Identification of salinity tolerant genotypes and study on relationships between yield and its components in bread wheat

In arid and semi-arid regions of the world including Iran, soil salinity is one of the major abiotic stresses. One of the ways to achieve high performance in these areas is using salt tolerant varieties. Also, study on relationships between yield and its components will improve the efficiency of a breeding program with appropriate selection criteria. In this study, 110 bread wheat genotypes were evaluated in two conditions (non-stress and saline stress) at the research field of the National Salinity Research Center (NSRC). The salinity of water used in irrigation in saline and non-stress conditions was 10 and 2 dS.m-1 respectively. In this study was used of stress tolerance index (STI) as the best indicators for evaluating of tolerant to salinity stress of bread wheat genotypes. Based on stress tolerance index (STI)and seed yield in non-stress and saline stress conditions, the linesSalt18, Salt19, Salt20, Salt21, Salt22, Salt23, Salt24, Salt25, Salt26, Salt27, Salt28, Salt29, Salt30, and varieties Arg, Bam, Rushan, Sorkhtokhm, BumiYazd, Kavir, Moghan 1, Sardari, Sharyar, Shirazhad had a high yield in the non-stress and saline stress conditions and these genotypes were selected as the most tolerant genotypes to salinity.The highest grain yield under non-stress and saline stress conditions was produced by Salt29 line (178.13 gr) and Salt24 line (164.33 gr), respectively which had more grain yield than control cultivars (Arg, Bam, Rushan, Sorkhtokhm, Bumi Yazd and Karchia). Also, based on the results of sequential path analysis, kernel weight per spike and number of fertile tillers in non-stress conditions and spike weight, number of fertile tillers, days to headingand peduncle weightin saline stress conditions were selected as first order variables.Therefore, it seems that these traits could be used as a suitable criterion in wheat breeding programs for increased seed yield in both non-stress and salinity stress conditions.