Common Names: chokecherry, common chokecherry, Virginia chokecherry
Researchers in Washington, USA, have identified two distinct species of powdery mildew affecting cherry crops. Phylogenetic analyses of the genetic and morphological features of the mildew confirmed that one mildew strain previously classified as Blumeria graminis is in fact a new species, designated Blumeria graminis var. prunus. The researchers also confirmed that the two species are host-specific, and unable to colonize one another. The work has important implications for cherry growers in the country, who will need to ensure they differentiate between the two mildews to effectively manage the disease and protect their crops. This study is also notable as it includes the first recorded European instance of the powdery mildew strain on cherry crops, along with its widespread occurrence in the US.