Investigation of the Genetic Diversity of Iranian Bread Wheat Germplasm for Tolerance to Saline Stress

Salinity stress is one of the major abiotic stresses in arid and semi-arid regions of the world, such as Iran. High genetic diversity for salinity tolerance has been observed in Iranian bread wheat genotypes. In order to analyze genetic diversity and determine the most effective characteristics on salinity tolerance, 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 stress and non-stress conditions was 10 and 2 ds.m-1, respectively. The results showed that there was a significant genetic variation between studied genotypes. According to cluster analysis based on agronomical and morphological traits, genotypes were divided into 4 categories in both non-stress and stress conditions. According to the results of the means comparison of the groups in non-stress and saline stress conditions, the genotypes No. 2, 5, 7, 8, 9, 10, 11, 12, 13, 31, 35, 38, 73, 81, 97 and 98 were identified as the most salinity-tolerant genotypes. These genotypes can be utilized for salt-affected areas and also as donor parents in wheat breeding programs for further improvement of germplasm for salinity tolerance. Also, the results of factor analysis in saline stress condition indicated a positive relationship between biological yield, harvest index and chlorophyll content with seed yield. Generally, it can be concluded that chlorophyll content trait due to the low cost and easy and non-destructive measurement than other traits could be used as a suitable criterion in selecting for increased seed yield in saline stress conditions in field.