Speciation of Fritillaria sect. Japonica: Investigating the causes of discordance of floral morphology evolution and phylogeny, and the causes of formation of unique distribution patterns of species

2023 Fiscal Year Final Research Report

• Project/Area Number: 18K06379
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 45030:Biodiversity and systematics-related
• Research Institution: Kyoto University
• Principal Investigator: Fuse Shizuka 京都大学, 理学研究科, 准教授 (30344386)
• Co-Investigator(Kenkyū-buntansha): 田村 実 京都大学, 理学研究科, 教授 (20227292) ; 高山 浩司 京都大学, 理学研究科, 准教授 (60647478)
• Project Period (FY): 2018-04-01 – 2024-03-31
• Keywords: コバイモ節 / 花形態 / 分子系統 / 訪花昆虫 / 日本固有 / 絶滅危惧植物 / スプリング・エフェメラル

Outline of Final Research Achievements

Fritillaria sect. Japonica (Liliaceae) is composed only of species endemic to Japan. Based on morphological character observation, maternal lineage estimation through plastid sequence analysis by Sanger method, and genetic diversity estimation through genome-wide analysis by MIG-seq, this plant group is now considered to consist of eight species, two infraspecific taxa, and three hybrids, rather than the previously recognized eight species and two hybrids. This indicates that the two plant groups should be treated independently: one was established by ancient hybridization; the other is being produced by ongoing hybridization, although the parent combination of the former is the same with that of the latter. Additionally, in both lineages with basic chromosome numbers of x=11 and x=12, tubular flowers were estimated to be ancestral. The flower-visiting insect fauna was clarified for a few species including Fritillaria amabilis Koidz., which has tubular flowers.

Free Research Field

植物系統分類学

Academic Significance and Societal Importance of the Research Achievements

コバイモ類（Fritillaria sect. Japonica）は日本の早春を彩る可憐な植物であるが、その多くが絶滅危惧種であり、生育環境の減少と盗掘被害によってこのままでは今後ますます個体数が減少すると予想される。本研究は、現在自生するコバイモ類の分類を再検討し、多様化に直接関与したであろう花形態の進化の方向性を示し、訪花昆虫など植物の繁殖に関わる知見を示した。これらは、植物の種分化に関する研究のみならず、コバイモ類の保全に大きく貢献する。