Evaluation of Anthracnose Resistance in Pepper (Capsicum spp.) Genetic Resources

Anthracnose (Colletotrichum spp.), is one of the major yield losing fungal disease in both pre- and post-harvest stage of pepper (Capsicum spp.) production worldwide. Among the Colletotrichum spp., C. acutatum has strong pathogenicity, which infects both immature and mature pepper fruit leads to severe economic losses in pepper production. Inheritance of anthracnose disease resistance was evaluated with 3738 pepper genetic resources which was collected from different countries and conserved at Korean genebank. The resistance analysis against pepper anthracnose (C. acutatum) was performed on detached mature green and red fruits under laboratory conditions by spray (non-wounding) and microinjection (wounding) inoculation methods. In the primary screening, about 261 accessions were appeared to be resistant against C. acutatum in spray inoculation. The resistant accessions were further evaluated with microinjection (wounding) inoculation method using the fungal (C. acutatum) isolate of pepper anthracnose. There were highly significant differences in the disease severity and distribution of disease rating scale, considering all the sources has significant genetic variation. Finally, the anthracnose resistant pepper accessions have been validated with cleaved amplified polymorphic sequence (CAPS) and high-resolution melting (HRM) markers in which, the CAPS and HRM marker analysis showed four types of genotypes such as resistant (R), susceptible (S), heterozygous (H) and Unidentified type (UT) or not detection. The Capsicum accessions showing high level of resistance to the pathogen could be used as source material in breeding programs for resistance to anthracnose disease.

Automated summary

Anthracnose, caused by Colletotrichum spp., is a major fungal disease affecting pepper production globally. Evaluation of resistance in 3738 pepper genetic resources identified potential sources of resistance to C. acutatum, with further validation using molecular markers for breeding programs.