Identification of Sources of Resistance in a Collection of Wild Germplasm.

is an important fungal pathogen of chickpea ( L.), and it can cause yield losses up to 100%. The wild progenitors are much more diverse than domesticated chickpea, and this study describes how this relates to resistance. Initially, the pathogenicity of nine Australian isolates was examined on three lines to develop a robust phenotyping assay, and significant differences in isolate aggressiveness were identified with six isolates being classed as highly aggressive and three as moderately aggressive. We identified two isolates, CU8.20 and CU10.12, to be highly aggressive and moderately aggressive, respectively. A subsequent phenotyping assay was conducted using the two isolates to evaluate 86 wild accessions ( and ) and two varieties for resistance to . A subset of 12 genotypes was further evaluated, and subsequently, two wild accessions with consistently high levels of resistance to were examined using the initially characterized nine isolates. Wild accessions Karab_084 and Deste_063 demonstrated consistent partial resistance to . There were significant differences in responses to across wild collection sites. The Cermik, Karabahce, and Destek sites' responses to the aggressive isolate CU8.20 ranged from resistant to susceptible, highlighting an interaction between isolate genotype and chickpea collection site for sclerotinia stem rot resistance. This is the first evidence of partial stem resistance identified in wild germplasm, which can be adopted in chickpea breeding programs to enhance resistance in future chickpea varieties.