A Narrow Endemic or a Species Showing Disjunct Distribution? Studies on Meehania montis-koyae Ohwi (Lamiaceae)

Abstract

Meehania montis-koyae Ohwi (Lamiaceae), which has been considered a narrow endemic and endangered species in Japan, was found in eastern China in 2011. China and Japan belong to the same floristic region and share many plant species, but it is very rare that Japanese narrow endemic species are newly found outside of the country. We examined herbarium specimens of both countries, and conducted analyses of molecular phylogenetics, population genetics, and divergence time estimation using two nuclear (ITS and ETS) gene regions and MIG-seq data. Chinese plants tend to become larger than Japanese, and they are different in leaf shape and floral features. Molecular phylogenetic analysis shows Chinese and Japanese M. montis-koyae are the closest relatives to each other. Population genetic analysis indicates no current gene flow between the Chinese and Japanese populations, and divergence time analysis shows they were separated during the late Miocene. We reach the conclusion that Chinese and Japanese M. montis-koyae have already become distinct biological entities, and a new taxon name Meehania zheminensis A. Takano, Pan Li, G.-H.Xia is proposed for the Chinese plants. A key to Asian Meehania species is provided.

Nuclear and plastid phylogenomic analyses provide insights into the reticulate evolution, species delimitation, and biogeography of the Sino‐Japanese disjunctive Diabelia (Caprifoliaceae)

“…Our results show that that the interchanges of the populations of D. spathulata between Korea and Japan are frequent. The close relationships between Japan and Korea have also been observed in other taxa such as Meehania urticifolia (Miquel) Makino (Takano et al, 2020) and Kirengeshoma koreana Nakai (Qiu et al, 2011). Furthermore, our results also suggest that populations of D. spathulata in Korea originated from Japan and are likely due to recent vicariance and dispersal events (Fig.…”

Nuclear and plastid phylogenomic analyses provide insights into the reticulate evolution, species delimitation and biogeography of the Sino-Japanese disjunctive Diabelia (Caprifoliaceae)

“…Our results show that that the interchanges of the populations of D. spathulata between Korea and Japan are frequent. The close relationships between Japan and Korea have also been observed in other taxa such as Meehania urticifolia (Takano et al, 2020) and Kirengeshoma koreana (Qiu et a1., 2011). Furthermore, our results also suggest that populations of D. spathulata in Korea originated from Japan and are likely due to recent vicariance and dispersal events (Fig.…”

“…1; Hara, 1983). Although there have been several previous studies on the discontinuous distribution between China and Japan (Lu et al, 2020; Haq et al, 2020; Takano et al, 2020), groups showing a higher distribution in Japan than China are rarely involved. Prior work on Diabelia focusing on the intermittent distribution in China and Japan is lacking.…”

“…This intermediate form may be the result of hybridization. There have been several previous studies on the disjunctive distributions between China and Japan (e.g., Lu et al, 2020; Haq et al, 2020; Takano et al, 2020), with most studies focusing on species that are widely distributed in Japan. The disjunctive distribution of Diabelia dates back to the middle Oligocene, covering the long geological history of the formation of flora in China and Japan (Yang et al, 2011; Shin et al, 2012; Zhao et al, 2019; Wang et al, 2020).…”

“…There have been several previous studies on disjunct distributions between China and Japan (e.g., Lu et al, 2020;Haq et al, 2020;Takano et al, 2020), with most studies focusing on species that are widely distributed in Japan. Disjunct distribution patterns typically have been attributed to vicariance or long-distance dispersal events (Doyle et al, 2004;Baenfer et al, 2006;Bobo-Pinilla et al, 2018;Torres-Cambas et al, 2019;Wang et al, 2020;Nge et al, 2021).…”