Early detection of white mold caused by Sclerotinia sclerotiorum in potato fields using real-time PCR

Potato white mold caused by Sclerotinia sclerotiorum is an important plant disease occurring in many potato-producing areas worldwide. This disease causes considerable yield losses in a large number of potato fields of Hamedan province, Iran. Although several non-chemical methods have been suggested against the pathogen, application of chemicals is considered a major method employed by the growers in Hamedan fields leading to considerable pollution of underground water. Therefore, it is necessary to find techniques to help growers make a more timely decision for chemical application. In this research, a pair of PCR primers was designed according to the nucleotide sequence of a region of DNA amplified by the primer M13. This primer set amplified a 352-bp fragment from all isolates of S. sclerotiorum collected from Hamedan, Iran, and Hangzhou, China. However, this situation was not observed in other tested fungi. A real-time PCR assay was conducted to detect early infection of the pathogen on potato petals. This real-time PCR assay is suggested for growers to make timely decisions on chemical application.