Propagation path of a flowering cherry (Cerasus×yedoensis) cultivar ‘Somei-Yoshino’ traced by somatic mutations

Abstract

AbstractFlowering cherry cultivar ‘Somei-Yoshino’ (Cerasus×yedoensis) has been clonally propagated and spread all around the world including Japan. ‘Somei-Yoshino’ is thought to be an interspecific hybrid derived fromC. spachianaandC. speciosa; however, its origin is unclear. Since somatic mutations are randomly induced in genomes and stably transmitted through generations, we aimed to identify somatic mutations in the genome of ‘Somei-Yoshino’ to trace its propagation path. A total of 46 ‘Somei-Yoshino’ clones were collected from all over Japan and subjected to whole-genome sequencing. The results revealed 684 single nucleotide variants, of which 71 were found in more than two clones. Clustering analysis of the 46 clones using these 71 variants revealed six groups, four of which contained 40 of the 46 clones. In addition, because each of the four clones closely planted in Ueno Park, Tokyo, Japan, clustered into the four different groups, we considered that these four clones could be the ancestors of the ‘Somei-Yoshino’ clones found in Japan. Furthermore, based on the comparison of mutant alleles with the genomes ofCerasusspecies, one of the four trees was concluded as the closest to the origin. Here, we propose that the origin of ‘Somei-Yoshino’ is a chimera derived from at least four somatic mutants.