[Effects of silicon on photosynthesis and antioxidative enzymes of maize under drought stress]

With pot experiment, this paper studied the effects of silicon supply on drought-resistance capability of maize plant. The results showed that under mild and severe drought stress, supplying silicon could increase the plant biomass by 31.1%-33.3% and 23.7%-40.5%, respectively, compared with the control. Silicon enhanced the net photosynthetic rate by 10.9% --28.8%, increased the chlorophyll content and POD, SOD and CAT activities by 4.0% -11.9%, 6.4% -26.4%, 17.8% -26.8% and 3.2%-33.5%, respectively, and restrained the increase of leaf plasma membrane permeability and MDA content. Correlation analysis indicated that there was a significant correlation between plant dry matter accumulation and diurnal photosynthetic cumulates (r = 0. 9357, P < 0.05), demonstrating that the enhancement of photosynthesis under effect of silicon supply was the main factor inducing the increase of dry matter accumulation under drought stress. The higher antioxidative enzyme activities with silicon supply lightened the injury effect of free radicals, being another important factor inducing the increase of plant drought-resistance capability.