Apple Breeding and Postharvest in the Post-Genomic Era

With the release of the apple genome and the current availability of affordable next generation sequencing technologies, plant breeding and fruit postharvest entered into a new era. Genomic information, together with the development of new sophisticated phenotyping devices, allowed the identification of valuable markers suitable for an assisted selection of relevant complex traits for apple, such as fruit texture. Different strategies have been employed for the marker identification, from association studies to translational comparison with model species, such as tomato.  In addition to this, once these features are selected from the ongoing breeding programs, an important aspect that need to be considered is represented by their dynamics throughout the postharvest storage. In this context, a genome wide transcriptomic survey was performed to elucidate the functional machinery controlling the physiological modification occurring during the postharvest fruit ripening as well as the development of superficial scald, one of the most severe disorders in apple. This repertoire of information have been subsequently exploited to identify a subset of candidate genes suitable for the functional characterization of the fruit maturity and ripening behavior, especially with regards to 1-MCP, an ethylene competitor largely used to extend shelf-life and to prevent severe fruit quality decay. Both genetic and functional markers would permit, in the end, a more efficient and advanced selection of the most valuable new apple accessions, allowing also to step forward in the understanding of different physiological aspects related to fruit quality.