Molecular identification of bean genotypes for partial resistance to Sclerotinia sclerotiorum based on SCAR markers

White mold caused by the fungal pathogen Sclerotinia sclerotiorum (Lib.) de Bary is a devastating disease reducing bean seed yields qualitatively and quantitatively worldwide. Overall, it is one of the most difficult diseases to control. Host resistance is the best strategy to reduce risks of epidemics. In this study, Sequence Characterized Amplified Region (SCAR) markers were applied to identify bean genotypes possessing the resistance gene and conferring resistance to white mold. Polymerase chain reaction (PCR) was performed using two pairs of SCAR SS18 and SF13R10 primers to amplify specific fragments in bean genotypes with partial resistance 1650 and 410 base pair respectively. Our results showed that two pairs of SS18 and SF13R10 primers were tested on 46 genotypes but the expected bands were amplified in 21 bean genotypes. Additionally, we validated this result via infection assay performed under glasshouse conditions. Disease severity evaluated eight days post-inoculation (dpi) through a 1–9 scale in such a way scale 1 and 9 represented as no sign of disease and total plant collapse, respectively. The obtained results revealed that Cranberry bean had the least sensitivity. The two genotypes of white beans, Great Northern and White Kidney had the highest sensitivity to S. sclerotiorum and had lowest levels of resistance in bean.