Elimination of grapevine virus A (GVA) by cryopreservation of in vitro-grown shoot tips of Vitis vinifera L

Abstract

Methods for the cryopreservation of in vitro-grown shoot tips of grapevine were recently developed [1,2]. The present study demonstrates that grapevine virus A (GVA) can be successfully eliminated from naturally infected grapevine by cryopreservation of in vitro-grown shoot tips. The various steps taken before freezing in liquid nitrogen did not, by themselves, eliminate GVA. However, the freezing step resulted in 97% GVA elimination. The size of the shoot tips used for cryopreservation influenced their survival rate, while viral eradication was independent of their size in the range of 0.5–2.0 mm. In comparison, plant regeneration from meristems increased with size, and meristems of 0.1 mm completely failed to regenerate. Regeneration from 0.4-mm meristems reached 100%, but none of the regenerated plantlets were GVA-free. Meristems of 0.2 mm resulted in only 12% GVA-free plants. Frequency of GVA elimination was not affected by the cryopreservation procedure, be it encapsulation–dehydration or vitrification. Leaf morphology of plants regenerated from cryopreserved shoot tips was similar to that from control shoot tips. Results from the present study suggest cryopreservation of shoot tips as a simple and efficient method for eliminating GVA from infected grapevine plants.