Differential Reactions on Mature Green and Ripe Chili Fruit Infected by Three Colletotrichum spp.

Abstract

Differential reactions on mature green and ripe chili fruit of 10 genotypes from four cultivated Capsicum spp. (i.e., Capsicum annuum, C. baccatum, C. chinense, and C. frutescens) were investigated after being inoculated with 33 isolates of Colletotrichum capsici, C. gloeosporioides, and C. acutatum originating from Thailand. The inoculation was performed using an injection method. Differential reactions, based on qualitative host reactions (i.e., lesion development versus no infection) grouped the Colletotrichum isolates into different pathotypes. C. capsici was grouped into three pathotypes based on differential reactions on ripe fruit stage of two Capsicum chinense genotypes (PBC932 and C04714) and two pathotypes based on differential reactions on mature green fruit stage of C04714. Colletotrichum gloeosporioides was grouped into five and six pathotypes on their reactions in ripe and green fruit maturity stages, respectively. C04714 and two Capsicum annuum genotypes (Jinda and Bangchang) acted as differential hosts with ripe fruit, whereas C04714 with all C. annuum and C. frutescens genotypes acted as differential hosts with green fruit. No pathotype of Colletotrichum acutatum was identified on ripe fruit but three pathotypes were identified on green fruit based on differential reactions in two Capsicum baccatum genotypes (PBC80 and PBC81).