MORPHO-PHYSIOLOGICAL ASSESSMENT OF WHEAT (TRITICUM AESTIVUM L.) GENOTYPES FOR DROUGHT STRESS TOLERANCE AT SEEDLING STAGE

As water deficit is the major constrained for agriculture crop production, germination potentials of twenty six wheat genotypes were assessed under various drought stress levels while six genotypes were evaluated for drought tolerance potential through growth and physiological studies at early seedling stage. The experimental layout was comprised of three drought treatments in completely randomized pattern with three replicates under controlled conditions. Drought stress was induced through polyethylene glycol-6000 solutions by maintaining three osmotic potentials (-0.5MPa, -0.75MPa and -1.0MPa) in water culture medium while 1/4th Hoagland's solution with zero osmotic potential was applied as control. Germination rate, seedling's growth and photosynthesis were declined with increased levels of water deficiency. Seedling length, fresh and dry biomasses of root and shoot, and photosynthetic pigments executed more reduction at higher water deficit conditions. However, genotype TD-1 followed by ESW-9525 and IBWSN-1010 showed better performance with minimum reduction in seedling's length and biomasses at -0.75MPa and -1.0MPa osmotic stress. TD-1 exhibited least reduction (15.26%) in chlorophyll pigments and enhanced accumulation of K+ ions at highest osmotic stress level. Maximum K+/Ca2+ ratio was determined in ESW-9525 and TD-1 which is the tolerance trait. Hence, TD-1 and ESW-9525 have more drought stress tolerance capacity as compare to other genotypes.