Isolation and Identification of Endophytic Fungi from Oroxylum indicum (L.) Vent. and Preliminary Study on Its Growth Promoting Function

Purpose To analyze the species and growth promoting functions of endophytic fungi in Oroxylum indicum (L.) Vent.

Methods Endophytic fungi were isolated from the bark, seeds, pericarps and leaves of O. indicum, and the growth promoting activity of the isolated endophytic fungi was analyzed according to physiological indexes. Some representative endophytic fungi were selected and transferred to soybean plants for culture, and the actual growth promoting effect was verified by soybean yield index.

Results A total of 50 endophytic fungi were isolated from bark, seeds, pericarps and leaves of O. indicum, belonging to 13 genera and 23 species. Among them, the most isolated strains were from peels, and Colletotrichum was the dominant genus. Nine representative fungi had the ability to produce indole acetic acid and nitrogen fixation, and six fungi had the characteristics of phosphorus and potassium dissolution. Transfer cultivation showed that the pod number of soybean increased by 5%-75% and the yield increased by 37%-231%, among them, Penicillium crustosum had the best growth promoting effect.

Conclusion The first study on the isolation of endophytic fungi from O. indicum is carried out, and the function of the isolated endophytic fungi are verified, among which P. crustosum has the best effect in growth promoting and improve the number of pods and yield of soybean after transfer to soybean, which has the potential to be developed as microbial fertilizer.