Variability in Biochemical Traits Associated with Drought and Heat Tolerance in Wheat Genotypes under Different Irrigation Levels

The present investigation was carried out under three levels of irrigation i.e. I₀ (No irrigation), I₁ one irrigation (CRI) and I₂, two irrigations (CRI + Flowering) involving 10 wheat genotypes viz, K7903, K9162, K9351, K9465, K8962, K9423, K0307, NW1014, K9533 and HD2733. Results revealed that wheat genotypes viz, K9351, K8962, K9465, K0307, K9162 and NW1014 recorded higher nitrate reductase (NR) activity, superoxide dismutase (SOD), total soluble sugar and proline content in leaf as compared to other genotypes under all levels of irrigation. Irrigation level i.e. I₀ (No irrigation) had deleterious effect on almost all the above mentioned traits as compared to I₁, one irrigation (CRI stage) and I₂, two irrigations (CRI and Flowering stage). Thus, these traits which are simple and easily measurable can be used for screening of wheat genotypes for drought and heat tolerance. Genotypes such as K9351, K8962, K9465, K0307, K9162 and NW1014 were found better performer in respect of above traits under different levels of irrigation as compared to other genotypes. Therefore, these genotypes can be used as suitable donors in breeding programme to develop new drought and heat tolerant genotypes.