Abstract
Clubroot incited by Plasmodiophora brassicae Woron. causes serious yield losses in a wide range of brassica crops such as Chinese cabbage (Brassica rapa var. pekinensis). This pathogen is a root-invading organism belonging to the Plasmodiophorales, whose members are mostly obligate parasites. This pathogen does not grow in axenic culture, and can survives in soil as resting spores for a long period of time. These facts imply that the assessment of pathogenic activity of resting spores in soil is essential to study the ecology and control of the disease. The detection method using calcofluor white M2R and ethidium bromide has recently been developed. Other recent advances include in vitro growth of the pathogen and the inclusion of host-DNA in resting spores etc. A review of in vitro growth studies on Plasmodiophora brassicae was discussed here.
