SOMATIC VARIATION IN GRAPEVINE

¹ Departamento de Genética Molecular de Plantas. Centro Nacional de Biotecnología, CSIC. Campus de la Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.

² Departamento de Mejora Genética y Biotecnología, SGIT, INIA. Ctra. de la Coruña Km 7, 28049 Madrid, Spain.

³ Centro de Investigación y Desarrollo Agroalimentario, 30150 La Alberca (Murcia), Spain

Grapevine breeding is tightly regulated in some European countries with a long tradition in wine production - e.g. Spain, France, Italy - in order to maintain the typical character of their wines. Since classic wine varieties of Vitis vinifera are propagated vegetatively, the only varietal improvement allowed is clonal selection based on the identification of somatic variants differing from the mother plant on agronomic traits. When differences have an incidence on morphological characters (e.g. hairiness) or wine properties (e.g. colour), the clone is considered a new variety. Stable clone-specific markers can help to identify the most genetically divergent clones thereby strengthening clonal selection efforts. The same tools can be use to certify and protect the selected clones of interest. The aim of this work was to analyze somatic variation in Spanish grapes. With this purpose we have identified polymorphisms among branches of centenary grapevines belonging to different classical Spanish wine grapevine varieties using multiplex DNA fingerprinting techniques (e.g. AFLP and SAMPL). In the case of the Garnacha variety, we have analyzed three branches of nine clones. Ninety-seven of the 2072 total bands were polymorphic. Two different classes of polymorphisms were identified: (i) 57 fragments detected in some branches of different clones (likely indicating hot spots of recombination), and (ii) 40 fragments identified in a single branch of one of the clones (labeling single event polymorphisms). The analysis of these polymorphic bands will contribute to obtain quantitative information on the origin and stability of somatic variation in the variety. Comparative analysis between varieties is an interesting source of information on genotypic effects in the rate of accumulation of somatic variation.