Characterization and Pathogenicity of Colletotrichum Species Associated With Anthranose in Srilankan Chilli Papper

Abstract

Anthracnose disease is one of the more significant economic constraints to chiliproduction worldwide, especially in tropical and subtropical regions. Anthracnose is mainly a problem on mature fruits, causing severe losses due to bdtn pre- and post-harvest fruit decay- Colletotrichum acutatum was identified as a causal organism of chili anthracnose, a problematic disease of chilli in Sri Ldfika . C. gtoeosporioidesand C. capsici have previously been reported as causal agents of chili anthracnose. ln the present study, C.acutatum was isolated from anthracnose lesions of,ohilipepper (Capsicu.m annuum),cvs. Hungarian Yellow (HY) and CA-8 and identifigd using conidial morphology an'd sensitivityto fungicides. The colony of the isolate obtained was white to.orange.in colour, with slight shades of pink and light mouse-grey aerial mycelium. Pathogenicity of this pepper isolate of C.acutatum was proved by inoculating wounded and non-wbunded peppers of both cultivars and fulfilling Koch's postulates. Th6 results revealed that the C.acutatum can produce anthracnose lesions onrboth ryounded and.non-wounded fguits. Symptom development was slower in the non-wounded fruits. Further, the resultsif the fungicide assay indicated that the C.acutatum was less sensitive to benomyl{Benlate) while, C. gloeosporiordes isolate from pepper was extremely sensitive to -this fungicide at all concentrations used. Based on these findings, we propose that, at present, C. acutatum is a major contributing cause of anthracnose of chilli peppers i4 sri Lanka.