Loquat is a new natural host of apple stem grooving virus and apple chlorotic leaf spot virus in China.
Loquat (Eriobotrya japonica) is an evergreen tree species in the family Rosaceae. It is native to the cooler mountain regions of China to south-central China and cultivated in Asia and Europe for its fruit and as an ornamental. Leaves and fruits of loquats have traditionally been considered to have high medicinal value. In March 2018, a leaf curl symptom was observed on loquat trees in an orchard in Chongqing, China. A literature search did not reveal any reports describing viral pathogens infecting loquats, although several bacterial and fungal diseases have been documented. To investigate the etiology of the symptoms, total RNA was extracted using EASYspin Plus Complex Plant RNA Kit (Aidlab Biotech) from the leaves of one symptomatic loquat tree. Results of sequence analysis, direct tissue blot immunoassay assay, reverse transcription PCR revealed two causal agents, i.e. Apple stem grooving virus (ASGV) and Apple chlorotic leaf spot virus (ACLSV), the members of the genus Capillovirus and Trichovirus, respectively. This is thought to be the first report of natural infection of viral pathogens in loquats, showing the expanding host range of the viruses.