The role of circa-annual rhythm in the occurrence of flowering disorder in Japanese pear and a possible technique to alleviate the severity by rhythm synchronization

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06040
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39030:Horticultural science-related
• Research Institution: National Agriculture and Food Research Organization
• Principal Investigator: Ito Akiko 国立研究開発法人農業・食品産業技術総合研究機構, 果樹茶業研究部門, 室長 (30355383)
• Co-Investigator(Kenkyū-buntansha): 喜多 正幸 国立研究開発法人農業・食品産業技術総合研究機構, 果樹茶業研究部門, 上級研究員 (10343972)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: ニホンナシ / 休眠 / 発芽不良 / 生理活性物質

Outline of Final Research Achievements

The warmer autumn - winter temperatures is proposed to disturb endodormancy induction and thus disrupt the subsequence floral organ development and the acquisition of freezing tolerance. To test the idea that the earlier dormancy progression may alleviate the incidence of flowering disorder, we applied ABA to pear trees. Japanese pear ‘Kosui’ trees grown at two orchards which are locating in the region of frequently occurring flowering disorder. The applications were repeated two seasons. The results demonstrated that the flowering in the following spring became earlier and the floret number per flower bud increased in the ABA applied trees, compared with control (no ABA applications). These results indicate that ABA alleviates the incidence of flowering disorder.

Free Research Field

園芸学

Academic Significance and Societal Importance of the Research Achievements

本研究は、①発芽不良は低温感受性時期が自発休眠覚醒と花芽成熟で異なること、②ABA処理により低温感受性時期のリセットまたは低温遭遇時間の補填効果が生じ、耐凍性の向上や花芽成熟の促進により発芽不良発生が軽減されること、を明らかにした。
主に野外で栽培される果樹においては、低温不足を低温処理で補うことはエネルギー効率の点からほとんど不可能である。しかしABA処理などの刺激によって限られた低温量であっても花芽成熟を適切に進行させることが可能となり、発芽不良を改善する可能性が示されたことから、今後、有用な対策技術となり得る。