PHYSIOLOGICAL RESPONSES OF VARIOUS WHEAT GENOTYPES TO SALINITY

Effect of NaCl stress on yield and various physiological parameters (leaf area, osmotic potential, glycine-betaine, total sugars and chlorophyll contents) was studied in 7 wheat genotypes (Lu-26s, Sarsabz, Bhittai, KTDH22, Khirman, B-7012 and Bakhtawar) grown under two salinity levels (NaCl 1.5 and 12 dS/m) in the cemented tanks having river sand. Seeds were allowed to germinate under normal condition and salinity treatments were imposed after one week of germination. Salinity was imposed by irrigating the crop at an interval of two weeks or whenever required with 1/4(th) Hoagland nutrient solution having respective NaCl concentrations. Salinity reduced the grain yield, leaf area and chlorophyll contents however it resulted in an increase in the osmotic potential, glycine-betaine and total sugar contents. The results clearly indicated that under salt stress, genotypes with higher leaf area, osmotic potential, glycine-betaine, total sugar and chlorophyll contents, had more grain yields as compared to the genotypes with lower values for these attributes. On the basis of yield reduction, four genotypes viz., Lu-26s, Sarsabz, Bhittai and KTDH-22 were found to be salt tolerant whereas genotypes V-7012, Khirman and Bakhtawar were designated as sensitive ones. The tolerant genotypes also maintained higher leaf area, osmotic potential, glycine-betaine, total sugar and chlorophyll contents under saline conditions.