Confirmation of Peronospora agrimoniae as a distinct species

Peronosporaceae Species Causing Downy Mildew Diseases of Poaceae, Including Nomenclature Revisions and Diagnostic Resources

“…from checklist publications ( Farr & Rossman 2021 ) need further investigation. Given that most Peronosporaceae species are highly specialized and their taxonomy follows a narrow species concept ( e.g ., García-Blázquez et al 2008 , Thines & Choi 2016 , Petrželová et al 2017 ), it seems unlikely that these hosts from three different plant genera with different photosynthetic pathways are parasitized by Sclerospora farlowii . There are also several smuts that parasitize Deyeuxia species that could potentially be mistaken for the resting spores of a sclerospora-like species ( Vánky & Guo 2001 ), as was the case when Sclerospora graminicola was mistakenly brought into connection with the smut species Ustilago urbani ( Waterhouse 1964 , Shaw 1975 ).…”

“…data). Broadly speaking, since most Peronosporaceae species are specialized to parasitism of a single or only a few host species, records of this species as a broad-host range pathogen of 13 different genera across two plant families are inconsistent with expectations for the species ( e.g ., Thines & Choi 2016 , Petrželová et al 2017 ). More specifically, most – but not all – experimental evidence from host range studies points to the distinction between Sclerospora graminicola strains that infect pearl millet from those that infect Setaria spp., including foxtail millet ( Melhus et al 1928 , Safeeulla 1976 , Francis & Williams 1983 , Singh et al .…”

“…As with all organisms capable of inciting plant diseases, reliable and accurate identification of the GDM pathogens is crucial, but identification is only possible when the characters that can be used to identify them are clearly known. Any taxonomic or nomenclatural confusion that would lead to the misidentification of species or misapplication of a name could hinder efforts to identify introduced species, detect emerging pathogen threats, and track the spread of disease ( Thines & Choi 2016 , Petrželová et al . 2017 , Davis & Crouch 2022a ).…”