Isolation and identification of antagonistic fungi of fungi associated with chili wilt in southern Guanajuato, Mexico

Abstract

The chili crop (Capsicum annuum) in Mexico represents an important economic source; however, every year there are losses in production of 40 to 100% due to the root disease known as wilt, which causes premature death of plants, this disease is caused by the fungi complex formed by Rhizoctonia solani, Fusarium oxysporum, Fusarium solani and Phytophthora capsici. The objective of this research was to isolate antagonistic fungi to the pathogens causing wilt from soil samples obtained in the southern of the state of Guanajuato, Mexico. Antagonistic fungi potential against Rhizoctonia spp., Fusarium spp. and Phytophthora spp. were isolated. Then three fungi isolates presented antagonistic potential, inhibiting mycelial growth by 41 to 83%. Molecular identification of the antagonist fungi was performed by amplifying the intergenic transcriptional regions (ITS) of the 18S ribosomal DNA component of fungi. This research contributes to the study of biological control of root pathogens using beneficial native microorganisms present in crop soils affected by pathogens associated with chili wilt in southern Guanajuato, Mexico.