溫度與光積值對洋桔梗開花時間之影響模式

Modelling of Flowering Time in Response to Temperature and Photosynthetic Daily Light Integral in Eustoma grandiflorum

探討溫度與光積值對洋桔梗花芽創始及發育之影響模式，有利安排栽培時程。本研究取洋桔梗早生‘Claris Pink’、中生‘Rin’及晚生‘Ceremony Blue Flash’經涼溫培育具3對葉之穴盤苗，於夏季移至自然光照（日長10.5-13.5 h）、平均溫度14.0、17.6、22.6、27.7或32.7℃之人工氣候室處理，結果顯示參試品種之花下葉片數、定植到花芽創始、花苞可見和開花之天數，皆隨參試溫度上升逐漸減少。參試三品種自定植到花芽創始之基礎溫度為5.2-6.5℃，定植到花芽創始之積溫，依早中晚生品種分別為347.9、422.3和512.3℃d。另將參試品種置於均溫20.5℃及25.5℃、每日光照12 h之人工氣候室，以高壓鈉燈提供4.4、8.8、13.2或17.6 mol·m-2·d-1等光積值處理，結果顯示參試三品種於20.5℃處理之花下葉片數、到花苞可見與開花天數皆有因每日光積值提高而減少。於25.5℃處理提高光積值至13.2-17.6 mol·m-2·d-1之開花速率最快。於人工氣候室試驗整合溫度與光積值處理對開花天數之影響並建立預測開花時間模式，此模式經驗證可預測參試三品種於1-4月定植在溫室之花苞可見及開花時間。

Modelling the effects of daily light integral (DLI) and temperature on flower initiation and flower development in Eustoma can aid in planning production schedule. Plug seedlings of early-flowering‘Claris Pink’, mid-flowering‘Rin’, and late-flowering‘Ceremony Blue Flash’with 3-leaf pairs were planted in natural-lighted phytotrons (10.5-13.5 h daylength) with mean temperatures of 14.0, 17.6, 22.6, 27.7, or 32.7℃. Results showed that leaf number below the flower and time from planting to flower initiation, flower bud visibility and flowering decreased with temperature increased from 14.0 to 32.7℃. Base temperature for flower initiation was estimated as 5.2-6.5℃and thermal times required from planting to flower initiation were 347.9, 422.3, or 512.3℃d for‘Claris Pink’,‘Rin’, and‘Ceremony Blue Flash’, respectively. Seedlings were planted at mean temperatures of 20.5 or 25.5℃in phytotrons with 12 h photoperiod and DLI of 4.4, 8.8, 13.2, or 17.6 mol·m-2·d-1 provided by high pressure sodium lamps. Time to flowering decreased with increasing DLI in plants at 20.5℃, whereas the earliest flowering occurred in plants at 25.5℃with 13.2-17.6 mol·m-2·d-1 DLI. Modeling the effects of temperature and DLI were established for predicting days from planting to flower bud visibility and flowering. The constructed model from phytotron data was validated in plants planted from January to April in a greenhouse under varying temperature and light conditions.