Targeted Gene Editing in Pome Fruit Genetics and Breeding: State-of-the-Art, Application Potential and Perspectives

Even though traditional breeding of perennial fruit trees such as apple and pear has resulted in high performing cultivars in the past, it is a very lengthy and costly process that is unable to keep up with the increasing demands for improved yield, resistance and fruit quality posed by the growing world population and the rapidly changing climate. In the last decade, significant research advances have been made that can revolutionize pome fruit breeding to meet current needs, including the sequencing of apple and pear genomes, the increased understanding of associations between gene(s) and traits of interest, and the advancement in genetic engineering tools. In particular the emergence of genome-editing tools such as the CRISPR/Cas9 technology can significantly improve the speed and accuracy of pome fruit breeding programs. This chapter reviews the progress, opportunities and challenges of genome editing tools in apple and pear, and discusses the genetic basis of several important breeding goals to find possible targets for new gene-editing applications.