Minority grape varieties: varieties in danger of extinction?
In general, a minority variety is considered to be one that is cultivated very little, compared to the rest of the varieties, in a certain region.
Some varieties have been decreasing their cultivated area while others have increased , thanks to agronomic characteristics that are beneficial for the viticulturist: large bunches, high yields, high price per weight, low attack by pests and diseases, easy handling of the crop, etc.
The programs of clonal selection promote genetic erosion of those varieties which are not studied. Generally, the most cultivated ones are selected, to the detriment of those that are less widely.
If the definition is taken rigorously, we could say that many of the varieties grown in Spain should be considered a minority. However, a series of aspects must be taken into account:
- There may be varieties that, although cultivated in a small area in a certain region, exist predominantly in other Spanish regions or even outside of Spain, and that therefore should not be included within the minority ones. In the Canary Islands, the Airén variety is grown under the name Burrablanca , which, due to its scarce cultivation area on the islands, could be mistakenly considered a minority.
- There are varieties of scarce cultivation that their belonging to a Denomination of Origin only allows their use and does not guarantee a sufficient degree of protection against their extinction, so specific measures are necessary for their conservation.
- Attention must be paid to those varieties that are grown marginally and that are not covered under any DO and in some cases are not included in the Register of Commercial Varieties of Spain, and therefore present special vulnerability.
Given the importance of the conservation of minority varieties, work should be done on their recovery through complete studies of morphological, molecular and agronomic characterization, identification and evaluation of the oenological potential.
The first step to recover the minority varieties of vine is to get in touch with those winegrowers who have, from their point of view, unknown or unique vineyards, and who have been planted for more than 60 years. The age of the plant guarantees that it is not of recent introduction.
At the beginning of summer, when the plant is in full vegetative development, its visual examination is carried out , where it will be discerned if the plant is interesting to be recovered.Of those plants marked as interesting, samples are collected to carry out DNA analysis , which, by studying their genetic profile, will allow us to determine if the plant is synonymous with another known one or not.
From the plants from which samples were obtained whose genetic profile was different or that show some morphological character of peculiar visu, withered shoots are taken that will later be rooted in pots , which will be arranged in a shade so that, once the plant has sprouted, be protected from the sun and the wind.
The morphological study will be carried out in situ, on the original plots.
The following year, the plants rooted in pots are transplanted to the field where they can grow without space limitation. From the third year on , new phenological and morphological studies will be carried out to confirm that the expression levels of each trait are maintained after the plant duplication.
It is considered that the knowledge and protection of the minority grape varieties is essential to guarantee the rich varietal heritage of Spain , both from the point of view of genetic conservation, as well as its contribution to the typicality of the wines.