Analysis of relationships between Aegilops tauschii and the D genome of wheat utilizing microsatellites

Genome ◽  
2000 ◽  
Vol 43 (4) ◽  
pp. 661-668 ◽  
Author(s):  
Tamás Lelley ◽  
Maria Stachel ◽  
Heinrich Grausgruber ◽  
Johann Vollmann
Keyword(s):  
Genetic Diversity ◽  
Triticum Aestivum ◽  
Hexaploid Wheat ◽  
Aegilops Tauschii ◽  
Null Alleles ◽  
The Caspian Sea ◽  
D Genome ◽  
Wheat Varieties ◽  
Center Of Origin ◽  
Primer Sets

Sixty Aegilops tauschii accessions and 60 European hexaploid wheat varieties were analyzed with 14 wheat microsatellite (WMS) primer sets to (i) study the phylogeny of Ae. tauschii, (ii) search for a specific genotype of Ae. tauschii most closely related to the D genome of hexaploid wheat, and (iii) narrow down the presumed birthplace of the latter. An average of 6.5 and 4.0 alleles per locus was detected in Ae. tauschii and in wheat, respectively. The highest genetic diversity of Ae. tauschii was found in Transcaucasia and southeast of the Caspian Sea. Distribution of the 87 alleles (without null alleles) found in Aegilops did not allow differentiation of the species into the two subspecies strangulata and tauschii. Excluding null alleles, 41 alleles occurred parallel in wheat and in Aegilops. Data obtained in this study supports the view of the D genome of hexaploid wheat being a composite of several sources but does not support subsp. strangulata as the possible major source of the D genome. The highest number of region-specific alleles (three) in Ae. tauschii occurring also in the D genome of wheat, and therefore most indicative for its evolution was found in present-day Georgia, where subsp. strangulata is not endemic.Key words: Triticum aestivum, Aegilops tauschii, genetic distance, center of origin, evolution.

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

Genome ◽  
2009 ◽  
Vol 52 (6) ◽  
pp. 576-587 ◽  
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.

scholarly journals Empirical verification of heterogeneous DNA fragments generated from wheat genome-specific SSR primers

2008 ◽  
Vol 88 (6) ◽  
pp. 1065-1071 ◽  
Author(s):  
Qijiao Chen ◽  
Lianquan Zhang ◽  
Zhongwei Yuan ◽  
Zehong Yan ◽  
Youliang Zheng ◽  
...  
Keyword(s):  
Common Wheat ◽  
Hexaploid Wheat ◽  
Chinese Spring ◽  
Triticum Turgidum ◽  
Sequence Data ◽  
Aegilops Tauschii ◽  
Single Locus ◽  
Synthetic Hexaploid Wheat ◽  
D Genome ◽  
Synthetic Hexaploid

Due to the high polymorphisms between synthetic hexaploid wheat (SHW) and common wheat, SHW has been widely used in genetic studies. The transferability of simple sequence repeats (SSR) among common wheat and its donor species, Triticum turgidum and Aegilops tauschii, and their SHW suggested the possibility that some SSRs, specific for a single locus in common wheat, might appear in two or more loci in SHWs. This is an important genetic issue when using synthetic hexaploid wheat population and SSR for mapping. However, it is largely ignored and never empirically well verified. The present study addressed this issue by using the well-studied SSR marker Xgwm261 as an example. The Xgwm261 produced a 192 bp fragment specific to chromosome 2D in common wheat Chinese Spring, but generated a 176 bp fragment in the D genome of Ae. tauschii AS60. Chromosomal location and DNA sequence data revealed that the176 bp fragment also donated by 2B chromosome of durum wheat Langdon. These results indicated that although a single 176 bp fragment was appeared in synthetic hexaploid wheat Syn-SAU-5 between Langdon and AS60, the fragment contained two different loci, one from chromosome 2D of AS60 and the other from 2B of Langdon which were confirmed by the segregating analysis of SSR Xgwm261 in 185 plants from a F2 population between Syn-SAU-5 and Chinese Spring. If Xgwm261 in Syn-SAU-5 was considered as a single locus in genetic analysis, distorted segregation or incorrect conclusions would be yielded. A proposed strategy to avoid this problem is to include SHW’s parental T. turgidum and Ae. tauschii in SSR analysis as control for polymorphism detection. Key words: Synthetic hexaploid wheat, microsatellite, segregation distortion, Xgwm261, transferability

Comparative assessment of SCoT and ISSR markers for analysis of genetic diversity and population structure in some Aegilops tauschii Coss. accessions

2021 ◽  
pp. 1-9
Author(s):  
Atefeh Nouri ◽  
Maryam Golabadi ◽  
Alireza Etminan ◽  
Abdolmajid Rezaei ◽  
Ali Ashraf Mehrabi
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Aegilops Tauschii ◽  
Inter Simple Sequence Repeat ◽  
Issr Markers ◽  
Start Codon ◽  
D Genome ◽  
Breeding Programmes ◽  
High Level ◽  
Effective Multiplex Ratio

Abstract Aegilops tauschii, the diploid progenitor of the wheat D-genome, is a valuable genetic resource for wheat breeders. In this study, we compared the efficiency of inter-simple sequence repeat (ISSR) (as an arbitrary technique) and start codon targeted (SCoT) (as a gene-targeting technique) markers in determining the genetic diversity and population structure of 90 accessions of Ae. tauschii. SCoT markers indicated the highest values for polymorphism information content, marker index and effective multiplex ratio compared to ISSR markers. The total genetic diversity (Ht) and genetic diversity within populations (Hs) parameters were comparably modest for the two marker systems. The results of the analysis of molecular variance showed that the genetic variation within populations was significantly higher than among them (ISSR: 92 versus 8%; SCoT: 88 versus 12%). Furthermore, SCoT markers discovered a high level of genetic differentiation among populations than ISSRs (0.19 versus 0.05), while the amount of gene flow detected by ISSR was higher than SCoT (2.13 versus 8.62). Cluster analysis and population structure of SCoT and ISSR data divided all investigated accessions into two and four main clusters, respectively. Our results revealed that SCoT and ISSR fingerprinting could be used to further molecular analysis in Ae. tauschii and other wild species. The high-genetic variability found in this study also indicates the valuable genetic potential present in the investigated Ae. tauschii germplasm, which could be utilized for future genetic analysis and linkage mapping in breeding programmes.

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

Genome ◽  
2005 ◽  
Vol 48 (6) ◽  
pp. 1120-1126 ◽  
Author(s):  
Didier Lamoureux ◽  
Daniel G Peterson ◽  
Wanlong Li ◽  
John P Fellers ◽  
Bikram S Gill
Keyword(s):  
Triticum Aestivum ◽  
Bread Wheat ◽  
Aegilops Tauschii ◽  
Triticum Aestivum L ◽  
D Genome ◽  
Genomic Libraries ◽  
Gene Space ◽  
Fold Enrichment ◽  
Gene Enrichment ◽  
Fold Reduction

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.

Genetic diversity and gene-pool subdivisions of diploid D-genome Aegilops tauschii Coss. (Poaceae) in Iran as revealed by AFLP

2008 ◽  
Vol 55 (8) ◽  
pp. 1231-1238 ◽  
Author(s):  
Hojjatollah Saeidi ◽  
Badradin Ebrahim Sayed Tabatabaei ◽  
Mehdi Rahimmalek ◽  
Majid Talebi-Badaf ◽  
Mohammad Reza Rahiminejad
Keyword(s):  
Genetic Diversity ◽  
Gene Pool ◽  
Aegilops Tauschii ◽  
D Genome
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