Identification of Pathogen-Specific Novel Sources of Genetic Resistance Against Ascochyta Blight and Identification of Their Underlying Genetic Control.

Global chickpea production is restricted by Ascochyta blight caused by the necrotrophic fungi . Developing locally adapted disease-resistant cultivars is an economically and environmentally sustainable approach to combat this disease. However, the lack of genetic variability in cultivated chickpeas and breeder-friendly markers poses a significant challenge to Ascochyta blight-resistant breeding efforts in chickpeas. In this study, we screened the mini-core germplasm of against a local pathotype of . A modified mini-dome screening approach resulted in the identification of five accessions showing a high level of resistance. The mean disease score of resistant accessions ranged between 1.75 ± 0.3 and 2.88 ± 0.4 compared to susceptible accessions, where the mean disease score ranged between 3.59 ± 0.62 and 8.86 ± 0.14. Genome-wide association study revealed a strong association on chromosome , explaining ∼58% of the phenotypic variance. The underlying region contained two candidate genes ( and ), the characterization of which showed the presence of a DNA-binding domain (cl28899 and cd18793) in and its orthologs in , whereas carried an additional N-terminal domain (cl31759). qPCR expression analysis in resistant and susceptible accessions revealed ∼3- and ∼110-fold higher transcript abundance for and , respectively.