Variability in Colletotrichum infecting chilli plants of Andaman and Nicobar Islands, India

ABSTRACT

Aim: The aim of the present study was to understand the basic pathogen dynamics of Colletotrichum species infecting chilli crop in the Andaman and Nicobar Islands for disease management practices. Methodology: Twenty fungal isolates associated with chilli (Capsicum annuum) anthracnose disease from diverse locations of tropical Andaman, India were characterized using polyphasic approaches. Results: Upon morphological studies, out of twenty isolates, fourteen isolates were found chromogenic and eleven showed concentric ring pattern of mycelial growth. Based on conidial morphology, the isolates were grouped into two species (C. capsici and C. gloesporioides). The pathogenicity tests on three chilli varieties revealed difference in the pathogenic potential among the collected isolates. The sequence analysis using internal transcriber spacer (ITS) region revealed the presence of two other species C. siamense and C. plurivorum, in addition to C. gloesporioides and C. capsici. Interpretation: The present study revealed the presence of high level of genetic and pathogenic variability among the Colletotrichum isolates infecting chilli in Andaman Islands.