Detection of Prunus necrotic ringspot virus and Prune dwarf virus in sweet cherry (Prunus avium) and Chinese cherry (Prunus pseudocerasus) in Shandong Province, China

To investigate the occurrence of Prunus necrotic ringspot virus (PNRSV) and Prune dwarf virus (PDV) in sweet cherry orchards in China, a total of 57 leaf samples including 51 from sweet cherry (Prunus avium) and 6 from Chinese cherry trees (Prunus pseudocerasus) displaying virus disease-like symptoms were collected from 10 orchards in Shandong Province, the major sweet cherry production area in China. Total RNA was extracted by a CTAB-based method. As a result of the RT-PCR tests, PNRSV and PDV were detected in 34 (59.6%) and 27 (47.4%) of 57 samples, respectively. Twenty-two of the samples were infected by both viruses simultaneously and caused more serious symptoms, including plant structural dwarfing, shortened internodes and fruit blast. Although our survey was limited to Shandong Province, the results may reflect the status of Chinese sweet cherry in general, as this region is the main stone fruit and seedling production area. To our knowledge, this is the first extensive investigation of commercial sweet cherry orchards for Ilarvirus species in China.