The Effects of Sap of Nitraria Plant on the Growth of Its Endogenous Nitrogen-fixing Microbes under Saline-Alkaline Stress

摘要

The endophytic N-fixing microbes Klebsiella oxytoca NHglj1, Klebsiella oxytoca NHglj2 and Enterobacter asburiae LMw107 of Nitraria were selected to explore the effect of Nitraria schoberi L. plant sap on salt and alkali resistance of its 3 endogenous N-fixing microbes strains in the Winogradsky's N-free medium under different salinity and alkalinity gradient. The results show that the NaCl tolerance of 3 strains is 0 ～ 4% and 3 strains can all survive in pH 6 ～ 13. After sap of Nitraria is added, the salt resistance of NHglj1 decrease, the colony diameter of K. oxytoca NHglj1 is 59% ～ 82% that of control, the change of alkali resistance of NHglj1 is similar to that of the salt resistance, the diameter of NHglj1 is 13% ～58% that of control (P<0.05). However, the salt resistance of NHglj2 and LMw107 increase, the diameter is larger than 2% ～ 45% that of the control. The alkali resistance of NHglj2 and LMw107 also increase in pH6～13. The results exhibit that Nitraria sap may partially improve salt-alkali resistance of parts of endogenous N-fixing microbes.