Resumen de Development of molecular markers for powdery mildew resistance in grapevines
Siraprapa Mahanil, A. J. Garris, C. M. Owens, D. Ramming, Lance E. Cadle-Davidson
Molecular markers linked to disease resistance can be used to pyramid resistance genes for improved durability and to improve the efficiency of evaluation. To develop molecular markers linked to resistance to grape powdery mildew (Erysiphe necator), Vitis romanetii was used to create a pseudo-backcross 2 mapping population by crossing C87-41 ((V. romanetii × V. vinifera) × V. vinifera) with B70-57 (V. vinifera). Resistance was assessed in multiple locations and years by both natural and artificial inoculation. A genetic map was constructed using 101 SSRs and 28 SNPlex markers. This source of disease resistance is qualitative, fits a single-resistance gene model, and was mapped to the Ren4 locus on chromosome 18. Two markers, VMC7f2 and SNPlexE1M4R1 were shown to be tightly linked to powdery mildew resistance and seedlessness. Together they will be a valuable tool for marker assisted selection in table grape breeding programs.
