First report of hop stunt Viroid infecting strawberry in China.
Strawberry (Fragaria ananassa) is an important economic fruit that is widely grown in China. Hop stunt viroid (HSVd) is a member of the genus Hostuviroid (family Pospiviroidae) and was first described from hops with stunt disease in Japan. This viroid affects grapevine, peach, sweet cherry, apricot, cucumber, and almond, causing serious diseases, such as chlorotic and yellowing symptoms of leaves. So far, there was no report about HSVd infection on strawberry in China. In the autumn of 2016 and 2017, severe shrinking and chlorotic and yellowing symptoms resembling viroid infections were observed on strawberry plants in Linyi and Weifang, Shandong Province. Samples were collected from 10 plants exhibiting yellowing and 10 symptomless plants. Based on the results of PCR-based assay and pathogenicity test, the causal agent was identified as HSVd. This is thought to be the first report of HSVd affecting strawberry plants in China.