Isolation and variation in virulence of single-spore isolates of Plasmodiophora brassicae from Canada.

摘要: Xue, S., Cao, T., Howard, R. J., Hwang, S. F., and Strelkov, E. 2008. Isolation variation in virulence of single-spore isolates Plasmodiophora brassicae from Canada. Plant Dis. 92:456462. Clubroot crucifers, caused by brassicae, is emerging as an important disease canola (Brassica napus) Alberta, Populations the pathogen often consist a mixture different pathotypes. Therefore, simple efficient method to isolate single resting spores P. was developed, based on serial dilution spore suspensions. The 24 isolates, representing five populations Ontario, British Columbia, characterized differentials Williams Some et al. Symptoms were rated 6 weeks after inoculation Fisher’s least significant difference (P < 0.05) used differentiate resistant susceptible host reactions. pathotype composition Canada appeared more diverse when examined rather than pathogen. In at three possibly four pathotypes identified among 14 tested, whereas maximum only two had been reported previously examined. Pathotype 3 or P2, classified al., respectively, found be predominant province. occurrence other lower frequencies suggests that caution should any breeding strategy, because rare may quickly become if genotypes are continuously grown.