摘要
Ulmaceae is a woody family widespread in northern temperate forests. Despite the ecological importance of this family, its phylogeny and biogeographic history are poorly understood. In this study, we reconstruct phylogenetic relationships within the family and infer spatio-temporal diversification patterns based on chloroplast genome (complete cpDNA) and nuclear ribosomal DNA sequences (nrDNA). The seven Ulmaceae genera are resolved in two main clades (temperate vs. tropical) by both cpDNA and nrDNA sequences. The temperate clade includes four genera, Hemiptelea, Zelkova, Planera, and Ulmus. The relationships among Planera and other genera are controversial because of inconsistent topologies between plastid and nuclear data. The tropical clade includes three genera ((Ampelocera, Phyllostylon), Holoptelea). Molecular dating and diversification analyses show that Ulmaceae originated in the Early Cretaceous (ca. 110–125 Ma) with the main lineages establishing from the Late Cretaceous to the early Eocene. The diversification rate slowed during the middle to the late Paleogene (ca. 23–45 Ma), followed by a rapid diversification of the East Asian temperate group in the Neogene, congruent with a global cooling event. The ancestral state optimization analysis suggests an East Asian origin of the temperate Ulmaceae clade during the Paleocene, which is consistent with the fossil record. Both phylogenomic and fossil evidence support East Asia as a center of origin and diversification for the temperate woody lineages.
摘要译文
Ulmaceae是北部温带森林的木质家庭。尽管该家族具有生态重要性，但其系统发育和生物地理史还是很了解。在这项研究中，我们重建家族中的系统发育关系，并根据叶绿体基因组（完整的CPDNA）和核核糖体DNA序列（NRDNA）推断时空多样化模式。 CPDNA和NRDNA序列都在两个主要进化枝（温带与热带）中分辨出七个Ulmaceae属。温带进化枝包括四个属，Shemiptelea，Zelkova，Planera和Ulmus。平面与其他属之间的关系是有争议的，因为质体和核数据之间的拓扑不一致。热带进化枝包括三个属（Ampelocera，Phyllostylon），Holoptelea）。分子日期和多样化分析表明，乌尔摩科起源于白垩纪早期（约110-125 mA），主要谱系从白垩纪晚期到早期始新世建立。多元化速率在中期至晚期（大约23-45 mA）的中期放缓，随后是新近纪的东亚温带群体快速多样化，与全球冷却事件一致。祖先的优化分析表明，古新世期间温带乌尔玛科进化枝的东亚起源与化石记录一致。系统基因组和化石证据都支持东亚作为温带木质谱系的原产中心和多样化。
Qiu-Yue Zhang[1];Min Deng[2];Yanis Bouchenak-Khelladi[3];Zhe-Kun Zhou[1];Guang-Wan Hu[4];Yao-Wu Xing[1]. The diversification of the northern temperate woody flora – A case study of the Elm family (Ulmaceae) based on phylogenomic and paleobotanical evidence[J]. Journal of Systematics and Evolution, 2022,60(4): 728-746