Selection of agro-morphological traits related to spring wheat yield in dryland conditions as selection indices

This research was carried out to investigate the relationship between agronomic traits and yield using 132 spring wheat genotypes. Genotypes were cultivated in alpha-lattice design with two replications at the research farm of Gonbad Kavous agricultural research station. The highest correlation was observed respectively between yield with seed filling rate (0.84), harvest index (0.84), biomass (0.86), 1000 grain weight (0.58), grain weight per spike (0.44), and weight of the spike (0.41). Yield had a negative and significant correlation with days to maturity (-0.57) and days to heading (-0.45). Seed filling rate and days to heading were introduced into the model as important traits affecting grain yield and 78.1% of yield variation was justified. Grain filling rate and days to heading had direct effects of 0.73 and -0.285 respectively. The traits of seed filling rate and days to heading can be used as selection indices in dryland conditions. The results of cluster analysis showed that genotypes 38, 39 and 52 were in 7 group. This group was superior to other groups in terms of average traits. Genotypes in groups 5 and 7 can be used to aggregate performance-related traits.