Proceedings of the XLVII Italian Society of Agricultural Genetics - SIGA Annual Congress

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Poster Abstract - 2.23

ISOLATION OF NEW APPLE CULTIVARS WITH MARKER ASSITED SELECTION (MAS)

S. PASSEROTTI, M. KOMJANC, P. MAGNAGO, E. ZINI, C. TOLLER, P. BALDI, L. ZULINI, I. PERTOT

Istituto Agrario di San Michele all’Adige, via E. Mach 1, 38010 San Michele all’Adige (TN), Italy

apple, Marker Assisted Selection, apple scab

Since 1990 the Agricultural Institute of San Michele all’Adige (TN)-Italy has been involved in genetic researches on apple. In that year programs of classical genetic breeding and molecular studies started in order to obtain cultivars resistant to apple scab and to study genes involved in the interaction with the fungal pathogen Venturia inaequalis (apple scab). In 2000 a new project, “Advanced Biology Applied to Grape, Apple and Salmons” financed by the CARITRO foundation., started.

Apple breeding at Agricultural Institute of San Michele all’Adige is aimed at combining high fruit quality with good orchard and conservability performance and pyramiding durable disease resistance for a sustainable production. To select new cultivars with a major defence capacity against the pathogen population is necessary pyramiding different resistance gene in one single genotype. In particular polygenic resistance and major resistance genes should be combined.

Marker Assisted Selection (MAS) is supposed to be extremely useful in the process of pyramiding resistance genes against the same or different pathogens. It is also possible to pyramide major genes and polygenes, called quantitative trait loci (QTL). Actually there are different molecular markers associated to resistance genes which are produced from different European research groups.

At present, at Agricultural Institute of San Michele all’Adige, 49 different crossings have been considered and about 2800 samples collected. In this crosses it was introgressed: Vf, Vm, Vbj, Va (monogenic), Vb for scab resistance and Pl1, Pl2 for powdery–mildew resistance. Of this 49 crosses: 25 were for Vf, 11 for Vf+Pl1, 7 for Vf+Pl2, 1 for Vf+Va, 1 for Vf+Vbj, 1 for Vf+Vb, 1 for Vf+Vm, 1 for Vm and 1 for Vbj. The molecular markers used in Marker Assisted Selection (MAS) were: AL07 and M18 for Vf, CH05e03 for Vbj, Vm for Vm, AT20 for Pl1 and N18 for Pl2.

The MAS aim was not only to pyramide genes but also to single out homozygote plants for Vf and plants with recombination effects in the Vf region.