Evaluation of drought tolerant wheat genotypes using morpho-physiological indices as screening tools

摘要

As water is the major limiting factor for agricultural crop production in arid and semi - arid areas, hence, twenty six wheat genotypes were screened under terminal drought stress for assessing their desiccation tolerance potentials. Experiment was conducted in completely randomized design (CRD) with three replicates and two irrigation treatments (control and terminal drought). Water scarcity had significantly reduced growth and yield contributing attributes while six genotypes performed relatively better under drought stress. Highest germination potentials (62.66%) were observed in MAS-20/2014 at -1.0 MPa osmotic stress under control conditions. However, genotype MAS-3/2014 exhibited maximum grain yield (23.32 g plant -1 ) while MAS-20/2014 showed minimum reduction (15.70%) in grain yield under drought stress. Physiological studies highlighted that better yielding genotypes exhibited relatively less reduction in chlorophyll contents (5.93% ) in MAS-20/2014, nitrate reductase activity (6.70% )in MAS-11/2014 and osmotic potentials (0.769 MPa) in MAS-3/2014, while more relative increase in proline accumulation (83.35% ) in MAS-20/2014 , glycine-betaine (92.43%) in MAS-3/2014, total soluble sugars (36.65%) in MAS-23/2014 and potassium contents (3.66%) in MAS-6/2014 were analyzed under drought. These findings illustrated that wheat genotypes MAS - 2/2014, MAS - 3/2014, MAS - 8/2014, MAS - 12/2014, MAS - 18/2014 and MAS - 20/2014 exhibited better tolerance under drought conditions making them suitable for enhancing the productivity of rain fed and arid areas.