Genetic dissectionof grain yield and some morphological traits in Iranian bread wheat under field normal and salt stress conditions using Jinks-Hayman approach

Salinity stress is one of the serious threats for high productivity of crops, especially in wheat as a key staple food for world population. Understandingthe inheritance of yield and yield components is very important in wheat breeding programs for salinity tolerance. In this research, to evaluatethe gene action of yield and yield components, seven Iranian wheat cultivars including Falat, Bam, Ghods, Roshan, Arg, Kavir and Pishtaz along with their crosses were cultivated in randomized complete block design with three replications under both normal and salinity stress conditions at National Salinity Research Center,Yazd province, Iran,in 2014. All initial assumptions for the traits were indefeasible, therefore combined analysis of variance was done based on Jinks-Hayman approach. The results of analysis of variance showed that all traits including grain yield, biological yield, tiller number, peduncle length, plant height and 100 grain weight had significantly simple additive effect “a” and “a × environment”interaction effect. Also, the simple effect of b3 which is equal to specific combining ability in method 1 diallel analysis, and its interaction with environment were significant for all studied traits. Significant “a” and “b3” terms indicated the important role of additive and dominance effects in the inheritance of trait in both conditions. In this research, the cultivar Roshan had the best combining ability for yield, biomass and tiller number. Generally, the gene type for controlling traits, gene action, potential of dominance and recessive genes in parents,maternal effects and additive and dominance effects were different under twoenvironmental conditions, non-stress and salinity stress. Estimated high broad sense and moderate to high narrow sense heritabilities indicated that thestudied genetic materials could be promisingly used to improve these traits under non-stressconditions aa well as salinitytolerance.Therefore, it ispossibleto select tolerant genotypes to salinity stress in Iranian bread wheat cultivars used in this research.