學術資源整合系統-相關推薦
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| 作者 | Chang, Chih-Yi;Liao, Pei-Chun;Tzeng, Hsy-Yu;Kusumi, Junko;Su, Zhi-Hui;Tseng, Yen-Hsueh |
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| 出版日期 | 2025 |
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| 著作名稱 | Chromosome number variation and phylogenetic divergence of East Asian Cirsium sect. Onotrophe subsect. Nipponocirsium (Compositae), with a new species from Taiwan [SCI]
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| 刊名 | Botanical Studies |
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| 卷 | 66 |
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| 頁數 | 8 |
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| 被收錄索引 | SCI |
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| 主題 | 植物 |
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| 關鍵字 | Descending dysploidy; Phylotranscriptomics; Polyploidization; Pollen morphology; Taxonomy |
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| 摘要 | Background: This study explored chromosome number variation, phylogenetic divergence, and the mechanisms underlying speciation in the East Asian thistle Cirsium Mill. sect. Onotrophe (Cass.) DC. subsect. Nipponocirsium Kitam. (Compositae), with a focus on the newly identified Taiwanese species Cirsium pengii Y.H. Tseng, P.C. Liao and Chih Y. Chang.
Methods: Phylotranscriptomic data were used to reconstruct evolutionary relationships between Taiwanese and Japanese taxa of subsect. Nipponocirsium, and to estimate divergence times and chromosomal characteristics. The chromosome number, morphology, and pollen morphology of the unknown Taiwanese taxon were also compared with other known Taiwanese members of the subsection.
Results: Phylotranscriptomic analysis revealed a clear division of subsect. Nipponocirsium into Japanese and Taiwanese clades. Within the Taiwanese clade, C. pengii was basal, while C. tatakaense remained monophyletic with other Taiwanese species despite showing higher genetic diversity. The prevalent chromosome number in this subsection is tetraploid (2n = 4x = 68) in Japanese taxa, whereas Taiwanese members have 2n = 4x = 64. Notably, C. pengii has a diploid number (2n = 32), indicating descending dysploidy followed by polyploidization in Taiwan. This polyploidization, likely driven by glaciation events, appears to have shaped the evolution of Nipponocirsium. Divergence time estimates suggest that the Japanese and Taiwanese clades separated around 0.74 million years ago during glacial periods. Cirsium pengii diverged around 0.47 million years ago, whereas the tetraploid species C. kawakamii and C. tatakaense diverged around 0.35 million years ago. These species likely evolved in separate refugia, and distinct species boundaries were supported by species delimitation analysis as well as comparisons of karyotype, morphology, and pollen morphology.
Conclusions: These findings improve our understanding of chromosomal evolution and speciation within subsect. Nipponocirsium and highlight the value of integrating transcriptomic data into phylogenetic studies. This study provides a comprehensive framework for future investigations into the genetic diversity and adaptive mechanisms of this ecologically important group. |
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| 全文 |  ; |
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| DOI | 10.1186/s40529-025-00454-2 |
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| 計畫主持人 | Yen-Hsieh Tseng |
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| 計畫編號 | 110-2313-B-005-033-MY3 |
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| 計畫年度 | 110 |
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| 計畫委託單位 | the grant of National Science and Technology Council |
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| 計畫名稱 | 東亞菊科薊屬植物的系統分類及種化機制之研究 |
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| 系統號 | NO000007546 |
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