Evaluation of Aegilops tauschii Coss. germplasm for agro- morphological traits and genetic diversity using SSR loci

A set of 85 Aegilops tauschii accessions were evaluated for morphological traits, disease resistance, high molecular weight glutenin subunits and genetic diversity using D genome specific SSR markers. Screening for leaf rust, stripe rust and Karnal bunt (KB) resistance over four years identified Ae. tauschii ssp strangulata as a potential source for new leaf rust and stripe rust resistance genes and Ae. tauschii ssp tauschii as a source for KB resistance. The Ae. tauschii germplasm also showed a lot of variability for high molecular weight glutenin profile showing 16 combinations of slow (1Dx) and fast (1Dy) mobility subunits. A total of 51 D-genome specific simple sequence repeat (SSR) markers amplified a total of 241 alleles in 85 accessions of Ae. tauschii and two bread wheat cultivars. The number of alleles per locus varied from 2 to 11 with an average of 4.75. Polymorphism Information Content (PIC) values for all the 51 primer pairs ranged from 0.02 to 0.88 with an average of 0.62. A phylogenetic tree generated, based on Dice dissimilarity matrix and cluster analysis, led to the clustering of the Ae tauschii accessions into two major groups. The cluster I comprised primarily the strangulata accessions whereas the cluster II comprised of accessions belonging to both the subspecies indicating some gene flow from ssp strangulata to tauschii. Genetically diverse Ae. tauschii accessions with disease resistance and better agronomic and quality traits are being used for the introgression of desirable traits to bread wheat for commercial exploitation.