Evaluation and selection of international barley lines under late season drought stress conditions

Development of new cultivars which produce an acceptable grain yield with minimum irrigation in spring and provide high sustainable yield in different environments is of great importance in expansion of breeding programs. Field experiments were conducted with 171 International barley genotypes that had been received from ICARDA (SPII07 Nursery) including CVs Reyhan03 as a check using systematic design under both normal irrigation and late season limited water conditions at Karadj and Mashhad agricultural research stations in 2005-06cropping season. Tolerance and susceptibility of the genotypes to drought stress were calculated using STI, SSI, TOL, MP and GMP indices. Based on results in Mashhad and Karadj stations and considering the grain yield under both normal and stressed conditions as well as drought tolerance and susceptibility indices, genotypes no 159, 160, 162, 116, 104 and 106 were determined as the most tolerant genotypes and genotypes no 131, 64, 24, 26, 130, 63, 30 and 118 as the most susceptible genotypes. Pearson correlation coefficients were used to determine the relationships between the grain yield and studied indices. These coefficients showed that MP, GMP and STI indices had a positive significant correlation with grain yield under both normal and stressed conditions which indicates these indices can be considered as the most appropriate indices for the selection of tolerant genotypes.