Genetic diversity and trait association research in emmer wheat (Triticum dicoccum L.) germplasm lines for moisture stress

Seventy emmer wheat (Triticum dicoccum L.) germplasm lines were used to determine genetic diversity and their response for drought responsive traits, which were sown in augmented design under non stress and moisture stress condition (at 65 days after sowing i.e., grain filling phase). Morpho-physiological traits associated with tolerance to drought at the reproductive stage of plant growth were recorded. The results of the analysis of variance exhibited significant variation between germplasm lines in all studied traits. In comparison to the non-stress condition, the root length and root volume was increased under moisture stress condition. Conversely the grain yield related traits showed a significant decline under moisture stress. A total of 15 trait specific simple sequence repeats (SSR) markers were used to determine polymorphism across germplasms for different drought associated traits. The marker xgwm149 (1.53) exhibited the highest Shannon Index (I) gene diversity, while polymorphic information content (PIC) index values ranged from 0.16 to 0.50 depicting wide genetic diversity. According to PIC, eleven markers were informative during this study. Simple regression analysis showed that xgwm493 marker had the most significant relationship with root and shoot length, (at 0.01 significant levels). The xgwm165 and xgwm493 markers showed a significant correlation with grain yield under non stress and stress conditions respectively. Single marker analysis trait association revealed, 12 of the 15 SSR markers had significant association with moisture stress responsive traits. These markers could be used for marker-assisted selection to improve drought stress tolerance in emmer wheat.