Evaluation of the antagonistic activity of Trichoderma spp. against Colletotrichum spp. causing anthracnose in chili pepper under in vitro

Abstract

Colletotrichum is an important genus of plant-pathogenic fungi that infects a wide range of host plants. Colletotrichum spp. causes diseases such as anthracnose, leading to significant economic losses in agriculture. Trichoderma spp. is a common soil fungus with antagonistic activity against various plant pathogens, including Colletotrichum spp., the causal agent of anthracnose in chili pepper. To identify Trichoderma spp. with high antagonistic activity against anthracnose, three soil samples were collected from skyward pointing chili pepper growing areas in Phu My District. Based on morphological characteristics, four Trichoderma spp. strains were isolated, and two strains with high antagonistic activity against anthracnose were selected. Among them, Tr.1 and Tr.2, exhibited high antagonistic indices of 74,78% and 85,44%, respectively, under in vitro conditions. ITS sequence analysis identified Tr.1 as T. viride and Tr.2 as T. asperellum. These two antagonistic strains hold promising potential for biological control of anthracnose in skyward pointing chili pepper.