Changes in pectinase and cellulase activity of Colletotrichum capsici mutants and their effect on Anthracnose disease on capsicum fruit

Abstract

Colletotrichum capsici was identified as a major pathogen that causes Anthracnose disease on capsicum (Capsicum frutescence L.), fruits accounting for 25 – 30% post-harvest loss during storage and marketing. The infection was found to be latent in nature. Towards understanding the latent nature of the pathogen, experiments were carried out to obtain non-pathogenic strain of C. capsici by UV radiation treatment. Exposure of three days old mycelial mat to UV light (312 nm wavelength at 12 in distance from the source) for 15, 30, 45, 60, 75 and 90 minutes was tried. The UV light exposure for 45 minutes was found to be optimum to get less virulent pathogenic strain of C. capsici. It showed a reduction in 42.86% cellulase and 40% pectinase activity. The reduction in activity of these enzymes resulted in 3.5 days delay in manifestation of Anthracnose disease and also reduces the rate of spreading of disease. The UV treatment was found to reduce 40% of the vegetative growth of fungi and 10% decrease in the production of number of conidia. However, no linear response was obtained with increase in dosage of UV treatments.

Keywords:

• Capsicum frutescence L.
• Anthracnose
• Colletotrichum capsici
• UV light and Mutant