THE PEACH GENOME: INSIGHTS ON GENETIC DIVERSITY AND DOMESTICATION

Abstract

Rosaceae is the most important fruit producing clade and its key commercially relevant genera (Fragaria, Rosa, Rubus, Prunus) display a broad diversity in growth form and fruit type, as well as compact diploid genomes. Peach is one of the best genetically characterized deciduous trees. Here, we provide a concise review of the salient features of the peach whole genome sequence and highlight specific aspects of its genome organization. A complete chromosome-scale assembly was obtained by Sanger whole genome shotgun methods. We predicted 27,852 protein-coding genes as well as non-coding RNAs. Analyses of the expansion of gene families related to sorbitol metabolism and to the phenylpropanoid network highlighted cornerstone features in the evolution of the Spiraeoideae subfamily and a Prunus-specific mode of genome evolution likely associated with unique production of the lignified stone in these species. Moreover, we investigated the path of peach domestication through whole genome resequencing of 14 Prunus accessions. The analyses suggest major genetic bottlenecks that have significantly shaped peach genome diversity. Furthermore, comparative analyses show that peach has not undergone a recent whole genome duplication (WGD) and even though the ancestral triplicated blocks in peach are fragmentary compared to those in grape, all seven paleosets of paralogues from the putative paleoancestor are detectable.