Effect of abscisic acid and benzyladenine on growth and ion accumulation of wheat under salinity stress

A glass-house pot experiment was conducted to assess the role of Abscisic acid (ABA) and Benzyladenine (BA) on growth and ion accumulation of two spring wheat cultivars viz., cv. Inqulab-91 and cv. SAARC-1 under salinity stress. Seeds of both cultivars were treated prior to sowing with ABA and BA each at 10(-5) M for 24h. Three weeks old plants of both the cultivars were exposed to 0 and 100 mol m(-3) NaCl. Plants were harvested three weeks after salt treatment. Fresh and dry weight of shoot and root decreased with salt treatment, whereas ABA and BA treatments caused a significant ameliorative effect on both the cultivars. Under salt stress, plant height was more adversely affected in Inqulab-91 than in SAARC-1. Salt treatment increased the concentration of Na+ and Cl- in flag leaf of both the cultivars. Both ABA and BA treated plants showed significant decrease in Na+ content but increased K+ content in flag leaf of both the cultivars. ABA and BA treatment decreased plant height but increased number of grains per spike and grain yield. ABA and BA treatments further augmented the stimulatory effect of salt on proline accumulation. Higher proline accumulation was observed in SAARC-1 than in Inqulab-91 with ABA and BA treatment. Under salt stress the hormone mediated osmoregulation by increased proline production and the selectivity in uptake and accumulation of toxic ions like Na+ and CY has been discussed. BA was more effective to increase chlorophyll "a" & "b, flag leaf area, number of grains per spike and grain yield, under salt stress as well as in non saline soil than ABA.