A new badnavirus in Ribes species, its detection by PCR, and its close association with gooseberry vein banding disease

Gooseberry vein banding disease (GVBD) affects Ribes species and cultivars worldwide. It is the second most important virus-like disease in these crop s after black currant reversion disease. In this paper, we describe a bacil liform virus, Gooseberry vein banding associated virus (GVBAV), which is as sociated closely with GVBD, and provide evidence that GVBAV is a distinct s pecies within the genus Badnavirus. Purified GVBAV particles were ca. 120 x 30 nm in size and contained dsDNA. The sequence of a 1.5-kb DNA fragment a mplified from viral genomic DNA was similar to those of a wide range of bad naviruses and contained motifs characteristic of the RNase H domain of the badnavirus open reading frame (ORF) III polyprotein. Phylogenetic analyses suggest that GVBAV is most closely related to Spiraea yellow leaf spot viru s. Using sequence derived from the polymerase chain reaction (PCR)-amplifie d DNA fragment, virus-specific primers were designed. These primers were us ed in PCR to assay for GVBAV in a range of Ribes germplasm affected with GV BD, with other unrelated virus-like diseases and viruses found in Ribes, an d in healthy plants. GVBAV was detected in all of 58 GVBD-affected plants f rom diverse sources, but not from healthy Ribes plants nor from plants infe cted with other viruses.