Morphological, cultural and genetic variabilities in fruit rot of Chilli caused by Colletotrichum capsici in Tropical region of South India

Twenty isolates of Colletotrichum 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 20 isolates on an indigenously developed differential set of Capsicum cultivars indicated the existence of different virulences in chilli populations. Pathotype Cc-1 was most virulent and attacked all the differential cultivars. 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.