Pathogenic variations in Colletotrichum spp. causing chilli anthracnose in Peninsular Malaysia

In Peninsular Malaysia, Colletotrichum fioriniae, Colletotrichum fructicola, Colletotrichum scovillei, Colletotrichum siamense and Colletotrichum truncatum are the causative pathogens of chilli anthracnose. In the present study, the pathogenic variability and virulence levels of these five Colletotrichum spp. were evaluated. Isolates of C. fioriniae, C. fructicola, C. scovillei, C. siamense and C. truncatum were tested for pathogenicity using red and green Capsicum annuum and red and green Capsicum frutescens. Pathogenicity tests were conducted using spore suspensions and mycelial plugs on wounded and nonwounded chilli fruits. All isolates tested on the wounded chilli fruits caused anthracnose symptoms with variable disease severity and virulence. In nonwounded chilli fruits, only isolates of C. scovillei (n = 7) and C. truncatum (n = 5) caused infection. C. fioriniae, C. fructicola, C. scovillei, C. siamense and C. truncatum showed variability in pathogenicity and virulence levels in red and green chilli fruits of Ca. annuum and Ca. frutescens. Pathogenicity tests on wounded and nonwounded chilli fruits can be used to identify pathotypes within anthracnose pathogen populations. This is important for strategizing the effective disease management of chilli anthracnose.