Elimination of viruses from three grapevine rootstock cultivars and certification using RT-PCR and next-generation sequencing

Abstract

In Japan, cultivars ‘Kober 5BB’ (Vitis berlandieri × Vitis riparia), ‘Riparia Gloire’ (V. riparia), and ‘101-14’ (V. riparia × Vitis rupestris) are used as rootstocks for table or wine grapes. As newly emerging viruses were detected from some mother rootstocks, elimination of viruses from the three cultivars was performed using thermotherapy and meristem culture. Among sixteen to eighteen clones obtained, we selected six clones each in the first screening by reverse-transcription polymerase chain reaction (RT-PCR). Mixed RNA extracts from the six were analyzed by next-generation sequencing. No viruses were detected from all the clones, although some of them tested positive for viroids. Consequently, no viruses and viroids were detected from two to six clones of all the cultivars. The clones will be utilized as rootstocks for virus-free vines in Japan.