Clonal selection of cv. 'Aleatico' along Tuscan coastal area.

The results of the grapevine clonal selection carried out in Tuscany in the last seven years not only provided evidence of a high concentration of viral infections, but also showed that the sanitary status of the variety Aleatico is extremely worrying. The sanitary tests conducted on 172 plants, selected in the Elba Isle, on the hills around Lucca and in Maremma region showed a critical phytovirological condition. In fact, only 5 plants passed the first sanitary screening, being found free of all viruses investigated (GFLV, ArMV, GFkV, GLRaV-1, GLRaV-3, GLRaV-7, GVA and GVB). The candidate clones selected in Maremma showed remarkable differences in their morphological traits, both from one another ('ALESCA 59' and 'ALESCA 60' on one side, and 'ALCHI 1 on the other), and from those that had been identified on the Elba Isle ('ALE 102' and 'ALE 119'). The differences found among the 3 biotypes were statistically confirmed by cluster analysis procedures concerning the OIV traits of the shoots, leaves and bunches, and through the results of preliminary DNA analyses conducted in 6 micro-satellite loci. The general analysis of the available data showed the following decreasing scale of virus spreading values for the variety Aleatico (for the studied viruses): GLRaV-3>GLRaV-l>GVA>GFLV>GFkV. ArMV, GLRaV-7 and GVB have never been found. Differences in the infectious combinations ascertained in the 3 areas of selection are particularly interesting. The presence of mixed infections did not affect the vines that had been selected in the Maremma region and only slightly affected those from the Lucca hills, while 16 different combinations were found for the Elba Isle. The worrying sanitary status of Aleatico and the lack of registered clones of this variety seem to attach great importance to the results of this work, even if still quantitatively poor, for the improvement of the island's vine-growing activity along with the promotion of Aleatico wine, whose excellent organoleptic features and uniqueness are well-known. ©2006 IEEE