Format: ORAL

Yue Zhao1,2, Ya-Ping Chen1, Bryan Drew3, Orzimat T. Turginov4, Yasaman Salmaki5, Chun-Lei Xiang1*

1CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China 2Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau & Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot 010000, Inner Mongolia, China 3Department of Biology, University of Nebraska at Kearney, Kearney, Nebraska, U.S.A. 4Institute of Botany, Academy of Sciences of the Republic of Uzbekistan, Tashkent 100047, Uzbekistan 5Center of Excellence in Phylogeny of Living Organisms, Department of Plant Science, College of Science, University of Tehran, P.O.Box 14155-6455, Tehran, Iran *Correspondence: Chun-Lei Xiang, xiangchunlei@mail.kib.ac.cn

As currently circumscribed, Phlomoidesincluded seven traditionally defined genera, making the genus is the second largest and perhaps most taxonomically challenging genus within subfamily Lamioideae (Lamiaceae). The genus has undergone major species radiation in Central Asia, the Iranian highland, and China. To date, a robust and broad phylogeny of Phlomoidesremains absent. Moreover, given the myriad new additions to the genus, the existing infrageneric classification needs to be evaluated and revised. In this study, we attempted to elucidate the phylogenetic relationships within Phlomoidesusing complete plastome sequences and nrDNA regions with a broad taxon sampling of ca. 80% species of the genus. We employed Maximum likelihood (ML) and Bayesian inference (BI) methods to reconstruct the backbone phylogeny of Phlomoides. Our results revealed largely congruent topologies of plastid and nuclear DNA data sets, and six major clades were recognized. Several morphological characters(i.e., the root type, appearance of basal leaves, shape of basal and floral leaves, the shape and size of floral bracts, the shape of calyx teeth and spines, the appendages of filaments, the lobes of style, etc.) support the phylogenetic conclusions, indicating the genus can be subdivided into six sections. Hybridization and incomplete lineage sorting may represent potential sources of the incongruence between the plastome and nrDNA data. A purposely integrative design to explore the taxonomy within the genus is required in future.