First report of branch cankers caused by Sphaerulina musiva on Populus purdomii in the United States.
In November 2017 numerous branch cankers were observed on a specimen of Populus purdomii in a cultivated plant collection in Boone County, Kentucky, USA. Branch cankers were abundant on small to medium-sized branches. Cankers displayed sunken and discoloured tissue with swollen margins and were causing dieback in the canopy. The causal pathogen was isolated and identified as Sphaerulina musiva based on morphological, molecular and pathgenicity analyses. The obtained sequence was deposited in the GenBank (accession no. MH379707). This is thought to be the first report of S. musiva causing branch cankers on P. purdomii in the USA.