Characterization of the complete chloroplast genome sequence of Gymnocoronis spilanthoides (Asteraceae, Eupatorieae) and its phylogenetic implications

Abstract

This study was the first report about complete chloroplast genome of Gymnocoronis spilanthoides (Asteraceae, Eupatorieae), a critically invasive plant. The circular whole cp genome of G. spilanthoides was 150,799 bp in length, contained a large single-copy (LSC) region of 82,514 bp and a small single-copy (SSC) region of 18,471 bp. These two regions were separated by a pair of inverted repeat regions (IRa and IRb), each of them 24,907 bp in length. A total of 135 functional genes were encoded, consisted of 89 protein-coding genes, 38 tRNA genes, and eight rRNA genes. The overall GC content of the chloroplast genome sequence was 37.5%, and the GC contents of the LSC, SSC, and IR regions were 35.6, 30.9, and 37.0%, respectively. The phylogenetic analysis by maximum likelihood showed that the G. spilanthoides was clustered into clade of Mikania and Ageratina by strong support values, and thus was closely related to members of Heliantheae and Inuleae. These results will be useful for the future studies of the naturalized and potentially invasive aquatic alien in the worldwide.