Isolation, identification and characterization of endophytic fungi of Bambusa oldhamii munro applied as antagonists to Pyricularia oryzae ¹

ABSTRACT

Endophytic fungi, in addition to improving plant development, may produce antimicrobial substances that can inhibit pathogens. The objective of this study was to isolate and characterize endophytic fungi of Bambusa oldhamii and evaluate in vitro antagonism to Pyricularia oryzae. Fungal isolates of B. oldhamii shoots were purified and identified by nuclear ribosomal DNA (nrDNA) including internal transcribed spacer regions (ITS1 and ITS4). These isolates were then confirmed by phylogenetic analysis of the ITS1 and ITS2 sequences and morphological analysis. The isolates were evaluated in in vitro experiments of direct and indirect antagonism (volatile production). Five fungal isolates were identified and named as follows: isolate 27 (Arthrinium sp.); isolate 29 (Acrocalymma sp.); isolate 122 (Botryobambusa fusicoccum); isolate 711 (Phoma sp.) and isolate 712 (Phoma sp.). We found that the area of the P. oryzae colony was reduced by more than 80% by all endophytic isolates in this study, with emphasis on isolate 122, with a 96% reduction in area of the P. oryzae. These results were considered promising and will serve as a foundation for future studies on induction of resistance to P. oryzae.

Keywords:
antagonism; antimicrobial activity; bamboo; bambusicolous fungi