The use of resting spore spheroplasts in the DNA analysis of Plasmodiophora brassicae

Plasmodiophora brassicae (Woronin) is a soil-borne fungus causing the clubroot disease on the crucifers. In spite of the great cost to agriculture imposed by this disease, very little is known about the molecular genetics of P. brassicae. We have been engaged in a series of studies to elucidate the ultrastructure of the resting spore wall of P. brassicae. Recently we have developed a method for preparation of spheroplasts from the resting spores by using some enzymes. Here we describe some aspects of the genomic and the chromosome-size DNA prepared from the spheroplasts.