Plant & Animal Genome VI Conference

P282

IDENTIFICATION OF MARKERS LINKED TO THE SEEDLESSNESS CHARACTER IN GRAPEVINE

1. UR-GAP Viticulture, INRA-ENSAM, 2, place P. Viala, 34060 Montpellier - France
2. INRA, Station d'Amélioration de la Pomme de terre et des Plantes à Bulbe, Domaine de Kéraiber, 29260 Ploudaniel - France

In order to improve the selection of new table grape cultivars, we have initiated a marker assisted selection program for seedlessness. According to Bouquet and Danglot (1996), this trait might be controlled by three complementary recessive genes regulated by a dominant gene named sdI (for seed development Inhibitor). Bulk segregant analysis (Michelmore et al. 1991) was used to search for random amplified polymorphic DNA (RAPD) markers linked to the sdI gene in a progeny obtained by crossing two partially seedless genotypes. One hundred and forty decamer primers were screened using bulks obtained by pooling the DNA of extreme individuals from the phenotypic distribution. We identified two RAPD markers which appeared tightly linked to sdI (0.7 and 3.5 cM respectively). The closest marker was used to develop a codominant SCAR (sequence characterized amplified region, Paran and Michelmore 1993), named SCC8. This latter marker appeared of great value to exclude from the progeny undoubtedly seeded individuals or to select undoubtedly seedless individuals. Indeed, all the seeded individuals of the progeny were found homozygous scc8-/scc8- and all the individuals homozygous SCC8+/SCC8+ were seedless. Moreover, SCC8 was also interesting to dissect more precisely the genetic of seedlessness. ANOVA analysis indicated that this SCAR marker accounted for at least 64.9% of the phenotypic variation of the seeds fresh weight and for at least 78.7% of the phenotypic variation of the seeds dry matter.