The complete chloroplast genome of a critically endangered tree species in China, Cyclobalanopsis obovatifolia (Fagaceae)

Abstract

Cyclobalanopsis obovatifolia: (Fagaceae) is a critically endangered plant species, of which only six populations have been recorded. In this study, we characterized the complete chloroplast genome of C. obovatifolia based on next generation sequencing (NGS), which is the first chloroplast genome that have been reported in Cyclobalanopsis species. The circular complete chloroplast genome of C. obovatifolia was 160,817 bp in length, containing a large single-copy (LSC) region of 90,210 bp and a small single-copy (SSC) region of 18,989 bp. These two regions were separated by a pair of inverted repeat regions (IRa and IRb), each of 25,809 bp. A total of 134 functional genes were encoded, consisted of 86 protein-coding genes (79 PCG species), 40 tRNA genes (33 tRNA species), and eight rRNA genes (4 rRNA species). The overall GC content of the chloroplast genome was 38.1%, whereas the corresponding values of the LSC, SSC, and IR regions were 34.8, 31.1, and 42.8%, respectively. The maximum likelihood (ML) phylogenetic analysis showed that C. obovatifolia and Quercus edithiae were clustered into one clade with strong support values, indicating their closer relationship.