Multiplex TaqMan qPCR Assay for Detection, Identification, and Quantification of Three Species.

White mold (or Sclerotinia stem rot), caused by species, is a major air, soil, or seed-transmitted disease affecting numerous crops and wild plants. Microscopic or culture-based methods currently available for their detection and identification are time-consuming, laborious, and often erroneous. Therefore, we developed a multiplex quantitative PCR (qPCR) assay for the discrimination, detection, and quantification of DNA collected from each of the three economically relevant species, namely, , , and . TaqMan primer/probe combinations specific for each species were designed based on the gene sequences encoding aspartyl protease. High specificity and sensitivity of each probe were confirmed for sclerotium and soil samples, as well as pure cultures, using simplex and multiplex qPCRs. This multiplex assay could be helpful in detecting and quantifying specific species of , and therefore, may be valuable for disease diagnosis, forecasting, and management.