Assessment of Genetic Fidelity in Regenerants from Two Vitis vinifera Cultivars

Genetic stability of regenerants is a fundamental feature when somatic embryogenesis is used for regeneration after genetic transformation as well as for germplasm cryopreservation and for virus eradication. On the contrary, somatic embryogenesis has been used in breeding strategies based on the exploitation of somaclonal variations. In order to assess the genetic fidelity of regenerants and the possibility of off-type somaclones, we applied molecular typing on a number of anther and ovary-derived grapes. Plantlets were obtained by indirect somatic embryogenesis from anthers and ovaries of 'Grignolino' and 'Dolcetto' (Vitis vinifera L.). Thirty-seven lines of 'Grignolino' and nine of 'Dolcetto' were evaluated through SSR analysis using 20 nuclear microsatellite loci for 'Grignolino' and nine for 'Dolcetto'. All checked samples generated the same SSR profile of the cultivar and clone of the original explant. AFLP assays were also performed on 14 lines of 'Grignolino' using two primer combinations for selective amplification. None of AFLP bands produced showed polymorphism among the lines. In addition, an experimental vineyard was planted in spring 2005 with plants from the same lines. No major difference between regenerants and control plants was observed so far. Further analyses are in progress.