ANALYSIS OF SALINITY TOLERANCE POTENTIAL IN SYNTHETIC HEXAPLOID WHEAT

Salinity is an important environmental constraint for agricultural crops including wheat. This experiment was performed to examine salinity tolerance in synthetic hexaploid wheats as compared to three commercial wheat varieties (Zarghoon-79, Kharchia and Shorawaki). All genotypes were grown at various salinity levels (0 mM, 50 mM, 100 mM, 150 mM and 200 mM) and then screened based on seed germination rate, length of root and shoot and fresh and dry weight of root and shoot. Biochemical parameters including photosynthetic pigments (chlorophyll a, chlorophyll b, carotenoids), ionic content (Na+, K+, Ca+), antioxidant enzymes; superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), total soluble protein (TSP) and total soluble sugar (TSS) were also conducted on these genotypes. The result of analysis of variance showed that for most traits, there were highly significant differences among salt concentrations, varieties and their interaction. The synthetic lines (genotypes 1 to 10) showed significant tolerance to different levels of salt (Sodium Chloride; NaCl) as compared to commercial wheat cultivars (Zarghoon-79, Kharchia and Shorawaki). Two synthetic lines; genotypes 2 and 4 performed the best under stress condition. It has also been observed that wheat seedlings performed better at 50 mM concentration of NaCl as compared to control (0 mM NaCl) and other levels of salt (100 mM, 150 mM, 200 mM). Correlation analysis revealed that the increase of germination percentage, shoot and root length, fresh weight, dry weight, chlorophyll a, chlorophyll b, carotenoids and potassium were significantly correlated with the decrease in germination rate, sodium, calcium, SOD, POD, CAT, TSP and TSS.