Zonate Leaf Spot of Prunus mandshurica Caused by Hinomyces pruni in Korea

Zonate leaf spots and severe defoliation were observed on Manchurian apricot (Prunus mandshurica) growing in a humid location in Korea from 2011 through 2013. The main symptoms included greyish green to brownish grey and zonate leaf spots without border lines, which mostly led to premature defoliation. The morphological characteristics of the causal agent were consistent with Hinomyces pruni. Identification was supported by analysing the sequence of the internal transcribed spacer region of ribosomal DNA from an isolate. The pathogenicity of the isolate was confirmed by artificial inoculation. This is the first report of zonate leaf spot caused by H.pruni on Manchurian apricot globally as well as in Korea.