Study on Necrotrophic Characterstic of colletotrichum capsici on Cowpea Seedlings

Colletotrichum spp. which causes anthracnose diseases in plants is a hemibiotrophs termed by Luttrell (1974), which uses both biotrophic and necrotrophic modes of nutrition at different stages of their development. Literature observes that, after an initial biotrophic phase of varying duration, these fungi switch to necrotrophy which leads to death of the affected tissues (which causes water soaked lesions and holes) and severe infection results in death of the entire plant body. It is observed from the literature that, causal agent of chilli anthracnose C. capsici, nectrotrophic behaviour is less reviewed for its interaction with other plants. This paper, studies to understand the establishment of pathogenecity of C. capsici on the host plant, cowpea. This success leads to necrotrophic characteristic of the fungi C. capsici. The study observed that, after an inoculation of conidial suspension artificially in lab on seedlings of cowpea other than its specific host chilli with sprayer, susceptible tissues started rotting with growth of acervuli present over the entire surface of the hypocotyls. Pahogenecity involves by initial infections by massive production of appressoria containing spores all over the hypocotyl surface. Subsequently, hyphae grew inside the host tissues and destroyed the walls of underlying cortical cells. This was associated with extensive death of adjacent cells, which led to production of water-soaked lesions and finally it led to death of entire seedlings on severe infection (nectrotrophy).