2024 Volume 33 Pages 154-161
Scutellaria kikai-insularis is a small perennial herb in Lamiaceae, endemic to Kikai Island in the Amami Islands, Kagoshima, Japan. Recently, wild populations have declined due to the land development, and this species was listed as a designated national endangered species under the Act on the Conservation of Endangered Species of Wild Fauna and Flora in Japan. Owing to the clonal nature of the species, the exact number of clones/genets remains unknown, which poses a major problem for its conservation. In this study, we conducted population genetic analysis using genome-wide SNPs to understand the population and genetic status of the remaining populations. We sampled 140 ramets from the entire population previously recorded on the island and subjected to genetic analysis. In total, 59 clones were identified, reflecting the high clonality of the species. Additionally, larger patches tended to be dominated by a single clone. Genetic diversity was lower than that of closely related species, but there was no evidence of inbreeding due to cleistogamous self-pollination. Based on these results, it was suggested that small patches occurring in many clones should be preferentially protected to maintain clonal diversity. Also, the movement of clones between patches within the conservation units proposed in this study is desirable to facilitate sexual reproduction.
