Evaluation of Hexaconazole effects on some physiological indices to water deficit stress tolerance in two soybean cultivars

In order to investigate the effect of Hexaconazole (HEX) on the increasing tolerance to water deficit stress of two soybean (Glycine max L.) cultivars, an experiment was conducted in Faculty of Agricultural of Tarbiat Modares University as factorial experiment in randomized complete blocks design arrangement. Factors in this study were included soybean cultivars (L17 and Clark63), HEX concentration (0 and 35 mg/L) and water deficit stress levels (optimum irrigation and water deficit stress on 40% Fc). HEX treatment was applied as soil application method at flowering stage and after HEX application the plants were subjected to water deficit stress. Results showed that water deficit stress significantly enhanced proline content, glucose, anthocyanine, superoxide dismutase and proxidase activity but reduced chlorophyll a, b, total, carotenoid and soluble protein. Clark63 was more tolerant than L17. The results indicated that HEX treatment increased the chlorophyll content under water deficit stress condition. Under water deficit condition, HEX treatment relieving effects of stress that proline and glucose in response to HEX decreased. Under optimal irrigation, the proxidase and superoxide dismutase activity increased in both cultivars by HEX application but under water deficit condition the superoxide dismutase and peroxidase activities increased by HEX application in L17 and clark 63 respectively.