Adaptive significance of sexual reproduction in bamboos that have long-term asexual reproduction

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K06120
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 40010:Forest science-related
• Research Institution: The University of Tokyo
• Principal Investigator: Hisamoto Yoko 東京大学, 大学院農学生命科学研究科(農学部), 助教 (60586014)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: bamboo / 一斉開花 / 有害遺伝子 / 体細胞突然変異 / ジェネット

Outline of Final Research Achievements

Bamboos bloom and show sexual reproduction after a long-termed asexual reproduction that propagate with bamboo shoots and rhizomes. Phyllostachys pubescens bear fruit after flowering and recovers from the seedlings, whereas P. nigra var. henonis does not bear fruit after flowering and recovers through asexual reproduction.
This study tested the hypothesis that the role of sexual reproduction in bamboos is to eliminate somatic mutations accumulated through long-termed asexual reproduction. Sequence polymorphisms were examined in P. pubescens with different flowering cycles. The results showed that the amount of polymorphisms did not change between lineage, indicating that somatic mutations do not accumulate significantly in Moso bamboo even with long-term vegetative reproduction. On the other hand, comparison of sequence polymorphisms before and after flowering revealed that many somatic gene variants were found in one ramet in P. nigra var. henonis.

Free Research Field

森林分子生態学

Academic Significance and Societal Importance of the Research Achievements

長期の無性繁殖後に有性繁殖をするという特異な生活史特性を持つタケ類において有性繁殖の役割が明らかになれば、タケ類のみならずクローナル植物における適応的意義の解明に繋がると考えられる。また、例えばモウソウチクの地下茎は一年間で平均約2m、長いものは5m以上伸長するが、このようなタケ類の旺盛な栄養繁殖により近年利用されず放置された竹林が周囲の森林等へ拡大する問題が生じている。そのため、タケ類の繁殖特性を明らかにすることは竹林拡大問題の解決にもつながる可能性がある。