Unravelling the novel source of resistance and differential reactions on chilli die back and fruit rot through screening of various chilli genotypes

Dieback and fruit rot, caused by Colletotrichum species, are significant pre- and post-harvest
diseases affecting chili (Capsicum spp.), with C. capsici being the most prevalent species in
India. A study evaluating the resistance of 41 capsicum genotypes to these diseases revealed
varying levels of resistance. While some moderately cultivated lines and crosses showed
resistance, genotypes such as Bhut Jolokia, PBC-380, and IC-383072 remained symptomless.In vivo, inoculation trials with C. capsici determined that nine days post-
inoculation is the optimal time for assessing disease resistance. These screenings identified
nine highly resistant and eleven highly susceptible genotypes. Consistently resistant
genotypes to dieback included BS-35, BS-20, BS-28, Punjab Lal, Bhut Jolokia, Taiwan-2, IC-
383072, and Pant C-1. Additionally, BS-28, CC-0189, and Hisar Sakti demonstrated
immunity to fruit rot. Further analysis of genotypes inoculated with C. capsici isolates
revealed the presence of two distinct pathotypes. Eleven genotypes, including Bhut Jolokia,
BS-27, BS-28, BS-35, BS-37, CC-0189, Hisar Sakti, IC-326272, and IC-383072, exhibited
resistance to fruit rot. Challenges of this study were genetic variability among genotypes,
environmental factors, selection pressure, lack of clear biomarkers, pest & disease
complexes, limited availability of resistant genotypes. These findings contribute in
encapturing of resistant genotypes against fruit rot and dieback and succeed. and emphasize
the importance of detailed studies on the prevalent pathogen strains in specific regions to
enhance resistance breeding efforts. The newly identified resistant genotypes serve as
valuable resources for advancing breeding programs targeting dieback and fruit rot resistance.