| Project/Area Number |
15K07180
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Biodiversity/Systematics
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| Research Institution | Chiba University |
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Principal Investigator |
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| Research Collaborator |
Ebihara Atsushi
Imai Ryosuke
Matsumoto Sadamu
Nagano Atsushi
Takayama Koji
Tezuka Ayumi
Tsuda Yoshiaki
Suyama Yoshihisa
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| Project Period (FY) |
2015-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000)
Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2016: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2015: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
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| Keywords | 自殖 / 交配様式 / シダ植物 / SNP / 遺伝的多様性 / ボトルネック / RAD-seq / 連鎖地図 / 同型胞子シダ植物 / マイクロサテライト / MIG-seq |
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| Outline of Final Research Achievements |
Diploid sexual races of Cyrtomium falcatum exhibit mating system variation: two different types of sexual expression (gametangia formation) in gametophytes. Inference of population splitting using SNPs data suggested that mixed mating-subspecies littorale had been derived from obligate outcrossing-subspecies australe. Furtherrmore, both EBSP and Stairway plot detected a severe population bottleneck event during the Last Glacial Period in the subspecies littorale, indicating a clear association between evolution of selfing and population bottleneck. In order to map genetic loci responsible for sexual expression in gametophytes, we constructed a linkage map by using RAD-seq data of a gametophyte population from an artificial F1 hybrid between the two subspecies. Unfortunately, however, no significant QTL were detected for the two different types of sexual expression. This suggests that the difference of the sexual expression between two subspecies are governed by relatively many loci.
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| Academic Significance and Societal Importance of the Research Achievements |
他殖から自殖への進化は、被子植物では経験的にも理論的にも多くの研究がなされている。同形胞子シダ植物の配偶体もまた雌雄同株であり、様々な交配様式を示す点でも被子植物と同じであるが、自殖の進化に関わる機構については大きく研究が遅れている。本研究ではオニヤブソテツの二倍体有性生殖型の亜種間での交配様式の変異について解析し、自殖型亜種が他殖型亜種から派生して生じた事、また自殖型亜種は、最終氷期に明確なボトルネックを経験した事を示した。シダ植物において自殖の進化と歴史的ボトルネックの相関が検出されたのは初めての事例であり、自殖の進化において基本的に被子植物と同じ機構が働いている可能性が示唆される。
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