Evolutionary study on cleistocarpous bryophytes with special reference to the Pottiaceae (Bryophyta)

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K07481
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Biodiversity/Systematics
• Research Institution: Hiroshima University
• Principal Investigator: Tsubota Hiromi 広島大学, 理学研究科, 准教授 (10332800)
• Research Collaborator: Estébanez Belén ; DEGUCHI Hironori ; INOUE Yuya ; Kučera Jan ; Jiménez Juan A. ; Kim Wonhee ; KUBO Harumori ; NAKAHARA Miho (TSUBOTA Miho) ; YAMAGUCHI Tomio
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: センボンゴケ科 / 胞子体 / 閉鎖果 / セン類 / 系統解析

Outline of Final Research Achievements

Evolutionary studies on cleistocarpous bryophytes with special reference to the family Pottiaceae (Bryophyta) were conducted. The Pottiaceae are the most generic and species rich family in Bryophyta. Molecular phylogenetic inference based on a new approach using a codon substitution model is also undertaken and confirm four clades within the Pottiaceae, and a newly proposed subfamily Streblotrichoideae. Parallel or convergent evolution and sterility were observed in the family. As a case study, the Japanese Weissia was reviewed. Four species, including one newly described, of Japanese cleistocarpous species of Weissia are recognized based on molecular phylogenetic inference and morphological reassessment. Rapid sporophyte modifications in Weissia and monophyletic positions of these four species are supported by the analysis using concatenated chloroplast rbcL and rps4 gene sequences.

Free Research Field

植物系統・分類学

Academic Significance and Societal Importance of the Research Achievements

蘚類を含むコケ植物は陸上植物の初期進化を考える上で重要な群である。コケ植物は退化的な胞子体を持つことが知られているが，その中でもとくにさまざまな段階の退化的な胞子体を持つコゴケ属を含む蘚類センボンゴケ科を例に研究を行った。本研究ではコケ植物でこれまで用いられていなかったコドンモデルを用いた分子系統解析を行うことで，より精度の高い系統関係の推定を行うことができた。また，新亜科や新種の提案を行い，植物分類学上の貢献を行うことができた。退化的な胞子体である閉鎖果が同属内で複数回生じていることを明らかにし，比較的短期間で形態進化が生じうることを見いだした。