Asian Research Journal of Current Science

This study was carried out to investigate the phenotypic reaction of 21 selected chilli accessions available in Sri Lanka for chilli anthracnose caused by mixed infection of Colletotrichum capsici and Colletotrichum gloeosporioides and protein level changes underlying with the plant response. A mixed inoculum of 10⁵ conidia ml^-1 of fungus was used and disease severity index (DSI) were calculated. A set of primers, designed based on resistant gene analogues (RGA) was used for PCR amplification of selected possible resistant gene sequences. Amino acid profiles were generated and were compared with similar amino acid profiles available in the NCBI. The results revealed that chilli accessions show varying degrees of susceptibility from low to high for anthracnose and none were resistant to anthracnose. The lowest DSI values reported from MI Hot (19.47), Hen miris (24.73), Galkiriyagama selection (26.74), C. baccatum (26.95) and MICH3 (27.03). The amino acid profiles showed that RGAs of chilli accessions, except MICH3 belonged to NB-ARC domain. Homology analysis on amino acid profiles showed a high diversity among the studied RGAs and varying susceptible reactions observed among 21 chilli accessions to the anthracnose disease caused by C. capcisi and C. gloeosporioides may be due to non-formation of required proteins as a result. MI Hot, Hen Miris, Galkiriyagama selection, C. baccatum and MICH3, which showed lower susceptibility to anthracnose disease, can be used in different combinations in breeding programmes to improve anthracnose resistance in chilli.  Molecular and protein level findings of this study may be useful in creating genetic resistance for anthracnose caused by C. capsici and C. gloeosporioides.