Effects of Exogenous Abscisic Acid on the Growth and Physiological Properties of Chinese Cabbage Seedlings under AlCl3 Stress

A pot experiment was conducted to study the effects of photosynthesis of Chinese cabbage under AlCl3 stress, and different concentrations of abscisic acid (ABA) solution about 1, 5, 10 and 20 mu mol.L-1 were sprayed, control was sprayed water on leaves. The results showed that sprayed ABA could improve the plant height and leaf area, dry weight and fresh weight of Chinese cabbage seedlings under AlCl3 stress, and with the rising of ABA concentration, which was raised first and then reduced. Compared with control, when the ABA concentration was 10 mu mol.L-1, the height, leaf area, dry weight and fresh weight of cabbage seedling was increased by 15.69% (p < 0.05), 31.86% (p < 0.05), 40.11% (p < 0.05) and 38.46% (p < 0.05) respectively; total chlorophyll content, carotenoid content increased 37.01% (p < 0.05) and 29.78% (p < 0.05) respectively; the SOD activity and CAT activity increased 11.24% (p < 0.05) and 74.02% (p < 0.05) respectively. Thus, exogenous ABA could improve the biomass, photosynthetic pigment content, antioxidant enzyme activity and reduce MDA content of Chinese cabbage seedling, and the optimal concentration of ABA was 10 mu mol.L-1.