous gene expression variation using RNA-seq and further gene expression evolution analyses in natural populations. PMID:23149455

  15. Transcriptome de novo assembly from next-generation sequencing and comparative analyses in the hexaploid salt marsh species Spartina maritima and Spartina alterniflora (Poaceae).

    PubMed

    Ferreira de Carvalho, J; Poulain, J; Da Silva, C; Wincker, P; Michon-Coudouel, S; Dheilly, A; Naquin, D; Boutte, J; Salmon, A; Ainouche, M

    2013-02-01

    Spartina species have a critical ecological role in salt marshes and represent an excellent system to investigate recurrent polyploid speciation. Using the 454 GS-FLX pyrosequencer, we assembled and annotated the first reference transcriptome (from roots and leaves) for two related hexaploid Spartina species that hybridize in Western Europe, the East American invasive Spartina alterniflora and the Euro-African S. maritima. The de novo read assembly generated 38?478 consensus sequences and 99% found an annotation using Poaceae databases, representing a total of 16?753 non-redundant genes. Spartina expressed sequence tags were mapped onto the Sorghum bicolor genome, where they were distributed among the subtelomeric arms of the 10 S. bicolor chromosomes, with high gene density correlation. Normalization of the complementary DNA library improved the number of annotated genes. Ecologically relevant genes were identified among GO biological function categories in salt and heavy metal stress response, C4 photosynthesis and in lignin and cellulose metabolism. Expression of some of these genes had been found to be altered by hybridization and genome duplication in a previous microarray-based study in Spartina. As these species are hexaploid, up to three duplicated homoeologs may be expected per locus. When analyzing sequence polymorphism at four different loci in S. maritima and S. alterniflora, we found up to four haplotypes per locus, suggesting the presence of two expressed homoeologous sequences with one or two allelic variants each. This reference transcriptome will allow analysis of specific Spartina genes of ecological or evolutionary interest, estimation of homoeologous gene expression variation using RNA-seq and further gene expression evolution analyses in natural populations. PMID:23149455

  16. Transcriptome-scale homoeolog-specific transcript assemblies of bread wheat

    PubMed Central

    2012-01-01

    Background Bread wheat is one of the world’s most important food crops and considerable efforts have been made to develop genomic resources for this species. This includes an on-going project by the International Wheat Genome Sequencing Consortium to assemble its large and complex genome, which is hexaploid and contains three closely related ‘homoeologous’ copies for each chromosome. This multi-national effort avoids the complications polyploidy entails for correct assembly of the genome by sequencing flow-sorted chromosome arms one at a time. Here we report on an alternate approach, a direct homoeolog-specific assembly of the expressed portion of the genome, the transcriptome. Results After assessment of the ability of various assemblers to generate homoeolog-specific assemblies, we employed a two-stage assembly process to produce a high-quality assembly of the transcriptome of hexaploid wheat from Roche-454 and Illumina GAIIx paired-end sequence reads. The assembly process made use of a rapid partitioning of expressed sequences into homoeologous clusters, followed by a parallel high-fidelity assembly of each cluster on a 1150-processor compute cloud. We assessed assembly quality through comparison to known wheat gene sequences and found that in ca. 98.5% of cases the assembly was sufficiently accurate for homoeologous triplets to be cleanly separated into either two or three separate contigs. Comparison to publicly available transcript collections suggests that the assembly covers ~75-80% of the complete transcriptome. Conclusions This work therefore describes the first homoeolog-specific sequence assembly of the wheat transcriptome and provides a reference transcriptome for future wheat research. Furthermore, our assembly methodology is transferable to other polyploid organisms. PMID:22989011

  17. Haplotype diversity of preharvest sprouting QTLs in wheat.

    PubMed

    Ogbonnaya, Francis C; Imtiaz, Muhammad; DePauw, Ron M

    2007-02-01

    Preharvest sprouting (PHS) is one of the most important factors affecting wheat production worldwide in environments characterized by rainfall and high humidity at harvest. In such environments, the incorporation of seed dormancy of a limited duration is required to minimize losses associated with PHS. A global collection of 28 PHS-resistant and -susceptible wheat germplasm was characterized with microsatellite markers flanking the genomic regions associated with PHS-resistance quantitative trait loci (QTLs), particularly on chromosomes 3D and 4A. The genetic diversity analysis revealed 380 alleles at 54 microsatellite loci, with an average of 7.0 alleles per locus, among the 28 wheat genotypes. Gower's genetic similarity values among all possible pairs of genotypes varied from 0.44 to 0.97, indicating that there is considerable diversity in the PHS germplasm evaluated. Cluster and principal coordinates analysis of genetic similarity estimates differentiated the genotypes into groups, according to their source of PHS resistance. Three major SSR haplotypes were observed on chromosome 4AL, designated RL4137-type allele, Aus1408-type allele, and synthetic-hexaploid-type allele. The RL4137-type allele was prevalent in Canadian cultivars, mostly in cluster 6, followed by the Aus1408-type and its derivatives in clusters 4 and 5. The Syn36 and Syn37 alleles on chromosome 4AL were rare. On chromosome 3DL, the SSRs haplotypes derived from Syn36 and Syn37 were also rare, and proved unique to the Aegilops tauschii - derived synthetic hexaploids. They are therefore likely carrying resistance genes different from those previously reported. Based on genetic relationships, PHS resistance might be improved by selecting parental genotypes from different clusters. PMID:17546076

  18. Additive-dominance genetic model analyses for late-maturity alpha-amylase activity in a bread wheat factorial crossing population.

    PubMed

    Rasul, Golam; Glover, Karl D; Krishnan, Padmanaban G; Wu, Jixiang; Berzonsky, William A; Ibrahim, Amir M H

    2015-12-01

    Elevated level of late maturity ?-amylase activity (LMAA) can result in low falling number scores, reduced grain quality, and downgrade of wheat (Triticum aestivum L.) class. A mating population was developed by crossing parents with different levels of LMAA. The F2 and F3 hybrids and their parents were evaluated for LMAA, and data were analyzed using the R software package 'qgtools' integrated with an additive-dominance genetic model and a mixed linear model approach. Simulated results showed high testing powers for additive and additiveנenvironment variances, and comparatively low powers for dominance and dominanceנenvironment variances. All variance components and their proportions to the phenotypic variance for the parents and hybrids were significant except for the dominanceנenvironment variance. The estimated narrow-sense heritability and broad-sense heritability for LMAA were 14 and 54%, respectively. High significant negative additive effects for parents suggest that spring wheat cultivars 'Lancer' and 'Chester' can serve as good general combiners, and that 'Kinsman' and 'Seri-82' had negative specific combining ability in some hybrids despite of their own significant positive additive effects, suggesting they can be used as parents to reduce LMAA levels. Seri-82 showed very good general combining ability effect when used as a male parent, indicating the importance of reciprocal effects. High significant negative dominance effects and high-parent heterosis for hybrids demonstrated that the specific hybrid combinations; ChesterנKinsman, 'Lerma52'נLancer, Lerma52נ'LoSprout' and 'Janz'נSeri-82 could be generated to produce cultivars with significantly reduced LMAA level. PMID:26403988

  19. [Interrelationship between water use efficiency and nitrogen use efficiency of different wheat evolution materials].

    PubMed

    Li, Yangyang; Zhang, Suiqi; Shao, Mingan

    2003-09-01

    A field micro-plot experiment on the interrelationship between water use efficiency and nitrogen use efficiency of different wheat evolution materials at the whole plant level showed that both water and nitrogen use efficiency increased gradually during the long evolution process from diploid to hexaploid. The water use efficiency was positively related with nitrogen use efficiency across nine evolution materials excluding French S. cereals, suggesting that the high nitrogen use efficiency of French S. cereals might be related with physiological mechanisms other than WUE. PMID:14733002

  20. Origin, Migration Routes and Worldwide Population Genetic Structure of the Wheat Yellow Rust Pathogen Puccinia striiformis f.sp. tritici

    PubMed Central

    Ali, Sajid; Gladieux, Pierre; Leconte, Marc; Gautier, Anglique; Justesen, Annemarie F.; Hovmller, Mogens S.; Enjalbert, Jrme; de Vallavieille-Pope, Claude

    2014-01-01

    Analyses of large-scale population structure of pathogens enable the identification of migration patterns, diversity reservoirs or longevity of populations, the understanding of current evolutionary trajectories and the anticipation of future ones. This is particularly important for long-distance migrating fungal pathogens such as Puccinia striiformis f.sp. tritici (PST), capable of rapid spread to new regions and crop varieties. Although a range of recent PST invasions at continental scales are well documented, the worldwide population structure and the center of origin of the pathogen were still unknown. In this study, we used multilocus microsatellite genotyping to infer worldwide population structure of PST and the origin of new invasions based on 409 isolates representative of distribution of the fungus on six continents. Bayesian and multivariate clustering methods partitioned the set of multilocus genotypes into six distinct genetic groups associated with their geographical origin. Analyses of linkage disequilibrium and genotypic diversity indicated a strong regional heterogeneity in levels of recombination, with clear signatures of recombination in the Himalayan (Nepal and Pakistan) and near-Himalayan regions (China) and a predominant clonal population structure in other regions. The higher genotypic diversity, recombinant population structure and high sexual reproduction ability in the Himalayan and neighboring regions suggests this area as the putative center of origin of PST. We used clustering methods and approximate Bayesian computation (ABC) to compare different competing scenarios describing ancestral relationship among ancestral populations and more recently founded populations. Our analyses confirmed the Middle East-East Africa as the most likely source of newly spreading, high-temperature-adapted strains; Europe as the source of South American, North American and Australian populations; and Mediterranean-Central Asian populations as the origin of South African populations. Although most geographic populations are not markedly affected by recent dispersal events, this study emphasizes the influence of human activities on recent long-distance spread of the pathogen. PMID:24465211

  1. Origin, migration routes and worldwide population genetic structure of the wheat yellow rust pathogen Puccinia striiformis f.sp. tritici.

    PubMed

    Ali, Sajid; Gladieux, Pierre; Leconte, Marc; Gautier, Anglique; Justesen, Annemarie F; Hovmller, Mogens S; Enjalbert, Jrme; de Vallavieille-Pope, Claude

    2014-01-01

    Analyses of large-scale population structure of pathogens enable the identification of migration patterns, diversity reservoirs or longevity of populations, the understanding of current evolutionary trajectories and the anticipation of future ones. This is particularly important for long-distance migrating fungal pathogens such as Puccinia striiformis f.sp. tritici (PST), capable of rapid spread to new regions and crop varieties. Although a range of recent PST invasions at continental scales are well documented, the worldwide population structure and the center of origin of the pathogen were still unknown. In this study, we used multilocus microsatellite genotyping to infer worldwide population structure of PST and the origin of new invasions based on 409 isolates representative of distribution of the fungus on six continents. Bayesian and multivariate clustering methods partitioned the set of multilocus genotypes into six distinct genetic groups associated with their geographical origin. Analyses of linkage disequilibrium and genotypic diversity indicated a strong regional heterogeneity in levels of recombination, with clear signatures of recombination in the Himalayan (Nepal and Pakistan) and near-Himalayan regions (China) and a predominant clonal population structure in other regions. The higher genotypic diversity, recombinant population structure and high sexual reproduction ability in the Himalayan and neighboring regions suggests this area as the putative center of origin of PST. We used clustering methods and approximate Bayesian computation (ABC) to compare different competing scenarios describing ancestral relationship among ancestral populations and more recently founded populations. Our analyses confirmed the Middle East-East Africa as the most likely source of newly spreading, high-temperature-adapted strains; Europe as the source of South American, North American and Australian populations; and Mediterranean-Central Asian populations as the origin of South African populations. Although most geographic populations are not markedly affected by recent dispersal events, this study emphasizes the influence of human activities on recent long-distance spread of the pathogen. PMID:24465211

  2. Homoeolog-specific transcriptional bias in allopolyploid wheat

    PubMed Central

    2010-01-01

    Background Interaction between parental genomes is accompanied by global changes in gene expression which, eventually, contributes to growth vigor and the broader phenotypic diversity of allopolyploid species. In order to gain a better understanding of the effects of allopolyploidization on the regulation of diverged gene networks, we performed a genome-wide analysis of homoeolog-specific gene expression in re-synthesized allohexaploid wheat created by the hybridization of a tetraploid derivative of hexaploid wheat with the diploid ancestor of the wheat D genome Ae. tauschii. Results Affymetrix wheat genome arrays were used for both the discovery of divergent homoeolog-specific mutations and analysis of homoeolog-specific gene expression in re-synthesized allohexaploid wheat. More than 34,000 detectable parent-specific features (PSF) distributed across the wheat genome were used to assess AB genome (could not differentiate A and B genome contributions) and D genome parental expression in the allopolyploid transcriptome. In re-synthesized polyploid 81% of PSFs detected mid-parent levels of gene expression, and only 19% of PSFs showed the evidence of non-additive expression. Non-additive expression in both AB and D genomes was strongly biased toward up-regulation of parental type of gene expression with only 6% and 11% of genes, respectively, being down-regulated. Of all the non-additive gene expression, 84% can be explained by differences in the parental genotypes used to make the allopolyploid. Homoeolog-specific co-regulation of several functional gene categories was found, particularly genes involved in photosynthesis and protein biosynthesis in wheat. Conclusions Here, we have demonstrated that the establishment of interactions between the diverged regulatory networks in allopolyploids is accompanied by massive homoeolog-specific up- and down-regulation of gene expression. This study provides insights into interactions between homoeologous genomes and their role in growth vigor, development, and fertility of allopolyploid species. PMID:20849627

  3. Fine mapping of Hch1, the causal D-genome gene for hybrid chlorosis in interspecific crosses between tetraploid wheat and Aegilops tauschii.

    PubMed

    Hirao, Kana; Nishijima, Ryo; Sakaguchi, Kohei; Takumi, Shigeo

    2016-03-23

    Hybrid chlorosis, one of the reproductive barriers between tetraploid wheat and its D-genome progenitor, Aegilops tauschii, inhibits normal growth of synthetic wheat hexaploids. Hybrid chlorosis appears to be due to an epistatic interaction of two loci from the AB and D wheat genomes. Our previous study assigned the causal D-genome gene for hybrid chlorosis, Hch1, to the short arm of chromosome 7D. Here, we constructed a fine map of 7DS near Hch1 using 280 F2 individuals from a cross of two wheat synthetic lines, one showing normal growth and the other showing hybrid chlorosis. The hybrid chlorosis phenotype was controlled by a single dominant allele of the Hch1 locus in the synthetic hexaploids. Hch1 was closely linked to four new markers within 0.2 cM, and may be localized near or within the two Ae. tauschii scaffolds containing the linked markers on 7DS. Comparative analysis of the Hch1 chromosomal region for Ae. tauschii, barley and Brachypodium showed that a local inversion occurred in the region proximal to Hch1 during the divergence between barley and Ae. tauschii, and that the Hch1 region on wheat 7DS is syntenic to Brachypodium chromosome 1. These observations provide useful information for further studies toward map-based cloning of Hch1. PMID:26687862

  4. WheatGenome.info: an integrated database and portal for wheat genome information.

    PubMed

    Lai, Kaitao; Berkman, Paul J; Lorenc, Michal Tadeusz; Duran, Chris; Smits, Lars; Manoli, Sahana; Stiller, Jiri; Edwards, David

    2012-02-01

    Bread wheat (Triticum aestivum) is one of the most important crop plants, globally providing staple food for a large proportion of the human population. However, improvement of this crop has been limited due to its large and complex genome. Advances in genomics are supporting wheat crop improvement. We provide a variety of web-based systems hosting wheat genome and genomic data to support wheat research and crop improvement. WheatGenome.info is an integrated database resource which includes multiple web-based applications. These include a GBrowse2-based wheat genome viewer with BLAST search portal, TAGdb for searching wheat second-generation genome sequence data, wheat autoSNPdb, links to wheat genetic maps using CMap and CMap3D, and a wheat genome Wiki to allow interaction between diverse wheat genome sequencing activities. This system includes links to a variety of wheat genome resources hosted at other research organizations. This integrated database aims to accelerate wheat genome research and is freely accessible via the web interface at http://www.wheatgenome.info/. PMID:22009731

  5. Absence of mitochondrial DNA sequence variation in Russian wheat aphid (Hemiptera: Aphididae) populations consistent with a single introduction into the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), was introduced into North America in Mexico during 1980 and by 1988 had spread north across the Western US into Southern Canada. South Africa has been suspected as the source of the introduction. RWA is the major insect pest of wheat and barl...

  6. IMPROVING BIOLOGICAL CONTROL OF AN INVASIVE PEST WITH MOLECULAR PHYLOGEOGRAPHIC AND POPULATION GENETIC APPROACHES: THE WHEAT STEM SAWFLY, CEPHUS CINCTUS NORTON, (HYMENOPTERA : CEPHIDAE) AS A CASE STUDY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The wheat stem sawfly (WSS), Cephus cinctus Norton (Hymenoptera: Cephidae) has become a chronic pest of wheat in the semi-arid steppe region of the North American Great Plains. To develop a more general and conceptual framework with predictive value for the biological control of this pest, it is imp...

  7. NITROGEN USE AND BIOMASS DISTRIBUTION IN CULMS OF WINTER WHEAT POPULATIONS SELECTED FROM GRAIN-ONLY AND DUAL-PURPOSE SYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beginning in late fall and ending at jointing in early spring winter wheat (Triticum aestivum L.) crops in the southern Great Plains are often grazed by stocker cattle (Bos tarus L.) and then harvested for grain. Traditionally, dual-purpose (grazing plus grain) wheat cultivars are developed from a g...

  8. Introgression of a 4D chromosomal fragment into durum wheat confers aluminium tolerance

    PubMed Central

    Han, Chang; Ryan, Peter R.; Yan, ZeHong; Delhaize, Emmanuel

    2014-01-01

    Background and Aim Aluminium (Al3+) inhibits root growth of sensitive plant species and is a key factor that limits durum wheat (Triticum turgidum) production on acid soils. The aim of this study was to enhance the Al3+ tolerance of an elite durum cultivar by introgression of a chromosomal fragment from hexaploid wheat (Triticum aestivum) that possesses an Al3+ tolerance gene. Methods A 4D(4B) substitution line of durum wheat Langdon was backcrossed to Jandaroi, a current semi-dwarf Australian durum. In the second backcross, using Jandaroi as the recurrent parent, a seedling was identified where TaALMT1 on chromosome 4D was recombined with the Rht-B1b locus on chromosome 4B to yield an Al3+-tolerant seedling with a semi-dwarf habit. This seedling was used in a third backcross to generate homozygous sister lines with contrasting Al3+ tolerances. The backcrossed lines were characterized and compared with selected cultivars of hexaploid wheat for their Al3+ and Na+ tolerances in hydroponic culture as well as in short-term experiments to assess their growth on acid soil. Key Results Analysis of sister lines derived from the third backcross showed that the 4D chromosomal fragment substantially enhanced Al3+ tolerance. The ability to exclude Na+ from leaves was also enhanced, indicating that the chromosomal fragment possessed the Kna1 salt tolerance locus. Although Al3+ tolerance of seminal roots was enhanced in acid soil, the development of fine roots was not as robust as found in Al3+-tolerant lines of hexaploid wheat. Analysis of plant characteristics in the absence of Al3+ toxicity showed that the introgressed fragment did not affect total grain yield but reduced the weight of individual grains. Conclusions The results show that it is possible to increase substantially the Al3+ tolerance of an elite durum wheat cultivar by introgression of a 4D chromosomal fragment. Further improvements are possible, such as introducing additional genes to enhance the Al3+ tolerance of fine roots and by eliminating the locus on the chromosomal fragment responsible for smaller grain weights. PMID:24737716

  9. Wheat: The Whole Story.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Education, Oklahoma City.

    This publication presents information on wheat. Wheat was originally a wild grass and not native to the United States. Wheat was not planted there until 1777 (and then only as a hobby crop). Wheat is grown on more acres than any other grain in this country. Soft wheats are grown east of the Mississippi River, and hard wheats are grown west of the…

  10. Accelerated Senescence and Enhanced Disease Resistance in Hybrid Chlorosis Lines Derived from Interspecific Crosses between Tetraploid Wheat and Aegilops tauschii

    PubMed Central

    Tosa, Yukio; Yoshida, Kentaro; Park, Pyoyun; Takumi, Shigeo

    2015-01-01

    Hybrid chlorosis, a type of hybrid incompatibility, has frequently been reported in inter- and intraspecific crosses of allopolyploid wheat. In a previous study, we reported some types of growth abnormalities such as hybrid necrosis and observed hybrid chlorosis with mild or severe abnormalities in wheat triploids obtained in crosses between tetraploid wheat cultivar Langdon and four Ae. tauschii accessions and in their derived synthetic hexaploids. However, the molecular mechanisms underlying hybrid chlorosis are not well understood. Here, we compared cytology and gene expression in leaves to characterize the abnormal growth in wheat synthetics showing mild and severe chlorosis. In addition, we compared disease resistance to wheat blast fungus. In total 55 and 105 genes related to carbohydrate metabolism and 53 and 89 genes for defense responses were markedly up-regulated in the mild and severe chlorosis lines, respectively. Abnormal chloroplasts formed in the mesophyll cells before the leaves yellowed in the hybrid chlorosis lines. The plants with mild chlorosis showed increased resistance to wheat blast and powdery mildew fungi, although significant differences only in two, third internode length and maturation time, out of the examined agricultural traits were found between the wild type and plants showing mild chlorosis. These observations suggest that senescence might be accelerated in hybrid chlorosis lines of wheat synthetics. Moreover, in wheat synthetics showing mild chlorosis, the negative effects on biomass can be minimized, and they may show substantial fitness under pathogen-polluted conditions. PMID:25806790

  11. The usefulness of fungicide mixtures and alternation for delaying the selection for resistance in populations of Mycosphaerella graminicola on winter wheat: a modeling analysis.

    PubMed

    Hobbelen, P H F; Paveley, N D; Oliver, R P; van den Bosch, F

    2013-07-01

    A fungicide resistance model (reported and tested previously) was amended to describe the development of resistance in Mycosphaerella graminicola populations in winter wheat (Triticum aestivum) crops in two sets of fields, connected by spore dispersal. The model was used to evaluate the usefulness of concurrent, alternating, or mixture use of two high-resistance-risk fungicides as resistance management strategies. We determined the effect on the usefulness of each strategy of (i) fitness costs of resistance, (ii) partial resistance to fungicides, (iii) differences in the dose-response curves and decay rates between fungicides, and (iv) different frequencies of the double-resistant strain at the start of a treatment strategy. Parameter values for the quinine outside inhibitor pyraclostrobin were used to represent two fungicides with differing modes of action. The effectiveness of each strategy was quantified as the maximum number of growing seasons that disease was effectively controlled in both sets of fields. For all scenarios, the maximum effective lives achieved by the use of the strategies were in the order mixtures ? alternation ? concurrent use. Mixtures were of particular benefit where the pathogen strain resistant to both modes of action incurred a fitness penalty or was present at a low initial frequency. PMID:23384858

  12. The effect of wheat prebiotics on the gut bacterial population and iron status of iron deficient broiler chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years, there is a lot of interest in improving the intestinal health, and consequently increasing minerals as iron absorption, by managing the intestinal microbial population. This is traditionally done by the consumption of probiotics, which are live microbial food supplements. However, a...

  13. Spatial and temporal differences in the frequency of 3ADON-producing Fusarium graminearum populations in Canadian wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multilocus genotyping of 492 Fusarium graminearum from five Canadian provinces documented a 14-fold increase in 3ADON-producing F. graminearum between 1998 and 2004 in the three western Canadian provinces examined. Significant population structure associated with trichothecene chemotype differences...

  14. Cytological analysis on the distribution and origin of the alien chromosome pair conferring blue aleurone color in several European common wheat (Triticum aestivum L.) strains.

    PubMed

    Zeller, F J; Cermeo, M C; Miller, T E

    1991-04-01

    Meiotic chromosome pairing and Giemsa C-banding analyses in crosses of several European blue-grained wheat strains with Chinese Spring double ditelosomic and other aneuploid lines showed that Triticum aestivum Blaukorn strains "Berlin," "Probstdorf," "Tschermak," and "Weihenstephan" are chromosome substitutions, in which the complete wheat chromosome 4A pair is replaced, whereas the strains "Brnn" and "Moskau" are 4B substitutions. The alien chromosome pair in all of these strains is an A genome chromosome (4A) from diploid Triticum monococcum or T. boeoticum not present in common tetraploid and hexaploid cultivated wheats. The Blaukorn strain Weihenstephan "W 70a86" possesses, in addition to a rye chromosome pair 5R compensating for the loss of part of chromosome 5D, a 4A/5DL translocation replacing chromosome pair 4B of wheat. PMID:24221323

  15. The Protein Disulfide Isomerase gene family in bread wheat (T. aestivum L.)

    PubMed Central

    2010-01-01

    Background The Protein Disulfide Isomerase (PDI) gene family encodes several PDI and PDI-like proteins containing thioredoxin domains and controlling diversified metabolic functions, including disulfide bond formation and isomerisation during protein folding. Genomic, cDNA and promoter sequences of the three homoeologous wheat genes encoding the "typical" PDI had been cloned and characterized in a previous work. The purpose of present research was the cloning and characterization of the complete set of genes encoding PDI and PDI like proteins in bread wheat (Triticum aestivum cv Chinese Spring) and the comparison of their sequence, structure and expression with homologous genes from other plant species. Results Eight new non-homoeologous wheat genes were cloned and characterized. The nine PDI and PDI-like sequences of wheat were located in chromosome regions syntenic to those in rice and assigned to eight plant phylogenetic groups. The nine wheat genes differed in their sequences, genomic organization as well as in the domain composition and architecture of their deduced proteins; conversely each of them showed high structural conservation with genes from other plant species in the same phylogenetic group. The extensive quantitative RT-PCR analysis of the nine genes in a set of 23 wheat samples, including tissues and developmental stages, showed their constitutive, even though highly variable expression. Conclusions The nine wheat genes showed high diversity, while the members of each phylogenetic group were highly conserved even between taxonomically distant plant species like the moss Physcomitrella patens. Although constitutively expressed the nine wheat genes were characterized by different expression profiles reflecting their different genomic organization, protein domain architecture and probably promoter sequences; the high conservation among species indicated the ancient origin and diversification of the still evolving gene family. The comprehensive structural and expression characterization of the complete set of PDI and PDI-like wheat genes represents a basis for the functional characterization of this gene family in the hexaploid context of bread wheat. PMID:20525253

  16. Phenotypic assessment and mapped markers for H31, a new wheat gene conferring resistance to Hessian fly (Diptera: Cecidomyiidae).

    PubMed

    Williams, C E; Collier, C C; Sardesai, N; Ohm, H W; Cambron, S E

    2003-11-01

    A new source of resistance to the highly virulent and widespread biotype L of the Hessian fly, Mayetiola destructor (Say), was identified in an accession of tetraploid durum wheat, Triticum turgidum Desf., and was introgressed into hexaploid common wheat, Triticum aestivum L. Genetic analysis and deletion mapping revealed that the common wheat line contained a single locus for resistance, H31, residing at the terminus of chromosome 5BS. H31 is the first Hessian fly-resistance gene to be placed on 5BS, making it unique from all previously reported sources of resistance. AFLP analysis identified two markers linked to the resistance locus. These markers were converted to highly specific sequence-tagged site markers. The markers are being applied to the development of cultivars carrying multiple genes for resistance to Hessian fly biotype L in order to test gene pyramiding as a strategy for extending the durability of deployed resistance. PMID:12928782

  17. The Localization and Expression of the Class II Starch Synthases of Wheat1

    PubMed Central

    Li, Zhongyi; Chu, Xiusheng; Mouille, Gregory; Yan, Liuling; Kosar-Hashemi, Behjat; Hey, Sandra; Napier, Johnathan; Shewry, Peter; Clarke, Bryan; Appels, Rudi; Morell, Matthew K.; Rahman, Sadequr

    1999-01-01

    The starch granules of hexaploid wheat (Triticum aestivum) contain a group of three proteins known as SGP-1 (starch granule protein-1) proteins, which have apparent molecular masses of 100, 108, and 115 kD. The nature and role of these proteins has not been defined previously. We demonstrate that these polypeptides are starch synthases that are present in both the starch granule and the soluble fraction at the early stages of wheat endosperm development, but that are exclusively granule bound at mid and late endosperm development. A partial cDNA clone encoding a fragment of the 100-kD protein was obtained by screening a wheat endosperm cDNA expression library using monoclonal antibodies. Three classes of cDNA were subsequently isolated from a wheat endosperm cDNA library by nucleic acid hybridization and were shown to encode the 100-, 108-, and 115-kD proteins. The cDNA sequences are highly homologous to class II starch synthases and have the highest homology with the maize SSIIa (starch synthase IIa) gene. mRNA for the SGP-1 proteins was detected in the leaf, pre-anthesis florets, and endosperm of wheat and is highly expressed in the leaf and in the grain during the early to mid stages of development. We discuss the roles of the SGP-1 proteins in starch biosynthesis in wheat. PMID:10444098

  18. Discovery, evaluation and distribution of haplotypes and new alleles of the Photoperiod-A1 gene in wheat.

    PubMed

    Muterko, Alexandr; Kalendar, Ruslan; Cockram, James; Balashova, Irina

    2015-05-01

    Photoperiod response in wheat is determined to a large extent by the homoeologous series of Photoperiod 1 (Ppd1) genes. In this study, Ppd-A1 genomic sequences from the 5' UTR and promoter region were analysed in 104 accessions of six tetraploid wheat species (Triticum dicoccoides, T. dicoccum, T. turgidum, T. polonicum, T. carthlicum, T. durum) and 102 accessions of six hexaploid wheat species (T. aestivum, T. compactum, T. sphaerococcum, T. spelta, T. macha, T. vavilovii). This data was supplemented with in silico analysis of publicly available sequences from 46 to 193 accessions of diploid and tetraploid wheat, respectively. Analysis of a region of the Ppd-A1 promoter identified thirteen haplotypes, which were divided in two haplogroups. Distribution of the Ppd-A1 haplogroups and haplotypes in wheat species, and their geographical distributions were analysed. Polymerase chain reaction combined with a heteroduplex mobility assay was subsequently used to efficiently discriminate between Ppd-A1 alleles, allowing identification of the Ppd-A1b haplotypes and haplogroups. The causes of anomalous migration of Ppd-A1 heteroduplexes in gels were found to be the localization of mismatches relative to the center of fragment, the cumulative effect of neighbouring polymorphic sites, and the location of mismatches within A/T-tracts. Analysis of the Ppd-A1 5' UTR in hexaploid wheat revealed a novel mutation within the "photoperiod critical" region in a subset of T. compactum accessions. This putative photoperiod insensitive allele (designated Ppd-A1a.4) includes a 684bp deletion which spans region in common with deletions previously identified in other photoperiod insensitive Ppd1 alleles. PMID:25851614

  19. Structural Analysis of the Wheat Genes Encoding NADH-Dependent Glutamine-2-oxoglutarate Amidotransferases and Correlation with Grain Protein Content

    PubMed Central

    Nigro, Domenica; Gu, Yong Q.; Huo, Naxin; Marcotuli, Ilaria; Blanco, Antonio; Gadaleta, Agata; Anderson, Olin D.

    2013-01-01

    Background Nitrogen uptake and the efficient absorption and metabolism of nitrogen are essential elements in attempts to breed improved cereal cultivars for grain or silage production. One of the enzymes related to nitrogen metabolism is glutamine-2-oxoglutarate amidotransferase (GOGAT). Together with glutamine synthetase (GS), GOGAT maintains the flow of nitrogen from NH4+ into glutamine and glutamate, which are then used for several aminotransferase reactions during amino acid synthesis. Results The aim of the present work was to identify and analyse the structure of wheat NADH-GOGAT genomic sequences, and study the expression in two durum wheat cultivars characterized by low and high kernel protein content. The genomic sequences of the three homoeologous A, B and D NADH-GOGAT genes were obtained for hexaploid Triticum aestivum and the tetraploid A and B genes of Triticum turgidum ssp. durum. Analysis of the gene sequences indicates that all wheat NADH-GOGAT genes are composed of 22 exons and 21 introns. The three hexaploid wheat homoeologous genes have high conservation of sequence except intron 13 which shows differences in both length and sequence. A comparative analysis of sequences among di- and mono-cotyledonous plants shows both regions of high conservation and of divergence. qRT-PCR performed with the two durum wheat cvs Svevo and Ciccio (characterized by high and low protein content, respectively) indicates different expression levels of the two NADH-GOGAT-3A and NADH-GOGAT-3B genes. Conclusion The three hexaploid wheat homoeologous NADH-GOGAT gene sequences are highly conserved consistent with the key metabolic role of this gene. However, the dicot and monocot amino acid sequences show distinctive patterns, particularly in the transit peptide, the exon 1617 junction, and the C-terminus. The lack of conservation in the transit peptide may indicate subcellular differences between the two plant divisions - while the sequence conservation within enzyme functional domains remains high. Higher expression levels of NADH-GOGAT are associated with higher grain protein content in two durum wheats. PMID:24069228

  20. Recurrent Deletions of Puroindoline Genes at the Grain Hardness Locus in Four Independent Lineages of Polyploid Wheat1[W][OA

    PubMed Central

    Li, Wanlong; Huang, Li; Gill, Bikram S.

    2008-01-01

    Polyploidy is known to induce numerous genetic and epigenetic changes but little is known about their physiological bases. In wheat, grain texture is mainly determined by the Hardness (Ha) locus consisting of genes Puroindoline a (Pina) and b (Pinb). These genes are conserved in diploid progenitors but were deleted from the A and B genomes of tetraploid Triticum turgidum (AB). We now report the recurrent deletions of Pina-Pinb in other lineages of polyploid wheat. We analyzed the Ha haplotype structure in 90 diploid and 300 polyploid accessions of Triticum and Aegilops spp. Pin genes were conserved in all diploid species and deletion haplotypes were detected in all polyploid Triticum and most of the polyploid Aegilops spp. Two Pina-Pinb deletion haplotypes were found in hexaploid wheat (Triticum aestivum; ABD). Pina and Pinb were eliminated from the G genome, but maintained in the A genome of tetraploid Triticum timopheevii (AG). Subsequently, Pina and Pinb were deleted from the A genome but retained in the Am genome of hexaploid Triticum zhukovskyi (AmAG). Comparison of deletion breakpoints demonstrated that the Pina-Pinb deletion occurred independently and recurrently in the four polyploid wheat species. The implications of Pina-Pinb deletions for polyploid-driven evolution of gene and genome and its possible physiological significance are discussed. PMID:18024553

  1. Proteomic Approach to Identify Nuclear Proteins in Wheat Grain.

    PubMed

    Bancel, Emmanuelle; Bonnot, Titouan; Davanture, Marlne; Branlard, Grard; Zivy, Michel; Martre, Pierre

    2015-10-01

    The nuclear proteome of the grain of the two cultivated wheat species Triticum aestivum (hexaploid wheat; genomes A, B, and D) and T. monococcum (diploid wheat; genome A) was analyzed in two early stages of development using shotgun-based proteomics. A procedure was optimized to purify nuclei, and an improved protein sample preparation was developed to efficiently remove nonprotein substances (starch and nucleic acids). A total of 797 proteins corresponding to 528 unique proteins were identified, 36% of which were classified in functional groups related to DNA and RNA metabolism. A large number (107 proteins) of unknown functions and hypothetical proteins were also found. Some identified proteins may be multifunctional and may present multiple localizations. On the basis of the MS/MS analysis, 368 proteins were present in the two species, and in two stages of development, some qualitative differences between species and stages of development were also found. All of these data illustrate the dynamic function of the grain nucleus in the early stages of development. PMID:26228564

  2. Mapping of main and epistatic effect QTLs associated to grain protein and gluten strength using a RIL population of durum wheat.

    PubMed

    Conti, Veronica; Roncallo, Pablo F; Beaufort, Valeria; Cervigni, Gerardo L; Miranda, Ruben; Jensen, Carlos A; Echenique, Viviana C

    2011-08-01

    Quality, specifically protein content and gluten strength are among the main objectives of a durum wheat breeding program. The aim of this work was to validate quantitative trait loci (QTLs) associated with grain protein content (GPC) and gluten strength measured by SDS sedimentation volume (SV) and to find additional QTLs expressed in Argentinean environments. Also, epistatic QTL and QTL x environmental interactions were analyzed. A mapping population of 93 RILs derived from the cross UC1113 x Kofa showing extreme values in gluten quality was used. Phenotypic data were collected along six environments (three locations, two years). Main effect QTLs associated with GPC were found in equivalent positions in two environments on chromosomes 3BS (R(2)=21.0-21.6%) and 7BL (R(2)=12.1-13%), and in one environment on chromosomes 1BS, 2AL, 2BS, 3BL, 4AL, 5AS, 5BL and 7AS. The most important and stable QTL affecting SV was located on chromosome 1BL (Glu-B1) consistently detected over the six environments (R(2)=20.9- 54.2%). Additional QTLs were found in three environments on chromosomes 6AL (R(2)=6.4-12.5%), and in two environments on chromosomes 6BL (R(2)=11.5-12.1%), 7AS (R(2)=8.2-10.2%) and 4BS (R(2)=11-16.4%). In addition, pleiotropic effects were found affecting grain yield, test weight, thousand-kernel-weight and days to heading in some of these QTLs. Epistatic QTLs and QTL x environment interactions were found for both quality traits, mostly for GPC. The flanking markers of the QTLs detected in this work could be efficient tools to select superior genotypes for the mentioned traits. PMID:21523429

  3. Novel genetic variants of GA-insensitive Rht-1 genes in hexaploid wheat and their potential agronomic value.

    PubMed

    Tan, Mui-Keng; Koval, Jason; Ghalayini, Aida

    2013-01-01

    This study has found numerous novel genetic variants of GA-insensitive dwarfing genes with potential agricultural value for crop improvement. The cultivar, Spica is a tall genotype and possesses the wild-type genes of Rht-A1a, Rht-B1a and Rht-D1a. The cultivar Quarrion possesses a null mutant in the DELLA motif in each of the 3 genomes. This is a first report of a null mutant of Rht-A1. In addition, novel null mutants which differ from reported null alleles of Rht-B1b, Rht-B1e and Rht-D1b have been found in Quarrion, Carnamah and Whistler. The accession, Aus1408 has an allele of Rht-B1 with a mutation in the conserved 'TVHYNP' N-terminal signal binding domain with possible implications on its sensitivity to GA. Mutations in the conserved C-terminal GRAS domain of Rht-A1 alleles with possible effects on expression have been found in WW1842, Quarrion and Drysdale. Genetic variants with putative spliceosomal introns in the GRAS domain have been found in all accessions except Spica. Genome-specific cis-sequences about 124 bp upstream of the start codon of the Rht-1 gene have been identified for each of the three genomes. PMID:23894524

  4. Novel Genetic Variants of GA-Insensitive Rht-1 Genes in Hexaploid Wheat and Their Potential Agronomic Value

    PubMed Central

    Tan, Mui-Keng; Koval, Jason; Ghalayini, Aida

    2013-01-01

    This study has found numerous novel genetic variants of GA-insensitive dwarfing genes with potential agricultural value for crop improvement. The cultivar, Spica is a tall genotype and possesses the wild-type genes of Rht-A1a, Rht-B1a and Rht-D1a. The cultivar Quarrion possesses a null mutant in the DELLA motif in each of the 3 genomes. This is a first report of a null mutant of Rht-A1. In addition, novel null mutants which differ from reported null alleles of Rht-B1b, Rht-B1e and Rht-D1b have been found in Quarrion, Carnamah and Whistler. The accession, Aus1408 has an allele of Rht-B1 with a mutation in the conserved TVHYNP N-terminal signal binding domain with possible implications on its sensitivity to GA. Mutations in the conserved C-terminal GRAS domain of Rht-A1 alleles with possible effects on expression have been found in WW1842, Quarrion and Drysdale. Genetic variants with putative spliceosomal introns in the GRAS domain have been found in all accessions except Spica. Genome-specific cis-sequences about 124 bp upstream of the start codon of the Rht-1 gene have been identified for each of the three genomes. PMID:23894524

  5. Wheat Lipids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article is a chapter of a book entitled Wheat: Chemistry and Technology, the 4th edition, K. Khan and P.R. Shewry (eds.), to be published in 2007 following the 3rd edition, Y. Pomeranz (ed.), published in 1988 by AACC International Inc., St. Paul, MN. The chapter covers the subject area of wh...

  6. Al-Induced, 51-Kilodalton, Membrane-Bound Proteins Are Associated with Resistance to Al in a Segregating Population of Wheat.

    PubMed Central

    Taylor, G. J.; Basu, A.; Basu, U.; Slaski, J. J.; Zhang, G.; Good, A.

    1997-01-01

    Incorporation of 35S into protein is reduced by exposure to Al in wheat (Triticum aestivum), but the effects are genotype-specific. Exposure to 10 to 75 [mu]M Al had little effect on 35S incorporation into total protein, nuclear and mitochondrial protein, microsomal protein, and cytosolic protein in the Al-resistant cultivar PT741. In contrast, 10 [mu]M Al reduced incorporation by 21 to 38% in the Al-sensitive cultivar Katepwa, with effects becoming more pronounced (31-62%) as concentrations of Al increased. We previously reported that a pair of 51-kD membrane-bound proteins accumulated in root tips of PT741 under conditions of Al stress. We now report that the 51-kD band is labeled with 35S after 24 h of exposure to 75 [mu]M Al. The specific induction of the 51-kD band in PT741 suggested a potential role of one or both of these proteins in mediating resistance to Al. Therefore, we analyzed their expression in single plants from an F2 population arising from a cross between the PT741 and Katepwa cultivars. Accumulation of 1,3-[beta]-glucans (callose) in root tips after 24 h of exposure to 100 [mu]M Al indicated that this population segregated for Al resistance in about a 3:1 ratio. A close correlation between resistance to Al (low callose content of root tips) and accumulation of the 51-kD band was observed, indicating that at least one of these proteins cosegregates with the Al-resistance phenotype. As a first step in identifying a possible function, we have demonstrated that the 51-kD band is most clearly associated with the tonoplast. Whereas Al has been reported to stimulate the activity of the tonoplast H+-ATPase and H+-PPase, antibodies raised against these proteins did not cross-react with the 51-kD band. Efforts are now under way to purify this protein from tonoplast-enriched fractions. PMID:12223709

  7. The tae-miR408-Mediated Control of TaTOC1 Genes Transcription Is Required for the Regulation of Heading Time in Wheat1[OPEN

    PubMed Central

    Zhao, Xiang Yu; Hong, Po; Chen, Xiang Bin; Ye, Xing Guo; Pan, Yan You; Wang, Jian

    2016-01-01

    Timing of flowering is not only an interesting topic in developmental biology, but it also plays a significant role in agriculture for its effects on the maturation time of seed. The hexaploid wheat (Triticum aestivum) is one of the most important crop species whose flowering time, i.e. heading time, greatly influences yield. However, it remains unclear whether and how microRNAs regulate heading time in it. In our current study, we identified the tae-miR408 in wheat and its targets in vivo, including Triticum aestivum TIMING OF CAB EXPRESSION-A1 (TaTOC-A1), TaTOC-B1, and TaTOC-D1. The tae-miR408 levels were reciprocal to those of TaTOC1s under long-day and short-day conditions. Wheat plants with a knockdown of TaTOC1s via RNA interference and overexpression of tae-miR408 showed early-heading phenotype. Furthermore, TaTOC1s expression was down-regulated by the tae-miR408 in the hexaploid wheat. In addition, other important agronomic traits in wheat, such as plant height and flag leaf angle, were regulated by both tae-miR408 and TaTOC1s. Thus, our results suggested that the tae-miR408 functions in the wheat heading time by mediating TaTOC1s expression, and the study provides important new information on the mechanism underlying heading time regulation in wheat. PMID:26768600

  8. The tae-miR408-Mediated Control of TaTOC1 Genes Transcription Is Required for the Regulation of Heading Time in Wheat.

    PubMed

    Zhao, Xiang Yu; Hong, Po; Wu, Ji Yun; Chen, Xiang Bin; Ye, Xing Guo; Pan, Yan You; Wang, Jian; Zhang, Xian Sheng

    2016-03-01

    Timing of flowering is not only an interesting topic in developmental biology, but it also plays a significant role in agriculture for its effects on the maturation time of seed. The hexaploid wheat (Triticum aestivum) is one of the most important crop species whose flowering time, i.e. heading time, greatly influences yield. However, it remains unclear whether and how microRNAs regulate heading time in it. In our current study, we identified the tae-miR408 in wheat and its targets in vivo, including Triticum aestivum TIMING OF CAB EXPRESSION-A1 (TaTOC-A1), TaTOC-B1, and TaTOC-D1. The tae-miR408 levels were reciprocal to those of TaTOC1s under long-day and short-day conditions. Wheat plants with a knockdown of TaTOC1s via RNA interference and overexpression of tae-miR408 showed early-heading phenotype. Furthermore, TaTOC1s expression was down-regulated by the tae-miR408 in the hexaploid wheat. In addition, other important agronomic traits in wheat, such as plant height and flag leaf angle, were regulated by both tae-miR408 and TaTOC1s. Thus, our results suggested that the tae-miR408 functions in the wheat heading time by mediating TaTOC1s expression, and the study provides important new information on the mechanism underlying heading time regulation in wheat. PMID:26768600

  9. Genetic transformation of mature embryos of bread (T. aestivum) and pasta (T. durum) wheat genotypes.

    PubMed

    Moghaieb, Reda E A; El-Arabi, Nagwa I; Momtaz, Osama A; Youssef, Sawsan S; Soliman, Mohamed H

    2010-01-01

    The objective of the present study is to develop an efficient protocol for regeneration of transgenic wheat plants using Agrobacterium- mediated transformation of mature embryos of hexaploid bread wheat (Triticum aestivum) and tetraploid pasta wheat (Triticum durum). The data indicated that embryogenic calli were formed within 7 days in the presence of 2 mgl-1 2,4-D. Adventitious shoots emerged from the embryonic calli in the presence of 2 mgl-1 BA. Shoot regeneration frequency varied between wheat cultivars according to their genetic background differences. Regeneration frequency was higher in the cultivar Gemmiza 10 (95 %) compared with the other cultivars tested. Mature embryos derived callus of the cultivars Gemmiza 10 and Gemmiza 9 were co-cultivated with A. tumefaciens strain LBA4404 harboring a binary vector pBI-121 containing the neomycin phosphotransferase-II gene (npt-II). The resulted putative transgenic plantlets were able to grow on kanamycin containing medium. A successful integration of the transgene was confirmed by analyzing the T0 plantlets using Southern hybridization and PCR amplification. The gus gene expression can be detected only in the transgenic plants. The reported protocol is reproducible and can be used to regenerate transgenic wheat plants expressing the genes present in A. tumifaciens binary vectors. PMID:21865876

  10. Identifying Quantitative Trait Loci For Three Physiological Traits And Grain Yield In A Recombination Inbred Line Population Of Wheat (Triticum aestivum L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drought can severely limit wheat production and is difficult to address through genetic improvement. The genetic mechanisms controlling drought related traits are ambiguous and poorly understood. The objective of this study is to identify QTL and molecular markers that are associated with canopy tem...

  11. Tan spot susceptibility governed by the Tsn1 locus and race-nonspecific resistance quantitative trait loci in a population derived from the wheat lines Salamouni and Katepwa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat-tan spot interactions are known to have an inverse gene-for-gene relationship where pathogen-produced necrotrophic effectors are recognized by host sensitivity genes to cause susceptibility. However, broad-spectrum non race-specific resistance quantitative trait loci (QTL) that do not conform...

  12. Identification of genes bordering breakpoints of the pericentric inversions on 2B, 4B, and 5A in bread wheat (Triticum aestivum L.).

    PubMed

    Ma, Jian; Gao, Shang; Stiller, Jiri; Jiang, Qian-Tao; Lan, Xiu-Jin; Liu, Ya-Xi; Pu, Zhi-En; Wang, Jirui; Wei, Yuming; Zheng, You-Liang

    2015-08-01

    Chromosome translocation is an important driving force in shaping genomes during evolution. Detailed knowledge of chromosome translocations in a given species and its close relatives should increase the efficiency and precision of chromosome engineering in crop improvement. To identify genes flanking the breakpoints of translocations and inversions as a step toward identifying breakpoints in bread wheat, we systematically analysed genes in the Brachypodium genome against wheat survey sequences and bin-mapped ESTs (expressed sequence tags) derived from the hexaploid wheat genotype 'Chinese Spring'. In addition to those well-known translocations between group 4, 5, and 7 chromosomes, this analysis identified genes flanking the three pericentric inversions on chromosomes 2B, 4B, and 5A. However, numerous chromosomal rearrangements reported in early studies could not be confirmed. The genes flanking the breakpoints reported in this study are valuable for isolating these breakpoints. PMID:26356308

  13. Genome-Wide Linkage Mapping of QTL for Adult-Plant Resistance to Stripe Rust in a Chinese Wheat Population Linmai 2 Zhong 892.

    PubMed

    Liu, Jindong; He, Zhonghu; Wu, Ling; Bai, Bin; Wen, Weie; Xie, Chaojie; Xia, Xianchun

    2015-01-01

    Stripe rust is one of the most devastating diseases of wheat (Triticum aestivum) worldwide. Adult-plant resistance (APR) is an efficient approach to provide long-term protection of wheat from the disease. The Chinese winter wheat cultivar Zhong 892 has a moderate level of APR to stripe rust in the field. To determine the inheritance of the APR resistance in this cultivar, 273 F6 recombinant inbred lines (RILs) were developed from a cross between Linmai 2 and Zhong 892. The RILs were evaluated for maximum disease severity (MDS) in two sites during the 2011-2012, 2012-2013 and 2013-2014 cropping seasons, providing data for five environments. Illumina 90k SNP (single nucleotide polymorphism) chips were used to genotype the RILs and their parents. Composite interval mapping (CIM) detected eight QTL, namely QYr.caas-2AL, QYr.caas-2BL.3, QYr.caas-3AS, QYr.caas-3BS, QYr.caas-5DL, QYr.caas-6AL, QYr.caas-7AL and QYr.caas-7DS.1, respectively. All except QYr.caas-2BL.3 resistance alleles were contributed by Zhong 892. QYr.caas-3AS and QYr.caas-3BS conferred stable resistance to stripe rust in all environments, explaining 6.2-17.4% and 5.0-11.5% of the phenotypic variances, respectively. The genome scan of SNP sequences tightly linked to QTL for APR against annotated proteins in wheat and related cereals genomes identified two candidate genes (autophagy-related gene and disease resistance gene RGA1), significantly associated with stripe rust resistance. These QTL and their closely linked SNP markers, in combination with kompetitive allele specific PCR (KASP) technology, are potentially useful for improving stripe rust resistances in wheat breeding. PMID:26714310

  14. Genome-Wide Linkage Mapping of QTL for Adult-Plant Resistance to Stripe Rust in a Chinese Wheat Population Linmai 2 × Zhong 892

    PubMed Central

    Liu, Jindong; He, Zhonghu; Wu, Ling; Bai, Bin; Wen, Weie; Xie, Chaojie; Xia, Xianchun

    2015-01-01

    Stripe rust is one of the most devastating diseases of wheat (Triticum aestivum) worldwide. Adult-plant resistance (APR) is an efficient approach to provide long-term protection of wheat from the disease. The Chinese winter wheat cultivar Zhong 892 has a moderate level of APR to stripe rust in the field. To determine the inheritance of the APR resistance in this cultivar, 273 F6 recombinant inbred lines (RILs) were developed from a cross between Linmai 2 and Zhong 892. The RILs were evaluated for maximum disease severity (MDS) in two sites during the 2011–2012, 2012–2013 and 2013–2014 cropping seasons, providing data for five environments. Illumina 90k SNP (single nucleotide polymorphism) chips were used to genotype the RILs and their parents. Composite interval mapping (CIM) detected eight QTL, namely QYr.caas-2AL, QYr.caas-2BL.3, QYr.caas-3AS, QYr.caas-3BS, QYr.caas-5DL, QYr.caas-6AL, QYr.caas-7AL and QYr.caas-7DS.1, respectively. All except QYr.caas-2BL.3 resistance alleles were contributed by Zhong 892. QYr.caas-3AS and QYr.caas-3BS conferred stable resistance to stripe rust in all environments, explaining 6.2–17.4% and 5.0–11.5% of the phenotypic variances, respectively. The genome scan of SNP sequences tightly linked to QTL for APR against annotated proteins in wheat and related cereals genomes identified two candidate genes (autophagy-related gene and disease resistance gene RGA1), significantly associated with stripe rust resistance. These QTL and their closely linked SNP markers, in combination with kompetitive allele specific PCR (KASP) technology, are potentially useful for improving stripe rust resistances in wheat breeding. PMID:26714310

  15. Winter and Specialty Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The two main commercial types of wheat are durum (Triticum durum L., 2n=4x= 28) and common (T. aestivum L, 2n=6x=42.) wheat, the latter being the more widely grown. Wheat has three growth habits, namely winter (wheats grown over the winter months that require vernalization and can withstand prolong...

  16. The chloroplast genome of the hexaploid Spartina maritima (Poaceae, Chloridoideae): Comparative analyses and molecular dating.

    PubMed

    Rousseau-Gueutin, M; Bellot, S; Martin, G E; Boutte, J; Chelaifa, H; Lima, O; Michon-Coudouel, S; Naquin, D; Salmon, A; Ainouche, K; Ainouche, M

    2015-12-01

    The history of many plant lineages is complicated by reticulate evolution with cases of hybridization often followed by genome duplication (allopolyploidy). In such a context, the inference of phylogenetic relationships and biogeographic scenarios based on molecular data is easier using haploid markers like chloroplast genome sequences. Hybridization and polyploidization occurred recurrently in the genus Spartina (Poaceae, Chloridoideae), as illustrated by the recent formation of the invasive allododecaploid S. anglica during the 19th century in Europe. Until now, only a few plastid markers were available to explore the history of this genus and their low variability limited the resolution of species relationships. We sequenced the complete chloroplast genome (plastome) of S. maritima, the native European parent of S. anglica, and compared it to the plastomes of other Poaceae. Our analysis revealed the presence of fast-evolving regions of potential taxonomic, phylogeographic and phylogenetic utility at various levels within the Poaceae family. Using secondary calibrations, we show that the tetraploid and hexaploid lineages of Spartina diverged 6-10 my ago, and that the two parents of the invasive allopolyploid S. anglica separated 2-4 my ago via long distance dispersal of the ancestor of S. maritima over the Atlantic Ocean. Finally, we discuss the meaning of divergence times between chloroplast genomes in the context of reticulate evolution. PMID:26182838

  17. Exploring and Mobilizing the Gene Bank Biodiversity for Wheat Improvement.

    PubMed

    Sehgal, Deepmala; Vikram, Prashant; Sansaloni, Carolina Paola; Ortiz, Cynthia; Pierre, Carolina Saint; Payne, Thomas; Ellis, Marc; Amri, Ahmed; Petroli, Csar Daniel; Wenzl, Peter; Singh, Sukhwinder

    2015-01-01

    Identifying and mobilizing useful genetic variation from germplasm banks to breeding programs is an important strategy for sustaining crop genetic improvement. The molecular diversity of 1,423 spring bread wheat accessions representing major global production environments was investigated using high quality genotyping-by-sequencing (GBS) loci, and gene-based markers for various adaptive and quality traits. Mean diversity index (DI) estimates revealed synthetic hexaploids to be genetically more diverse (DI= 0.284) than elites (DI = 0.267) and landraces (DI = 0.245). GBS markers discovered thousands of new SNP variations in the landraces which were well known to be adapted to drought (1273 novel GBS SNPs) and heat (4473 novel GBS SNPs) stress environments. This may open new avenues for pre-breeding by enriching the elite germplasm with novel alleles for drought and heat tolerance. Furthermore, new allelic variation for vernalization and glutenin genes was also identified from 47 landraces originating from Iraq, Iran, India, Afghanistan, Pakistan, Uzbekistan and Turkmenistan. The information generated in the study has been utilized to select 200 diverse gene bank accessions to harness their potential in pre-breeding and for allele mining of candidate genes for drought and heat stress tolerance, thus channeling novel variation into breeding pipelines. This research is part of CIMMYT's ongoing 'Seeds of Discovery' project visioning towards the development of high yielding wheat varieties that address future challenges from climate change. PMID:26176697

  18. Exploring and Mobilizing the Gene Bank Biodiversity for Wheat Improvement

    PubMed Central

    Sehgal, Deepmala; Vikram, Prashant; Sansaloni, Carolina Paola; Ortiz, Cynthia; Pierre, Carolina Saint; Payne, Thomas; Ellis, Marc; Amri, Ahmed; Petroli, César Daniel; Wenzl, Peter; Singh, Sukhwinder

    2015-01-01

    Identifying and mobilizing useful genetic variation from germplasm banks to breeding programs is an important strategy for sustaining crop genetic improvement. The molecular diversity of 1,423 spring bread wheat accessions representing major global production environments was investigated using high quality genotyping-by-sequencing (GBS) loci, and gene-based markers for various adaptive and quality traits. Mean diversity index (DI) estimates revealed synthetic hexaploids to be genetically more diverse (DI= 0.284) than elites (DI = 0.267) and landraces (DI = 0.245). GBS markers discovered thousands of new SNP variations in the landraces which were well known to be adapted to drought (1273 novel GBS SNPs) and heat (4473 novel GBS SNPs) stress environments. This may open new avenues for pre-breeding by enriching the elite germplasm with novel alleles for drought and heat tolerance. Furthermore, new allelic variation for vernalization and glutenin genes was also identified from 47 landraces originating from Iraq, Iran, India, Afghanistan, Pakistan, Uzbekistan and Turkmenistan. The information generated in the study has been utilized to select 200 diverse gene bank accessions to harness their potential in pre-breeding and for allele mining of candidate genes for drought and heat stress tolerance, thus channeling novel variation into breeding pipelines. This research is part of CIMMYT’s ongoing ‘Seeds of Discovery’ project visioning towards the development of high yielding wheat varieties that address future challenges from climate change. PMID:26176697

  19. Adverse Effects of Wheat Gluten.

    PubMed

    Koning, Frits

    2015-01-01

    Man began to consume cereals approximately 10,000 years ago when hunter-gatherers settled in the fertile golden crescent in the Middle East. Gluten has been an integral part of the Western type of diet ever since, and wheat consumption is also common in the Middle East, parts of India and China as well as Australia and Africa. In fact, the food supply in the world heavily depends on the availability of cereal-based food products, with wheat being one of the largest crops in the world. Part of this is due to the unique properties of wheat gluten, which has a high nutritional value and is crucial for the preparation of high-quality dough. In the last 10 years, however, wheat and gluten have received much negative attention. Many believe that it is inherently bad for our health and try to avoid consumption of gluten-containing cereals; a gluten-low lifestyle so to speak. This is fueled by a series of popular publications like Wheat Belly; Lose the Wheat, Lose the Weight, and Find Your Path Back to Health. However, in reality, there is only one condition where gluten is definitively the culprit: celiac disease (CD), affecting approximately 1% of the population in the Western world. Here, I describe the complexity of the cereals from which gluten is derived, the special properties of gluten which make it so widely used in the food industry, the basis for its toxicity in CD patients and the potential for the development of safe gluten and alternatives to the gluten-free diet. PMID:26606684

  20. Adverse Effects of Wheat Gluten.

    TOXLINE Toxicology Bibliographic Information

    Koning F

    2015-01-01

    Man began to consume cereals approximately 10,000 years ago when hunter-gatherers settled in the fertile golden crescent in the Middle East. Gluten has been an integral part of the Western type of diet ever since, and wheat consumption is also common in the Middle East, parts of India and China as well as Australia and Africa. In fact, the food supply in the world heavily depends on the availability of cereal-based food products, with wheat being one of the largest crops in the world. Part of this is due to the unique properties of wheat gluten, which has a high nutritional value and is crucial for the preparation of high-quality dough. In the last 10 years, however, wheat and gluten have received much negative attention. Many believe that it is inherently bad for our health and try to avoid consumption of gluten-containing cereals; a gluten-low lifestyle so to speak. This is fueled by a series of popular publications like Wheat Belly; Lose the Wheat, Lose the Weight, and Find Your Path Back to Health. However, in reality, there is only one condition where gluten is definitively the culprit: celiac disease (CD), affecting approximately 1% of the population in the Western world. Here, I describe the complexity of the cereals from which gluten is derived, the special properties of gluten which make it so widely used in the food industry, the basis for its toxicity in CD patients and the potential for the development of safe gluten and alternatives to the gluten-free diet.

  1. Population.

    ERIC Educational Resources Information Center

    King, Pat; Landahl, John

    This pamphlet has been prepared in response to a new problem, a rapidly increasing population, and a new need, population education. It is designed to help teachers provide their students with some basic population concepts with stress placed on the elements of decision making. In the first section of the pamphlet, some of the basic concepts of…

  2. Genomic in situ hybridization reveals both auto- and allopolyploid origins of different North and Central American hexaploid potato (Solanum sect. Petota) species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wild potato (Solanum section Petota) species contain diploids (2n = 2x = 24), tetraploids (2n = 4x = 48), hexaploids (2n = 6x = 72), and rare triploids and pentaploids. Determination of the type of polyploidy and the development of the genome concept for section Petota classically was based on the a...

  3. Registration of Babe wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soft white wheat (Triticum aestivum L.) is the predominant market class of wheat produced in the Pacific Northwest of the United States. Stripe rust (caused by Puccinia striiformis Westend f. sp. tritici) is a major foliar fungal disease problem for wheat cultivars grown in the region. The objective...

  4. Wheat Stripe Rust

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is a chapter on wheat stripe rust in a book entitled Wheat: Science and Trade. The chapter provides an overview on various aspects of wheat stripe rust and control, including distribution and epidemiology; origin and historical importance; taxonomy, lifecycle, and host range; genetic variati...

  5. Wheat: Science and Trade

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is for a book review of Wheat: science and trade, edited by B.F. Carver. The book provides an indepth review of wheat biology, production, breeding, processing, and trade and is organized in four sections. "Making of a Wheat Plant" reviews domestication, evolution, development, and molecular ...

  6. High-Density Genetic Linkage Map Construction and QTL Mapping of Grain Shape and Size in the Wheat Population Yanda1817 × Beinong6

    PubMed Central

    Wu, Qiu-Hong; Chen, Yong-Xing; Zhou, Sheng-Hui; Fu, Lin; Chen, Jiao-Jiao; Xiao, Yao; Zhang, Dong; Ouyang, Shu-Hong; Zhao, Xiao-Jie; Cui, Yu; Zhang, De-Yun; Liang, Yong; Wang, Zhen-Zhong; Xie, Jing-Zhong; Qin, Jin-Xia; Wang, Guo-Xin; Li, De-Lin; Huang, Yin-Lian; Yu, Mei-Hua; Lu, Ping; Wang, Li-Li; Wang, Ling; Wang, Hao; Dang, Chen; Li, Jie; Zhang, Yan; Peng, Hui-Ru; Yuan, Cheng-Guo; You, Ming-Shan; Sun, Qi-Xin; Wang, Ji-Rui; Wang, Li-Xin; Luo, Ming-Cheng; Han, Jun; Liu, Zhi-Yong

    2015-01-01

    High-density genetic linkage maps are necessary for precisely mapping quantitative trait loci (QTLs) controlling grain shape and size in wheat. By applying the Infinium iSelect 9K SNP assay, we have constructed a high-density genetic linkage map with 269 F 8 recombinant inbred lines (RILs) developed between a Chinese cornerstone wheat breeding parental line Yanda1817 and a high-yielding line Beinong6. The map contains 2431 SNPs and 128 SSR & EST-SSR markers in a total coverage of 3213.2 cM with an average interval of 1.26 cM per marker. Eighty-eight QTLs for thousand-grain weight (TGW), grain length (GL), grain width (GW) and grain thickness (GT) were detected in nine ecological environments (Beijing, Shijiazhuang and Kaifeng) during five years between 2010–2014 by inclusive composite interval mapping (ICIM) (LOD≥2.5). Among which, 17 QTLs for TGW were mapped on chromosomes 1A, 1B, 2A, 2B, 3A, 3B, 3D, 4A, 4D, 5A, 5B and 6B with phenotypic variations ranging from 2.62% to 12.08%. Four stable QTLs for TGW could be detected in five and seven environments, respectively. Thirty-two QTLs for GL were mapped on chromosomes 1B, 1D, 2A, 2B, 2D, 3B, 3D, 4A, 4B, 4D, 5A, 5B, 6B, 7A and 7B, with phenotypic variations ranging from 2.62% to 44.39%. QGl.cau-2A.2 can be detected in all the environments with the largest phenotypic variations, indicating that it is a major and stable QTL. For GW, 12 QTLs were identified with phenotypic variations range from 3.69% to 12.30%. We found 27 QTLs for GT with phenotypic variations ranged from 2.55% to 36.42%. In particular, QTL QGt.cau-5A.1 with phenotypic variations of 6.82–23.59% was detected in all the nine environments. Moreover, pleiotropic effects were detected for several QTL loci responsible for grain shape and size that could serve as target regions for fine mapping and marker assisted selection in wheat breeding programs. PMID:25675376

  7. Population.

    ERIC Educational Resources Information Center

    International Planned Parenthood Federation, London (England).

    In an effort to help meet the growing interest and concern about the problems created by the rapid growth of population, The International Planned Parenthood Federation has prepared this booklet with the aim of assisting the study of the history and future trends of population growth and its impact on individual and family welfare, national,…

  8. Molecular Characterization of wheat stem rust races in Kenya

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stem or black rust caused by Puccinia graminis f. sp. tritici (Pgt) Erikss. & Henning causes severe losses to wheat (Triticum aestivum L.), historically threatening global wheat production. Characterizing prevalent isolates of Pgt would enhance the knowledge of population dynamics and evolution of t...

  9. QUANTITATIVE TRAIT LOCI FOR ALUMINUM RESISTANCE IN WHEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantitative trait loci (QTLs) for wheat resistance to aluminum (Al) toxicity were analyzed using simple sequence repeats (SSRs) in a population of 192 F6 recombinant inbred lines (RILs) derived from a cross between an Al-resistant cultivar, Atlas 66 and an Al-sensitive cultivar, Chisholm. Wheat rea...

  10. Aphid Feeding Activates Expression of a Transcriptome of Oxylipin-Based Defense Signals in Wheat Involved in Resistance to Herbivory

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Damage by the Russian wheat aphid (RWA), Diuraphis noxia, significantly reduces wheat and barley yields worldwide. In compatible interactions, virulent RWA populations flourish and susceptible plants suffer extensive leaf chlorophyll loss. In incompatible interactions, RWA reproduction and populatio...

  11. Inferring the contribution of sexual reproduction, migration and off-season survival to the temporal maintenance of microbial populations: a case study on the wheat fungal pathogen Puccinia striiformis f.sp. tritici.

    PubMed

    Ali, Sajid; Gladieux, Pierre; Rahman, Hidayatur; Saqib, Muhammad S; Fiaz, Muhammad; Ahmad, Habib; Leconte, Marc; Gautier, Anglique; Justesen, Annemarie F; Hovmller, Mogens S; Enjalbert, Jrme; de Vallavieille-Pope, Claude

    2014-02-01

    Understanding the mode of temporal maintenance of plant pathogens is an important domain of microbial ecology research. Due to the inconspicuous nature of microbes, their temporal maintenance cannot be studied directly through tracking individuals and their progeny. Here, we suggest a series of population genetic analyses on molecular marker variation in temporally spaced samples to infer about the relative contribution of sexual reproduction, off-season survival and migration to the temporal maintenance of pathogen populations. We used the proposed approach to investigate the temporal maintenance of wheat yellow rust pathogen, Puccinia striiformis f.sp. tritici (PST), in the Himalayan region of Pakistan. Multilocus microsatellite genotyping of PST isolates revealed high genotypic diversity and recombinant population structure across all locations, confirming the existence of sexual reproduction in this region. The genotypes were assigned to four genetic groups, revealing a clear differentiation between zones with and without Berberis spp., the alternate host of PST, with an additional subdivision within the Berberis zone. The lack of any differentiation between samples across two sampling years, and the very infrequent resampling of multilocus genotypes over years at a given location was consistent with limited over-year clonal survival, and a limited genetic drift. The off-season oversummering population in the Berberis zone, likely to be maintained locally, served as a source of migrants contributing to the temporal maintenance in the non-Berberis zone. Our study hence demonstrated the contribution of both sexual recombination and off-season oversummering survival to the temporal maintenance of the pathogen. These new insights into the population biology of PST highlight the general usefulness of the analytical approach proposed. PMID:24354737

  12. The Structure and Expression of the Wheat Starch Synthase III Gene. Motifs in the Expressed Gene Define the Lineage of the Starch Synthase III Gene Family1

    PubMed Central

    Li, Zhongyi; Mouille, Greg; Kosar-Hashemi, Behjat; Rahman, Sadequr; Clarke, Bryan; Gale, Kevin R.; Appels, Rudi; Morell, Matthew K.

    2000-01-01

    The endosperm of hexaploid wheat (Triticum aestivum [L.]) was shown to contain a high molecular weight starch synthase (SS) analogous to the product of the maize du1 gene, starch synthase III (SSIII; DU1). cDNA and genomic DNA sequences encoding wheat SSIII were isolated and characterized. The wheat SSIII cDNA is 5,346 bp long and contains an open reading frame that encodes a 1,628-amino acid polypeptide. A putative N-terminal transit peptide, a 436-amino acid C-terminal catalytic domain, and a central 470-amino acid SSIII-specific domain containing three regions of repeated amino acid similarity were identified in the wheat gene. A fourth region between the transit peptide and the SSIII-specific domain contains repeat motifs that are variable with respect to motif sequence and repeat number between wheat and maize. In dicots, this N-terminal region does not contain repeat motifs and is truncated. The gene encoding wheat SSIII, designated ss3, consists of 16 exons extending over 10 kb, and is located on wheat chromosome I. Expression of ss3 mRNA in wheat was detected in leaves, pre-anthesis florets, and from very early to middle stage of endosperm development. The entire N-terminal variable repeat region and the majority of the SSIII-specific domain are encoded on a single 2,703-bp exon. A gene encoding a class III SS from the Arabidopsis genome sequencing project shows a strongly conserved exon structure to the wheat ss3 gene, with the exception of the N-terminal region. The evolutionary relationships of the genes encoding monocot and dicot class III SSs are discussed. PMID:10859191

  13. A novel retrotransposon inserted in the dominant Vm-B1 allele confers spring growth habit in tetraploid wheat (Triticum turgidum L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat is traditionally divided into winter and spring wheat that either has or lacks a vernalization requirement. In this study, a doubled haploid (DH) population derived from a cross between two spring tetraploid wheat (Triticum turgidum L.) genotypes, durum Lebsock and Persian wheat accession PI...

  14. Induced mutations in the starch branching enzyme II (SBEII) genes increase amylose and resistant starch content in durum wheat

    PubMed Central

    Hazard, Brittany; Zhang, Xiaoqin; Colasuonno, Pasqualina; Uauy, Cristobal; Beckles, Diane M.; Dubcovsky, Jorge

    2016-01-01

    Starch is the largest component of the wheat (Triticum aestivum L.) grain and consists of approximately 70-80% amylopectin and 20-30% amylose. Amylopectin is a highly-branched, readily digested polysaccharide, whereas amylose has few branches and forms complexes that resist digestion and mimic dietary fiber (resistant starch). Down-regulation of the starch branching enzyme II (SBEII) gene by RNA interference (RNAi) was previously shown to increase amylose content in both hexaploid and tetraploid wheat. We generated ethyl methane sulphonate (EMS) mutants for the SBEIIa-A and SBEIIa-B homoeologs in the tetraploid durum wheat variety Kronos (T. turgidum ssp. durum L.). Single-gene mutants showed non-significant increases in amylose and resistant starch content, but a double mutant combining a SBEIIa-A knock-out mutation with a SBEIIa-B splice-site mutation showed a 22% increase in amylose content (P<0.0001) and a 115% increase in resistant starch content (P<0.0001). In addition, we obtained mutants for the A and B genome copies of the paralogous SBEIIb gene, mapped them 1-2 cM from SBEIIa, and generated double SBEIIa-SBEIIb mutants to study the effect of the SBEIIb gene in the absence of SBEIIa. These mutants are available to those interested in increasing amylose content and resistant starch in durum wheat. PMID:26924849

  15. De Novo Transcriptome Assembly and Analyses of Gene Expression during Photomorphogenesis in Diploid Wheat Triticum monococcum

    PubMed Central

    Naithani, Sushma; Sullivan, Chris; Preece, Justin; Tiwari, Vijay K.; Elser, Justin; Leonard, Jeffrey M.; Sage, Abigail; Gresham, Cathy; Kerhornou, Arnaud; Bolser, Dan; McCarthy, Fiona; Kersey, Paul; Lazo, Gerard R.; Jaiswal, Pankaj

    2014-01-01

    Background Triticum monococcum (2n) is a close ancestor of T. urartu, the A-genome progenitor of cultivated hexaploid wheat, and is therefore a useful model for the study of components regulating photomorphogenesis in diploid wheat. In order to develop genetic and genomic resources for such a study, we constructed genome-wide transcriptomes of two Triticum monococcum subspecies, the wild winter wheat T. monococcum ssp. aegilopoides (accession G3116) and the domesticated spring wheat T. monococcum ssp. monococcum (accession DV92) by generating de novo assemblies of RNA-Seq data derived from both etiolated and green seedlings. Principal Findings The de novo transcriptome assemblies of DV92 and G3116 represent 120,911 and 117,969 transcripts, respectively. We successfully mapped ?90% of these transcripts from each accession to barley and ?95% of the transcripts to T. urartu genomes. However, only ?77% transcripts mapped to the annotated barley genes and ?85% transcripts mapped to the annotated T. urartu genes. Differential gene expression analyses revealed 22% more light up-regulated and 35% more light down-regulated transcripts in the G3116 transcriptome compared to DV92. The DV92 and G3116 mRNA sequence reads aligned against the reference barley genome led to the identification of ?500,000 single nucleotide polymorphism (SNP) and ?22,000 simple sequence repeat (SSR) sites. Conclusions De novo transcriptome assemblies of two accessions of the diploid wheat T. monococcum provide new empirical transcriptome references for improving Triticeae genome annotations, and insights into transcriptional programming during photomorphogenesis. The SNP and SSR sites identified in our analysis provide additional resources for the development of molecular markers. PMID:24821410

  16. Transcriptome analysis of an mvp mutant reveals important changes in global gene expression and a role for methyl jasmonate in vernalization and flowering in wheat

    PubMed Central

    Diallo, Amadou Oury; Agharbaoui, Zahra; Sarhan, Fathey

    2014-01-01

    The einkorn wheat mutant mvp-1 (maintained vegetative phase 1) has a non-flowering phenotype caused by deletions including, but not limited to, the genes CYS, PHYC, and VRN1. However, the impact of these deletions on global gene expression is still unknown. Transcriptome analysis showed that these deletions caused the upregulation of several pathogenesis-related (PR) and jasmonate-responsive genes. These results suggest that jasmonates may be involved in flowering and vernalization in wheat. To test this hypothesis, jasmonic acid (JA) and methyl jasmonate (MeJA) content in mvp and wild-type plants was measured. The content of JA was comparable in all plants, whereas the content of MeJA was higher by more than 6-fold in mvp plants. The accumulation of MeJA was also observed in vernalization-sensitive hexaploid winter wheat during cold exposure. This accumulation declined rapidly once plants were deacclimated under floral-inductive growth conditions. This suggests that MeJA may have a role in floral transition. To confirm this result, we treated vernalization-insensitive spring wheat with MeJA. The treatment delayed flowering with significant downregulation of both TaVRN1 and TaFT1 genes. These data suggest a role for MeJA in modulating vernalization and flowering time in wheat. PMID:24683181

  17. How diverse a farmer-managed wheat landrace can be?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phenotypic variation in phenological, quantitative and qualitative traits was assessed in geographically-isolated, farmer-managed wheat landrace populations grown under subsistence farming conditions. Several multivariate, genetic diversity and sequential equation modeling procedures were used to bu...

  18. Non-celiac wheat sensitivity: differential diagnosis, triggers and implications.

    PubMed

    Schuppan, Detlef; Pickert, Geethanjali; Ashfaq-Khan, Muhammad; Zevallos, Victor

    2015-06-01

    Non allergy-non-celiac wheat sensitivity (NCWS) has become a common and often overrated diagnosis. Skepticism mainly relates to patients with prominent intestinal symptoms in the absence of general or intestinal signs of inflammation. There is consensus that the major wheat sensitivities, celiac disease and wheat allergy, have to be ruled out which may be difficult for wheat allergy. The non-inflammatory intolerances to carbohydrates, mainly lactose and FODMAPs (fermentable oligi-, di-, monosaccharides and polyols), which cause bloating or diarrhoea, can usually be excluded clinically or by simple tests. Recent studies and experimental data strongly indicate that NCWS exists in a substantial proportion of the population, that it is an innate immune reaction to wheat and that patients often present with extraintestinal symptoms, such as worsening of an underlying inflammatory disease in clear association with wheat consumption. Wheat amylase-trypsin inhibitors (ATIs) have been identified as the most likely triggers of NCWS. They are highly protease resistant and activate the toll-like receptor 4 (TLR4) complex in monocytes, macrophages and dendritic cells of the intestinal mucosa. Non-gluten containing cereals or staples display no or little TLR4 stimulating activity. Wheat ATIs are a family of up to 17 similar proteins of molecular weights around 15kD and represent 2-4% of the wheat protein. With oral ingestion they costimulate antigen presenting cells and promote T cell activation in celiac disease, but also in other immune-mediated diseases within and outside the GI tract. PMID:26060111

  19. WheatGenome.info: A Resource for Wheat Genomics Resource.

    PubMed

    Lai, Kaitao

    2016-01-01

    An integrated database with a variety of Web-based systems named WheatGenome.info hosting wheat genome and genomic data has been developed to support wheat research and crop improvement. The resource includes multiple Web-based applications, which are implemented as a variety of Web-based systems. These include a GBrowse2-based wheat genome viewer with BLAST search portal, TAGdb for searching wheat second generation genome sequence data, wheat autoSNPdb, links to wheat genetic maps using CMap and CMap3D, and a wheat genome Wiki to allow interaction between diverse wheat genome sequencing activities. This portal provides links to a variety of wheat genome resources hosted at other research organizations. This integrated database aims to accelerate wheat genome research and is freely accessible via the web interface at http://www.wheatgenome.info/ . PMID:26519407

  20. Wheat alleles introgress into selfing wild relatives: empirical estimates from approximate Bayesian computation in Aegilops triuncialis.

    PubMed

    Pajkovic, Mila; Lappe, Sylvain; Barman, Rachel; Parisod, Christian; Neuenschwander, Samuel; Goudet, Jerome; Alvarez, Nadir; Guadagnuolo, Roberto; Felber, Franois; Arrigo, Nils

    2014-10-01

    Extensive gene flow between wheat (Triticum sp.) and several wild relatives of the genus Aegilops has recently been detected despite notoriously high levels of selfing in these species. Here, we assess and model the spread of wheat alleles into natural populations of the barbed goatgrass (Aegilops triuncialis), a wild wheat relative prevailing in the Mediterranean flora. Our sampling, based on an extensive survey of 31 Ae. triuncialis populations collected along a 60 km 20 km area in southern Spain (Grazalema Mountain chain, Andalousia, totalling 458 specimens), is completed with 33 wheat cultivars representative of the European domesticated pool. All specimens were genotyped with amplified fragment length polymorphism with the aim of estimating wheat admixture levels in Ae. triuncialis populations. This survey first confirmed extensive hybridization and backcrossing of wheat into the wild species. We then used explicit modelling of populations and approximate Bayesian computation to estimate the selfing rate of Ae. triuncialis along with the magnitude, the tempo and the geographical distance over which wheat alleles introgress into Ae. triuncialis populations. These simulations confirmed that extensive introgression of wheat alleles (2.7 10(-4) wheat immigrants for each Ae. triuncialis resident, at each generation) into Ae. triuncialis occurs despite a high selfing rate (Fis ? 1 and selfing rate = 97%). These results are discussed in the light of risks associated with the release of genetically modified wheat cultivars in Mediterranean agrosystems. PMID:25223217

  1. A large-scale introgression of genomic components of Brassica rapa into B. napus by the bridge of hexaploid derived from hybridization between B. napus and B. oleracea.

    PubMed

    Li, Qinfei; Mei, Jiaqin; Zhang, Yongjing; Li, Jiana; Ge, Xianhong; Li, Zaiyun; Qian, Wei

    2013-08-01

    Brassica rapa (AA) has been used to widen the genetic basis of B. napus (AACC), which is a new but important oilseed crop worldwide. In the present study, we have proposed a strategy to develop new type B. napus carrying genomic components of B. rapa by crossing B. rapa with hexaploid (AACCCC) derived from B. napus and B. oleracea (CC). The hexaploid exhibited large flowers and high frequency of normal chromosome segregation, resulting in good seed set (average of 4.48 and 12.53 seeds per pod by self and open pollination, respectively) and high pollen fertility (average of 87.05%). It was easy to develop new type B. napus by crossing the hexaploid with 142 lines of B. rapa from three ecotype groups, with the average crossability of 9.24 seeds per pod. The genetic variation of new type B. napus was diverse from that of current B. napus, especially in the A subgenome, revealed by genome-specific simple sequence repeat markers. Our data suggest that the strategy proposed here is a large-scale and highly efficient method to introgress genomic components of B. rapa into B. napus. PMID:23699961

  2. Sina and Sinb genes in triticale do not determine grain hardness contrary to their orthologs Pina and Pinb in wheat

    PubMed Central

    2013-01-01

    Background Secaloindoline a (Sina) and secaloindoline b (Sinb) genes of hexaploid triticale (x Triticosecale Wittmack) are orthologs of puroindoline a (Pina) and puroindoline b (Pinb) in hexaploid wheat (Triticum aestivum L.). It has already been proven that RNA interference (RNAi)-based silencing of Pina and Pinb genes significantly decreased the puroindoline a and puroindoline b proteins in wheat and essentially increased grain hardness (J Exp Bot 62:4025-4036, 2011). The function of Sina and Sinb in triticale was tested by means of RNAi silencing and compared to wheat. Results Novel Sina and Sinb alleles in wild-type plants of cv. Wanad were identified and their expression profiles characterized. Alignment with wheat Pina-D1a and Pinb-D1a alleles showed 95% and 93.3% homology with Sina and Sinb coding sequences. Twenty transgenic lines transformed with two hpRNA silencing cassettes directed to silence Sina or Sinb were obtained by the Agrobacterium-mediated method. A significant decrease of expression of both Sin genes in segregating progeny of tested T1 lines was observed independent of the silencing cassette used. The silencing was transmitted to the T4 kernel generation. The relative transcript level was reduced by up to 99% in T3 progeny with the mean for the sublines being around 90%. Silencing of the Sin genes resulted in a substantial decrease of secaloindoline a and secaloindoline b content. The identity of SIN peptides was confirmed by mass spectrometry. The hardness index, measured by the SKCS (Single Kernel Characterization System) method, ranged from 22 to 56 in silent lines and from 37 to 49 in the control, and the mean values were insignificantly lower in the silent ones, proving increased softness. Additionally, the mean total seed protein content of silenced lines was about 6% lower compared with control lines. Correlation coefficients between hardness and transcript level were weakly positive. Conclusions We documented that RNAi-based silencing of Sin genes resulted in significant decrease of their transcripts and the level of both secaloindoline proteins, however did not affect grain hardness. The unexpected, functional differences of Sin genes from triticale compared with their orthologs, Pin of wheat, are discussed. PMID:24279512

  3. Wheat Quality Council Hard Spring Wheat Technical Committee 2010 Crop

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Breeders experimental lines of wheat are evaluated for overall quality before being released for commercial production. The Hard Spring Wheat Technical Committee provides milling and baking quality data on breeders experimental lines of wheat that are annually submitted to the Wheat Quality Counc...

  4. Quantitative trait loci and epistasis for crown freezing tolerance in the Kanota x Ogle hexaploid oat mapping population.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Winter hardiness is a complex trait, and poor winter hardiness limits commercial production of winter oat. Crown freeze tolerance is the most important factor conferring winter hardiness, and controlled crown freeze tests correlate well with field winter hardiness. The objective of this study was ...

  5. Effects of herbicide applications in wheat fields

    PubMed Central

    Varshney, Sugandha; Hayat, Shamshul; Alyemeni, Mohammed Nasser; Ahmad, Aqil

    2012-01-01

    The present review encompasses the physiological and yield constraints of herbicide applications with special reference to wheat productivity. Post-independence lagging of Indian agriculture to feed its population led to haphazard use of chemical pesticides and weedicides which deteriorated the productivity pay-off particularly of wheat and rice. Past some decades witnessed the potential use of certain phytohormones in augmenting abiotic stress to get rid of yield gap and productivity constraints. We summed up with reviewing the potential role of these natural regulators in overcoming above mentioned drawbacks to substitute or to integrate these chemicals with the use of plant hormones. PMID:22516826

  6. Fine-Mapping the Wheat Snn1 Locus Conferring Sensitivity to the Parastagonospora nodorum Necrotrophic Effector SnTox1 Using an Eight Founder Multiparent Advanced Generation Inter-Cross Population.

    PubMed

    Cockram, James; Scuderi, Alice; Barber, Toby; Furuki, Eiko; Gardner, Keith A; Gosman, Nick; Kowalczyk, Radoslaw; Phan, Huyen P; Rose, Gemma A; Tan, Kar-Chun; Oliver, Richard P; Mackay, Ian J

    2015-01-01

    The necrotrophic fungus Parastagonospora nodorum is an important pathogen of one of the world's most economically important cereal crops, wheat (Triticum aestivum L.). P. nodorum produces necrotrophic protein effectors that mediate host cell death, providing nutrients for continuation of the infection process. The recent discovery of pathogen effectors has revolutionized disease resistance breeding for necrotrophic diseases in crop species, allowing often complex genetic resistance mechanisms to be broken down into constituent parts. To date, three effectors have been identified in P. nodorum. Here we use the effector, SnTox1, to screen 642 progeny from an eight-parent multiparent advanced generation inter-cross (i.e., MAGIC) population, genotyped with a 90,000-feature single-nucleotide polymorphism array. The MAGIC founders showed a range of sensitivity to SnTox1, with transgressive segregation evident in the progeny. SnTox1 sensitivity showed high heritability, with quantitative trait locus analyses fine-mapping the Snn1 locus to the short arm of chromosome 1B. In addition, a previously undescribed SnTox1 sensitivity locus was identified on the long arm of chromosome 5A, termed here QSnn.niab-5A.1. The peak single-nucleotide polymorphism for the Snn1 locus was converted to the KASP genotyping platform, providing breeders and researchers a simple and cheap diagnostic marker for allelic state at Snn1. PMID:26416667

  7. Fine-Mapping the Wheat Snn1 Locus Conferring Sensitivity to the Parastagonospora nodorum Necrotrophic Effector SnTox1 Using an Eight Founder Multiparent Advanced Generation Inter-Cross Population

    PubMed Central

    Cockram, James; Scuderi, Alice; Barber, Toby; Furuki, Eiko; Gardner, Keith A.; Gosman, Nick; Kowalczyk, Radoslaw; Phan, Huyen P.; Rose, Gemma A.; Tan, Kar-Chun; Oliver, Richard P.; Mackay, Ian J.

    2015-01-01

    The necrotrophic fungus Parastagonospora nodorum is an important pathogen of one of the world’s most economically important cereal crops, wheat (Triticum aestivum L.). P. nodorum produces necrotrophic protein effectors that mediate host cell death, providing nutrients for continuation of the infection process. The recent discovery of pathogen effectors has revolutionized disease resistance breeding for necrotrophic diseases in crop species, allowing often complex genetic resistance mechanisms to be broken down into constituent parts. To date, three effectors have been identified in P. nodorum. Here we use the effector, SnTox1, to screen 642 progeny from an eight-parent multiparent advanced generation inter-cross (i.e., MAGIC) population, genotyped with a 90,000-feature single-nucleotide polymorphism array. The MAGIC founders showed a range of sensitivity to SnTox1, with transgressive segregation evident in the progeny. SnTox1 sensitivity showed high heritability, with quantitative trait locus analyses fine-mapping the Snn1 locus to the short arm of chromosome 1B. In addition, a previously undescribed SnTox1 sensitivity locus was identified on the long arm of chromosome 5A, termed here QSnn.niab-5A.1. The peak single-nucleotide polymorphism for the Snn1 locus was converted to the KASP genotyping platform, providing breeders and researchers a simple and cheap diagnostic marker for allelic state at Snn1. PMID:26416667

  8. Influence of Commodity Type, Percentage of Cracked Kernels, and Wheat Class on Population Growth of Stored-Product Psocids (Psocoptera: Liposcelidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of the type of grain commodity on population growth of four psocid species, Liposcelis bostrychophila Badonnel, L. decolor (Pearman), L. paeta Pearman, and L. entomophila (Enderlein) (Psocoptera: Liposcelididae), was examined under laboratory conditions. Sorghum was the most suitable for ...

  9. Effects of combined thiamethoxam and diatomaceous earth on mortality and progeny production of four Pakistani populations of Rhyzopertha dominica (Coleoptera: Bostrychidae) on wheat, rice and maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bioassays were conducted to evaluate the effects of combining thiamethoxam at 0.25, 0.5 and 0.75 mg/kg with the diatomaceous earth (DE) formulation, SilicoSec, at the rate of 100 mg/kg against four diverse populations of the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae) th...

  10. Registration of 'Ripper' Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Ripper’ (Reg. No. CV-1016, PI 644222) hard red winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released in August 2006 through an exclusive marketing agreement with the Colorado Wheat Research Foundation. In addition to researchers at Colorado S...

  11. Registration of "Select" Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium head blight (FHB), caused by Fusarium graminearum, Schwabe [telomorph Gibberella zeae (Schwein.) Petch]), is a major constraint on the production of spring wheat (Triticum aestivum L.). The objective of this research was to release a hard red spring wheat (HRSW) cultivar with enhanced level...

  12. Registration of 'Byrd' wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'Byrd' (PI 664257) hard red winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released August, 2011, through a marketing agreement with the Colorado Wheat Research Foundation. In addition to researchers at Colorado State University (CSU), USDA-ARS ...

  13. Registration of 'Denali' wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'Denali' (PI 664256) hard red winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released cooperatively by Colorado State University (CSU) and Kansas State University (KSU) August, 2011, through a marketing agreement with the Colorado Wheat Research...

  14. Registration of Whit wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stripe rust (Puccinia striiformis Westend f. sp. tritici) resistance is an essential trait for spring wheat cultivars produced in the Pacific Northwest region of the United States. The objective of this research was to develop an adapted spring wheat cultivar with high levels of resistance to stripe...

  15. Registration of 'Okfield' wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'Okfield' (Reg. No. CV-_______, PI 643087) is a hard red winter (HRW) wheat (Triticum aestivum L.) cultivar developed and released cooperatively by the Oklahoma Agric. Exp. Stn. (AES) and the USDA-ARS in 2005. It is recommended for dryland wheat production using either grain-only and dual-purpose m...

  16. Wheat: Science and Trade

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Up-to-date textbooks are needed to educate the agricultural scientists of tomorrow. This manuscript comprises one chapter in such a textbook, “Wheat: Science and Trade”, and covers the subject of wheat genetic engineering. The chapter begins with a summary of key discussion elements and ends with a...

  17. Registration of Yellowstone wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'Yellowstone' hard red winter wheat (Triticum aestivum L.) was developed by the Montana Agricultural Experiment Station and released in September 2005. Yellowstone was released for its high yield potential and broad adaptation to Montana winter wheat production environments. Yellowstone was named in...

  18. Registration of 'Antero' Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ’Antero’ (Reg. No. CV-XXXX, PI 667743) hard white winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released in August 2012 through a marketing agreement with the Colorado Wheat Research Foundation. In addition to researchers at Colorado State Univ...

  19. Registration of "Brick" Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium head blight (FHB) [caused by Fusarium graminearum Schwabe; telomorph Gibberella zeae (Schwein.) Petch, is a major constraint to spring wheat (Triticum aestivum L.) production. The objective of this research was to release a hard red spring wheat (HRSW) cultivar with enhanced FHB resistance....

  20. Agrometeorology and Wheat Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Winter wheat phenology varies among shoots on the plant to main stems on plants within a plot to locations across a landscape. Most often phenological measurements have focused on small treatment plots under presumably similar soils and topography. Many models exist to predict wheat phenology for sm...

  1. Registration of Ripper Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ripper (Reg. No. CV-1016, PI 644222) hard red winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released in August 2006 through an exclusive marketing agreement with the Colorado Wheat Research Foundation. In addition to researchers at Colorado S...

  2. Registration of 'Snowmass' wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Snowmass (Reg. No. CV-1050, PI 658597) hard white winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released in July 2009 through a marketing agreement with the Colorado Wheat Research Foundation. In addition to researchers at Colorado State Uni...

  3. Isolation and characterization of microsatellite loci in wheat stem sawfly Cephus cinctus and cross-species amplification in related species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The wheat stem sawfly is an important insect pest of wheat that can cause significant damage to yield and grain quality. Five microsatellite loci were isolated and characterized in wheat stem sawfly, Cephus cinctus, to facilitate future population genetic studies and help delineate their geographica...

  4. Dissemination of the highly expressed Bx7 glutenin subunit (Glu-B1al allele) in wheat as revealed by novel PCR markers and RP-HPLC.

    PubMed

    Butow, B J; Gale, K R; Ikea, J; Juhsz, A; Bed, Z; Tams, L; Gianibelli, M C

    2004-11-01

    Increased expression of the high molecular weight glutenin subunit (HMW-GS) Bx7 is associated with improved dough strength of wheat (Triticum aestivum L.) flour. Several cultivars and landraces of widely different genetic backgrounds from around the world have now been found to contain this so-called 'over-expressing' allelic form of the Bx7 subunit encoded by Glu-B1al. Using three methods of identification, SDS-PAGE, RP-HPLC and PCR marker analysis, as well as pedigree information, we have traced the distribution and source of this allele from a Uruguayan landrace, Americano 44D, in the mid-nineteenth century. Results are supported by knowledge of the movement of wheat lines with migrants. All cultivars possessing the Glu-B1al allele can be identified by the following attributes: (1) the elution of the By sub-unit peak before the Dx sub-unit peak by RP-HPLC, (2) high expression levels of Bx7 (>39% Mol% Bx), (3) a 43 bp insertion in the matrix-attachment region (MAR) upstream of the gene promoter relative to Bx7 and an 18 bp nucleotide duplication in the coding region of the gene. Evidence is presented indicating that these 18 and 43 bp sequence insertions are not causal for the high expression levels of Bx7 as they were also found to be present in a small number of hexaploid species, including Chinese Spring, and species expressing Glu-B1ak and Glu-B1a alleles. In addition, these sequence inserts were found in different isolates of the tetraploid wheat, T. turgidum, indicating that these insertion/deletion events occurred prior to hexaploidization. PMID:15340686

  5. Isolation and characterization of a gene encoding a polyethylene glycol-induced cysteine protease in common wheat.

    PubMed

    Zang, Qing-Wei; Wang, Cai-Xiang; Li, Xu-Yan; Guo, Zhi-Ai; Jing, Rui-Lian; Zhao, Jun; Chang, Xiao-Ping

    2010-09-01

    Plant cysteine protease (CP) genes are induced by abiotic stresses such as drought, yet their functions remain largely unknown. We isolated the full-length cDNA encoding a Triticum aestivum CP gene, designated TaCP, from wheat by the rapid amplification of cDNA ends (RACE) method. Sequence analysis revealed that TaCP contains an open reading frame encoding a protein of 362 amino acids, which is 96% identical to barley cysteine protease HvSF42. The TaCP transcript level in wheat seedlings was upregulated during polyethylene glycol (PEG) stress, with a peak appearing around 12 h after treatment. TaCP expression level increased rapidly with NaCl treatment at 48 h. TaCP responded strongly to low temperature (4 degree C) treatment from 1 h post-treatment and reached a peak of about 40-fold at 72 h. However, it showed only a very slight response to abscisic acid (ABA). More than one copy of TaCP was present in each of the three genomes of hexaploid wheat and its diploid donors. TaCP fused with green fluorescent protein (GFP) was located in the plasma membrane of onion epidermis cells. Transgenic Arabidopsis plants overexpressing TaCP showed stronger drought tolerance and higher CP activity under water-stressed conditions than wild-type Arabidopsis plants. The results suggest that TaCP plays a role in tolerance to water deficit. PMID:20826947

  6. Sequence-Based Mapping of the Polyploid Wheat Genome

    PubMed Central

    Saintenac, Cyrille; Jiang, Dayou; Wang, Shichen; Akhunov, Eduard

    2013-01-01

    The emergence of new sequencing technologies has provided fast and cost-efficient strategies for high-resolution mapping of complex genomes. Although these approaches hold great promise to accelerate genome analysis, their application in studying genetic variation in wheat has been hindered by the complexity of its polyploid genome. Here, we applied the next-generation sequencing of a wheat doubled-haploid mapping population for high-resolution gene mapping and tested its utility for ordering shotgun sequence contigs of a flow-sorted wheat chromosome. A bioinformatical pipeline was developed for reliable variant analysis of sequence data generated for polyploid wheat mapping populations. The results of variant mapping were consistent with the results obtained using the wheat 9000 SNP iSelect assay. A reference map of the wheat genome integrating 2740 gene-associated single-nucleotide polymorphisms from the wheat iSelect assay, 1351 diversity array technology, 118 simple sequence repeat/sequence-tagged sites, and 416,856 genotyping-by-sequencing markers was developed. By analyzing the sequenced megabase-size regions of the wheat genome we showed that mapped markers are located within 40−100 kb from genes providing a possibility for high-resolution mapping at the level of a single gene. In our population, gene loci controlling a seed color phenotype cosegregated with 2459 markers including one that was located within the red seed color gene. We demonstrate that the high-density reference map presented here is a useful resource for gene mapping and linking physical and genetic maps of the wheat genome. PMID:23665877

  7. Metabolite Profiling of a Diverse Collection of Wheat Lines Using Ultraperformance Liquid Chromatography Coupled with Time-of-Flight Mass Spectrometry

    PubMed Central

    Wolfe, Pamela; Byrne, Patrick F.; Thompson, Henry J.

    2012-01-01

    Genetic differences among major types of wheat are well characterized; however, little is known about how these distinctions affect the small molecule profile of the wheat seed. Ethanol/water (65% v/v) extracts of seed from 45 wheat lines representing 3 genetically distinct classes, tetraploid durum (Triticum turgidum subspecies durum) (DW) and hexaploid hard and soft bread wheat (T. aestivum subspecies aestivum) (BW) were subjected to ultraperformance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC-TOF-MS). Discriminant analyses distinguished DW from BW with 100% accuracy due to differences in expression of nonpolar and polar ions, with differences attributed to sterol lipids/fatty acids and phospholipids/glycerolipids, respectively. Hard versus soft BW was distinguished with 100% accuracy by polar ions, with differences attributed to heterocyclic amines and polyketides versus phospholipid ions, respectively. This work provides a foundation for identification of metabolite profiles associated with desirable agronomic and human health traits and for assessing how environmental factors impact these characteristics. PMID:22957002

  8. Construction and evaluation of cDNA libraries for large-scale expressed sequence tag sequencing in wheat (Triticum aestivum L.).

    PubMed

    Zhang, D; Choi, D W; Wanamaker, S; Fenton, R D; Chin, A; Malatrasi, M; Turuspekov, Y; Walia, H; Akhunov, E D; Kianian, P; Otto, C; Simons, K; Deal, K R; Echenique, V; Stamova, B; Ross, K; Butler, G E; Strader, L; Verhey, S D; Johnson, R; Altenbach, S; Kothari, K; Tanaka, C; Shah, M M; Laudencia-Chingcuanco, D; Han, P; Miller, R E; Crossman, C C; Chao, S; Lazo, G R; Klueva, N; Gustafson, J P; Kianian, S F; Dubcovsky, J; Walker-Simmons, M K; Gill, K S; Dvork, J; Anderson, O D; Sorrells, M E; McGuire, P E; Qualset, C O; Nguyen, H T; Close, T J

    2004-10-01

    A total of 37 original cDNA libraries and 9 derivative libraries enriched for rare sequences were produced from Chinese Spring wheat (Triticum aestivum L.), five other hexaploid wheat genotypes (Cheyenne, Brevor, TAM W101, BH1146, Butte 86), tetraploid durum wheat (T. turgidum L.), diploid wheat (T. monococcum L.), and two other diploid members of the grass tribe Triticeae (Aegilops speltoides Tausch and Secale cereale L.). The emphasis in the choice of plant materials for library construction was reproductive development subjected to environmental factors that ultimately affect grain quality and yield, but roots and other tissues were also included. Partial cDNA expressed sequence tags (ESTs) were examined by various measures to assess the quality of these libraries. All ESTs were processed to remove cloning system sequences and contaminants and then assembled using CAP3. Following these processing steps, this assembly yielded 101,107 sequences derived from 89,043 clones, which defined 16,740 contigs and 33,213 singletons, a total of 49,953 "unigenes." Analysis of the distribution of these unigenes among the libraries led to the conclusion that the enrichment methods were effective in reducing the most abundant unigenes and to the observation that the most diverse libraries were from tissues exposed to environmental stresses including heat, drought, salinity, or low temperature. PMID:15514038

  9. Argentina wheat yield model

    NASA Technical Reports Server (NTRS)

    Callis, S. L.; Sakamoto, C.

    1984-01-01

    Five models based on multiple regression were developed to estimate wheat yields for the five wheat growing provinces of Argentina. Meteorological data sets were obtained for each province by averaging data for stations within each province. Predictor variables for the models were derived from monthly total precipitation, average monthly mean temperature, and average monthly maximum temperature. Buenos Aires was the only province for which a trend variable was included because of increasing trend in yield due to technology from 1950 to 1963.

  10. Molecular characterization and genomic mapping of the pathogenesis-related protein 1 (PR-1) gene family in hexaploid wheat (Triticum aestivum L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The group 1 pathogenesis-related (PR-1) proteins, known as hallmarks of defense pathways, are encoded by multigene families in plants as evidenced by the presence of 22 and 32 PR-1 genes in the finished Arabidopsis and rice genomes, respectively. Here, we report the initial characterization and mapp...

  11. A high-density, SNP-based consensus map of tetraploid wheat as a bridge to integrate durum and bread wheat genomics and breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Consensus linkage maps are important tools in crop genomics. We have assembled a high-density tetraploid wheat consensus map by integrating 13 datasets from independent biparental populations involving durum wheat cultivars (Triticum turgidum ssp. durum), cultivated emmer (T. turgidum ssp. dicoccum...

  12. Wheat for Kids! [and] Teacher's Guide.

    ERIC Educational Resources Information Center

    Idaho Wheat Commission, Boise.

    "Wheat for Kids" contains information at the elementary school level about: the structure of the wheat kernel; varieties of wheat and their uses; growing wheat; making wheat dough; the U.S. Department of Agriculture Food Guide Pyramid and nutrition; Idaho's part of the international wheat market; recipes; and word games based on the information…

  13. 21 CFR 184.1322 - Wheat gluten.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Wheat gluten. 184.1322 Section 184.1322 Food and....1322 Wheat gluten. (a) Wheat gluten (CAS Reg. No. 8002-80-0) is the principal protein component of wheat and consists mainly of gliadin and glutenin. Wheat gluten is obtained by hydrating wheat flour...

  14. Wheat for Kids! [and] Teacher's Guide.

    ERIC Educational Resources Information Center

    Idaho Wheat Commission, Boise.

    "Wheat for Kids" contains information at the elementary school level about: the structure of the wheat kernel; varieties of wheat and their uses; growing wheat; making wheat dough; the U.S. Department of Agriculture Food Guide Pyramid and nutrition; Idaho's part of the international wheat market; recipes; and word games based on the information

  15. WHEAT QUALITY COUNCIL HARD SPRING WHEAT 2001 CROP REPORT.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Hard Spring Wheat Technical Committee provides quality data relating the milling and baking properties of experimental lines of wheat that were grown and tested in the 2001 crop. The data in this report were developed under code and provided to the Wheat Quality Council (WQC) by the USDA Hard R...

  16. Wheat Quality Council, Hard Spring Wheat Technical Committee, 2014 Crop

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eleven experimental lines of hard spring wheat were grown at up to five locations in 2014 and evaluated for kernel, milling, and bread baking quality against the check variety Glenn. Wheat samples were submitted through the Wheat Quality Council and processed and milled at the USDA-ARS Hard Red Spr...

  17. New Uses for Wheat and Modified Wheat Products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hard wheat from the Great Plains historically has been used as a source of flour for the production of leavened bakery products. However, potentially applications of wheat in both new markets and new products has necessitated the need to develop wheats with novel processing attributes. The most lo...

  18. Insects which challenge global wheat production: Russian wheat aphid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The book chapter on Russian wheat aphid, (Diuraphis noxia (Mord.)), is one of several that addresses significant pests in the book entitled, Wheat Science and Trade. The chapter gives a detailed account of the history of the Russian wheat aphid as global pest, and its biology, ecology and managemen...

  19. Short, natural, and extended photoperiod response in BC2F4 lines of bread wheat with different photoperiod-1 (Ppd-1) alleles.

    PubMed

    Bentley, A R; Horsnell, R; Werner, C P; Turner, A S; Rose, G A; Bedard, C; Howell, P; Wilhelm, E P; Mackay, I J; Howells, R M; Greenland, A; Laurie, D A; Gosman, N

    2013-04-01

    Flowering is a critical period in the life cycle of flowering plant species, resulting in an irreversible commitment of significant resources. Wheat is photoperiod sensitive, flowering only when daylength surpasses a critical length; however, photoperiod insensitivity (PI) has been selected by plant breeders for >40 years to enhance yield in certain environments. Control of flowering time has been greatly facilitated by the development of molecular markers for the Photoperiod-1 (Ppd-1) homeoloci, on the group 2 chromosomes. In the current study, an allelic series of BC2F4 lines in the winter wheat cultivars 'Robigus' and 'Alchemy' was developed to elucidate the influence on flowering of eight gene variants from the B- and D-genomes of bread wheat and the A-genome of durum wheat. Allele effects were tested in short, natural, and extended photoperiods in the field and controlled environments. Across genetic background and treatment, the D-genome PI allele, Ppd-D1a, had a more potent effect on reducing flowering time than Ppd-B1a. However, there was significant donor allele effect for both Ppd-D1a and Ppd-B1a, suggesting the presence of linked modifier genes and/or additional sources of latent sensitivity. Development of Ppd-A1a BC2F4 lines derived from synthetic hexaploid wheat provided an opportunity to compare directly the flowering time effect of the A-genome allele from durum with the B- and D-genome variants from bread wheat for the first time. Analyses indicated that the reducing effect of Ppd-A1a is comparable with that of Ppd-D1a, confirming it as a useful alternative source of PI. PMID:23420880

  20. Flowering time control in European winter wheat

    PubMed Central

    Langer, Simon M.; Longin, C. Friedrich H.; Würschum, Tobias

    2014-01-01

    Flowering time is an important trait in wheat breeding as it affects adaptation and yield potential. The aim of this study was to investigate the genetic architecture of flowering time in European winter bread wheat cultivars. To this end a population of 410 winter wheat varieties was evaluated in multi-location field trials and genotyped by a genotyping-by-sequencing approach and candidate gene markers. Our analyses revealed that the photoperiod regulator Ppd-D1 is the major factor affecting flowering time in this germplasm set, explaining 58% of the genotypic variance. Copy number variation at the Ppd-B1 locus was present but explains only 3.2% and thus a comparably small proportion of genotypic variance. By contrast, the plant height loci Rht-B1 and Rht-D1 had no effect on flowering time. The genome-wide scan identified six QTL which each explain only a small proportion of genotypic variance and in addition we identified a number of epistatic QTL, also with small effects. Taken together, our results show that flowering time in European winter bread wheat cultivars is mainly controlled by Ppd-D1 while the fine tuning to local climatic conditions is achieved through Ppd-B1 copy number variation and a larger number of QTL with small effects. PMID:25346745

  1. Wheat-based foods and non celiac gluten/wheat sensitivity: Is drastic processing the main key issue?

    PubMed

    Fardet, Anthony

    2015-12-01

    While gluten and wheat must be absolutely avoided in coeliac disease and allergy, respectively, nutritional recommendations are largely more confused about non-coeliac wheat/gluten sensitivity (NCWGS). Today, some even recommend avoiding all cereal-based foods. In this paper, the increased NCWGS prevalence is hypothesized to parallel the use of more and more drastic processes applied to the original wheat grain. First, a parallel between gluten-related disorders and wheat processing and consumption evolution is briefly proposed. Notably, increased use of exogenous vital gluten is considered. Drastic processing in wheat technology are mainly grain fractionation and refining followed by recombination and salt, sugars and fats addition, being able to render ultra-processed cereal-based foods more prone to trigger chronic low-grade inflammation. Concerning bread, intensive kneading and the choice of wheat varieties with high baking quality may have rendered gluten less digestible, moving digestion from pancreatic to intestinal proteases. The hypothesis of a gluten resistant fraction reaching colon and interacting with microflora is also considered in relation with increased inflammation. Besides, wheat flour refining removes fiber co-passenger which have potential anti-inflammatory property able to protect digestive epithelium. Finally, some research tracks are proposed, notably the comparison of NCWGS prevalence in populations consuming ultra-versus minimally-processed cereal-based foods. PMID:26364045

  2. Uniquely identifying wheat plant structures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Uniquely naming wheat (Triticum aestivum L. em Thell) plant parts is useful for communicating plant development research and the effects of environmental stresses on normal wheat development. Over the past 30+ years, several naming systems have been proposed for wheat shoot, leaf, spike, spikelet, ...

  3. Directional Flow of Summer Aeration to Manage Insect Pests in Stored Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field trials were conducted in metal wheat storage bins to determine whether pressure aeration, pushing ambient air from the bottom, or suction aeration, pulling air down from the top, would be more efficient at cooling the wheat mass and thereby limiting insect population growth. Aeration was accom...

  4. Resistance to Ug99 stem rust in six bread wheat cultivars maps to chromosome 6DS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over 80% of wheat area worldwide is currently grown to varieties that are susceptible to the Ug99 race group of the stem rust fungus. Wheat lines Niini, Tinkio, Coni, Pfunye, Blouk and Ripper were resistant to Ug99 at the seedling and adult plant stages. We mapped stem rust resistance in populations...

  5. Biolistics Transformation of Wheat

    NASA Astrophysics Data System (ADS)

    Sparks, Caroline A.; Jones, Huw D.

    We present a complete, step-by-step guide to the production of transformed wheat plants using a particle bombardment device to deliver plasmid DNA into immature embryos and the regeneration of transgenic plants via somatic embryogenesis. Currently, this is the most commonly used method for transforming wheat and it offers some advantages. However, it will be interesting to see whether this position is challenged as facile methods are developed for delivering DNA by Agrobacterium tumefaciens or by the production of transformants via a germ-line process (see other chapters in this book).

  6. [The effectiveness of molecular markers for the identification of Lr28, Lr35, and Lr47 genes in common wheat].

    PubMed

    Gul'tiaeva, E I; Orina, A S; Gannibal, F B; Mitrofanova, O P; Odintsova, I G; Laĭkova, L I

    2014-02-01

    The effectiveness of molecular markers for the identification of leaf rust resistance genes Lr28, Lr35, Lr47 transferred to common wheat was assessed the using samplesof Triticum spp. and Aegilops spp. from Ae. speltoides. Markers Sr39F2/R3, BCD260F1/35R2 of gene Lr35 and PS10 of Lr47 gene were characterized by high efficiency and were revealed in a line of common wheat containing these genes, and samples of Ae. speltoides (their donor). Marker SCS421 of Lr28gene and markers Sr39#22r, Sr39#50s, BE500705 of Lr35/Sr39 genes turned out to be less specific. Marker SCS421 was amplified in the samples of the T. timopheevii species, and markers Sr39#22r, Sr39#50s--in the Ae. speltoides, Ae. tauschii, T. timopheevii, line KS90WRC010 (Lr41), the sort of common wheat In Memory of Maistrenko, obtained using synthetic hexaploid T. timopheevii x Ae. tauschii and introgressive lines obtained using Ae. speltoides. Marker BE500705, which indicates the absence of Lr35/Sr39 genes, was not revealed in lines TcLr35 and MqSr39, in Ae. speltoides, Ae. tauschii and T. boeoticum (kk-61034, 61038). Analysis of the nucleotide sequences of amplification products obtained with the markers SCS421 and Sr39#22r indicated their low homology with TcLr28 and TcLr35. Using molecular markers, we showed a different distribution of Lr28 (77%), Lr35 (100%) and Lr47 (15%) genes in 13 studied samples ofAe. speltoides. In introgressive lines derived from Ae. speltoides, contemporary Russian sorts of common wheat and triticale variants Lr28, Lr35, Lr47 genes were not revealed. PMID:25711022

  7. [Analysis of storage proteins (prolamines, puroindolines and waxy) in common wheat lines Triticum aestivum L. x (Triticum timopheevii Zhuk. x Triticum tauschii) with complex resistance to fungal infections].

    PubMed

    Obukhova, L V; La?kova, L I; Shumny?, V K

    2010-06-01

    Storage proteins (prolamines, puroindolines, and Waxy) were studied in common wheat introgression lines obtained with the use of the Saratovskaya 29 (S29) cultivar line and synthetic hexaploid wheat (Triticum timopheevii Zhuk. x T. tauschii) (Sintetik, Sin.) and displaying complex resistance to fungal infections. Comparative analysis of storage proteins in the introgression lines of common wheat Triticum aestivum L. and in the parental forms revealed the only line (BC5) having a substitution at the Gli-B2 locus from Sintetik. Hybrid lines subjected to nine back crosses with the recurrent parental form S29 and selections for resistance to pathogens can be considered as nearly isogenic for the selected trait and retaining the allelic composition of (1) prolamines responsible for the bread-making qualitiy, (2) puroindolines associated with grain texture, and (3) Waxy proteins responsible for nutritive qualities. These lines are valuable as donors of immunity in breeding programs without the loss of the quality of flour and grain as compared to the S29 line and are also important in searching for genes determining resistance to leaf and stem rust and to powdery mildew. The amphiploid has a number of characters (silent Glu-A 1 locus and Ha genotype) that can negatively affect the quality of flour and grain and thus should be taken into account when choosing this donor. PMID:20734767

  8. Accumulation of an acidic dehydrin in the vicinity of the plasma membrane during cold acclimation of wheat

    PubMed Central

    Danyluk, J; Perron, A; Houde, M; Limin, A; Fowler, B; Benhamou, N; Sarhan, F

    1998-01-01

    Expression of the acidic dehydrin gene wcor410 was found to be associated with the development of freezing tolerance in several Gramineae species. This gene is part of a family of three homologous members, wcor410, wcor410b, and wcor410c, that have been mapped to the long arms of the homologous group 6 chromosomes of hexaploid wheat. To gain insight into the function of this gene family, antibodies were raised against the WCOR410 protein and affinity purified to eliminate cross-reactivity with the WCS120 dehydrin-like protein of wheat. Protein gel blot analyses showed that the accumulation of WCOR410 proteins correlates well with the capacity of each cultivar to cold acclimate and develop freezing tolerance. Immunoelectron microscope analyses revealed that these proteins accumulate in the vicinity of the plasma membrane of cells in the sensitive vascular transition area where freeze-induced dehydration is likely to be more severe. Biochemical fractionation experiments indicated that WCOR410 is a peripheral protein and not an integral membrane protein. These results provide direct evidence that a subtype of the dehydrin family accumulates near the plasma membrane. The properties, abundance, and localization of these proteins suggest that they are involved in the cryoprotection of the plasma membrane against freezing or dehydration stress. We propose that WCOR410 plays a role in preventing the destabilization of the plasma membrane that occurs during dehydrative conditions. PMID:9548987

  9. Genetic characterization and molecular mapping of Hessian fly resistance genes derived from Aegilops tauschii in synthetic wheat.

    PubMed

    Wang, Tao; Xu, Steven S; Harris, Marion O; Hu, Jinguo; Liu, Liwang; Cai, Xiwen

    2006-08-01

    Two synthetic hexaploid wheat lines (xAegilotriticum spp., 2n = 6x = 42, genomes AABBDD), SW8 and SW34, developed from the crosses of the durum wheat cultivar Langdon (Triticum turgidum L. var. durum, 2n = 4x = 28, genomes AABB) with two Aegilops tauschii Cosson accessions (2n = 2x = 14, genome DD), were determined to carry Hessian fly [Mayetiola destructor (Say)] resistance genes derived from the Ae. tauschii parents. SW8 was resistant to the Hessian fly biotype Great Plains (GP) and strain vH13 (virulent to H13). SW34 was resistant to biotype GP, but susceptible to strain vH13. Allelism tests indicated that resistance genes in SW8 and SW34 may be allelic to H26 and H13 or correspond to paralogs at both loci, respectively. H26 and H13 were localized to chromosome 4D and 6D, respectively, in previous studies. Molecular mapping in the present study, however, assigned the H26 locus to chromosome 3D rather than 4D. On the other hand, mapping of the resistance gene in SW34 verified the previous assignment of the H13 locus to chromosome 6D. Linkage analysis and physical mapping positioned the H26 locus to the chromosomal deletion bin 3DL3-0.81-1.00. A linkage map for each of these two resistance genes was constructed using simple sequence repeat (SSR) and target region amplification polymorphism (TRAP) markers. PMID:16775694

  10. 21 CFR 137.190 - Cracked wheat.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Cracked wheat. 137.190 Section 137.190 Food and... Related Products § 137.190 Cracked wheat. Cracked wheat is the food prepared by so cracking or cutting... such wheat, other than moisture, remain unaltered. Cracked wheat contains not more than 15 percent...

  11. 21 CFR 137.190 - Cracked wheat.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Cracked wheat. 137.190 Section 137.190 Food and... Related Products § 137.190 Cracked wheat. Cracked wheat is the food prepared by so cracking or cutting... such wheat, other than moisture, remain unaltered. Cracked wheat contains not more than 15 percent...

  12. 21 CFR 137.190 - Cracked wheat.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Cracked wheat. 137.190 Section 137.190 Food and... Related Products § 137.190 Cracked wheat. Cracked wheat is the food prepared by so cracking or cutting... such wheat, other than moisture, remain unaltered. Cracked wheat contains not more than 15 percent...

  13. 21 CFR 137.190 - Cracked wheat.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Cracked wheat. 137.190 Section 137.190 Food and... Related Products § 137.190 Cracked wheat. Cracked wheat is the food prepared by so cracking or cutting... such wheat, other than moisture, remain unaltered. Cracked wheat contains not more than 15 percent...

  14. 21 CFR 137.190 - Cracked wheat.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Cracked wheat. 137.190 Section 137.190 Food and... Related Products § 137.190 Cracked wheat. Cracked wheat is the food prepared by so cracking or cutting... such wheat, other than moisture, remain unaltered. Cracked wheat contains not more than 15 percent...

  15. 21 CFR 184.1322 - Wheat gluten.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Wheat gluten. 184.1322 Section 184.1322 Food and... Substances Affirmed as GRAS § 184.1322 Wheat gluten. (a) Wheat gluten (CAS Reg. No. 8002-80-0) is the principal protein component of wheat and consists mainly of gliadin and glutenin. Wheat gluten is...

  16. 21 CFR 184.1322 - Wheat gluten.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Wheat gluten. 184.1322 Section 184.1322 Food and... Substances Affirmed as GRAS § 184.1322 Wheat gluten. (a) Wheat gluten (CAS Reg. No. 8002-80-0) is the principal protein component of wheat and consists mainly of gliadin and glutenin. Wheat gluten is...

  17. 21 CFR 184.1322 - Wheat gluten.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Wheat gluten. 184.1322 Section 184.1322 Food and... Substances Affirmed as GRAS § 184.1322 Wheat gluten. (a) Wheat gluten (CAS Reg. No. 8002-80-0) is the principal protein component of wheat and consists mainly of gliadin and glutenin. Wheat gluten is...

  18. 21 CFR 184.1322 - Wheat gluten.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Wheat gluten. 184.1322 Section 184.1322 Food and... Substances Affirmed as GRAS § 184.1322 Wheat gluten. (a) Wheat gluten (CAS Reg. No. 8002-80-0) is the principal protein component of wheat and consists mainly of gliadin and glutenin. Wheat gluten is...

  19. Registration of Howard Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Howard (Reg. no. CV-998, PI 642367) is a hard red spring wheat (HRSP) (Triticum aestivum L.) cultivar developed at North Dakota State University (NDSU) and released by the North Dakota Agricultural Experiment Station (NDAES) in January 2006. Howard was released because it combines a good level of...

  20. Registration of 'Tiger' wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Tiger’ hard white winter wheat (Triticum aestivum L.) was developed at Research Center-Hays, Kansas State University and released by Kansas Agricultural Experiment Station in 2010. Tiger was selected from a three-way cross KS98H245/’Trego’//KS98HW518 made in 1999 at Hays, KS. The objective of this ...

  1. REGISTRATION OF 'BAUERMEISTER' WHEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'Bauermeister' (J981107, WA007939) hard red winter wheat (HRW)(Triticum aestivum L.) (Reg. No. CV-XXX, PI 634717) was released in 2005 by the Agricultural Research Center of Washington State University (WSU) in cooperation with the USDA-ARS. Bauermeister is a semidwarf cultivar adapted to the low- ...

  2. Registration of 'Chesapeake' Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Chesapeake’ (Reg. No. CV-1011, PI 643935) is a soft red winter wheat (Triticum aestivum L.) that was jointly developed and released by the Maryland Agricultural Experiment Station, Department of Plant Science and Landscape Architecture, and the Virginia Agricultural Experiment Station in 2005. Ches...

  3. Registration of Xerpha Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many of the current soft white winter (SWW) wheat (Triticum aestivum L.) cultivars produced in Washington are adapted to specific environments. The objective of this research was to develop a high yielding, disease resistant SWW cultivar with competitive yield potential for all Washington winter whe...

  4. Registration of "Merl" Wheat.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Merl’ (Reg. No. CV- , PI 658598) soft red winter (SRW) wheat (Triticum aestivum L.)developed and tested as VA03W-412 by the Virginia Agricultural Experiment Station was released in March 2009. Merl was derived from the three-way cross ‘Roane’ / Pioneer Brand ‘2643’ // ‘38158’ (PI 619052). Merl is a...

  5. REGISTRATION OF 'DELIVER' WHEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Deliver (Reg. No. CV-_______, PI 639232) hard red winter wheat (Triticum aestivum L.) was released to certified seed growers with permission of the Oklahoma Agricultural Experiment Station (AES) and the USDA-ARS in 2004. Deliver, an awnletted cultivar, was named for its unique and competitive abil...

  6. Registration of 'Guymon' wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'Guymon' (Reg. No. CV-_______, PI 643133) is a hard white (HW) winter wheat (Triticum aestivum L.) cultivar developed and released cooperatively by the Oklahoma Agric. Exp. Stn. (AES) and the USDA-ARS in 2005. It is recommended for grain-only and dual-purpose production systems in an area of the so...

  7. REGISTRATION OF LOUISE WHEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Louise soft white spring wheat (Triticum aestivum L.) (Reg. No. CV-987, PI 634865) was developed and jointly released in August 2005 by the Agricultural Research Center of Washington State University in cooperation with the Agricultural Experiment Stations (AESs) of the University of Idaho and Ore...

  8. Wheat - Aegilops introgressions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aegilops is the most closely related genus to Triticum in the tribe Triticeae. Aegilops speltoides Tausch (B genome donor) and Ae. tauschii Coss. (D genome donor) contributed two of the three genomes present in common wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD genomes). The Aegilops genus c...

  9. REGISTRATION OF 'INTRADA' WHEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'Intrada' is a hard white winter wheat (Triticum aestivum L.) developed cooperatively by the Oklahoma Agricultural Experiment Station, Kansas Agricultural Experiment Station, and the USDA-ARS, and released in September, 2000, in cooperation with the USDA-ARS. Intrada was released for its high yield...

  10. Registration of Shirley Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Shirley (Reg. No. CV-1039, PI 656753) soft red winter (SRW) wheat (Triticum aestivum L.), developed and tested as VA03W-409 by the Virginia Agricultural Experiment Station, was released in March 2008. Shirley was derived from the three-way cross VA94-52-25/Coker 9835//VA96-54-234. Shirley is wid...

  11. Registration of Shirley Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Shirley (Reg. No. CV-, PI) soft red winter (SRW) wheat (Triticum aestivum L.) was developed by the Virginia Agricultural Experiment Station and released in March 2008. Shirley was derived from the three-way cross VA94-52-25 / Coker 9835 (PI 548846 PVPO) // VA96-54-234. Shirley is widely adapted ...

  12. Registration of 5205 Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The soft red winter (SRW) wheat (Triticum aestivum L.) cultivar 5205 (Reg. No. CV-, PI) was developed by the Virginia Agricultural Experiment Station and released in March 2008. Cultivar 5205 was derived from the three-way cross Pioneer Brand 2684 (PI 566923 PVPO) / VA93-54-185 // Pocahontas ...

  13. Registration of 3434 Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The soft red winter (SRW) wheat (Triticum aestivum L.) cultivar 3434 (Reg. No. CV-, PI) was developed by the Virginia Agricultural Experiment Station and released in March 2008. Cultivar 3434 was derived from the three-way cross Roane (PI 612958) / Coker 9835 (PI 548846 PVPO) // VA96W-270. Cul...

  14. Registration of Colter wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Colter’ (Reg. No. CV-1099, PI 670156) hard red winter wheat (Triticum aestivum L.) was developed and released by the Montana Agricultural Experiment Stations in September 2013. Colter was derived from the cross MT9982*2/BZ9W96-895. MT9982 is a sib selection of 'Yellowstone', and BZ9W96-895 is an unr...

  15. Registration of Camelot Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'Camelot ' (PI 653832) hard red winter wheat (Triticum aestivum L.) was developed cooperatively by the Nebraska Agricultural Experiment Station and the USDA-ARS and released in 2008. In addition to researchers at the releasing institutions, USDA-ARS researchers at Manhattan, KS, and St. Paul, MN, ...

  16. Modelling Wheat Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In wheat, a shorter pre-anthesis phase is often associated with increased grain protein content (GPC) but decreased grain yield. Cultivar differences in pre-anthesis development are mainly determined by vernalization requirement, photoperiod sensitivity and earliness per se. This research examines w...

  17. Registration of 'Juniper' Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Juniper’ (PI 639951) is a hard red winter wheat (Triticum aestivum L.) developed by the Idaho Agricultural Experimental Station and released in February 2006. Juniper, named for the town of Juniper, Idaho, was released for its superior yield and quality compared with previous full stature hard red...

  18. REGISTRATION OF 'JERRY' WHEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'Jerry' is a hard red winter wheat (Triticum aestivum L.) cultivar developed by the North Dakota Agricultural Experiment Station in cooperation with the USDA-ARS and released in 2001. Jerry was tested as ND9257 and is an F3-derived line from the cross 'Roughrider'/ND7571//'Arapahoe' made in 1987 by...

  19. Registration of 'Otto' Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resistance to strawbreaker foot rot (caused by Oculimacula yallundae Crous & W. Gams and O. acuformis Crous & W. Gams) and to stripe rust (caused by Puccinia striiformis Westend. f. sp. tritici Eriks.) are important traits for winter wheat cultivars produced in the Pacifi Northwest region of the Uni...

  20. Registration of Ambassador Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    "Ambassador" soft white winter wheat (Triticum aestivum L.) was developed by the Michigan Agricultural Experiment Station and released August 20, 2007, in an exclusive licensing agreement through Michigan State University (MSU) Technologies. Ambassador was selected from the cross of Pioneer Brand 27...

  1. REGISTRATION OF 'MASAMI' WHEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'Masami' soft white winter wheat (Triticum aestivum L.) (Reg. no. CV- , PI 634715) was developed by the Agricultural Research Center of Washington State University (WSU) in cooperation with the USDA-ARS. Masami was jointly released by Washington and Idaho Agricultural Experiment Stations and the ...

  2. REGISTRATION OF OTIS WHEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Otis hard white spring wheat (Triticum aestivum L.) (Reg. no. CV- 988, PI 634866) was developed and jointly released in August 2005 by the Agricultural Research Center of Washington State University in cooperation with the Agricultural Experiment Stations (AESs) of the University of Idaho and Oreg...

  3. REGISTRATION OF CHOPTANK WHEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Choptank (Reg. no. CV-976, PI 639724) is a soft red winter wheat (triticum aestivum L.) that was jointly developed and released by the Maryland Agricultural Experiment Station, Department of Natural Resource Sciences and Landscape Architecture, and the Virginia Agricultural Experiment Station in 2...

  4. Wheat allergy: diagnosis and management

    PubMed Central

    Cianferoni, Antonella

    2016-01-01

    Triticum aestivum (bread wheat) is the most widely grown crop worldwide. In genetically predisposed individuals, wheat can cause specific immune responses. A food allergy to wheat is characterized by T helper type 2 activation which can result in immunoglobulin E (IgE) and non-IgE mediated reactions. IgE mediated reactions are immediate, are characterized by the presence of wheat-specific IgE antibodies, and can be life-threatening. Non-IgE mediated reactions are characterized by chronic eosinophilic and lymphocytic infiltration of the gastrointestinal tract. IgE mediated responses to wheat can be related to wheat ingestion (food allergy) or wheat inhalation (respiratory allergy). A food allergy to wheat is more common in children and can be associated with a severe reaction such as anaphylaxis and wheat-dependent, exercise-induced anaphylaxis. An inhalation induced IgE mediated wheat allergy can cause baker’s asthma or rhinitis, which are common occupational diseases in workers who have significant repetitive exposure to wheat flour, such as bakers. Non-IgE mediated food allergy reactions to wheat are mainly eosinophilic esophagitis (EoE) or eosinophilic gastritis (EG), which are both characterized by chronic eosinophilic inflammation. EG is a systemic disease, and is associated with severe inflammation that requires oral steroids to resolve. EoE is a less severe disease, which can lead to complications in feeding intolerance and fibrosis. In both EoE and EG, wheat allergy diagnosis is based on both an elimination diet preceded by a tissue biopsy obtained by esophagogastroduodenoscopy in order to show the effectiveness of the diet. Diagnosis of IgE mediated wheat allergy is based on the medical history, the detection of specific IgE to wheat, and oral food challenges. Currently, the main treatment of a wheat allergy is based on avoidance of wheat altogether. However, in the near future immunotherapy may represent a valid way to treat IgE mediated reactions to wheat. PMID:26889090

  5. [Effects of wheat synomones on Macrosiphum avenae and its natural enemies].

    PubMed

    Ma, Xian-zhen; Wang, Wan-lei; Lu, Jin-qiu; Liu, Yong

    2008-01-01

    An investigation was made in winter wheat fields to study the effects of applying wheat synomones methyl salicylate and sulcatone (6-methy-5-hepten-2-one) on the dynamic changes of Macrosiphum avenae and its natural enemies Harmonia axyridis and Aphidius avenae. The results showed that wheat synomones didn' t change the population dynamics of M. avenae significantly, but had a significant effect on the reduction of M. avenae population number. The synomones could deteriorate the existent environment of M. avenae, and make the number of alatae increased obviously. Although synomones decreased the species richness, diversity index, and evenness of natural enemy communities, the numbers of dominant natural enemy species such as A. avenae and H axyridis were increased. Applying wheat synomones was helpful to the control of M. avenae in winter wheat fields. PMID:18419091

  6. Genetic control over silica deposition in wheat awns.

    PubMed

    Peleg, Zvi; Saranga, Yehoshua; Fahima, Tzion; Aharoni, Asaph; Elbaum, Rivka

    2010-09-01

    Awns are long, stiff filamentous extensions of glumes in many grasses. In wheat, awns contribute up to 40% of the grain's photosynthetic assimilates, and assist in seed dispersal. Awns accumulate silica in epidermal hairs and papillae, and silica has been positively associated with yield and environmental stress tolerance. Here, the awns of a set of domesticated wheat genotypes and their direct progenitor, Triticum turgidum ssp. dicoccoides were characterized. In addition, the silica concentration in awns was genetically dissected in a tetraploid wheat population of recombinant inbred lines (RILs) derived from a cross between durum wheat (cv. Langdon) and wild emmer (accession G18-16). Scanning electron micrographs revealed a continuous silica layer under the cuticle. Extended silicification was identified in the epidermis cell wall and in sclerenchyma cells near the vascular bundles, but not in the stomata, suggesting that an active process directs the soluble silica away from the water evaporation stream. The number of silicified cells was linearly correlated to silica concentration in dry weight (DW), suggesting cellular control over silicification. Domesticated wheat awns contained up to 19% silica per DW, as compared with 7% in the wild accessions, suggesting selection pressure associated with the domestication process. Six quantitative trait loci (QTLs) for silica were identified in the awns, with a LOD score of 3.7-6.3, three of which overlapped genomic regions that contribute to high grain protein. Localization of silica in the awns and identification of QTLs help illuminate mechanisms associated with silica metabolism in wheat. PMID:20444192

  7. Genetic analysis of wheat domestication and evolution under domestication

    PubMed Central

    Peleg, Zvi; Fahima, Tzion; Korol, Abraham B.; Abbo, Shahal; Saranga, Yehoshua

    2011-01-01

    Wheat is undoubtedly one of the world's major food sources since the dawn of Near Eastern agriculture and up to the present day. Morphological, physiological, and genetic modifications involved in domestication and subsequent evolution under domestication were investigated in a tetraploid recombinant inbred line population, derived from a cross between durum wheat and its immediate progenitor wild emmer wheat. Experimental data were used to test previous assumptions regarding a protracted domestication process. The brittle rachis (Br) spike, thought to be a primary characteristic of domestication, was mapped to chromosome 2A as a single gene, suggesting, in light of previously reported Br loci (homoeologous group 3), a complex genetic model involved in spike brittleness. Twenty-seven quantitative trait loci (QTLs) conferring threshability and yield components (kernel size and number of kernels per spike) were mapped. The large number of QTLs detected in this and other studies suggests that following domestication, wheat evolutionary processes involved many genomic changes. The Br gene did not show either genetic (co-localization with QTLs) or phenotypic association with threshability or yield components, suggesting independence of the respective loci. It is argued here that changes in spike threshability and agronomic traits (e.g. yield and its components) are the outcome of plant evolution under domestication, rather than the result of a protracted domestication process. Revealing the genomic basis of wheat domestication and evolution under domestication, and clarifying their inter-relationships, will improve our understanding of wheat biology and contribute to further crop improvement. PMID:21778183

  8. Impact of Solid and Hollow Varieties of Winter and Spring Wheat on Severity of Wheat Stem Sawfly (Hymenoptera: Cephidae) Infestations and Yield and Quality of Grain.

    PubMed

    Szczepaniec, Adrianna; Glover, Karl D; Berzonsky, William

    2015-10-01

    Wheat stem sawfly (WSS), Cephus cinctus Norton (Hymenoptera: Cephidae), has recently emerged as a key pest of wheat (Triticum aestivum L.) in the Great Plains and Canadian provinces. The expanding impact of WSS has caused considerable economic losses to wheat production. Solid-stem varieties of wheat remain the only effective measure of suppression of WSS, and the goal of this research was to test whether five solid- and hollow-stem varieties of winter and spring wheat reduce survival of WSS in South Dakota. We reported that solid-stem varieties had significantly lower numbers of WSS larvae, and this effect was especially evident when WSS infestation rates exceeded 15%. We also observed that the yield of solid-stem varieties was significantly lower than hollow-stem varieties when the abundance of WSS was low, but not when populations of WSS were relatively high. We did not observe consistent differences in grain quality between solid- and hollow-stem varieties, however, and in case of protein levels of grain, solid-stem wheat varieties performed better than hollow-stem wheat. We conclude that solid-stem varieties of wheat appear to effectively suppress WSS survival, and reduced yield of these varieties is less apparent when populations of C. cinctus are high enough to affect the yield of hollow-stem wheat. This is the first report to describe the effectiveness of solid-stem varieties of wheat on WSS in South Dakota. More research in the state is necessary before more robust conclusions can be drawn. PMID:26453720

  9. Wheat proteins in relation to protein requirements and availability of amino acids.

    PubMed

    Young, V R; Pellett, P L

    1985-05-01

    Wheat is a major source of plant protein for man. In parallel with other cereal staples, wheat proteins do not contain as high a concentration of the nutritionally indispensable amino acids as do animal protein foods. Thus, when consumed as an essentially sole source of protein they are not utilized with the same efficiency as animal protein foods and more wheat protein is required to meet the physiological needs in children and adults for both total protein and specific indispensable amino acids, especially lysine and also for threonine and tryptophan in specific cases. However, when combined with other food proteins such as legumes, oil seeds or animal products the proteins of wheat exhibit excellent nutritional complementarity. Furthermore, when wheat-based foods are considered in relation to broader concerns for diet, food habits and long-term health it is to be concluded that the proteins of wheat can and should continue to make a nutritionally important role toward meeting the protein and amino acid needs of populations throughout both the developing and developed regions of the world. Further research devoted toward improving the digestibility and overall nutritional value of wheat proteins and developing acceptable and economic sources of wheat protein concentrates should contribute to an even more substantial longterm role of wheat as a source of protein in human nutrition. PMID:3887888

  10. Genetic analysis of root morphological traits in wheat.

    PubMed

    Petrarulo, Maria; Marone, Daniela; Ferragonio, Pina; Cattivelli, Luigi; Rubiales, Diego; De Vita, Pasquale; Mastrangelo, Anna Maria

    2015-06-01

    Traits related to root architecture are of great importance for yield performance of crop species, although they remain poorly understood. The present study is aimed at identifying the genomic regions involved in the control of root morphological traits in durum wheat (Triticum durum Desf.). A set of 123 recombinant inbred lines derived from the durum wheat cross of cvs. 'Creso' × 'Pedroso' were grown hydroponically to two growth stages, and were phenotypically evaluated for a number of root traits. In addition, meta-(M)QTL analysis was performed that considered the results of other root traits studies in wheat, to compare with the 'Creso' × 'Pedroso' cross and to increase the QTL detection power. Eight quantitative trait loci (QTL) for traits related to root morphology were identified on chromosomes 1A, 1B, 2A, 3A, 6A and 6B in the 'Creso' × 'Pedroso' segregating population. Twenty-two MQTL that comprised from two to six individual QTL that had widely varying confidence intervals were found on 14 chromosomes. The data from the present study provide a detailed analysis of the genetic basis of morphological root traits in wheat. This study of the 'Creso' × 'Pedroso' durum-wheat population has revealed some QTL that had not been previously identified. PMID:25416422

  11. [Allelic Composition in the VRN-A1, VRN-B1, and VRN-B3 Genes of Double Haploid Lines of Hexaploid Triticale].

    PubMed

    Zaitseva, O I; Lemesh, V A

    2015-07-01

    Vernalization genes are associated with the adaptation capability, heading dates, and yield potential of grain crops. The allelic composition in the Vrn-A1, Vrn-B1, and Vrn-B3 genes was defined in 42 lines of double haploids of hexaploid triticale, which were produced through in vitro anther culture. Two alleles (Vrn-A1a and vrn-A1) were found at the Vrn-A1[ital] locus and three alleles (Vrn-B1a, Vrn-B1c, and vrn-B1) were found at the Vrn-B1 locus. All double haploids carried the recessive allele at the Vrn-B3[ital] locus. Twelve lines of spring triticale were selected, and they were characterized by an allelic composition associated with early maturity and high potential of grain yield. PMID:26410930

  12. Genomic prediction in CIMMYT maize and wheat breeding programs

    PubMed Central

    Crossa, J; Pérez, P; Hickey, J; Burgueño, J; Ornella, L; Cerón-Rojas, J; Zhang, X; Dreisigacker, S; Babu, R; Li, Y; Bonnett, D; Mathews, K

    2014-01-01

    Genomic selection (GS) has been implemented in animal and plant species, and is regarded as a useful tool for accelerating genetic gains. Varying levels of genomic prediction accuracy have been obtained in plants, depending on the prediction problem assessed and on several other factors, such as trait heritability, the relationship between the individuals to be predicted and those used to train the models for prediction, number of markers, sample size and genotype × environment interaction (GE). The main objective of this article is to describe the results of genomic prediction in International Maize and Wheat Improvement Center's (CIMMYT's) maize and wheat breeding programs, from the initial assessment of the predictive ability of different models using pedigree and marker information to the present, when methods for implementing GS in practical global maize and wheat breeding programs are being studied and investigated. Results show that pedigree (population structure) accounts for a sizeable proportion of the prediction accuracy when a global population is the prediction problem to be assessed. However, when the prediction uses unrelated populations to train the prediction equations, prediction accuracy becomes negligible. When genomic prediction includes modeling GE, an increase in prediction accuracy can be achieved by borrowing information from correlated environments. Several questions on how to incorporate GS into CIMMYT's maize and wheat programs remain unanswered and subject to further investigation, for example, prediction within and between related bi-parental crosses. Further research on the quantification of breeding value components for GS in plant breeding populations is required. PMID:23572121

  13. Genome-Wide Analysis of Microsatellite Markers Based on Sequenced Database in Chinese Spring Wheat (Triticum aestivum L.)

    PubMed Central

    Tang, Zhaohui; Ren, Yongkang; Li, Yali; Zhang, Dayong; Dong, Yanhui; Zhao, Xinghua

    2015-01-01

    Microsatellites or simple sequence repeats (SSRs) are distributed across both prokaryotic and eukaryotic genomes and have been widely used for genetic studies and molecular marker-assisted breeding in crops. Though an ordered draft sequence of hexaploid bread wheat have been announced, the researches about systemic analysis of SSRs for wheat still have not been reported so far. In the present study, we identified 364,347 SSRs from among 10,603,760 sequences of the Chinese spring wheat (CSW) genome, which were present at a density of 36.68 SSR/Mb. In total, we detected 488 types of motifs ranging from di- to hexanucleotides, among which dinucleotide repeats dominated, accounting for approximately 42.52% of the genome. The density of tri- to hexanucleotide repeats was 24.97%, 4.62%, 3.25% and 24.65%, respectively. AG/CT, AAG/CTT, AGAT/ATCT, AAAAG/CTTTT and AAAATT/AATTTT were the most frequent repeats among di- to hexanucleotide repeats. Among the 21 chromosomes of CSW, the density of repeats was highest on chromosome 2D and lowest on chromosome 3A. The proportions of di-, tri-, tetra-, penta- and hexanucleotide repeats on each chromosome, and even on the whole genome, were almost identical. In addition, 295,267 SSR markers were successfully developed from the 21 chromosomes of CSW, which cover the entire genome at a density of 29.73 per Mb. All of the SSR markers were validated by reverse electronic-Polymerase Chain Reaction (re-PCR); 70,564 (23.9%) were found to be monomorphic and 224,703 (76.1%) were found to be polymorphic. A total of 45 monomorphic markers were selected randomly for validation purposes; 24 (53.3%) amplified one locus, 8 (17.8%) amplified multiple identical loci, and 13 (28.9%) did not amplify any fragments from the genomic DNA of CSW. Then a dendrogram was generated based on the 24 monomorphic SSR markers among 20 wheat cultivars and three species of its diploid ancestors showing that monomorphic SSR markers represented a promising source to increase the number of genetic markers available for the wheat genome. The results of this study will be useful for investigating the genetic diversity and evolution among wheat and related species. At the same time, the results will facilitate comparative genomic studies and marker-assisted breeding (MAS) in plants. PMID:26536014

  14. Haplotype Detection from Next-Generation Sequencing in High-Ploidy-Level Species: 45S rDNA Gene Copies in the Hexaploid Spartina maritima

    PubMed Central

    Boutte, Julien; Aliaga, Benoît; Lima, Oscar; Ferreira de Carvalho, Julie; Ainouche, Abdelkader; Macas, Jiri; Rousseau-Gueutin, Mathieu; Coriton, Olivier; Ainouche, Malika; Salmon, Armel

    2015-01-01

    Gene and whole-genome duplications are widespread in plant nuclear genomes, resulting in sequence heterogeneity. Identification of duplicated genes may be particularly challenging in highly redundant genomes, especially when there are no diploid parents as a reference. Here, we developed a pipeline to detect the different copies in the ribosomal RNA gene family in the hexaploid grass Spartina maritima from next-generation sequencing (Roche-454) reads. The heterogeneity of the different domains of the highly repeated 45S unit was explored by identifying single nucleotide polymorphisms (SNPs) and assembling reads based on shared polymorphisms. SNPs were validated using comparisons with Illumina sequence data sets and by cloning and Sanger (re)sequencing. Using this approach, 29 validated polymorphisms and 11 validated haplotypes were reported (out of 34 and 20, respectively, that were initially predicted by our program). The rDNA domains of S. maritima have similar lengths as those found in other Poaceae, apart from the 5′-ETS, which is approximately two-times longer in S. maritima. Sequence homogeneity was encountered in coding regions and both internal transcribed spacers (ITS), whereas high intragenomic variability was detected in the intergenic spacer (IGS) and the external transcribed spacer (ETS). Molecular cytogenetic analysis by fluorescent in situ hybridization (FISH) revealed the presence of one pair of 45S rDNA signals on the chromosomes of S. maritima instead of three expected pairs for a hexaploid genome, indicating loss of duplicated homeologous loci through the diploidization process. The procedure developed here may be used at any ploidy level and using different sequencing technologies. PMID:26530424

  15. Haplotype Detection from Next-Generation Sequencing in High-Ploidy-Level Species: 45S rDNA Gene Copies in the Hexaploid Spartina maritima.

    PubMed

    Boutte, Julien; Aliaga, Benot; Lima, Oscar; Ferreira de Carvalho, Julie; Ainouche, Abdelkader; Macas, Jiri; Rousseau-Gueutin, Mathieu; Coriton, Olivier; Ainouche, Malika; Salmon, Armel

    2015-01-01

    Gene and whole-genome duplications are widespread in plant nuclear genomes, resulting in sequence heterogeneity. Identification of duplicated genes may be particularly challenging in highly redundant genomes, especially when there are no diploid parents as a reference. Here, we developed a pipeline to detect the different copies in the ribosomal RNA gene family in the hexaploid grass Spartina maritima from next-generation sequencing (Roche-454) reads. The heterogeneity of the different domains of the highly repeated 45S unit was explored by identifying single nucleotide polymorphisms (SNPs) and assembling reads based on shared polymorphisms. SNPs were validated using comparisons with Illumina sequence data sets and by cloning and Sanger (re)sequencing. Using this approach, 29 validated polymorphisms and 11 validated haplotypes were reported (out of 34 and 20, respectively, that were initially predicted by our program). The rDNA domains of S. maritima have similar lengths as those found in other Poaceae, apart from the 5'-ETS, which is approximately two-times longer in S. maritima. Sequence homogeneity was encountered in coding regions and both internal transcribed spacers (ITS), whereas high intragenomic variability was detected in the intergenic spacer (IGS) and the external transcribed spacer (ETS). Molecular cytogenetic analysis by fluorescent in situ hybridization (FISH) revealed the presence of one pair of 45S rDNA signals on the chromosomes of S. maritima instead of three expected pairs for a hexaploid genome, indicating loss of duplicated homeologous loci through the diploidization process. The procedure developed here may be used at any ploidy level and using different sequencing technologies. PMID:26530424

  16. Studies on the nutraceuticals composition of wheat derived oils wheat bran oil and wheat germ oil.

    PubMed

    Kumar, G Suresh; Krishna, A G Gopala

    2015-02-01

    Fat-soluble nutraceuticals of cereals are known for number of disease preventive activities. Hence wheat bran oil (WBO) and wheat germ oil (WGO) were extracted from wheat bran and germ which yielded 3.35% and 7.35% of oil, containing polyunsaturated fatty acids (PUFA) (64%, 61.2%) respectively. Both oils contained tocopherols and carotenoids, which were higher in wheat germ oil (273mg/100g, 12.23mg/100g) than wheat bran oil (190mg/100g, 2.21mg/100g). Steryl ferulates were also present in both the oils, but their content was eight-fold higher in WBO than in WGO. Three major steryl ferulates identified by HPLC were campesteryl ferulate and sitostenyl ferulate, campestanyl ferulate and ?-sitosteryl ferulate as in ?-oryzanol and another ferulate, viz., sitostanyl ferulate. A strong IC50 value of 7.5mg/mL and 21.6mg/mL DPPH free radicals scavenging for wheat germ oil for wheat bran oil was observed. NMR ((13)C and (1)H) profile explored the evidence of distribution of antioxidant molecules in the unsaponifiable matter of wheat derived oil. Since oils rich in PUFA and minor components are required for the normal physiological activities, blending such oils with other edible oils of the diet in wheat growing countries like India may be useful to provide health benefits. PMID:25694731

  17. Effect of storage and insect infestation on the mineral and vitamin contents of wheat grain and flour.

    PubMed

    Keskin, S; Ozkaya, H

    2013-04-01

    The objective of this study was to evaluate how storage and Sitophilus granarius L. infestation affects mineral and vitamin (thiamin and riboflavin) contents of wheat grain and flour obtained from the wheat. Wheat samples were infested with nonsexed S. granarius at a rate of two adults per kilogram, and stored for 6 mo at 30 +/- 1 degrees C and 70 +/- 5% relative humidity. Every 30 d, samples of wheat were collected and evaluated for insect population, mineral, thiamin, and riboflavin contents. Flour milled from these wheat samples was also evaluated for mineral, thiamin, and riboflavin contents. None of the analyses performed on the uninfested wheat and flour samples showed any noticeable change during the storage period. The insect population of the infested wheat samples increased during the storage period. The ratio of the mineral contents to dry matter significantly increased in the infested wheat and flour samples during the infestation period, whereas thiamin and riboflavin contents considerably decreased. The feeding habits of S. granarius and the distribution of minerals and vitamins in the wheat grain caused the changes observed in the levels of these compounds. The effects of infestation were greatest in the latter stages, during which the insect population increased greatly. PMID:23786101

  18. Whole-Genome Mapping of Agronomic and Metabolic Traits to Identify Novel Quantitative Trait Loci in Bread Wheat Grown in a Water-Limited Environment1[W][OA

    PubMed Central

    Hill, Camilla B.; Taylor, Julian D.; Edwards, James; Mather, Diane; Bacic, Antony; Langridge, Peter; Roessner, Ute

    2013-01-01

    Drought is a major environmental constraint responsible for grain yield losses of bread wheat (Triticum aestivum) in many parts of the world. Progress in breeding to improve complex multigene traits, such as drought stress tolerance, has been limited by high sensitivity to environmental factors, low trait heritability, and the complexity and size of the hexaploid wheat genome. In order to obtain further insight into genetic factors that affect yield under drought, we measured the abundance of 205 metabolites in flag leaf tissue sampled from plants of 179 cv Excalibur/Kukri F1-derived doubled haploid lines of wheat grown in a field experiment that experienced terminal drought stress. Additionally, data on 29 agronomic traits that had been assessed in the same field experiment were used. A linear mixed model was used to partition and account for nongenetic and genetic sources of variation, and quantitative trait locus analysis was used to estimate the genomic positions and effects of individual quantitative trait loci. Comparison of the agronomic and metabolic trait variation uncovered novel correlations between some agronomic traits and the levels of certain primary metabolites, including metabolites with either positive or negative associations with plant maturity-related or grain yield-related traits. Our analyses demonstrate that specific regions of the wheat genome that affect agronomic traits also have distinct effects on specific combinations of metabolites. This approach proved valuable for identifying novel biomarkers for the performance of wheat under drought and could facilitate the identification of candidate genes involved in drought-related responses in bread wheat. PMID:23660834

  19. [Non-celiac disease non-wheat allergy wheat sensitivity].

    PubMed

    Zopf, Yurdagl; Dieterich, Walburga

    2015-11-01

    Non-celiac non-wheat allergy wheat sensitivity is regarded as discrete glutensensitivity diagnosed after the exclusion of celiac disease and wheat allergy. Due to the absence of reliable biomarkers no exact prevalence rates are known and estimations range between 0,5-6?%. Soon after ingestion of wheat, patients complain of intestinal symptoms mainly bloating, abdominal pain, diarrhea or nausea which improve fast under glutenfree diet. Often extraintestinal manifestation as tiredness, muscle or joint pain, headache and depression are reported. Actually, there are no serological markers and no intestinal mucosal damage was found in patients. The underlying mechanism of the disease is completely unknown and beside of gluten other wheat proteins as well as amylase-trypsin-inhibitor or short chain sugars are discussed as triggers. In addition, the involvement of the intestinal microbiome in pathology of glutensensitivity must be considered. PMID:26536646

  20. Registration of 'Bill Brown' wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'Bill Brown’ (Reg. No. CV-133, PI 653260) hard red winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released in August 2007 through an exclusive marketing agreement with the Colorado Wheat Research Foundation. In addition to researchers at Colorad...

  1. Wheat Stripe Rust in China.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    China has the largest epidemic region in the world in terms of wheat acreage affected by stripe rust. Extensive studies on the epidemiology and management were carried out since the widespread occurrence in 1950s. Based on the factors influencing occurrence of wheat stripe rust, 15 epidemic zones w...

  2. Registration of 'Bill Brown' Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bill Brown (Reg. No. CV-133, PI 653260) hard red winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released in August 2007 through an exclusive marketing agreement with the Colorado Wheat Research Foundation. In addition to researchers at Colorad...

  3. BIOETHANOL PRODUCTION FROM WHEAT STRAW

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ethanol is a biobased oxygenated fuel. In the USA, the production of fuel ethanol from corn starch reached 4.0 billion gallons in 2005. Wheat straw, an abundant byproduct of wheat production, contains about 70% carbohydrates that can serve as a low cost feedstock for conversion to fuel ethanol. R...

  4. Registration of 'RB07' Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    RB07 (Reg. No. CV-1028, PI 652930) hard red spring wheat (Triticum aestivum L.) was developed by the University of Minnesota Agricultural Experiment Station and released in 2007. RB07 was tested as MN99436-6 in statewide yield trials from 2003 to 2006 and in the Uniform Hard Red Spring Wheat Regiona...

  5. Registration of 'LCS Wizard' wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this research was to develop widely adapted hard winter wheat (Triticum aestivum L.) varieties to meet the needs of mills, bakeries, and consumers in the eastern and Great Plains regions of the United States. LCS Wizard (Reg. No. CV-1111, PI 669574), a hard red winter (HRW) wheat,...

  6. Registration of 'Thunder CL' Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'Thunder CL' (Reg. No. CV- , PI XXXXXX) hard white winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released in August 2008 through a marketing agreement with the Colorado Wheat Research Foundation. In addition to researchers at Colorado State Uni...

  7. Registration of Appalachian White wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potential exists to develop and market hard winter wheat (Triticum aestivum L.) in the eastern United States, where a majority of the mills, bakeries, and consumers reside. The primary objective of this study was to develop adapted and competitive hard winter wheat cultivars possessing high-valu...

  8. Registration of Vision 40 Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potential exists to develop and market hard winter wheat (Triticum aestivum L.) in the eastern United States, where a majority of the mills, bakeries, and consumers reside. The primary objective of this study was to develop adapted and competitive hard winter wheat cultivars possessing high-valu...

  9. Virulence and biotype analyses of Hessian Fly (Mayetiola destructor) populations from Texas, Louisiana, and Oklahoma

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Hessian fly is a major pest of wheat, and is controlled mainly through deploying fly-resistant wheat cultivars. Changes in Hessian fly populations in the field may quickly overcome fly-resistance of wheat cultivars within a few years, thus continuous monitoring dynamics of Hessian fly populatio...

  10. HARD RED SPRING WHEAT - 2001 CROP

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA/ARS Hard Red Spring and Durum Wheat Quality Laboratory evaluated 16 cultivars of hard red spring (HRS) wheat from the 2001 crop for kernel and milling properties, and subsequently shipped flour (and/or wheat) to overseas cooperators through arrangements made by US Wheat Associates (USW) for...

  11. Hard Spring Wheat Technical Committee 2006 Crop

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Breeders experimental lines of wheat are evaluated for overall quality before being released for commercial production. The Hard Spring Wheat Technical Committee provides milling and baking quality data on breeders experimental lines of wheat that are annually submitted to the Wheat Quality Counc...

  12. BREEDING WHEAT FOR RESISTANCE TO INSECTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Host-plant resistance plays an important role in the management of the insect pests of wheat (Triticum sp.). Five pests, Hessian fly (Mayetiola destructor), Russian wheat aphid (Diuraphis noxia), wheat midge (Sitodiplosis mosellana), greenbug (Schizaphis graminum) and the wheat stem sawfly (Cephus s...

  13. How does wheat resistance mediated by H genes prevent manipulation of cell development by Hessian fly larvae?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The larva of the Hessian fly, Mayetiola destructor (Say) (Diptera: Cecidomyiidae), induces a gall nutritive tissue in susceptible wheat Triticum aestivum L. The nutritive tissue acts as a resource sink within the wheat seedling and causes serious crop losses. Hessian fly populations have been succes...

  14. Cultivar-dependent root colonization, antifungal metabolite accumulation and gene expression in the wheat-Pseudomonas interaction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We explored the role of host genotype in three aspects of the wheat-Pseudomonas biocontrol interaction: rhizosphere population density, accumulation of rhizosphere 2,4-diacetylphloroglucinol (DAPG), and Pseudomonas-mediated changes in root gene expression. Wheat cultivars varied in ability to suppo...

  15. Dissection and fine mapping of a major QTL for preharvest sprouting resistance in white wheat rio blanco

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Preharvest sprouting (PHS) is a major constraint to white wheat production. Previously, we mapped quantitative trait loci (QTL) for PHS resistance in white wheat by using a recombinant inbred line (RIL) population derived from the cross Rio Blanco/NW97S186. One QTL, QPhs.pseru-3A, showed a major eff...

  16. Preliminary assessment of resistance among U.S. wheat cultivars to the Triticum pathotype of Magnaporthe oryzae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Magnaporthe oryzae is the causal agent of blast disease on several graminaceous plants. The M. oryzae population causing wheat blast has not been officially reported outside South America. U.S. wheat production is at risk to this pathogen if it is introduced and established. Proactive testing of U.S...

  17. Genome-wide genetic dissection of supernumerary spikelet and related traits in common wheat (Triticum aestivum L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In wheat (Triticum aestivum L), exotic genotypes express a broad range of spike-related traits and could be used as a source of new genes to enrich the germplasm for wheat breeding programs. In the present study, a population of 163 recombinant inbred lines derived from a cross between an elite line...

  18. The expression of CBF genes at Fr-2 locus is associated with the level of frost tolerance in Bulgarian winter wheat cultivars

    PubMed Central

    Todorovska, Elena Georgieva; Kolev, Stanislav; Christov, Nikolai Kirilov; Balint, Andras; Kocsy, Gabor; Vágújfalvi, Attila; Galiba, Gabor

    2014-01-01

    The regulation of the majority of cold-regulated genes in plants is mediated by CBF (C-repeat binding factors) transcription factor family. Natural differences in frost tolerance (FT) of wheat have been mapped to the Fr-2 (Frost Resistance-2) locus on chromosome group 5 and are associated with variation in threshold induction temperatures and/or transcript levels of CBF genes. This study used real-time reverse-transcription polymerase chain reaction (qRT-PCR) to compare the relative expression levels of four T. aestivum CBF genes (TaCBF15.2, TaCBFA19, TaCBFA2 and TaCBFD21) in crown tissue of two Bulgarian hexaploid winter wheat cultivars (Milena and Russalka) with distinct levels of low-temperature (LT) tolerance but same vernalization requirement, and the spring cultivar Chinese Spring. The transcription profiles of the selected TaCBF genes showed that they are induced by cold treatment at 2 °C. Analysis of transcript abundance revealed that the four TaCBF genes were expressed at higher levels in the frost tolerant Milena than in the susceptible Russalka. Largest differences (fivefold and fourfold) in expression levels between both winter cultivars were observed in two of the analysed genes, TaCBF15.2 and TaCBFA19, respectively. The higher steady-state expression levels of TaCBF genes before the onset of the LT treatment in Milena, combined with stronger induction by cold treatment, suggest that these molecular responses to LT are associated with superior FT development capacity. The results expand our understanding of the molecular mechanisms underlying LT acclimation in Bulgarian wheat and can be used for development of functional markers for improvement of FT wheat-breeding programmes. PMID:26740761

  19. Alpha-amylase activity of Rhyzopertha dominica (Coleoptera: Bostrichidae) reared on several wheat varieties and its inhibition with kernel extracts.

    PubMed

    Cinco-Moroyoqui, Francisco J; Rosas-Burgos, Ema C; Borboa-Flores, Jess; Cortez-Rocha, Mario O

    2006-12-01

    Total progeny of Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) reared on 10 wheat, Triticum aestivum L., varieties was evaluated. Higher amylase activities were detected in populations with few individuals, whereas the opposite was observed in higher populations. As protein ingested increased, reproductive success increased. However, consumption of wheat protein was inversely correlated with amylase activity levels (r = -0.66). Amylase activity in homogenates of R. dominica populations showed variable inhibition by wheat extracts prepared from wheat varieties on which they were reared. Insect populations with lowest amylase activities were inhibited more by wheat extracts than those with higher amylase activity (r = -0.77). An electrophoretic analysis revealed four phenotypes showing combinations of three isoamylases (Rm 0.70, 0.79, and 0.90) in different populations of R. dominica. Some of the insect progeny that emerged from resistant wheat varieties contained the three isoamylases, whereas progeny that emerged from the most susceptible varieties showed reduced activity of isoamylases 0.70 or 0.90. These results suggest that the alpha-amylase activity levels and the composition of isoamylases in R. dominica populations are modulated by diet and that the alpha-amylase inhibitory activity of the wheat kernels influences these variations. PMID:17195686

  20. Wheat-related disorders: A broad spectrum of ‘evolving’ diseases

    PubMed Central

    Gasbarrini, GB

    2014-01-01

    Throughout the world, cereals have always been recognized as a fundamental food. Human evolution, through the development of cooking, led to the production of food rich in gluten, in order to take full advantage of the nutritional properties of this food. The result has been that gluten intolerance has arisen only in those populations that developed the art of cooking wheat. It is also recognized that wheat, one of the central elements of the Mediterranean diet, cannot be tolerated in some individuals. Among the wheat-related pathologies, coeliac disease is the best known: it is a chronic inflammatory condition affecting the gastrointestinal tract, which develops in genetically predisposed individuals. The most common manifestation is the malabsorption of nutrients. Recently, another wheat-related disease has appeared: non-coeliac gluten sensitivity, defined as the onset of a variety of manifestations related to wheat, rye and barley ingestion, in patients in whom coeliac disease and wheat allergy have been excluded. In this paper we will explore the damaging power of wheat, analysing the harmful process by which it realizes the onset of clinical manifestations associated with wheat-related disorders. PMID:25083282

  1. Characterization of a Low-Molecular-Weight Glutenin Subunit Gene from Bread Wheat and the Corresponding Protein That Represents a Major Subunit of the Glutenin Polymer1

    PubMed Central

    Masci, Stefania; D'Ovidio, Renato; Lafiandra, Domenico; Kasarda, Donald D.

    1998-01-01

    Both high- and low-molecular-weight glutenin subunits (LMW-GS) play the major role in determining the viscoelastic properties of wheat (Triticum aestivum L.) flour. To date there has been no clear correspondence between the amino acid sequences of LMW-GS derived from DNA sequencing and those of actual LMW-GS present in the endosperm. We have characterized a particular LMW-GS from hexaploid bread wheat, a major component of the glutenin polymer, which we call the 42K LMW-GS, and have isolated and sequenced the putative corresponding gene. Extensive amino acid sequences obtained directly for this 42K LMW-GS indicate correspondence between this protein and the putative corresponding gene. This subunit did not show a cysteine (Cys) at position 5, in contrast to what has frequently been reported for nucleotide-based sequences of LMW-GS. This Cys has been replaced by one occurring in the repeated-sequence domain, leaving the total number of Cys residues in the molecule the same as in various other LMW-GS. On the basis of the deduced amino acid sequence and literature-based assignment of disulfide linkages, a computer-generated molecular model of the 42K subunit was constructed. PMID:9847089

  2. Joint Transcriptomic and Metabolomic Analyses Reveal Changes in the Primary Metabolism and Imbalances in the Subgenome Orchestration in the Bread Wheat Molecular Response to Fusarium graminearum.

    PubMed

    Nussbaumer, Thomas; Warth, Benedikt; Sharma, Sapna; Ametz, Christian; Bueschl, Christoph; Parich, Alexandra; Pfeifer, Matthias; Siegwart, Gerald; Steiner, Barbara; Lemmens, Marc; Schuhmacher, Rainer; Buerstmayr, Hermann; Mayer, Klaus F X; Kugler, Karl G; Schweiger, Wolfgang

    2015-01-01

    Fusarium head blight is a prevalent disease of bread wheat (Triticum aestivum L.), which leads to considerable losses in yield and quality. Quantitative resistance to the causative fungus Fusarium graminearum is poorly understood. We integrated transcriptomics and metabolomics data to dissect the molecular response to the fungus and its main virulence factor, the toxin deoxynivalenol in near-isogenic lines segregating for two resistance quantitative trait loci, Fhb1 and Qfhs.ifa-5A. The data sets portrait rearrangements in the primary metabolism and the translational machinery to counter the fungus and the effects of the toxin and highlight distinct changes in the metabolism of glutamate in lines carrying Qfhs.ifa-5A. These observations are possibly due to the activity of two amino acid permeases located in the quantitative trait locus confidence interval, which may contribute to increased pathogen endurance. Mapping to the highly resolved region of Fhb1 reduced the list of candidates to few genes that are specifically expressed in presence of the quantitative trait loci and in response to the pathogen, which include a receptor-like protein kinase, a protein kinase, and an E3 ubiquitin-protein ligase. On a genome-scale level, the individual subgenomes of hexaploid wheat contribute differentially to defense. In particular, the D subgenome exhibited a pronounced response to the pathogen and contributed significantly to the overall defense response. PMID:26438291

  3. Joint Transcriptomic and Metabolomic Analyses Reveal Changes in the Primary Metabolism and Imbalances in the Subgenome Orchestration in the Bread Wheat Molecular Response to Fusarium graminearum

    PubMed Central

    Nussbaumer, Thomas; Warth, Benedikt; Sharma, Sapna; Ametz, Christian; Bueschl, Christoph; Parich, Alexandra; Pfeifer, Matthias; Siegwart, Gerald; Steiner, Barbara; Lemmens, Marc; Schuhmacher, Rainer; Buerstmayr, Hermann; Mayer, Klaus F. X.; Kugler, Karl G.; Schweiger, Wolfgang

    2015-01-01

    Fusarium head blight is a prevalent disease of bread wheat (Triticum aestivum L.), which leads to considerable losses in yield and quality. Quantitative resistance to the causative fungus Fusarium graminearum is poorly understood. We integrated transcriptomics and metabolomics data to dissect the molecular response to the fungus and its main virulence factor, the toxin deoxynivalenol in near-isogenic lines segregating for two resistance quantitative trait loci, Fhb1 and Qfhs.ifa-5A. The data sets portrait rearrangements in the primary metabolism and the translational machinery to counter the fungus and the effects of the toxin and highlight distinct changes in the metabolism of glutamate in lines carrying Qfhs.ifa-5A. These observations are possibly due to the activity of two amino acid permeases located in the quantitative trait locus confidence interval, which may contribute to increased pathogen endurance. Mapping to the highly resolved region of Fhb1 reduced the list of candidates to few genes that are specifically expressed in presence of the quantitative trait loci and in response to the pathogen, which include a receptor-like protein kinase, a protein kinase, and an E3 ubiquitin-protein ligase. On a genome-scale level, the individual subgenomes of hexaploid wheat contribute differentially to defense. In particular, the D subgenome exhibited a pronounced response to the pathogen and contributed significantly to the overall defense response. PMID:26438291

  4. Drought Tolerance in Wheat

    PubMed Central

    Prodhan, Zakaria Hossain; Faruq, Golam

    2013-01-01

    Drought is one of the most important phenomena which limit crops' production and yield. Crops demonstrate various morphological, physiological, biochemical, and molecular responses to tackle drought stress. Plants' vegetative and reproductive stages are intensively influenced by drought stress. Drought tolerance is a complicated trait which is controlled by polygenes and their expressions are influenced by various environmental elements. This means that breeding for this trait is so difficult and new molecular methods such as molecular markers, quantitative trait loci (QTL) mapping strategies, and expression patterns of genes should be applied to produce drought tolerant genotypes. In wheat, there are several genes which are responsible for drought stress tolerance and produce different types of enzymes and proteins for instance, late embryogenesis abundant (lea), responsive to abscisic acid (Rab), rubisco, helicase, proline, glutathione-S-transferase (GST), and carbohydrates during drought stress. This review paper has concentrated on the study of water limitation and its effects on morphological, physiological, biochemical, and molecular responses of wheat with the possible losses caused by drought stress. PMID:24319376

  5. Using multi-spectral imagery to detect and map stress induced by Russian wheat aphid

    NASA Astrophysics Data System (ADS)

    Backoulou, Georges Ferdinand

    Scope and Method of Study. The rationale of this study was to assess the stress in wheat field induced by the Russian wheat aphid using multispectral imagery. The study was conducted to (a) determine the relationship between RWA and edaphic and topographic factors; (b) identify and quantify the spatial pattern of RWA infestation within wheat fields; (c) differentiate the stress induced by RWA from other stress causing factors. Data used for the analysis included RWA population density from the wheat field in, Texas, Colorado, Wyoming, and Nebraska, Digital Elevation Model from the Unites States Geological Survey (USGS), soil data from the Soil Survey Geographic database (SSURGO), and multispectral imagery acquired in the panhandle of Oklahoma. Findings and Conclusions. The study revealed that the population density of the Russian wheat aphid was related to topographic and edaphic factors. Slope and sand were predictor variables that were positively related to the density of RWA at the field level. The study has also demonstrated that stress induced by the RWA has a specific spatial pattern that can be distinguished from other stress causing factors using a combination of landscape metrics and topographic and edaphic characteristics of wheat fields. Further field-based studies using multispectral imagery and spatial pattern analysis are suggested. The suggestions require acquiring biweekly multispectral imagery and collecting RWA, topographic and edaphic data at the sampling points during the phonological growth development of wheat plants. This is an approach that may pretend to have great potential for site specific technique for the integrated pest management.

  6. An Efficient Approach for the Development of Locus Specific Primers in Bread Wheat (Triticum aestivum L.) and Its Application to Re-Sequencing of Genes Involved in Frost Tolerance

    PubMed Central

    Babben, Steve; Perovic, Dragan; Koch, Michael; Ordon, Frank

    2015-01-01

    Recent declines in costs accelerated sequencing of many species with large genomes, including hexaploid wheat (Triticum aestivum L.). Although the draft sequence of bread wheat is known, it is still one of the major challenges to developlocus specific primers suitable to be used in marker assisted selection procedures, due to the high homology of the three genomes. In this study we describe an efficient approach for the development of locus specific primers comprising four steps, i.e. (i) identification of genomic and coding sequences (CDS) of candidate genes, (ii) intron- and exon-structure reconstruction, (iii) identification of wheat A, B and D sub-genome sequences and primer development based on sequence differences between the three sub-genomes, and (iv); testing of primers for functionality, correct size and localisation. This approach was applied to single, low and high copy genes involved in frost tolerance in wheat. In summary for 27 of these genes for which sequences were derived from Triticum aestivum, Triticum monococcum and Hordeum vulgare, a set of 119 primer pairs was developed and after testing on Nulli-tetrasomic (NT) lines, a set of 65 primer pairs (54.6%), corresponding to 19 candidate genes, turned out to be specific. Out of these a set of 35 fragments was selected for validation via Sanger's amplicon re-sequencing. All fragments, with the exception of one, could be assigned to the original reference sequence. The approach presented here showed a much higher specificity in primer development in comparison to techniques used so far in bread wheat and can be applied to other polyploid species with a known draft sequence. PMID:26565976

  7. Brazil wheat yield covariance model

    NASA Technical Reports Server (NTRS)

    Callis, S. L.; Sakamoto, C.

    1984-01-01

    A model based on multiple regression was developed to estimate wheat yields for the wheat growing states of Rio Grande do Sul, Parana, and Santa Catarina in Brazil. The meteorological data of these three states were pooled and the years 1972 to 1979 were used to develop the model since there was no technological trend in the yields during these years. Predictor variables were derived from monthly total precipitation, average monthly mean temperature, and average monthly maximum temperature.

  8. Genetic evidence for differential selection of grain and embryo weight during wheat evolution under domestication

    PubMed Central

    Golan, Guy; Oksenberg, Adi; Peleg, Zvi

    2015-01-01

    Wheat is one of the Neolithic founder crops domesticated ~10 500 years ago. Following the domestication episode, its evolution under domestication has resulted in various genetic modifications. Grain weight, embryo weight, and the interaction between those factors were examined among domesticated durum wheat and its direct progenitor, wild emmer wheat. Experimental data show that grain weight has increased over the course of wheat evolution without any parallel change in embryo weight, resulting in a significantly reduced (30%) embryo weight/grain weight ratio in domesticated wheat. The genetic factors associated with these modifications were further investigated using a population of recombinant inbred substitution lines that segregated for chromosome 2A. A cluster of loci affecting grain weight and shape was identified on the long arm of chromosome 2AL. Interestingly, a novel locus controlling embryo weight was mapped on chromosome 2AS, on which the wild emmer allele promotes heavier embryos and greater seedling vigour. To the best of our knowledge, this is the first report of a QTL for embryo weight in wheat. The results suggest a differential selection of grain and embryo weight during the evolution of domesticated wheat. It is argued that conscious selection by early farmers favouring larger grains and smaller embryos appears to have resulted in a significant change in endosperm weight/embryo weight ratio in the domesticated wheat. Exposing the genetic factors associated with endosperm and embryo size improves our understanding of the evolutionary dynamics of wheat under domestication and is likely to be useful for future wheat-breeding efforts. PMID:26019253

  9. Genetic evidence for differential selection of grain and embryo weight during wheat evolution under domestication.

    PubMed

    Golan, Guy; Oksenberg, Adi; Peleg, Zvi

    2015-09-01

    Wheat is one of the Neolithic founder crops domesticated ~10 500 years ago. Following the domestication episode, its evolution under domestication has resulted in various genetic modifications. Grain weight, embryo weight, and the interaction between those factors were examined among domesticated durum wheat and its direct progenitor, wild emmer wheat. Experimental data show that grain weight has increased over the course of wheat evolution without any parallel change in embryo weight, resulting in a significantly reduced (30%) embryo weight/grain weight ratio in domesticated wheat. The genetic factors associated with these modifications were further investigated using a population of recombinant inbred substitution lines that segregated for chromosome 2A. A cluster of loci affecting grain weight and shape was identified on the long arm of chromosome 2AL. Interestingly, a novel locus controlling embryo weight was mapped on chromosome 2AS, on which the wild emmer allele promotes heavier embryos and greater seedling vigour. To the best of our knowledge, this is the first report of a QTL for embryo weight in wheat. The results suggest a differential selection of grain and embryo weight during the evolution of domesticated wheat. It is argued that conscious selection by early farmers favouring larger grains and smaller embryos appears to have resulted in a significant change in endosperm weight/embryo weight ratio in the domesticated wheat. Exposing the genetic factors associated with endosperm and embryo size improves our understanding of the evolutionary dynamics of wheat under domestication and is likely to be useful for future wheat-breeding efforts. PMID:26019253

  10. Estimating climate change, CO2 and technology development effects on wheat yield in northeast Iran

    NASA Astrophysics Data System (ADS)

    Bannayan, M.; Mansoori, H.; Rezaei, E. Eyshi

    2014-04-01

    Wheat is the main food for the majority of Iran's population. Precise estimation of wheat yield change in future is essential for any possible revision of management strategies. The main objective of this study was to evaluate the effects of climate change, CO2 concentration, technology development and their integrated effects on wheat production under future climate change. This study was performed under two scenarios of the IPCC Special Report on Emission Scenarios (SRES): regional economic (A2) and global environmental (B1). Crop production was projected for three future time periods (2020, 2050 and 2080) in comparison with a baseline year (2005) for Khorasan province located in the northeast of Iran. Four study locations in the study area included Mashhad, Birjand, Bojnourd and Sabzevar. The effect of technology development was calculated by fitting a regression equation between the observed wheat yields against historical years considering yield potential increase and yield gap reduction as technology development. Yield relative increase per unit change of CO2 concentration (1 ppm-1) was considered 0.05 % and was used to implement the effect of elevated CO2. The HadCM3 general circulation model along with the CSM-CERES-Wheat crop model were used to project climate change effects on wheat crop yield. Our results illustrate that, among all the factors considered, technology development provided the highest impact on wheat yield change. Highest wheat yield increase across all locations and time periods was obtained under the A2 scenario. Among study locations, Mashhad showed the highest change in wheat yield. Yield change compared to baseline ranged from -28 % to 56 % when the integration of all factors was considered across all locations. It seems that achieving higher yield of wheat in future may be expected in northeast Iran assuming stable improvements in production technology.

  11. Estimating climate change, CO2 and technology development effects on wheat yield in northeast Iran.

    PubMed

    Bannayan, M; Mansoori, H; Rezaei, E Eyshi

    2014-04-01

    Wheat is the main food for the majority of Iran's population. Precise estimation of wheat yield change in future is essential for any possible revision of management strategies. The main objective of this study was to evaluate the effects of climate change, CO2 concentration, technology development and their integrated effects on wheat production under future climate change. This study was performed under two scenarios of the IPCC Special Report on Emission Scenarios (SRES): regional economic (A2) and global environmental (B1). Crop production was projected for three future time periods (2020, 2050 and 2080) in comparison with a baseline year (2005) for Khorasan province located in the northeast of Iran. Four study locations in the study area included Mashhad, Birjand, Bojnourd and Sabzevar. The effect of technology development was calculated by fitting a regression equation between the observed wheat yields against historical years considering yield potential increase and yield gap reduction as technology development. Yield relative increase per unit change of CO2 concentration (1ppm(-1)) was considered 0.05% and was used to implement the effect of elevated CO2. The HadCM3 general circulation model along with the CSM-CERES-Wheat crop model were used to project climate change effects on wheat crop yield. Our results illustrate that, among all the factors considered, technology development provided the highest impact on wheat yield change. Highest wheat yield increase across all locations and time periods was obtained under the A2 scenario. Among study locations, Mashhad showed the highest change in wheat yield. Yield change compared to baseline ranged from -28% to 56% when the integration of all factors was considered across all locations. It seems that achieving higher yield of wheat in future may be expected in northeast Iran assuming stable improvements in production technology. PMID:23397072

  12. Applications of Suits spectral model to wheat

    NASA Technical Reports Server (NTRS)

    Chance, J. E.

    1977-01-01

    Canopy reflectance calculations for a spring type Mexican wheat, Penjamo, are compared with published data on Scout winter wheat. Good agreement exists between model calculations and experimental data in the spectral range, 500 nm to 750 nm, suggesting that the model parameters for wheat can be applied to different cultivars of wheat in the same growth stage. Wheat canopy reflectance is dependent upon surface soil type and this dependency is examined with the Suits' spectral model. In this particular growth stage wheat reflectance is shown to be nearly independent of soil reflectance in the visible wavelengths and progressively dependent at longer wavelengths in the infrared.

  13. Dough Rheology and Wet Milling of Hard Waxy Wheat Flours

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To realize the full potential of waxy wheat (Triticum aestivum L.), wet milling of waxy wheat flour to produce gluten and waxy wheat starch was investigated. Flours of six advanced lines of waxy hard wheats, one normal hard wheat (‘Karl 92’), and one partial waxy wheat (‘Trego’) were fractionated by...

  14. 19 CFR 19.32 - Wheat manipulation; reconditioning.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Wheat manipulation; reconditioning. 19.32 Section... Bonded for the Storage of Wheat 19.32 Wheat manipulation; reconditioning. (a) The mixing, blending, or commingling of imported wheat and domestic wheat, or of imported wheat of different classes and grades, as...

  15. 19 CFR 19.32 - Wheat manipulation; reconditioning.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Wheat manipulation; reconditioning. 19.32 Section... Bonded for the Storage of Wheat 19.32 Wheat manipulation; reconditioning. (a) The mixing, blending, or commingling of imported wheat and domestic wheat, or of imported wheat of different classes and grades, as...

  16. 19 CFR 19.32 - Wheat manipulation; reconditioning.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Wheat manipulation; reconditioning. 19.32 Section... Bonded for the Storage of Wheat 19.32 Wheat manipulation; reconditioning. (a) The mixing, blending, or commingling of imported wheat and domestic wheat, or of imported wheat of different classes and grades, as...

  17. Linkage Disequilibrium and Genome-Wide Association Mapping in Tetraploid Wheat (Triticum turgidum L.)

    PubMed Central

    Laid, Giovanni; Marone, Daniela; Russo, Maria A.; Colecchia, Salvatore A.; Mastrangelo, Anna M.; De Vita, Pasquale; Papa, Roberto

    2014-01-01

    Association mapping is a powerful tool for the identification of quantitative trait loci through the exploitation of the differential decay of linkage disequilibrium (LD) between marker loci and genes of interest in natural and domesticated populations. Using a sample of 230 tetraploid wheat lines (Triticum turgidum ssp), which included naked and hulled accessions, we analysed the pattern of LD considering 26 simple sequence repeats and 970 mostly mapped diversity array technology loci. In addition, to validate the potential for association mapping in durum wheat, we evaluated the same genotypes for plant height, heading date, protein content, and thousand-kernel weight. Molecular and phenotypic data were used to: (i) investigate the genetic and phenotypic diversity; (ii) study the dynamics of LD across the durum wheat genome, by investigating the patterns of LD decay; and (iii) test the potential of our panel to identify markertrait associations through the analysis of four quantitative traits of major agronomic importance. Moreover, we compared and validated the association mapping results with outlier detection analysis based on population divergence. Overall, in tetraploid wheat, the pattern of LD is extremely population dependent and is related to the domestication and breeding history of durum wheat. Comparing our data with several other studies in wheat, we confirm the position of many major genes and quantitative trait loci for the traits considered. Finally, the analysis of the selection signature represents a very useful complement to validate markertrait associations. PMID:24759998

  18. SNP-revealed genetic diversity in wild emmer wheat correlates with ecological factors

    PubMed Central

    2013-01-01

    Background Patterns of genetic diversity between and within natural plant populations and their driving forces are of great interest in evolutionary biology. However, few studies have been performed on the genetic structure and population divergence in wild emmer wheat using a large number of EST-related single nucleotide polymorphism (SNP) markers. Results In the present study, twenty-five natural wild emmer wheat populations representing a wide range of ecological conditions in Israel and Turkey were used. Genetic diversity and genetic structure were investigated using over 1,000 SNP markers. A moderate level of genetic diversity was detected due to the biallelic property of SNP markers. Clustering based on Bayesian model showed that grouping pattern is related to the geographical distribution of the wild emmer wheat. However, genetic differentiation between populations was not necessarily dependent on the geographical distances. A total of 33 outlier loci under positive selection were identified using a FST-outlier method. Significant correlations between loci and ecogeographical factors were observed. Conclusions Natural selection appears to play a major role in generating adaptive structures in wild emmer wheat. SNP markers are appropriate for detecting selectively-channeled adaptive genetic diversity in natural populations of wild emmer wheat. This adaptive genetic diversity is significantly associated with ecological factors. PMID:23937410

  19. EVALUATION OF DURUM SPRING WHEAT SUSCEPTIBILITY TO WHEAT STEM SAWFLY (HYMENOPTERA: CEPHIDAE)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The wheat stem sawfly, Cephus cinctus Norton, is the primary arthropod pest of wheat, Triticum aestivum, in the Northern Great Plains. Rotation to non-host crops should decrease infestation of susceptible spring or winter wheats. Information is unavailable on wheat stem sawfly infestation potentia...

  20. Reflectance characteristics of Russian wheat aphid (Hemiptera: Aphididae) stress and abundance in winter wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Russian wheat aphid (Diuraphis noxia (Mordvilko)) infests wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and other small grains and grasses. Russian wheat aphid infestations are unpredictable in time and space. In favorable conditions, Russian wheat aphid feeding can result in heavy...

  1. Glycoproteins from Russian wheat aphid infested wheat induce defence responses.

    PubMed

    Lintle, Mohase; van der Westhuizen, Amie J

    2002-01-01

    Elicitors are molecules which can induce the activation of plant defence responses. Elicitor activity of intercellular wash fluid from Russian wheat aphid, Diuraphis noxia (Mordvilko) infested resistant (cv Tugela DN), and susceptible (cv Tugela), wheat (Triticum aestivum L.), was investigated. Known Russian wheat aphid resistance related responses such as peroxidase and beta-1,3-glucanase activities were used as parameters of elicitor activity. The intercellular wash fluid from infested resistant plants contains high elicitor activity while that from infested susceptible plants contains no or very little elicitor activity. After applying C-18 reverse phase and concanavalin A Sepharose chromatography, elicitor active glycoproteins were isolated from the intercellular wash fluid of Russian wheat aphid infested resistant wheat. The elicitor-active glycoproteins separated into three polypeptides during sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isolated glycoproteins elicited peroxidase activity to higher levels in resistant than in susceptible cultivars. It was evident that the glycoproteins were probably a general elicitor of plant origin. Information gained from these studies is valuable for the development of plant activators to enhance the defence responses of plants. PMID:12440726

  2. Ethanol production from mixtures of wheat straw and wheat meal

    PubMed Central

    2010-01-01

    Background Bioethanol can be produced from sugar-rich, starch-rich (first generation; 1G) or lignocellulosic (second generation; 2G) raw materials. Integration of 2G ethanol with 1G could facilitate the introduction of the 2G technology. The capital cost per ton of fuel produced would be diminished and better utilization of the biomass can be achieved. It would, furthermore, decrease the energy demand of 2G ethanol production and also provide both 1G and 2G plants with heat and electricity. In the current study, steam-pretreated wheat straw (SPWS) was mixed with presaccharified wheat meal (PWM) and converted to ethanol in simultaneous saccharification and fermentation (SSF). Results Both the ethanol concentration and the ethanol yield increased with increasing amounts of PWM in mixtures with SPWS. The maximum ethanol yield (99% of the theoretical yield, based on the available C6 sugars) was obtained with a mixture of SPWS containing 2.5% water-insoluble solids (WIS) and PWM containing 2.5% WIS, resulting in an ethanol concentration of 56.5 g/L. This yield was higher than those obtained with SSF of either SPWS (68%) or PWM alone (91%). Conclusions Mixing wheat straw with wheat meal would be beneficial for both 1G and 2G ethanol production. However, increasing the proportion of WIS as wheat straw and the possibility of consuming the xylose fraction with a pentose-fermenting yeast should be further investigated. PMID:20598120

  3. Image texture analysis of crushed wheat kernels

    NASA Astrophysics Data System (ADS)

    Zayas, Inna Y.; Martin, C. R.; Steele, James L.; Dempster, Richard E.

    1992-03-01

    The development of new approaches for wheat hardness assessment may impact the grain industry in marketing, milling, and breeding. This study used image texture features for wheat hardness evaluation. Application of digital imaging to grain for grading purposes is principally based on morphometrical (shape and size) characteristics of the kernels. A composite sample of 320 kernels for 17 wheat varieties were collected after testing and crushing with a single kernel hardness characterization meter. Six wheat classes where represented: HRW, HRS, SRW, SWW, Durum, and Club. In this study, parameters which characterize texture or spatial distribution of gray levels of an image were determined and used to classify images of crushed wheat kernels. The texture parameters of crushed wheat kernel images were different depending on class, hardness and variety of the wheat. Image texture analysis of crushed wheat kernels showed promise for use in class, hardness, milling quality, and variety discrimination.

  4. Effect of Wheat Flour Packaging Materials on Infestation by Lasioderma serricorne (F.).

    PubMed

    L, Jianhua; Ma, Dan

    2015-05-01

    The ability of the cigarette beetle, Lasioderma serricorne (F.) (Coleoptera: Anobiidae), to infest wheat flour under packaged and unpackaged conditions was investigated in the laboratory at 27 2C and 75% 5% relative humidity. Five common packaging materials, namely, vacuum plastic bags, kraft paper bags, nonwoven cloth bags, aluminum foil bags, and woven plastic bags, were investigated. Adults and eggs of L. serricorne were released on different packaged wheat flour or on unpackaged wheat flour, and infestation levels (number of live adults and larvae) were determined after 45 days. When adults were released on wheat flour, the infestation degree varied depending on the package materials. The highest infestation was observed in refined wheat flour packaged in nonwoven cloth bags. With wheat flour packaged in kraft paper bags exposed to adults or eggs, there was no insect infestation or insect infestation was negligible (mean population, <1.3). With wheat flour packaged in aluminum foil bags and vacuum plastic bags exposed to adults or eggs, there was no insect infestation. Damage to the packaging materials along the folds or edges was found in nonwoven cloth bags and woven plastic bags. Therefore, both aluminum foil and plastic bags had the greatest resistance to package invasion by L. serricorne. PMID:25951407

  5. Climate change induced rainfall patterns affect wheat productivity and agroecosystem functioning dependent on soil types

    NASA Astrophysics Data System (ADS)

    Tabi Tataw, James; Baier, Fabian; Krottenthaler, Florian; Pachler, Bernadette; Schwaiger, Elisabeth; Whylidal, Stefan; Formayer, Herbert; Hösch, Johannes; Baumgarten, Andreas; Zaller, Johann G.

    2014-05-01

    Wheat is a crop of global importance supplying more than half of the world's population with carbohydrates. We examined, whether climate change induced rainfall patterns towards less frequent but heavier events alter wheat agroecosystem productivity and functioning under three different soil types. Therefore, in a full-factorial experiment Triticum aestivum L. was cultivated in 3 m2 lysimeter plots containing the soil types sandy calcaric phaeozem, gleyic phaeozem or calcic chernozem. Prognosticated rainfall patterns based on regionalised climate change model calculations were compared with current long-term rainfall patterns; each treatment combination was replicated three times. Future rainfall patterns significantly reduced wheat growth and yield, reduced the leaf area index, accelerated crop development, reduced arbuscular mycorrhizal fungi colonisation of roots, increased weed density and the stable carbon isotope signature (δ13C) of both old and young wheat leaves. Different soil types affected wheat growth and yield, ecosystem root production as well as weed abundance and biomass. The interaction between climate and soil type was significant only for the harvest index. Our results suggest that even slight changes in rainfall patterns can significantly affect the functioning of wheat agroecosystems. These rainfall effects seemed to be little influenced by soil types suggesting more general impacts of climate change across different soil types. Wheat production under future conditions will likely become more challenging as further concurrent climate change factors become prevalent.

  6. H33: A wheat gene providing Hessian fly resistance for the southeastern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although more than 33 genes have been identified that confer resistance against Hessian fly attack in wheat, only five genes are currently effective against fly populations in the southeastern US. Because Hessian fly populations adapt to overcome newly deployed resistance genes within a few years of...

  7. Development of trispecies backcross populations using a 2(ADD) hexaploid bridging line to introgress genes from A-genome diploids into upland cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introgression of genes from A-genome diploid Gossypium species into tetraploid upland cotton is desirable but post-zygotic breeding barriers, in addition to ploidy differences, make the task difficult. G. arboreum L. and G. herbaceum L. accessions that had been previously identified as resistant to ...

  8. Stress-induced changes in wheat grain composition and quality.

    PubMed

    Ashraf, M

    2014-01-01

    Abiotic stresses such as drought, salinity, waterlogging, and high temperature cause a myriad of changes in the metabolism of plants, and there is a lot of overlap in these changes in plants in response to different stresses such as drought and salinity. These stress-induced metabolic changes cause impaired crop growth thereby resulting in poor yield. The metabolic changes taking place in several plant species due to a particular abiotic stress have been revealed from the whole plant to the molecular level by researchers, but most studies have focused on organs such as leaf, stem, and root. Information on such stress-induced changes in seed or grains is infrequent in the literature. From the information that is available, it is now evident that abiotic stress can induce considerable changes in the composition and quality of cereal grains including those of wheat, the premier staple food crop in the world. Thus, the present review discusses how far different types of stresses, mainly salinity, drought, high temperature, and waterlogging, can alter the wheat grain composition and quality. By fully uncovering the stress-induced changes in the nutritional values of wheat grains it would be possible to establish whether balanced supplies of essential nutrients are available to the human population from the wheat crop grown on stress-affected areas. PMID:24580559

  9. A genetic strategy generating wheat with very high amylose content.

    PubMed

    Regina, Ahmed; Berbezy, Pierre; Kosar-Hashemi, Behjat; Li, Suzhi; Cmiel, Mark; Larroque, Oscar; Bird, Anthony R; Swain, Steve M; Cavanagh, Colin; Jobling, Stephen A; Li, Zhongyi; Morell, Matthew

    2015-12-01

    Resistant starch (RS), a type of dietary fibre, plays an important role in human health; however, the content of RS in most modern processed starchy foods is low. Cereal starch, when structurally manipulated through a modified starch biosynthetic pathway to greatly increase the amylose content, could be an important food source of RS. Transgenic studies have previously revealed the requirement of simultaneous down-regulation of two starch branching enzyme (SBE) II isoforms both located on the long arm of chromosome 2, namely SBEIIa and SBEIIb, to elevate the amylose content in wheat from ~25% to ~75%. The current study revealed close proximity of genes encoding SBEIIa and SBEIIb isoforms in wheat with a genetic distance of 0.5cM on chromosome 2B. A series of deletion and single nucleotide polymorphism (SNP) loss of function alleles in SBEIIa, SBEIIb or both was isolated from two different wheat populations. A breeding strategy to combine deletions and SNPs generated wheat genotypes with altered expression levels of SBEIIa and SBEIIb, elevating the amylose content to an unprecedented ~85%, with a marked concomitant increase in RS content. Biochemical assays were used to confirm the complete absence in the grain of expression of SBEIIa from all three genomes in combination with the absence of SBEIIb from one of the genomes. PMID:25644858

  10. Evolution of bacterial communities in the wheat crop rhizosphere.

    PubMed

    Donn, Suzanne; Kirkegaard, John A; Perera, Geetha; Richardson, Alan E; Watt, Michelle

    2015-03-01

    The gap between current average global wheat yields and that achievable through best agronomic management and crop genetics is large. This is notable in intensive wheat rotations which are widely used. Expectations are that this gap can be reduced by manipulating soil processes, especially those that involve microbial ecology. Cross-year analysis of the soil microbiome in an intensive wheat cropping system revealed that rhizosphere bacteria changed much more than the bulk soil community. Dominant factors influencing populations included binding to roots, plant age, site and planting sequence. We demonstrated evolution of bacterial communities within the field rhizosphere. Early in the season, communities tightly bound to the root were simplest. These increased in diversity with plant age and senescence. Loosely bound communities also increased in diversity from vegetative to reproductive plant stages but were more stable than those tightly bound to roots. Planting sequence and, to a lesser extent, wheat genotype also significantly affected rhizosphere bacteria. Plasticity in the rhizosphere generated from crop root system management and genetics offers promise for manipulating the soil ecology of intense cereal systems. Analyses of soil microbiomes for the purpose of developing agronomic benefit should include roots as well as soil loosely adhered to the roots, and the bulk soil. PMID:24628845

  11. Floral Transformation of Wheat

    NASA Astrophysics Data System (ADS)

    Agarwal, Sujata; Loar, Star; Steber, Camille; Zale, Janice

    A method is described for the floral transformation of wheat using a protocol similar to the floral dip of Arabidopsis. This method does not employ tissue culture of dissected embryos, but instead pre-anthesis spikes with clipped florets at the early, mid to late uninucleate microspore stage are dipped in Agrobacterium infiltration media harboring a vector carrying anthocyanin reporters and the NPTII selectable marker. T1 seeds are examined for color changes induced in the embryo by the anthocyanin reporters. Putatively transformed seeds are germinated and the seedlings are screened for the presence of the NPTII gene based on resistance to paromomycin spray and assayed with NPTII ELISAs. Genomic DNA of putative transformants is digested and analyzed on Southern blots for copy number to determine whether the T-DNA has integrated into the nucleus and to show the number of insertions. The non-optimized transformation efficiencies range from 0.3 to 0.6% (number of transformants/number of florets dipped) but the efficiencies are higher in terms of the number of transformants produced/number of seeds set ranging from 0.9 to 10%. Research is underway to maximize seed set and optimize the protocol by testing different Agrobacterium strains, visual reporters, vectors, and surfactants.

  12. HARD SPRING WHEAT TECHNICAL COMMITTEE 2007 CROP

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twelve experimental lines of hard spring wheat were grown at up to five locations in 2007 and evaluated for kernel, milling, and bread baking quality against the check variety Glenn. Samples of wheat were submitted through the Wheat Quality Council and processed and milled at the USDA Hard Red Spri...

  13. Hard Spring Wheat Technical Committee, 2008 Crop.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eleven hard spring wheat lines that were developed by breeders throughout the spring wheat region of the U. S. were grown at up to five locations in 2008 and evaluated for kernel, milling, and bread baking quality against the check variety Glenn. Samples of wheat were milled at the USDA Hard Red Sp...

  14. Registration of 'UI Stone' spring wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soft white spring wheat (Triticum aestivumL.) is an important wheat class being used in domestic and international markets, especially in Idaho and Pacific Northwest (PNW). The objective of this study was to develop a SWS wheat cultivar with high grain yield, desirable end-use quality, and resistanc...

  15. The value of wheat landraces (Editorial)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whether man was domesticated by wheat, or wheat was domesticated by man is but two faces of the same coin; both incidents marked a turning point in human history and led to the emergence of human civilization in the Fertile Crescent of the Old World. The complex history of wheat domestication from i...

  16. Growing Wheat. People on the Farm.

    ERIC Educational Resources Information Center

    Department of Agriculture, Washington, DC. Office of Governmental and Public Affairs.

    This booklet, one in a series about life on modern farms, describes the daily life of the Don Riffel family, wheat farmers in Kansas. Beginning with early morning, the booklet traces the family's activities through a typical harvesting day in July, while explaining how a wheat farm is run. The booklet also briefly describes the wheat growing

  17. Hard Spring Wheat Technical Committee 2009 Crop

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirteen hard spring wheat lines that were developed by breeders throughout the spring wheat region of the U. S. were grown at up to five locations in 2009 and evaluated for kernel, milling, and bread baking quality against the check variety Glenn. Samples of wheat were milled at the USDA Hard Red ...

  18. Glycaemic index of Indian flatbreads (rotis) prepared using whole wheat flour and 'atta mix'-added whole wheat flour.

    PubMed

    Radhika, Ganesan; Sumathi, Chandhrasekar; Ganesan, Anbazhagan; Sudha, Vasudevan; Jeya Kumar Henry, Christiani; Mohan, Viswanathan

    2010-06-01

    To compare the glycaemic index (GI) of newly developed 'atta mix' roti with whole wheat flour roti. Eighteen healthy non-diabetic subjects consumed 50 g available carbohydrate portions of a reference food (glucose) and two test foods (whole wheat flour roti and atta mix roti) in random order after an overnight fast. The reference food was tested on three separate occasions, while the test foods were each tested once. Capillary blood samples were measured from finger-prick samples in fasted subjects ( - 5 and 0 min) and at 15, 30, 45, 60, 90 and 120 min from the start of each food. No significant difference was observed between roti prepared from whole wheat flour and atta mix in terms of appearance, texture, flavour, taste or acceptability. For each test food, the incremental area under the curve and GI values were determined. The GI of atta mix roti (27.3 (sem 2.2)) was considerably lower than the whole wheat flour roti (45.1 (sem 3.5), P < 0.001). Development of foods with lower dietary glycaemic load such as the atta mix roti could help in the prevention and control of diabetes in South Asian populations, which habitually consume very high glycaemic load diets. PMID:20100375

  19. Characterization of polyploid wheat genomic diversity using a high-density 90 000 single nucleotide polymorphism array

    PubMed Central

    Wang, Shichen; Wong, Debbie; Forrest, Kerrie; Allen, Alexandra; Chao, Shiaoman; Huang, Bevan E; Maccaferri, Marco; Salvi, Silvio; Milner, Sara G; Cattivelli, Luigi; Mastrangelo, Anna M; Whan, Alex; Stephen, Stuart; Barker, Gary; Wieseke, Ralf; Plieske, Joerg; International Wheat Genome Sequencing Consortium; Lillemo, Morten; Mather, Diane; Appels, Rudi; Dolferus, Rudy; Brown-Guedira, Gina; Korol, Abraham; Akhunova, Alina R; Feuillet, Catherine; Salse, Jerome; Morgante, Michele; Pozniak, Curtis; Luo, Ming-Cheng; Dvorak, Jan; Morell, Matthew; Dubcovsky, Jorge; Ganal, Martin; Tuberosa, Roberto; Lawley, Cindy; Mikoulitch, Ivan; Cavanagh, Colin; Edwards, Keith J; Hayden, Matthew; Akhunov, Eduard

    2014-01-01

    High-density single nucleotide polymorphism (SNP) genotyping arrays are a powerful tool for studying genomic patterns of diversity, inferring ancestral relationships between individuals in populations and studying marker–trait associations in mapping experiments. We developed a genotyping array including about 90 000 gene-associated SNPs and used it to characterize genetic variation in allohexaploid and allotetraploid wheat populations. The array includes a significant fraction of common genome-wide distributed SNPs that are represented in populations of diverse geographical origin. We used density-based spatial clustering algorithms to enable high-throughput genotype calling in complex data sets obtained for polyploid wheat. We show that these model-free clustering algorithms provide accurate genotype calling in the presence of multiple clusters including clusters with low signal intensity resulting from significant sequence divergence at the target SNP site or gene deletions. Assays that detect low-intensity clusters can provide insight into the distribution of presence–absence variation (PAV) in wheat populations. A total of 46 977 SNPs from the wheat 90K array were genetically mapped using a combination of eight mapping populations. The developed array and cluster identification algorithms provide an opportunity to infer detailed haplotype structure in polyploid wheat and will serve as an invaluable resource for diversity studies and investigating the genetic basis of trait variation in wheat. PMID:24646323

  20. Expression of a Thatcher wheat adult plant stem rust resistance QTL on chromosome arm 2BL is enhanced by Lr34

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An F6 recombinant inbred line (RIL) spring wheat population derived from RL6071, a stem rust susceptible line and RL6058, a backcross line of Thatcher wheat with Lr34 that is highly resistant to stem rust, was evaluated for adult plant stem rust resistance in North Dakota in 1999, and in Kenya in 20...

  1. Pyruvate orthophosphate dikinase in wheat leaves

    SciTech Connect

    Aoyagi, K.; Bassham, J.A.

    1983-01-01

    Pyruvate orthophosphate dikinase (PPDK) was found in wheat (Triticum aestivum L. cv Cheyenne (CI 8885)) leaves both by activity assays and by the protein blot method. The specific activity of the wheat enzyme is comparable to that of PPDK from maize leaves. Of the total soluble protein in wheat leaves, about 0.05% was PPDK, comparable to the amount in the immature wheat seed and about 1/70th the amount found in mesophyll cells of maize. Immunoprecipitation of wheat PPDK with maize enzyme antiserum indicates partial identity, and the apparent subunit molecular weight is the same based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

  2. A MOLECULAR MARKER MAP IN KANOTA X OGLE HEXAPLOID OAT (AVENA SP.) ENHANCED BY ADDITIONAL MARKERS AND A ROBUST FRAMEWORK

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molecular mapping of cultivated oats was conducted to update the previous reference map constructed using a recombinant inbred (RI) population derived from Avena byzantina C. Koch cv. 'Kanota' X A. sativa L. cv. 'Ogle.' In the current work, 607 new markers were scored, many on a larger set of RI lin...

  3. Biofortification of wheat grain with iron and zinc: integrating novel genomic resources and knowledge from model crops

    PubMed Central

    Borrill, Philippa; Connorton, James M.; Balk, Janneke; Miller, Anthony J.; Sanders, Dale; Uauy, Cristobal

    2014-01-01

    Wheat, like many other staple cereals, contains low levels of the essential micronutrients iron and zinc. Up to two billion people worldwide suffer from iron and zinc deficiencies, particularly in regions with predominantly cereal-based diets. Although wheat flour is commonly fortified during processing, an attractive and more sustainable solution is biofortification, which requires developing new varieties of wheat with inherently higher iron and zinc content in their grains. Until now most studies aimed at increasing iron and zinc content in wheat grains have focused on discovering natural variation in progenitor or related species. However, recent developments in genomics and transformation have led to a step change in targeted research on wheat at a molecular level. We discuss promising approaches to improve iron and zinc content in wheat using knowledge gained in model grasses. We explore how the latest resources developed in wheat, including sequenced genomes and mutant populations, can be exploited for biofortification. We also highlight the key research and practical challenges that remain in improving iron and zinc content in wheat. PMID:24600464

  4. Wheat Rusts in the United States in 2007

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2007 90% of wheat stem rust races were QFC and 10% were RCRS Both races are relatively avirulent to wheat cultiars grown in the U.S. Wheat stem rust occurred in scattered locations on research plots of susceptible wheat cultivars in 2007, and did not cause yield loss. Wheat leaf rust was widespr...

  5. Diseases Which Challenge Global Wheat Production - The Cereal Rusts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rusts of wheat are common and widespread diseases in the US and throughout the world. Wheat rusts have been important throughout the history of wheat cultivation and are currently important diseases that are responsible for regularly occurring yield losses in wheat. The wheat rust fungi are obli...

  6. 21 CFR 139.138 - Whole wheat macaroni products.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Whole wheat macaroni products. 139.138 Section 139... and Noodle Products 139.138 Whole wheat macaroni products. (a) Whole wheat macaroni products are the...)(3), and (g), except that: (1) Whole wheat flour or whole durum wheat flour or both are used as...

  7. 21 CFR 139.138 - Whole wheat macaroni products.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Whole wheat macaroni products. 139.138 Section 139... and Noodle Products 139.138 Whole wheat macaroni products. (a) Whole wheat macaroni products are the...)(3), and (g), except that: (1) Whole wheat flour or whole durum wheat flour or both are used as...

  8. 21 CFR 139.138 - Whole wheat macaroni products.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Whole wheat macaroni products. 139.138 Section 139... and Noodle Products 139.138 Whole wheat macaroni products. (a) Whole wheat macaroni products are the...)(3), and (g), except that: (1) Whole wheat flour or whole durum wheat flour or both are used as...

  9. Wheat genetics resource center: the first 25 years

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Wheat Genetics Resource Center, a pioneering center without walls, has served the wheat genetics community for 25 years. The Wheat Genetics Resource Center (WGRC) assembled a working collection of over 11,000 wild wheat relatives and cytogenetic stocks for conservation use in wheat genome analys...

  10. 21 CFR 139.138 - Whole wheat macaroni products.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Whole wheat macaroni products. 139.138 Section 139... and Noodle Products 139.138 Whole wheat macaroni products. (a) Whole wheat macaroni products are the...)(3), and (g), except that: (1) Whole wheat flour or whole durum wheat flour or both are used as...

  11. 21 CFR 139.138 - Whole wheat macaroni products.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Whole wheat macaroni products. 139.138 Section 139... and Noodle Products 139.138 Whole wheat macaroni products. (a) Whole wheat macaroni products are the...)(3), and (g), except that: (1) Whole wheat flour or whole durum wheat flour or both are used as...

  12. The microgeographical patterns of morphological and molecular variation of a mixed ploidy population in the species complex Actinidia chinensis.

    PubMed

    Liu, Yifei; Li, Dawei; Yan, Ling; Huang, Hongwen

    2015-01-01

    Polyploidy and hybridization are thought to have significant impacts on both the evolution and diversification of the genus Actinidia, but the structure and patterns of morphology and molecular diversity relating to ploidy variation of wild Actinidia plants remain much less understood. Here, we examine the distribution of morphological variation and ploidy levels along geographic and environmental variables of a large mixed-ploidy population of the A. chinensis species complex. We then characterize the extent of both genetic and epigenetic diversity and differentiation exhibited between individuals of different ploidy levels. Our results showed that while there are three ploidy levels in this population, hexaploids were constituted the majority (70.3%). Individuals with different ploidy levels were microgeographically structured in relation to elevation and extent of niche disturbance. The morphological characters examined revealed clear difference between diploids and hexaploids, however tetraploids exhibited intermediate forms. Both genetic and epigenetic diversity were high but the differentiation among cytotypes was weak, suggesting extensive gene flow and/or shared ancestral variation occurred in this population even across ploidy levels. Epigenetic variation was clearly correlated with changes in altitudes, a trend of continuous genetic variation and gradual increase of epigenomic heterogeneities of individuals was also observed. Our results show that complex interactions between the locally microgeographical environment, ploidy and gene flow impact A. chinensis genetic and epigenetic variation. We posit that an increase in ploidy does not broaden the species habitat range, but rather permits A. chinensis adaptation to specific niches. PMID:25658107

  13. The Microgeographical Patterns of Morphological and Molecular Variation of a Mixed Ploidy Population in the Species Complex Actinidia chinensis

    PubMed Central

    Liu, Yifei; Li, Dawei; Yan, Ling; Huang, Hongwen

    2015-01-01

    Polyploidy and hybridization are thought to have significant impacts on both the evolution and diversification of the genus Actinidia, but the structure and patterns of morphology and molecular diversity relating to ploidy variation of wild Actinidia plants remain much less understood. Here, we examine the distribution of morphological variation and ploidy levels along geographic and environmental variables of a large mixed-ploidy population of the A. chinensis species complex. We then characterize the extent of both genetic and epigenetic diversity and differentiation exhibited between individuals of different ploidy levels. Our results showed that while there are three ploidy levels in this population, hexaploids were constituted the majority (70.3%). Individuals with different ploidy levels were microgeographically structured in relation to elevation and extent of niche disturbance. The morphological characters examined revealed clear difference between diploids and hexaploids, however tetraploids exhibited intermediate forms. Both genetic and epigenetic diversity were high but the differentiation among cytotypes was weak, suggesting extensive gene flow and/or shared ancestral variation occurred in this population even across ploidy levels. Epigenetic variation was clearly correlated with changes in altitudes, a trend of continuous genetic variation and gradual increase of epigenomic heterogeneities of individuals was also observed. Our results show that complex interactions between the locally microgeographical environment, ploidy and gene flow impact A. chinensis genetic and epigenetic variation. We posit that an increase in ploidy does not broaden the species habitat range, but rather permits A. chinensis adaptation to specific niches. PMID:25658107

  14. DNA markers associated with low Fusarium head blight incidence and narrow flower opening in wheat.

    PubMed

    Gilsinger, J; Kong, L; Shen, X; Ohm, H

    2005-05-01

    Fusarium head blight (FHB) of wheat, caused by Fusarium graminearum, is an important fungal disease in many wheat-growing areas of the world. The objectives of this study were to determine the relationship between width and duration of flower opening and incidence of FHB in wheat, and to identify DNA markers associated with narrow flower opening and low FHB incidence. It was hypothesized that wheat lines whose flowers open briefly and narrowly have a reduced risk of infection. To test the hypothesis, we crossed wheat cultivars Patterson and Goldfield to generate a population of 100 random F(2)-derived recombinant inbred lines (RILs). Florets of Patterson open wide; florets of Goldfield tend to stay closed. The population of RILs was characterized for FHB incidence and flower opening width (FOW) and duration in the F(7:9) and F(7:10) generations. Of the 305 simple sequence repeat primer pairs screened on the parents, 79 amplified polymorphic DNA bands. Pooled DNA from each of the two bulks was tested with these 79 SSR primer pairs. Four markers were found to have significant marker-trait association with low FHB incidence and narrow flower opening. The major QTL effect associated with narrow flower opening and low FHB incidence was found between the map interval Xbarc200-Xgwm210, explaining 29% of the phenotypic variation for FHB incidence averaged over six replicated tests in Indiana in 2002 and 2003. This adds credence to the hypothesis that narrow flower opening is responsible for low FHB incidence in this population. Breeding wheat lines for both morphological avoidance, such as narrow flower opening, and physiological resistance to FHB may be valuable in future breeding research to reduce crop production and grain quality losses in wheat due to FHB. PMID:15750825

  15. Registration of 'TAM 113' wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    TAM 113 (Reg. No. CV-1081, PI 666125), a hard red winter wheat (Triticum aestivum L.) cultivar with experimental designation TX02A0252, was developed and released by Texas AgriLife Research in 2010. TAM 113 is an F5derived line from the cross TX90V6313/TX94V3724 made at Vernon, TX in 1995. Both T...

  16. Registration of 'NE01643' Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    NE01643 is a hard red winter wheat (Triticum aestivum L.) cultivar developed cooperatively by the Nebraska Agricultural Experiment Station and the USDA-ARS and released in 2007 by the developing institutions and the South Dakota Agricultural Experiment Station. NE01643 will be marketed under the na...

  17. Registration of OK Bullet Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    OK Bullet (Reg. No. CV-999, PI 642415) is a hard red winter (HRW) wheat (Triticum aestivum L.) cultivar developed cooperatively by the Oklahoma Agric. Exp. Stn. (AES), USDA-ARS, and the Texas AES and released by the Oklahoma AES and the USDA-ARS in 2005. OK Bullet is recommended for grain-only and...

  18. REGISTRATION OF 'OK BULLET' WHEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    OK Bullet is a hard red winter wheat (Triticum aestivum L.) cultivar developed cooperatively by the Oklahoma Agric. Exp. Stn. (AES), USDA-ARS, and the Texas AES and released by the Oklahoma AES and the USDA-ARS in 2005. OK Bullet is recommended for grain-only and dual-purpose production systems t...

  19. Registration of Faller Spring Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Faller (Reg. No. CV-1026, PI 648350) hard red spring wheat (HRSW) (Triticum aestivum L.) was developed at North Dakota State University(NDSU) and released by the North Dakota Agricultural Experiment Station (NDAES). Faller was derived from the ND2857/ND2814 cross made at NDSU in fall 1997. ND2857 ...

  20. Registration of Vision 30 Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Vision 30’ (Reg. No. CV-1062, PI 661153) hard red winter (HRW) wheat (Triticum aestivum L.) was developed and tested as VA06HRW-49 and released by the Virginia Agricultural Experiment Station in March 2010. Vision 30 was derived from the cross 92PAN1#33/VA97W-414. Vision 30 is high yielding, awned,...