Genetic map construction in an apple cross: Efficiency of an automatic sequencer to generate genetic markers with high throughput

Apple scab, caused by the fungal pathogen Venturia inaequalis, is one of the most important disease of apple trees. Many sources of resistance have been described, most of them are under the control of major dominant genes. There are also apple selections that contain resistances not yet well investigated, such as polygenic resistance from particular selections of the Russian cultivar 'Antonovka'. A 'Golden Delicious' x 'Freedom' population was created; progenies segregate for both the V-f and polygenic resistances and an apple linkage map using AFLP and SSR markers was developed in order to identify markers tightly linked to the polygenic character. A total of 716 molecular markers, 648 from 50 AFLP primers combinations and 51 SSRs, were used for the two parental maps constructed with JoinMap (R) v 3.0. The position of SSR loci was consistent with other linkage maps in Malus. The map presented here is a starting point for a detailed and integrated map. The use of the capillary electrophoresis for SSR and AFLP analyses and the software package for data collection offers a great improvement in fragment scoring and data handling. It is also a simple and fast approach toward creating transferable maps and for the generation of markers with high throughput.