Assessment of Diversity and Identifying of Effective Traits on Grain Yield of bread wheat Promised Lines under Salt Stress Conditions

In the major wheat growing countries, wheat growth and yield are negatively affected by salinity and breed tolerant cultivars through selection and breeding techniques is necessary to solve this problem. Relationship among yield, and its related traits in 23 wheat cultivars and promised lines were studied under salt stress conditions using a randomized complete block design with three replications at research field of Birjand University. Bread wheat cultivars and promised lines cultivated at two cropping seasons of 2010 and 2011 and irrigated with 10.81 ds.m-1 irrigation water during each season. Investigated cultivars and lines were significantly different in almost all traits except for days to heading and peduncle length. Correlation analysis showed that grain yield was significantly related to all traits except for number of spike per square meter and grain weight per spike. Regression analysis using step-wise method revealed that 81 percent of total variation exists in grain yield have been determined by grain filling period, plant height, and spike and peduncle length, in which grain filling period alone determined 54% of the variations. According to path analysis, grain filling period had the highest direct effect and peduncle length had the highest indirect effect via plant height on grain yield. These four traits are suggesting as suitable traits for selection of high-yield wheat lines under salt stress conditions.