Screening And Identification Of Resistant Sources Against Sclerotinia Sclerotiorum Causing White Mold Disease In Common Bean

White mold caused by Sclerotinia sclerotiorum (Lib.) de Bary is a devastating constraint in common bean (Phaseolus vulgaris L.) production, affecting plants at both seedling and adult stages. Being a crop of small-area, resource-poor, farmers and given the high cost of fungicides, farmers prefer the use of region-specific landraces or resistant accessions. In this study, we compared various methods of bean plant inoculation with S. sclerotiorum and found modified straw test method of inoculation as most accurate and effective. Using this method, we screened a panel of 516 common bean germplasm procured from 22 countries through the National Bureau of Plant Genetic Resources (NBPGR; New Delhi, India) against white mold pathogen. Only 12 accessions were found resistant, whereas 121 were moderately resistant to white mold. Among exotic resistant accessions, EC271515, EC271475, EC271523, and EC271528 were from the Colombian region, while the remaining four, EC530910, EC530913, EC530916, and EC531044, belonged to Columbia. Of the four resistant landraces from India, IC280353 was a collection from Jammu and Kashmir State, whereas landraces IC278744, IC278709, and IC278734 were from Himachal Pradesh. Considering the area under disease progress curve (AUDPC), incubation period, infection rate, and lesion length, EC-271475 followed by EC-530916 were concluded to be the best accessions against white mold. Further, the statistical analysis also confirms the highly resistant nature of phenotypically screened common bean accessions. One exotic accession, EC271475, possessing resistance to S. sclerotiorum was also resistant to bean common mosaic virus (BCMV) strain NL-7n and could be used in common bean breeding programs.