S01 - Session P5 - New breeding technology approaches to improve apple and pear varieties

Authors: Stefano Tartarini, Cecilia Domenichini, Paola Negri, Luca Dondini *, Sara Alessandri, Lorenzo Bergonzoni, Ignazio Verde, Mickael Malnoy

Genome editing and cisgenesis are powerful new breeding techniques (NBTs) for designing precise genome modifications, particularly in crops presenting a long juvenile phase and high heterozygosity, like fruit trees. Apple ( Malus x domestica ) and pear ( Pyrus spp.) are two important pome fruit crops worldwide, but, in recent years, several challenges, such as unfavourable conditions during flowering, pathogen attacks and extreme weather events produced significant yield losses. Accordingly, various NBT approaches have been started in apple and pear with the aim to obtain improved varieties for some of these traits. To date, two fire blight resistance genes have been isolayed from wild apples. However, the recent characterisation of Malus / Pyrus hybrids assisted in the transfer of apple resistance genes to pear by cisgenesis. In addition, the availability of apple fire blight susceptibility genes (i.e. DIPMs) makes it possible to knock them out by CRISPR/Cas9 gene editing. Finally, to improve pear production, self-compatible pear genotypes are being developed through DNA editing. The first results of these experiments will be presented.