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

A pot experiment was conducted to study the effects of photosynthesis of Chinese cabbage under NaCl stress, and different concentrations of abscisic acid (ABA) solution about 1, 5, 10 and 20 mu mol.L-1 was sprayed, control was sprayed water on leaves. The results showed that spraying ABA could improve the biomass of Chinese cabbage seedling, when the ABA concentration was 5 mu mol.L-1, the plant height, leaf area, fresh weight and dry weight were significantly higher than control; Sprayed low concentration of ABA could increase the photosynthetic pigment content of cabbage seedlings. When the concentration of ABA was 5 mu mol.L-1, the chlorophyll a, chlorophyll b and carotenoids was higher for 6.78% (p < 0.05), 25% (p < 0.05) and 10% (p < 0.05) respectively compared with the control. With the rising of ABA concentration, the activity of antioxidant enzyme increased at first and then decreased, and reached the highest at the concentration of ABA was 5 mu mol.L-1, but the MDA content was lowest. Thus, spraying ABA could improve the biomass, photosynthetic pigment content and antioxidant enzyme activity, reduce MDA content of Chinese cabbage seedling. Thereby, which alleviated damage of salt stress to Chinese cabbage seedling. In this experiment, the best ABA concentration was 5 mu mol.L-1.