5William s P H. A system for the determination of races of Plasmodiophora brassicae that infect cabbage and rutabaga[J]. Phytopathlagy, 1966, 56: 624-626.
6Howard R J. Strelkov S E. Harding M W. Clubroot of erucif- erous crops-new perspectives on an old disease [J]. Canadian Journal of Plant Pathology, 2010,32 ( 1 ) : 43 - 57.
7Johnston T D. Club root in Brassica: A standard inoculation technique and the specification of races 2J:. Plant Pathology, 1968,17(4): 184 - 187.