[Effects of potassium-solubilizing bacteria promoting the growth of seedlings under salt stress].

We investigated the effects of potassium-releasing bacteria on physiological and bioche-mical characteristics of (Cultivar Ningqi 1) under salt stress, with an experiment with treatments following randomized block design. The treatments included control (CK), 100 mmol·L NaCl stress (NaCl), 100 mmol·LNaCl stress+KSBGY01 bacteria (NaCl-M1), 100 mmol·LNaCl stress+KSBGY02 bacteria (NaCl-M2), and 100 mmol·LNaCl stress+KSBGY01+KSBGY02 (NaCl-M3). We measued chlorophyll content, polyphenol content, superoxide anion (O) content, hydrogen peroxide (HO) content, soluble sugar content, antioxidant enzyme activity and sucrose metabolic enzyme activity of seedlings. Results showed that the presence of potassium bacteria increased the values of flavonoids (FLAV), fluorescence excitation than anthocyanins relative index (FERARI), anthocyanins (ANTH-RB), nitrogen balance index (NBI-G), decreased the contents of O and HO, and improved soluble sugar content, catalase (CAT) activity, sucrose phosphate synthase (SPS) activity, sucrose synthase (SS) activity and invertase (INV) activity of leaves in seedlings under salt stress. Among all the treatments, the highest values of ANTH-RB and NBI-G, soluble sugar content, and activities of CAT, SPS, SS, and INV presented in NaCl-M2 treatment, the highest values of SPAD, FLAV, and FERARI presented in NaCl-M3 treatment, the highest activity of superoxide dismutase (SOD) presented in NaCl-M1 treatment, the highest activity of glutathione peroxidase (GSH-Px) presented in NaCl treatment, and the highest peroxisome (POD) activity presented in CK. The 14 significant physiological and biochemical indicators in the leaves of seedling were analyzed by grey system correlation degree method. Our results suggested that the weighted correlation degree of phy-siological and biochemical indices of inoculated potassium-solubilizing bacteria was higher than that under CK and NaCl treatments. The highest weighted correlation was observed in NaCl-M2 treatment. Therefore, adding KSBGY02 potassium-solubilizing bacteria could alleviate the salt stress for seedlings.