Rationality of using various physiological and yield related traits in determining salt tolerance in wheat
Improving the grain yield of wheat under stress conditions is always the major goal of plant scientist and breeder research. This study was conducted on five bread wheat genotypes with different salt tolerance potential using 8 and 15 dS m-1 salinity levels in pots filled with sandy clay loam soil. This study aimed to evaluate the significance of various physiological determinants commonly used for salt tolerance along with yield and yield related traits of wheat, especially grain yield. Plant relative growth rate, chlorophyll content index (CCi), water relations and biomass was recorded along with ionic (Na+ and K+) and yield related traits of wheat plant. The reduction in relative growth rate (RGR) was up to 34% in salt tolerant and 64% in salt sensitive wheat genotypes at 15 dS m-1 salinity treatment. Na+ in leaf was increased by about 3 folds of control, while K in leaves decreased with increase in salinity and reduction was 34% in salt tolerant and 52% in the salt sensitive wheat genotype as compared to control plants. It was also observed that the number of spikelets per spike together with number of tillers per plant was the most sensitive parameters for salt tolerance. We conclude that these characteristics might be selected as desirable traits for a cross breeding programs or engineering such wheat that have ability to produce more tillers and/or number of spikelets per spike under stress to get varieties with better production in saline environments.
Key words: Wheat, salinity, yield, traits, ionic, physiological.