S01 - Session O5 - I - Routine development of marker-assisted breeding (MAB) on apple and pear and new approaches for QTLs and major gene genotyping involved in disease resistance

Authors: Aurélien Petiteau *, Caroline Denance, Charles-Eric Durel, Hélène Muranty, François Lebreton, Bernard Petit, François Laurens

Apple and pear breeding is a long process that can take more than 20 years. Considering the future challenges of fruit growing (maintaining high and regular yields in a changing environment), it is essential to improve the efficiency of breeding programs. The development of marker-assisted breeding (MAB) based on SNP markers is a way to reach this goal. Several tools, such as the Illumina 20K array and the Affymetrix-Axiom 480K (apple-fruit) and 70K (pear) arrays, have been developed to map SNP markers to the respective genomes. However, practical use of markers by breeders are still disconnected from academic knowledge. To overcome this gap, we tested several SNP-based methods in apple and pear, and validated some of them in our programs after having evaluated their benefits and limitations, with the final goal to use them in our commercial breeding programs. To do so, we both tested and validated published markers associated with major genes and developed new markers linked to QTLs involved in disease resistance. The set of validated markers is now routinely used in our breeding programs. In this paper, after discussing the methodology of SNP genotyping, we will present the difficulties encountered in the search for new markers associated with major genes and QTLs. We will then present the solutions considered and the associated results.