Evaluation of Aegilops tauschii Coss. germplasm for agromorphological traits and genetic diversity using SSR loci

Abstract

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.