Survival capability of kelp microscopic early life stage as seed bank

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K06176
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 40030:Aquatic bioproduction science-related
• Research Institution: Hokkaido University
• Principal Investigator: Mizuta Hiroyuki 北海道大学, 水産科学研究院, 教授 (00250499)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: コンブ / 世代交代 / ストレス防御 / 生存能力 / シードバンク

Outline of Final Research Achievements

Microscopic generation of Makombu (male and female gametophytes) can mostly survive for 3 months under continuous dark, and after then the survival rate gradually decreased with declining of the functions in chloroplast and with production of radical oxygen species. On the other hand, dim light condition contributed to extend the maintenance of high survival rate for long times. Moreover, oxidative burst-induced extracellular silicon deposition mechanism is suggested to be active in the reproductive organ (sorus) of the macroscopic generation (sporophyte) for the successful reproduction. Actually, the sorus tissues were considerably resistant to feeding by sea urchins, because the gametophyte and juvenile sporophytes appeared in the feces of sea urchins fed the sorus tissues. These observations suggest the contribution of parent generation to microscopic stage in Makombu.

Free Research Field

水産植物学

Academic Significance and Societal Importance of the Research Achievements

コンブ類は、巨視的世代と微視的世代との間で世代交代を行い、両世代の量や質は次世代の生物量を大きく左右する。特に微視的世代は、そのサイズの小ささから藻場における生存性について不明な点が多い。その為、シードバンクとしての微視的世代の生存性やそれを支える生理機構の解明、また巨視的世代と微視的世代の相互関係や藻食動物との関連性を具体的に把握することは、沿岸域における藻場を形成・維持に有用な知見を提供することになる。加えて、コンブ微視的世代のストレス抵抗性や生存能力の把握は、養殖の際の種苗生産や種苗保存にも大きく貢献する。