Inter- and Intra-Varietal Genetic Variability in Vitis vinifera

Grapevine (Vitis vinifera L.) is the most economically important and widely cultivated fruit crop in the world and its domestication produced cultivars suited to a wide diversity of climates and tastes In effect this genus shows a wide morphological and genetic variability that is causing confusions and ambiguity for biotypes and clones identification, in particular considering varieties that are widely distributed and cultivated for centuries. Ampelography, ampelometry, and biochemical traits analysis have been traditionally employed to identify the different biotypes in viticulture. However, these analyses are based on phenotypic characteristics which can be affected by environmental conditions The DNA molecular analyses are essential for internationally accepted grapevine identification and the investigation of genetic differences among the Vitis vinifera L. clones. Methods based on DNA analysis have been used with varying degrees of success. Simple sequence repeat (SSR) markers are universally used for the identification of the grape varieties. A molecular strategy to obtain DNA polymorphisms of Vitis vinifera genotypes from the same cultivar to study the intra- and inter- varietal genetic variability, to discriminate accessions, clones, and biotypes of a same grape variety, and to analyze the relationships between molecular profiles and some environmental parameters (i.e., geographic site) or morphological traits is described. This approach uses four different molecular marker systems (i.e., AFLP amplified fragment length polymorphism, SAMPL selective amplification of microsatellite polymorphic loci, M-AFLP microsatellites amplified fragment length polymorphism, and ISSR inter simple sequenced repeat).