Applying new breeding technologies to horticultural crops

The interest in new breeding technologies is constantly growing in the plant biotechnology world. Cisgenesis and genome editing joined to “omics technologies” offer invaluable opportunities to identify, introduce or disrupt specific genes in the plant genome in shorter timescales when compared to traditional approaches such as as breeding or traditional GMOs. While the application of these new technologies in model plant and herbaceous crops underwent great and rapid development in the last years, in fruit trees only few studies are published at the moment. Many challenges in fact still hamper the gene transfer techniques in grapevine and apple resulting in a low efficiency of the process even in the presence of a selectable marker gene. In this presentation we describe two different approaches we are experiencing in our labs: (i) in order to obtain cisgenic fruit crops, we have developed methods based on site-specific recombination for the removal of the selectable marker genes. After the selection phase, it appeared more feasible and effective if compared to approaches that avoid their use and rely the discrimination of transformed event on demanding and labour intensive screening analysis. (ii) Experiments are progressing to apply the CRISPR system in grapevine and apple for the inactivation of genes with a key role in susceptibility to diseases like apple and grape powdery mildew and apple fire blight. Methods relying on a binary vector carrying the specific sgRNA and Cas9 delivered into plant cell via Agrobacterium tumefaciens but exploiting the effectiveness of constructs which allow the removal of Cas9/sgRNA expression cassette are under investigation.