Effect of Drought Stress and Methanol on Chlorophyll Parameters, Chlorophyll Content and Relative Water Content of Soybean (Glycine max L., var. L 17)

In order to investigate the effects of methanol application on some physiological properties of soybean under low water stress, a factorial experiment was conducted at Research Field of Faculty of Agriculture and Natural Resources, Islamic Azad University-Karaj Branch, Karaj, Iran, during 2008, based on a randomized complete block design with three replications. The first factor was consisted of different levels of methanol equal to 0 (control), 7, 14, 21, 28 and 35 volumetric percentage (v/v), which were used as foliar applications at three times during growth season of soybean, with 15 days intervals. The second factor was water stress conditions in two levels, based on depletion of 40 and 70% of available soil moisture. Some traits such as grain yield (GY), relative water content (RWC), chlorophyll fluorescence parameters, and chlorophyll content were measured, one day before and after the third methanol application. Results showed that chlorophyll content (Chl), GY, electrolytes leakage (EL) at second sampling, photochemical capacity of PSII (Fv/Fm), maximum and variable fluorescence (Fm and FV, respectively) were affected by water stress significantly