Reticulate Evolution in Japanese Sceptridium, including diploid, tetraploid, and hexaploid species (Ophioglossaceae).

This study demonstrated that the Japanese Sceptridium hexaploid is an allopolyploid with a hybrid origin, having a maternal ancestor that is a related species or an ancestor of the tetraploid Japanese S. formosanum, and having a paternal ancestor that is a related species or a common ancestor of the diploid S. nipponicum, S. triangulare, and S. microphyllum. Furthermore, it concluded that the narrow-leaved individuals observed in Japan likely have certain traits fixed due to high self-fertilization, as no genetic differentiation was observed with S. atrovirens. These data were used in phylogenetic and clustering analyses and were obtained through Sanger sequencing and MIG-seq analysis.本研究证实，日本产六倍体阴地蕨属（Sceptridium）物种为异源多倍体，起源于杂交事件；其母本祖先为近缘物种，或是四倍体日本台湾阴地蕨（S. formosanum）的祖先类群，父本祖先则为近缘物种，或是二倍体日本阴地蕨（S. nipponicum）、三角叶阴地蕨（S. triangulare）与小叶阴地蕨（S. microphyllum）的共同祖先。此外，本研究得出结论：日本境内观测到的狭叶个体大概率因高自交率而固定了特定性状，因未观测到其与暗绿阴地蕨（S. atrovirens）存在遗传分化。本研究数据通过桑格测序（Sanger sequencing）与MIG-seq分析（MIG-seq analysis）获得，并应用于系统发育分析与聚类分析。