Physiological Studies on Six Wheat (Triticum Aestivum l.) Genotypes for Drought Stress Tolerance at Seedling Stage

Abstract

Screening of drought tolerant varieties of wheat are important for ameliorating productivity of water scarce areas. Six wheat genotypes including two local checks were evaluated for drought tolerance against different osmotic stress levels induced by Polyethylene Glycol (PEG)6000. Experiment was set in completely randomized design (CRD) with three replicates and four treatments [0, -0.5 MPa, -0.75 MPa and -1.0 MPa PEG concentrations]. Wheat genotypes Khirman and Chakwal-86 were employed as check varieties. Four test genotypes evaluated were SD-621, SD-222, NIA Saarang and 22-03. Data were recorded on various seedling parameters such as germination percentage, germination index, shoot length, root length, fresh and dry weight of shoot and root, chlorophyll contents (a and b) and ionic contents (K+ and Ca2+, and K+ /Ca2+ ratio). No seedling survived at -1.0 MPa osmotic stresses. Best results were illustrated by wheat genotypes SD-222 and SD-621 with 98.89% and 96.7% germination at -0.5MPa and -0.75MPa osmotic stress, respectively. NIA Saarang and genotype 22-03 also exhibited better results at moisture stress. Reduction in chlorophyll and ionic contents was occurred with rise in water deficit in all genotypes. These findings appreciate the future use of these genotypes for obtaining high yield in water sparse areas.