Screening of drought tolerant cultivars in spring barley

In order to evaluation of genetic diversity of spring barley genotypes, screening drought resistance indices and identification of drought resistance varieties, 16 variaties of spring barley were evaluated in a randomised complete block design with three replications under two conditions including normal irrigated and drought stress on flowering stage in West Azerbaijan Agricultural and Natural Research Centre. Based on the potential (Yp) and stress (Ys) yield, quantitative drought resistance criteria such as: mean productivity (MP), tolerance index (TOL), geometric mean productivity (GMP), harmonic mean (HM), stress susceptibility index (SSI) and stress tolerance index (STI) were calculated. Generally in both conditions, variety Kavir/Badia with average yield of 2152 kgha-1 and variety Union 300-4 with average yield of 498.6 kgha-1 had the maximum and minimum values of yield. In both normal and drought stress conditions, the highest value of MP, GMP and HM were possessed to genotype "Kavir/Badia". Correlation analysis between drought resistance indices with potential and stress yields revealed that indices including MP, GMP, HM and STI are most suitable criteria for screening barley’s genotypes. Varieties "Kavir/Badia" and "Rihane-O5" were chosen as best drought resistant regarding to these four criteria and high values of Yp and Ys. Multivariate biplot display that the varieties "Kavir/Badia" and "Rihane-O5", "Gorgan/CM67/Pro/Svo" and "Hebe" were located next to the vectors of drought resistance indices MP, GMP, HM and STI. Also, distribution of the varieties in the biplot space manifested the presence of genetic diversity among the varieties for drought stress. Cluster analysis indicated that the farthest genetic distance were exist between two drought resistant varieties including "Kavir/Badia" and "Rihane-O5" and two susceptible varieties including"Local- chek" and "West Azerbaijan landrace".