Screening and Related Characteristics of Rhizosphere Phosphorus-soluble Fungi in Fritillaria taibaiensis

Objective The aims were to screen high-efficient phosphorus-soluble fungi strains from the rhizosphere soil of Fritillaria taibaiensis from different producing areas, and to provide strain resources for the development of bacterial fertilizer in the cultivation process of Fritillaria taibaiensis.

Method The phosphorus (P) solubilizing strains were screened by the P solubilizing ring method, and the high-efficient P solubilizing fungal strains were selected by the molybdenum antimony resistance colorimetric method. The colony morphology and ITS amplified sequence were identified. The P solubilization ability of the selected strains under different P source liquid medium was studied.

Result A total of 29 P solubilizing fungi were isolated from rhizosphere soil samples of Fritillaria taibaiensis, and 3 highly effective P solubilizing strains ES-2, GY-2 and TB-1 were obtained through primary screening and rescreening. The three strains were identified as Aspergillus tubingensis, A. niger and A. fumigatus. In the liquid medium with tricalcium phosphate as the P source, the effective P increase of each strain reached the maximum value at 96 h, and the effective P increase of strain ES-2 was 281.04 mg L⁻¹, GY-2 was 274.24 mg L⁻¹, and TB-1 was 193.28 mg L⁻¹. The dissolving ability of all strains to different P sources was tricalcium phosphate > inorganic iron P > zinc phosphate hydrate > aluminum phosphate > hydroxyapatite.

Conclusion In this study, 3 strains of highly efficient P soluble fungi were obtained, which could dissolve 5 kinds of insoluble P sources at the same time, and provide strain resources for the development of microbial P soluble bacterial fertilizer in the field production of Fritillaria taibaiensis.