Nitrate and ammonium effect on indian mustard seedling grown under salinity stress

Seed germination and seedling growth of two Brassica juncea L. cultivars viz, Kranti and T-59 were studied under two salinity levels (20 and 200 mM NaCl) in the presence of nitrate or ammonium included in 1/2 strength Hoagland medium. Higher salinity level, 200 mM NaCl reduced seed germination and seedling growth. Decreased seedling growth under high salinity was due to reduction in root/shoot elongation and dry mass accumulation. However, low salinity level, 20mM NaCl increased the seedling length and bio-mass accumulation in both the cultivars over control. Supplementation of nitrate or ammonium (10mM) induced the growth further at low salinity and alleviated higher salinity caused growth inhibition to some extent. Cultivar Kranti recovered growth a little more than T-59 under higher salinity level on nitrogen supply. The nitrogen alleviation in the seedling growth under salinity was attributed to increase in seedling vigour and level of some nitrogenous metabolites in leaf and root tissues.