Analysis of a spontaneous mutant and selected clones of cv. Italia (Vitis vinifera) by AFLP markers

A spontaneously formed mutant and selected clones (from clonal selection) of the table grape cv. Italia (Vitis vinifera) were evaluated with regard to the the possible use of molecular markers for grapevine clone differentiation. The identified off-type grapevine, which presents a mutated branch and a normal one on the same plant, removes any doubt as to its origin and allows a better evaluation of the suitability of molecular markers for the differentiation of grape clones. AFLPs were used as molecular markers because a large number of loci can be screened in a single assay, which is useful for any study on genotype relationships when a large number of bands (variables) is required. Different primer combinations (49) produced 3880 scorable AFLP bands but none showed any polymorphism among clones. Nevertheless it is suggested to use both AFLP and morphological markers for the differentiation of grapevine clones. The AFLPs would confirm the high level of DNA similarity among the suspected clones while morphological characters would allow to verify, through appropriate field experimental designs, the reliability of the phenotypic differences detected among grape clones.