ChileanJAR

Until recently grape cultivars were identified based entirely on ampelographic criteria. Currently a number of molecular techniques based on PCR can be applied for exhaustive genetic analysis on plants. These methods proceed through the direct analysis of DNA, in this way avoiding the interference due to environmental interactions. In this paper the application of RAPD and AFLP for the analysis of genetic diversity in a group of more than 50 grape cultivars is presented. Using 18 RAPD primers, 103 information bands were identified, corresponding to 29.9% of polymorphism. In comparison, using only four AFLP primers produced 86 information bands, with a very similar percentage of polymorphism (29.6%). Both methodologies exhibited an adequate degree of reproducibility, evaluated on a collection of 48 Cabernet Sauvignon clones. The dendrograms based on these data sets graphically depicted the ability of both methods to differentiate all the cultivars studied. In the case of Cabernet Sauvignon clones, AFLP permitted the identification of a number of differences that could be related to morphological differences detected among these clones, such as cluster length. The comparison of both methods, principally related to their ability to differentiate cultivars and clones, suggests that AFLP is the more adequate method for both purposes. Nevertheless, both methods could be implemented, given that under controlled conditions appropriate levels of polymorphism and reproducibility are displayed.