Akademik Veri Yönetim Sistemi
9th International Conference on Grape Genetics and Breeding, Udine, İtalya, 31 Mayıs 2009, cilt.827, ss.535-538
Segregation of quantitative resistance to powdery (Uncinula necator) and downy (Plasmopara viticola) mildew was followed to investigate responsible QTLs in three different Vitis mapping populations. The first results from a cross of 'Regent' (resistant) x 'Lemberger' (susceptible), the second from 'Gf. Ga. 47-42' (a resistant breeding line) x 'Villard blanc' (resistant), and the third from the cross of breeding line 'V3125' (susceptible) to 'Borner' (resistant). The progenies comprised between 141 and 188 individuals and were genotyped using predominantly microsatellite-derived molecular markers to construct framework maps. Some resistance gene analogues were also included (Welter et al., 2009). The resulting linkage/recombination maps are easily comparable to each other and to international reference maps (Riaz et al., 2004; Adam-Blondon et al., 2004). Phenotypic data obtained through field scoring of resistance on leaves and berries through four to five years were combined with genotypic information to investigate significant QTL regions in two of the three crosses. Concerning P. viticola resistance, three minor and one major QTL region were identified on four linkage groups in 'Regent', while only one major QTL located on a different linkage group was identified for U. necator resistance. Quite in contrast, results from the cross of 'Gf. Ga. 47-42' x 'Villard blanc' indicated only one major QTL region carrying factors directed against both U. necator and P. viticola operating in leaves and fruits. This region corresponds to the major QTL for downy mildew resistance of 'Regent' identified on linkage group 18.