Biological characterization of Colletotrichum fungi from cultivated chilli in Cu Chi, Ho Chi Minh City

Abstract

   Anthracnose caused by various species of Colletotrichum causes significant damage to chilli crop (Capsium annuum L.). At Cu Chi district, Ho Chi Minh City, the disease can occur on pre-harvest fruit in the rainfall season and typical symptoms include dark, sunken, and circular lesion with dark brown conidial masses. Two Colletotrichum species have been identified almost based on morphological and cultural characteristics. Isolates were obtained from diseased fruit, grown on potato glucose agar (PGA) at 25-300C for 5-7 days and evaluated for macro and microscopic cultural characteristics. The cultures developed black acervuli around the center of the colony. Colonies on PGA were white, light pink turning light gray with age or greenish gray. Conidia were hyaline, unicellular and cylindrical with obtuse apices and tapering bases, resembling both C. capsici and C. gloeosporioides. The optimum temperature for growth of C. capsici and C. gloeosporioides was at 25-300C, less growth was observed 200C or 35 0C.