Song Yi-Gang, Li Ying, Meng Hong-Hu, Fragnière Yann, Ge Bin-Jie, Sakio Hitoshi, Yousefzadeh Hamed, Bétrisey Sébastien, Kozlowski Gregor
Eastern China Conservation Center for Wild Endangered Plant Resources, Shanghai Chenshan Botanical Garden, Chenhua Road No.3888, Songjiang, Shanghai 201602, China.
Department of Biology and Botanic Garden, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland.
Plants (Basel). 2020 Nov 9;9(11):1524. doi: 10.3390/plants9111524.
Relict species play an important role in understanding the biogeography of intercontinental disjunctions. (a relict genus) is the valuable model taxon for studying the biogeography of East Asian versus southern European/West Asian disjunct patterns. This disjunction has not been as well studied as others (e.g., between Eastern Asia and North America). Several phylogenetic studies on have been conducted, but none have provided a satisfactory phylogenetic resolution. Here, we report the first well-resolved phylogeny of using restriction site-associated DNA sequencing data based on the sampling of all taxa across the entire distribution area of the genus. Taxonomic treatments were also clarified by combining morphological traits. Furthermore, fossil-calibrated phylogeny was used to explore the biogeography of . Our results support the existence of two sections in , which is in accordance with morphological taxonomy. Section comprises three species: , , and . Section also comprises three species: , , and . The divergence between the two sections took place during the early Miocene (20.5 Ma). The formation of the Gobi Desert and climate cooling of northern Siberia in the Middle Miocene (15.7 Ma) might have caused the split of the continuous distribution of this genus and the formation of the East Asian versus southern European/West Asian disjunct pattern. Lastly, the divergence between and as well as between and / (10.0 Ma) supports the late Miocene diversification hypothesis in East Asia.
残遗物种在理解洲际间断分布的生物地理学方面发挥着重要作用。（一个残遗属）是研究东亚与南欧/西亚间断分布模式生物地理学的宝贵模式分类群。这种间断分布的研究不如其他一些间断分布（如东亚和北美之间的间断分布）深入。已经对……进行了几项系统发育研究，但都没有提供令人满意的系统发育分辨率。在这里，我们基于对该属整个分布区域内所有分类群的采样，利用限制性位点相关DNA测序数据报告了首个分辨率良好的……系统发育。通过结合形态特征也明确了分类处理。此外，利用化石校准的系统发育来探索……的生物地理学。我们的结果支持……中存在两个组，这与形态分类学一致。组……包括三个物种：……、……和……。组……也包括三个物种：……、……和……。两组之间的分歧发生在中新世早期（2050万年前）。中新世中期（1570万年前）戈壁沙漠的形成和西伯利亚北部的气候变冷可能导致了该属连续分布的分裂以及东亚与南欧/西亚间断分布模式的形成。最后，……与……之间以及……与……/……之间的分歧（1000万年前）支持了东亚晚中新世多样化假说。
