A new species and two new records of oomycetes causing downy mildew on Asteraceae in Brazil

Abstract

Abstract Species in the Asteraceae , either cultivated or wild, are strongly affected by downy mildews. Despite its importance, the broad species concept used for decades and the lack of molecular data for the genera Plasmopara and Bremia have obscured the true diversity and distribution of downy mildew-causing species in Asteraceae . Given the great relevance of downy mildew-causing oomycetes in Asteraceae , the objective of this study was to investigate the phylogenetic relationships of downy mildew-causing oomycetes in lettuce and other Asteraceae in Brazil. Based on molecular and morphological data, we describe a new species, Plasmopara pernambucoensis sp. nov., and present the first record of Plasmopara sphagneticolae in Brazil and South America, as well as the first record of Bremia sonchicola in Brazil.