Gene pool variation and phylogenetic relationships of an indigenous northeast Italian grapevine collection revealed by nuclear and chloroplast SSRs.

A germplasm safeguard programme was set up with 19 grapevine varieties considered as indigenous to northeastern Italy. To better estimate how genetic structure can be used to obtain a conservation perspective of local varieties, genetic variability was examined at 30 nuclear and 3 chloroplast polymorphic microsatellite loci in the native varieties plus 7 European cultivars taken as reference. The genetic profiles of all the cultivars were searched for possible parentage relationships and several suspected cases of the same variety having different names were investigated. The alleles shared at the loci suggest a parent-offspring relationship between Merlot and Cabernet Franc, 'Gruaja' and 'Negrara Veronese', and Marzemina Nera and Marzemina Bianca. Alleles at the 30 nuclear loci are consistent with Raboso Veronese being the progeny of Marzemina Bianca and Raboso Piave. Chloroplast-specific haplotypes were singled out for the first time in this indigenous germplasm and should be considered typical of the region. It is hypothesized that there are many specific haplotypes for the local varieties due to a past contribution of wild grapevine to the cultivated gene pool. The majority of investigated cultivars were demonstrated to constitute an independent source of genetic variation, and therefore a possible valuable resource of genetic traits for breeders.