Seasonal Variability in Dormancy and Flowering Competence in Chrysanthemum

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H04877
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Horticultural science
• Research Institution: National Agriculture and Food Research Organization
• Principal Investigator: HISAMATSU TAMOTSU 国立研究開発法人農業・食品産業技術総合研究機構, 野菜花き研究部門, 上級研究員 (00355710)
• Co-Investigator(Kenkyū-buntansha): 樋口 洋平 東京大学, 大学院農学生命科学研究科(農学部), 講師 (00746844) ; 住友 克彦 国立研究開発法人農業・食品産業技術総合研究機構, 野菜花き研究部門, 上級研究員 (70391406)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: キク / ロゼット / 休眠 / 花成

Outline of Final Research Achievements

To enhance our understanding of seasonality in chrysanthemums, we have introduced comparative transcriptome analysis to elucidate the mechanism.
In chrysanthemum, the dormant meristem lacks the ability for shoot extension and flowering. Both shoot extension and flowering capacity under the subsequent growing conditions were regulated by the temperature of prior growing conditions. After the temperature increased over the summer, chrysanthemums showed a reduced ability for extension growth, and became more difficult to induce flowering. Chilling stimulated the extension growth of shoots when the meristems were entering a dormant state. Chilling had the opposite effect on two regulatory pathways involved in flowering capacity. A pathway related to the meristem dormant state was suppressed by exposure to chilling and induced flowering, and chilling activated an inhibitory regulator in parallel.

Free Research Field

花き園芸学

Academic Significance and Societal Importance of the Research Achievements

キクの越冬機構であるロゼット形成/花成抑制機構は多年生草本植物であるキクの生存戦略上、非常に重要であり個体の成長や種の繁栄に必要不可欠な適応機構である。一方、切り花生産においては、冬季安定生産の妨げとなっている。そこで、ロゼット形成と花成能力の変化に着目したキクの季節的成長制御機構の解明に取り組み、多年生草本植物のライフサイクル制御機構の理解に貢献するとともに、キクをはじめとする産業上重要な多年生草本花き類の周年安定生産を支える基盤となる知見の集積を目指す。