Evaluation of morphological and physiological traits of wheat (Triticum aestivum L.) cultivars under Flooding stress conditions and its relationship with grain yield

Flooding stress is one of the most important stresses related to autumn plants especially in the northern parts of the country. The most cost-effective and reliable way to reduce the effects of environmental stresses on crops is to choose a resistant cultivar. Therefore, this experiment was conducted to investigate Flooding stress tolerance in wheat genotypes using some morphological and physiological characteristics and its relationship with grain yield. This experiment was conducted as a factorial experiment in a completely randomized design with 3 replications and two factors: 1) Flooding stress (non-flooding and 15 days flooding) and 2) cultivar (20 cultivars) at Gorgan University of Agricultural Sciences and Natural Resources in 2016-17. Done. Based on the results of this experiment, the highest grain yield was observed in N-80-19, N-87-20 and N-91-14 under non-stress conditions, which were 1.95 and 1.88 g pl-1, respectively. Under flooding conditions, the highest grain yield was obtained in N-80-19 (1.02 g pl-1) and Kohdasht (0.96 g pl-1) cultivars. The results showed that leaf area, leaf dry weight, chlorophyll a and b, root volume and dry weight, carotenoid and SPAD were affected by the destructive effects of Flooding stress and were significantly reduced under non-stress conditions. Leaf area had the highest correlation (0.89) with grain yield, after leaf area, chlorophyll a and SPAD had the highest correlation with grain yield. Based on the results of this experiment, it can be concluded that leaf area, photosynthetic pigments, SPAD number and root volume in wheat genotypes were highly correlated under water stress conditions with wheat grain yield, Therefore, genotypes with more photosynthetic leaf area at vegetative stage can be identified as resistant genotypes to Flooding stress. Carotenoid and SPAD were affected by the destructive effects of Flooding stress and were significantly reduced under non-stress conditions. Leaf area had the highest correlation (0.89) with grain yield, after leaf area, chlorophyll a and SPAD had the highest correlation with grain yield. Based on the results of this experiment, it can be concluded that leaf area, photosynthetic pigments, SPAD number and root volume in wheat genotypes were highly correlated under water stress conditions with wheat grain yield, Therefore, genotypes with more photosynthetic leaf area at vegetative stage can be identified as resistant genotypes to flooding stress.