Plasmodiophora brassicae in Mexico: From Anecdote to Fact

For years, the presence of clubroot disease and its causal agent, Plasmodiophora brassicae, in Mexico has been stated as a fact. However, an intensive search of the scientific literature in English and Spanish, as well as grey literature including thesis and government reports, did not reveal any information about the actual detection of the pathogen, affected hosts, or areas with clubroot presence, or any information about clubroot (‘hernia de la col’, in Mexico). To confirm if P. brassicae was indeed in Mexico, we started a true detective adventure. First, we identified agricultural communities with a history of cruciferous crop cultivation. Secondly, we interviewed growers if they did see clubroot on their crops using pictures of the characteristic root galls. Thirdly, we collected soil from the locations with reported presence of clubroot and looked for the presence of clubroot/P. brassicae in the soil using several cruciferous bait plants. For the very first time we confirm the presence of the clubroot pathogen P. brassicae in Mexico, through a bioassay, the presence of resting spores and a P. brassicae specific PCR assay. The identification of P. brassicae in Mexico, will contribute to understand the genetic diversity of this elusive and devastating plant pathogen in future studies.