Morphological, pathogenic and genetic variability in <i>Colletotrichum capsici</i> causing fruit rot of chilli in Tamil Nadu, India

Abstract

Chilli (Capsicum annuum L.) fruit rot disease caused by Colletotrichum capsici under tropical and subtropical conditions, results in qualitative and quantitative yield losses. Twenty (20) isolates of C. capsici were collected from conventional chilli growing areas of Tamil Nadu. In culture, most of the isolates produced cottony, fluffy or suppressed colonies. However, no significant differences were noticed in shape and size of conidia. The reaction of the 20 isolates on an indigenously developed differential set of Capsicum cultivars indicated the existence of different virulences in Tamil Nadu chilli populations. The genetic relationship between 20 morphological groups recognized within C. capsici was investigated using random amplified polymorphic DNA (RAPD) analysis. Molecular polymorphism generated by RAPD confirmed the variation in virulences of C. capsici and different isolates were grouped into two large clusters. The pathological and RAPD grouping of isolates suggested no correlation among the test isolates.

Keywords: Chilli, Colletotrichum capsici, variability, RAPD

African Journal of Biotechnology, Vol 13(17), 1786-1790