Uncovering the Iranian wheat landraces for salinity stress tolerance at early stages of plant growth

Soil salinity is a major global environmental factor limiting plant growth and productivity. Wheat seeds need to be able to germinate and establish seedlings in saline soils for sustained productivity. In this study, we investigated seed germination-related traits under salt stress conditions in 239 diverse Iranian wheat landraces for evaluation of salt stress tolerance. Seed of the landraces along with relevant checks was germinated in salt and control solutions until 14 days. Initially, 10 randomly selected accessions were subjected to six different (25 mM, 50 mM, 75 mM, 100 mM, 125 mM, 150 mM) salinity levels for standardization. The salinity level 125 mM NaCl was found more effective concentration for the discrimination of genotypes for various physiological indices, viz. germination percentage, coleoptile length, root and shoot length, fresh root and shoot weight, dry root and shoot weight, and vigor index. After 14 days, germination percentage and all seedling traits were found to be affected due to salinity. Salt tolerance index maintained a significant positive correlation with seedling traits which indicates that these parameters could be used as selection criteria for screening wheat genotypes against salt stress. Significant differences were observed for coleoptile length, root–shoot length, fresh root–a shoot weight, dry shoot weight, and vigor index among the wheat landraces. From the overall observation of germination percentage and early seedling growth, it was concluded that the wheat landraces accessions including IWA 8600278, IWA 8600291, IWA 8611786, IWA 8600179, IWA 8600303, and IWA 8610487 showed better salt tolerance than Kharchia 65, the universal salt-tolerant variety used so far in wheat-breeding programs.