IN SITU ASSESSMENT OF MORPHO-PHYSIOLOGICAL RESPONSE OF WHEAT (TRITICUM AESTIVUM L.) GENOTYPES TO DROUGHT

In situ studies were conducted to assess the morpho-physiological responses of wheat genotypes to PEG-induced water stress. Wheat genotypes were raised in hydroponic cultures where plants were nourished with 1/2 strength Hoagland solution. Plants were exposed to 00, 10, 20, 30 and 40% PEG-6000 at 4-leaf stage. PEG was applied in split doses @ 10% with an interval of 15 days. Significant differences (p <= 0.05) were recorded for all the parameters studied due to genotypes and PEG concentrations. Wheat genotypes showed negative but variable response to PEG concentrations for shoot length, root length, root/shoot ratio and root mass whereas PEG imposed stress had positive impact on proline content and abscisic acid (ABA). Genotype Khattakwal attained maximum shoot length in PEG induced stress. Maximum root/shoot ratio and root mass was recorded in Ghaznavi-98 while Tatara and Khattakwal attained maximum relative water content. Endogenous proline and ABA content increased up to 10 fold in response to 40% PEG. Maximum proline was accumulated by Khattakwal whereas maximum ABA by ICP-3.