Effects of the Combined Application of Selenium and Hydrogen-enriched Water on the Growth and the Structure of Rhizosphere Bacterial Community of Mung Bean Seedlings under Salt Stress

To investigate the effects of combined application of selenium and hydrogen-enriched water on the growth of mung bean seedlings and the structure of soil bacterial community in rhizosphere under salt stress, Jinlü 8 was chosen as the experimental material for pot experiment in this study. The effects of the combined application of different concentrations of selenium (2.5, 5.0 and 7.5 mg·kg^-1) and hydrogen-enriched water ( 25%, 50% and 100%) on the physiological and biochemical indexes of mung bean seedlings and the structure of soil bacterial community in rhizosphere under the stress of NaCl with 1.5 g·kg^-1were studied. The results show that: (1) Compared with the control, the plant height, root length, and the activities of chlorophyll content,POD, CAT and SOD in the leaves of mung bean seedlings were significantly inhibited under salt stress. (2) Compared with salt stress, the combined application of different concentrations of selenium and hydrogen-enriched water was found to be effective in promoting the plant height and root length, increasing the chlorophyll content of leaves, enhancing the activities of POD, CAT and SOD, and reducing the content of malondialdehyde. (3) The combined application of selenium and hydrogen-enriched water with different concentrations had a certain effect on the structure of soil bacterial in rhizosphere under salt stress. T8 (7.5 mg·kg^-1 + 50%) and T9 (7.5 mg·kg^-1 + 100%) treatments significantly increased the diversity and richness of soil bacterial communities in rhizosphere under salt stress. The ACE index and the Chao1 index increased by 24.51% , 19.67% and 24.75%, 19.97%, respectively. The combined application of different concentrations of selenium and hydrogen-enriched water could effectively alleviate the stress of salt on mung bean seedlings and improve the structure of soil bacterial community in rhizosphere. The combined application of 7.5 mg·kg^-1 sodium selenite and 50% hydrogen-enriched water had the best effect on alleviating salt stress in mung bean seedlings.