Blackcurrant reversion virus: Validation of an improved diagnostic test, accelerating testing in breeding and certification of blackcurrants

Abstract

A study was commenced in 2005 to provide a validated diagnostic test for the detection of Blackcurrant reversion virus (BRV) to be used as an alternative to the conventional test recommended for use in the UK certification scheme. A range of cultivars previously virus indexed and held as nuclear stock (Baldwin, Ben Lomond and Ben Tirran) were grafted with known BRV-positive scions and assessed over the following four years. Data was collected through visual observations and buds sampled and tested with a single round RT-PCR using two new primer sets. For the method to be accepted for use in Scotland the detection rate must be equal or better than that of the existing grafting method. Statistical analysis of our results for the detection of both the European (E) and Russian (R) forms of Reversion disease in the three cultivars provides a validation for this test. We suggest that this method provides a faster throughput test for BRV even when no symptoms are visible on the plants, and so is suitable for adoption into the guidelines followed by both UK and European authorities for detection of BRV in blackcurrant propagation material.