Investigation of Tolerance, Yield and Yield Components of Wheat Cultivars to Salinity of Irrigation Water at Sensitive Stages of Growth

This research in order to study of tolerance ability of wheat cultivates yield and yield components to salinity of irrigation water at sensitive stages of growth، was carried out as a factorial based on a randomized complete block design with 3 replications at greenhouse of Agricultural Faculty of Bu-Ali Sina University، in 2009. Treatments were included wheat cultivars of Alvand، Tous، Sayson and Navid and salinity of irrigation water induced by sodium chloride at five levels of 0، 4، 8، 12 and 16 dS m-1. The results showed that percentage and rate of emergence، plant height، 1000-grain weight، number of seed per spike، number of spike per pot، biological and grain yield reduced by increasing salinity level. At all stress levels Navid cv. had highest emergence percentage. In non-stress and 4 dS m-1، Alvand cv. and at higher levels of stress، Tous cv. had high height in reproductive phase. At control and 4 dS m-1، Sayson cv. and at 8، 12 and 16 dS m-1، Tous cv. in majority of yield and yield components traits had significant superior than other cultivars. Tolerance index of Sayson cv. at 4 and 8 dS m-1 was more than other cultivars but at 12 and 16 dS m-1، maximum value of this index was belonged to Tous cv. At all salinity levels، Alvand cv. had least tolerance index to stress. Number of spike per pot had maximum direct effect on grain yield of wheat cultivars in stress condition. Also indirect effect of biological yield via number of spike per pot than other its indirect effects، had maximum share in wheat seed yield.