SOME PHYSIOLOGICAL AND GENETIC DETERMINANTS OF SALT TOLERANCE IN SORGHUM (SORGHUM BICOLOR (L.) MOENCH): BIOMASS PRODUCTION AND NITROGEN METABOLISM

Soil salinization is the most important limiting factor in plant productivity all over the world. To fulfill the food, feed, fodder and industrial raw material demands of growing population, development of salt tolerant and high yielding crop genotypes are necessary. The genotypes having efficient N metabolism produce high biomass/plant productivity under saline conditions are tolerant one. This study was conducted to explore the salinity induced changes in nitrogen metabolism of sorghum. A sand culture experiment with four sorghum genotypes was conducted in NIAB wire-house under natural conditions in plastic pots containing 0, 10 dS m(-1) NaCl salinity solutions along with 1/5 Hoaglands nutrient solution. Physiological parameters like dry biomasss of shoots and roots, leaf proteins, total nitrogen, total free amino acids, nitrate reductase activity, and NO3 were reduced due to salinity in all sorghum genotypes. Salinity influence was more pronounced in Noor medium sensitive and FJ-115 sensitive. On the basis of results obtained for nitrogen metabolism, sorghum lines JS-2002 and Sandalbar can be categorized as tolerant, Noor medium sensitive and FJ-115 as sensitive one.