溫度對繡球花花芽形成之影響

Effects of Temperature on Flower Formation of Hydrangea macrophylla ‘Leuchtfeuer’

於人工氣候室與梅峰（海拔2100公尺）研究溫度對繡球花花芽形成之影響，以建立繡球花在台灣本土之花期調節基礎資料。於人工氣候室15／13℃處理24天後，植株莖頂已達分化五個花序原體階段。而20／15℃處理者，已分化五個花序原體或進入花序原體產生分枝階段。於78天後，25／20℃處理者僅有20%的植株進入花芽創始階段，30／25℃處理之植株仍處於營養生長。南投縣魚池鄉業者於1997年七月上旬運至梅峰高冷地之植株，經15-39天後花芽已創始。桃園縣新屋鄉業者於2001年七月將植株運至梅峰，結果植株經50-60天後花芽已創始；於八月運達者，經63-74天後達花芽創始階段。營養生長之繡球花的莖頂發育階段和莖頂直徑呈線性相關，當莖頂直徑為0.32-0.46 mm時，始迅速膨大並分化花序原體。 Effect of temperature on flower formation of Hydrangea macrophylla ‘Leuchtfeuer’ was studied in phytotron and Mei-feng highland field conditions in order to establish the information of regulation of flowering in hydrangeas in Taiwan. After the 15/13℃ treatment for 24 days, the hydrangeas had initiated five primary inflorescence primordia, while the 20/15℃-treated plants had initiated both primary and secondary inflorescence primordia. After treatments for 78 days, 20% of the 25/20℃-treated plants had initiated inflorescences, while all of the 30/25℃ -treated plants remained vegetative growth. Hydrangeas, supplied by a grower at Yu-Chih area in Nantu, had initiated inflorescences in 15 to 38 days after plants’ transferring to Mei-Feng in July 1997. Hydrangeas, supplied by a grower at Hsin-Wuhr area in Taoyuan, had initiated inflorescences in 50 to 69 days after transferring to Mei-feng in July, and in 63 to 74 days for those transferring in August 2001. Shoot apical diameter (＜0.32-0.46 mm) was linearly related to the shoot developmental stage in the phytotron or highland field-grown vegetative plants, but after inflorescence initiation, the shoot apical diameter expanded rapidly.