Distribution of Two Formae Speciales of Polymyxa graminis in the Czech Republic

It has been shown that two formae speciales of P. graminis, namely f. sp. temperata (ribotype Pg-I) and f. sp. tepida (ribotype Pg-II), are widely distributed throughout temperate areas of Europe. In this study, the presence of both forms of the temperate Polymyxa spp. was identified in soil samples from different locations of the Czech Republic during a survey performed in 2012 and 2013. Based on polymerase chain reaction results, of the total 58 tested samples, 67.2% contained at least one monitored forma specialis. Specifically, P. graminis f. sp. temperata was detected in 48.3% of soil samples, while P. graminis f. sp. tepida was detected in 44.8% of samples. Mixed populations were found in 25.9% of the tested areas. This plasmodiophorid was confirmed not only in crop fields but also in meadows and forests in all explored regions. Our results extend the knowledge on the distribution of both ribotypes of P. graminis and provide the first evidence of f. sp. tepida within the Czech Republic.