Analysis On The Genetic Diversity Of Aegliops Tauschii And The Comparison With D Genome Of Wheat

Aegliops tauschii, the donor of D genome of Triticum aestivum, is the important genetic resource for the improvement of bread wheat with valuable gene resources, it has some desirable characters such as high tillering ability, good fecundity, high protein content and excellent resistance to powdery mildew, stripe rust and stem rust, as well as tolerance to low temperature and preharvest sprouting. Aegliops tauschii, which has a few of region-specific genotypes involved in the origin of hexaploid wheat, contains much wider genetic background than wheat. In this study, the genetic diversity of different Ae. tauschii populations and the recognition of subspecific taxa and the comparison between Aegliops tauschii and wheat were investigated by 40 pairs SSR primer. The main results were describes as follows:(1) The results of PCA and UPGMA cluster analyses revealed that Aegliops tauschii has two subspecies. The accessions having markedly moniliform spikes were assigned to Ae. tauschii Coss. subspecies strangulata (Eig) Tzvel., whereas those having cylindrical spikes to Ae. tauschii Coss. subspecies tauschii. The accessions having mildly moniliform were assigned to both Ae. tauschii Coss. subspecies strangulate and Ae. tauschii Coss. subspecies tauschii, and it was difficult to identify only by spikelet-shape.(2) The genetic diversity and differentiation of 206 Aegilops tauschii accessions from all over the world, were investigated by SSR assay with 40 pairs of primers homogeneously distributed on 7 chromosomes of Ae. tauschii. The results demonstrated that 276 allelic variations were detected, with an average allelic variations number of 6.8780 and range of variation 4～12. Polymorphism information content (PIC) and Shannon's information index (1) value were 0.8721 and 1.3977, with the variation range 0.6162～0.9272 and 0.9429～1.6746, respectively. The results indicated that Aegliops tauschii contains much wider genetic background than common wheat.(3) Genetic diversity had been compared between common wheat including one synthetic wheat and 71 wheat accessions from different origin and age and Ae. tauschii. The results indicated that the genetic diversity of Ae. tauschii was rich than common wheat. The effective number of alleles, average of PIC and I were 2.2211,0.2869 and 0.4634, respectively; whereas Ae.tauschii's effective number of alleles, average of PIC and I were 4.6123,0.8736 and 1.3839, respectively. In addition, the PIC of cfd168, cfd188, cfd266, gdm141, gwm182, cfd39, cfd63, gdm129, gdm292 and cfd10 were 0. The genetic distance between synthetic wheat and wheat is far, and it could be used to improve the wheat or develop mapping population.