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Ikegami, H.

Publications and source records attributed to Ikegami, H..

3 recordsLinked to original sources

Independent evolution of flavour and parthenocarpy in fig, one of the earliest domesticated fruit trees

Domestication often modifies multiple traits in concert, but whether fruit quality and reproductive mode share a genetic basis in perennial crops has not been tested at multi-omics resolution. In fig (Ficus carica), one of the earliest domesticated fruit trees and a crop with archaeobotanical evidence of cultivation over 11,000 years ago, domestication yielded both distinctive flavour and parthenocarpy, fruit development without pollination. We integrated whole-genome resequencing, transcriptomics, volatile and metabolite profiling, and taste sensor data across a diverse accession panel, using Bayesian GWAS/TWAS and multi-omics factor analysis. Flavour emerges as an integrated sensory system led by aroma, which modulates taste through cross-modal interactions, with sugar-acid balance as a secondary axis; these quality traits map to numerous independent loci. Parthenocarpy instead traces to a single perfectly concordant chromosome 04 haplotype (Eden) centred on FcMYB101-like, carrying a selective-sweep signature and a derived allele fixed in cultivated figs but rare across the genus. Flavour and reproductive mode thus evolved along separate genomic trajectories, allowing each to be improved independently.

plant biology↗

Propagation path of a flowering cherry (Cerasus x yedoensis) cultivar 'Somei-Yoshino' traced by somatic mutations

Flowering cherry cultivar Somei-Yoshino (Cerasus x yedoensis) has been clonally propagated and spread all around the world including Japan. Somei-Yoshino is thought to be an interspecific hybrid derived from C. spachiana and C. 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 of Cerasus species, 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.

plant biology↗

The Ficus erecta genome to identify the Ceratocystis canker resistance gene for breeding programs in common fig (F. carica)

Ficus erecta, a wild relative of common fig (F. carica), is a donor of Ceratocystis canker resistance in fig breeding programs. Interspecific hybridization followed by recurrent backcrossing is an effective method to transfer the resistance trait from wild to cultivated fig; however, this is time consuming and labor-intensive for trees, especially for gynodioecious plants such as fig. In this study, genome resources were developed for F. erecta to facilitate fig breeding programs. The genome sequence of F. erecta was determined using single-molecule real-time sequencing technology. The resultant assembly spanned 331.6 Mb with 538 contigs and an N50 length of 1.9 Mb, from which 51,806 high-confidence genes were predicted. Pseudomolecule sequences corresponding to the chromosomes of F. erecta were established with a genetic map based on single nucleotide polymorphisms from double-digest restriction-site associated DNA sequencing. Subsequent linkage analysis and whole genome resequencing identified a candidate gene for the Ceratocystis canker resistance trait. Genome-wide genotyping analysis enabled selection of female lines that possessed resistance and effective elimination of donor genome from progeny. The genome resources provided in this study will accelerate and enhance disease resistance breeding programs in fig.

genomics↗