Determination of Agro-Physiological Traits Related to Water Deficit Tolerance for some Soybean Genotypes

Water deficit is the most important abiotic stress limiting soybean production. So find out new genotypes have high water use efficiency with high productivity became an urgent need. A field experiment was conducted during 2018 and 2019 summer seasons to evaluate the performance of six soybean genotypes (H4L4, Giza 83, H3L110, PI 416937, Giza 111 and H6L198) under three irrigation levels (100%, 85% and 70 % of soybean water requirements). Results revealed that, although the lowest seed yield was obtained from PI416937, it recorded the highest contents of relative water (RWC %) and proline along with the lowest and desirable values of leaf temperature and malondialdehyde (MDA) contents. PI416937 recorded the lowest reduction of seed yield under the two deficit irrigation levels (85 % and 70 %). On contrary H4L4 and H6L198 recorded the highest seed yields, chlorophyll pigments and productivity of irrigation water, and water productivity. While, Giza 83 and Giza 111 had the lowest relative water content (RWC), proline, chlorophyll pigments and the highest malondialdehyde (MDA) and seed yield reduction under 85 % and 70% levels respectively. It could be concluded that H4L4, H6L98 and H3L110 had moderate tolerant performance and suitable to cultivate under water deficit conditions (85 % with saving 15 % of water requirement) with yield reduction between 15 to 18 % of seed yield,while PI416937 was identified as a good tolerant genotype and it may be suitable to use in soybean breeding program.