Sabino Kikuchi Izai A B, Keßler Paul J A, Schuiteman André, Murata Jin, Ohi-Toma Tetsuo, Yukawa Tomohisa, Tsukaya Hirokazu
Universiteit Leiden, Hortus botanicus Leiden, PO Box 9500, Leiden, 2300 RA, The Netherlands.
Science Directorate, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK.
PhytoKeys. 2020 Feb 19;140:11-22. doi: 10.3897/phytokeys.140.46842. eCollection 2020.
The orchid tribe Tropidieae comprises three genera, , and . There are three fully mycoheterotrophic species within Tropidieae: , and . A previous phylogenetic study of , based only on plastid data, placed outside the clade of and without support. In this study, we performed phylogenetic analyses using a nuclear ribosomal DNA spacer (ITS1-5.8S-ITS2), a low-copy nuclear coding gene () and a mitochondrial intron ( intron) to study the phylogenetic relationships within Tropidieae. We included six photosynthetic and all three fully mycoheterotrophic Tropidieae species. The resulting phylogenetic trees placed these fully mycoheterotrophic species inside the clade with high support. In our trees, these three species do not form a monophyletic group together, because the photosynthetic is nested amongst them. Our results also suggest that the loss of photosynthetic ability occurred at least twice in .
地宝兰族（Tropidieae）包括三个属，即地宝兰属（Geodorum）、斑叶地宝兰属（Dienia）和曲唇地宝兰属（Cochleanthes）。地宝兰族中有三个完全菌异养的物种：圆叶地宝兰（Geodorum rotundatum）、落地金钱（Dienia biflora）和台湾曲唇兰（Cochleanthes formosana）。先前一项仅基于叶绿体数据对圆叶地宝兰（Geodorum rotundatum）进行的系统发育研究，将其置于地宝兰属（Geodorum）和斑叶地宝兰属（Dienia）的分支之外，且缺乏支持。在本研究中，我们使用核糖体DNA间隔区（ITS1 - 5.8S - ITS2）、一个低拷贝核编码基因（MADS）和一个线粒体内含子（matR内含子）进行系统发育分析，以研究地宝兰族内部的系统发育关系。我们纳入了六个光合物种以及所有三个完全菌异养的地宝兰族物种。所得的系统发育树将这些完全菌异养的物种置于地宝兰属（Geodorum）分支内，且支持度很高。在我们构建的树中，这三个物种并未共同形成一个单系类群，因为光合物种台湾曲唇兰（Cochleanthes formosana）嵌套在它们之中。我们的结果还表明，光合能力的丧失在地宝兰属（Geodorum）中至少发生了两次。
