Quantification of Plasmodiophora brassicae Resting Spores in Soils Using Droplet Digital PCR (ddPCR)

• DOI: 10.1094/pdis-03-19-0584-re
• Publication Date: 2019-11-27T13:55:48Z
• Authors: Rui Wen; Jillian Lee; Mingguang Chu; Nazmoon Tonu; Tim Dumonceaux; Bruce D. Gossen; Fengqun Yu; Gary Peng
• Keywords: Clubroot; Potting soil

Plasmodiophora brassicae, an obligate soilborne pathogen that causes clubroot on Brassica crops, is spreading rapidly in western Canada, threatening canola production the region. Bioassays and molecular assays have been used to estimate concentration of P. brassicae resting spores soil, which can affect incidence severity crops. Droplet digital PCR (ddPCR) a promising new approach for quantification inoculum owing its low sensitivity inhibitors consistency at target concentrations. The objective this study was assess ddPCR against existing quantitative (qPCR) potential advantage and/or improvement quantifying soil. protocol enumerated accurately spiked potting mix or soil samples ranging from 10 2 7 per gram. At spore ≥10 gram, however, became less accurate, with tendency overestimation. validated by brown, dark black soils using both qPCR simultaneously. These types are found commonly Canadian Prairies, they vary texture, pH, organic content. showed similar results among different types, whereas often displayed lower counts same concentration, amplification DNA inhibited completely samples. inhibition be removed 10-fold dilution show more versatile tool than detection