Field Screening of Salinity Tolerance in Iranian Bread Wheat Lines

Soil and water salinity are major constraints for wheat production in Iran. High genetic diversity for salinity tolerance has been observed in Iranian bread wheat (Triticum aestivum L.) genotypes. Hence, these genotypes can be evaluated under field and controlled conditions for identifying new genotypes with better performance under salt stress conditions. In a 2-yr study, we evaluated 97 promising Iranian lines with different levels of salinity tolerance along with three tolerant cultivars as checks under field conditions in Yazd province of Iran. Plant materials were grown under saline and normal field conditions (electrical conductivity [EC] of 10.0 and 3.0 dS m^-1, respectively). Significant genetic variation (P < 0.01) in salinity tolerance was observed among wheat genotypes. In this study, an equation was developed for estimating a stress tolerance score (STS). The results of the equation were identical to those of multivariate analyses. The STS equation is much easier to use than complicated multivariate analyses. Therefore, it is suggested as a screening tool for identification of salt-tolerant wheat genotypes. Ultimately, ten lines with higher tolerance to salt stress, in comparison with tolerant checks, were detected. These lines can be used in wheat breeding programs for salt-affected areas.