QTLs for fertility in table grape (Vitis vinifera L.)

Fertility (number of inflorescences per shoot) is a trait of major importance for grapevine breeding. We present and compare the results of quantitative trait locus (QTL) detection for fertility in two table grape progenies, MTP3140 and MTP3234. Novel parental and consensus maps were built for MTP3140. We found a main QTL on linkage group (LG) 5 in both progenies, which was also the most stable one across years. It explained up to 18.5% of the total intra-cross phenotypic variance. Three other QTLs, one on LG 5 and two on LG 14, were repeated over years but were found in a single progeny. Our results suggest that QTLs effect was mainly additive. The prospects for testing candidate genes are discussed as well as the potential interest of these results for marker-assisted selection.