Comparative genomics of Viola selkirkii and V. ulleungdoensis (Violaceae)

Chloroplast genomes of two morphologically similar species, Viola selkirkii and V. ulleungdoensis, were compared. For this comparison, three individuals of V. selkirkiii from Ulleung-do Island (UE), Jeju-do Island (JJ), and Hwacheon-gun (HC) and one of V. ulleungdoensis from UE were collected. According to chloroplast genome sequencing of V. selkirkiii and V. ulleungdoensis, their genomes were found to contain 156,774–157,454 and 157,575 bp, respectively, and a total of 111 genes. In the comparison of the three V. selkirkiii individuals, V. selkirkiii obtained in UE was distinguished from those of the other regions of HC and JJ, and in the comparison of the three V. selkirkiii individuals and one V. ulleungdoensis individual, V. selkirkiii obtained from UE and V. ulleungdoensis were distinguished from the species in the other regions. In addition, a phylogenetic analysis revealed that 32 taxa of Viola formed a monophyletic group (bootstrap support [BS] = 100). The four Viola individuals used in this study (three V. selkirkiii and one V. ulleungdoensis) formed a monophyletic group (BS = 100), which was further divided into two subclades. One subclade comprised V. selkirkiii found in UE and V. ulleungdoensis, whereas the other subclade comprised V. selkirkiii found in HC and JJ. These results support the view of prior studies that V. selkirkiii growing in UE and V. ulleungdoensis are the same species.