| 要旨トップ | 本企画の概要 | 日本生態学会第61回全国大会 (2014年3月、広島) 講演要旨
ESJ61 Abstract


企画集会 T20-2 (Lecture in Symposium/Workshop)

開花遺伝子を軸にした大規模同調開花メカニズムの解明

佐竹暁子(北大・環境),宮﨑祐子(岡山大・環境生命),丸山洋介(北大・理),千葉由佳子(北大・理),小林正樹(チューリヒ大),清水健太郎(チューリヒ大),持田恵一(理研),今博計(道立林試),日浦勉(北大・フィールド)

The large fluctuation in reproductive output at plant population level, called masting, has been identified in a wide range of species. The role of resource availability as one of the proximate factors for masting has attracted much attention with strong theoretical support from the resource budget model. Recently, the molecular genetic underpinning of flowering timing has been uncovered in model plant systems. Here we applied expression analysis of flowering genes to Siebold’s beech, a typical masting species in cool-temperate forests in Japan, to study the effect of resource availability on floral initiation. Four-year monitoring of flowering gene expression in naturally grown trees revealed a clear cycle of on and off years, which wwas correlated with high and low nitrogen concentration in the current year shoots, although carbohydrate availability did now show any clear relationship. Nitrogen fertilization using grafted trees resulted in a significantly higher expression in the flowering genes than controls, and all the fertilized trees flowered but no flowers were produced in the control trees. Our findings identified nitrogen as a key regulator of masting, and provide a new empirical evidence that supports the theoretically proposed mechanism of masting.


日本生態学会