Initiation and Development of Flower Buds in Hepatica nobilis

無加温ビニルハウスで栽培したオオミスミソウは開花したあと前年に形成された葉を展開したあと,根茎先端でクラウン形成を始めた.クラウンはまず鱗片葉を形成し,花芽は4月中旬頃に鱗片葉の基部に初めて観察された.鱗片葉形成および花芽分化は7月下旬まで求頂的に続き,花芽数はクラウン当たり7個となった.その後一部の花芽が枯死し,開花直前の3月下旬のクラウン当たりの生存花芽数は約4個前後であった.4種類の温度に設定した照明付インキュベーター(16h明期/8h暗期,PFD 20-30μmols-1・m-2・sec-1)で栽培した株では,15℃恒温条件下で栽培した株で花芽分化・発達が最もよく,花芽数が最大となった.Four year-old H. nobilis plants cultivated in a non-heated polyethylene house began to develop a new apical bud (crown) on the top of rhizome after flowering and leaf development. The bud formed scale leaves, followed by development of flower bud in the axils of each scaly leaf. Flower bud was observed late in April for the first time, and the initiation and development of bud scales and flower buds continued acropetally to late July. About 5 to 7 flower buds per crown were formed until late August, and then a few flower buds wilted. About 4 flower buds per crown existed late in March. When plants were cultivated in the incubators at different temperatures under a 16 photoperiod with fluorescent lamps at a PFD of 20-30μmols-1・m-2・sec-1, the initiation and development of flower buds were stimulated best at 15℃ compared to other temperature conditions