Plant Diversity ›› 2023, Vol. 45 ›› Issue (04): 397-408.DOI: 10.1016/j.pld.2023.03.013

• Articles • Previous Articles     Next Articles

Molecular phylogeny and inflorescence evolution of Prunus (Rosaceae) based on RAD-seq and genome skimming analyses

Na Sua,b, Richard G.J. Hodelc, Xi Wanga,b, Jun-Ru Wanga,b, Si-Yu Xiea,b, Chao-Xia Guia,b, Ling Zhangd, Zhao-Yang Changa,b, Liang Zhaoa,b, Daniel Pottere, Jun Wenc   

  1. a. College of Life Sciences, Northwest A&F University, Yangling 712100, China;
    b. Herbarium of Northwest A&F University, Yangling 712100, China;
    c. Department of Botany, National Museum of Natural History, MRC 166, Smithsonian Institution, Washington, DC 20013-7012, USA;
    d. College of Life Sciences, Tarim University, Alaer 843300, China;
    e. Department of Plant Sciences, MS2, University of California, Davis, CA 95616, USA
  • Received:2022-09-06 Revised:2023-03-29 Online:2023-07-25 Published:2023-08-21
  • Contact: Liang Zhao,E-mail:biology_zhaoliang@126.com
  • Supported by:
    We thank Prof. Zhong-Hu Li and Dr. Miao–Miao Ju of Northwest University and Dr. Li Feng of Xi'an Jiaotong University, Dr. Fu-Zhen Guo and Xiao-Hua He from Instrument Sharing Platform of Northwest A&F University and Molecular Biology Experiment Center, Germplasm Bank of Wild Species in Southwest China for help with data analysis, and Mr Hai-Ning Li, Xiao-Jie Li and Prof. You Zhou for providing plant photographs (Fig. 1L–O). We also thank Dr. Florian Jabbour and Dr. Valéry Malécot for their valuable comments. Computational analyses were partially conducted on the Smithsonian Institution High Performance Computing Cluster (SI/HPC, “Hydra”: https://doi.org/10.25572/SIHPC). This work was supported by grants from National Natural Science Foundation of China (No. 32170381 and 31770200).

Abstract: Prunus is an economically important genus widely distributed in the temperate Northern Hemisphere. Previous studies on the genus using a variety of loci yielded conflicting phylogenetic hypotheses. Here, we generated nuclear reduced representation sequencing data and plastid genomes for 36 Prunus individuals and two outgroups. Both nuclear and plastome data recovered a well-resolved phylogeny. The species were divided into three main clades corresponding to their inflorescence types, - the racemose group, the solitary-flower group and the corymbose group - with the latter two sister to one another. Prunus was inferred to have diversified initially in the Late Cretaceous around 67.32 million years ago. The diversification of the three major clades began between the Paleocene and Miocene, suggesting that paleoclimatic events were an important driving force for Prunus diversification. Ancestral state reconstructions revealed that the most recent common ancestor of Prunus had racemose inflorescences, and the solitary-flower and corymb inflorescence types were derived by reduction of flower number and suppression of the rachis, respectively. We also tested the hybrid origin hypothesis of the racemose group proposed in previous studies. Prunus has undergone extensive hybridization events, although it is difficult to identify conclusively specific instances of hybridization when using SNP data, especially deep in the phylogeny. Our study provides well-resolved nuclear and plastid phylogenies of Prunus, reveals substantial cytonuclear discord at shallow scales, and sheds new light on inflorescence evolution in this economically important lineage.

Key words: Prunus, Rosaceae, RAD-Seq, Chloroplast genome, Hybridization, Inflorescence evolution