The efficacy of Cot-based gene enrichment in wheat (Triticum aestivum L.)

We report the results of a study on the effectiveness of Cot filtration (CF) in the characterization of the gene space of bread wheat (Triticum aestivum L.), a large genome species (1C = 16 700 Mb) of tremendous agronomic importance. Using published Cot data as a guide, 2 genomic libraries for hexaploid wheat were constructed from the single-stranded DNA collected at Cot values > 1188 and 1639 M·s. Compared with sequences from a whole genome shotgun library from Aegilops tauschii (the D genome donor of bread wheat), the CF libraries exhibited 13.7-fold enrichment in genes, 5.8-fold enrichment in unknown low-copy sequences, and a 3-fold reduction in repetitive DNA. CF is twice as efficient as methylation filtration at enriching wheat genes. This research suggests that, with improvements, CF will be a highly useful tool in sequencing the gene space of wheat.Key words: gene enrichment, renaturation kinetics, gene-rich regions, bread wheat.

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Allelic variation and composition of HMW-GS in advanced lines derived from d-genome synthetic hexaploid / bread wheat (Triticum aestivum L.)

Journal of Crop Science and Biotechnology ◽

10.1007/s12892-011-0088-1 ◽

2012 ◽

Vol 15 (1) ◽

pp. 1-7 ◽

Cited By ~ 5

Author(s):

Awais Rasheed ◽

Tariq Mahmood ◽

Alvina Gul Kazi ◽

Abdul Ghafoor ◽

Abdul Mujeeb-Kazi

Keyword(s):

Triticum Aestivum ◽

Bread Wheat ◽

Allelic Variation ◽

Triticum Aestivum L ◽

D Genome ◽

Synthetic Hexaploid

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

Genome ◽

10.1139/g09-033 ◽

2009 ◽

Vol 52 (6) ◽

pp. 576-587 ◽

Cited By ~ 45

Author(s):

Humphrey Wanjugi ◽

Devin Coleman-Derr ◽

Naxin Huo ◽

Shahryar F. Kianian ◽

Ming-Cheng Luo ◽

...

Keyword(s):

Triticum Aestivum ◽

Transposable Elements ◽

Repetitive Dna ◽

Hexaploid Wheat ◽

Rapid Development ◽

Aegilops Tauschii ◽

Triticum Aestivum L ◽

Dynamic Evolution ◽

D Genome ◽

Repeat Dna

In hexaploid wheat ( Triticum aestivum L.) (AABBDD, C = 17 000 Mb), repeat DNA accounts for ∼90% of the genome, of which transposable elements (TEs) constitute 60%–80%. Despite the dynamic evolution of TEs, our previous study indicated that the majority of TEs are conserved and collinear between the homologous wheat genomes, based on identical insertion patterns. In this study, we exploited the unique and abundant TE insertion junction regions identified from diploid Aegilops tauschii to develop genome-specific repeat DNA junction markers (RJM) for use in hexaploid wheat. In this study, both BAC end and random shotgun sequences were used to search for RJM. Of the 300 RJM primer pairs tested, 269 (90%) amplified single bands from diploid Ae. tauschii. Of these 269 primer pairs, 260 (97%) amplified hexaploid wheat and 9 (3%) amplified Ae. tauschii only. Among the RJM primers that amplified hexaploid wheat, 88% were successfully assigned to individual chromosomes of the hexaploid D genome. Among the 38 RJM primers mapped on chromosome 6D, 31 (82%) were unambiguously mapped to delineated bins of the chromosome using various wheat deletion lines. Our results suggest that the unique RJM derived from the diploid D genome could facilitate genetic, physical, and radiation mapping of the hexaploid wheat D genome.

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The first near-complete assembly of the hexaploid bread wheat genome, Triticum aestivum

10.1101/159111 ◽

2017 ◽

Cited By ~ 5

Author(s):

Aleksey V. Zimin ◽

Daniela Puiu ◽

Richard Hall ◽

Sarah Kingan ◽

Bernardo J. Clavijo ◽

...

Keyword(s):

Triticum Aestivum ◽

Bread Wheat ◽

Aegilops Tauschii ◽

Weighted Average ◽

Wheat Genome ◽

D Genome ◽

Genetic Studies ◽

Final Assembly ◽

Bread Wheat Genome ◽

Diploid Ancestor

AbstractCommon bread wheat, Triticum aestivum, has one of the most complex genomes known to science, with 6 copies of each chromosome, enormous numbers of near-identical sequences scattered throughout, and an overall size of more than 15 billion bases. Multiple past attempts to assemble the genome have failed. Here we report the first successful assembly of T. aestivum, using deep sequencing coverage from a combination of short Illumina reads and very long Pacific Biosciences reads. The final assembly contains 15,344,693,583 bases and has a weighted average (N50) contig size of of 232,659 bases. This represents by far the most complete and contiguous assembly of the wheat genome to date, providing a strong foundation for future genetic studies of this important food crop. We also report how we used the recently published genome of Aegilops tauschii, the diploid ancestor of the wheat D genome, to identify 4,179,762,575 bp of T. aestivum that correspond to its D genome components.

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Suppression of rust resistance in bread wheat (Triticum aestivum L.) by D-genome chromosomes

Genome ◽

10.1139/g92-043 ◽

1992 ◽

Vol 35 (2) ◽

pp. 276-282 ◽

Cited By ~ 54

Author(s):

D. Bai ◽

D. R. Knott

Keyword(s):

Triticum Aestivum ◽

Leaf Rust ◽

Bread Wheat ◽

Stem Rust ◽

Chinese Spring ◽

Rust Resistance ◽

Leaf Rust Resistance ◽

Triticum Aestivum L ◽

D Genome ◽

Or Genes

Several tests were done in bread wheat (Triticum aestivum L.) to demonstrate the occurrence of genes on D-genome chromosomes that suppress resistance to leaf rust (Puccinia recondita f. sp. tritici Rob. ex Desm.) and stem rust (Puccinia graminis f. sp. tritici Eriks. &Henn.). Ten rust-resistant wild tetraploid wheats (T. turgidum var. dicoccoides) were crossed with both durum (T. turgidum var. durum) and bread wheats. In all cases, resistance to leaf rust and stem rust was expressed in the hybrids with durum wheats but suppressed in the hybrids with bread wheats. Crosses were made between five diverse durum wheats and four diverse bread wheats. The pentaploid hybrid seedlings of 12 crosses were tested with leaf rust race 15 and in all cases the resistance of the durum parents was suppressed. Fourteen D-genome disomic chromosome substitution lines in the durum wheat 'Langdon' were tested with stem rust race 15B-1 and leaf rust race 15. Chromosomes 1B, 2B, and 7B were found to carry genes for resistance to stem rust but no suppressors were detected. Chromosomes 2B and 4B carried genes for resistance to leaf rust, and 1D and 3D carried suppressors. Crosses between seven D-genome monosomies of 'Chinese Spring' and three dicoccoides accessions showed that 'Chinese Spring' possesses genes on 1D, 2D, and 4D, which suppress the stem rust resistance of all three dicoccoides accessions. All three chromosomes must be present to suppress resistance, indicating that some form of complementary gene interaction is involved. In addition, 'Chinese Spring' carries a gene or genes on 3D that suppresses the leaf rust resistance of all three dicoccoides accessions, plus a gene or genes on 1D that suppresses the leaf rust resistance of only one of them. The data raise some interesting questions about the specificity of the suppressors. The high frequency of occurrence of suppressors in the bread wheat population suggests that they must have a selective advantage.Key words: Triticum aestivum, stem rust, leaf rust, rust resistance, suppressor.

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Correlation and Path Coefficient Studies of Yield and Yield Associated Traits in Bread Wheat (Triticum aestivum L.) Genotypes

Advances in Plants & Agriculture Research ◽

10.15406/apar.2017.06.00226 ◽

2017 ◽

Vol 6 (5) ◽

Cited By ~ 1

Author(s):

Ermias Assefa

Keyword(s):

Triticum Aestivum ◽

Bread Wheat ◽

Triticum Aestivum L ◽

Path Coefficient

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Response of Yield and Grain Quality of some Bread Wheat (Triticum aestivum L.) Genotypes to Different Sowing Dates

Journal of Plant Production ◽

10.21608/jpp.2016.46876 ◽

2016 ◽

Vol 7 (10) ◽

pp. 1043-1051

Author(s):

Magda Abd El-Rahman ◽

Aml El-Saidy

Keyword(s):

Triticum Aestivum ◽

Bread Wheat ◽

Grain Quality ◽

Triticum Aestivum L ◽

Sowing Dates

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A Microsatellite Map of Wheat

Genetics ◽

10.1093/genetics/149.4.2007 ◽

1998 ◽

Vol 149 (4) ◽

pp. 2007-2023 ◽

Cited By ~ 8

Author(s):

Marion S Röder ◽

Victor Korzun ◽

Katja Wendehake ◽

Jens Plaschke ◽

Marie-Hélène Tixier ◽

...

Keyword(s):

Bread Wheat ◽

Reference Population ◽

Triticum Aestivum L ◽

Wheat Genome ◽

D Genome ◽

B Genome ◽

Microsatellite Map ◽

A Genome ◽

Polymorphic Microsatellite ◽

Primer Sets

Abstract Hexaploid bread wheat (Triticum aestivum L. em. Thell) is one of the world's most important crop plants and displays a very low level of intraspecific polymorphism. We report the development of highly polymorphic microsatellite markers using procedures optimized for the large wheat genome. The isolation of microsatellite-containing clones from hypomethylated regions of the wheat genome increased the proportion of useful markers almost twofold. The majority (80%) of primer sets developed are genome-specific and detect only a single locus in one of the three genomes of bread wheat (A, B, or D). Only 20% of the markers detect more than one locus. A total of 279 loci amplified by 230 primer sets were placed onto a genetic framework map composed of RFLPs previously mapped in the reference population of the International Triticeae Mapping Initiative (ITMI) Opata 85 × W7984. Sixty-five microsatellites were mapped at a LOD >2.5, and 214 microsatellites were assigned to the most likely intervals. Ninety-three loci were mapped to the A genome, 115 to the B genome, and 71 to the D genome. The markers are randomly distributed along the linkage map, with clustering in several centromeric regions.

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