INFECTION PROCESS OF ANTHRACNOSE BY Colletotrichum truncatum ON PAPAYA MARADOL

ABSTRACT Colletotrichum truncatum is a pathogenic fungus causing anthracnose in papaya fruit (Carica papaya L.) and responsible for losses on postharvest. The purpose of this workwas to induce the infection process of C. truncatum on fruit of papaya cv. Maradol under controlled conditions and to describe the disease progress by histopathological and light microscopy tools in order to elucidate the pathogen life cycle. Direct cuticle penetration by appresoria occurred around 30 h after inoculation (hai); the intramural hyphae grew on the epidermic cell wall layer at 30-48 hai;necrotrophic colonization started at 72 hai; intracellular hyphae grew into parenchymal cells causing extensive cell wall degradation in association to water-soaked lesions production. The time for the host cuticle breakdown occurred between 96-148 hai. The pathogen life cycle was completed at 96 hai with acervuli formation. Microscopic observations on papaya fruits revealed that C. truncatum is a subcuticular intramural pathogen.