Study of Genetic Variability, Heritability and Relationship between Grain Yield and Yield-Related Traits on Bread Wheat Genotypes under Dry Land Conditions

In order to study of variability, relationship among traits, direct and indirect effects of traits influencing grain yield, 18 lines and cultivars of bread wheat were evaluated in a randomized complete block design with four replications during 2009-2012 cropping seasons. Coefficients of genotypic and phenotypic variability showed that lines had high genetic variation for peduncle length, grain yield and number of spikes per square meter. High genetic variability revealed that these traits could be improved via selection. Heritability was relatively low for grain yield, biological yield and number of grains in spike and was high for peduncle length, days to maturity, plant height, spike weight and spike length. High heritability coupled with high genetic gain obtained for peduncle length, spike length, number of spikes per square meter and spike weight showed that selection for these traits could be effective. Results of path analysis showed that spike weight, number of grains in spike, biological yield and peduncle length had positive direct effect on grain yield. Also, indirect effects of number of spike per square meter via spike weight on grain yield could be considered for genotypes selection with high yield.