A research project launched in Austria in 1993/94 by ARC Seibersdorf (Austria Research Center ULB Umwelt-, Lebenswissenschaften- und Biotechnologie) and VitroPlan GmbH aims to significantly improve the quality of Austrian wines by gradually planting certified vines (the first phase was completed in 2001). The background is provided by several EU Directives, the implementation of which led to the "Austrian Rebverkehrsgesetz 1995". The aim is to ensure that in the future the planting material will meet defined quality criteria, and above all that it is free of defined diseases. Many vines show latent infections, which are further spread during vegetative propagation and grafting.
These diseases sometimes only affect quality and yield after many years and shorten the life span and yield. These include above all viruses and bacteria, which can cause many vine diseases, for example wood diseases (see Rugose Wood-Complex). 200 clones of the most important Austrian grape varieties were collected, tested for viruses and bacterioses using various methods and subjected to a thermal process to remove viruses. All conspicuous clones were eliminated. About 40 clones of 25 grape varieties (i.e. 30%) met the health criteria and could be included in a priority list.
The selection was carried out by a panel of experts and representatives of Austrian viticulture. There is a certain weightiness of white wine. The latest trends regarding the increasing importance of red wine varieties were not yet fully visible at the time of selection of the clones, an extension in this direction would be desirable. Actually, more than 300 clones were tested, but not all of them went through the full programme. However, a potential of 25 to 30 further clones can be drawn upon, on which the tests have been completed and which meet the required criteria of plant health. However, these have not (yet) been taken into account when drawing up the priority list.
The different clones per grape variety are each a variety and can play an important role in the flavour of a variety-typical bouquet and in the optimal adaptation to local conditions. In France, special emphasis is placed on the preservation of clone diversity, where important varieties are represented by over 300 clones. The preservation and future propagation of important varieties should always be based on several clones. The implementation of the EU Directive on the certification of plant material means that in 30 to 40 years' time there will only be certified vineyards in Austria; possibly at the expense of the autochthonously developed clone diversity. See also under vine enemies.
