Plastome-based subgenus-level phylogenetic backbone of hawthorns: insights into the maternal position and taxonomic synopsis of Crataegusshandongensis (Rosaceae, Maleae)

Xiao-Hua Lin; Si-Yu Xie; Guang-Ning Liu; Dai-Kun Ma; Fei-Ran Zou; Wei-Dong Peng; Chao Xu; Bing Liu; Liang Zhao; Bin-Bin Liu

doi:10.3897/phytokeys.252.136506

Plastome-based subgenus-level phylogenetic backbone of hawthorns: insights into the maternal position and taxonomic synopsis of Crataegusshandongensis (Rosaceae, Maleae)

PhytoKeys. 2025 Feb 12:252:87-108. doi: 10.3897/phytokeys.252.136506. eCollection 2025.

Authors

Xiao-Hua Lin^{1

2

3}, Si-Yu Xie^{1

2

3}, Guang-Ning Liu³, Dai-Kun Ma^{2

3

4}, Fei-Ran Zou^{2

3

5}, Wei-Dong Peng⁵, Chao Xu^{2

3}, Bing Liu^{2

3}, Liang Zhao¹, Bin-Bin Liu^{2

3}

Affiliations

¹ College of Life Sciences & Herbarium of Northwest A&F University, Northwest A&F University, Yangling, Shaanxi 712100, China.
² State Key Laboratory of Plant Diversity and Specialty Crops, Chinese Academy of Sciences, Beijing 100093, China.
³ China National Botanical Garden, Beijing 100093, China.
⁴ Key Laboratory of National Forestry and Grassland Administration on Plant Ex situ Conservation, China National Botanical Garden (North Garden), Beijing 100093, China.
⁵ University of Chinese Academy of Sciences, Beijing 100049, China.

Abstract

The recent recognition of the five-subgenera classification within Crataegus has prompted discussion about the maternal phylogenetic relationships among these subgenera, with inconsistencies in taxon sampling, marker selection, and inference methods contributing to differing interpretations. In this study, we performed deep genome skimming sequencing and assembled 63 whole plastomes, including 58 from Crataegus and five from related genera as the outgroups. We employed multiple phylogenetic inference methods (Maximum Likelihood and Bayesian Inference) to reconstruct an accurate phylogeny. The whole plastome-based, maternally inherited trees consistently supported two major clades within Crataegus: one comprising C.subg.Crataegus and C.subg.Brevispinae, the other encompassing the remaining three subgenera. Within the latter clade, C.subg.Sanguineae and C.subg.Americanae formed a sister group, which together were sister to C.subg.Mespilus. Our analysis also revealed a close maternal relationship between C.shandongensis and C.pinnatifidavar.major, suggesting the shared maternal ancestry. Furthermore, we updated the description of C.shandongensis based on extensive specimen examination and designated the lectotype for this species. This comprehensive taxonomic synopsis, supported by both phylogenomic and morphological analyses, provides a robust foundation for future taxonomic and evolutionary studies of the Shandong hawthorn.

Keywords: Chloroplast genome; Crataegus; deep genome skimming; lectotype; taxonomy.

Xiao-Hua Lin, Si-Yu Xie, Guang-Ning Liu, Dai-Kun Ma, Fei-Ran Zou, Wei-Dong Peng, Chao Xu, Bing Liu, Liang Zhao, Bin-Bin Liu.

Associated data

Dryad/10.5061/dryad.z612jm6nc

Grants and funding

National Natural Science Foundation of China (grant number 32270216 to BBL, 32000163 to BBL, and 32170381 to LZ), the Youth Innovation Promotion Association CAS (grant number 2023086 to BBL), and the Biological Taxonomy Scientist Position CAS (grant number CAS-TAX-24-013 to BBL).