Abstract:
The effect of growth regulators like Ascophyllum nodosum extract (0.1%), Triacontanol (5 ppm) and 28-Homobrassinolide (1ppm) in
ameliorating salt stress in two genotypes of rice (IR-29 and CSR-4) under three salinity levels viz. S0
=Non saline as control, S1
=40 mmol
l
-1 NaCl+20 mmol l-1 Na2
SO4
+20 mmol l-1 CaCl2
(ECe 9.6 dSm-1) and S2
=60 mmol l-1 NaCl+30 mmol l-1 Na2
SO4
+30 mmol l-1 CaCl2 (ECe 13.5
dSm-1) was studied on germination, seedling growth, physiological and biochemical parameters. The presowing treatment of Ascophyllum
nodosum 0.1% extract and 28-Homobrassinolide 1 ppm were found to be beneficial in inducing salt tolerance in both sensitive (IR-29)
and tolerant genotype (CSR-4). These growth regulators significantly increased the germination, seedling vigour and membrane stability
index in rice seedlings under saline condition as compared to control (water soaked). Boththegrowth regulators significantly increased the
activity ofantioxidant enzymeslike super oxide dismutase, glutathione reductase, catalase and peroxidase under salt stress condition as
compared to that of Triacontanol 5 ppm and water soaked seeds.
