Evaluation of the effect of drought stress on some characteristics of germination and seed germination of four commercial soybean cultivars produced under low irrigation conditions with a standard germination test.

In order to evaluate the effect of drought stress on some characteristics of germination and seed set of commercial soybean cultivars under water stress in the research farm of Karaj Seedling and Seed Breeding Research Institute, an experiment was conducted in 1400 using a standard germination test in the laboratory. The seed analysis of Karaj Seed and Seedling Registration and Certification Research Institute was carried out factorially in the form of randomized complete block design with 4 replications. The treatments include applying 4 levels of dry stress of polyethylene glycol 6000 with potentials of 0 (no stress), 3-, 6-, and 9-MPa, on the seeds of 4 commercial soybean cultivars, Williams, Hamilton x Essex, TMS, and Bunty, produced at 3 levels. The low irrigation stress of the mother plant, irrigation after the values of 50 (optimal irrigation and control), 100 (mild stress) and 150 (severe stress) mm of evaporation from the evaporation pan were class A). The examined characteristics include: percentage of final germination, percentage of normal seedlings, percentage of abnormal seedlings, percentage of hard seeds, percentage of rotten seeds, average daily germination, average germination time, seedling length and index The length and weight of the seedlings were. The results showed that the mutual effect of drought stress, low irrigation stress and variety had a significant effect on all the examined characteristics. In the treatment of 9-MPa drought stress and without water deficit stress, the Williams variety compared to the treatment without drought stress and without water deficit stress, the average germination time was 0.90 days, the percentage of rotten seeds, hard seeds and abnormal seedlings were 0.18%, 750 respectively. 5.5% and 0.60% increase and average daily germination of 1.28 days, final germination and normal seedling decreased by 1.28% and 4.92%, respectively. In general, among the studied cultivars, Williams variety showed the best and Bunty variety showed the weakest response to low irrigation and drought stress.