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Sample records for aegilops tauschii coss

  1. Hypersensitive Response-Like Reaction Is Associated with Hybrid Necrosis in Interspecific Crosses between Tetraploid Wheat and Aegilops tauschii Coss

    PubMed Central

    Mizuno, Nobuyuki; Hosogi, Naoki; Park, Pyoyun; Takumi, Shigeo

    2010-01-01

    Background Hybrid speciation is classified into homoploid and polyploid based on ploidy level. Common wheat is an allohexaploid species that originated from a naturally occurring interploidy cross between tetraploid wheat and diploid wild wheat Aegilops tauschii Coss. Aegilops tauschii provides wide naturally occurring genetic variation. Sometimes its triploid hybrids with tetraploid wheat show the following four types of hybrid growth abnormalities: types II and III hybrid necrosis, hybrid chlorosis, and severe growth abortion. The growth abnormalities in the triploid hybrids could act as postzygotic hybridization barriers to prevent formation of hexaploid wheat. Methodology/Principal Findings Here, we report on the geographical and phylogenetic distribution of Ae. tauschii accessions inducing the hybrid growth abnormalities and showed that they are widely distributed across growth habitats in Ae. tauschii. Molecular and cytological characterization of the type III necrosis phenotype was performed. The hybrid abnormality causing accessions were widely distributed across growth habitats in Ae. tauschii. Transcriptome analysis showed that a number of defense-related genes such as pathogenesis-related genes were highly up-regulated in the type III necrosis lines. Transmission electron microscope observation revealed that cell death occurred accompanied by generation of reactive oxygen species in leaves undergoing type III necrosis. The reduction of photosynthetic activity occurred prior to the appearance of necrotic symptoms on the leaves exhibiting hybrid necrosis. Conclusions/Significance Taking these results together strongly suggests that an autoimmune response might be triggered by intergenomic incompatibility between the tetraploid wheat and Ae. tauschii genomes in type III necrosis, and that genetically programmed cell death could be regarded as a hypersensitive response-like cell death similar to that observed in Arabidopsis intraspecific and Nicotiana

  2. Strategy for exploiting exotic germplasm using genetic, morphological, and environmental diversity: the Aegilops tauschii Coss. example.

    PubMed

    Jones, H; Gosman, N; Horsnell, R; Rose, G A; Everest, L A; Bentley, A R; Tha, S; Uauy, C; Kowalski, A; Novoselovic, D; Simek, R; Kobiljski, B; Kondic-Spika, A; Brbaklic, L; Mitrofanova, O; Chesnokov, Y; Bonnett, D; Greenland, A

    2013-07-01

    Hexaploid bread wheat evolved from a rare hybridisation, which resulted in a loss of genetic diversity in the wheat D-genome with respect to the ancestral donor, Aegilops tauschii. Novel genetic variation can be introduced into modern wheat by recreating the above hybridisation; however, the information associated with the Ae. tauschii accessions in germplasm collections is limited, making rational selection of accessions into a re-synthesis programme difficult. We describe methodologies to identify novel diversity from Ae. tauschii accessions that combines Bayesian analysis of genotypic data, sub-species diversity and geographic information that summarises variation in climate and habitat at the collection point for each accession. Comparisons were made between diversity discovered amongst a panel of Ae. tauschii accessions, bread wheat varieties and lines from the CIMMYT synthetic hexaploid wheat programme. The selection of Ae. tauschii accessions based on differing approaches had significant effect on diversity within each set. Our results suggest that a strategy that combines several criteria will be most effective in maximising the sampled variation across multiple parameters. The analysis of multiple layers of variation in ex situ Ae. tauschii collections allows for an informed and rational approach to the inclusion of wild relatives into crop breeding programmes. PMID:23558983

  3. Effective transfer of chromosomes carrying leaf rust resistance genes from Aegilops tauschii Coss. into hexaploid triticale (X Triticosecale Witt.) using Ae. tauschii × Secale cereale amphiploid forms.

    PubMed

    Kwiatek, Michał; Majka, Maciej; Wiśniewska, Halina; Apolinarska, Barbara; Belter, Jolanta

    2015-05-01

    This paper shows the results of effective uses of a molecular cytogenetics toolbox and molecular marker to transfer leaf rust resistance genes from Aegilops tauschii × Secale cereale (DDRR, 2n = 4x = 28) amphiploid forms to triticale cv. Bogo (AABBRR, 2n = 6x = 42). The molecular markers of resistance genes and in situ hybridization analysis of mitotic metaphase of root meristems confirmed the stable inheritance of chromosome 3D segments carrying Lr32 from the BC2F2 to the BC2F5 generation of (Ae. tauschii × S. cereale) × triticale hybrids. The chromosome pairing analysis during metaphase I of meiosis of BC2F4 and BC2F5 hybrids showed increasing regular bivalent formation of 3D chromosome pairs and decreasing number of univalents in subsequent generations. The results indicate that using amphiploid forms as a bridge between wild and cultivated forms can be a successful technology to transfer the D-genome chromatin carrying leaf rust resistance genes into triticale. PMID:25502891

  4. 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...

  5. [Genetic analysis and SSR mapping on an new stem stripe rust resistance gene YrY206 in Aegilops tauschii].

    PubMed

    Zhang, Haiquan; Lang, Jie; Ma, Shuqin; Zhang, Baoshi

    2008-08-01

    A wheat stripe rust resistance gene was screened out from Aegilops tauschii which is relative genera of wheat species, broadening the genetic basis of the anti-disease character of wheat species. By hybridizing diversed Ae. Tauschii species, which is either resistant or susceptible to wheat stripe rust, a dominant wheat stripe rust resistance gene was detected from Ae. Tauschii (Coss.) Schmal Y206. The novel gene was temporarily designated as YrY206. By bulk segregation analysis, four microsatellite markers Wmc11a, Xgwm71c, Xgwm161 and Xgwm183 were found to be linked to YrY206 with genetic distances of 4.0, 3.3, 1.5 and 9.3 cM, respectively. According to the locations of the linked markers, the resistance gene was located on chromosome 3DS. Based on the chromosomal location and the resistance pattern of the gene, YrY206 should be a novel stripe rust resistance gene. PMID:18998554

  6. Introgression of stem rust resistance genes SrTA10187 and SrTA10171 from Aegilops tauschii to wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diploid progenitor of the wheat D genome, Aegilops tauschii, has provided a wealth of genes for resistance to many diseases and insect pests of wheat. Ae. tauschii is a readily accessible pool of genes for wheat breeding as genes can be transferred to elite wheat cultivars though direct hybridi...

  7. BAC libraries of Triticum urartu, Aegilops speltoides and Ae. tauschii, the diploid ancestors of polyploid wheat.

    PubMed

    Akhunov, E D; Akhunova, A R; Dvorák, J

    2005-11-01

    Triticum urartu, Aegilops speltoides and Ae. tauschii are respectively the immediate diploid sources, or their closest relatives, of the A, B and D genomes of polyploid wheats. Here we report the construction and characterization of arrayed large-insert libraries in a bacterial artificial chromosome (BAC) vector, one for each of these diploid species. The libraries are equivalent to 3.7, 5.4 and 4.1 of the T. urartu, Ae. speltoides, Ae. tauschii genomes, respectively. The predicted levels of genome coverage were confirmed by library hybridization with single-copy genes. The libraries were used to estimate the proportion of known repeated nucleotide sequences and gene content in each genome by BAC-end sequencing. Repeated sequence families previously detected in Triticeae accounted for 57, 61 and 57% of the T. urartu, Ae. speltoides and Ae. tauschii genomes, and coding regions accounted for 5.8, 4.5 and 4.8%, respectively. PMID:16177898

  8. Dissecting miRNAs in Wheat D Genome Progenitor, Aegilops tauschii.

    PubMed

    Akpinar, Bala A; Budak, Hikmet

    2016-01-01

    As the post-transcriptional regulators of gene expression, microRNAs or miRNAs comprise an integral part of understanding how genomes function. Although miRNAs have been a major focus of recent efforts, miRNA research is still in its infancy in most plant species. Aegilops tauschii, the D genome progenitor of bread wheat, is a wild diploid grass exhibiting remarkable population diversity. Due to the direct ancestry and the diverse gene pool, A. tauschii is a promising source for bread wheat improvement. In this study, a total of 87 Aegilops miRNA families, including 51 previously unknown, were computationally identified both at the subgenomic level, using flow-sorted A. tauschii 5D chromosome, and at the whole genome level. Predictions at the genomic and subgenomic levels suggested A. tauschii 5D chromosome as rich in pre-miRNAs that are highly associated with Class II DNA transposons. In order to gain insights into miRNA evolution, putative 5D chromosome miRNAs were compared to its modern ortholog, Triticum aestivum 5D chromosome, revealing that 48 of the 58 A. tauschii 5D miRNAs were conserved in orthologous T. aestivum 5D chromosome. The expression profiles of selected miRNAs (miR167, miR5205, miR5175, miR5523) provided the first experimental evidence for miR5175, miR5205 and miR5523, and revealed differential expressional changes in response to drought in different genetic backgrounds for miR167 and miR5175. Interestingly, while miR5523 coding regions were present and expressed as pre-miR5523 in both T. aestivum and A. tauschii, the expression of mature miR5523 was observed only in A. tauschii under normal conditions, pointing out to an interference at the downstream processing of pre-miR5523 in T. aestivum. Overall, this study expands our knowledge on the miRNA catalog of A. tauschii, locating a subset specifically to the 5D chromosome, with ample functional and comparative insight which should contribute to and complement efforts to develop drought tolerant

  9. Dissecting miRNAs in Wheat D Genome Progenitor, Aegilops tauschii

    PubMed Central

    Akpinar, Bala A.; Budak, Hikmet

    2016-01-01

    As the post-transcriptional regulators of gene expression, microRNAs or miRNAs comprise an integral part of understanding how genomes function. Although miRNAs have been a major focus of recent efforts, miRNA research is still in its infancy in most plant species. Aegilops tauschii, the D genome progenitor of bread wheat, is a wild diploid grass exhibiting remarkable population diversity. Due to the direct ancestry and the diverse gene pool, A. tauschii is a promising source for bread wheat improvement. In this study, a total of 87 Aegilops miRNA families, including 51 previously unknown, were computationally identified both at the subgenomic level, using flow-sorted A. tauschii 5D chromosome, and at the whole genome level. Predictions at the genomic and subgenomic levels suggested A. tauschii 5D chromosome as rich in pre-miRNAs that are highly associated with Class II DNA transposons. In order to gain insights into miRNA evolution, putative 5D chromosome miRNAs were compared to its modern ortholog, Triticum aestivum 5D chromosome, revealing that 48 of the 58 A. tauschii 5D miRNAs were conserved in orthologous T. aestivum 5D chromosome. The expression profiles of selected miRNAs (miR167, miR5205, miR5175, miR5523) provided the first experimental evidence for miR5175, miR5205 and miR5523, and revealed differential expressional changes in response to drought in different genetic backgrounds for miR167 and miR5175. Interestingly, while miR5523 coding regions were present and expressed as pre-miR5523 in both T. aestivum and A. tauschii, the expression of mature miR5523 was observed only in A. tauschii under normal conditions, pointing out to an interference at the downstream processing of pre-miR5523 in T. aestivum. Overall, this study expands our knowledge on the miRNA catalog of A. tauschii, locating a subset specifically to the 5D chromosome, with ample functional and comparative insight which should contribute to and complement efforts to develop drought tolerant

  10. Genome-wide association study of drought-related resistance traits in Aegilops tauschii

    PubMed Central

    Qin, Peng; Lin, Yu; Hu, Yaodong; Liu, Kun; Mao, Shuangshuang; Li, Zhanyi; Wang, Jirui; Liu, Yaxi; Wei, Yuming; Zheng, Youliang

    2016-01-01

    Abstract The D-genome progenitor of wheat (Triticum aestivum), Aegilops tauschii, possesses numerous genes for resistance to abiotic stresses, including drought. Therefore, information on the genetic architecture of A. tauschii can aid the development of drought-resistant wheat varieties. Here, we evaluated 13 traits in 373 A. tauschii accessions grown under normal and polyethylene glycol-simulated drought stress conditions and performed a genome-wide association study using 7,185 single nucleotide polymorphism (SNP) markers. We identified 208 and 28 SNPs associated with all traits using the general linear model and mixed linear model, respectively, while both models detected 25 significant SNPs with genome-wide distribution. Public database searches revealed several candidate/flanking genes related to drought resistance that were grouped into three categories according to the type of encoded protein (enzyme, storage protein, and drought-induced protein). This study provided essential information for SNPs and genes related to drought resistance in A. tauschii and wheat, and represents a foundation for breeding drought-resistant wheat cultivars using marker-assisted selection. PMID:27560650

  11. Genome-wide association study of drought-related resistance traits in Aegilops tauschii.

    PubMed

    Qin, Peng; Lin, Yu; Hu, Yaodong; Liu, Kun; Mao, Shuangshuang; Li, Zhanyi; Wang, Jirui; Liu, Yaxi; Wei, Yuming; Zheng, Youliang

    2016-07-01

    The D-genome progenitor of wheat (Triticum aestivum), Aegilops tauschii, possesses numerous genes for resistance to abiotic stresses, including drought. Therefore, information on the genetic architecture of A. tauschii can aid the development of drought-resistant wheat varieties. Here, we evaluated 13 traits in 373 A. tauschii accessions grown under normal and polyethylene glycol-simulated drought stress conditions and performed a genome-wide association study using 7,185 single nucleotide polymorphism (SNP) markers. We identified 208 and 28 SNPs associated with all traits using the general linear model and mixed linear model, respectively, while both models detected 25 significant SNPs with genome-wide distribution. Public database searches revealed several candidate/flanking genes related to drought resistance that were grouped into three categories according to the type of encoded protein (enzyme, storage protein, and drought-induced protein). This study provided essential information for SNPs and genes related to drought resistance in A. tauschii and wheat, and represents a foundation for breeding drought-resistant wheat cultivars using marker-assisted selection. PMID:27392238

  12. Genome-wide association study of drought-related resistance traits in Aegilops tauschii.

    PubMed

    Qin, Peng; Lin, Yu; Hu, Yaodong; Liu, Kun; Mao, Shuangshuang; Li, Zhanyi; Wang, Jirui; Liu, Yaxi; Wei, Yuming; Zheng, Youliang

    2016-01-01

    The D-genome progenitor of wheat (Triticum aestivum), Aegilops tauschii, possesses numerous genes for resistance to abiotic stresses, including drought. Therefore, information on the genetic architecture of A. tauschii can aid the development of drought-resistant wheat varieties. Here, we evaluated 13 traits in 373 A. tauschii accessions grown under normal and polyethylene glycol-simulated drought stress conditions and performed a genome-wide association study using 7,185 single nucleotide polymorphism (SNP) markers. We identified 208 and 28 SNPs associated with all traits using the general linear model and mixed linear model, respectively, while both models detected 25 significant SNPs with genome-wide distribution. Public database searches revealed several candidate/flanking genes related to drought resistance that were grouped into three categories according to the type of encoded protein (enzyme, storage protein, and drought-induced protein). This study provided essential information for SNPs and genes related to drought resistance in A. tauschii and wheat, and represents a foundation for breeding drought-resistant wheat cultivars using marker-assisted selection. PMID:27560650

  13. Gene Space Dynamics during the Evolution of Aegilops tauschii, Brachypodium distachyon, Oryza sativa, and Sorghum bicolor Genomes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nine different regions totaling 9.7 Mb of the 4.02 Gb Aegilops tauschii genome were sequenced using the Sanger sequencing technology and compared with orthologous Brachypodium distachyon, Oryza sativa (rice) and Sorghum bicolor (sorghum) genomic sequences. The ancestral gene content in these regio...

  14. Stem rust, tan spot, Stagonospora nodorum blotch, and Hessian fly resistance in Langdon durum - Aegilops tauschii synethetic hexaploid wheat lines.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diseases and pests of wheat incur serious yield and quality losses to wheat grown worldwide. In the current study, we tested synthetic hexaploid wheat (SHW) lines developed from various Aegilops tauschii lines crossed with the tetraploid durum wheat line Langdon. The SHW lines were tested along wi...

  15. MlNCD1: A novel Aegilops tauschii derived powdery mildew resistance gene identified in common wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Powdery mildew is a major fungal disease in wheat, especially in cool maritime climates. A novel Aegilops tauschii derived wheat powdery mildew resistance gene present in the germplasm line NC96BGTD1 was genetically characterized as a monogenic trait in field trials using F2 and F4-derived lines fr...

  16. A 4-gigabase physical map unlocks the structure and evolution of the complex genome of Aegilops tauschii, the wheat D-genome progenitor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The current limitations in genome sequencing technology require the construction of physical maps for high-quality draft sequences of large plant genomes, such as that of Aegilops tauschii, the wheat D-genome progenitor. To construct a physical map of the Ae. tauschii genome, we fingerprinted 461,70...

  17. Genome-wide identification of novel genetic markers from RNA sequencing assembly of diverse Aegilops tauschii accessions.

    PubMed

    Nishijima, Ryo; Yoshida, Kentaro; Motoi, Yuka; Sato, Kazuhiro; Takumi, Shigeo

    2016-08-01

    The wild species in the Triticeae tribe are tremendous resources for crop breeding due to their abundant natural variation. However, their huge and highly repetitive genomes have hindered the establishment of physical maps and the completeness of their genome sequences. To develop molecular markers for the efficient utilization of their valuable traits while avoiding their genome complexity, we assembled RNA sequences of ten representative accessions of Aegilops tauschii, the progenitor of the wheat D genome, and estimated single nucleotide polymorphisms (SNPs) and insertions/deletions (indels). The deduced unigenes were anchored to the chromosomes of Ae. tauschii and barley. The SNPs and indels in the anchored unigenes, covering entire chromosomes, were sufficient for linkage map construction, even in combinations between the genetically closest accessions. Interestingly, the resolution of SNP and indel distribution on barley chromosomes was slightly higher than on Ae. tauschii chromosomes. Since barley chromosomes are regarded as virtual chromosomes of Triticeae species, our strategy allows capture of genetic markers arranged on the chromosomes in order based on the conserved synteny. The resolution of these genetic markers will be comparable to that of the Ae. tauschii whose draft genome sequence is available. Our procedure should be applicable to marker development for Triticeae species, which have no draft sequences available. PMID:27142109

  18. Sequencing chromosome 5D of Aegilops tauschii and comparison with its allopolyploid descendant bread wheat (Triticum aestivum).

    PubMed

    Akpinar, Bala A; Lucas, Stuart J; Vrána, Jan; Doležel, Jaroslav; Budak, Hikmet

    2015-08-01

    Flow cytometric sorting of individual chromosomes and chromosome-based sequencing reduces the complexity of large, repetitive Triticeae genomes. We flow-sorted chromosome 5D of Aegilops tauschii, the D genome donor of bread wheat and sequenced it by Roche 454 GS FLX platform to approximately 2.2x coverage. Repetitive sequences represent 81.09% of the survey sequences of this chromosome, and Class I retroelements are the prominent type, with a particular abundance of LTR/Gypsy superfamily. Nonrepetitive sequences were assembled to cover 17.76% of the total chromosome regions. Up to 6188 nonrepetitive gene loci were predicted to be encoded by the 5D chromosome. The numbers and chromosomal distribution patterns of tRNA genes suggest abundance in tRNA(L) (ys) and tRNA(M) (et) species, while the nonrepetitive assembly reveals tRNA(A) (la) species as the most abundant type. A comparative analysis of the genomic sequences of bread wheat and Aegilops chromosome 5D indicates conservation of gene content. Orthologous unique genes, matching Aegilops 5D sequences, numbered 3730 in barley, 5063 in Brachypodium, 4872 in sorghum and 4209 in rice. In this study, we provide a chromosome-specific view into the structure and organization of the 5D chromosome of Ae. tauschii, the D genome ancestor of bread wheat. This study contributes to our understanding of the chromosome-level evolution of the wheat genome and presents a valuable resource in wheat genomics due to the recent hybridization of Ae. tauschii genome with its tetraploid ancestor. PMID:25516153

  19. Simultaneous transfer, introgression and genomic localization of genes for resistance to stem rust race TTKSK Ug99 from Aegilops tauschii to wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat production is currently threatened by widely virulent races of the wheat stem rust fungus, Puccinia graminis f. sp. tritici, that are part of the TTKSK (also known as ‘Ug99’) race group. The diploid D genome donor species Aegilops tauschii (2n=2x=14, DD) is a readily accessible source of resis...

  20. 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...

  1. Chloroplast and nuclear microsatellite analysis of Aegilops cylindrica.

    PubMed

    Gandhi, Harish T; Vales, M Isabel; Watson, Christy J W; Mallory-Smith, Carol A; Mori, Naoki; Rehman, Maqsood; Zemetra, Robert S; Riera-Lizarazu, Oscar

    2005-08-01

    Aegilops cylindrica Host (2n = 4x = 28, genome CCDD) is an allotetraploid formed by hybridization between the diploid species Ae. tauschii Coss. (2n = 2x = 14, genome DD) and Ae. markgrafii (Greuter) Hammer (2n = 2x = 14, genome CC). Previous research has shown that Ae. tauschii contributed its cytoplasm to Ae. cylindrica. However, our analysis with chloroplast microsatellite markers showed that 1 of the 36 Ae. cylindrica accessions studied, TK 116 (PI 486249), had a plastome derived from Ae. markgrafii rather than Ae. tauschii. Thus, Ae. markgrafii has also contributed its cytoplasm to Ae. cylindrica. Our analysis of chloroplast and nuclear microsatellite markers also suggests that D-type plastome and the D genome in Ae. cylindrica were closely related to, and were probably derived from, the tauschii gene pool of Ae. tauschii. A determination of the likely source of the C genome and the C-type plastome in Ae. cylindrica was not possible. PMID:15986256

  2. Reaction of selected accessions of Aegilops tauschii to wheat blast, 2011

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The wheat pathotype of M. oryzae is not known to occur outside of South America. To prepare for possible introduction into the U.S., it is important to search for sources of resistance including resistance in relatives of wheat. Ten accessions of the D genome progenitor of wheat, Ae. tauschii, and t...

  3. A 4-gigabase physical map unlocks the structure and evolution of the complex genome of Aegilops tauschii, the wheat D-genome progenitor

    PubMed Central

    Luo, Ming-Cheng; Gu, Yong Q.; You, Frank M.; Deal, Karin R.; Ma, Yaqin; Hu, Yuqin; Huo, Naxin; Wang, Yi; Wang, Jirui; Chen, Shiyong; Jorgensen, Chad M.; Zhang, Yong; McGuire, Patrick E.; Pasternak, Shiran; Stein, Joshua C.; Ware, Doreen; Kramer, Melissa; McCombie, W. Richard; Kianian, Shahryar F.; Martis, Mihaela M.; Mayer, Klaus F. X.; Sehgal, Sunish K.; Li, Wanlong; Gill, Bikram S.; Bevan, Michael W.; Šimková, Hana; Doležel, Jaroslav; Weining, Song; Lazo, Gerard R.; Anderson, Olin D.; Dvorak, Jan

    2013-01-01

    The current limitations in genome sequencing technology require the construction of physical maps for high-quality draft sequences of large plant genomes, such as that of Aegilops tauschii, the wheat D-genome progenitor. To construct a physical map of the Ae. tauschii genome, we fingerprinted 461,706 bacterial artificial chromosome clones, assembled contigs, designed a 10K Ae. tauschii Infinium SNP array, constructed a 7,185-marker genetic map, and anchored on the map contigs totaling 4.03 Gb. Using whole genome shotgun reads, we extended the SNP marker sequences and found 17,093 genes and gene fragments. We showed that collinearity of the Ae. tauschii genes with Brachypodium distachyon, rice, and sorghum decreased with phylogenetic distance and that structural genome evolution rates have been high across all investigated lineages in subfamily Pooideae, including that of Brachypodieae. We obtained additional information about the evolution of the seven Triticeae chromosomes from 12 ancestral chromosomes and uncovered a pattern of centromere inactivation accompanying nested chromosome insertions in grasses. We showed that the density of noncollinear genes along the Ae. tauschii chromosomes positively correlates with recombination rates, suggested a cause, and showed that new genes, exemplified by disease resistance genes, are preferentially located in high-recombination chromosome regions. PMID:23610408

  4. 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

  5. Simultaneous transfer, introgression, and genomic localization of genes for resistance to stem rust race TTKSK (Ug99) from Aegilops tauschii to wheat.

    PubMed

    Olson, Eric L; Rouse, Matthew N; Pumphrey, Michael O; Bowden, Robert L; Gill, Bikram S; Poland, Jesse A

    2013-05-01

    Wheat production is currently threatened by widely virulent races of the wheat stem rust fungus, Puccinia graminis f. sp. tritici, that are part of the TTKSK (also known as 'Ug99') race group. The diploid D genome donor species Aegilops tauschii (2n = 2x = 14, DD) is a readily accessible source of resistance to TTKSK and its derivatives that can be transferred to hexaploid wheat, Triticum aestivum (2n = 6x = 42, AABBDD). To expedite transfer of TTKSK resistance from Ae. tauschii, a direct hybridization approach was undertaken that integrates gene transfer, mapping, and introgression into one process. Direct crossing of Ae. tauschii accessions with an elite wheat breeding line combines the steps of gene transfer and introgression while development of mapping populations during gene transfer enables the identification of closely linked markers. Direct crosses were made using TTKSK-resistant Ae. tauschii accessions TA1662 and PI 603225 as males and a stem rust-susceptible T. aestivum breeding line, KS05HW14, as a female. Embryo rescue enabled recovery of F1 (ABDD) plants that were backcrossed as females to the hexaploid recurrent parent. Stem rust-resistant BC1F1 plants from each Ae. tauschii donor source were used as males to generate BC2F1 mapping populations. Bulked segregant analysis of BC2F1 genotypes was performed using 70 SSR loci distributed across the D genome. Using this approach, stem rust resistance genes from both accessions were located on chromosome arm 1DS and mapped using SSR and EST-STS markers. An allelism test indicated the stem rust resistance gene transferred from PI 603225 is Sr33. Race specificity suggests the stem rust resistance gene transferred from TA1662 is unique and this gene has been temporarily designated SrTA1662. Stem rust resistance genes derived from TA1662 and PI 603225 have been made available with selectable molecular markers in genetic backgrounds suitable for stem rust resistance breeding. PMID:23377571

  6. Physical mapping resources for large plant genomes: radiation hybrids for wheat D-genome progenitor Aegilops tauschii

    PubMed Central

    2012-01-01

    Background Development of a high quality reference sequence is a daunting task in crops like wheat with large (~17Gb), highly repetitive (>80%) and polyploid genome. To achieve complete sequence assembly of such genomes, development of a high quality physical map is a necessary first step. However, due to the lack of recombination in certain regions of the chromosomes, genetic mapping, which uses recombination frequency to map marker loci, alone is not sufficient to develop high quality marker scaffolds for a sequence ready physical map. Radiation hybrid (RH) mapping, which uses radiation induced chromosomal breaks, has proven to be a successful approach for developing marker scaffolds for sequence assembly in animal systems. Here, the development and characterization of a RH panel for the mapping of D-genome of wheat progenitor Aegilops tauschii is reported. Results Radiation dosages of 350 and 450 Gy were optimized for seed irradiation of a synthetic hexaploid (AABBDD) wheat with the D-genome of Ae. tauschii accession AL8/78. The surviving plants after irradiation were crossed to durum wheat (AABB), to produce pentaploid RH1s (AABBD), which allows the simultaneous mapping of the whole D-genome. A panel of 1,510 RH1 plants was obtained, of which 592 plants were generated from the mature RH1 seeds, and 918 plants were rescued through embryo culture due to poor germination (<3%) of mature RH1 seeds. This panel showed a homogenous marker loss (2.1%) after screening with SSR markers uniformly covering all the D-genome chromosomes. Different marker systems mostly detected different lines with deletions. Using markers covering known distances, the mapping resolution of this RH panel was estimated to be <140kb. Analysis of only 16 RH lines carrying deletions on chromosome 2D resulted in a physical map with cM/cR ratio of 1:5.2 and 15 distinct bins. Additionally, with this small set of lines, almost all the tested ESTs could be mapped. A set of 399 most informative RH

  7. Expansion of the gamma-gliadin gene family in Aegilops and Triticum

    PubMed Central

    2012-01-01

    Background The gamma-gliadins are considered to be the oldest of the gliadin family of storage proteins in Aegilops/Triticum. However, the expansion of this multigene family has not been studied in an evolutionary perspective. Results We have cloned 59 gamma-gliadin genes from Aegilops and Triticum species (Aegilops caudata L., Aegilops comosa Sm. in Sibth. & Sm., Aegilops mutica Boiss., Aegilops speltoides Tausch, Aegilops tauschii Coss., Aegilops umbellulata Zhuk., Aegilops uniaristata Vis., and Triticum monococcum L.) representing eight different genomes: Am, B/S, C, D, M, N, T and U. Overall, 15% of the sequences contained internal stop codons resulting in pseudogenes, but this percentage was variable among genomes, up to over 50% in Ae. umbellulata. The most common length of the deduced protein, including the signal peptide, was 302 amino acids, but the length varied from 215 to 362 amino acids, both obtained from Ae. speltoides. Most genes encoded proteins with eight cysteines. However, all Aegilops species had genes that encoded a gamma-gliadin protein of 302 amino acids with an additional cysteine. These conserved nine-cysteine gamma-gliadins may perform a specific function, possibly as chain terminators in gluten network formation in protein bodies during endosperm development. A phylogenetic analysis of gamma-gliadins derived from Aegilops and Triticum species and the related genera Lophopyrum, Crithopsis, and Dasypyrum showed six groups of genes. Most Aegilops species contained gamma-gliadin genes from several of these groups, which also included sequences from the genera Lophopyrum, Crithopsis, and Dasypyrum. Hordein and secalin sequences formed separate groups. Conclusions We present a model for the evolution of the gamma-gliadins from which we deduce that the most recent common ancestor (MRCA) of Aegilops/Triticum-Dasypyrum-Lophopyrum-Crithopsis already had four groups of gamma-gliadin sequences, presumably the result of two rounds of duplication of

  8. Molecular survey of Tamyb10-1 genes and their association with grain colour and germinability in Chinese wheat and Aegilops tauschii.

    PubMed

    Dong, Zhong Dong; Chen, Jie; Li, Ting; Chen, Feng; Cui, Dang Qun

    2015-09-01

    To investigate allelic variation of Myb10-1 genes in Chinese wheat and to examine its association with germination level in wheat, a total of 582 Chinese bread wheat cultivars and 110 Aegilops tauschii accessions were used to identify allelic variations of three Myb10-1 genes. Identification results indicated that there is a novel Tamyb10-B1 allele, designated Tamyb10-B1c, in the five Chinese landraces. The Tamyb10-B1c possibly has a large deletion including Tamyb10-B1 gene. There are three novel Tamyb10-D1 alleles (Aetmyb10-D1c, Aetmyb10-D1d and Aetmyb10-D1e) that were discovered in Aegilops tauschii. Of them, Aetmyb10-D1c allele possessed a 104-bp deletion and this resulted in a frame shift in the open reading frame of the Aetmyb10-D1 gene. AETMYB10-D1d and AETMYB10-D1e proteins possessed three and two different amino acids when compared with TAMYB10-D1b protein, respectively. Association of Tamyb10-1 allelic variation with grain germination level indicated that all five allelic combinations with red grains showed a significantly higher GP (germination percentage) and GI (germination index) values than those of white-grained Tamyb10-A1a/Tamyb10-B1a/Tamyb10-D1a genotype after storing it for one year. Moreover, the Tamyb10-A1b/Tamyb10-B1c/Tamyb10-D1b genotype possesses the significantly highest GP and GI among the six different Tamyb10-1 combinations. This study could provide useful information for wheat breeding programme in terms of grain colour and germination level. PMID:26440084

  9. Identification of CBF14 and NAC2 Genes in Aegilops tauschii Associated with Resistance to Freezing Stress.

    PubMed

    Masoomi-Aladizgeh, Farhad; Aalami, Ali; Esfahani, Masoud; Aghaei, Mohamad Jaafar; Mozaffari, Khadijeh

    2015-06-01

    Low temperature as one of the most important environmental factors limits the productivity of plants across the world. Aegilops, as a wild species of Poaceae, contains low temperature-responsive genes. In this study, we analyzed morphological (wilting, chlorosis, and recovery) and physiological (ion leakage) characteristics to identification of a cold-tolerant genotype. In this experiment, we introduced two transcription factors (TFs) in Aegilops species for the first time. Bioinformatics analysis demonstrated that our nucleotide sequences have high similarity with CBF14 (C-repeat-binding factor) and NAC2 (NAM, ATAF, and CUC) in Triticum aestivum. Based on the physiological and morphological data, one genotype (Aladizgeh) was identified as the most resistant genotype which was selected for further gene expression analysis. The real-time PCR results indicated that the CBF14 gene was not expressed 3 h following cold treatment, but the highest expression was observed after 6, 12, and 24 h of cold treatment; however, a sudden decrease was observed in its expression after 30 h. The NAC2 gene also was not expressed 3 h after cold stress, but the highest expression was at 24 h and similar to the CBF14 gene; its expression suddenly decreased after 30 h. Our results indicated that this genotype can tolerate -4 °C for 3 h, but the CBF14 and NAC2 genes were activated when treated for longer durations. Expression of TFs studied in this experiment had decreased after 30 h, in which cell death seems to be the important reason. PMID:25900437

  10. Accelerated senescence and enhanced disease resistance in hybrid chlorosis lines derived from interspecific crosses between tetraploid wheat and Aegilops tauschii.

    PubMed

    Nakano, Hiroki; Mizuno, Nobuyuki; 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. 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

  12. Harnessing NGS and Big Data Optimally: Comparison of miRNA Prediction from Assembled versus Non-assembled Sequencing Data--The Case of the Grass Aegilops tauschii Complex Genome.

    PubMed

    Budak, Hikmet; Kantar, Melda

    2015-07-01

    MicroRNAs (miRNAs) are small, endogenous, non-coding RNA molecules that regulate gene expression at the post-transcriptional level. As high-throughput next generation sequencing (NGS) and Big Data rapidly accumulate for various species, efforts for in silico identification of miRNAs intensify. Surprisingly, the effect of the input genomics sequence on the robustness of miRNA prediction was not evaluated in detail to date. In the present study, we performed a homology-based miRNA and isomiRNA prediction of the 5D chromosome of bread wheat progenitor, Aegilops tauschii, using two distinct sequence data sets as input: (1) raw sequence reads obtained from 454-GS FLX Titanium sequencing platform and (2) an assembly constructed from these reads. We also compared this method with a number of available plant sequence datasets. We report here the identification of 62 and 22 miRNAs from raw reads and the assembly, respectively, of which 16 were predicted with high confidence from both datasets. While raw reads promoted sensitivity with the high number of miRNAs predicted, 55% (12 out of 22) of the assembly-based predictions were supported by previous observations, bringing specificity forward compared to the read-based predictions, of which only 37% were supported. Importantly, raw reads could identify several repeat-related miRNAs that could not be detected with the assembly. However, raw reads could not capture 6 miRNAs, for which the stem-loops could only be covered by the relatively longer sequences from the assembly. In summary, the comparison of miRNA datasets obtained by these two strategies revealed that utilization of raw reads, as well as assemblies for in silico prediction, have distinct advantages and disadvantages. Consideration of these important nuances can benefit future miRNA identification efforts in the current age of NGS and Big Data driven life sciences innovation. PMID:26061358

  13. Recent emergence of the wheat Lr34 multi-pathogen resistance: insights from haplotype analysis in wheat, rice, sorghum and Aegilops tauschii.

    PubMed

    Krattinger, Simon G; Jordan, David R; Mace, Emma S; Raghavan, Chitra; Luo, Ming-Cheng; Keller, Beat; Lagudah, Evans S

    2013-03-01

    Spontaneous sequence changes and the selection of beneficial mutations are driving forces of gene diversification and key factors of evolution. In highly dynamic co-evolutionary processes such as plant-pathogen interactions, the plant's ability to rapidly adapt to newly emerging pathogens is paramount. The hexaploid wheat gene Lr34, which encodes an ATP-binding cassette (ABC) transporter, confers durable field resistance against four fungal diseases. Despite its extensive use in breeding and agriculture, no increase in virulence towards Lr34 has been described over the last century. The wheat genepool contains two predominant Lr34 alleles of which only one confers disease resistance. The two alleles, located on chromosome 7DS, differ by only two exon-polymorphisms. Putatively functional homoeologs and orthologs of Lr34 are found on the B-genome of wheat and in rice and sorghum, but not in maize, barley and Brachypodium. In this study we present a detailed haplotype analysis of homoeologous and orthologous Lr34 genes in genetically and geographically diverse selections of wheat, rice and sorghum accessions. We found that the resistant Lr34 haplotype is unique to the wheat D-genome and is not found in the B-genome of wheat or in rice and sorghum. Furthermore, we only found the susceptible Lr34 allele in a set of 252 Ae. tauschii genotypes, the progenitor of the wheat D-genome. These data provide compelling evidence that the Lr34 multi-pathogen resistance is the result of recent gene diversification occurring after the formation of hexaploid wheat about 8,000 years ago. PMID:23117720

  14. Genetic structure of Aegilops cylindrica Host in its native range and in the United States of America.

    PubMed

    Gandhi, Harish T; Vales, M Isabel; Mallory-Smith, Carol; Riera-Lizarazu, Oscar

    2009-10-01

    Chloroplast and nuclear microsatellite markers were used to study genetic diversity and genetic structure of Aegilops cylindrica Host collected in its native range and in adventive sites in the USA. Our analysis suggests that Ae. cylindrica, an allotetraploid, arose from multiple hybridizations between Ae. markgrafii (Greuter) Hammer. and Ae. tauschii Coss. presumably along the Fertile Crescent, where the geographic distributions of its diploid progenitors overlap. However, the center of genetic diversity of this species now encompasses a larger area including northern Iraq, eastern Turkey, and Transcaucasia. Although the majority of accessions of Ae. cylindrica (87%) had D-type plastomes derived from Ae. tauschii, accessions with C-type plastomes (13%), derived from Ae. markgrafii, were also observed. This corroborates a previous study suggesting the dimaternal origin of Ae. cylindrica. Model-based and genetic distance-based clustering using both chloroplast and nuclear markers indicated that Ae. tauschii ssp. tauschii contributed one of its D-type plastomes and its D genome to Ae. cylindrica. Analysis of genetic structure using nuclear markers suggested that Ae. cylindrica accessions could be grouped into three subpopulations (arbitrarily named N-K1, N-K2, and N-K3). Members of the N-K1 subpopulation were the most numerous in its native range and members of the N-K2 subpopulation were the most common in the USA. Our analysis also indicated that Ae. cylindrica accessions in the USA were derived from a few founder genotypes. The frequency of Ae. cylindrica accessions with the C-type plastome in the USA (approximately 24%) was substantially higher than in its native range of distribution (approximately 3%) and all C-type Ae. cylindrica in the USA except one belonged to subpopulation N-K2. The high frequency of the C-type plastome in the USA may reflect a favorable nucleo-cytoplasmic combination. PMID:19618161

  15. Introgression of wheat DNA markers from A, B and D genomes in early generation progeny of Aegilops cylindrica Host x Triticum aestivum L. hybrids.

    PubMed

    Schoenenberger, N; Felber, F; Savova-Bianchi, D; Guadagnuolo, R

    2005-11-01

    Introgression from allohexaploid wheat (Triticum aestivum L., AABBDD) to allotetraploid jointed goatgrass (Aegilops cylindrica Host, CCDD) can take place in areas where the two species grow in sympatry and hybridize. Wheat and Ae. cylindrica share the D genome, issued from the common diploid ancestor Aegilops tauschii Coss. It has been proposed that the A and B genome of bread wheat are secure places to insert transgenes to avoid their introgression into Ae. cylindrica because during meiosis in pentaploid hybrids, A and B genome chromosomes form univalents and tend to be eliminated whereas recombination takes place only in D genome chromosomes. Wheat random amplified polymorphic DNA (RAPD) fragments, detected in intergeneric hybrids and introgressed to the first backcross generation with Ae. cylindrica as the recurrent parent and having a euploid Ae. cylindrica chromosome number or one supernumerary chromosome, were assigned to wheat chromosomes using Chinese Spring nulli-tetrasomic wheat lines. Introgressed fragments were not limited to the D genome of wheat, but specific fragments of A and B genomes were also present in the BC1. Their presence indicates that DNA from any of the wheat genomes can introgress into Ae. cylindrica. Successfully located RAPD fragments were then converted into highly specific and easy-to-use sequence characterised amplified regions (SCARs) through sequencing and primer design. Subsequently these markers were used to characterise introgression of wheat DNA into a BC1S1 family. Implications for risk assessment of genetically modified wheat are discussed. PMID:16133306

  16. COSS Lesson Creation Process

    NASA Technical Reports Server (NTRS)

    Harper, R. Stephen

    1999-01-01

    COSS (Crew On-Orbit System Support) is changing. Designed as computer based in-flight refresher training, it is getting good reviews and the demands on the product can be expected to increase. Last year, the lessons were written using Authorware, which had a number of limitations. The most important one was that the navigation and the layout functions were both in one package that was not easy to learn. The lesson creator had to be good at both programming and design. There were also a number of other problems, as detailed in my report last year. This year the COSS unit made the switch to embrace modularity. The navigation function is handled by a player that was custom-written using Delphi. The layout pages are now standard HTML files that can be created using any number of products. This new system gives new flexibility and unties the process from one product (and one company). The player can be re-written by a programmer without affecting the lesson pages. It is also now possible for anybody with a word-processor to make part of the HTML lesson pages and to use many of the new commercially available tools that are being designed for web pages. This summer I created a computer-based training (CBT) lesson on the IBM ThinkPad 760 ED and 760XD laptop computers that should fly on the International Space Station. I also examined the COSS system, the new player and the other new software products.

  17. [Phylogenetic relationships and intraspecific variation of D-genome Aegilops L. as revealed by RAPD analysis].

    PubMed

    Goriunova, S V; Kochieva, E Z; Chikida, N N; Pukhal'skiĭ, V A

    2004-05-01

    RAPD analysis was carried out to study the genetic variation and phylogenetic relationships of polyploid Aegilops species, which contain the D genome as a component of the alloploid genome, and diploid Aegilops tauschii, which is a putative donor of the D genome for common wheat. In total, 74 accessions of six D-genome Aegilops species were examined. The highest intraspecific variation (0.03-0.21) was observed for Ae. tauschii. Intraspecific distances between accessions ranged 0.007-0.067 in Ae. cylindrica, 0.017-0.047 in Ae. vavilovii, and 0.00-0.053 in Ae. juvenalis. Likewise, Ae. ventricosa and Ae. crassa showed low intraspecific polymorphism. The among-accession difference in alloploid Ae. ventricosa (genome DvNv) was similar to that of one parental species, Ae. uniaristata (N), and substantially lower than in the other parent, Ae. tauschii (D). The among-accession difference in Ae. cylindrica (CcDc) was considerably lower than in either parent, Ae. tauschii (D) or Ae. caudata (C). With the exception of Ae. cylindrica, all D-genome species--Ae. tauschii (D), Ae. ventricosa (DvNv), Ae. crassa (XcrDcrl and XcrDcrlDcr2), Ae. juvenalis (XjDjUj), and Ae. vavilovii (XvaDvaSva)--formed a single polymorphic cluster, which was distinct from clusters of other species. The only exception, Ae. cylindrica, did not group with the other D-genome species, but clustered with Ae. caudata (C), a donor of the C genome. The cluster of these two species was clearly distinct from the cluster of the other D-genome species and close to a cluster of Ae. umbellulata (genome U) and Ae. ovata (genome UgMg). Thus, RAPD analysis for the first time was used to estimate and to compare the interpopulation polymorphism and to establish the phylogenetic relationships of all diploid and alloploid D-genome Aegilops species. PMID:15272562

  18. Characterization of high molecular weight glutenin subunits in Thinopyrum intermedium, Th. bessarabicum, Lophopyrum elongatum, Aegilops markgrafii, and their addition lines in wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High molecular weight (HMW) glutenin subunits (GSs) play an important role in determining dough viscoelastic properties and end-use quality in cultivated wheat, and they are also excellent protein markers for genotype identification. The HMW-GSs in wheat species (Triticum ssp.) and Aegilops tauschii...

  19. [SSR mapping of stripe rust resistance gene from Ae. tauschii].

    PubMed

    Zhang, Hai-Quan; Jia, Ji-Zeng; Yang, Hong; Zhang, Bao-Shi

    2008-04-01

    A dominant wheat stripe rust resistance gene, temporarily designated as YrY201, was identified in an accession Y201 of Aegilops tauschii. By bulk segregation analysis, three microsatellite markers Xgwm273b, Xgwm37 and Wmc14 were found to be linked to YrY201 with genetic distance of 11.5, 5.8 and 10.9 cM , respectively. According to the locations of the linked markers, the resistance gene was located on chromosome 7DL. Based on the chromosomal location and the resistance pattern of the gene, we proposed that YrY201 was a novel stripe rust resistance gene, and could be selected by marker-assisted selection. PMID:18424421

  20. [Analysis of 5S rDNA changes in synthetic allopolyploids Triticum x Aegilops].

    PubMed

    Shcherban', A B; Sergeeva, E M; Badaeva, E D; Salina, E A

    2008-01-01

    By the example of three synthetic allopolyploids: Aegilops sharonensis x Ae. umbellulata (2n =28), Triticum urartu x Ae. tauschii (2n =28), T. dicoccoides x Ae. tauschii (2n =42) the 5S rDNA changes at the early stage of allopolyploidization were investigated. Using fluorescent in situ hybridization (FISH), the quantitative changes affecting the separate loci of one of the parental genomes were revealed in plants of S3 generation of each hybrid combination. Souther hybridization with genomic DNA of allopolyploid T. urartu x Ae. tauschii (TMU38 x TQ27) revealed lower intensity of the fragments from Ae. tauschii compared with the T. urartu fragments. It may be confirmation of the reduction of signal on 1D chromosome that was revealed in this hybrid using FISH. Both appearance of a new 5S rDNA fragments and full disappearance of fragments from parental species were not showed by Southern hybridization, as well as PCR-analysis of 5-15 plants of S2-S3 generations. The changes were not found under comparison of primary structure of nine 5S rDNA sequences of allopolyploid TMU38 x TQ27 with analogous sequences from parental species genomes. The observable similarity by FISH results of one of the studied synthetic allopolyploids with natural allopolyploid of similar genome composition indicates the early formation of unique for each allopolyploid 5S rDNA organization. PMID:18856060

  1. Genes encoding plastid acetyl-CoA carboxylase and 3-phosphoglycerate kinase of the Triticum/Aegilops complex and the evolutionary history of polyploid wheat.

    PubMed

    Huang, Shaoxing; Sirikhachornkit, Anchalee; Su, Xiujuan; Faris, Justin; Gill, Bikram; Haselkorn, Robert; Gornicki, Piotr

    2002-06-11

    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 (Triticum turgidum AABB, and Triticum timopheevii AAGG) and hexaploid (Triticum aestivum, AABBDD) species. We analyzed Acc-1 (plastid acetyl-CoA carboxylase) and Pgk-1 (plastid 3-phosphoglycerate kinase) genes to determine phylogenetic relationships among Triticum and Aegilops species of the wheat lineage and to establish the timeline of wheat evolution based on gene sequence comparisons. Triticum urartu was confirmed as the A genome donor of tetraploid and hexaploid wheat. The A genome of polyploid wheat diverged from T. urartu less than half a million years ago (MYA), indicating a relatively recent origin of polyploid wheat. The D genome sequences of T. aestivum and Aegilops tauschii are identical, confirming that T. aestivum arose from hybridization of T. turgidum and Ae. tauschii only 8,000 years ago. The diploid Triticum and Aegilops progenitors of the A, B, D, G, and S genomes all radiated 2.5-4.5 MYA. Our data suggest that the Acc-1 and Pgk-1 loci have different histories in different lineages, indicating genome mosaicity and significant intraspecific differentiation. Some loci of the S genome of Aegilops speltoides and the G genome of T. timophevii are closely related, suggesting the same origin of some parts of their genomes. None of the Aegilops genomes analyzed is a close relative of the B genome, so the diploid progenitor of the B genome remains unknown. PMID:12060759

  2. [Genetics determination of wheat resistance to Puccinia graminis F. sp. tritici deriving from Aegilops cylindrica, Triticum erebuni and amphidiploid 4].

    PubMed

    Babaiants, O V; Babaiants, L T; Horash, A F; Vasil'ev, A A; Trackovetskaia, V A; Paliasn'iĭĭ, V A

    2012-01-01

    The lines of winter soft wheat developed in the Plant Breeding and Genetics Institute contain new effective introgressive Sr-genes. Line 85/06 possess SrAc1 gene, lines 47/06, 54/06, 82/06, 85/06, 87/06, 238/06, and 367/06 possess SrAc1 and SrAc2 derived from Aegilops cylindrica, line 352/06 - SrTe1 and SrTe2 from Triticum erebuni, line 12/86-04 - SrAd1 and SrAd2 from Amphidiploid 4 (Triticum dicoccoides x Triticum tauschii). PMID:22420215

  3. 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...

  4. 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 ...

  5. 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...

  6. Molecular Mapping of Wheat Leaf Rust Resistance Gene Lr42

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaf rust, caused by Puccinia triticina Eriks., is an important foliar disease of wheat (Triticum aestivum L.) worldwide. Leaf rust resistance gene Lr42 from Aegilops tauschii Coss. has been used as a source of rust resistance in breeding programs. To identify molecular markers closely linked to Lr4...

  7. Adult plant resistance to Puccinia triticina in a geographically diverse collection of Aegilops tauschii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite extensive genetics and breeding research, effective control of leaf rust caused by Puccinia triticina Eriks., an important foliar disease of wheat, has not been achieved. This is mainly due to the widespread use of race-specific seedling resistance genes, which are rapidly overcome by new vi...

  8. Mapping Septoria Leaf Blotch and Soil-borne Mosaic Virus Resistance Genes Derived from Aegilops tauschii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Septoria leaf blotch (STB) is a fungal disease of wheat caused by Septoria tritici and is routinely a problem in temperate wheat growing regions. Soil-borne Wheat Mosaic Virus (SBWMV) is a destructive pathogen of wheat that can cause entire crop failure in localized fields. A linkage analysis of a...

  9. Fine genetic mapping of greenbug aphid resistance gene Gb3 in Aegilops tauschii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The greenbug is a serious aphid pest of wheat and sorghum in the southern High Plains of the US. The greenbug resistant gene Gb3 originated from the goatgrass has shown consistent and durable resistance against prevailing greenbug biotypes in wheat fields for moer than 30 years. Our goal is to clone...

  10. Genetic Analysis of Resistance to Soil-borne Wheat Mosiac Virus Derived from Aegilops tauschii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil-borne Wheat Mosaic Virus (SBWMV), vectored by the soil inhabiting fungus Polymyxa graminis, causes damage to wheat (Triticum aestivum) yields in most of the wheat growing regions of the world. In localized fields, the entire crop may be lost to the virus. Although many winter wheat cultivars ...

  11. Fine Mapping of Hessian Fly Resistance Gene H26 in an Aegilops tauschii Population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hessian fly [Mayetiola destructor (Say)] is one of the most important insect pests in wheat (Triticum L.) around the world. Among the 32 genes known to confer wheat resistance to Hessian fly, the H26 is important because it is effective against several highly virulent Hessian fly populations. The H...

  12. Quantification and organization of WIS2-1A and BARE-1 retrotransposons in different genomes of Triticum and Aegilops species.

    PubMed

    Pagnotta, Mario Augusto; Mondini, Linda; Porceddu, Enrico

    2009-09-01

    A real-time PCR approach was adopted and optimized to estimate and compare, through a relative quantification, the copy number of WIS2-1A and BARE-1 retrotransposons. The aim of this approach was to identify and quantify the presence of these retrotransposons in Triticum and Aegilops species, and to understand better the genome organization of these retroelements. The species were selected to assess and compare the evolution of the different types of genomes between the more recent species such as the diploid Triticum monococcum, tetraploid T. dicoccon and hexaploid T. spelta, and the corresponding genome donors of the ancient diploids Aegilops (Ae. speltoides, Ae. tauschii, Ae. sharonensis and Ae. bicornis) and T. urartu. The results of this study indicated the presence of great variation in copy number both within and among species, and the existence of a non-linear relationship between retrotransposon copy number and ploidy level. For WIS2-1A, as expected, T. monococcum showed the lowest copy number which instead was similar in T. dicoccon and T. spelta; also T. urartu (AA), Ae. speltoides (BB) and Ae. tauschii (DD) showed a higher WIS2-1A copy number. Similar results were observed for BARE-1 retroelements except for Ae. tauschii which as in T. monococcum showed lower retroelements content; a similar content for T. dicoccon and T. urartu, whereas a higher number was found in T. spelta and Ae. speltoides. The results presented here are in accord with previous studies and contribute to unravelling the structure and evolution of polyploidy and repetitive genomes. PMID:19543749

  13. Evaluation and characterization of high-molecular weight 1D glutenin subunits from Aegilops tauschii in synthetic hexaploid wheats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The high-molecular weight (HMW) glutenin subunits of bread wheat (Triticum aestivum L.) are major determinants of end-use quality. The objective of this study was to determine the 1Dx and 1Dy HMW subunits present in 44 synthetic hexaploid wheats (SHW) derived by crossing Langdon durum (T. turgidum ...

  14. Screening The Aegilops-Triticum Group For Boron Tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Boron deficient and toxic soils pose a critical problem in wheat production on a world scale. Therefore, 79 accessions from 12 diverse wild wheat (Aegilops speltoides, Ae. longissima, Ae. sharonensis, Ae. bicornis, Ae. searsii, Ae. kotschyi, Ae. peregrina ssp. cylindrostachys, Ae. peregrina ssp. eu...

  15. Chromosomal location of Pm35, a novel Aegilops tauschii derived powdery mildew resistance gene introgressed into common wheat (Triticum aestivum L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A single gene controlling powdery mildew resistance was identified in the North Carolina germplasm line NC96BGTD3 (NCD3) using genetic analysis of F2 derived lines from a NCD3 X Saluda cross. Microsatellite markers linked to this Pm gene were identified and their most likely order was Xcfd7, 10.3cM,...

  16. Physical mapping resources for large plant genomes: radiation hybrids for wheat D-genome progenitor aegilops tauschii accession AL8/78

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: A high quality reference sequence can provide a complete catalog of genes of a species, the regulatory elements that control their structure and function provide the basis for understanding the role of genes in evolution and development. However, development of a high quality referenc...

  17. Radiation hybrid maps of D-genome of Aegilops tauschii and their application in sequence assembly of large and complex plant genomes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The large and complex genome of bread wheat (Triticum aestivum L., ~17 Gb) requires high-resolution genome maps saturated with ordered markers to assist in anchoring and orienting BAC contigs/ sequence scaffolds for whole genome sequence assembly. Radiation hybrid (RH) mapping has proven to be an e...

  18. A 4-gigbase physical map unlocks the structure and evolution of the complex genome of Aegilop tauschii, the wheat D-genome progenitor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genomes of wheat and its relatives in the tribe Triticeae are large, containing nearly 90% repetitive DNA, and some are polyploid. These genomes can currently be completely sequenced only by the ordered-clone genome sequencing approach, which reduces the complexity of sequence assembly from th...

  19. Dynamic evolution of resistance gene analogs in the orthologous genomic regions of powdery mildew resistance gene MlIW170 in Triticum dicoccoides and Aegilops tauschii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat is one of the most important staple grain crops in the world. Powdery mildew disease caused by Blumeria graminis f.sp. tritici can result in significant losses in both grain yield and quality in wheat. In this study, the wheat powdery mildew resistance gene MlIW170 locus located on the short ...

  20. Annotation-based genome-wide SNP discovery in the large and complex Aegilops tauschii genome using next-generation sequencing without a reference genome sequence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An annotation-based, genome-wide SNP discovery pipeline is reported using NGS data for large and complex genomes without a reference genome sequence. Roche 454 shotgun reads with low genome coverage of one genotype are annotated in order to distinguish single-copy sequences and repeat junctions fr...

  1. Identification of transposons, retroelements, and a gene family predominantly expressed in floral tissues in chromosome 3DS of the hexaploid wheat progenitor Aegilops tauschii.

    PubMed

    Whitford, Ryan; Baumann, Ute; Sutton, Tim; Gumaelius, Luke; Wolters, Petra; Tingey, Scott; Able, Jason A; Langridge, Peter

    2007-01-01

    A multigene family expressed during early floral development was identified on the short arm of wheat chromosome 3D in the region of the Ph2 locus, a locus controlling homoeologous chromosome pairing in allohexaploid wheat. Physical, genetic and molecular characterisation of the Wheat Meiosis 1 (WM1) gene family identified seven members that localised within a region of 173-kb. WM1 gene family members were sequenced and they encode mainly type Ia plasma membrane-anchored leucine rich repeat-like receptor proteins. In situ expression profiling suggests the gene family is predominantly expressed in floral tissue. In addition to the WM1 gene family, a number of other genes, gene fragments and pseudogenes were identified. It has been predicted that there is approximately one gene every 19-kb and that this region of the wheat genome contains 23 repetitive elements including BARE-1 and Wis2-1 like sequences. Nearly 50% of the repetitive elements identified were similar to known transposons from the CACTA superfamily. Ty1-copia, Ty3-gypsy and Athila LTR retroelements were also prevalent within the region. The WM1 gene cluster is present on 3DS and on barley 3HS but missing from the A and B genomes of hexaploid wheat. This suggests either recent generation of the cluster or specific deletion of the cluster during wheat polyploidisation. The evolutionary significance of the cluster, its possible roles in disease response or floral and early meiotic development and its location at or near the Ph2 locus are discussed. PMID:16534632

  2. Rapid genome mapping in nano channel array for highly complete and accurate de novo sequence assembly of the complex Aegilops tauschii genome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Next-generation sequencing (NGS) technologies have enabled high-throughput and low-cost generation of sequence data; however, de novo genome assembly remains a great challenge, particularly for large genomes. NGS short reads are often insufficient to create large contigs that span repeat sequences...

  3. Identification and mapping of Sr46 from Aegilops tauschii accession CIae 25 conferring resistance to race TTKSK (Ug99) of wheat stem rust pathogen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The race TTKSK (Ug99) of Puccinia graminis f. sp. tritici, the casual pathogen for wheat stem rust, is currently a major threat to global wheat production. To confine this threat, researchers across the world have been devoted to identifying TTKSK-resistant genes. Here, we report the identificatio...

  4. Rapid evolutionary dynamics in a 2.8-Mb chromosomal region containing multiple prolamin and resistance gene families in Aegilops tauschii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prolamin (seed storage proteins high in glutamine and proline) and resistance gene families are important in domesticated bread wheat (Triticum aestivum) food uses and in defense against pathogen attacks, respectively. To better understand the evolution of these multi-gene families, the DNA se...

  5. Genome structure of introgressive lines Triticum aestivum/Aegilops sharonensis.

    PubMed

    Antonyuk, M Z; Bodylyova, M V; Ternovskaya, T K

    2009-01-01

    The lines Triticum aestivum/Aegilops sharonensis were explored in regard to the presence of introgressions in the line genomes, their amount and belonging to definite homoeologic group. The results of studying of chromosome associations in M1 of pollen mother celles in the hybrids between the lines with each other and with recurrent common wheat genotype Avrora were compared with the data of the line assessment for the chromosomal biochemical and morphological markers. 26 lines were distinguished between six groups with specific genome rearrangement regard to recurrent genotype. PMID:20458978

  6. The Effectiveness of an Intervention to Enhance Cooperation Between Sick-Listed Employees and Their Supervisors (COSS).

    PubMed

    Hoefsmit, Nicole; Houkes, Inge; Boumans, Nicolle; Noben, Cindy; Winkens, Bjorn; Nijhuis, Frans J N

    2016-06-01

    Introduction Early return-to-work (RTW) after sick leave is considered to support employees' quality of life. Successful RTW requires adequate cooperation between absent employees and their supervisors. This study assesses the effectiveness of an intervention for COoperation regarding RTW between Sick-listed employees and their Supervisors (COSS; i.e. 'conversation roadmap', monitoring of cooperation and, if necessary, extra occupational physician support). Methods In this field study, employees on sick leave for 2-10 weeks, aged 18 up to and including 60, and performing paid labour for at least 12 h per week were included. Terminally ill were excluded. Multivariate regression (correcting for baseline quality of life) was used to compare 6-months follow up data regarding quality of life between the groups. Using Cox regression analyses, time until first-, full-, and sustainable RTW was compared between groups. Results In total 64 employees received COSS or common practice. No significant group differences were found regarding all study outcomes. The COSS group had a higher chance of work resumption than the common practice group. The hazard ratio was 1.39 for first RTW (95 % CI 0.81-2.37), 1.12 for full RTW (95 % CI 0.65-1.93) and 1.10 for sustainable RTW (95 % CI 0.63-1.95). Conclusions COSS has no significant effects. Yet, the results regarding work resumption show a tendency towards effectiveness. Therefore, COSS can be further developed and applied in practice. Researchers should try to prevent some limitations of the present study in future research, for instance by finding a more common research setting. PMID:26386993

  7. Lr41, Lr39, and a leaf rust resistance gene from Aegilops cylindrica may be allelic and are located on wheat chromosome 2DS.

    PubMed

    Singh, Sukhwinder; Franks, C D; Huang, L; Brown-Guedira, G L; Marshall, D S; Gill, B S; Fritz, A

    2004-02-01

    The leaf rust resistance gene Lr41 in wheat germplasm KS90WGRC10 and a resistance gene in wheat breeding line WX93D246-R-1 were transferred to Triticum aestivum from Aegilops tauschii and Ae. cylindrica, respectively. The leaf rust resistance gene in WX93D246-R-1 was located on wheat chromosome 2D by monosomic analysis. Molecular marker analysis of F(2) plants from non-critical crosses determined that this gene is 11.2 cM distal to marker Xgwm210 on the short arm of 2D. No susceptible plants were detected in a population of 300 F(2) plants from a cross between WX93D246-R-1 and TA 4186 ( Lr39), suggesting that the gene in WX93D246-R-1 is the same as, or closely linked to, Lr39. In addition, no susceptible plants were detected in a population of 180 F(2) plants from the cross between KS90WGRC10 and WX93D246-R-1. The resistance gene in KS90WGRC10, Lr41, was previously reported to be located on wheat chromosome 1D. In this study, no genetic association was found between Lr41 and 51 markers located on chromosome 1D. A population of 110 F(3 )lines from a cross between KS90WGRC10 and TAM 107 was evaluated with polymorphic SSR markers from chromosome 2D and marker Xgdm35 was found to be 1.9 cM proximal to Lr41. When evaluated with diverse isolates of Puccinia triticina, similar reactions were observed on WX93D246-R-1, KS90WGRC10, and TA 4186. The results of mapping, allelism, and race specificity test indicate that these germplasms likely have the same gene for resistance to leaf rust. PMID:14534751

  8. Cytogenetic analysis of Aegilops chromosomes, potentially usable in triticale (X Triticosecale Witt.) breeding.

    PubMed

    Kwiatek, M; Wiśniewska, H; Apolinarska, B

    2013-05-01

    Chromosome identification using fluorescence in situ hybridization (FISH) is widely used in cytogenetic research. It is a diagnostic tool helpful in chromosome identification. It can also be used to characterize alien introgressions, when exercised in a combination with genomic in situ hybridization (GISH). This work aims to find chromosome identification of Aegilops species and Aegilops × Secale amphiploids, which can be used in cereal breeding as a source of favourable agronomic traits. Four diploid and two tetraploid Aegilops species and three Aegilops × Secale hybrids were analysed using FISH with pSc119.2, pAs1, 5S rDNA and 25S rDNA clones to differentiate the U-, M-, S(sh)- and D-subgenome chromosomes of Aegilops genus. Additionally, GISH for chromosome categorization was carried out. Differences in the hybridization patterns allowed to identify all U-, M-, S(sh)- and D-subgenome chromosomes. Some differences in localization of the rDNA, pSc119.2 and pAs1 sequences between analogue subgenomes in diploid and tetraploid species and Aegilops × Secale hybrids were detected. The hybridization pattern of the M and S genome was more variable than that of the U and D genome. An importance of the cytogenetic markers in plant breeding and their possible role in chromosome structure, function and evolution is discussed. PMID:23378244

  9. Allelic variations of α-gliadin genes from species of Aegilops section Sitopsis and insights into evolution of α-gliadin multigene family among Triticum and Aegilops.

    PubMed

    Huang, Zhuo; Long, Hai; Wei, Yu-Ming; Yan, Ze-Hong; Zheng, You-Liang

    2016-04-01

    The α-gliadins account for 15-30 % of the total storage protein in wheat endosperm and play important roles in the dough extensibility and nutritional quality. On the other side, they act as a main source of toxic peptides triggering celiac disease. In this study, 37 α-gliadins were isolated from three species of Aegilops section Sitopsis. Sequence similarity and phylogenetic analyses revealed novel allelic variation at Gli-2 loci of species of Sitopsis and regular organization of motifs in their repetitive domain. Based on the comprehensive analyses of a large number of known sequences of bread wheat and its diploid genome progenitors, the distributions of four T cell epitopes and length variations of two polyglutamine domains are analyzed. Additionally, according to the organization of repeat motifs, we classified the α-gliadins of Triticum and Aegilops into eight types. Their most recent common ancestor and putative divergence patterns were further considered. This study provides new insights into the allelic variations of α-gliadins in Aegilops section Sitopsis, as well as evolution of α-gliadin multigene family among Triticum and Aegilops species. PMID:26940567

  10. Gene flow between wheat and wild relatives: empirical evidence from Aegilops geniculata, Ae. neglecta and Ae. triuncialis

    PubMed Central

    Arrigo, Nils; Guadagnuolo, Roberto; Lappe, Sylvain; Pasche, Sophie; Parisod, Christian; Felber, François

    2011-01-01

    Gene flow between domesticated species and their wild relatives is receiving growing attention. This study addressed introgression between wheat and natural populations of its wild relatives (Aegilops species). The sampling included 472 individuals, collected from 32 Mediterranean populations of three widespread Aegilops species (Aegilops geniculata, Ae. neglecta and Ae. triuncialis) and compared wheat field borders to areas isolated from agriculture. Individuals were characterized with amplified fragment length polymorphism fingerprinting, analysed through two computational approaches (i.e. Bayesian estimations of admixture and fuzzy clustering), and sequences marking wheat-specific insertions of transposable elements. With this combined approach, we detected substantial gene flow between wheat and Aegilops species. Specifically, Ae. neglecta and Ae. triuncialis showed significantly more admixed individuals close to wheat fields than in locations isolated from agriculture. In contrast, little evidence of gene flow was found in Ae. geniculata. Our results indicated that reproductive barriers have been regularly bypassed during the long history of sympatry between wheat and Aegilops. PMID:25568015

  11. Changes of phenolic acids and antioxidant activities during potherb mustard (Brassica juncea, Coss.) pickling.

    PubMed

    Fang, Zhongxiang; Hu, Yuxia; Liu, Donghong; Chen, Jianchu; Ye, Xingqian

    2008-06-01

    Phenolic acids in potherb mustard (Brassica juncea, Coss.) were determined and the effects of pickling methods on the contents of total free phenolic acids, total phenolic acids, total phenolics, and antioxidant activities were investigated. Gallic acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, p-coumaric acid, ferulic acid, and sinapic acid were identified in the present study. The contents of total free phenolic acids, total phenolic acids and total phenolics in fresh potherb mustard were 84.8±0.58μg/g dry weight (DW), 539±1.36μg/g DW, and 7.95±0.28mg/g DW, respectively. The total free phenolic acids increased during the pickling processes, but the total phenolic acids, total phenolics, and antioxidant activities decreased. However, after 5 weeks of fermentation, all the pickling methods retained over 70% of total phenolic contents and above 65% of antioxidant capacities. The results indicated that pickling processes were relatively good methods for the preservation of phenolic acids and antioxidants for potherb mustard. PMID:26065739

  12. Ion beam analysis and co-sputtering simulation (CO-SS) of bi-metal films produced by magnetron co-sputtering

    NASA Astrophysics Data System (ADS)

    Cruz, J.; Andrade, E.; Muhl, S.; Canto, C.; de Lucio, O.; Chávez, E.; Rocha, M. F.; Garcés-Medina, E.

    2016-03-01

    Magnetron sputtering is widely used to deposit thin films on different types of substrates. An important application of this method is to make multicomponent thin films using co-sputtering, where two or more elements are included in the target. The thickness and elemental composition of the films depend on the experimental parameters used, the system geometry and the spatial distribution of the elements in the target. If the target is made of two spatially separate pieces of the materials, then the composition of the deposit depends on a combination of the relative areas, the sputtering yield and the angular distribution of the emission of the sputtered flux of each material. In this work, a co-sputtering simulation program, known as CO-SS, was developed to simulate the thickness and composition of metal films produced by DC magnetron sputtering (Al) and co-sputtering (Al + Ti). The CO-SS code models the angular distribution of particles ejected by sputtering from the target, where this is assumed to vary as cosn β , where n is a free parameter and β is the angle of ejection relative to the normal to the surface of the target, and the sputtering yield of each material. The program also takes into account other geometry factors such as the distance between the target and the substrate, and the size of the substrate. Rutherford backscattering (RBS) using 4He was employed to measure the thickness and the composition of the films deposited on glass cover slides in order to assess the CO-SS program. The film thickness was also measured by profilometry. The CO-SS code was found to accurately model the experimental results for both the Al and Ti/Al films. The CO-SS code is freely available for use from http://demonstrations.wolfram.com/CoSputteringSimulationCOSS/.

  13. RESISTANCE OF SHARON GOATGRASS (AEGILOPS SHARONENSIS) TO FUNGAL DISEASES OF WHEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sharon goatgrass (Aegilops sharonensis) is a wild relative of wheat that is native to Israel and Lebanon. The importance of Ae. sharonensis as a source of new resistance genes for wheat warrants additional research on the characterization of accessions for economically important genes. Thus, the obj...

  14. New source of TTKSK resistance derived from Thinopyrum and Aegilops species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several stem rust resistance genes of Thinopyrum and Aegilops origins appeared to be highly effective against race TTKSK (or Ug99) of Puccinia graminis f. sp. tritici. We evaluated and characterized the seedling resistance to TTKSK of 62 wheat lines derived from crosses of common or durum wheat with...

  15. A cryptic wheat–Aegilops triuncialis translocation with leaf rust resistance gene Lr58

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genes transferred to crop plants from wild species are often associated with deleterious traits. Using molecular markers, we detected a cryptic introgression with a leaf rust resistance gene transferred from Aegilops triuncialis L. into common wheat (Triticum aestivum L.). One agronomically desirabl...

  16. Introgression of a New Stem Rust Resistance Gene from Aegilops markgrafii into Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In a prior study, we reported that an Alcedo/Aegilops markgrafii disomic addition line, AIII(D) (2n=44), was resistant to three races of the Ug99 lineage and five North American races of stem rust pathogen in wheat and the resistance originated from the alien chromosome. In this study, our objectiv...

  17. Antioxidant and Anti-inflammatory Properties of Algerian Thymelaea microphylla Coss. and Dur. Extracts

    PubMed Central

    Dehimi, Khadidja; Speciale, Antonio; Saija, Antonina; Dahamna, Saliha; Raciti, Roberto; Cimino, Francesco; Cristani, Mariateresa

    2016-01-01

    Background: Thymelaea microphylla Coss. et Dur. (Thymelaeaceae) (TM) is a rare medicinal plant endemic to Algeria. Leaves decoction is used in folk medicine for anticancer, anti-inflammatory, and antidiabetic properties. Objective: Herein, the antioxidant and anti-inflammatory properties of different extracts from leaves and flowers of Algerian TM were evaluated. Materials and Methods: The study was carried out by in vitro cell-free assays (antioxidant/radical properties), ex vivo experiments (inhibition of prostaglandin E2 and thromboxane B2 release in human whole blood) and in vitro experiments on cell systems (cytotoxicity on peripheral blood mononuclear cells, and protective effects on human vein endothelial cells exposed to TNF-α). Results: The acetone TM extract showed significant antioxidant properties and excellent anti-inflammatory and cyclooxygenase-inhibitory activity, together with lack of toxicity on normal human blood cells; furthermore, it was able to protect endothelial cells against dysfunction induced by TNF-α, as shown by decrease in cell death, e-selectin expression and leukocyte adhesion. Conclusion: On these bases, TM leaves and flowers appear to be a good source of bioactive compounds with significant antioxidant and antiinflammatory capability, and potentially effective in prevention and treatment of pathological conditions related to oxidative stress and inflammation, such as endothelial dysfunction. SUMMARY Thymelaea microphylla leaves and flowers are a good source of bioactive compounds with significant antioxidant/free radical scavenger and antiinflammatory activity.The acetone extract from leaves and flowers of Algerian Thymelaea microphylla possesses excellent cyclooxygenase-inhibitory activity.This extract is able to protect against endothelial dysfunction, an early event in development of atherosclerosis and vascular diseases. Abbreviations used: TM: Thymelaea microphylla; BCB: Beta-carotene bleaching; AcE: Acetone extract; PGE2

  18. Identification of a major QTL controlling the content of B-type starch granules in Aegilops

    PubMed Central

    Howard, Thomas; Rejab, Nur Ardiyana; Griffiths, Simon; Leigh, Fiona; Leverington-Waite, Michelle; Simmonds, James; Uauy, Cristobal; Trafford, Kay

    2011-01-01

    Starch within the endosperm of most species of the Triticeae has a unique bimodal granule morphology comprising large lenticular A-type granules and smaller near-spherical B-type granules. However, a few wild wheat species (Aegilops) are known to lack B-granules. Ae. peregrina and a synthetic tetraploid Aegilops with the same genome composition (SU) were found to differ in B-granule number. The synthetic tetraploid had normal A- and B-type starch granules whilst Ae. peregrina had only A-granules because the B-granules failed to initiate. A population segregating for B-granule number was generated by crossing these two accessions and was used to study the genetic basis of B-granule initiation. A combination of Bulked Segregant Analysis and QTL mapping identified a major QTL located on the short arm of chromosome 4S that accounted for 44.4% of the phenotypic variation. The lack of B-granules in polyploid Aegilops with diverse genomes suggests that the B-granule locus has been lost several times independently during the evolution of the Triticeae. It is proposed that the B-granule locus is susceptible to silencing during polyploidization and a model is presented to explain the observed data based on the assumption that the initiation of B-granules is controlled by a single major locus per haploid genome. PMID:21227932

  19. Synthesizing double haploid hexaploid wheat populations based on a spontaneous alloploidization process.

    PubMed

    Zhang, Lianquan; Zhang, Li; Luo, Jiangtao; Chen, Wenjie; Hao, Ming; Liu, Baolong; Yan, Zehong; Zhang, Bo; Zhang, Huaigang; Zheng, Youliang; Liu, Dengcai; Yen, Yang

    2011-02-01

    Doubled haploid (DH) populations are useful to scientists and breeders in both crop improvement and basic research. Current methods of producing DHs usually need in vitro culture for extracting haploids and chemical treatment for chromosome doubling. This report describes a simple method for synthesizing DHs (SynDH) especially for allopolyploid species by utilizing meiotic restitution genes. The method involves three steps: hybridization to induce recombination, interspecific hybridization to extract haploids, and spontaneous chromosome doubling by selfing the interspecific F(1)s. DHs produced in this way contain recombinant chromosomes in the genome(s) of interest in a homogeneous background. No special equipment or treatments are involved in the DH production and it can be easily applied in any breeding and/or genetic program. Triticum turgidum L. and Aegilops tauschii Coss, the two ancestral species of common wheat (Triticum aestivum L.) and molecular markers were used to demonstrate the SynDH method. PMID:21356528

  20. Chemical composition and antibacterial activity of the essential oils of Ferula vesceritensis Coss et Dur. leaves, endemic in Algeria

    PubMed Central

    2012-01-01

    Background The biological importance of members of genus Ferula promoted us to investigate the leaves of Ferula vesceritensis Coss et Dur. (endemic plant) previously not investigated. This study presents the chemical composition and antibacterial activities of the hydrodistilled oils. Results Volatile components of the leaves of F. vesceritensis have been studied by gas chromatography–mass spectrometry to afford 23 compounds. The major components were found to be 5,9-tetradecadiyne (24.72%), germacrene D (24.51%), farnesene (8.57%), and α-bisabolene (8.57%). The antimicrobial activities of the essential oils were evaluated by disk diffusion method and tested against Gram-positive and Gram-negative bacteria. The volatile oil showed a strong antibacterial activity against Staphylococcus aureus, Escherichia coli, and Klebsiella pneumonia. Conclusions These results reinforce the previous studies showing that the genus Ferula is considered as a good source of essential oils. The results presented here can be considered as the first information on the antimicrobial properties of F. vesceritensis. PMID:22937773

  1. Molecular marker-assisted alien gene introgression of Sr39 for wheat stem rust resistance derived from Aegilops speltoides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In wheat (Triticum aestivum L.), stem rust resistance gene Sr39, derived from Aegilops speltoides, is highly effective against multiple stem rust races including Ug99. However, the gene has not been used in wheat breeding because it is located on a large 2S chromosomal segment in the current transl...

  2. Transmission of the Aegilops ovata chromosomes carrying gametocidal factors in hexaploid triticale (×Triticosecale Wittm.) hybrids.

    PubMed

    Kwiatek, M; Majka, M; Ślusarkiewicz-Jarzina, A; Ponitka, A; Pudelska, H; Belter, J; Wiśniewska, H

    2016-08-01

    The main aim of this work was to induce the chromosome rearrangements between Aegilops ovata (UUMM) and hexaploid triticale (AABBRR) by expression of the gametocidal factor located on the chromosome 4M. The Aegilops ovata × Secale cereale (UUMMRR) amphiploids and triticale 'Moreno' were used to produce hybrids by reciprocal crosses. Chromosome dynamics was observed in subsequent generations of hybrids during mitotic metaphase of root meristems and first metaphase of meiosis of pollen mother cells. Chromosomes were identified by genomic in situ hybridisation (GISH) and fluorescence in situ hybridisation (FISH) using pTa71, pTa791, pSc119.2 and pAs1 DNA probes. It has been shown that the origin of the genetic background had an influence on Aegilops chromosome transmission. Moreover, it has been reported that the preferential transmission of chromosome 4M appeared during both androgenesis and gynogenesis. It is also hypothesised that the expression of the triticale Gc gene suppressor had an influence on the semi-fertility of hybrids but did not inhibit the chromosome rearrangements. This paper also describes the double haploid production, which enabled to obtain plants with two identical copies of triticale chromosomes with translocations of Aegilops chromatin segments. PMID:26825077

  3. Introgression of leaf rust and stripe rust resistance from Sharon goatgrass (Aegilops sharonensis Eig) into bread wheat (Triticum aestivum L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaf rust and stripe rust are devastating wheat diseases, causing significant yield losses in many regions of the world. The use of resistant varieties is the most efficient way to protect wheat crops from these diseases. Sharon goatgrass (Aegilops sharonensis or AES), which is a diploid wild relati...

  4. Molecular Cytogenetic Mapping of Satellite DNA Sequences in Aegilops geniculata and Wheat.

    PubMed

    Koo, Dal-Hoe; Tiwari, Vijay K; Hřibová, Eva; Doležel, Jaroslav; Friebe, Bernd; Gill, Bikram S

    2016-01-01

    Fluorescence in situ hybridization (FISH) provides an efficient system for cytogenetic analysis of wild relatives of wheat for individual chromosome identification, elucidation of homoeologous relationships, and for monitoring alien gene transfers into wheat. This study is aimed at developing cytogenetic markers for chromosome identification of wheat and Aegilops geniculata (2n = 4x = 28, UgUgMgMg) using satellite DNAs obtained from flow-sorted chromosome 5Mg. FISH was performed to localize the satellite DNAs on chromosomes of wheat and selected Aegilops species. The FISH signals for satellite DNAs on chromosome 5Mg were generally associated with constitutive heterochromatin regions corresponding to C-band-positive chromatin including telomeric, pericentromeric, centromeric, and interstitial regions of all the 14 chromosome pairs of Ae. geniculata. Most satellite DNAs also generated FISH signals on wheat chromosomes and provided diagnostic chromosome arm-specific cytogenetic markers that significantly improved chromosome identification in wheat. The newly identified satellite DNA CL36 produced localized Mg genome chromosome-specific FISH signals in Ae. geniculata and in the M genome of the putative diploid donor species Ae. comosa subsp. subventricosa but not in Ae. comosa subsp. comosa, suggesting that the Mg genome of Ae. geniculata was probably derived from subsp. subventricosa. PMID:27403741

  5. Study of the repeatability of histone genes in the ploidy series of wheat and Aegilops

    SciTech Connect

    Vakhitov, V.A.; Kulikov, A.M.

    1986-10-01

    The hDNA content and number of histone genes in the genomes of different wheat and Aegilops species have been determined by molecular hybridization of DNA with /sup 125/I-histone DNA of Drosophila (L-repeat) on nitrocellulose filters. It has been demonstrated that the proportion of hDNA in the total DNA of diploid and polyploid wheat species is (1.3-7.7) x 10/sup -3/% (57-850 genes), and in the ploidy series of Aegilops species (2.0-8.0) x 10/sup -3/% (89-780 genes). The repeatability of the histone genes generally increases at each ploidy level in the species with higher DNA content. At the same time, it has been demonstrated that the DNA content is not the only factor determining repeatability of the histone genes, as some diploid and allopolyploid species have similar number of these genes. It has been concluded that genetic mechanisms are involved in the regulation of the number of histone genes.

  6. [Hybrids of Aegilops cylindrica Host with Triticum durum Desf. and T. aestivum L].

    PubMed

    Avsenin, V I; Motsnyĭ, A I; Rybalka, A I; Faĭt, V I

    2003-01-01

    The hybrids of durum and bread wheat with Ae. cylindrica have been obtained without using an embryo rescue technique. The hybrid output (of pollinated flower number) in the field conditions scored 1.0, 15.3 and 10.0% in the crosses T. durum x Ae. cylindrica, Ae. cylindrica x T. durum and T. aestivum x Ae. cylindrica, respectively. A high level of meiotic chromosome pairing between homologous D genomes of bread wheat and Aegilops has been revealed (c = 80.0-83.7%). The possibility of homoeological pairing between wheat and Ae. cylindrica chromosomes has been shown. Herewith, the correlation between the levels of homological and homoeological pairing is absent. The possibilities of genetic material interchange, including between the tetraploid species, as well as the using of Ae. cylindrica cytoplasm for durum wheat breeding are discussed. PMID:12741056

  7. Genome-specific introgression between wheat and its wild relative Aegilops triuncialis.

    PubMed

    Parisod, C; Definod, C; Sarr, A; Arrigo, N; Felber, F

    2013-01-01

    Introgression of sequences from crop species in wild relatives is of fundamental and practical concern. Here, we address gene flow between cultivated wheat and its widespread polyploid relative, Aegilops triuncialis, using 12 EST-SSR markers mapped on wheat chromosomes. The presence of wheat diagnostic alleles in natural populations of the barbed goatgrass growing in proximity to cultivated fields highlights that substantial gene flow occurred when both species coexisted. Furthermore, loci from the A subgenome of wheat were significantly less introgressed than sequences from other subgenomes, indicating differential introgression into Ae. triuncialis. Gene flow between such species sharing nonhomeologous chromosomes addresses the evolutionary outcomes of hybridization and may be important for efficient gene containment. PMID:23205963

  8. B Chromosomes of Aegilops speltoides Are Enriched in Organelle Genome-Derived Sequences

    PubMed Central

    Ruban, Alevtina; Fuchs, Jörg; Marques, André; Schubert, Veit; Soloviev, Alexander; Raskina, Olga; Badaeva, Ekaterina; Houben, Andreas

    2014-01-01

    B chromosomes (Bs) are dispensable components of the genome exhibiting non-Mendelian inheritance. Chromosome counts and flow cytometric analysis of the grass species Aegilops speltoides revealed a tissue-type specific distribution of the roughly 570 Mbp large B chromosomes. To address the question whether organelle-to-nucleus DNA transfer is a mechanism that drives the evolution of Bs, in situ hybridization was performed with labelled organellar DNA. The observed B-specific accumulation of chloroplast- and mitochondria-derived sequences suggests a reduced selection against the insertion of organellar DNA in supernumerary chromosomes. The distribution of B-localised organellar-derived sequences and other sequences differs between genotypes of different geographical origins. PMID:24587288

  9. Grain protein variability among species of Triticum and Aegilops: quantitative SDS-PAGE studies.

    PubMed

    Cole, E W; Fullington, J G; Kasarda, D D

    1981-01-01

    Total proteins were extracted from degermed seeds of various species of Triticum and Aegilops with solutions containing sodium dodecyl sulfate (SDS) and mercaptoethanol. The reduced, dissociated proteins were fractionated according to molecular weight (MW) by high-resolution polyacrylamide gel electrophoresis in buffers containing SDS (SDS-PAGE). Stained SDS-PAGE patterns were measured by densitometric scanning over a suitable range of optical density. The data were normalized to equivalent total areas for each of the densitometric scans by means of a computer program that also permitted the construction of patterns of hypothetical amphiploids by averaging patterns of two or three diploid species. The grain proteins of most species examined had distinctive qualitative and quantitative aspects that were characteristic of the species even though nearly every accession or cultivar of a species exhibited at least minor differences in pattern from other accessions or cultivars. The main protein components (probably prolamins) of Triticum monococcum ssp. monococcum, T. monococcum ssp. boeoticum, T. urartu, and Aegilops squarrosa had MW's in the range 29-36 X 10(3) whereas the most important components of Ae. speltoides, Ae. longissima, and Ae. searsii had MW's in the range 37-55 × 10(3). Changes in the quantitative expression of particular genes, especially those coding for storage protein components, may have been associated with speciation. The strong predominance of proteins with MW's in the range 29-36 × 10(3) in some accessions of AB genome tetraploids, such as T. turgidum ssp. dicoccoides, may indicate contributions to the B genome of these tetraploids by T. monococcum ssp. boeoticum, T. urartu, or Ae. squarrosa. PMID:24276584

  10. Expression of an endochitinase gene from Trichoderma virens confers enhanced tolerance to Alternaria blight in transgenic Brassica juncea (L.) czern and coss lines.

    PubMed

    Kamble, Suchita; Mukherjee, Prasun K; Eapen, Susan

    2016-01-01

    An endochitinase gene 'ech42' from the biocontrol fungus 'Trichoderma virens' was introduced to Brassica juncea (L). Czern and Coss via Agrobaterium tumefaciens mediated genetic transformation method. Integration and expression of the 'ech42' gene in transgenic lines were confirmed by PCR, RT-PCR and Southern hybridization. Transgenic lines (T1) showed expected 3:1 Mendelian segregation ratio when segregation analysis for inheritance of transgene 'hpt' was carried out. Fluorimetric analysis of transgenic lines (T0 and T1) showed 7 fold higher endochitinase activity than the non-transformed plant. Fluorimetric zymogram showed presence of endochitinase (42 kDa) in crude protein extract of transgenic lines. In detached leaf bioassay with fungi Alternaria brassicae and Alternaria brassicicola, transgenic lines (T0 and T1) showed delayed onset of lesions as well as 30-73 % reduction in infected leaf area compared to non-transformed plant. PMID:27186020

  11. [The detection of nonallelic to known genes of resistance to Tilletia caries (DC) Tul. in wheat strains from interspecific hybridization (Triticum aestivum x Aegilops cylindrica)].

    PubMed

    Babaiants, L T; Dubinina, L A; Iushchenko, G M

    2000-01-01

    It was established by hybridological analysis that winter bread wheat lines 1/74-91, 3/36-91, 5/55-91 possess single dominant gene of resistance to bunt (Tilletia caries (DC) Tul.), but lines 8/2-91, 5/43-91, 4/11-91 and 8/16-91 have two independent dominant genes for this character. These genes originated from Aegilops cylindrica are not identical to Bt1-Bt17 genes and are unknown to date. The lines were obtained from crosses between winter bread wheat variety Odeskaya polukarlikovaya and Aegilops cylindrica. PMID:11033855

  12. Genetic effect of the Aegilops caudata plasmon on the manifestation of the Ae. cylindrica genome.

    PubMed

    Tsunewaki, Koichiro; Mori, Naoki; Takumi, Shigeo

    2014-01-01

    In the course of reconstructing Aegilops caudata from its own genome (CC) and its plasmon, which had passed half a century in common wheat (genome AABBDD), we produced alloplasmic Ae. cylindrica (genome CCDD) with the plasmon of Ae. caudata. This line, designated (caudata)-CCDD, was found to express male sterility in its second substitution backcross generation (SB2) of (caudata)-AABBCCDD pollinated three times with the Ae. cylindrica pollen. We repeatedly backcrossed these SB2 plants with the Ae. cylindrica pollen until the SB5 generation, and SB5F2 progeny were produced by self-pollination of the SB5 plants. Thirteen morphological and physiological characters, including pollen and seed fertilities, of the (caudata)-CCDD SB5F2 were compared with those of the euplasmic Ae. cylindrica. The results indicated that the male sterility expressed by (caudata)-CCDD was due to genetic incompatibility between the Ae. cylindrica genome and Ae. caudata plasmon that did not affect any other characters of Ae. cylindrica. Also, we report that the genome integrity functions in keeping the univalent transmission rate high. PMID:25832746

  13. Molecular analysis, cytogenetics and fertility of introgression lines from transgenic wheat to Aegilops cylindrica host.

    PubMed

    Schoenenberger, Nicola; Guadagnuolo, Roberto; Savova-Bianchi, Dessislava; Küpfer, Philippe; Felber, François

    2006-12-01

    Natural hybridization and backcrossing between Aegilops cylindrica and Triticum aestivum can lead to introgression of wheat DNA into the wild species. Hybrids between Ae. cylindrica and wheat lines bearing herbicide resistance (bar), reporter (gus), fungal disease resistance (kp4), and increased insect tolerance (gna) transgenes were produced by pollination of emasculated Ae. cylindrica plants. F1 hybrids were backcrossed to Ae. cylindrica under open-pollination conditions, and first backcrosses were selfed using pollen bags. Female fertility of F1 ranged from 0.03 to 0.6%. Eighteen percent of the sown BC1s germinated and flowered. Chromosome numbers ranged from 30 to 84 and several of the plants bore wheat-specific sequence-characterized amplified regions (SCARs) and the bar gene. Self fertility in two BC1 plants was 0.16 and 5.21%, and the others were completely self-sterile. Among 19 BC1S1 individuals one plant was transgenic, had 43 chromosomes, contained the bar gene, and survived glufosinate treatments. The other BC1S1 plants had between 28 and 31 chromosomes, and several of them carried SCARs specific to wheat A and D genomes. Fertility of these plants was higher under open-pollination conditions than by selfing and did not necessarily correlate with even or euploid chromosome number. Some individuals having supernumerary wheat chromosomes recovered full fertility. PMID:17028347

  14. Genetic differentiation and post-glacial establishment of the geographical distribution in Aegilops caudata L.

    PubMed

    Ohta, S

    2000-08-01

    Aegilops caudata L. is a diploid wild relative of wheat distributed over the north-eastern Mediterranean from Greece to northern Iraq. To elucidate the geographical differentiation pattern, 35 accessions derived from the entire distribution area were crossed with four Tester strains. Pollen fertility in the F1 hybrids varied from 0 to 96.3% among cross combinations, closely correlating with the geographical regions where the parental accessions were collected. Based on the intraspecific hybrid sterility, the present distribution area of Ae. caudata was divided into two geographical regions effectively isolated by the mountainous region lying between West Anatolia and Central Anatolia. The western region is composed of Greece and West Anatolia, while the eastern region consists of Central Anatolia, South Anatolia, East Anatolia and northern Iraq. The present results and the facts from recent palaeopalynological works suggest that during the maximum glacial period from 18,000 BP to 16,000 BP, Ae. caudata occurred in the two isolated regions, i.e., the region surrounding the Aegean Sea and the western Levant or some sheltered habitats in the East Taurus/Zagros mountains arc, and that it migrated into Central and East Anatolia from the latter regions as the climate became warmer. Furthermore, it is also suggested that the Levant populations now occur in the eastern region of the distribution, while those occurring in the Aegean Sea region during the last glacial period now occupy the western region of the distribution. PMID:11126567

  15. Quantum speciation in Aegilops: Molecular cytogenetic evidence from rDNA cluster variability in natural populations

    PubMed Central

    Raskina, Olga; Belyayev, Alexander; Nevo, Eviatar

    2004-01-01

    Data are presented on quantum speciation in the Sitopsis section of the genus Aegilops (Poaceae, Monocotyledones). Two small, peripheral, isolated, wild populations of annual cross-pollinated Ae. speltoides and annual self-pollinated Ae. sharonensis are located 30 m apart on different soil types. Despite the close proximity of the two species and their close relatedness, no mixed groups are known. Comparative molecular cytogenetic analysis based on the intrapopulation variability of rRNA-encoding DNA (rDNA) chromosomal patterns of individual Ae. speltoides geno-types revealed an ongoing dynamic process of permanent chromosomal rearrangements. Chromosomal mutations can arise de novo and can be eliminated. Analysis of the progeny of the investigated genotypes testifies that inheritance of de novo rDNA sites happens frequently. Heterologous recombination and/or transposable elements-mediated rDNA transfer seem to be the mechanisms for observed chromosomal repatterning. Consequently, several modified genomic forms, intermediate between Ae. speltoides and Ae. sharonensis, permanently arise in the studied wild population of Ae. speltoides, which make it possible to recognize Ae. sharonensis as a derivative species of Ae. speltoides, as well as to propose rapidness and canalization of quantum speciation in Sitopsis species. PMID:15466712

  16. Diversity of fungal endophytes in recent and ancient wheat ancestors Triticum dicoccoides and Aegilops sharonensis.

    PubMed

    Ofek-Lalzar, Maya; Gur, Yonatan; Ben-Moshe, Sapir; Sharon, Or; Kosman, Evsey; Mochli, Elad; Sharon, Amir

    2016-10-01

    Endophytes have profound impacts on plants, including beneficial effects on agriculturally important traits. We hypothesized that endophytes in wild plants include beneficial endophytes that are absent or underrepresented in domesticated crops. In this work, we studied the structure of endophyte communities in wheat-related grasses, Triticum dicoccoides and Aegilops sharonensis, and compared it to an endophyte community from wheat (T. aeastivum). Endophytes were isolated by cultivation and by cultivation-independent methods. In total, 514 intergenic spacer region sequences from single cultures were analyzed. Categorization at 97% sequence similarity resulted in 67 operational taxonomic units (OTUs) that were evenly distributed between the different plant species. A narrow core community of Alternaria spp. was found in all samples, but each plant species also contained a significant portion of unique endophytes. The cultivation-independent analysis identified a larger number of OTUs than the cultivation method, half of which were singletons or doubletons. For OTUs with a relative abundance >0.5%, similar numbers were obtained by both methods. Collectively, our data show that wild grass relatives of wheat contain a wealth of taxonomically diverse fungal endophytes that are not found in modern wheat, some of which belong to taxa with known beneficial effects. PMID:27402714

  17. Partial characterization of glutathione S-transferases from wheat (Triticum spp.) and purification of a safener-induced glutathione S-transferase from Triticum tauschii.

    PubMed Central

    Riechers, D E; Irzyk, G P; Jones, S S; Fuerst, E P

    1997-01-01

    Hexaploid wheat (Triticum aestivum L.) has very low constitutive glutathione S-transferase (GST) activity when assayed with the chloroacetamide herbicide dimethenamid as a substrate, which may account for its low tolerance to dimethenamid in the field. Treatment of seeds with the herbicide safener fluxofenim increased the total GST activity extracted from T. aestivum shoots 9-fold when assayed with dimethenamid as a substrate, but had no effect on glutathione levels. Total GST activity in crude protein extracts from T. aestivum, Triticum durum, and Triticum tauschii was separated into several component GST activities by anion-exchange fast-protein liquid chromatography. These activities (isozymes) differed with respect to their activities toward dimethenamid or 1-chloro-2,4-dinitrobenzene as substrates and in their levels of induction by safener treatment. A safener-induced GST isozyme was subsequently purified by anion-exchange and affinity chromatography from etiolated shoots of the diploid wheat species T. tauschii (a progenitor of hexaploid wheat) treated with the herbicide safener cloquintocet-mexyl. The isozyme bound to a dimethenamid-affinity column and had a subunit molecular mass of 26 kD based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified enzyme (designated GST TSI-1) was recognized by an antiserum raised against a mixture of maize (Zea mays) GSTs. Amino acid sequences obtained from protease-digested GST TSI-1 had significant homology with the safener-inducible maize GST V and two auxin-regulated tobacco (Nicotiana tabacum) GST isozymes. PMID:9276955

  18. [Effect of an introgression from Aegilops cylindrica host on manifestation of productivity traits in winter common wheat F2 plants].

    PubMed

    Kozub, N A; Sozinov, I A; sozinov, A A

    2004-12-01

    The effect of introgression of a chromosome 1D segment from Aegilops cylindrica to winter common wheat on productivity traits in F2 plants was studied using storage protein loci as genetic markers. An allele of the gliadin-coding Gli-D1 locus served as a marker of the introgression. Using of two- and three-locus interaction models, it was shown that the introgression tagged with Gli-D1 affected the manifestation of productivity traits (productive tillering, grain weight per plant and grain number per plant) through interaction with other marker storage protein loci: Glu-B1, Glu-D1, and Gli-B2. PMID:15648149

  19. Development of wheat-Aegilops speltoides recombinants and simple PCR-based markers for stem rust resistance genes on the 2S#1 chromosome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wild relatives of wheat are important but underutilized resources for new rust resistance genes because linked negative traits often hinder deployment of these genes in commercial wheats. Here we report reduced alien chromatin recombinants derived from E.R. Sears wheat-Aegilops speltoides translocat...

  20. Characterization and mapping of cryptic alien introgression from Aegilops geniculata with new leaf rust and stripe rust resistance genes Lr57 and Yr40 in wheat.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaf rust and stripe rust are important foliar diseases of wheat worldwide. Leaf rust and stripe rust resistant introgression lines were developed by induced homoeologous chromosome pairing between wheat chromosome 5D and 5Mg of Aegilops geniculata (UgMg). Characterization of rust resistant BC2F5 a...

  1. Development of a diagnostic co-dominant marker for stem rust resistance gene Sr47 introgressed from Aegilops speltoides into durum wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stem rust (caused by Puccinia graminis f. sp. tritici, abbreviated as Pgt) resistance gene Sr47, originally transferred from Aegilops speltoides to durum wheat (Triticum turgidum subsp. durum) line DAS15, confers a high level of resistance to Pgt race TTKSK (known as Ug99). Recently, the durum Rust...

  2. 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...

  3. Development of wheat-Aegilops speltoides recombinants and simple PCR-based markers for stem rust resistance genes on the 2S#1 chromosome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wild relatives of wheat are important but underutilized resources for new rust resistance genes because linked negative traits often hinder deployment of these genes in commercial wheats. Here we report reduced alien chromatin recombinants derived from E.R. Sears' wheat-Aegilops speltoides transloca...

  4. Genetic compensation abilities of Aegilops speltoides chromosomes for homoeologous B-genome chromosomes of polyploid wheat in disomic S(B) chromosome substitution lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The S genome of Aegilops speltoides is closely related to the B and G genomes of polyploid wheats. However, little work has been reported on the genetic relationships between the S-genome and B-genome chromosomes of polyploid wheat. Here we report the isolation of a set of disomic substitutions (DS)...

  5. Chromosome evolution in marginal populations of Aegilops speltoides: causes and consequences

    PubMed Central

    Belyayev, Alexander; Raskina, Olga

    2013-01-01

    Background Genome restructuring is an ongoing process in natural plant populations. The influence of environmental changes on the genome is crucial, especially during periods of extreme climatic fluctuations. Interactions between the environment and the organism manifest to the greatest extent at the limits of the species' ecological niche. Thus, marginal populations are expected to exhibit lower genetic diversity and higher genetic differentiation than central populations, and some models assume that marginal populations play an important role in the maintenance and generation of biological diversity. Scope In this review, long-term data on the cytogenetic characteristics of diploid Aegilops speltoides Tauch populations are summarized and discussed. This species is distributed in and around the Fertile Crescent and is proposed to be the wild progenitor of a number of diploid and polyploid wheat species. In marginal populations of Ae. speltoides, numerical chromosomal aberrations, spontaneous aneuploidy, B-chromosomes, rDNA cluster repatterning and reduction in the species-specific and tribe-specific tandem repeats have been detected. Significant changes were observed and occurred in parallel with changes in plant morphology and physiology. Conclusions Considerable genomic variation at the chromosomal level was found in the marginal populations of Ae. speltoides. It is likely that a specific combination of gene mutations and chromosomal repatterning has produced the evolutionary trend in each specific case, i.e. for a particular species or group of related species in a given period of time and in a certain habitat. The appearance of a new chromosomal pattern is considered an important factor in promoting the emergence of interbreeding barriers. PMID:23393097

  6. Allopolyploidy-induced rapid genome evolution in the wheat (Aegilops-Triticum) group.

    PubMed

    Ozkan, H; Levy, A A; Feldman, M

    2001-08-01

    To better understand genetic events that accompany allopolyploid formation, we studied the rate and time of elimination of eight DNA sequences in F1 hybrids and newly formed allopolyploids of Aegilops and TRITICUM: In total, 35 interspecific and intergeneric F1 hybrids and 22 derived allopolyploids were analyzed and compared with their direct parental plants. The studied sequences exist in all the diploid species of the Triticeae but occur in only one genome, either in one homologous pair (chromosome-specific sequences [CSSs]) or in several pairs of the same genome (genome-specific sequences [GSSs]), in the polyploid wheats. It was found that rapid elimination of CSSs and GSSs is a general phenomenon in newly synthesized allopolyploids. Elimination of GSSs was already initiated in F1 plants and was completed in the second or third allopolyploid generation, whereas elimination of CSSs started in the first allopolyploid generation and was completed in the second or third generation. Sequence elimination started earlier in allopolyploids whose genome constitution was analogous to natural polyploids compared with allopolyploids that do not occur in nature. Elimination is a nonrandom and reproducible event whose direction was determined by the genomic combination of the hybrid or the allopolyploid. It was not affected by the genotype of the parental plants, by their cytoplasm, or by the ploidy level, and it did not result from intergenomic recombination. Allopolyploidy-induced sequence elimination occurred in a sizable fraction of the genome and in sequences that were apparently noncoding. This finding suggests a role in augmenting the differentiation of homoeologous chromosomes at the polyploid level, thereby providing the physical basis for the diploid-like meiotic behavior of newly formed allopolyploids. In our view, this rapid genome adjustment may have contributed to the successful establishment of newly formed allopolyploids as new species. PMID:11487689

  7. UHPLC-PDA-ESI/HRMS/MSn Analysis of Anthocyanins, Flavonol Glycosides, and Hydroxycinnamic Acid Derivatives in Red Mustard Greens (Brassica juncea Coss Variety)

    PubMed Central

    Lin, Long-Ze; Sun, Jianghao; Chen, Pei; Harnly, James

    2013-01-01

    An UHPLC-PDA-ESI/HRMS/MSn profiling method was used for a comprehensive study of the phenolic components of red mustard greens (Brassica juncea Coss variety) and identified 67 anthocyanins, 102 flavonol glycosides, and 40 hydroxycinnamic acid derivatives. The glycosylation patterns of the flavonoids were assigned on the basis of direct comparison of the parent flavonoid glycosides with reference compounds. The putative identifications were obtained from tandem mass data analysis and confirmed by the retention time, elution order, and UV–vis and high-resolution mass spectra. Further identifications were made by comparing the UHPLC-PDA-ESI/HRMS/MSn data with those of reference compounds in the polyphenol database and in the literature. Twenty-seven acylated cyanidin 3-sophoroside-5-diglucosides, 24 acylated cyanidin 3-sophoroside-5- glucosides, 3 acylated cyanidin triglucoside-5-glucosides, 37 flavonol glycosides, and 10 hydroxycinnamic acid derivatives were detected for the first time in brassica vegetables. At least 50 of them are reported for the first time in any plant materials. PMID:21970730

  8. NAD-dependent aromatic alcohol dehydrogenase in wheats (Triticum L.) and goatgrasses (Aegilops L.): evolutionary genetics.

    PubMed

    Jaaska, V

    1984-04-01

    Evolutionary electrophoretic variation of a NAD-specific aromatic alcohol dehydrogenase, AADH-E, in wheat and goatgrass species is described and discussed in comparison with a NAD-specific alcohol dehydrogenase (ADH-A) and a NADP-dependent AADH-B studied previously. Cultivated tetraploid emmer wheats (T. turgidum s. l.) and hexaploid bread wheats (T. aestivum s. l.) are all fixed for a heterozygous triplet, E(0.58)/E(0.64). The slowest isoenzyme, E(0.58), is controlled by a homoeoallelic gene on the chromosome arm 6AL of T. aestivum cv. 'Chinese Spring' and is inherent in all diploid wheats, T. monococcum s. Str., T. boeoticum s. l. and T. urartu. The fastest isoenzyme, E(0.64), is presumably controlled by the B- and D-genome homoeoalleles of the bread wheat and is the commonest alloenzyme of diploid goat-grasses, including Ae. speltaides and Ae. tauschii. The tetraploid T. timopheevii s. str. has a particular heterozygous triplet E(0.56)/E(0.71), whereas the hexaploid T. zhukovskyi exhibited polymorphism with electromorphs characteristic of T. timopheevii and T. monococcum. Wild tetraploid wheats, T. dicoccoides and T. araraticum, showed partially homologous intraspecific variation of AADH-E with heterozygous triplets E(0.58)/E(0.64) (the commonest), E(0.58)/E(0.71), E(0.45)/E(0.58), E(0.48)/E(0.58) and E(0.56)/E(0.58) recorded. Polyploid goatgrasses of the D-genome group, excepting Ae. cylindrica, are fixed for the common triplet E(0.58)/E(0.64). Ae. cylindrica and polyploid goatgrasses of the C(u)-genome group, excepting Ae. kotschyi, are homozygous for E(0.64). Ae. kotschyi is exceptional, showing fixed heterozygosity for both AADH-E and ADH-A with unique triplets E(0.56)/E(0.64) and A(0.49)/A(0.56). PMID:24258843

  9. [Molecular marker mapping of the gene resistant to common bunt transferred from Aegilops cylindrica into bread wheat].

    PubMed

    Galaev, A V; Babaiants, L T; Sivolap, Iu M

    2006-01-01

    Introgression lines 5/55-91 and 378/2000 of bread wheat contain the gene of resistance to Tilletia caries (DC.) Tul. transferred from Aegilops cylindrica Host. Using bulked segregant analysis with ISSR and SSR PCR the lincage of microsatellite locus Xgwm 259 with the gene of common bunt resistance has been identified in F2 population of 378/2000 x Lutestens 23397. DNA mapping made it possible to localize this highly effective gene in the intercalary region of the long arm of wheat chromosome 1B at the distance of 7.6-8.5 cM of the microsatellite Xgwm 259 locus which thus can be used in wheat breeding for selection of genotype resistance to common bunt. PMID:16865982

  10. Wheat phylogeny determined by RFLP analysis of nuclear DNA. 3. Intra- and interspecific variations of five Aegilops Sitopsis species.

    PubMed

    Sasanuma, T; Miyashita, N T; Tsunewaki, K

    1996-06-01

    The level of intra- and interspecific variations on nuclear DNA in five Aegilops species of the Sitopsis section were investigated using restriction fragment length polymorphism (RFLP) analysis. A total of 18 accessions, i.e. 7 of Ae. speltoides, 3 of Ae. longissima, 2 of Ae. searsii, 3 of Ae. sharonensis and 3 of Ae. bicornis, were used. One accession each of Triticum aestivum, T. durum, T. urartu and Ae. squarrosa was included as reference material. Five enzymes and 20 probes were used. Among the five Sitopsis species studied, Ae. speltoides had the largest intraspecific variation (π=0.061), which was as high as the interspecific variation observed among the other four species. The section Sitopsis was divided into two distinct groups: one containing only Ae. speltoides and the other, Ae. longissima, Ae. searsii, Ae. sharonensis and Ae. bicornis. This grouping by RFLP analysis is in agreement with the taxonomical classification of the subsections. PMID:24166619

  11. Allocation of the S-genome chromosomes of Aegilops variabilis Eig. carrying powdery mildew resistance in triticale (× Triticosecale Wittmack).

    PubMed

    Kwiatek, M; Belter, J; Majka, M; Wiśniewska, H

    2016-03-01

    It has been hypothesized that the powdery mildew adult plant resistance (APR) controlled by the Pm13 gene in Aegilops longissima Schweinf. & Muschl. (S(l)S(l)) has been evolutionary transferred to Aegilops variabilis Eig. (UUSS). The molecular marker analysis and the visual evaluation of powdery mildew symptoms in Ae. variabilis and the Ae. variabilis × Secale cereale amphiploid forms (2n = 6x = 42, UUSSRR) showed the presence of product that corresponded to Pm13 marker and the lower infection level compared to susceptible model, respectively. This study also describes the transfer of Ae. variabilis Eig. (2n = 4x = 28, U(v)U(v)S(v)S(v)) chromosomes, carrying powdery mildew resistance, into triticale (× Triticosecale Wittm., 2n = 6x = 42, AABBRR) using Ae. variabilis × S. cereale amphiploid forms. The individual chromosomes of Ae. variabilis, triticale 'Lamberto' and hybrids were characterized by genomic and fluorescence in situ hybridization (GISH/FISH). The chromosome configurations of obtained hybrid forms were studied at first metaphase of meiosis of pollen mother cells (PMCs) using GISH. The statistical analysis showed that the way of S-genome chromosome pairing and transmission to subsequent hybrid generations was diploid-like and had no influence on chromosome pairing of triticale chromosomes. The cytogenetic study of hybrid forms were supported by the marker-assisted selection using Pm13 marker and visual evaluation of natural infection by Blumeria graminis, that allowed to select the addition or substitution lines of hybrids carrying chromosome 3S(v) which were tolerant to the powdery mildew infection. PMID:25868512

  12. Introgression of leaf rust and stripe rust resistance from Sharon goatgrass (Aegilops sharonensis Eig) into bread wheat (Triticum aestivum L.).

    PubMed

    Millet, E; Manisterski, J; Ben-Yehuda, P; Distelfeld, A; Deek, J; Wan, A; Chen, X; Steffenson, B J

    2014-06-01

    Leaf rust and stripe rust are devastating wheat diseases, causing significant yield losses in many regions of the world. The use of resistant varieties is the most efficient way to protect wheat crops from these diseases. Sharon goatgrass (Aegilops sharonensis or AES), which is a diploid wild relative of wheat, exhibits a high frequency of leaf and stripe rust resistance. We used the resistant AES accession TH548 and induced homoeologous recombination by the ph1b allele to obtain resistant wheat recombinant lines carrying AES chromosome segments in the genetic background of the spring wheat cultivar Galil. The gametocidal effect from AES was overcome by using an "anti-gametocidal" wheat mutant. These recombinant lines were found resistant to highly virulent races of the leaf and stripe rust pathogens in Israel and the United States. Molecular DArT analysis of the different recombinant lines revealed different lengths of AES segments on wheat chromosome 6B, which indicates the location of both resistance genes. PMID:25209724

  13. Transfer of useful variability of high grain iron and zinc from Aegilops kotschyi into wheat through seed irradiation approach.

    PubMed

    Verma, Shailender Kumar; Kumar, Satish; Sheikh, Imran; Malik, Sachin; Mathpal, Priyanka; Chugh, Vishal; Kumar, Sundip; Prasad, Ramasare; Dhaliwal, Harcharan Singh

    2016-03-01

    Purpose To transfer the 2S chromosomal fragment(s) of Aegilops kotschyi (2S(k)) into the bread wheat genome which could lead to the biofortification of wheat with high grain iron and zinc content. Materials and methods Wheat-Ae. kotschyi 2A/2S(k) substitution lines with high grain iron and zinc content were used to transfer the gene/loci for high grain Fe and Zn content into wheat using seed irradiation approach. Results Bread wheat plants derived from 40 krad-irradiated seeds showed the presence of univalents and multivalents during meiotic metaphase-I. Genomic in situ hybridization analysis of seed irradiation hybrid F2 seedlings showed several terminal and interstitial signals indicated the introgression of Ae. kotschyi chromosome segments. This proves the efficacy of seed radiation hybrid approach in gene transfer experiments. All the radiation-treated hybrid plants with high grain Fe and Zn content were analyzed with wheat group 2 chromosome-specific polymorphic simple sequence repeat markers to identify the introgression of small alien chromosome fragment(s). Conclusion Radiation-induced hybrids showed more than 65% increase in grain iron and 54% increase in Zn contents with better harvest index than the elite wheat cultivar WL711 indicating effective and compensating translocations of 2S(k) fragments into wheat genome. PMID:26883304

  14. Haploid production in durum wheat by the interaction of Aegilops kotschyi cytoplasm and 1BL/1RS chromosomal interchange.

    PubMed

    Hsam, S L; Zeller, F J

    1993-09-01

    The present study describes the development of an alloplasmic haploid-inducer in durum wheat cv 'Cando'. This cultivar possesses the homozygous wheat-rye translocation 1BL/1RS from the 6x-wheat cv 'Veery'. The nucleus of 4x-'Cando-Veery 1BL/1RS' was introduced into Aegilops kotschyi cytoplasm by initially using (kotschyi)-Salmon as the maternal parent. In the cross of this alloplasmic durum line with 'Cando-Veery 1BL/1RS', which was used as the recurrent pollen parent, haploids (n=14) were produced. The frequency of haploids increased from 5.7% in the F1 generation to 14% in the BC1 generation. The presence of rye chromosome arm 1RS and the concomitant loss of 1BS in '(kotschyi)-Cando-Veery 1BL/1RS' are necessary for haploid induction. Proposals are made which may enable the use of haploids produced by nucleo-cytoplasmic interactions in future wheat breeding programs. PMID:24194002

  15. De novo assembly and characterization of the root transcriptome of Aegilops variabilis during an interaction with the cereal cyst nematode

    PubMed Central

    2012-01-01

    Background Aegilops variabilis No.1 is highly resistant to cereal cyst nematode (CCN). However, a lack of genomic information has restricted studies on CCN resistance genes in Ae. variabilis and has limited genetic applications in wheat breeding. Results Using RNA-Seq technology, we generated a root transcriptome at a sequencing depth of 4.69 gigabases of Ae. variabilis No. 1 from a pooled RNA sample. The sample contained equal amounts of RNA extracted from CCN-infected and untreated control plants at three time-points. Using the Trinity method, nearly 52,081,238 high-quality trimmed reads were assembled into a non-redundant set of 118,064 unigenes with an average length of 500 bp and an N50 of 599 bp. The total assembly was 59.09 Mb of unique transcriptome sequences with average read-depth coverage of 33.25×. In BLAST searches of our database against public databases, 66.46% (78,467) of the unigenes were annotated with gene descriptions, conserved protein domains, or gene ontology terms. Functional categorization further revealed 7,408 individual unigenes and three pathways related to plant stress resistance. Conclusions We conducted high-resolution transcriptome profiling related to root development and the response to CCN infection in Ae. variabilis No.1. This research facilitates further studies on gene discovery and on the molecular mechanisms related to CCN resistance. PMID:22494814

  16. Characterization of a new wheat-Aegilops biuncialis addition line conferring quality-associated HMW glutenin subunits.

    PubMed

    Zhou, J P; Yao, C H; Yang, E N; Yin, M Q; Liu, C; Ren, Z L

    2014-01-01

    In this study, a new disomic addition line, 12-5-2, with 44 chromosomes that was derived from BC3F2 descendants of the hybridization between Triticum aestivum cv. CN19 and Aegilops biuncialis was created and reported. 12-5-2 was immune to both powdery mildew and stripe rust and has stable fertility. Fluorescence in situ hybridization and C-banding revealed that 12-5-2 was a 1U(b) disomic addition line (ADL1U(b)). The seed storage protein electrophoresis showed that 12-5-2 presented all high molecular weight glutenin subunits (7 + 8 and 2 + 12) of CN19 and 2 new subunits that were designated Ux and Uy. Additionally, the flour quality parameters showed that the protein content, Zeleny sedimentation value, wet gluten content, and grain hardness of 12-5-2 were significantly higher than those of its parent CN19. Moreover, 5 pairs of the chromosome 1U(b)-specific polymerase chain reaction-based landmark unique gene markers, TNAC1021, TNAC1041, TNAC1071, TNAC1-01, and TNAC1-04, were also obtained. The new ADL1U(b) 12-5-2 could be a valuable source for wheat improvement, especially for wheat end-product quality and resistance to disease. PMID:24615031

  17. Flow sorting of C-genome chromosomes from wild relatives of wheat Aegilops markgrafii, Ae. triuncialis and Ae. cylindrica, and their molecular organization

    PubMed Central

    Molnár, István; Vrána, Jan; Farkas, András; Kubaláková, Marie; Cseh, András; Molnár-Láng, Márta; Doležel, Jaroslav

    2015-01-01

    Background and Aims Aegilops markgrafii (CC) and its natural hybrids Ae. triuncialis (UtUtCtCt) and Ae. cylindrica (DcDcCcCc) represent a rich reservoir of useful genes for improvement of bread wheat (Triticum aestivum), but the limited information available on their genome structure and the shortage of molecular (cyto-) genetic tools hamper the utilization of the extant genetic diversity. This study provides the complete karyotypes in the three species obtained after fluorescent in situ hybridization (FISH) with repetitive DNA probes, and evaluates the potential of flow cytometric chromosome sorting. Methods The flow karyotypes obtained after the analysis of 4',6-diamidino-2-phenylindole (DAPI)-stained chromosomes were characterized and the chromosome content of the peaks on the flow karyotypes was determined by FISH. Twenty-nine conserved orthologous set (COS) markers covering all seven wheat homoeologous chromosome groups were used for PCR with DNA amplified from flow-sorted chromosomes and genomic DNA. Key Results FISH with repetitive DNA probes revealed that chromosomes 4C, 5C, 7Ct, T6UtS.6UtL-5CtL, 1Cc and 5Dc could be sorted with purities ranging from 66 to 91 %, while the remaining chromosomes could be sorted in groups of 2–5. This identified a partial wheat–C-genome homology for group 4 and 5 chromosomes. In addition, 1C chromosomes were homologous with group 1 of wheat; a small segment from group 2 indicated 1C–2C rearrangement. An extensively rearranged structure of chromosome 7C relative to wheat was also detected. Conclusions The possibility of purifying Aegilops chromosomes provides an attractive opportunity to investigate the structure and evolution of the Aegilops C genome and to develop molecular tools to facilitate the identification of alien chromatin and support alien introgression breeding in bread wheat. PMID:26043745

  18. Microsatellite Mutation Rate during Allohexaploidization of Newly Resynthesized Wheat

    PubMed Central

    Luo, Jiangtao; Hao, Ming; Zhang, Li; Chen, Jixiang; Zhang, Lianquan; Yuan, Zhongwei; Yan, Zehong; Zheng, Youliang; Zhang, Huaigang; Yen, Yang; Liu, Dengcai

    2012-01-01

    Simple sequence repeats (SSRs, also known as microsatellites) are known to be mutational hotspots in genomes. DNA rearrangements have also been reported to accompany allopolyploidization. A study of the effect of allopolyploidization on SSR mutation is therefore important for understanding the origin and evolutionary dynamics of SSRs in allopolyploids. Three synthesized double haploid (SynDH) populations were made from 241 interspecific F1 haploid hybrids between Triticum turgidum L. and Aegilops tauschii (Coss.) through spontaneous chromosome doubling via unreduced gametes. Mutation events were studied at 160 SSR loci in the S1 generation (the first generation after chromosome doubling) of the three SynDH populations. Of the 148260 SSR alleles investigated in S1 generation, only one mutation (changed number of repeats) was confirmed with a mutation rate of 6.74 × 10−6. This mutation most likely occurred in the respective F1 hybrid. In comparison with previously reported data, our results suggested that allohexaploidization of wheat did not increase SSR mutation rate. PMID:23202911

  19. Introgression of an imidazolinone-resistance gene from winter wheat (Triticum aestivum L.) into jointed goatgrass (Aegilops cylindrica Host).

    PubMed

    Perez-Jones, Alejandro; Mallory-Smith, Carol A; Hansen, Jennifer L; Zemetra, Robert S

    2006-12-01

    Imidazolinone-resistant winter wheat (Triticum aestivum L.) is being commercialized in the USA. This technology allows wheat growers to selectively control jointed goatgrass (Aegilops cylindrica Host), a weed that is especially problematic because of its close genetic relationship with wheat. However, the potential movement of the imidazolinone-resistance gene from winter wheat to jointed goatgrass is a concern. Winter wheat and jointed goatgrass have the D genome in common and can hybridize and backcross under natural field conditions. Since the imidazolinone-resistance gene (Imi1) is located on the D genome, it is possible for resistance to be transferred to jointed goatgrass via hybridization and backcrossing. To study the potential for gene movement, BC(2)S(2) plants were produced artificially using imidazolinone-resistant winter wheat (cv. FS-4) as the female parent and a native jointed goatgrass collection as the male recurrent parent. FS-4, the jointed goatgrass collection, and 18 randomly selected BC(2)S(2) populations were treated with imazamox. The percentage of survival was 100% for the FS-4, 0% for the jointed goatgrass collection and 6 BC(2)S(2) populations, 40% or less for 2 BC(2)S(2) populations, and 50% or greater for the remaining 10 BC(2)S(2) populations. Chromosome counts in BC(2)S(3) plants showed a restoration of the chromosome number of jointed goatgrass, with four out of four plants examined having 28 chromosomes. Sequencing of AHASL1D in BC(2)S(3) plants derived from BC(2)S(2)-6 revealed the sexual transmission of Imi1 from FS-4 to jointed goatgrass. Imi1 conferred resistance to the imidazolinone herbicide imazamox, as shown by the in vitro assay for acetohydroxyacid synthase (AHAS) activity. PMID:17058103

  20. Characterisation and Analysis of the Aegilops sharonensis Transcriptome, a Wild Relative of Wheat in the Sitopsis Section

    PubMed Central

    Bouyioukos, Costas; Moscou, Matthew J.; Champouret, Nicolas; Hernández-Pinzón, Inmaculada; Ward, Eric R.; Wulff, Brande B. H.

    2013-01-01

    Aegilopssharonensis Eig (Sharon goatgrass) is a wild diploid relative of wheat within the Sitopsis section of Aegilops. This species represents an untapped reservoir of genetic diversity for traits of agronomic importance, especially as a source of novel disease resistance. To gain a foothold in this genetic resource, we sequenced the cDNA from leaf tissue of two geographically distinct Ae. sharonensis accessions (1644 and 2232) using the 454 Life Sciences platform. We compared the results of two different assembly programs using different parameter sets to generate 13 distinct assemblies in an attempt to maximize representation of the gene space in de novo transcriptome assembly. The most sensitive assembly (71,029 contigs; N50 674 nts) retrieved 18,684 unique best reciprocal BLAST hits (BRBH) against six previously characterised grass proteomes while the most specific assembly (30,609 contigs; N50 815 nts) retrieved 15,687 BRBH. We combined these two assemblies into a set of 62,243 non-redundant sequences and identified 139 belonging to plant disease resistance genes of the nucleotide binding leucine-rich repeat class. Based on the non-redundant sequences, we predicted 37,743 single nucleotide polymorphisms (SNP), equivalent to one per 1,142 bp. We estimated the level of heterozygosity as 1.6% in accession 1644 and 30.1% in 2232. The Ae. sharonensis leaf transcriptome provides a rich source of sequence and SNPs for this wild wheat relative. These sequences can be used with existing monocot genome sequences and EST sequence collections (e.g. barley, Brachypodium, wheat, rice, maize and Sorghum) to assist with genetic and physical mapping and candidate gene identification in Ae. sharonensis. These resources provide an initial framework to further build on and characterise the genetic and genomic structure of Ae. sharonensis. PMID:23951332

  1. Variation and geographical distribution of the genotypes controlling the diagnostic spike morphology of two varieties of Aegilops caudata l.

    PubMed

    Ohta, S

    2001-10-01

    Aegilops caudata L. is an annual wild relative of wheat distributed over the northeastern Mediterranean basin. It consists of two taxonomic varieties, var. typica with awnless lateral spikelets and var.polyathera with awned lateral spikelets. To clarify the variation and the geographical distribution of the genotypes controlling the diagnostic spike morphology of the two taxonomic varieties, three crossing experiments were carried out. First, two varieties collected from nine sympatric populations in the Aegean islands were crossed reciprocally. All of the F1 hybrids were var. typica and the segregation ratio in the F2 generation was 3 typica: 1 polyathera. Secondly, 13 typica accessions collected from the entire distribution area of the variety were crossed with a common polyathera accession. The F1 hybrids involving eight typica accessions from Greece and West Anatolia were var. typica, while those involving five typica accessions from East Anatolia, Syria and Iraq were var. polyathera. Thirdly, the typica F1 hybrids between the Aegean and the Syrian typica accessions were backcrossed to the latter. Four of the seven BC1F1 plants obtained were var. typica, but the other three were var. polyathera. Based on these results, the following two conclusions were made. First, the awnless lateral spikelets characteristic of var. typica are due to two different genotypes: one is a dominant allele suppressing awn development on lateral spikelets and the other is a recessive allele(s) for awnless lateral spikelets with no dominant suppressor allele. Secondly, the former genotype occurs only in the western region of the distribution area of the species, while the latter occurs in the eastern region. The present results and the recent palaeopalynological evidence also suggested that var. polyathera, with more awns than var. typica, rapidly colonized Central Anatolia from the Levant or East Taurus/Zagros mountains arc after the last glacial period. PMID:11817646

  2. Potential Implications of Climate Change on Aegilops Species Distribution: Sympatry of These Crop Wild Relatives with the Major European Crop Triticum aestivum and Conservation Issues

    PubMed Central

    Prosperi, Jean-Marie; David, Jacques

    2016-01-01

    Gene flow from crop to wild relatives is a common phenomenon which can lead to reduced adaptation of the wild relatives to natural ecosystems and/or increased adaptation to agrosystems (weediness). With global warming, wild relative distributions will likely change, thus modifying the width and/or location of co-occurrence zones where crop-wild hybridization events could occur (sympatry). This study investigates current and 2050 projected changes in sympatry levels between cultivated wheat and six of the most common Aegilops species in Europe. Projections were generated using MaxEnt on presence-only data, bioclimatic variables, and considering two migration hypotheses and two 2050 climate scenarios (RCP4.5 and RCP8.5). Overall, a general decline in suitable climatic conditions for Aegilops species outside the European zone and a parallel increase in Europe were predicted. If no migration could occur, the decline was predicted to be more acute outside than within the European zone. The potential sympatry level in Europe by 2050 was predicted to increase at a higher rate than species richness, and most expansions were predicted to occur in three countries, which are currently among the top four wheat producers in Europe: Russia, France and Ukraine. The results are also discussed with regard to conservation issues of these crop wild relatives. PMID:27100790

  3. [Detection of the introgression of genome elements of the Aegilops cylindrica host. into the Triticum aestivum L. genome by ISSR and SSR analysis].

    PubMed

    Galaev, A V; Babaiants, L T; Sivolap, Iu M

    2004-12-01

    To reveal sites of the donor genome in wheat crossed with Aegilops cylindrica, which acquired conferred resistance to fungal diseases, a comparative analysis of introgressive and parental forms was conducted. Two systems of PCR analysis, ISSR and SSR-PCR, were employed. Upon use of 7 ISSR primers in genotypes of 30 individual plants BC1 F9 belonging to lines 5/55-91 and 5/20-91, 19 ISSR loci were revealed and assigned to introgressive fragments of Aegilops cylindrica genome in Triticum aestivum. The 40 pairs of SSR primers allowed the detection of seven introgressive alleles; three of these alleles were located on common wheat chromosomes in the B genome, while four alleles, in the D genome. Based on data of microsatellite analysis, it was assumed that the telomeric region of the long arm of common wheat chromosome 6A also changed. ISSR and SSR methods were shown to be effective for detecting variability caused by introgression of foreign genetic material into the genome of common wheat. PMID:15648148

  4. Assessment of genomic and species relationships in Triticum and Aegilops by PAGE and by differential staining of seed albumins and globulins.

    PubMed

    Caldwell, K A; Kasarda, D D

    1978-11-01

    Endosperm protein components from common bread wheats (Triticum aestivum L.) and related species were extracted with aluminum lactate, pH 3.2, and examined by electrophoresis in the same buffer. Electrophoretic patterns of the albumins and globulins were compared to evaluate the possibility that a particular species might have contributed its genome to tetraploid or hexaploid wheat. Together with protein component mobilities, differential band staining with Coomassie Brilliant Blue R250 was employed to test the identity or non-identity of bands. Eight species and 63 accessions, representative of Triticum and Aegilops were tested. Considerable intraspecific variation was observed for patterns of diploid but not for tetraploid or hexaploid species. Patterns of some accessions of Triticum urartu agreed closely with major parts of the patterns of Triticum dicoccoides and T. aestivum. A fast-moving, green band was found in all accessions of T. urartu and of Triticum boeoticum, however, that was not found in those of T. dicoccoides or T. aestivum. This band was present in all accessions of Triticum araraticum and Triticum zhukovskyi. Patterns of Aegilops longissima, which has been suggested as the donor of the B genome, differed substantially from those of T. dicoccoides and T. aestivum. Finally, two marker proteins of intermediate mobility were also observed and may be used to discriminate between accessions of T. araraticum/T. zhukovskyi and those of T. dicoccoides/T. aestivum. PMID:24317663

  5. Potential Implications of Climate Change on Aegilops Species Distribution: Sympatry of These Crop Wild Relatives with the Major European Crop Triticum aestivum and Conservation Issues.

    PubMed

    Ostrowski, Marie-France; Prosperi, Jean-Marie; David, Jacques

    2016-01-01

    Gene flow from crop to wild relatives is a common phenomenon which can lead to reduced adaptation of the wild relatives to natural ecosystems and/or increased adaptation to agrosystems (weediness). With global warming, wild relative distributions will likely change, thus modifying the width and/or location of co-occurrence zones where crop-wild hybridization events could occur (sympatry). This study investigates current and 2050 projected changes in sympatry levels between cultivated wheat and six of the most common Aegilops species in Europe. Projections were generated using MaxEnt on presence-only data, bioclimatic variables, and considering two migration hypotheses and two 2050 climate scenarios (RCP4.5 and RCP8.5). Overall, a general decline in suitable climatic conditions for Aegilops species outside the European zone and a parallel increase in Europe were predicted. If no migration could occur, the decline was predicted to be more acute outside than within the European zone. The potential sympatry level in Europe by 2050 was predicted to increase at a higher rate than species richness, and most expansions were predicted to occur in three countries, which are currently among the top four wheat producers in Europe: Russia, France and Ukraine. The results are also discussed with regard to conservation issues of these crop wild relatives. PMID:27100790

  6. Genetic variation of jointed goatgrass (Aegilops cylindrica Host.) from Iran using RAPD-PCR and SDS-PAGE of seed proteins.

    PubMed

    Farkhari, M; Naghavi, M R; Pyghambari, S A; Sabokdast

    2007-09-01

    Genetic variation of 28 populations of jointed goatgrass (Aegilops cylindrica Host.), collected from different parts of Iran, were evaluated using both RAPD-PCR and SDS-PAGE of seed proteins. The diversity within and between populations for the three-band High Molecular Weight (HMW) subunits of glutenin pattern were extremely low. Out of 15 screened primers of RAPD, 14 primers generated 133 reproducible fragments which among them 92 fragments were polymorphic (69%). Genetic similarity calculated from the RAPD data ranged from 0.64 to 0.98. A dendrogram was prepared on the basis of a similarity matrix using the UPGMA algorithm and separated the 28 populations into two groups. Confusion can happen between populations with the same origin as well as between populations of very diverse geographical origins. Our results show that compare to seed storage protein, RAPD is suitable for genetic diversity assessment in Ae. cylindrica populations. PMID:19090190

  7. A comparative analysis of chromosome pairing at metaphase I in interspecific hybrids between durum wheat (Triticum turgidum L.) and the most widespread Aegilops species.

    PubMed

    Cifuentes, M; Garcia-Agüero, V; Benavente, E

    2010-07-01

    Homoeologous metaphase I (MI) associations in hybrids between durum wheat and its wild allotetraploid relatives Aegilops neglecta, Ae. triuncialis and Ae. ventricosa have been characterized by a genomic in situ hybridization procedure that allows simultaneous discrimination of A, B and wild species genomes. Earlier results in equivalent hybrids with the wild species Ae. cylindrica and Ae. geniculata have also been considered to comparatively assay the MI pairing pattern of the durum wheat x Aegilops interspecific combinations more likely to occur in nature. The general picture can be drawn as follows. A and B wheat genomes pair with each other less than the 2 wild constituent genomes do in any of the hybrid combinations examined. Interspecific wheat-wild associations account for 60-70% of total MI pairing in all hybrids, except in that derived from Ae. triuncialis, but the A genome is always the wheat partner most frequently involved in MI pairing with the wild homoeologues. Hybrids with Ae. cylindrica, Ae. geniculata and Ae. ventricosa showed similar reduced levels of MI association and virtually identical MI pairing patterns. However, certain recurrent differences were found when the pattern of homoeologous pairing of hybrids from either Ae. triuncialis or Ae. neglecta was contrasted to that observed in the other durum wheat hybrid combinations. In the former case, a remarkable preferential pairing between the wild species constituent genomes U(t) and C(t) seems to be the reason, whereas a general promotion of homoeologous pairing, qualitatively similar to that observed under the effect of the ph1c mutation, appears to occur in the hybrid with Ae. neglecta. It is further discussed whether the results reported here can be extrapolated to the corresponding bread wheat hybrid combinations. PMID:20551603

  8. Discovery and molecular mapping of a new gene conferring resistance to stem rust, Sr53, derived from Aegilops geniculata and characterization of spontaneous translocation stocks with reduced alien chromatin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study reports the discovery and molecular mapping of a resistance gene effective against stem rust races RKQQC and TTKSK (Ug99) derived from Aegilops geniculata (2n=4x=28, UgUgMgMg). Two populations from the crosses TA5599 (T5DL-5MgL.5MgS)/TA3809 (ph1b mutant in Chinese Spring background) and T...

  9. Visualization of A- and B-genome chromosomes in wheat (Triticum aestivum L.) x jointed goatgrass (Aegilops cylindrica Host) backcross progenies.

    PubMed

    Wang, Z N; Hang, A; Hansen, J; Burton, C; Mallory-Smith, C A; Zemetra, R S

    2000-12-01

    Wheat (Triticum aestivum) and jointed goatgrass (Aegilops cylindrica) can cross with each other, and their self-fertile backcross progenies frequently have extra chromosomes and chromosome segments, presumably retained from wheat, raising the possibility that a herbicide resistance gene might transfer from wheat to jointed goatgrass. Genomic in situ hybridization (GISH) was used to clarify the origin of these extra chromosomes. By using T. durum DNA (AABB genome) as a probe and jointed goatgrass DNA (CCDD genome) as blocking DNA, one, two, and three A- or B-genome chromosomes were identified in three BC2S2 individuals where 2n = 29, 30, and 31 chromosomes, respectively. A translocation between wheat and jointed goatgrass chromosomes was also detected in an individual with 30 chromosomes. In pollen mother cells with meiotic configuration of 14 II + 2 I, the two univalents were identified as being retained from the A or B genome of wheat. By using Ae. markgrafii DNA (CC genome) as a probe and wheat DNA (AABBDD genome) as blocking DNA. 14 C-genome chromosomes were visualized in all BC2S2 individuals. The GISH procedure provides a powerful tool to detect the A or B-genome chromatin in a jointed goatgrass background, making it possible to assess the risk of transfer of herbicide resistance genes located on the A or B genome of wheat to jointed goatgrass. PMID:11195336

  10. Complete characterization of wheat-alien metaphase I pairing in interspecific hybrids between durum wheat (Triticum turgidum L.) and jointed goatgrass (Aegilops cylindrica Host).

    PubMed

    Cifuentes, Marta; Benavente, Elena

    2009-05-01

    The pattern of homoeologous metaphase I (MI) pairing has been fully characterized in durum wheat x Aegilops cylindrica hybrids (2n = 4x = 28, ABC(c)D(c)) by an in situ hybridization procedure that has permitted individual discrimination of every wheat and wild constituent genome. One of the three hybrid genotypes examined carried the ph1c mutation. In all cases, MI associations between chromosomes of both species represented around two-third of total. Main results from the analysis are as follows (a) the A genome chromosomes are involved in wheat-wild MI pairing more frequently than the B genome partners, irrespective of the alien genome considered; (b) both durum wheat genomes pair preferentially with the D(c) genome of jointed goatgrass. These findings are discussed in relation to the potential of genetic transference between wheat crops and this weedy relative. It can also be highlighted that inactivation of Ph1 provoked a relatively higher promotion of MI associations involving B genome. PMID:19319503

  11. Inducing rye 1R chromosome structural changes in common wheat cv. Chinese spring by the gametocidal chromosome 2C of Aegilops cylindrica.

    PubMed

    Shi, Fang; Liu, Kun-Fan; Endo, Takashi R; Wang, Dao-Wen

    2005-05-01

    To generate 1 R deletion and translocation lines, we introduced a 2C chromosome,which was derived from Aegilops cylindrica and was known to have a gametocidal function when added monosomically into common wheat cv. Chinese Spring (CS) and its derivative, into a wheat-rye 1R chromosome disomic addition line (CS-1R"). When the individuals with chromosome constitution 21" + 1R" + 2C' (2n = 45) were selfed, the 1R chromosome structural changes were found to be induced with high frequency (24.1%) among the progenies. By using C-banding and GISH analysis, we analyzed 1R structural changes in 46 F3 individuals, which came from 23 F2 plants. The rearranged 1R chromosomes could be characterized in about 85% of the F3 individuals. This included telosome 1RL (39.1%), iso-chromosome 1 RL (2.2%), whole arm translocation involving 1RL (32.6%), telosome 1RS (4.3%), iso-chromosome 1RS (4.3%), and 1R deletion mutant with break point in the long arm (2.2%). The mutant 1R lines obtained in this study will potentially be useful in mapping the chromosome locations of agronomically important genes located in 1R. This study also demonstrated that molecular markers might be used to identify wheat chromosome arm involved in translocation with 1R. PMID:16018259

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

    PubMed

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

    2015-02-01

    We aim to improve diversity of domesticated wheat by transferring genetic variation for important target traits from related wild and cultivated grass species. The present study describes the development of F1 hybrids between wheat and related species from the genera Aegilops, Secale, Thinopyrum, and Triticum and production of new amphidiploids. Amphidiploid lines were produced from 20 different distant relatives. Both colchicine and caffeine were successfully used to double the chromosome numbers. The genomic constitution of the newly formed amphidiploids derived from seven distant relatives was determined using genomic in situ hybridization (GISH). Altogether, 42 different plants were analysed, 19 using multicolour GISH separating the chromosomes from the A, B, and D genomes of wheat, as well as the distant relative, and 23 using single colour GISH. Restructuring of the allopolyploid genome, both chromosome losses and aneuploidy, was detected in all the genomes contained by the amphidiploids. From the observed chromosome numbers there is an indication that in amphidiploids the B genome of wheat suffers chromosome losses less frequently than the other wheat genomes. Phenotyping to realize the full potential of the wheat-related grass germplasm is underway, linking the analyzed genotypes to agronomically important target traits. PMID:26053312

  13. Exploring the tertiary gene pool of bread wheat: sequence assembly and analysis of chromosome 5M(g) of Aegilops geniculata.

    PubMed

    Tiwari, Vijay K; Wang, Shichen; Danilova, Tatiana; Koo, Dal Hoe; Vrána, Jan; Kubaláková, Marie; Hribova, Eva; Rawat, Nidhi; Kalia, Bhanu; Singh, Narinder; Friebe, Bernd; Doležel, Jaroslav; Akhunov, Eduard; Poland, Jesse; Sabir, Jamal S M; Gill, Bikram S

    2015-11-01

    Next-generation sequencing (NGS) provides a powerful tool for the discovery of important genes and alleles in crop plants and their wild relatives. Despite great advances in NGS technologies, whole-genome shotgun sequencing is cost-prohibitive for species with complex genomes. An attractive option is to reduce genome complexity to a single chromosome prior to sequencing. This work describes a strategy for studying the genomes of distant wild relatives of wheat by isolating single chromosomes from addition or substitution lines, followed by chromosome sorting using flow cytometry and sequencing of chromosomal DNA by NGS technology. We flow-sorted chromosome 5M(g) from a wheat/Aegilops geniculata disomic substitution line [DS5M(g) (5D)] and sequenced it using an Illumina HiSeq 2000 system at approximately 50 × coverage. Paired-end sequences were assembled and used for structural and functional annotation. A total of 4236 genes were annotated on 5M(g) , in close agreement with the predicted number of genes on wheat chromosome 5D (4286). Single-gene FISH indicated no major chromosomal rearrangements between chromosomes 5M(g) and 5D. Comparing chromosome 5M(g) with model grass genomes identified synteny blocks in Brachypodium distachyon, rice (Oryza sativa), sorghum (Sorghum bicolor) and barley (Hordeum vulgare). Chromosome 5M(g) -specific SNPs and cytogenetic probe-based resources were developed and validated. Deletion bin-mapped and ordered 5M(g) SNP markers will be useful to track 5M-specific introgressions and translocations. This study provides a detailed sequence-based analysis of the composition of a chromosome from a distant wild relative of bread wheat, and opens up opportunities to develop genomic resources for wild germplasm to facilitate crop improvement. PMID:26408103

  14. Two Homoeologous Wheat Genes Confer Sensitivity to a Single Host-Selective Toxin and Susceptibility to Stagonospora nodorum blotch (SNB)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pathogen Stagonospora nodorum produces multiple host-selective toxins that interact with corresponding wheat sensitivity genes in an inverse gene-for-gene manner to cause the disease Stagonospora nodorum blotch (SNB) in wheat. Here, we screened accessions of Aegilops tauschii, the D-genome donor...

  15. Map-based analysis of the tenacious glume gene Tg-B1 of wild emmer and its role in wheat domestication

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The domestication of wheat was instrumental in spawning the civilization of humankind, and it occurred through genetic mutations that gave rise to types with non-fragile rachises, soft glumes, and free-threshing seed. The Tg-D1 gene on chromosome 2D of Aegilops tauschii, the D-genome progenitor of ...

  16. Genome Comparisons Reveal a Dominant Mechanism of Chromosome Number Reduction in Grasses and Accelerated Genome Evolution in Triticeae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Single nucleotide polymorphism was employed in the construction of a high-resolution, expressed sequence tag (EST) map of Aegilops tauschii, the diploid source of the wheat D genome. Comparison of the map with the rice and sorghum genome sequences revealed 50 inversions and translocations; 2, 8, and...

  17. Saturation Mapping of Hessian Fly Resistance Gene H26 in Synthetic Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hessian fly (Mayetiola destructor) resistance gene H26, derived from Aegilops tauschii, is one of the most effective R genes against various biotypes of Hessian fly. Using a limited number of PCR-based molecular markers, a previous study mapped H26 to the chromosomal deletion bin 3DL3-0.81-1.00. The...

  18. Genetic Variation of Seed Dormancy in Synthetic Hexaploid Wheat-Derived Populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aegilops tauschii, the D-genome donor of wheat (Triticum aestivum), has very strong seed dormancy and genes controlling the trait may be used in breeding programs to manipulate germinability of improved cultivars. Thus, this research was conducted to initiate a project to identify dormancy genes fro...

  19. Identification and mapping of QTLs for FHB resistance in a synthetic hexaploid wheat line

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The synthetic hexaploid wheat (SHW) lines derived from crosses between tetraploid wheat (AABB genome) and Aegilops tauschii (D genome) possess resistance to various diseases including Fusarium head blight (FHB). However, the genetics of FHB resistance in these synthetic lines is poorly understood. B...

  20. Molecular and genetic characterization of Hessian fly-resistance genes in synthetic hexaploid wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Synthetic hexaploid wheat (SHW), derived from crosses between tetraploid wheat (Triticum turgidum) and Aegilops tauschii, has proven to be an excellent source of resistance genes for various diseases and pests in wheat (T. aestivum). We previously evaluated a large collection of SHW lines for resis...

  1. 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...

  2. A Candidate Gene for Aphid Resistance in Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The greenbug, Schizaphis graminum (Rondani), is an important aphid pest of small grain crops in many parts of the world. A single dominant gene, Gb3 originated from Aegilops tauschii has shown consistent and durable resistance against prevailing greenbug biotypes in wheat fields. Previously, we mapp...

  3. Cloning and function validation of a nb-arc-lrr-type candidate gene for the greenbug aphid resistance locus, Gb3, in wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The greenbug, Schizaphis graminum, is one of the most important aphid pests of small grain crops in many parts of the world. A single dominant gene, Gb3 originated from Aegilops tauschii has shown consistent and durable resistance against prevailing greenbug biotypes in wheat fields. A fine genetic ...

  4. RNA-Seq Based Identification of Candidate Parasitism Genes of Cereal Cyst Nematode (Heterodera avenae) during Incompatible Infection to Aegilops variabilis.

    PubMed

    Zheng, Minghui; Long, Hai; Zhao, Yun; Li, Lin; Xu, Delin; Zhang, Haili; Liu, Feng; Deng, Guangbing; Pan, Zhifen; Yu, Maoqun

    2015-01-01

    One of the reasons for the progressive yield decline observed in cereals production is the rapid build-up of populations of the cereal cyst nematode (CCN, Heterodera avenae). These nematodes secrete so-call effectors into their host plant to suppress the plant defense responses, alter plant signaling pathways and then induce the formation of syncytium after infection. However, little is known about its molecular mechanism and parasitism during incompatible infection. To gain insight into its repertoire of parasitism genes, we investigated the transcriptome of the early parasitic second-stage (30 hours, 3 days and 9 days post infection) juveniles of the CCN as well as the CCN infected tissue of the host Aegilops variabilis by Illumina sequencing. Among all assembled unigenes, 681 putative genes of parasitic nematode were found, in which 56 putative effectors were identified, including novel pioneer genes and genes corresponding to previously reported effectors. All the 681 CCN unigenes were mapped to 229 GO terms and 200 KEGG pathways, including growth, development and several stimulus-related signaling pathways. Sixteen clusters were involved in the CCN unigene expression atlas at the early stages during infection process, and three of which were significantly gene-enriched. Besides, the protein-protein interaction network analysis revealed 35 node unigenes which may play an important role in the plant-CCN interaction. Moreover, in a comparison of differentially expressed genes between the pre-parasitic juveniles and the early parasitic juveniles, we found that hydrolase activity was up-regulated in pre J2s whereas binding activity was upregulated in infective J2s. RT-qPCR analysis on some selected genes showed detectable expression, indicating possible secretion of the proteins and putative role in infection. This study provided better insights into the incompatible interaction between H. avenae and the host plant Ae. varabilis. Moreover, RNAi targets with

  5. RNA-Seq Based Identification of Candidate Parasitism Genes of Cereal Cyst Nematode (Heterodera avenae) during Incompatible Infection to Aegilops variabilis

    PubMed Central

    Zheng, Minghui; Long, Hai; Zhao, Yun; Li, Lin; Xu, Delin; Zhang, Haili; Liu, Feng; Deng, Guangbing; Pan, Zhifen; Yu, Maoqun

    2015-01-01

    One of the reasons for the progressive yield decline observed in cereals production is the rapid build-up of populations of the cereal cyst nematode (CCN, Heterodera avenae). These nematodes secrete so-call effectors into their host plant to suppress the plant defense responses, alter plant signaling pathways and then induce the formation of syncytium after infection. However, little is known about its molecular mechanism and parasitism during incompatible infection. To gain insight into its repertoire of parasitism genes, we investigated the transcriptome of the early parasitic second-stage (30 hours, 3 days and 9 days post infection) juveniles of the CCN as well as the CCN infected tissue of the host Aegilops variabilis by Illumina sequencing. Among all assembled unigenes, 681 putative genes of parasitic nematode were found, in which 56 putative effectors were identified, including novel pioneer genes and genes corresponding to previously reported effectors. All the 681 CCN unigenes were mapped to 229 GO terms and 200 KEGG pathways, including growth, development and several stimulus-related signaling pathways. Sixteen clusters were involved in the CCN unigene expression atlas at the early stages during infection process, and three of which were significantly gene-enriched. Besides, the protein-protein interaction network analysis revealed 35 node unigenes which may play an important role in the plant-CCN interaction. Moreover, in a comparison of differentially expressed genes between the pre-parasitic juveniles and the early parasitic juveniles, we found that hydrolase activity was up-regulated in pre J2s whereas binding activity was upregulated in infective J2s. RT-qPCR analysis on some selected genes showed detectable expression, indicating possible secretion of the proteins and putative role in infection. This study provided better insights into the incompatible interaction between H. avenae and the host plant Ae. varabilis. Moreover, RNAi targets with

  6. The Molecular Basis of Genetic Diversity among Cytoplasms of TRITICUM and AEGILOPS Species. II. on the Origin of Polyploid Wheat Cytoplasms as Suggested by Chloroplast DNA Restriction Fragment Patterns.

    PubMed

    Tsunewaki, K; Ogihara, Y

    1983-05-01

    In attempts to identify the phylogenetic donors of cytoplasm to Emmer-Dinkel and Timopheevi groups of wheat (Triticum), and the Aegilops kotschyi-Ae. variabilis complex, the restriction fragment patterns of chloroplast DNAs of representative species were compared with those of their putative diploid ancestors. The following seven restriction enzymes were used; BamHI, EcoRI, HindIII, KpnI, PstI, SmaI and XhoI. The restriction fragment patterns of an Emmer and a Dinkel (common) wheat were identical with those of Ae. longissima , and different from those of Ae. aucheri, Ae. bicornis, Ae. searsii, Ae. sharonensis, Ae. speltoides, and T. urartu by 4 to 12 fragments. The restriction fragment patterns of a Timopheevi wheat were identical with those of Ae. aucheri, and different from those of all other diploids by four to nine fragments. The restriction fragment patterns of Ae. variabilis were identical to those of Ae. bicornis and Ae. searsii , and different from those of all other species. Thus, we have concluded that Ae. longissima, Ae. aucheri and Ae. bicornis (or Ae. searsii) were the cytoplasm donors to the Emmer-Dinkel and the Timopheevi groups, and the Ae. kotschyi-Ae. variabilis complex, respectively. A diphyletic origin of Emmer and Timopheevi groups is supported by the present results. PMID:17246126

  7. Sequence polymorphism in polyploid wheat and their d-genome diploid ancestor.

    PubMed

    Caldwell, Katherine S; Dvorak, Jan; Lagudah, Evans S; Akhunov, Eduard; Luo, Ming-Cheng; Wolters, Petra; Powell, Wayne

    2004-06-01

    Sequencing was used to investigate the origin of the D genome of the allopolyploid species Triticum aestivum and Aegilops cylindrica. A 247-bp region of the wheat D-genome Xwye838 locus, encoding ADP-glucopyrophosphorylase, and a 326-bp region of the wheat D-genome Gss locus, encoding granule-bound starch synthase, were sequenced in a total 564 lines of hexaploid wheat (T. aestivum, genome AABBDD) involving all its subspecies and 203 lines of Aegilops tauschii, the diploid source of the wheat D genome. In Ae. tauschii, two SNP variants were detected at the Xwye838 locus and 11 haplotypes at the Gss locus. Two haplotypes with contrasting frequencies were found at each locus in wheat. Both wheat Xwye838 variants, but only one of the Gss haplotypes seen in wheat, were found among the Ae. tauschii lines. The other wheat Gss haplotype was not found in either Ae. tauschii or 70 lines of tetraploid Ae. cylindrica (genomes CCDD), which is known to hybridize with wheat. It is concluded that both T. aestivum and Ae. cylindrica originated recurrently, with at least two genetically distinct progenitors contributing to the formation of the D genome in both species. PMID:15238542

  8. Genome comparisons reveal a dominant mechanism of chromosome number reduction in grasses and accelerated genome evolution in Triticeae

    PubMed Central

    Luo, M. C.; Deal, K. R.; Akhunov, E. D.; Akhunova, A. R.; Anderson, O. D.; Anderson, J. A.; Blake, N.; Clegg, M. T.; Coleman-Derr, D.; Conley, E. J.; Crossman, C. C.; Dubcovsky, J.; Gill, B. S.; Gu, Y. Q.; Hadam, J.; Heo, H. Y.; Huo, N.; Lazo, G.; Ma, Y.; Matthews, D. E.; McGuire, P. E.; Morrell, P. L.; Qualset, C. O.; Renfro, J.; Tabanao, D.; Talbert, L. E.; Tian, C.; Toleno, D. M.; Warburton, M. L.; You, F. M.; Zhang, W.; Dvorak, J.

    2009-01-01

    Single-nucleotide polymorphism was used in the construction of an expressed sequence tag map of Aegilops tauschii, the diploid source of the wheat D genome. Comparisons of the map with the rice and sorghum genome sequences revealed 50 inversions and translocations; 2, 8, and 40 were assigned respectively to the rice, sorghum, and Ae. tauschii lineages, showing greatly accelerated genome evolution in the large Triticeae genomes. The reduction of the basic chromosome number from 12 to 7 in the Triticeae has taken place by a process during which an entire chromosome is inserted by its telomeres into a break in the centromeric region of another chromosome. The original centromere–telomere polarity of the chromosome arms is maintained in the new chromosome. An intrachromosomal telomere–telomere fusion resulting in a pericentric translocation of a chromosome segment or an entire arm accompanied or preceded the chromosome insertion in some instances. Insertional dysploidy has been recorded in three grass subfamilies and appears to be the dominant mechanism of basic chromosome number reduction in grasses. A total of 64% and 66% of Ae. tauschii genes were syntenic with sorghum and rice genes, respectively. Synteny was reduced in the vicinity of the termini of modern Ae. tauschii chromosomes but not in the vicinity of the ancient termini embedded in the Ae. tauschii chromosomes, suggesting that the dependence of synteny erosion on gene location along the centromere–telomere axis either evolved recently in the Triticeae phylogenetic lineage or its evolution was recently accelerated. PMID:19717446

  9. The gene Sr33, an ortholog of barley Mla genes, encodes resistance to wheat stem rust race Ug99.

    PubMed

    Periyannan, Sambasivam; Moore, John; Ayliffe, Michael; Bansal, Urmil; Wang, Xiaojing; Huang, Li; Deal, Karin; Luo, Mingcheng; Kong, Xiuying; Bariana, Harbans; Mago, Rohit; McIntosh, Robert; Dodds, Peter; Dvorak, Jan; Lagudah, Evans

    2013-08-16

    Wheat stem rust, caused by the fungus Puccinia graminis f. sp. tritici, afflicts bread wheat (Triticum aestivum). New virulent races collectively referred to as "Ug99" have emerged, which threaten global wheat production. The wheat gene Sr33, introgressed from the wild relative Aegilops tauschii into bread wheat, confers resistance to diverse stem rust races, including the Ug99 race group. We cloned Sr33, which encodes a coiled-coil, nucleotide-binding, leucine-rich repeat protein. Sr33 is orthologous to the barley (Hordeum vulgare) Mla mildew resistance genes that confer resistance to Blumeria graminis f. sp. hordei. The wheat Sr33 gene functions independently of RAR1, SGT1, and HSP90 chaperones. Haplotype analysis from diverse collections of Ae. tauschii placed the origin of Sr33 resistance near the southern coast of the Caspian Sea. PMID:23811228

  10. [Molecular cytogenetic identification of Aegilops ventricosa x Aegilops cylindrica amphiploid SDAU18].

    PubMed

    Wang, Yu Hai; Bao, Yin Guang; Hao, Yuan Feng; Yuan, Yuan Yuan; Zhao, Chun Hua; Wang, Qing Zhuan; Wang, Hong Gang

    2009-02-01

    SDAU18, an amphiploid of Ae.ventricosa with Ae.cylindrica, was identified by cytological analysis, seed storage protein electrophoresis, genomic in situ hybridization (GISH) and inoculation assessment. The results are as follows: The chromosome number of root tip cells (RTCs) of SDAU18 plants varied from 52 to 56. 28 bivalents were observed in most PMCs MI of SDAU18 with 56 chromosomes, meanwhile, a few univalents, multivalents also existed in some PMCs MI, and the average chromosome configuration was 2n = 56 = 3.21 I +19.78 II, (Ring)+6.50 II (Rod)+0.01 III +0.04 IV (Ring)R+0.01 IV (Rod). There were both Ae. ventricosa-specific bands and Ae. cylindrica-specific bands in the seed storage protein electrophoretogram of SDAU18, furthermore, SDAU18 had one novel HMW-GS not found in the parents and two novel ones not found in common wheats. By labeling the total genomic DNA of Ae. ventricosa and Ae. cylindrica as probes respectively, and using that of another parent as block, GISH of RTCs spread of SDAU18 was carried out. The green hybridization signal was observed in 14 chromosomes respectively, within 56 ones in RTCs of SDAU18. SDAU18 was immune to powdery mildew and stripe rusts. SDAU18 was an amphiploid of Ae. ventricosa with Ae. cylindrica, and had very important significance in wheat breeding and genetic improvement. PMID:19306684

  11. Characterization and expression analysis of WOX5 genes from wheat and its relatives.

    PubMed

    Zhao, Shan; Jiang, Qian-Tao; Ma, Jian; Zhang, Xiao-Wei; Zhao, Quan-Zhi; Wang, Xiu-Ying; Wang, Chang-Shui; Cao, Xue; Lu, Zhen-Xiang; Zheng, You-Liang; Wei, Yu-Ming

    2014-03-01

    The WUSCHEL (WUS)-related homeobox (WOX) gene family plays an important role in coordinating gene transcription in the early phases of embryogenesis. In this study, we isolated and characterized WOX5 from common wheat and its relatives Triticum monococcum, Triticum urartu, Aegilops speltoides, Aegilops searsii, Aegilops sharonensis, Aegilops longissima, Aegilops bicornis, Aegilops tauschii, and Triticum turgidum. The size of the characterized WOX5 alleles ranged from 1029 to 1038 bp and encompassed the complete open reading frame (ORF) as well as 5' upstream and 3' downstream sequences. Domain prediction analysis showed that the putative primary structures of wheat WOX5 protein include the highly conserved homeodomain besides the WUS-box domain and the EAR-like domain, which is/are present in some members of the WOX protein family. The full-length ORF was subcloned into a prokaryotic expression vector pET30a, and an approximate 26-kDa protein was successfully expressed in Escherichia coli BL21 (DE3) cells with IPTG induction. The WOX5 genes from wheat-related species exhibit a similar structure to and high sequence similarity with WOX5 genes from common wheat. The degree of divergence and phylogenetic tree analysis among WOX5 alleles suggested the existence of three homoeologous copies in the A, B, or D genome of common wheat. Quantitative PCR results showed that TaWOX5 was primarily expressed in the root and calli induced by auxin and cytokinin, indicating that TaWOX5 may play a role related to root formation or development and is associated with hormone regulation in somatic embryogenesis. PMID:24368329

  12. The chloroplast view of the evolution of polyploid wheat.

    PubMed

    Gornicki, Piotr; Zhu, Huilan; Wang, Junwei; Challa, Ghana S; Zhang, Zhengzhi; Gill, Bikram S; Li, Wanlong

    2014-11-01

    Polyploid wheats comprise four species: Triticum turgidum (AABB genomes) and T. aestivum (AABBDD) in the Emmer lineage, and T. timopheevii (AAGG) and T. zhukovskyi (AAGGA(m) A(m) ) in the Timopheevi lineage. Genetic relationships between chloroplast genomes were studied to trace the evolutionary history of the species. Twenty-five chloroplast genomes were sequenced, and 1127 plant accessions were genotyped, representing 13 Triticum and Aegilops species. The A. speltoides (SS genome) diverged before the divergence of T. urartu (AA), A. tauschii (DD) and the Aegilops species of the Sitopsis section. Aegilops speltoides forms a monophyletic clade with the polyploid Emmer and Timopheevi wheats, which originated within the last 0.7 and 0.4 Myr, respectively. The geographic distribution of chloroplast haplotypes of the wild tetraploid wheats and A. speltoides illustrates the possible geographic origin of the Emmer lineage in the southern Levant and the Timopheevi lineage in northern Iraq. Aegilops speltoides is the closest relative of the diploid donor of the chloroplast (cytoplasm), as well as the B and G genomes to Timopheevi and Emmer lineages. Chloroplast haplotypes were often shared by species or subspecies within major lineages and between the lineages, indicating the contribution of introgression to the evolution and domestication of polyploid wheats. PMID:25059383

  13. Phylogeny and expression of paralogous and orthologous sulphate transporter genes in diploid and hexaploid wheats.

    PubMed

    Buchner, Peter; Prosser, Ian M; Hawkesford, Malcolm J

    2004-06-01

    Twelve genes encoding two closely related subtypes (ST1.1a and ST1.1b) of a sulphate transporter have been identified in the diploid wheats Aegilops tauschii, Triticum urartu, and Aegilops speltoides, as well as the hexaploid Triticum aestivum. Based on phylogenetic comparisons with other plant sulphate transporters, the ST1.1a and 1.1b subtypes aligned with group 1 of the plant sulphate transporter gene family. The exon-intron structure was conserved within the ST1.1a or ST1.1b genes; however, substantial variability in intron sequences existed between the two types. The high overall sequence similarity indicated that ST1.1b represented a duplication of the ST1.1a gene, which must have occurred before the evolution of the ancestral diploid wheat progenitor. In contrast with the close relationship of the T. urartu and Ae. tauschii sequences to the corresponding A and D genome sequences of T. aestivum, the divergence between the Ae. speltoides sequences and the B genome sequences suggested that the B genome ST1.1a gene has been modified by recombination. Transcript analysis revealed predominant expression of the ST1.1a type and an influence of sulphur availability on the level of expression. PMID:15190370

  14. Synthetic hexaploid wheat and its utilization for wheat genetic improvement in China.

    PubMed

    Yang, Wuyun; Liu, Dengcai; Li, Jun; Zhang, Lianquan; Wei, Huiting; Hu, Xiaorong; Zheng, Youliang; He, Zhouhu; Zou, Yuchun

    2009-09-01

    Synthetic hexaploid wheat (Triticum turgidumxAegilops tauschii) was created to explore for novel genes from T. turgidum and Ae. tauschii that can be used for common wheat improvement. In the present paper, research advances on the utilization of synthetic hexaploid wheat for wheat genetic improvement in China are reviewed. Over 200 synthetic hexaploid wheat (SHW) accessions from the International Maize and Wheat Improvement Centre (CIMMYT) were introduced into China since 1995. Four cultivars derived from these, Chuanmai 38, Chuanmai 42, Chuanmai 43 and Chuanmai 47, have been released in China. Of these, Chuanmai 42, with large kernels and resistance to stripe rust, had the highest average yield (>6 t/ha) among all cultivars over two years in Sichuan provincial yield trials, outyielding the commercial check cultivar Chuanmai 107 by 22.7%. Meanwhile, by either artificial chromosome doubling via colchicine treatment or spontaneous chromosome doubling via a union of unreduced gametes (2n) from T. turgidum-Ae. tauschii hybrids, new SHW lines were produced in China. Mitotic-like meiosis might be the cytological mechanism of spontaneous chromosome doubling. SHW lines with genes for spontaneous chromosome doubling may be useful for producing new SHW-alien amphidiploids and double haploid in wheat genetic improvement. PMID:19782955

  15. QTug.sau-3B Is a Major Quantitative Trait Locus for Wheat Hexaploidization

    PubMed Central

    Hao, Ming; Luo, Jiangtao; Zeng, Deying; Zhang, Li; Ning, Shunzong; Yuan, Zhongwei; Yan, Zehong; Zhang, Huaigang; Zheng, Youliang; Feuillet, Catherine; Choulet, Frédéric; Yen, Yang; Zhang, Lianquan; Liu, Dengcai

    2014-01-01

    Meiotic nonreduction resulting in unreduced gametes is thought to be the predominant mechanism underlying allopolyploid formation in plants. Until now, however, its genetic base was largely unknown. The allohexaploid crop common wheat (Triticum aestivum L.), which originated from hybrids of T. turgidum L. with Aegilops tauschii Cosson, provides a model to address this issue. Our observations of meiosis in pollen mother cells from T. turgidum×Ae. tauschii hybrids indicated that first division restitution, which exhibited prolonged cell division during meiosis I, was responsible for unreduced gamete formation. A major quantitative trait locus (QTL) for this trait, named QTug.sau-3B, was detected on chromosome 3B in two T. turgidum×Ae. tauschii haploid populations. This QTL is situated between markers Xgwm285 and Xcfp1012 and covered a genetic distance of 1 cM in one population. QTug.sau-3B is a haploid-dependent QTL because it was not detected in doubled haploid populations. Comparative genome analysis indicated that this QTL was close to Ttam-3B, a collinear homolog of tam in wheat. Although the relationship between QTug.sau-3B and Ttam requires further study, high frequencies of unreduced gametes may be related to reduced expression of Ttam in wheat. PMID:25128436

  16. Co-existence of salt and drought tolerance in Triticeae.

    PubMed

    Farooq, S; Azam, F

    2001-01-01

    Cell membrane stability (CMS) technique was used to screen for drought tolerance, salt tolerant accessions of three Aegilops species, Ae. tauschii, Ae. cylindrica, Ae. geniculata and two hexaploid wheat (Tricitum aestivum L.) cultivars comprising salt tolerant LU-26 and drought tolerant Chakwal-86. The objectives were to see how valid it is for a salt tolerant plant to be drought tolerant as well and to identify the character(s) that may contribute to drought tolerance. Three moisture levels equal to 100, 50 and 25% saturation capacity of the soil were used for plant cultivation. Injury percentage (IP) based on in-vitro desiccation induced by polyethylene glycol (PEG) in leaf tissue was measured through the conductivity of the electrolyte leakage. Injury percentage decreased in all the test material with decrease in soil moisture contents. Ae. cylindrica exhibited minimum injury at 100% soil moisture level followed by Ae. tauschii and Ae. geniculata while drought tolerant wheat cultivars exhibited the maximum. The wheat cultivar Chakwal-86 has been developed for dry areas, with low soil moisture levels, and high water potential enhances the injury percentage. Aegilops cylindrica is a salt tolerant species and can thus tolerate water deficit conditions created due to low osmotic potential. Potassium appeared to play an important role in drought tolerance which was evident from high K+ contents and low K+ leakage from Aegilops cylindrica and drought tolerant wheat cultivar Chakwal-86. It was inferred from the study that salt tolerant species might prove drought tolerant in the areas where water deficit prevails due to the ability to create low intracellular osmotic potentials. PMID:12152336

  17. Genome-wide characterization of microsatellites in Triticeae species: abundance, distribution and evolution.

    PubMed

    Deng, Pingchuan; Wang, Meng; Feng, Kewei; Cui, Licao; Tong, Wei; Song, Weining; Nie, Xiaojun

    2016-01-01

    Microsatellites are an important constituent of plant genome and distributed across entire genome. In this study, genome-wide analysis of microsatellites in 8 Triticeae species and 9 model plants revealed that microsatellite characteristics were similar among the Triticeae species. Furthermore, genome-wide microsatellite markers were designed in wheat and then used to analyze the evolutionary relationship of wheat and other Triticeae species. Results displayed that Aegilops tauschii was found to be the closest species to Triticum aestivum, followed by Triticum urartu, Triticum turgidum and Aegilops speltoides, while Triticum monococcum, Aegilops sharonensis and Hordeum vulgare showed a relatively lower PCR amplification effectivity. Additionally, a significantly higher PCR amplification effectivity was found in chromosomes at the same subgenome than its homoeologous when these markers were subjected to search against different chromosomes in wheat. After a rigorous screening process, a total of 20,666 markers showed high amplification and polymorphic potential in wheat and its relatives, which were integrated with the public available wheat markers and then anchored to the genome of wheat (CS). This study not only provided the useful resource for SSR markers development in Triticeae species, but also shed light on the evolution of polyploid wheat from the perspective of microsatellites. PMID:27561724

  18. Genome-wide characterization of microsatellites in Triticeae species: abundance, distribution and evolution

    PubMed Central

    Deng, Pingchuan; Wang, Meng; Feng, Kewei; Cui, Licao; Tong, Wei; Song, Weining; Nie, Xiaojun

    2016-01-01

    Microsatellites are an important constituent of plant genome and distributed across entire genome. In this study, genome-wide analysis of microsatellites in 8 Triticeae species and 9 model plants revealed that microsatellite characteristics were similar among the Triticeae species. Furthermore, genome-wide microsatellite markers were designed in wheat and then used to analyze the evolutionary relationship of wheat and other Triticeae species. Results displayed that Aegilops tauschii was found to be the closest species to Triticum aestivum, followed by Triticum urartu, Triticum turgidum and Aegilops speltoides, while Triticum monococcum, Aegilops sharonensis and Hordeum vulgare showed a relatively lower PCR amplification effectivity. Additionally, a significantly higher PCR amplification effectivity was found in chromosomes at the same subgenome than its homoeologous when these markers were subjected to search against different chromosomes in wheat. After a rigorous screening process, a total of 20,666 markers showed high amplification and polymorphic potential in wheat and its relatives, which were integrated with the public available wheat markers and then anchored to the genome of wheat (CS). This study not only provided the useful resource for SSR markers development in Triticeae species, but also shed light on the evolution of polyploid wheat from the perspective of microsatellites. PMID:27561724

  19. Evolution of mustard (Brassica juncea Coss) subspecies in China: evidence from the chalcone synthase gene.

    PubMed

    Chen, F B; Liu, H F; Yao, Q L; Fang, P

    2016-01-01

    To explore the phylogenetic relationship, genome donor, and evolutionary history of the polyploid mustard (Brassica juncea) from China, eighty-one sequences of the chalcone synthase gene (Chs) were analyzed in 43 individuals, including 34 B. juncea, 2 B. rapa, 1 B. nigra, 2 B. oleracea, 1 B. napus, 1 B. carinata, and 2 Raphanus sativus. A maximum likelihood analysis showed that sequences from B. juncea were separated into two well-supported groups in accordance with the A and B genomes, whereas the traditional phenotypic classification of B. juncea was not wholly supported by the molecular results. The SplitsTree analysis recognized four distinct groups of Brassicaceae, and the median-joining network analysis recognized four distinct haplotypes of Chs. The estimates of Tajima's D, Fu and Li's D, and Fu and Li's F statistic for the Chs gene in the B genome were negative, while those in the A genome were significant. The results indicated that 1) the Chs sequences revealed a high level of sequence variation in Chinese mustard, 2) both tree and reticulate evolutions existed, and artificial selection played an important role in the evolution of Chinese mustard, 3) the original parental species of Chinese mustard are B. rapa var. sinapis arvensis and B. nigra (derived from China), 4) nucleotide variation in the B genome was higher than that in the A genome, and 5) cultivated mustard evolved from wild mustard, and China is one of the primary origins of B. juncea. PMID:27173323

  20. Variation in Susceptibility to Wheat dwarf virus among Wild and Domesticated Wheat

    PubMed Central

    Nygren, Jim; Shad, Nadeem; Kvarnheden, Anders; Westerbergh, Anna

    2015-01-01

    We investigated the variation in plant response in host-pathogen interactions between wild (Aegilops spp., Triticum spp.) and domesticated wheat (Triticum spp.) and Wheat dwarf virus (WDV). The distribution of WDV and its wild host species overlaps in Western Asia in the Fertile Crescent, suggesting a coevolutionary relationship. Bread wheat originates from a natural hybridization between wild emmer wheat (carrying the A and B genomes) and the wild D genome donor Aegilops tauschii, followed by polyploidization and domestication. We studied whether the strong selection during these evolutionary processes, leading to genetic bottlenecks, may have resulted in a loss of resistance in domesticated wheat. In addition, we investigated whether putative fluctuations in intensity of selection imposed on the host-pathogen interactions have resulted in a variation in susceptibility to WDV. To test our hypotheses we evaluated eighteen wild and domesticated wheat taxa, directly or indirectly involved in wheat evolution, for traits associated with WDV disease such as leaf chlorosis, different growth traits and WDV content. The plants were exposed to viruliferous leafhoppers (Psammotettix alienus) in a greenhouse trial and evaluated at two time points. We found three different plant response patterns: i) continuous reduction in growth over time, ii) weak response at an early stage of plant development but a much stronger response at a later stage, and iii) remission of symptoms over time. Variation in susceptibility may be explained by differences in the intensity of natural selection, shaping the coevolutionary interaction between WDV and the wild relatives. However, genetic bottlenecks during wheat evolution have not had a strong impact on WDV resistance. Further, this study indicates that the variation in susceptibility may be associated with the genome type and that the ancestor Ae. tauschii may be useful as genetic resource for the improvement of WDV resistance in wheat. PMID

  1. Variation in susceptibility to Wheat dwarf virus among wild and domesticated wheat.

    PubMed

    Nygren, Jim; Shad, Nadeem; Kvarnheden, Anders; Westerbergh, Anna

    2015-01-01

    We investigated the variation in plant response in host-pathogen interactions between wild (Aegilops spp., Triticum spp.) and domesticated wheat (Triticum spp.) and Wheat dwarf virus (WDV). The distribution of WDV and its wild host species overlaps in Western Asia in the Fertile Crescent, suggesting a coevolutionary relationship. Bread wheat originates from a natural hybridization between wild emmer wheat (carrying the A and B genomes) and the wild D genome donor Aegilops tauschii, followed by polyploidization and domestication. We studied whether the strong selection during these evolutionary processes, leading to genetic bottlenecks, may have resulted in a loss of resistance in domesticated wheat. In addition, we investigated whether putative fluctuations in intensity of selection imposed on the host-pathogen interactions have resulted in a variation in susceptibility to WDV. To test our hypotheses we evaluated eighteen wild and domesticated wheat taxa, directly or indirectly involved in wheat evolution, for traits associated with WDV disease such as leaf chlorosis, different growth traits and WDV content. The plants were exposed to viruliferous leafhoppers (Psammotettix alienus) in a greenhouse trial and evaluated at two time points. We found three different plant response patterns: i) continuous reduction in growth over time, ii) weak response at an early stage of plant development but a much stronger response at a later stage, and iii) remission of symptoms over time. Variation in susceptibility may be explained by differences in the intensity of natural selection, shaping the coevolutionary interaction between WDV and the wild relatives. However, genetic bottlenecks during wheat evolution have not had a strong impact on WDV resistance. Further, this study indicates that the variation in susceptibility may be associated with the genome type and that the ancestor Ae. tauschii may be useful as genetic resource for the improvement of WDV resistance in wheat. PMID

  2. Complementation of sugary-1 phenotype in rice endosperm with the wheat isoamylase1 gene supports a direct role for isoamylase1 in amylopectin biosynthesis.

    PubMed

    Kubo, Akiko; Rahman, Sadequr; Utsumi, Yoshinori; Li, Zhongyi; Mukai, Yasuhiko; Yamamoto, Maki; Ugaki, Masashi; Harada, Kyuya; Satoh, Hikaru; Konik-Rose, Christine; Morell, Matthew; Nakamura, Yasunori

    2005-01-01

    To examine the role of isoamylase1 (ISA1) in amylopectin biosynthesis in plants, a genomic DNA fragment from Aegilops tauschii was introduced into the ISA1-deficient rice (Oryza sativa) sugary-1 mutant line EM914, in which endosperm starch is completely replaced by phytoglycogen. A. tauschii is the D genome donor of wheat (Triticum aestivum), and the introduced fragment effectively included the gene for ISA1 for wheat (TaISA1) that was encoded on the D genome. In TaISA1-expressing rice endosperm, phytoglycogen synthesis was substantially replaced by starch synthesis, leaving only residual levels of phytoglycogen. The levels of residual phytoglycogen present were inversely proportional to the expression level of the TaISA1 protein, although the level of pullulanase that had been reduced in EM914 was restored to the same level as that in the wild type. Small but significant differences were found in the amylopectin chain-length distribution, gelatinization temperatures, and A-type x-ray diffraction patterns of the starches from lines expressing TaISA1 when compared with wild-type rice starch, although in the first two parameters, the effect was proportional to the expression level of TaISA. The impact of expression levels of ISA1 on starch structure and properties provides support for the view that ISA1 is directly involved in the synthesis of amylopectin. PMID:15618430

  3. New insights into the wheat chromosome 4D structure and virtual gene order, revealed by survey pyrosequencing

    PubMed Central

    Helguera, Marcelo; Rivarola, Máximo; Clavijo, Bernardo; Martis, Mihaela M.; Vanzetti, Leonardo S.; González, Sergio; Garbus, Ingrid; Leroy, Phillippe; Šimková, Hana; Valárik, Miroslav; Caccamo, Mario; Doležel, Jaroslav; Mayer, Klaus F.X.; Feuillet, Catherine; Tranquilli, Gabriela; Paniego, Norma; Echenique, Viviana

    2015-01-01

    Survey sequencing of the bread wheat (Triticum aestivum L.) genome (AABBDD) has been approached through different strategies delivering important information. However, the current wheat sequence knowledge is not complete. The aim of our study is to provide different and complementary set of data for chromosome 4D. A survey sequence was obtained by pyrosequencing of flow-sorted 4DS (7.2×) and 4DL (4.1×) arms. Single ends (SE) and long mate pairs (LMP) reads were assembled into contigs (223 Mb) and scaffolds (65 Mb) that were aligned to Aegilops tauschii draft genome (DD), anchoring 34 Mb to chromosome 4. Scaffolds annotation rendered 822 gene models. A virtual gene order comprising 1973 wheat orthologous gene loci and 381 wheat gene models was built. This order was largely consistent with the scaffold order determined based on a published high density map from the Ae. tauschii chromosome 4, using bin-mapped 4D ESTs as a common reference. The virtual order showed a higher collinearity with homeologous 4B compared to 4A. Additionally, a virtual map was constructed and ∼5700 genes (∼2200 on 4DS and ∼3500 on 4DL) predicted. The sequence and virtual order obtained here using the 454 platform were compared with the Illumina one used by the IWGSC, giving complementary information. PMID:25711827

  4. A New Class of Wheat Gliadin Genes and Proteins

    PubMed Central

    Anderson, Olin D.; Dong, Lingli; Huo, Naxin; Gu, Yong Q.

    2012-01-01

    The utility of mining DNA sequence data to understand the structure and expression of cereal prolamin genes is demonstrated by the identification of a new class of wheat prolamins. This previously unrecognized wheat prolamin class, given the name δ-gliadins, is the most direct ortholog of barley γ3-hordeins. Phylogenetic analysis shows that the orthologous δ-gliadins and γ3-hordeins form a distinct prolamin branch that existed separate from the γ-gliadins and γ-hordeins in an ancestral Triticeae prior to the branching of wheat and barley. The expressed δ-gliadins are encoded by a single gene in each of the hexaploid wheat genomes. This single δ-gliadin/γ3-hordein ortholog may be a general feature of the Triticeae tribe since examination of ESTs from three barley cultivars also confirms a single γ3-hordein gene. Analysis of ESTs and cDNAs shows that the genes are expressed in at least five hexaploid wheat cultivars in addition to diploids Triticum monococcum and Aegilops tauschii. The latter two sequences also allow assignment of the δ-gliadin genes to the A and D genomes, respectively, with the third sequence type assumed to be from the B genome. Two wheat cultivars for which there are sufficient ESTs show different patterns of expression, i.e., with cv Chinese Spring expressing the genes from the A and B genomes, while cv Recital has ESTs from the A and D genomes. Genomic sequences of Chinese Spring show that the D genome gene is inactivated by tandem premature stop codons. A fourth δ-gliadin sequence occurs in the D genome of both Chinese Spring and Ae. tauschii, but no ESTs match this sequence and limited genomic sequences indicates a pseudogene containing frame shifts and premature stop codons. Sequencing of BACs covering a 3 Mb region from Ae. tauschii locates the δ-gliadin gene to the complex Gli-1 plus Glu-3 region on chromosome 1. PMID:23284903

  5. A new class of wheat gliadin genes and proteins.

    PubMed

    Anderson, Olin D; Dong, Lingli; Huo, Naxin; Gu, Yong Q

    2012-01-01

    The utility of mining DNA sequence data to understand the structure and expression of cereal prolamin genes is demonstrated by the identification of a new class of wheat prolamins. This previously unrecognized wheat prolamin class, given the name δ-gliadins, is the most direct ortholog of barley γ3-hordeins. Phylogenetic analysis shows that the orthologous δ-gliadins and γ3-hordeins form a distinct prolamin branch that existed separate from the γ-gliadins and γ-hordeins in an ancestral Triticeae prior to the branching of wheat and barley. The expressed δ-gliadins are encoded by a single gene in each of the hexaploid wheat genomes. This single δ-gliadin/γ3-hordein ortholog may be a general feature of the Triticeae tribe since examination of ESTs from three barley cultivars also confirms a single γ3-hordein gene. Analysis of ESTs and cDNAs shows that the genes are expressed in at least five hexaploid wheat cultivars in addition to diploids Triticum monococcum and Aegilops tauschii. The latter two sequences also allow assignment of the δ-gliadin genes to the A and D genomes, respectively, with the third sequence type assumed to be from the B genome. Two wheat cultivars for which there are sufficient ESTs show different patterns of expression, i.e., with cv Chinese Spring expressing the genes from the A and B genomes, while cv Recital has ESTs from the A and D genomes. Genomic sequences of Chinese Spring show that the D genome gene is inactivated by tandem premature stop codons. A fourth δ-gliadin sequence occurs in the D genome of both Chinese Spring and Ae. tauschii, but no ESTs match this sequence and limited genomic sequences indicates a pseudogene containing frame shifts and premature stop codons. Sequencing of BACs covering a 3 Mb region from Ae. tauschii locates the δ-gliadin gene to the complex Gli-1 plus Glu-3 region on chromosome 1. PMID:23284903

  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. Electrophoretic survey of seedling esterases in wheats in relation to their phylogeny.

    PubMed

    Jaaska, V

    1980-11-01

    Evolutionary and ontogenetic variation of six seedling esterases of independent genetic control is studied in polyploid wheats and their diploid relatives by means of polyacrylamide gel electrophoresis. Four of them are shown to be controlled by homoeoallelic genes in chromosomes of third, sixth and seventh homoeologous groups.The isoesterase electrophoretic data are considered supporting a monophyletic origin of both the primitive tetraploid and the primitive hexaploid wheat from which contemporary taxa of polyploid wheats have emerged polyphyletically and polytopically through recurrent introgressive hybridization and accumulation of mutations. Ancestral diploids belonging or closely related to Triticum boeoticum, T. urartu, Aegilops speltoides and Ae. tauschii ssp. strangulata are genetically the most suitable genome donors of polyploid wheats. Diploids of the Emarginata subsection of the section Sitopsis, Aegilops longissima s.str., Ae. sharonensis, Ae. searsii and Ae. bicornis, are unsuitable for the role of the wheat B genome donors, being all fixed for the esterase B and D electromorphs different from those of tetraploid wheats. PMID:24305916

  8. The origin of the B-genome of bread wheat (Triticum aestivum L.).

    PubMed

    Haider, N

    2013-03-01

    Understanding the origin of cultivated wheats would further their genetic improvement. The hexaploid bread wheat (Triticum aestivum L., AABBDD) is believed to have originated through one or more rare hybridization events between Aegilops tauschii (DD) and the tetraploid T. turgidum (AABB). Progenitor of the A-genome of the tetraploid and hexaploid wheats has generally been accepted to be T. urartu. In spite of the large number of attempts and published reports about the origin of the B-genome in cultivated wheats, the donor of the B-genome is still relatively unknown and controversial and, hence, remains open. This genome has been found to be closely related to the S-genome of the Sitopsis section (Ae. speltoides, Ae. longissima, Ae. sharonensis, Ae. searsii, and Ae. bicornis) of the genus Aegilops L. Among Sitopsis species, the most positive evidence has been accumulated for Ae. speltoides as the progenitor of the B-genome. Therefore, one or more of the Sitopsis species were proposed frequently as the B-genome donor. Although several reviews have been written on the origin of the genomes of wheat over the years, this paper will attempt for the first time to review the immense literature on the subject, with a particular emphasis on the B-genome which has attracted a huge attention over some 100 years. The ambiguity and conflicting results in most of the methods employed in deducing the precise B-genome donor/s to bread wheat are also discussed. PMID:23755530

  9. Isolation, promoter analysis and expression profile of Dreb2 in response to drought stress in wheat ancestors.

    PubMed

    Tavakol, Elahe; Sardaro, Maria Luisa Savo; Shariati, J Vahid; Rossini, Laura; Porceddu, Enrico

    2014-10-01

    Drought is one of the most important abiotic stresses, constraining crop production seriously. The dehydration responsive element binding proteins (DREBs) are important plant-specific transcription factors that respond to various abiotic stresses and consequently induce abiotic stress-related genes that impart stress endurance in plants. Wild species are naturally exposed to various abiotic stresses and potentially harbor suitable alleles through natural selection. In this study we isolated and characterized Dreb2 from Triticum urartu (GenBank: KF731664), Aegilops speltoides (GenBank: KF731665) and Aegilops tauschii (GenBank: KF731663), the A, B and D genome ancestors of bread wheat, respectively. Analysis of over 1.3 kb upstream region of the gene revealed the presence of several conserved cis-acting regulatory elements including ABA-responsive elements, low temperature responsive elements, and several light and environmental signaling related motifs potentially vindicate Dreb2 responses to environmental signals. Moreover, the gene exhibited an alternative splicing, conserved among orthologous genes in grasses, and produced a non-functional isoform due to splicing in an exon resulted frame-shift creating an early stop codon before the functional domain. The expression analysis of Dreb2 under normal and different levels of dehydration stress conditions indicated that the two active spliced isoforms are upregulated when the plant exposed to drought stress whereas the non-functional isoform is downregulated in severe drought. PMID:25017054

  10. A comparative evaluation of mutagenic, antimutagenic, radical scavenging and antibacterial activities of essential oils of Pituranthos chloranthus (Coss. et Dur.).

    PubMed

    Neffati, Aicha; Limem, Ilef; Kilani, Soumaya; Bouhlel, Ines; Skandrani, Ines; Bhouri, Wissem; Ben Sghaier, Mohamed; Boubaker, Jihed; Ledauphin, Jerome; Barillier, Daniel; Ghedira, Leila Chekir; Ghedira, Kamel

    2009-01-01

    The Salmonella typhimurium/microsome assay is a widely used bacterial genotoxicity assay to test potential carcinogens. The aim of this work was to evaluate the mutagenic and antimutagenic activities with and without the addition of an extrinsic metabolic activation system of essential oils obtained from an aerial part of Pituranthos chloranthus harvested from different stations in Tunisia. The oils showed no mutagenicity when tested with S. typhimurium strains TA98, TA100, and TA1535. On the other hand, we showed that these essential oils reduced significantly Benzo [a] pyrene (B[a] P) and sodium-azide-induced mutagenicity. The scavenging capacity of these essential oils was also estimated by evaluating the inhibition of DPPH radical. Essential oils harvested at Medenine and Gabes in November were more effective in scavenging activity. The essential oils were tested for their antimicrobial properties against five different bacteria, and were found to be weakly active, with MIC and MBC values in the range 0.6-4 and 2.2-5 mg/mL, respectively. PMID:19793030

  11. Alleviation of Cadmium Toxicity in Brassica juncea L. (Czern. & Coss.) by Calcium Application Involves Various Physiological and Biochemical Strategies

    PubMed Central

    Ahmad, Parvaiz; Sarwat, Maryam; Bhat, Nazir Ahmad; Wani, Mohd Rafiq; Kazi, Alvina Gul; Tran, Lam-Son Phan

    2015-01-01

    Calcium (Ca) plays important role in plant development and response to various environmental stresses. However, its involvement in mitigation of heavy metal stress in plants remains elusive. In this study, we examined the effect of Ca (50 mM) in controlling cadmium (Cd) uptake in mustard (Brassica juncea L.) plants exposed to toxic levels of Cd (200 mg L−1 and 300 mg L−1). The Cd treatment showed substantial decrease in plant height, root length, dry weight, pigments and protein content. Application of Ca improved the growth and biomass yield of the Cd-stressed mustard seedlings. More importantly, the oil content of mustard seeds of Cd-stressed plants was also enhanced with Ca treatment. Proline was significantly increased in mustard plants under Cd stress, and exogenously sprayed Ca was found to have a positive impact on proline content in Cd-stressed plants. Different concentrations of Cd increased lipid peroxidation but the application of Ca minimized it to appreciable level in Cd-treated plants. Excessive Cd treatment enhanced the activities of antioxidant enzymes superoxide dismutase, ascorbate peroxidase and glutathione reductase, which were further enhanced by the addition of Ca. Additionally, Cd stress caused reduced uptake of essential elements and increased Cd accumulation in roots and shoots. However, application of Ca enhanced the concentration of essential elements and decreased Cd accumulation in Cd-stressed plants. Our results indicated that application of Ca enables mustard plant to withstand the deleterious effect of Cd, resulting in improved growth and seed quality of mustard plants. PMID:25629695

  12. Alleviation of cadmium toxicity in Brassica juncea L. (Czern. & Coss.) by calcium application involves various physiological and biochemical strategies.

    PubMed

    Ahmad, Parvaiz; Sarwat, Maryam; Bhat, Nazir Ahmad; Wani, Mohd Rafiq; Kazi, Alvina Gul; Tran, Lam-Son Phan

    2015-01-01

    Calcium (Ca) plays important role in plant development and response to various environmental stresses. However, its involvement in mitigation of heavy metal stress in plants remains elusive. In this study, we examined the effect of Ca (50 mM) in controlling cadmium (Cd) uptake in mustard (Brassica juncea L.) plants exposed to toxic levels of Cd (200 mg L(-1) and 300 mg L(-1)). The Cd treatment showed substantial decrease in plant height, root length, dry weight, pigments and protein content. Application of Ca improved the growth and biomass yield of the Cd-stressed mustard seedlings. More importantly, the oil content of mustard seeds of Cd-stressed plants was also enhanced with Ca treatment. Proline was significantly increased in mustard plants under Cd stress, and exogenously sprayed Ca was found to have a positive impact on proline content in Cd-stressed plants. Different concentrations of Cd increased lipid peroxidation but the application of Ca minimized it to appreciable level in Cd-treated plants. Excessive Cd treatment enhanced the activities of antioxidant enzymes superoxide dismutase, ascorbate peroxidase and glutathione reductase, which were further enhanced by the addition of Ca. Additionally, Cd stress caused reduced uptake of essential elements and increased Cd accumulation in roots and shoots. However, application of Ca enhanced the concentration of essential elements and decreased Cd accumulation in Cd-stressed plants. Our results indicated that application of Ca enables mustard plant to withstand the deleterious effect of Cd, resulting in improved growth and seed quality of mustard plants. PMID:25629695

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

    PubMed Central

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

    2013-01-01

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

  14. Comparison of genome-wide gene expression patterns in the seedlings of nascent allohexaploid wheats produced by two combinations of hybrids.

    PubMed

    Jung, Yeonju; Kawaura, Kanako; Kishii, Masahiro; Sakuma, Shun; Ogihara, Yasunari

    2015-01-01

    Allopolyploidization in plants is an important event that enhances heterosis and environmental adaptation. Common wheat, Triticum aestivum (AABBDD), which is an allohexaploid that evolved from an allopolyploidization event between T. turgidum (AABB) and Aegilops tauschii (DD), shows more growth vigor and wider adaptation than tetraploid wheats. To better understand the molecular basis for the heterosis of hexaploid wheat, we systematically analyzed the genome-wide gene expression patterns of two combinations of newly hybridized triploids (ABD), their chromosome-doubled hexaploids (AABBDD), stable synthetic hexaploids (AABBDD) and natural hexaploids, in addition to their parents, T. turgidum (AABB) and Ae. tauschii (DD), using a microarray to reconstruct the events of allopolyploidization and genome stabilization. Overall comparisons of gene expression profiles showed that the newly generated hexaploids exhibited gene expression patterns similar to those of their maternal tetraploids, irrespective of hybrid combination. With successive generations, the gene expression profiles of nascent hexaploids became less similar to the maternal profiles, and belonged to a separate cluster from the natural hexaploids. Triploids revealed characteristic expression patterns, suggesting endosperm effects. In the newly hybridized triploids (ABD) of two independent synthetic lines, approximately one-fifth of expressed genes displayed non-additive expression; the number of these genes decreased with polyploidization and genome stabilization. Approximately 20% of the non-additively expressed genes were transmitted across generations throughout allopolyploidization and successive self-pollinations, and 43 genes overlapped between the two combinations, indicating that shared gene expression patterns can be seen during allohexaploidization. Furthermore, four of these 43 genes were involved in starch and sucrose metabolism, suggesting that these metabolic events play key roles in the

  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. Sequencing of 15 622 gene-bearing BACs clarifies the gene-dense regions of the barley genome.

    PubMed

    Muñoz-Amatriaín, María; Lonardi, Stefano; Luo, MingCheng; Madishetty, Kavitha; Svensson, Jan T; Moscou, Matthew J; Wanamaker, Steve; Jiang, Tao; Kleinhofs, Andris; Muehlbauer, Gary J; Wise, Roger P; Stein, Nils; Ma, Yaqin; Rodriguez, Edmundo; Kudrna, Dave; Bhat, Prasanna R; Chao, Shiaoman; Condamine, Pascal; Heinen, Shane; Resnik, Josh; Wing, Rod; Witt, Heather N; Alpert, Matthew; Beccuti, Marco; Bozdag, Serdar; Cordero, Francesca; Mirebrahim, Hamid; Ounit, Rachid; Wu, Yonghui; You, Frank; Zheng, Jie; Simková, Hana; Dolezel, Jaroslav; Grimwood, Jane; Schmutz, Jeremy; Duma, Denisa; Altschmied, Lothar; Blake, Tom; Bregitzer, Phil; Cooper, Laurel; Dilbirligi, Muharrem; Falk, Anders; Feiz, Leila; Graner, Andreas; Gustafson, Perry; Hayes, Patrick M; Lemaux, Peggy; Mammadov, Jafar; Close, Timothy J

    2015-10-01

    Barley (Hordeum vulgare L.) possesses a large and highly repetitive genome of 5.1 Gb that has hindered the development of a complete sequence. In 2012, the International Barley Sequencing Consortium released a resource integrating whole-genome shotgun sequences with a physical and genetic framework. However, because only 6278 bacterial artificial chromosome (BACs) in the physical map were sequenced, fine structure was limited. To gain access to the gene-containing portion of the barley genome at high resolution, we identified and sequenced 15 622 BACs representing the minimal tiling path of 72 052 physical-mapped gene-bearing BACs. This generated ~1.7 Gb of genomic sequence containing an estimated 2/3 of all Morex barley genes. Exploration of these sequenced BACs revealed that although distal ends of chromosomes contain most of the gene-enriched BACs and are characterized by high recombination rates, there are also gene-dense regions with suppressed recombination. We made use of published map-anchored sequence data from Aegilops tauschii to develop a synteny viewer between barley and the ancestor of the wheat D-genome. Except for some notable inversions, there is a high level of collinearity between the two species. The software HarvEST:Barley provides facile access to BAC sequences and their annotations, along with the barley-Ae. tauschii synteny viewer. These BAC sequences constitute a resource to improve the efficiency of marker development, map-based cloning, and comparative genomics in barley and related crops. Additional knowledge about regions of the barley genome that are gene-dense but low recombination is particularly relevant. PMID:26252423

  17. 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

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

    PubMed

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

    2014-08-12

    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

  19. Development of a set of oligonucleotide primers specific for genes at the Glu-1 complex loci of wheat.

    PubMed

    D'Ovidio, R; Masci, S; Porceddu, E

    1995-07-01

    Specific amplification of the complete coding region of all six high-molecular-weight (HMW) glutenin genes present in hexaploid wheat was obtained by the polyerase chain reaction (PCR). Primers specific for the N-terminal region of the 1Dx gene and for the repetitive domain of the y-type HMW glutenin genes were also developed. Although the primers were constructed on the basis of the nucleotide sequences of HMW glutenin genes present in T. aestivum L. cv 'Cheyenne', they were very efficient in amplifying HMW glutenin genes of diploid and tetraploid wheat species. PCR analysis of HMW glutenin genes of T. urartu Tuman., T. longissimum (Schweinf. & Muschl.) Bowden and T. speltoides (Tausch) Gren. ex Richt, showed a high degree of length polymorphism, whereas a low degree of length variation was found in accessions of T. tauschii (Coss.) Schmal. Furthermore, using primers specific for the repetitive regions of HMW genes, we could demonstrate that the size variation observed was due to a different length of the central repetitive domain. The usefulness of the PCR-based approach to analyze the genetic polymorphism of HMW glutenin genes, to isolate new allelic variants, to estimate their molecular size and to verify the number of cysteine residues is discussed. PMID:24169762

  20. Within- and trans-generational plasticity affects the opportunity for selection in barbed goatgrass (Aegilops Triuncialis)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although genetic change can enhance the success of many biological invaders, phenotypic plasticity may also facilitate establishment and spread of introduced species in new environments. To determine if processes influencing the opportunity for selection differ between resource- rich and resource- p...

  1. Integrated weed management systems identified for jointed goatgrass (Aegilops cylindrica) in the Pacific Northwest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Jointed goatgrass is an invasive winter annual grass weed that is a particular problem in the low- to intermediate-rainfall zones of the Pacific Northwest (PNW). For the most part, single-component research has been the focus of previous jointed goatgrass studies. In 1996, an integrated field syst...

  2. Jointed goatgrass (Aegilops cylindrica) by imidazolinone-resistant wheat hybridization under field conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gene flow between jointed goatgrass and winter wheat is a concern because transfer of herbicide resistance genes from imidazolinone-resistant (IR) winter wheat cultivars to jointed goatgrass could restrict weed management options for this serious weed of winter wheat cropping systems. The objective...

  3. Patterns of introduction and adaptation during the invasion of Aegilops truncialis (Poaceae) into Californian serpentine soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    - Multiple introductions appear to be playing a prominent role to explain the success of biological invasions. One often cited mechanism is the prevention of a genetic bottleneck by the parallel introduction of several distinct genotypes, which in turn provides the heritable variation that can allow...

  4. Mapping QTL for resistance to eyespot of wheat in Aegilops longissima

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eyespot is an economically important disease of wheat caused by the soilborne fungi Oculimacula yal- lundae and O. acuformis. These pathogens infect and colonize the stem base, which results in lodging of diseased plants and reduced grain yield. Disease resistant cultivars are the most desirable co...

  5. Generation of Wheat Transcription Factor FOX Rice Lines and Systematic Screening for Salt and Osmotic Stress Tolerance

    PubMed Central

    Zhang, Qian; Liu, Yayun; Zhu, Butuo; Cao, Jian; Li, Zhanpeng; Han, Longzhi; Jia, Jizeng; Zhao, Guangyao; Sun, Xuehui

    2015-01-01

    Transcription factors (TFs) play important roles in plant growth, development, and responses to environmental stress. In this study, we collected 1,455 full-length (FL) cDNAs of TFs, representing 45 families, from wheat and its relatives Triticum urartu, Aegilops speltoides, Aegilops tauschii, Triticum carthlicum, and Triticum aestivum. More than 15,000 T0 TF FOX (Full-length cDNA Over-eXpressing) rice lines were generated; of these, 10,496 lines set seeds. About 14.88% of the T0 plants showed obvious phenotypic changes. T1 lines (5,232 lines) were screened for salt and osmotic stress tolerance using 150 mM NaCl and 20% (v/v) PEG-4000, respectively. Among them, five lines (591, 746, 1647, 1812, and J4065) showed enhanced salt stress tolerance, five lines (591, 746, 898, 1078, and 1647) showed enhanced osmotic stress tolerance, and three lines (591, 746, and 1647) showed both salt and osmotic stress tolerance. Further analysis of the T-DNA flanking sequences showed that line 746 over-expressed TaEREB1, line 898 over-expressed TabZIPD, and lines 1812 and J4065 over-expressed TaOBF1a and TaOBF1b, respectively. The enhanced salt and osmotic stress tolerance of lines 898 and 1812 was confirmed by retransformation of the respective genes. Our results demonstrate that a heterologous FOX system may be used as an alternative genetic resource for the systematic functional analysis of the wheat genome. PMID:26176782

  6. Genetic map of Triticum turgidum based on a hexaploid wheat population without genetic recombination for D genome

    PubMed Central

    2012-01-01

    Background A synthetic doubled-haploid hexaploid wheat population, SynDH1, derived from the spontaneous chromosome doubling of triploid F1 hybrid plants obtained from the cross of hybrids Triticum turgidum ssp. durum line Langdon (LDN) and ssp. turgidum line AS313, with Aegilops tauschii ssp. tauschii accession AS60, was previously constructed. SynDH1 is a tetraploidization-hexaploid doubled haploid (DH) population because it contains recombinant A and B chromosomes from two different T. turgidum genotypes, while all the D chromosomes from Ae. tauschii are homogenous across the whole population. This paper reports the construction of a genetic map using this population. Results Of the 606 markers used to assemble the genetic map, 588 (97%) were assigned to linkage groups. These included 513 Diversity Arrays Technology (DArT) markers, 72 simple sequence repeat (SSR), one insertion site-based polymorphism (ISBP), and two high-molecular-weight glutenin subunit (HMW-GS) markers. These markers were assigned to the 14 chromosomes, covering 2048.79 cM, with a mean distance of 3.48 cM between adjacent markers. This map showed good coverage of the A and B genome chromosomes, apart from 3A, 5A, 6A, and 4B. Compared with previously reported maps, most shared markers showed highly consistent orders. This map was successfully used to identify five quantitative trait loci (QTL), including two for spikelet number on chromosomes 7A and 5B, two for spike length on 7A and 3B, and one for 1000-grain weight on 4B. However, differences in crossability QTL between the two T. turgidum parents may explain the segregation distortion regions on chromosomes 1A, 3B, and 6B. Conclusions A genetic map of T. turgidum including 588 markers was constructed using a synthetic doubled haploid (SynDH) hexaploid wheat population. Five QTLs for three agronomic traits were identified from this population. However, more markers are needed to increase the density and resolution of this map in the

  7. Prevalence of gene expression additivity in genetically stable wheat allohexaploids.

    PubMed

    Chelaifa, Houda; Chagué, Véronique; Chalabi, Smahane; Mestiri, Imen; Arnaud, Dominique; Deffains, Denise; Lu, Yunhai; Belcram, Harry; Huteau, Virginie; Chiquet, Julien; Coriton, Olivier; Just, Jérémy; Jahier, Joseph; Chalhoub, Boulos

    2013-02-01

    The reprogramming of gene expression appears as the major trend in synthetic and natural allopolyploids where expression of an important proportion of genes was shown to deviate from that of the parents or the average of the parents. In this study, we analyzed gene expression changes in previously reported, highly stable synthetic wheat allohexaploids that combine the D genome of Aegilops tauschii and the AB genome extracted from the natural hexaploid wheat Triticum aestivum. A comprehensive genome-wide analysis of transcriptional changes using the Affymetrix GeneChip Wheat Genome Array was conducted. Prevalence of gene expression additivity was observed where expression does not deviate from the average of the parents for 99.3% of 34,820 expressed transcripts. Moreover, nearly similar expression was observed (for 99.5% of genes) when comparing these synthetic and natural wheat allohexaploids. Such near-complete additivity has never been reported for other allopolyploids and, more interestingly, for other synthetic wheat allohexaploids that differ from the ones studied here by having the natural tetraploid Triticum turgidum as the AB genome progenitor. Our study gave insights into the dynamics of additive gene expression in the highly stable wheat allohexaploids. PMID:23278496

  8. Development, identification and utilization of introgression lines using Chinese endemic and synthetic wheat as donors.

    PubMed

    Gu, Liqing; Wei, Bo; Fan, Renchun; Jia, Xu; Wang, Xianping; Zhang, Xiangqi

    2015-08-01

    Chromosome segmental introgression lines (ILs) are an effective way to utilize germplasm resources in crops. To improve agronomic traits of wheat cultivar (Triticum aestivum) Shi 4185, four sets of ILs were developed. The donors were Chinese endemic subspecies accessions Yunnan wheat (T. aestivum ssp. yunnanense) YN3, Tibetan semi-wild wheat (T. aestivum ssp. tibetanum) XZ-ZM19450, and Xinjiang wheat (T. aestivum ssp. petropavlovskyi) XJ5, and synthetic wheat HC-XM1620 derived from a cross between T. durum acc. D67.2/P66.270 with Aegilops tauschii acc. 218. Totals of 356, 366, 445 and 457 simple sequence repeat (SSR) markers were polymorphic between Shi 4185 and YN3, XZ-ZM19450, XJ5 and HC-XM1620, respectively. In total, 991 ILs were identified, including 300 derived from YN3, covering 95% of the genome of Shi 4185, 218 from XZ-ZM19450 (79%), 279 from XJ5 (97%), and 194 from HC-ZX1620 (84%). The sizes and locations of each introgression were determined from a consensus SSR linkage map. Using the ILs, 11 putative quantitative trait loci (QTLs) were identified for plant height (PH), spike length (SL) and grain number per spike (GNS). Comparative analyses of 24 elite ILs with the parents revealed that the four donor parents could be important resources to improve wheat SL and GNS. Our work offers a case for utilizing endemic landraces for QTL mapping and improvement of wheat cultivars using introgression lines. PMID:25545589

  9. Cloning and characterization of four B-hordein genes from Tibetan hull-less barley (Hordeum vulgare subsp. vulgare).

    PubMed

    Han, Zhao-Xue; Qian, Gang; Pan, Zhi-Fen; Deng, Guang-Bing; Wu, Fang; Tang, Ya-Wei; Qiang, Xiao-Lin; Yu, Mao-Qun

    2006-10-01

    Four B-hordein genes, designated BH1-BH4, were cloned using PCR amplification from two hull-less barley cultivars, ZQ7239 and ZQ148, collected from Tibet. The results of sequencing indicated that BH1-BH4 contained complete open reading frames (ORFs). Comparison of their predicted polypeptide sequences with the published sequences suggested that they all share the same basic protein structure. Phylogenetic analysis indicated that the deduced amino-acid sequences of BH1-BH4 genes were more closely related to B-hordeins from cultivated barley (Hordeum vulgare L.) than to any other prolamins from wild barley and Aegilops tauschii. Comparison of the coding regions of BH1-BH4 genes showed that BH1 had a lower sequence identity to other previously published B-hordeins than the other three B-hordeins obtained in this study. BH1 was then cloned in a bacterial expression vector based on bacteriophage T7 RNA polymerase. The resulting plasmid produced a 28.15 kDa protein in Escherichia coli. The potential value of B-hordein genes in grain quality improvement of hull-less barley has been discussed. PMID:17046594

  10. A novel family of γ-gliadin genes are highly regulated by nitrogen supply in developing wheat grain

    PubMed Central

    Shewry, Peter R.

    2013-01-01

    Six wheat cultivars were grown at Rothamsted (UK) with three levels of nitrogen fertilizer (100, 200 and 350kg N/ha) in 2009 and 2010. Gene expression in developing caryopses at 21 days post-anthesis (DPA) was profiled using the Affymetrix Wheat GeneChip®. Four of 105 transcripts which were significantly upregulated by nitrogen level were annotated as γ-3 hordein and the identification of corresponding expressed sequence tags showed that they differed in sequence from previously described (typical) γ-gliadins and represented a novel form of γ-gliadin. Real-time reverse transcriptase PCR at 14, 21, 28 and 35 DPA revealed that this transcript was most abundant and most responsive to nitrogen at 21 DPA. Four novel γ-gliadin genes were isolated by PCR amplification from wheat cv. Hereward and the related species Aegilops tauschii and Triticum monococcum while three were assembled from the genomic sequence database of wheat cv. Chinese Spring (www.cerealsdb.uk.net). Comparison of the deduced amino acid sequences of the seven genes showed that they shared only 44.4–46.0% identity with the sequence of a typical γ-gliadin (accession number EF15018), but 61.8–68.3% identity with the sequence of γ-3 hordein from the wild barley species Hordeum chilense (AY338065). The novel γ-gliadin genes were localized to the group 1 chromosomes (1A, 1B, 1D). PMID:23162123

  11. Identification of quantitative trait loci for abscisic acid responsiveness in the D-genome of hexaploid wheat.

    PubMed

    Iehisa, Julio C M; Matsuura, Takakazu; Mori, Izumi C; Yokota, Hirokazu; Kobayashi, Fuminori; Takumi, Shigeo

    2014-06-15

    In crop species such as wheat, abiotic stresses and preharvest sprouting reduce grain yield and quality. The plant hormone abscisic acid (ABA) plays important roles in abiotic stress tolerance and seed dormancy. In previous studies, we evaluated ABA responsiveness of 67 Aegilops tauschii accessions and their synthetic hexaploid wheat lines, finding wide variation that was due to the D-genome. In this study, quantitative trait locus (QTL) analysis was performed using an F2 population derived from crosses of highly ABA-responsive and less-responsive synthetic wheat lines. A significant QTL was detected on chromosome 6D, in a similar location to that reported for ABA responsiveness using recombinant inbred lines derived from common wheat cultivars Mironovskaya 808 and Chinese Spring. A comparative map and physiological and expression analyses of the 6D QTL suggested that this locus involved in line differences among wheat synthetics is different from that involved in cultivar differences in common wheat. The common wheat 6D QTL was found to affect seed dormancy and the regulation of cold-responsive/late embryogenesis abundant genes during dehydration. However, in synthetic wheat, we failed to detect any association of ABA responsiveness with abiotic stress tolerance or seed dormancy, at least under our experimental conditions. Development of near-isogenic lines will be important for functional analyses of the synthetic wheat 6D QTL. PMID:24877675

  12. Comparison of gene expression profiles and responses to zinc chloride among inter- and intraspecific hybrids with growth abnormalities in wheat and its relatives.

    PubMed

    Takamatsu, Kiyofumi; Iehisa, Julio C M; Nishijima, Ryo; Takumi, Shigeo

    2015-07-01

    Hybrid necrosis is a well-known reproductive isolation mechanism in plant species, and an autoimmune response is generally considered to trigger hybrid necrosis through epistatic interaction between disease resistance-related genes in hybrids. In common wheat, the complementary Ne1 and Ne2 genes control hybrid necrosis, defined as type I necrosis. Two other types of hybrid necrosis (type II and type III) have been observed in interspecific hybrids between tetraploid wheat and Aegilops tauschii. Another type of hybrid necrosis, defined here as type IV necrosis, has been reported in F1 hybrids between Triticum urartu and some accessions of Triticum monococcum ssp. aegilopoides. In types I, III and IV, cell death occurs gradually starting in older tissues, whereas type II necrosis symptoms occur only under low temperature. To compare comprehensive gene expression patterns of hybrids showing growth abnormalities, transcriptome analysis of type I and type IV necrosis was performed using a wheat 38k oligo-DNA microarray. Defense-related genes including many WRKY transcription factor genes were dramatically up-regulated in plants showing type I and type IV necrosis, similarly to other known hybrid abnormalities, suggesting an association with an autoimmune response. Reactive oxygen species generation and necrotic cell death were effectively inhibited by ZnCl2 treatment in types I, III and IV necrosis, suggesting a significant association of Ca(2+) influx in upstream signaling of necrotic cell death in wheat hybrid necrosis. PMID:26081164

  13. Haplotype variation of Green Revolution gene Rht-D1 during wheat domestication and improvement.

    PubMed

    Zhang, Chihong; Gao, Lifeng; Sun, Jiaqiang; Jia, Jizeng; Ren, Zhenglong

    2014-08-01

    Green Revolution made a substantial contribution to wheat yields worldwide in the 1960s and 1970s. It is of great importance to analyze the haplotype variation of Rht-D1, the Green Revolution gene, during wheat (Triticum aestivum L.) domestication and breeding to understand its evolution and function in wheat breeding history. In this study, the Rht-D1 and its flanking regions were sequenced and single nucleotide polymorphisms were detected based on a panel of 45 accessions of Aegilops tauschii, 51 accessions of landraces and 80 accessions of commercial varieties. Genetic diversity in the wild accessions was much higher than that in the varieties and higher than that reported previously. Seven haplotypes (Hapl I to Hapl VII) of Rht-D1 were identified and their evolutionary relationships were proposed. In addition to the well-known Green Revolution allele Rht-D1b, Hapl VII (an allele Rht-D1k) was identified in early breeding varieties, which reduced plant height by 16%. The results suggested that Rht-D1k had been used in breeding before the Green Revolution and made a great contribution to wheat production worldwide. Based on the breeding history and molecular evidence, we proposed that the wheat Green Revolution in China and International Maize and Wheat Improvement Center (CIMMYT) occurred independently. PMID:24645900

  14. Regions of the bread wheat D genome associated with variation in key photosynthesis traits and shoot biomass under both well watered and water deficient conditions.

    PubMed

    Osipova, Svetlana; Permyakov, Alexey; Permyakova, Marina; Pshenichnikova, Tatyana; Verkhoturov, Vasiliy; Rudikovsky, Alexandr; Rudikovskaya, Elena; Shishparenok, Alexandr; Doroshkov, Alexey; Börner, Andreas

    2016-05-01

    A quantitative trait locus (QTL) approach was taken to reveal the genetic basis in wheat of traits associated with photosynthesis during a period of exposure to water deficit stress. The performance, with respect to shoot biomass, gas exchange and chlorophyll fluorescence, leaf pigment content and the activity of various ascorbate-glutathione cycle enzymes and catalase, of a set of 80 wheat lines, each containing a single chromosomal segment introgressed from the bread wheat D genome progenitor Aegilops tauschii, was monitored in plants exposed to various water regimes. Four of the seven D genome chromosomes (1D, 2D, 5D, and 7D) carried clusters of both major (LOD >3.0) and minor (LOD between 2.0 and 3.0) QTL. A major QTL underlying the activity of glutathione reductase was located on chromosome 2D, and another, controlling the activity of ascorbate peroxidase, on chromosome 7D. A region of chromosome 2D defined by the microsatellite locus Xgwm539 and a second on chromosome 7D flanked by the marker loci Xgwm1242 and Xgwm44 harbored a number of QTL associated with the water deficit stress response. PMID:26374127

  15. Extensive Pericentric Rearrangements in the Bread Wheat (Triticum aestivum L.) Genotype “Chinese Spring” Revealed from Chromosome Shotgun Sequence Data

    PubMed Central

    Ma, Jian; Stiller, Jiri; Wei, Yuming; Zheng, You-Liang; Devos, Katrien M.; Doležel, Jaroslav; Liu, Chunji

    2014-01-01

    The bread wheat (Triticum aestivum L.) genotype “Chinese Spring” (“CS”) is the reference base in wheat genetics and genomics. Pericentric rearrangements in this genotype were systematically assessed by analyzing homoeoloci for a set of nonredundant genes from Brachypodium distachyon, Triticum urartu, and Aegilops tauschii in the CS chromosome shotgun sequence obtained from individual chromosome arms flow-sorted from CS aneuploid lines. Based on patterns of their homoeologous arm locations, 551 genes indicated the presence of pericentric inversions in at least 10 of the 21 chromosomes. Available data from deletion bin-mapped expressed sequence tags and genetic mapping in wheat indicated that all inversions had breakpoints in the low-recombinant gene-poor pericentromeric regions. The large number of putative intrachromosomal rearrangements suggests the presence of extensive structural differences among the three subgenomes, at least some of which likely occurred during the production of the aneuploid lines of this hexaploid wheat genotype. These differences could have significant implications in wheat genome research where comparative approaches are used such as in ordering and orientating sequence contigs and in gene cloning. PMID:25349265

  16. Draft genome of the wheat A-genome progenitor Triticum urartu.

    PubMed

    Ling, Hong-Qing; Zhao, Shancen; Liu, Dongcheng; Wang, Junyi; Sun, Hua; Zhang, Chi; Fan, Huajie; Li, Dong; Dong, Lingli; Tao, Yong; Gao, Chuan; Wu, Huilan; Li, Yiwen; Cui, Yan; Guo, Xiaosen; Zheng, Shusong; Wang, Biao; Yu, Kang; Liang, Qinsi; Yang, Wenlong; Lou, Xueyuan; Chen, Jie; Feng, Mingji; Jian, Jianbo; Zhang, Xiaofei; Luo, Guangbin; Jiang, Ying; Liu, Junjie; Wang, Zhaobao; Sha, Yuhui; Zhang, Bairu; Wu, Huajun; Tang, Dingzhong; Shen, Qianhua; Xue, Pengya; Zou, Shenhao; Wang, Xiujie; Liu, Xin; Wang, Famin; Yang, Yanping; An, Xueli; Dong, Zhenying; Zhang, Kunpu; Zhang, Xiangqi; Luo, Ming-Cheng; Dvorak, Jan; Tong, Yiping; Wang, Jian; Yang, Huanming; Li, Zhensheng; Wang, Daowen; Zhang, Aimin; Wang, Jun

    2013-04-01

    Bread wheat (Triticum aestivum, AABBDD) is one of the most widely cultivated and consumed food crops in the world. However, the complex polyploid nature of its genome makes genetic and functional analyses extremely challenging. The A genome, as a basic genome of bread wheat and other polyploid wheats, for example, T. turgidum (AABB), T. timopheevii (AAGG) and T. zhukovskyi (AAGGA(m)A(m)), is central to wheat evolution, domestication and genetic improvement. The progenitor species of the A genome is the diploid wild einkorn wheat T. urartu, which resembles cultivated wheat more extensively than do Aegilops speltoides (the ancestor of the B genome) and Ae. tauschii (the donor of the D genome), especially in the morphology and development of spike and seed. Here we present the generation, assembly and analysis of a whole-genome shotgun draft sequence of the T. urartu genome. We identified protein-coding gene models, performed genome structure analyses and assessed its utility for analysing agronomically important genes and for developing molecular markers. Our T. urartu genome assembly provides a diploid reference for analysis of polyploid wheat genomes and is a valuable resource for the genetic improvement of wheat. PMID:23535596

  17. Polyphenol oxidase (PPO) in wheat and wild relatives: molecular evidence for a multigene family.

    PubMed

    Massa, Alicia N; Beecher, Brian; Morris, Craig F

    2007-05-01

    Wheat polyphenol oxidase (PPO) is the major cause of browning reactions that discolor Asian noodles and other wheat products. It has been hypothesized that genes encoding wheat PPOs may have evolved by gene duplication into a multigene family. Here we characterized PPO genomic sequences from diploid (Triticum monococcum, T. urartu, Aegilops tauschii, and Ae. speltoides), tetraploid (T. turgidum, subspecies dicoccoides and durum) and hexaploid (T. aestivum cultivars Klasic and ID377s) wheat species to gain a better understanding of the structure and organization of PPO genes. DNA fragments were amplified from a highly polymorphic and phylogenetic informative region of the gene. As a result, we obtained highly discriminative sequences. Three distinct PPOs, obtained from the A genome of T. monococcum, provided evidence for gene duplication events (paralogous loci). Furthermore, the number of sequences obtained for bread and durum wheat was higher than the expected number of orthologous loci. Sequence comparison revealed nucleotide and structural diversity, and detected five sequence intron types, all with a common insertion position. This was hypothesized to be homologous to that of intron 2 of previously reported wheat PPOs. A MITE of the Stowaway family accounted for the major difference between the five intervening sequences, and was unique to T. aestivum cv. Klasic. Nucleotide and structural diversity, together with well-resolved phylogenetic trees, provided molecular evidence to support the hypothesis of a PPO multigene family structure and organization. PMID:17468807

  18. Molecular evolution and nucleotide diversity of nuclear plastid phosphoglycerate kinase (PGK) gene in Triticeae (Poaceae).

    PubMed

    Adderley, Shawn; Sun, Genlou

    2014-01-01

    Levels of nucleotide divergence provide key evidence in the evolution of polyploids. The nucleotide diversity of 226 sequences of pgk1 gene in Triticeae species was characterized. Phylogenetic analyses based on the pgk1 gene were carried out to determine the diploid origin of polyploids within the tribe in relation to their A(u), B, D, St, Ns, P, and H haplomes. Sequences from the Ns genome represented the highest nucleotide diversity values for both polyploid and diploid species with π=0.03343 and θ=0.03536 for polyploid Ns genome sequences and π=0.03886 and θ=0.03886 for diploid Psathyrostachys sequences, while Triticum urartu represented the lowest diversity among diploid species at π=0.0011 and θ=0.0011. Nucleotide variation of diploid Aegilops speltoides (π=0.2441, presumed the B genome donor of Triticum species) is five times higher than that (π=0.00483) of B genome in polyploid species. Significant negative Tajima's D values for the St, A(u), and D genomes along with high rates of polymorphisms and low sequence diversity were observed. Origins of the A(u), B, and D genomes were linked to T. urartu, A. speltoides, and A. tauschii, respectively. Putative St genome donor was Pseudoroegneria, while Ns and P donors were Psathyrostachys and Agropyron. H genome diploid donor is Hordeum. PMID:24120623

  19. High Transferability of Homoeolog-Specific Markers between Bread Wheat and Newly Synthesized Hexaploid Wheat Lines.

    PubMed

    Zeng, Deying; Luo, Jiangtao; Li, Zenglin; Chen, Gang; Zhang, Lianquan; Ning, Shunzong; Yuan, Zhongwei; Zheng, Youliang; Hao, Ming; Liu, Dengcai

    2016-01-01

    Bread wheat (Triticum aestivum, 2n = 6x = 42, AABBDD) has a complex allohexaploid genome, which makes it difficult to differentiate between the homoeologous sequences and assign them to the chromosome A, B, or D subgenomes. The chromosome-based draft genome sequence of the 'Chinese Spring' common wheat cultivar enables the large-scale development of polymerase chain reaction (PCR)-based markers specific for homoeologs. Based on high-confidence 'Chinese Spring' genes with known functions, we developed 183 putative homoeolog-specific markers for chromosomes 4B and 7B. These markers were used in PCR assays for the 4B and 7B nullisomes and their euploid synthetic hexaploid wheat (SHW) line that was newly generated from a hybridization between Triticum turgidum (AABB) and the wild diploid species Aegilops tauschii (DD). Up to 64% of the markers for chromosomes 4B or 7B in the SHW background were confirmed to be homoeolog-specific. Thus, these markers were highly transferable between the 'Chinese Spring' bread wheat and SHW lines. Homoeolog-specific markers designed using genes with known functions may be useful for genetic investigations involving homoeologous chromosome tracking and homoeolog expression and interaction analyses. PMID:27611704

  20. Making the Bread: Insights from Newly Synthesized Allohexaploid Wheat.

    PubMed

    Li, Ai-li; Geng, Shuai-Feng; Zhang, Lian-quan; Liu, Deng-cai; Mao, Long

    2015-06-01

    Bread wheat (or common wheat, Triticum aestivum) is an allohexaploid (AABBDD, 2n = 6x = 42) that arose by hybridization between a cultivated tetraploid wheat T. turgidum (AABB, 2n = 4x = 28) and the wild goatgrass Aegilops tauschii (DD, 2n = 2x = 14). Polyploidization provided niches for rigorous genome modification at cytogenetic, genetic, and epigenetic levels, rendering a broader spread than its progenitors. This review summarizes the latest advances in understanding gene regulation mechanisms in newly synthesized allohexaploid wheat and possible correlation with polyploid growth vigor and adaptation. Cytogenetic studies reveal persistent association of whole-chromosome aneuploidy with nascent allopolyploids, in contrast to the genetic stability in common wheat. Transcriptome analysis of the euploid wheat shows that small RNAs are driving forces for homoeo-allele expression regulation via genetic and epigenetic mechanisms. The ensuing non-additively expressed genes and those with expression level dominance to the respective progenitor may play distinct functions in growth vigor and adaptation in nascent allohexaploid wheat. Further genetic diploidization of allohexaploid wheat is not random. Regional asymmetrical gene distribution, rather than subgenome dominance, is observed in both synthetic and natural allohexaploid wheats. The combinatorial effects of diverged genomes, subsequent selection of specific gene categories, and subgenome-specific traits are essential for the successful establishment of common wheat. PMID:25747845

  1. PGSB PlantsDB: updates to the database framework for comparative plant genome research

    PubMed Central

    Spannagl, Manuel; Nussbaumer, Thomas; Bader, Kai C.; Martis, Mihaela M.; Seidel, Michael; Kugler, Karl G.; Gundlach, Heidrun; Mayer, Klaus F.X.

    2016-01-01

    PGSB (Plant Genome and Systems Biology: formerly MIPS) PlantsDB (http://pgsb.helmholtz-muenchen.de/plant/index.jsp) is a database framework for the comparative analysis and visualization of plant genome data. The resource has been updated with new data sets and types as well as specialized tools and interfaces to address user demands for intuitive access to complex plant genome data. In its latest incarnation, we have re-worked both the layout and navigation structure and implemented new keyword search options and a new BLAST sequence search functionality. Actively involved in corresponding sequencing consortia, PlantsDB has dedicated special efforts to the integration and visualization of complex triticeae genome data, especially for barley, wheat and rye. We enhanced CrowsNest, a tool to visualize syntenic relationships between genomes, with data from the wheat sub-genome progenitor Aegilops tauschii and added functionality to the PGSB RNASeqExpressionBrowser. GenomeZipper results were integrated for the genomes of barley, rye, wheat and perennial ryegrass and interactive access is granted through PlantsDB interfaces. Data exchange and cross-linking between PlantsDB and other plant genome databases is stimulated by the transPLANT project (http://transplantdb.eu/). PMID:26527721

  2. PGSB PlantsDB: updates to the database framework for comparative plant genome research.

    PubMed

    Spannagl, Manuel; Nussbaumer, Thomas; Bader, Kai C; Martis, Mihaela M; Seidel, Michael; Kugler, Karl G; Gundlach, Heidrun; Mayer, Klaus F X

    2016-01-01

    PGSB (Plant Genome and Systems Biology: formerly MIPS) PlantsDB (http://pgsb.helmholtz-muenchen.de/plant/index.jsp) is a database framework for the comparative analysis and visualization of plant genome data. The resource has been updated with new data sets and types as well as specialized tools and interfaces to address user demands for intuitive access to complex plant genome data. In its latest incarnation, we have re-worked both the layout and navigation structure and implemented new keyword search options and a new BLAST sequence search functionality. Actively involved in corresponding sequencing consortia, PlantsDB has dedicated special efforts to the integration and visualization of complex triticeae genome data, especially for barley, wheat and rye. We enhanced CrowsNest, a tool to visualize syntenic relationships between genomes, with data from the wheat sub-genome progenitor Aegilops tauschii and added functionality to the PGSB RNASeqExpressionBrowser. GenomeZipper results were integrated for the genomes of barley, rye, wheat and perennial ryegrass and interactive access is granted through PlantsDB interfaces. Data exchange and cross-linking between PlantsDB and other plant genome databases is stimulated by the transPLANT project (http://transplantdb.eu/). PMID:26527721

  3. Cell division and endoreduplication play important roles in stem swelling of tuber mustard (Brassica juncea Coss. var. tumida Tsen et Lee).

    PubMed

    Shi, H; Wang, L L; Sun, L T; Dong, L L; Liu, B; Chen, L P

    2012-11-01

    We investigated spatio-temporal variations in cell division and the occurrence of endoreduplication in cells of tuber mustard stems during development. Cells in the stem had 8C nuclei (C represents DNA content of a two haploid genome), since it is an allotetraploid species derived from diploid Brassica rapa (AA) and B. nigra (BB), thus indicating the occurrence of endoreduplication. Additionally, we observed a dynamic change of cell ploidy in different regions of the swollen stems, with a decrease in 4C proportion in P4-1 and a sharp increase in 8C cells that became the dominant cell type (86.33% at most) in the inner pith cells. Furthermore, cDNAs of 14 cell cycle genes and four cell expansion genes were cloned and their spatial transcripts analysed in order to understand their roles in stem development. The expression of most cell cycle genes peaked in regions of the outer pith (P2 or P3), some genes regulating S/G2 and G2/M (BjCDKB1;2, BjCYCB1;1 and BjCYCB1;2) significantly decrease in P5 and P6, while G1/S regulators (BjE2Fa, BjE2Fb and BjE2Fc) showed a relative high expression level in the inner pith (P5) where cells were undergoing endoreduplication. Coincidentally, BjXTH1and BjXTH2 were exclusively expressed in the endoreduplicated cells. Our results suggest that cells of outer pith regions (P2 and P3) mainly divide for cell proliferation, while cells of the inner pith expand through endoreduplication. Endoreduplication could trigger expression of BjXTH1 and BjXTH2 and thus function in cell expansion of the pith tissue. PMID:22639957

  4. The Center for Optimized Structural Studies (COSS) platform for automation in cloning, expression, and purification of single proteins and protein-protein complexes.

    PubMed

    Mlynek, Georg; Lehner, Anita; Neuhold, Jana; Leeb, Sarah; Kostan, Julius; Charnagalov, Alexej; Stolt-Bergner, Peggy; Djinović-Carugo, Kristina; Pinotsis, Nikos

    2014-06-01

    Expression in Escherichia coli represents the simplest and most cost effective means for the production of recombinant proteins. This is a routine task in structural biology and biochemistry where milligrams of the target protein are required in high purity and monodispersity. To achieve these criteria, the user often needs to screen several constructs in different expression and purification conditions in parallel. We describe a pipeline, implemented in the Center for Optimized Structural Studies, that enables the systematic screening of expression and purification conditions for recombinant proteins and relies on a series of logical decisions. We first use bioinformatics tools to design a series of protein fragments, which we clone in parallel, and subsequently screen in small scale for optimal expression and purification conditions. Based on a scoring system that assesses soluble expression, we then select the top ranking targets for large-scale purification. In the establishment of our pipeline, emphasis was put on streamlining the processes such that it can be easily but not necessarily automatized. In a typical run of about 2 weeks, we are able to prepare and perform small-scale expression screens for 20-100 different constructs followed by large-scale purification of at least 4-6 proteins. The major advantage of our approach is its flexibility, which allows for easy adoption, either partially or entirely, by any average hypothesis driven laboratory in a manual or robot-assisted manner. PMID:24647677

  5. Divergent distribution of the sensor kinase CosS in non-thermophilic Campylobacter species and its functional incompatibility with the Campylobacter jejuni CosR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two-component signal transduction system is commonly composed of a sensor histidine kinase and a response regulator, modulating gene expression in response to environmental changes through a phosphorylation-dependent process. CosR is an OmpR-type response regulator essential for the viability of Cam...

  6. UHPLC-PDA-ESI/HRMS/MSn analysis of anthocyanins, flavonol glycosides, and hydroxycinnamic acid derivatives in red mustard green (Brassica juncea (L) Coss variety)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An UHPLC-PDA-ESI/HRMS/MSn profiling method was used for a comprehensive study of the polyphenols in red mustard greens and identified 209 phenolic compounds: 67 anthocyanin, 102 flavonol glycosides, and 40 hydroxycinnamic acid derivatives. The glycosylation patterns of the flavonoids were assigned ...

  7. Impact of fermentation on phenolic compounds in leaves of pak choi (Brassica campestris L. ssp. chinensis var. communis) and Chinese leaf mustard (Brassica juncea coss).

    PubMed

    Harbaum, Britta; Hubbermann, Eva Maria; Zhu, Zhujun; Schwarz, Karin

    2008-01-01

    Four different cultivars of Chinese Brassica vegetables (two pak choi cultivars and two Chinese leaf mustard cultivars) were fermented according to a traditional Chinese method called pickling. The plant material was investigated before and after the fermentation procedure to determine the qualitative and quantitative changes in its polyphenols. A detailed description of the identified phenolic compounds of leaf mustard by HPLC-ESI-MS(n) is presented here for the first time, including hydroxycinnamic acid mono- and diglycosides (gentiobioses) and flavonoid tetraglycosides. Flavonoid derivatives with a lower molecular mass (di- and triglycosides) and aglycones of flavonoids and hydroxycinnamic acids were detected in fermented cabbages compared to the main compounds detected in nonfermented cabbages (tri- and tetraglycosides of flavonoids and hydroxycinnamic acid derivatives of malic acid, glycoside, and quinic acid). During the fermentation process, contents of flavonoid derivatives and some hydroxycinnamic acid derivatives were found to decrease. Some marginal losses of polyphenols were observed even in the kneading step of the plant material prior to the fermentation procedure. The antioxidative potential of fermented cabbages was much higher compared to that of nonfermented cabbages in the TEAC assay, but not observable in the DPPH assay. The increase of the antioxidative potential detected in the TEAC assay was attributed to the qualitative changes of polyphenols as well as other reductones potentially present. PMID:18078315

  8. [Detection of the introgression of genome elements of Aegilops cylindrica Host. into Triticum aestivum L. genome with ISSR-analysis].

    PubMed

    Galaev, A V; Babaiants, L T; Sivolap, Iu M

    2003-01-01

    Comparative analysis of introgressive and parental forms of wheat was carried out to reveal the sites of donor genome with new loci of resistance to fungal diseases. By ISSR-method 124 ISSR-loci were detected in the genomes of 18 individual plants of introgressive line 5/20-91; 17 of them have been related to introgressive fragments of Ae. cylindrica genome in T. aestivum. It was shown that ISSR-method is effective for detection of the variability caused by introgression of alien genetic material to T. aestivum genome. PMID:12945176

  9. CONSERVED REGULATOR ELEMENTS IDENTIFIED FROM A COMPARATIVE PUROINDOLINE GENE SEQUENCE SURVEY OF TRITICUM AND AEGILOPS DIPLOID TAXA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Kernel texture (“hardness”) is an important trait that determines end-use quality of wheat (Triticum aestivum L. and T. turgidum ssp. durum [Desf.] Husn.). Variation in texture is associated with the presence/absence or sequence polymorphism of two proteins, puroindoline a and puroindoline b. This...

  10. Genetic mapping of MlUM15: an Aegilops neglecta-derived powdery mildew resistance gene in common wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Powdery mildew, caused by Blumeria graminis DC f. sp. tritici, is a major fungal disease of wheat (Triticum aestivum L.) in cool and humid climates. Race-specific host plant resistance is a reliable, economical, and environmentally benign form of disease prevention. The identification of molecular m...

  11. Molecular and cytogenetic characterization of a durum wheat Aegilops speltoides chromosome translocation conferring resistance to stem rust

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stem rust is a serious disease of wheat that has caused historical epidemics, but it has not been a threat in recent decades in North America due to the eradication of the alternate host and deployment of resistant cultivars. However, the recent emergence of Ug99 (or race TTKS) poses a threat to glo...

  12. Mapping of novel powdery mildew resistance gene Pm53 introgressed from Aegilops speltoides into soft red winter wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Powdery mildew of wheat (Triticum aestivum L.) is a major fungal disease in many areas of the world, caused by Blumeria graminis f.sp. tritici (Bgt). Host plant resistance is the preferred form of disease prevention because it is both economical and environmentally benign. Identification of new resi...

  13. NADP-dependent aromatic alcohol dehydrogenase in polyploid wheats and their diploid relatives. On the origin and phylogeny of polyploid wheats.

    PubMed

    Jaaska, V

    1978-09-01

    The three major isoenzymes of the NADP-dependent aromatic alcohol dehydrogenase (ADH-B), distinguished in polyploid wheats by means of polyacrylamide gel electrophoresis, are shown to be coded by homoeoalleles of the locus Adh-2 on short arms of chromosomes of the fifth homoeologous group. Essentially codominant expression of the Adh-2 homoeolleles of composite genomes was observed in young seedlings of hexaploid wheats (T. aestivum s.l.) and tetraploid wheats of the emmer group (T. turgidum s.l.), whereas only the isoenzyme characteristic of the A genome is present in the seedlings of the timopheevii-group tetraploids (T. timopheevii s.str. and T. araraticum).The slowest-moving B(3) isoenzyme of polyploid wheats, coded by the homoeoallele of the B genome, is characteristic of the diploid species Aegilops speltoides S.l., including both its awned and awnless forms, but was not encountered in Ae. bicornis, Ae. sharonensis and Ae. longissima. The last two diploids, as well as Ae. tauschii, Ae. caudata, Triticum monococcum s.str., T. boeoticum s.l. (incl. T. thaoudar) and T. urartu all shared a common isoenzyme coinciding electrophoretically with the band B(2) controlled by the A and D genome homoeoalleles in polyploid wheats. Ae. bicomis is characterized by the slowest isoenzyme, B(4), not found in wheats and in the other diploid Aegilops species studied.Two electrophoretic variants of ADH-B, B(1) and B(2), considered to be alloenzymes of the A genome homoeoallele, were observed in T. dicoccoides, T. dicoccon, T. turgidum. s.str. and T. spelta, whereas B(2) was characteristic of T. timopheevii s.l. and only B(1) was found in the remaining taxa of polyploid wheats. The isoenzyme B(1), not encountered among diploid species, is considered to be a mutational derivative which arose on the tetraploid level from its more ancestral form B(2) characteristic of diploid wheats.The implication of the ADH-B isoenzyme data to the problems of wheat phylogeny and gene evolution is

  14. Sequencing of chloroplast genomes from wheat, barley, rye and their relatives provides a detailed insight into the evolution of the Triticeae tribe.

    PubMed

    Middleton, Christopher P; Senerchia, Natacha; Stein, Nils; Akhunov, Eduard D; Keller, Beat; Wicker, Thomas; Kilian, Benjamin

    2014-01-01

    Using Roche/454 technology, we sequenced the chloroplast genomes of 12 Triticeae species, including bread wheat, barley and rye, as well as the diploid progenitors and relatives of bread wheat Triticum urartu, Aegilops speltoides and Ae. tauschii. Two wild tetraploid taxa, Ae. cylindrica and Ae. geniculata, were also included. Additionally, we incorporated wild Einkorn wheat Triticum boeoticum and its domesticated form T. monococcum and two Hordeum spontaneum (wild barley) genotypes. Chloroplast genomes were used for overall sequence comparison, phylogenetic analysis and dating of divergence times. We estimate that barley diverged from rye and wheat approximately 8-9 million years ago (MYA). The genome donors of hexaploid wheat diverged between 2.1-2.9 MYA, while rye diverged from Triticum aestivum approximately 3-4 MYA, more recently than previously estimated. Interestingly, the A genome taxa T. boeoticum and T. urartu were estimated to have diverged approximately 570,000 years ago. As these two have a reproductive barrier, the divergence time estimate also provides an upper limit for the time required for the formation of a species boundary between the two. Furthermore, we conclusively show that the chloroplast genome of hexaploid wheat was contributed by the B genome donor and that this unknown species diverged from Ae. speltoides about 980,000 years ago. Additionally, sequence alignments identified a translocation of a chloroplast segment to the nuclear genome which is specific to the rye/wheat lineage. We propose the presented phylogeny and divergence time estimates as a reference framework for future studies on Triticeae. PMID:24614886

  15. Acc homoeoloci and the evolution of wheat genomes

    PubMed Central

    Chalupska, D.; Lee, H. Y.; Faris, J. D.; Evrard, A.; Chalhoub, B.; Haselkorn, R.; Gornicki, P.

    2008-01-01

    The DNA sequences of wheat Acc-1 and Acc-2 loci, encoding the plastid and cytosolic forms of the enzyme acetyl-CoA carboxylase, were analyzed with a view to understanding the evolution of these genes and the origin of the three genomes in modern hexaploid wheat. Acc-1 and Acc-2 loci from each of the wheats Triticum urartu (A genome), Aegilops tauschii (D genome), Triticum turgidum (AB genome), and Triticum aestivum (ABD genome), as well as two Acc-2-related pseudogenes from T. urartu were sequenced. The 2.3–2.4 Mya divergence time calculated here for the three homoeologous chromosomes, on the basis of coding and intron sequences of the Acc-1 genes, is at the low end of other estimates. Our clock was calibrated by using 60 Mya for the divergence between wheat and maize. On the same time scale, wheat and barley diverged 11.6 Mya, based on sequences of Acc and other genes. The regions flanking the Acc genes are not conserved among the A, B, and D genomes. They are conserved when comparing homoeologous genomes of diploid, tetraploid, and hexaploid wheats. Substitution rates in intergenic regions consisting primarily of repetitive sequences vary substantially along the loci and on average are 3.5-fold higher than the Acc intron substitution rates. The composition of the Acc homoeoloci suggests haplotype divergence exceeding in some cases 0.5 Mya. Such variation might result in a significant overestimate of the time since tetraploid wheat formation, which occurred no more than 0.5 Mya. PMID:18599450

  16. Characterizing the composition and evolution of homoeologous genomes in hexaploid wheat through BAC-end sequencing on chromosome 3B.

    PubMed

    Paux, Etienne; Roger, Delphine; Badaeva, Ekatherina; Gay, Georges; Bernard, Michel; Sourdille, Pierre; Feuillet, Catherine

    2006-11-01

    Bread wheat (Triticum aestivum) is one of the most important crops worldwide. However, because of its large, hexaploid, highly repetitive genome it is a challenge to develop efficient means for molecular analysis and genetic improvement in wheat. To better understand the composition and molecular evolution of the hexaploid wheat homoeologous genomes and to evaluate the potential of BAC-end sequences (BES) for marker development, we have followed a chromosome-specific strategy and generated 11 Mb of random BES from chromosome 3B, the largest chromosome of bread wheat. The sequence consisted of about 86% of repetitive elements, 1.2% of coding regions, and 13% remained unknown. With 1.2% of the sequence length corresponding to coding sequences, 6000 genes were estimated for chromosome 3B. New repetitive sequences were identified, including a Triticineae-specific tandem repeat (Fat) that represents 0.6% of the B-genome and has been differentially amplified in the homoeologous genomes before polyploidization. About 10% of the BES contained junctions between nested transposable elements that were used to develop chromosome-specific markers for physical and genetic mapping. Finally, sequence comparison with 2.9 Mb of random sequences from the D-genome of Aegilops tauschii suggested that the larger size of the B-genome is due to a higher content in repetitive elements. It also indicated which families of transposable elements are mostly responsible for differential expansion of the homoeologous wheat genomes during evolution. Our data demonstrate that BAC-end sequencing from flow-sorted chromosomes is a powerful tool for analysing the structure and evolution of polyploid and highly repetitive genomes. PMID:17010109

  17. Acc homoeoloci and the evolution of wheat genomes.

    PubMed

    Chalupska, D; Lee, H Y; Faris, J D; Evrard, A; Chalhoub, B; Haselkorn, R; Gornicki, P

    2008-07-15

    The DNA sequences of wheat Acc-1 and Acc-2 loci, encoding the plastid and cytosolic forms of the enzyme acetyl-CoA carboxylase, were analyzed with a view to understanding the evolution of these genes and the origin of the three genomes in modern hexaploid wheat. Acc-1 and Acc-2 loci from each of the wheats Triticum urartu (A genome), Aegilops tauschii (D genome), Triticum turgidum (AB genome), and Triticum aestivum (ABD genome), as well as two Acc-2-related pseudogenes from T. urartu were sequenced. The 2.3-2.4 Mya divergence time calculated here for the three homoeologous chromosomes, on the basis of coding and intron sequences of the Acc-1 genes, is at the low end of other estimates. Our clock was calibrated by using 60 Mya for the divergence between wheat and maize. On the same time scale, wheat and barley diverged 11.6 Mya, based on sequences of Acc and other genes. The regions flanking the Acc genes are not conserved among the A, B, and D genomes. They are conserved when comparing homoeologous genomes of diploid, tetraploid, and hexaploid wheats. Substitution rates in intergenic regions consisting primarily of repetitive sequences vary substantially along the loci and on average are 3.5-fold higher than the Acc intron substitution rates. The composition of the Acc homoeoloci suggests haplotype divergence exceeding in some cases 0.5 Mya. Such variation might result in a significant overestimate of the time since tetraploid wheat formation, which occurred no more than 0.5 Mya. PMID:18599450

  18. Genome wide identification of C1-2i zinc finger proteins and their response to abiotic stress in hexaploid wheat.

    PubMed

    Cheuk, Arnaud; Houde, Mario

    2016-04-01

    The C1-2i wheat Q-type C2H2 zinc finger protein (ZFP) transcription factor subclass has been reported to play important roles in plant stress responses. This subclass of ZFPs has not been studied in hexaploid wheat (Triticum aestivum) and we aimed to identify all members of this subclass and evaluate their responses to different abiotic stresses causing oxidative stress. Exploiting the recently published wheat draft genome sequence, we identified 53 members (including homoeologs from A, B and D genomes) of the C1-2i wheat Q-type C2H2 ZFPs (TaZFPs) representing 21 genes. Evolution analysis revealed that 9 TaZFPs members are directly inherited from the parents Triticum urartu and Aegilops tauschii, while 15 diverged through neoploidization events. This TaZFP subclass is responsive to the oxidative stress generator H2O2 and to high light, drought stress and flooding. Most TaZFPs are responsive to H2O2 (37/53), high light (44/53), flooding (31/53) or drought (37/53); 32 TaZFPs were up-regulated by at least 3 stresses and 16 were responsive to all stresses tested. A large number of these TaZFPs were physically mapped on different wheat draft genome sequences with known markers useful for QTL mapping. Our results show that the C1-2i subclass of TaZFPs is associated with responses to different abiotic stresses and that most TaZFPs (30/53 or 57 %) are located on group 5 chromosomes known to be involved in environment adaptation. Detailed characterization of these novel wheat TaZFPs and their association to QTL or eQTL may help to design wheat cultivars with improved tolerance to abiotic stress. PMID:26638714

  19. Fast-forward genetics by radiation hybrids to saturate the locus regulating nuclear-cytoplasmic compatibility in Triticum.

    PubMed

    Bassi, Filippo M; Ghavami, Farhad; Hayden, Matthew J; Wang, Yi; Forrest, Kerrie L; Kong, Stephan; Dizon, Rhoderissa; Michalak de Jimenez, Monika K; Meinhardt, Steven W; Mergoum, Mohamed; Gu, Yong Q; Kianian, Shahryar F

    2016-08-01

    The nuclear-encoded species cytoplasm specific (scs) genes control nuclear-cytoplasmic compatibility in wheat (genus Triticum). Alloplasmic cells, which have nucleus and cytoplasm derived from different species, produce vigorous and vital organisms only when the correct version of scs is present in their nucleus. In this study, bulks of in vivo radiation hybrids segregating for the scs phenotype have been genotyped by sequencing with over 1.9 million markers. The high marker saturation obtained for a critical region of chromosome 1D allowed identification of 3318 reads that mapped in close proximity of the scs. A novel in silico approach was deployed to extend these short reads to sequences of up to 70 Kb in length and identify candidate open reading frames (ORFs). Markers were developed to anchor the short contigs containing ORFs to a radiation hybrid map of 650 individuals with resolution of 288 Kb. The region containing the scs locus was narrowed to a single Bacterial Artificial Chromosome (BAC) contig of Aegilops tauschii. Its sequencing and assembly by nano-mapping allowed rapid identification of a rhomboid gene as the only ORF existing within the refined scs locus. Resequencing of this gene from multiple germplasm sources identified a single nucleotide mutation, which gives rise to a functional amino acid change. Gene expression characterization revealed that an active copy of this rhomboid exists on all homoeologous chromosomes of wheat, and depending on the specific cytoplasm each copy is preferentially expressed. Therefore, a new methodology was applied to unique genetic stocks to rapidly identify a strong candidate gene for the control of nuclear-cytoplasmic compatibility in wheat. PMID:26915753

  20. High mature grain phytase activity in the Triticeae has evolved by duplication followed by neofunctionalization of the purple acid phosphatase phytase (PAPhy) gene

    PubMed Central

    Brinch-Pedersen, Henrik

    2013-01-01

    The phytase activity in food and feedstuffs is an important nutritional parameter. Members of the Triticeae tribe accumulate purple acid phosphatase phytases (PAPhy) during grain filling. This accumulation elevates mature grain phytase activities (MGPA) up to levels between ~650 FTU/kg for barley and 6000 FTU/kg for rye. This is notably more than other cereals. For instance, rice, maize, and oat have MGPAs below 100 FTU/kg. The cloning and characterization of the PAPhy gene complement from wheat, barley, rye, einkorn, and Aegilops tauschii is reported here. The Triticeae PAPhy genes generally consist of a set of paralogues, PAPhy_a and PAPhy_b, and have been mapped to Triticeae chromosomes 5 and 3, respectively. The promoters share a conserved core but the PAPhy_a promoter have acquired a novel cis-acting regulatory element for expression during grain filling while the PAPhy_b promoter has maintained the archaic function and drives expression during germination. Brachypodium is the only sequenced Poaceae sharing the PAPhy duplication. As for the Triticeae, the duplication is reflected in a high MGPA of ~4200 FTU/kg in Brachypodium. The sequence conservation of the paralogous loci on Brachypodium chromosomes 1 and 2 does not extend beyond the PAPhy gene. The results indicate that a single-gene segmental duplication may have enabled the evolution of high MGPA by creating functional redundancy of the parent PAPhy gene. This implies that similar MGPA levels may be out of reach in breeding programs for some Poaceae, e.g. maize and rice, whereas Triticeae breeders should focus on PAPhy_a. PMID:23918958

  1. Analysis of ATP6 sequence diversity in the Triticum-Aegilops group of species reveals the crucial role of rearrangement in mitochondrial genome evolution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mutation and chromosomal rearrangements are the two main forces of increasing genetic diversity for natural selection to act upon, and ultimately drive the evolutionary process. Although genome evolution is a function of both forces, simultaneously, the ratio of each can be varied among different ge...

  2. Test Review: Abikoff, H., & Gallagher, R. (2009). "Children's Organizational Skills Scales." North Tonawanda, NY: Multi-Health Systems

    ERIC Educational Resources Information Center

    Kaya, Fatih; Delen, Erhan; Ritter, Nicola L.

    2012-01-01

    This article presents a review of the Children's Organizational Skills Scales (COSS) which were designed to assess how children organize their time, materials, and actions to accomplish important tasks at home and school. The scale quantifies children's skills in organization, time management, and planning (OTMP). The COSS is a multi-informant…

  3. Pheromone and host odor attractants for managing Diorhabda spp.: Biological control agents of saltcedar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The recent identification of the aggregation pheromone (Cossé et al., 2005, Journal of Chemical Ecology 26:1735-1748), and host odor attractant (Cossé et al., 2005, Journal of Chemical Ecology, in press) for the leaf beetle Diorhabda elongata, a biological control agent of saltcedar, allowed for a m...

  4. 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

  5. RFLP-based analysis of three RbcS subfamilies in diploid and polyploid species of wheat.

    PubMed

    Galili, S; Avivi, Y; Millet, E; Feldman, M

    2000-05-01

    The RbcS multigene family of hexaploid (bread) wheat, Triticum aestivum (genome BBAADD), which encodes the small subunit of Rubisco, comprises at least 22 genes. Based on their 3' non-coding sequences, these genes have been classified into four subfamilies (SFs), of which three (SF-2, SF-3 and SF-4) are located on chromosomes of homoeologous group 2 and one (SF-1) on homoeologous group 5. In the present study we hybridized three RbcS subfamily-specific probes (for SF-1, SF-2 and SF-3) to total DNA digested with four restriction enzymes and analyzed the RFLP patterns of these subfamilies in eight diploid species of Aegilops and Triticum, and in two tetraploid and one hexaploid species of wheat (the diploid species are the putative progenitors of the polyploid wheats). The three subfamilies varied in their level of polymorphism, with SF-2 being the most polymorphic in all species. In the diploids, the order of polymorphism was SF-2 > SF-3 > SF-1, and in the polyploids SF-2 > SF-1 > SF-3. The RbcS genes of the conserved SF-1 were previously reported to have the highest expression levels in all the wheat tissues studied, indicating a negative correlation between polymorphism and gene expression. Among the diploids, the species with the D and the S genomes were the most polymorphic and the A-genome species were the least polymorphic. The polyploids were less polymorphic than the diploids. Within the polyploids, the A genome was somewhat more polymorphic than the B genome, while the D genome was the most conserved. Among the diploid species with the A genome, the RFLP pattern of T. urartu was closer to that of the A genome of the common wheat cultivar Chinese Spring (CS) than to that of T. monococcum. The pattern in Ae. tauschii was similar to that of the D genome of CS. Only partial resemblance was found between the RFLP patterns of the species with the S genome and the B genome of CS. PMID:10852490

  6. Renin inhibition activity by chitooligosaccharides.

    PubMed

    Park, Pyo-Jam; Ahn, Chang-Bum; Jeon, You-Jin; Je, Jae-Young

    2008-04-01

    Six kinds of chitooligosaccharides (COSs) with different molecular weight (MW) and degree of deacetylation (DD) were prepared using ultrafiltration membrane reactor, and their renin inhibition modes were evaluated. All the COSs showed the renin-inhibitory activities with dose-dependent manner, and 90-COSs had the potent renin-inhibitory activity than that of 50-COSs. Among them, 90-MMWCOS (1000-5000Da) exhibits the highest activity with IC(50) value of 0.51mg/mL and acts as competitive inhibitor with K(i) value of 0.28mg/mL by Lineweaver-Burk and Dixon plots. These results indicated that DD value and MW of COSs are important factors affecting renin-inhibitory activity. PMID:18313296

  7. [Molecular-genetic analysis of wheat (T. aestivum L.) genome with introgression of Ae. cylindrica Host genetic elements].

    PubMed

    Galaev, A V; Sivolap, Iu M

    2005-01-01

    Wheat-aegilops hybrid plants Triticum aestivum L. (2n = 42) x Aegilops cylindrica Host (2n = 28) were investigated with using microsatellite markers. In two BC1F9 lines some genome modifications connected with losing DNA fragments of initial variety or appearing of Aegilops genome elements were detected. In some investigated hybrids new amplicons lacking in parental plants were found. Substitution of wheat chromosomes for aegilops chromosomes was not revealed. Analysis of microsatellite loci in BC2F5 plants showed stable introgression of aegilops genetic elements into wheat; elimination of some transferred aegilops DNA fragments in the course of backcrossing; decreasing size of introgressive elements after backcrossing. Introgressive lines were classified according to genome changes. PMID:16250247

  8. Cellobiohydrolases Produce Different Oligosaccharides from Chitosan.

    PubMed

    Tegl, Gregor; Öhlknecht, Christoph; Vielnascher, Robert; Rollett, Alexandra; Hofinger-Horvath, Andreas; Kosma, Paul; Guebitz, Georg M

    2016-06-13

    Chito-oligosaccharides (COSs) are bioactive molecules with interesting characteristics; however, their exploitation is still restricted due to limited amounts accessible with current production strategies. Here we present a strategy for the production of COSs based on hydrolysis of chitosan by using readily available glycosidases. Cellobiohydrolases (EC 3.2.1.91) were compared with chitosanases (EC 3.2.1.132) regarding their ability for COS production, and the resulting fractions were analyzed by MS and NMR. The oligosaccharides had a degree of polymerization between three and six units, and the degree of acetylation (DA) varied depending on the applied enzyme. Different cellobiohydrolases produced COSs with varying DA, and based on comprehensive NMR analysis the preferred cleavage sites of the respective enzymes that show chitosanase and chitinase activity were elucidated. The study reveals the high potential of readily available cellulolytic enzymes besides chitosanases for the production of COSs with distinct structure facilitating access to this bioactive compound class. PMID:27214513

  9. 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

  10. The Harmonizing Outcome Measures for Eczema (HOME) roadmap: a methodological framework to develop core sets of outcome measurements in dermatology.

    PubMed

    Schmitt, Jochen; Apfelbacher, Christian; Spuls, Phyllis I; Thomas, Kim S; Simpson, Eric L; Furue, Masutaka; Chalmers, Joanne; Williams, Hywel C

    2015-01-01

    Core outcome sets (COSs) are consensus-derived minimum sets of outcomes to be assessed in a specific situation. COSs are being increasingly developed to limit outcome-reporting bias, allow comparisons across trials, and strengthen clinical decision making. Despite the increasing interest in outcomes research, methods to develop COSs have not yet been standardized. The aim of this paper is to present the Harmonizing Outcomes Measures for Eczema (HOME) roadmap for the development and implementation of COSs, which was developed on the basis of our experience in the standardization of outcome measurements for atopic eczema. Following the establishment of a panel representing all relevant stakeholders and a research team experienced in outcomes research, the scope and setting of the core set should be defined. The next steps are the definition of a core set of outcome domains such as symptoms or quality of life, followed by the identification or development and validation of appropriate outcome measurement instruments to measure these core domains. Finally, the consented COS needs to be disseminated, implemented, and reviewed. We believe that the HOME roadmap is a useful methodological framework to develop COSs in dermatology, with the ultimate goal of better decision making and promoting patient-centered health care. PMID:25186228

  11. Computerized Operator Support System – Phase II Development

    SciTech Connect

    Ulrich, Thomas A.; Boring, Ronald L.; Lew, Roger T.; Thomas, Kenneth D.

    2015-02-01

    A computerized operator support system (COSS) prototype for nuclear control room process control is proposed and discussed. The COSS aids operators in addressing rapid plant upsets that would otherwise result in the shutdown of the power plant and interrupt electrical power generation, representing significant costs to the owning utility. In its current stage of development the prototype demonstrates four advanced functions operators can use to more efficiently monitor and control the plant. These advanced functions consist of: (1) a synthesized and intuitive high level overview display of system components and interrelations, (2) an enthalpy-based mathematical chemical and volume control system (CVCS) model to detect and diagnose component failures, (3) recommended strategies to mitigate component failure effects and return the plant back to pre-fault status, and (4) computer-based procedures to walk the operator through the recommended mitigation actions. The COSS was demonstrated to a group of operators and their feedback was collected. The operators responded positively to the COSS capabilities and features and indicated the system would be an effective operator aid. The operators also suggested several additional features and capabilities for the next iteration of development. Future versions of the COSS prototype will include additional plant systems, flexible computer-based procedure presentation formats, and support for simultaneous component fault diagnosis and dual fault synergistic mitigation action strategies to more efficiently arrest any plant upsets.

  12. Cube-octameric silsesquioxane-mediated cargo peptide delivery into living cancer cells.

    PubMed

    Hörner, Sebastian; Fabritz, Sebastian; Herce, Henry D; Avrutina, Olga; Dietz, Christian; Stark, Robert W; Cardoso, M Cristina; Kolmar, Harald

    2013-04-14

    Cube octameric silsesquioxanes (COSS) are among the smallest nanoparticles known to date with a diameter of only 0.7 nm. We describe a COSS-based delivery system which allows for the drug targeting in human cells. It comprises a siloxane core with seven pendant aminopropyl groups and a fluorescently labeled peptidic ligand attached to one cage corner via a reversible disulfide bond to ensure its intracellular release. Bimodal amplitude-modulated atomic force microscopy (AFM) experiments revealed the formation of dendritic COSS structures by a self-assembly of single particles on negatively charged surfaces. Nuclear targeting was demonstrated in HeLa cells by selective binding of released p21(Cip1/Waf1)-derived cargo peptide to PCNA, a protein involved in DNA replication and repair. PMID:23250285

  13. A COMPUTERIZED OPERATOR SUPPORT SYSTEM PROTOTYPE

    SciTech Connect

    Thomas A. Ulrich; Roger Lew; Ronald L. Boring; Ken Thomas

    2015-03-01

    A computerized operator support system (COSS) is proposed for use in nuclear power plants to assist control room operators in addressing time-critical plant upsets. A COSS is a collection of technologies to assist operators in monitoring overall plant performance and making timely, informed decisions on appropriate control actions for the projected plant condition. A prototype COSS was developed in order to demonstrate the concept and provide a test bed for further research. The prototype is based on four underlying elements consisting of a digital alarm system, computer-based procedures, piping and instrumentation diagram system representations, and a recommender module for mitigation actions. The initial version of the prototype is now operational at the Idaho National Laboratory using the Human System Simulation Laboratory.

  14. Remediating Organizational Functioning in Children with ADHD: Immediate and Long-Term Effects from a Randomized Controlled Trial

    PubMed Central

    Abikoff, Howard; Gallagher, Richard; Wells, Karen C.; Murray, Desiree W.; Huang, Lei; Lu, Feihan; Petkova, Eva

    2012-01-01

    Objective The study compared the efficacy of two behavioral interventions to ameliorate organization, time management and planning (OTMP) difficulties in 3rd–5th grade children with Attention-Deficit/Hyperactivity Disorder (ADHD). Method In a dual-site randomized controlled trial, 158 children were assigned to Organizational Skills Training (OST, N=64); “PATHKO”, a performance-based intervention that precluded skills training (N=61); or a wait-list control (WL, N=33). Treatments were 20 individual clinic-based sessions over 10–12 weeks. OST involved skills building provided primarily to the child. PATHKO trained parents and teachers to reinforce children contingently for meeting end-point target goals. Primary outcomes were the Children’s Organizational Skills Scales (COSS-Parent, COSS-Teacher). Other relevant functional outcomes were assessed. Percentage of participants no longer meeting inclusion criteria for OTMP impairments informed on clinical significance. Assessments occurred at post-treatment, 1-month post-treatment, and twice in the following school year. Results OST was superior to WL on the COSS-P (Cohen’s d = 2.77; p< .0001), COSS-T (d = 1.18; p< .0001), children’s COSS self-ratings, academic performance and proficiency, homework, and family functioning. OST was significantly better than PATHKO only on the COSS-P (d = .63; p< .005). PATHKO was superior to WL on most outcomes, but not in academic proficiency. 60% of OST and PATHKO participants no longer met OTMP inclusion criteria vs. 3% of controls. Significant maintenance effects were found for both treatments. Conclusions Two distinct treatments targeting OTMP problems in children with ADHD generated robust, sustained functional improvements. The interventions show promise of clinical utility in children with ADHD and organizational deficits. PMID:22889336

  15. Human Factors and Technical Considerations for a Computerized Operator Support System Prototype

    SciTech Connect

    Ulrich, Thomas Anthony; Lew, Roger Thomas; Medema, Heather Dawne; Boring, Ronald Laurids; Thomas, Kenneth David

    2015-09-01

    A prototype computerized operator support system (COSS) has been developed in order to demonstrate the concept and provide a test bed for further research. The prototype is based on four underlying elements consisting of a digital alarm system, computer-based procedures, PI&D system representations, and a recommender module for mitigation actions. At this point, the prototype simulates an interface to a sensor validation module and a fault diagnosis module. These two modules will be fully integrated in the next version of the prototype. The initial version of the prototype is now operational at the Idaho National Laboratory using the U.S. Department of Energy’s Light Water Reactor Sustainability (LWRS) Human Systems Simulation Laboratory (HSSL). The HSSL is a full-scope, full-scale glass top simulator capable of simulating existing and future nuclear power plant main control rooms. The COSS is interfaced to the Generic Pressurized Water Reactor (gPWR) simulator with industry-typical control board layouts. The glass top panels display realistic images of the control boards that can be operated by touch gestures. A section of the simulated control board was dedicated to the COSS human-system interface (HSI), which resulted in a seamless integration of the COSS into the normal control room environment. A COSS demonstration scenario has been developed for the prototype involving the Chemical & Volume Control System (CVCS) of the PWR simulator. It involves a primary coolant leak outside of containment that would require tripping the reactor if not mitigated in a very short timeframe. The COSS prototype presents a series of operator screens that provide the needed information and soft controls to successfully mitigate the event.

  16. Core Outcome Sets and Multidimensional Assessment Tools for Harmonizing Outcome Measure in Chronic Pain and Back Pain.

    PubMed

    Kaiser, Ulrike; Neustadt, Katrin; Kopkow, Christian; Schmitt, Jochen; Sabatowski, Rainer

    2016-01-01

    Core Outcome Sets (COSs) are a set of domains and measurement instruments recommended for application in any clinical trial to ensure comparable outcome assessment (both domains and instruments). COSs are not exclusively recommended for clinical trials, but also for daily record keeping in routine care. There are several COS recommendations considering clinical trials as well as multidimensional assessment tools to support daily record keeping in low back pain. In this article, relevant initiatives will be described, and implications for research in COS development in chronic pain and back pain will be discussed. PMID:27589816

  17. 15 CFR 23.2 - Contact person.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Contact person. 23.2 Section 23.2 Commerce and Foreign Trade Office of the Secretary of Commerce USE OF PENALTY MAIL IN THE LOCATION AND RECOVERY OF MISSING CHILDREN § 23.2 Contact person. Tim Coss, Office of Administrative Services...

  18. 77 FR 5177 - Schedule of Fees for Consular Services, Department of State and Overseas Embassies and Consulates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-02

    ... referred to as the Cost of Service Study or ``CoSS,'' which is the activity-based costing model that the... published a proposed rule in the Federal Register, 75 FR 6321, on February 9, 2010, proposing to amend... supplementary notice in the Federal Register, 75 FR 14111, on March 24, 2010 (Public Notice 6928)....

  19. 75 FR 14111 - Schedule of Fees for Consular Services, Department of State and Overseas Embassies and Consulates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-24

    ... information regarding the Cost of Survey Study (CoSS), the activity-based costing model that the Department... additional written detail below. Additional Detail on the Cost of Service Study Activity-Based Costing... Department chose to develop and use an activity-based costing (ABC) model to determine the true cost of...

  20. 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...

  1. Physical mapping of a large plant genome using global high-information content fingerprinting: a distal region of wheat 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 wheat. We report the use of the Ae. tauschii, the diploid ancestor of the wheat D genome, for the construction of t...

  2. First detection in North America of virulence in Puccinia triticina to wheat seedlings with Lr21

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaf rust resistance gene Lr21 is present in hard red spring wheat (Triticum aestivum) cultivars grown in Minnesota, North Dakota, South Dakota, Manitoba and Saskatchewan. Lr21 was originally derived from the wild wheat relative T. tauschii. Isolates of Puccinia triticina, the causal organism of whe...

  3. Association between simple sequence repeat-rich chromosome regions and intergenomic translocation breakpoints in natural populations of allopolyploid wild wheats

    PubMed Central

    Molnár, István; Cifuentes, Marta; Schneider, Annamária; Benavente, Elena; Molnár-Láng, Márta

    2011-01-01

    Background and Aims Repetitive DNA sequences are thought to be involved in the formation of chromosomal rearrangements. The aim of this study was to analyse the distribution of microsatellite clusters in Aegilops biuncialis and Aegilops geniculata, and its relationship with the intergenomic translocations in these allotetraploid species, wild genetic resources for wheat improvement. Methods The chromosomal localization of (ACG)n and (GAA)n microsatellite sequences in Ae. biuncialis and Ae. geniculata and in their diploid progenitors Aegilops comosa and Aegilops umbellulata was investigated by sequential in situ hybridization with simple sequence repeat (SSR) probes and repeated DNA probes (pSc119·2, Afa family and pTa71) and by dual-colour genomic in situ hybridization (GISH). Thirty-two Ae. biuncialis and 19 Ae. geniculata accessions were screened by GISH for intergenomic translocations, which were further characterized by fluorescence in situ hybridization and GISH. Key Results Single pericentromeric (ACG)n signals were localized on most U and on some M genome chromosomes, whereas strong pericentromeric and several intercalary and telomeric (GAA)n sites were observed on the Aegilops chromosomes. Three Ae. biuncialis accessions carried 7Ub–7Mb reciprocal translocations and one had a 7Ub–1Mb rearrangement, while two Ae. geniculata accessions carried 7Ug–1Mg or 5Ug–5Mg translocations. Conspicuous (ACG)n and/or (GAA)n clusters were located near the translocation breakpoints in eight of the ten translocated chromosomes analysed, SSR bands and breakpoints being statistically located at the same chromosomal site in six of them. Conclusions Intergenomic translocation breakpoints are frequently mapped to SSR-rich chromosomal regions in the allopolyploid species examined, suggesting that microsatellite repeated DNA sequences might facilitate the formation of those chromosomal rearrangements. The (ACG)n and (GAA)n SSR motifs serve as additional chromosome markers

  4. Weed-suppressive bacteria to reduce annual grass weeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cheatgrass (Bromus tectorum L.), medusahead (Taeniatherum caput-medusae [L.] Nevski) and jointed goatgrass (Aegilops cylindrica L.) are exotic, annual grasses that negatively affect cereal production in cropland; reduce protein-rich forage for cattle; choke out native plants in the shrub-steppe habi...

  5. Targeted introgression of a wheat stem rust resistance gene by DNA marker-assisted chromosome engineering genetics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In wheat (Triticum aestivum L.), stem rust resistance gene Sr39, derived from Aegilops speltoides Tausch, is highly resistant to multiple stem rust races including TTKSK (Ug99). However, the gene has not been used in wheat breeding because of linkage drag associated with the large 2S chromosome segm...

  6. Development of a PCR Assay and Marker-Assisted Transfer of Leaf Rust and Stripe Rust Resistance Genes Lr57 and Yr40 into Hard Red Winter Wheats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The wheat (Triticum aestivum L.)-Aegilops geniculata introgression T5DL·5DS-5MgS (0.95), with stripe rust resistance gene Yr40 and leaf rust resistance gene Lr57, is an effective source of resistance against most isolates of the rust pathogen in Kansas and India. Rust resistance genes Lr57 and Yr40 ...

  7. Synthesis and characterization of advanced durum wheat hybrids and addition lines with thinopyrum chromosomes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Durum wheat (Triticum turgidum L., 2n = 4x = 28; AABB genomes) is a natural hybrid – an allotetraploid between two wild species, Triticum urartu Tumanian (AA genome) and Aegilops speltoides Tausch (BB genome). As shown earlier, even at the allotetraploid level, durum wheat can tolerate chromosomal ...

  8. Economics of alternative management practices for jointed goatgrass in winter wheat in the Pacific Northwest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Jointed goatgrass (JGG) (Aegilops cylindrica) is an invasive annual grass weed that reduces winter wheat yield and quality. In the past 20 to 30 years, there has been much research conducted on jointed goatgrass; however, there has never been an empirical economic evaluation of jointed goatgrass in ...

  9. Accelerated evolution of the mitochondrial genome in an alloplasmic line of durum wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat is not only an important crop but also an excellent plant species for nuclear mitochondrial interaction studies. To investigate the level of sequence changes introduced into the mitochondrial genome under the alloplasmic conditions, three mitochondrial genomes of Triticum-Aegilops species w...

  10. Identification of a candidate gene for the wheat endopeptidase Ep-D1 locus and two other STS markers linked to the eyespot resistance gene Pch1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat is prone to strawbreaker foot rot (eye- spot), a fungal disease caused by Oculimacula yallundae and O. acuformis. The most effective source of genetic resistance is Pch1, a gene derived from Aegilops ventri- cosa. The endopeptidase isozyme marker allele Ep-D1b, linked to Pch1, has been shown t...