Effects of Interaction between Claroideogolmus etuicatum and Bacillus aryabhattai on the Utilization of Organic Phosphorus in Camellia oleifera Abel.

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.

Automated summary

This study found that co-inoculation of arbuscular mycorrhizal fungi (AMF) and phosphate solubilizing bacteria (PSB) can increase the phosphorus content and biomass accumulation of Camellia oleifera plants. Co-inoculation also increased the activities of phosphatase and phytase in the soil and the content of readily available phosphorus. Moreover, AMF colonization and hyphal density were positively correlated with water-extractable phosphorus and bicarbonate-extractable phosphorus, and negatively correlated with NaOH-Po content.