Identification of floral inducing factors of radish that breaks through the strong floral repression of cabbage and its application to seed production

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K15518
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 39030:Horticultural science-related
• Research Institution: Kyoto University
• Principal Investigator: Motoki Ko 京都大学, 農学研究科, 助教 (00867814)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: キャベツ / ダイコン / 晩抽性育種 / 接ぎ木 / フロリゲン・FLOWERING LOCUS T / 早期開花技術 / 採種 / アブラナ科

Outline of Final Research Achievements

In order to develop a "non-flowering vegetable seed" production system, factors involved in the ability of grafted radish to induce flowering were identified and agronomic traits of cabbage seeds obtained by grafting were evaluated. Through quantitative analysis of FT protein, a flowering hormone, it was found that FT has a quantitative effect on the floral induction in cabbage by grafting, and that accumulation of sufficient amounts of FT in the grafted cabbage is necessary for the success of floral induction. In addition, the rootstock factors that affect the amount of FT accumulated in the grafted scion were identified. The results of cultivation experiments showed that the grafting method had no effect on the major agronomic traits of the resulting cabbage seeds, suggesting that it can be used for cabbage breeding in the same way as the conventional method.

Free Research Field

園芸科学

Academic Significance and Societal Importance of the Research Achievements

本研究では接ぎ木による花成誘導の成否に関わる台木の要因の特定と、接ぎ木により採種した種子の形質評価を通して、接ぎ木を利用した“花の咲かない野菜種子”生産体系の実現可能性を示すことができた。今回明らかにした台木のFT供給能力に関わる要因に着目することで、より強力な花成誘導能力をもつ台木を作出し、接ぎ木による種子生産を効率化できる可能性がある。本研究で開発した花成誘導法は、従来の低温処理による花成誘導法で要した時間を半分に短縮可能であり、アブラナ科作物の育種や採種にも有用だと考えられる。また本研究で得た知見は、アブラナ科以外の作物種における接ぎ木花成誘導法の開発にも資するものと考える。