The inducing effect of chitosan on heat resistance of Phalaenopsis seedlings
This study aims to assess the effect of chitosan on heat resistance of Phalaenopsis seedlings.Phalaenopsis seedlings were treated with chitosan at 0 (without chitosan addition as control), 25, 50, 100, 200, 400 mg · L-1 respectively, at 42 ℃ for 3 days, and then the physiological changes in Phalaenopsis seedlings were determined.The results showed that with increasing the chitosan concentration from 25 to 100 mg · L-1 , the activities of superoxide dismutases (SOD), peroxidases (POD) and catalase (CAT), and the contents of proline, soluble sugar, total chlorophyll and carotenoid in Phalaenopsis seedling leaves increased gradually, while the membrane permeability and malondialdehyde (MDA) content of the leaves declined gradually, but no significant change was found in the content of soluble protein.In treatment with 100 mg · L-1 chitosan, the activities of SOD, POD and CAT and the contents of proline, soluble sugar, total chlorophyll and carotenoid in Phalaenopsis seedling leaves reached their peak values and were significantly higher than those of the control (P＜0.01), whereas the membrane permeability and MDA content of the leaves showed the lowest values and were significantly lower than those of the control (P＜0.01), and the Phalaenopsis seedlings suffered a slight heat injury.With increasing chitosan concentration from 200 to 400 mg · L-1 , the activities of SOD, POD and CAT, and the contents of proline, soluble protein, soluble sugar, total chlorophyll and carotenoid of the leaves decreased significantly (P＜0.01), whereas the membrane permeability and MDA content of the leaves increased significantly (P＜0.01), and Phalaenopsis seedlings tended to suffer more serious heat injury.According to the results obtained, it is concluded that treatment with 100 mg · L-1 chitosan can significantly improve heat-resistance of Phalaenopsis seedlings.
国家科技期刊平台
NSTL
万方数据
维普
