AUTHOR=Zhou Yun , Zhang Yu-Qu , Xing Xiao-Cheng , Zhang Jian-Qiang , Ren Yi 

TITLE=Straight From the Plastome: Molecular Phylogeny and Morphological Evolution of Fargesia (Bambusoideae: Poaceae)

JOURNAL=Frontiers in Plant Science

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00981

DOI=10.3389/fpls.2019.00981

ISSN=1664-462X

ABSTRACT=<p><italic>Fargesia</italic> is ecologically and economically important in mountainous forests. Many <italic>Fargesia</italic> species are also important sources of food for some endangered animals such as the giant panda. Recent molecular phylogenetic analyses have revealed <italic>Fargesia</italic> as a polyphyletic group despite some unclear lineage affinities. In the present study, we reconstructed the phylogeny of <italic>Fargesia</italic> and its allies, including <italic>Thamnocalamus, Arundinaria</italic> (incl. <italic>Bashania</italic>), <italic>Yushania, Indocalamus, Ampelocalamus</italic> and <italic>Phyllostachys</italic>, from a plastome sequence matrix that contained 20 <italic>Fargesia</italic> and five <italic>Yushania</italic> species as ingroups, 16 species from nine other bamboo genera plus <italic>Oryza sativa</italic> and <italic>Zea mays</italic> as outgroups. <italic>Fargesia</italic> and its allies were broken into eight clades. Several <italic>Fargesia</italic> species were clustered into the <italic>Thamnocalamus</italic> clade and the <italic>Drepanostachyum</italic> + <italic>Himalayacalamus</italic> clade that rendered the polyphyly of <italic>Fargesia</italic>. The remaining six clades, including the <italic>Fargesia</italic> spathe clade, the <italic>Phyllostachys</italic> clade, <italic>Arundinaria fargesii</italic>, the <italic>Ampelocalamus</italic> clade, the <italic>Fargesia grossa</italic> clade, and the <italic>Fargesia macclureana</italic> clade, were identified. Molecular phylogenetic analyses supported that <italic>Yushania</italic> should be included in <italic>Fargesia</italic> (s.l.) which had synapomorphy of expanded leaf sheaths in varying degree at the basis of inflorescences, and further divided into the <italic>Fargesia</italic> spathe clade, the <italic>Fargesia grossa</italic> clade, and the <italic>Fargesia macclureana</italic> clade. All sampled species of <italic>Yushania</italic> were nested within the <italic>Fargesia grossa</italic> clade. The probable model of the origin of the species in the <italic>Fargesia</italic> spathe clade with spathe-like leaf sheath syndrome was proposed. Moreover, the formation of the spathe-like leaf sheath syndrome may be correlated with cold climatic conditions in Quaternary. Our results provide new sight into the phylogenetic relationship within <italic>Fargesia</italic>.</p>