The complete chloroplast genome of Korean <i>Pyrus ussuriensis</i> Maxim. (<i>Rosaceae</i>): providing genetic background of two types of <i>P. ussuriensis</i>

Abstract

Pyrus ussuriensis Maxim. is one of the most important pear species cultivated in Asia, grown in northern China, far-east Russia, Korea, and Japan. Here we completed the chloroplast genome of wild P. ussuriensis collected in Bonghwa-gun, Korea, which was 159,986 bp in length consisting of four subregions: 87,947 bp of large single copy (LSC) and 19,255 bp of small single copy (SSC) regions are separated by 26,392 bp of inverted repeat (IR) regions. The genome contained a total of 130 genes including 85 protein-coding genes, eight rRNAs, and 37 tRNAs. The overall GC content was 36.5% and those in the LSC, SSC, and IR regions were 34.2%, 30.4%, and 42.6%, respectively. Phylogenetic analysis of 14 Pyrus chloroplast genomes provided the diverse genetic background for wild P. ussuriensis populations in Korea by confirming that wild P. ussuriensis sequenced in this study contained Pyrus pyrifolia type plastome. It revealed substantial sequence variations up to 121 single nucleotide polymorphisms and 781 insertions and deletions against another wild accession of P. ussuriensis (P. ussuriensis type) collected in Mt. Hambaek, Korea.