Salinity Induced Responses to NRA and Nodulation in Kidney Bean (PHASEOLUS VULGARIS Linn.)

A field experiment was conducted with two varieties of kidney bean viz. Pant bean-2 and PDR-14 to study the effect of salinity on nitrate reductase and root nodulation. Salinity is detrimental to growth of leguminous plants as it affects nodulation and NRA. In a salt tolerant variety of kidney bean viz. , Pant bean-2 the minimum NRA was noticed, while in highly tolerant var. PDR-14 higher NRA was observed with the increasing salt concentration from 4 to 8 mScrn-1. The formation of root nodules, size, number, fresh weight of single nodule and haemoglobin contents were found suppressed significantly in both the varieties of kidney bean indicating thereby that with an increasing salt concentrations kidney bean plant might tend to overcome the adverse effect of salinity on nodulation by increasing NR activity in highly salt tolerant variety PDR-14 in comparision of var. Pant bean-1. It may be inferred that reduced NRA might be due to the specific effects of Cl, Na+ and Ca++ ions on uptake and transport of NO3- ions.