Homoploid hybridization adds clarity to the origins of octoploid strawberries

• 成果类型: Article
• 署名作者: Fan, Zhen; Liston, Aaron; Soltis, Douglas E.; Soltis, Pamela S.; Ashman, Tia - Lynn; Hummer, Kim E.; Whitaker, Vance M.
• 署名单位: Zhejiang A&F University; State University System of Florida; University of Florida; Oregon State University; State University System of Florida; University of Florida; Pennsylvania Commonwealth System of Higher Education (PCSHE); University of Pittsburgh; United States Department of Agriculture (USDA)
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-12895
• DOI: 10.1073/pnas.2502814122
• 发表日期: 2025-06-24
• 关键词: evolutionary; polyploidy; fragaria; DYNAMICS

摘要

The evolutionary histories of many polyploid plant species are difficult to resolve due to a complex interplay of hybridization, incomplete lineage sorting, and missing diploid progenitors. In the case of octoploid strawberry with four subgenomes designated ABCD, the identities of the diploid progenitors for subgenomes C and D have been subject to much debate. By integrating new sequencing data from North American diploids with reticulate phylogeny and admixture analyses, we uncovered introgression from an extinct or unsampled species in the clade of Fragaria viridis, Fragaria nipponica, and Fragaria nilgerrensis into the donor of subgenome A of octoploid Fragaria prior to its divergence from F. vesca subsp. bracteata. We also detected an introgression event from F. iinumae approach, we estimate that the octoploid and its intermediate hexaploid and tetraploid ancestors emerged approximately 0.8, 2, and 3 million years ago, respectively. These results provide an explanation for previous reports of F. viridis and F. nipponica as donors of the C and D subgenomes and suggest a greater role than previously thought for homoploid hybridization in the diploid progenitors of octoploid strawberry. The integrated set of approaches used here can help advance polyploid genome analysis in other species where hybridization and incomplete lineage sorting obscure evolutionary relationships.