Identification of virus free clones of the winegrape varieties and rootstocks required in Australia to enable the establishment of elite nuclear source collections for vine improvement schemes

Abstract

Identification of virus free clones of the winegrape varieties and rootstocks required in Australia to enable the establishment of elite nuclear source collections for vine improvement schemes

Summary

It is crucial that disease free planting material is used when establishing a vineyard. Many vineyards in Australia have vines with virus infections due to the use of infected planting material. Leafroll viruses are the most detrimental of these. They cause yield losses which vary from minor to more than 50% and affect grape quality by delaying maturity and reducing fruit colour in red varieties. Rugose wood viruses can affect vine vigour and yield and cause incompatibility and death of grafted vines.

There are a number of genetic resource collections of grapevines in Australia – the largest of these are held by CSIRO and SARDI. However, when this project began, there were no nuclear collections. These are collections of clones certified free of important viruses, which are established as source material for vine improvement schemes. This project was seen as the first step in the establishment of such collections – the sanitary selection of clones. Candidate clones in the project were selected from the main genetic resource collections in Australia.

Preliminary screening of these clones for viruses was undertaken using laboratory RT-PCR and ELISA methods. The remaining clones have then been further screened using biological indexing. This involves grafting them to indicators, growing them for several years in a field planting and observing them for virus symptoms. The Australian Vine Improvement Association has established a national nuclear collection of 200 of the clones selected in the project at the NSW DPI Research Station at Dareton. In the Wine Australia submission SAR 03/05 to continue this project, funding was also requested for the indexing of an additional 60 clones.

Funding is still required for this additional indexing to complete the collection at Dareton. The clones selected in the project will be made available under a licence agreement to any vine improvement group in Australia wishing to distribute them. As part of this project a catalogue is being finalised which contains more detailed information on the nuclear clones. This catalogue will be set up on the SARDI website in 2005 and it will be of particular value in publicising the clones. The feasibility and cost of integrating an updated national register of clones with the catalogue on the website is being investigated.