Influences of seasons, tissue types and locations on endophytic fungi diversity associated with Terminalia bellirica (Gaertn.) Roxb.

Terminalia bellirica is a traditional medicine plant used in various parts of the world. It has several properties, such as antimicrobial, and antioxidant, boosts immunity, regulates diabetes, and treats asthma, etc. Endophytic fungi reside within the plant tissue without causing plant disease symptoms. Endophytic fungi produce secondary metabolites that might play a pivotal role in conferring these pharmacological activities. Therefore, the present study was performed to unearth the novel endophytic fungi with seasonal influence from T. bellirica. A total of 643 endophytic fungal isolates were recovered from the leaves, barks, and roots of T. bellirica in three different seasons and identified at morphological levels. During the study, 26 culturable endophytic fungi including the non-sporulating forms belonging to 14 genera, 8 families, and 4 classes, were obtained. Ascomycota was found to be dominant (93%) and Mucoromycota (2%) was the least. The maximum isolate belongs to Sordariomycetes showing 47%. The isolation rate was found maximum in the root segments (0.62), while the colonization rate was recorded highest in the leaves (100%). However, the fungal endophytes were recovered maximum at Suryamaninagar (S1) site (180) followed by Debasthal (S5) site (147) and the least isolates were recovered at Ampinagar (S3) site (100). During the summer season, the highest total colonization frequency (CF) was detected by Aspergillus niger (124%) and Colletotrichum gloeosporioides in monsoon (156%) and winter seasons (92%). The maximum fungal isolates were obtained during the monsoon season (286) followed by the summer (202) and winter seasons (155). The colonization rate was higher during the monsoon season as compared to winter and summer, whereas the maximum isolation rate was recorded during the monsoon (0.76) than summer (0.54) and winter (0.41) seasons, respectively. The type of tissue, sampling locations, and seasons influences the endophytic fungal diversity and composition in this plant. Species diversity of endophytic fungi was found to be maximum during the monsoon season and minimum during the winter. The endophytic fungi recovered from this plant might be further explored for their biological activities, anticancer drugs, pharmaceutical and agricultural fertilizers, and may be used commercially.