Ceylon Journal of Science (Sep 2019)
Characterization of fungal pathogens causing anthracnose in capsicum pepper (<i>Capsicum annuum</i> L.) and their seed borne nature
Anthracnose caused by Colletotrichum spp. is a troublesome disease in all Capsicum spp. including capsicum pepper (Capsicum annuum L.), causing severe losses at both the pre-harvest and post-harvest stages. It is common throughout the world. In Sri Lanka, capsicum pepper is likely to be infected by both Colletotrichum capsici (Colletotrichum truncatum) and C. gloeosporioides, resulting in a reduction in the quantity and quality of the harvest. A detailed investigation was carried out to identify the different species of Colletotrichum that infect capsicum pepper, and the nature of this infection by employing standard tests. Colletotrichum capsici and C. gloeosporioides were isolated from the capsicum pepper seed samples collected from three different agro ecological regions in Sri Lanka. When capsicum pepper seeds collected from fruits categorized according to a standard rating scale were tested for germination, a gradual decrease of germination percentages and increased seed infection percentages were observed. After culturing different components of the seeds collected from infected fruits, it was found that both C. capsici and C. gloeosporioides can survive on the seed coat, pericarp and embryo. In addition, Fusarium spp. and Aspergillus spp. were also present in cultures of seed coat but not in cultures of the pericarp and embryo. The study revealed that both C. capsici and C. gloeosporioides can invade the important parts of the seeds internally and externally, causing higher germination losses, during both the pre and post emergence stages of capsicum pepper; the Aspergillus spp. and Fusarium spp. were only seed borne externally.