Molecular Detection and Pathogenicity Assay of Plasmodiophora brassicae in Chicken Manure

To determine the relationship between animal excreta and the occurrence of clubroot disease of cruciferous crops caused by Plasmodiophora brassicae, chickens were fed with resting spores of the pathogen. Their faeces were collected and used to inoculate crucifers. This study proved that both fresh and composted manures could induce clubroot and the presence of the pathogen in the manure was confirmed by PCR amplification. However, composting had detrimental effects on the virulence of the resting spores in the manure. When the temperature was over 32°C, the incidence and severity of clubroot declined with the increase in the exposure time of resting spores to high temperature and the pathogenicity was completely lost when the spores were kept at 48°C for 6 h. The control measures for the clubroot disease were discussed.