Evaluation of relationship among traits in wheat genotypes under terminal water stress conditions

To identify relationship among traits in winter wheat genotypes, 18 promising lines andtwo checks varieties were evaluated as randomized complete block design with 3 replications in two locations (Miyandoab and Hamedan) during 2006-2007 under terminal water stress conditions. Results showed that biomass had the greatest phenotypic variation coefficient. Grain yield had the positive significant correlation with biomass (0.66**), 1000 grain weight (0.66**) and plant height (0.30**). Stepwise regression analysis showed that biomass, 1000 grain weight and days to maturity explained 77.2% of the grain yield variation. Path analysis showed that biomass (0.60**) and 1000 grain weight (0.36**) had positive significant direct effects on grain yield, but days to maturity had negative significant direct effect (-0.16**) on grain yield. Factor analysis based on principal components identified four factors explaining about 72.8% of total variation among traits. Results from current research showed that biomass and 1000 grain weight can be suitable selection indices for increasing grain yield of the studied wheat genotypes under terminal water stress condition.