Enzymatic and biochemical aspects of anthracnose resistance in chili (Capsicum annuum L.) genotypes

Chili (Capsicum annuum L.) genotypes and hybrids resistant to anthracnose disease are not yet commercially available, and under favorable environmental conditions, the crop suffers significant yield and economic losses. In this study, six chili genotypes and 15 hybrids were screened for their resistance to anthracnose disease. Various plant disease resistance-related parameters were assessed, and the genotypes Bidhan Chili 4, Chinese Bona, and Pant C 1, along with the hybrids Pant C 1 × Bidhan Chili 4, Bidhan Chili 4 × Chili 38-Ragi, and Chinese Bona × Chili 38-Ragi, exhibited resistance to anthracnose disease. To gain a deeper understanding of chili defense mechanisms, biochemical changes in key defense enzymes—such as polyphenol oxidase (PPO), peroxidase (POX), and phenylalanine ammonia-lyase (PAL)—as well as protein and phenol content in fruits (both before and after inoculation) were analyzed. The results showed that resistant genotypes and hybrids exhibited higher activity levels of PPO, POX, and PAL, along with increased protein and phenol content, compared to susceptible ones. These elevated biochemical responses in Colletotrichum capsici-inoculated fruits suggest that these mechanisms play a crucial role in enhancing host resistance against anthracnose disease.