Arbuscular mycorrhizal fungi (AMF) and phosphate solubilizing bacteria (PSB) are involved in phosphorus (P) mobilization and turnover; however, the impact of their interaction on plant P absorption and organic P mineralization in the hyphosphere (rootless soil) are unknown. This study examined the interactive effects of two native microorganisms, namely Claroideogolmus etuicatum and Bacillus aryabhattai, and the effects of co-inoculation of both microorganisms on organic P mineralization and the subsequent transfer to Camellia oleifera, using a three-compartment microcosm with a nylon mesh barrier. The results demonstrated that the co-inoculation treatment (AMF + PSB) significantly increased the plant P content and biomass accumulation in C. oleifera compared to those of the non-inoculated control. Furthermore, co-inoculation boosted soil phosphatase and phytase activities as well as the liable P content. Compared to the non-inoculated control, inoculation of AMF decreased the NaOH-Po content. A correlation analysis showed that AMF colonization and hyphal density was significantly positively correlated with H2O-P and NaHCO3-Pi and negatively correlated with NaOH-Po. It was shown that co-inoculation could increase phosphatase activity, phytase activity, and promote the liable P content, thus increasing the phosphorus content and biomass accumulation of C. oleifera. In conclusion, AMF and PSB interactively enhanced the mineralization of soil organic P, and therefore positively affected P uptake and plant growth.
Keywords: arbuscular mycorrhizal fungi; oil tea; phosphate solubilizing bacteria; phosphorus mobilization.