Assessment of Colletotrichum Capsici and C. Gloeosporioides Resistance among Chilli Accessions Available in Sri Lanka

Abstract

Anthracnose is one of the most destructive fungal diseases in chilli (Capsicum annuum L.), which affects the seed production and post-harvest quality of the product. There are no reports available on the resistance levels of chilli varieties to anthracnose caused by Colletotrichum spp. in Sri Lanka. Therefore, the present investigation was carried out to find sources of resistant for anthracnose in locally available chilli accessions. One isolate from each, C. capsici and C. gloeosporioides species were selected for the study. Ripened chilli pods of twenty-one chilli accessions were screened against both Colletotrichum spp. (droplet of spore suspension-105 spores/ml) separately under in-vitro conditions (28 ̊C-temperature, 100%-RH) during Maha 2016/17 with three replicates. The results showed that the disease reaction of C. capsici and C. gloeosporioides isolates on different chilli accessions were not significantly different from each other (p>0.23). However, a significant difference (p < 0.0001) in Disease Severity Index (DSI) for anthracnose among chilli accessions was observed for both isolates. The highest DSI value of 79.47 for both C. capsici and C. gloeosporioides isolates, respectively. DSIs of Jaffna Purple for both Colletotrichum spp. were significantly different from the DSIs of the other accessions. The lowest DSI values were observed in MI Hot (19.47 and 19.47), Hen miris (24.73 and 24.73) and Galkiriyagama selection (23.21 and 27.03) for C. capsici and C. gloeosporioides, respectively; which, also grouped together. According to the results, MI Hot, Galkiriyagama selection and Hen miris showing lower DSI values can become sources for developing anthracnose resistant/ tolerant chilli lines.