溫度與光積值對洋桔梗生長與開花之影響模式

Modeling the effects of temperature and photosynthetic daily light integral on growth and flowering of Eustoma

陳慈華(Tzu-Hua Chen)

指導教授 ： 葉德銘

國立臺灣大學/生物資源暨農學院/園藝暨景觀學系/碩士(2013年)

https://doi.org/10.6342/NTU.2013.02168

摘要

洋桔梗[Eustoma grandiflorum (Raf.) Shinn.]為臺灣近年來重要的銷日切花作物。目前仍不完全清楚溫度與光對洋桔梗葉片分化、花芽創始及發育之影響模式，日本以15-20℃生長之花下葉片數和種植到開花天數為區分早中晚生品種之依據，是否可適用於臺灣地區，亦有待研究。
本研究取洋桔梗‘Claris Pink’、‘Rin’及‘Ceremony Blue Flash’涼溫培育穴盤苗，夏季(12.5-13.5 h自然日長)移至均溫14.0、17.6、22.6、27.7和32.7℃之自然光照室處理，其抽苔率皆達100%。三參試品種以22.6℃處理之葉片分化速率最快。三參試品種葉片分化之基礎溫度(base temperature)介於2.8-3.6℃，分化一片葉需26.3-31.3℃d 。三參試品種之花下葉片數及種植到花芽創始、可見花苞出現和開花天數隨參試溫度上升逐漸減少，品種間以晚生‘Ceremony Blue Flash’之花下葉片數及種植到花芽創始、可見花苞出現和開花天數明顯較‘Claris Pink’及‘Rin’為多。三參試品種自種植到花芽創始之基礎溫度為5.2-6.5℃，種植到花芽創始之溫度積值(thermal time)，依早中晚生品種分別為353.1、424.9和518.0℃d，品種間具顯著差異。三參試品種節間長度隨參試溫度增加而增加，莖徑、葉片厚度、花徑與開花時地上部乾重則隨之下降。秋植(11-12 h自然日長)情況下，‘Ceremony Blue Flash’於22.5℃之葉片分化速率最快，葉片分化之基礎溫度為4.8℃，而分化一片葉需45.5℃d。花下葉片數和從種植到花芽創始、可見花苞出現及開花天數隨參試溫度降低(32.5℃至14.0℃)而增加，從種植到花芽創始溫度積值為1199.2℃d。
在4月-9月(12.5-13.5 h自然日長下)，三參試品種種植於0%、65%、75%遮光之水牆溫室內，以未遮光處理之葉片分化速率最快，隨遮光程度增加葉片分化速率有逐漸下降之趨勢。隨著處理光積值增加，三參試品種之第一可見花苞下葉片數減少，從種植到花芽創始和到可見花苞出現天數亦縮短。種植於65%及75%遮光者發生花苞消蕾(blasting)或延遲開花，開花時株高較未遮光處理者高。洋桔梗‘Claris Pink’和‘Rin’之節間長度於遮光處理間無顯著差異，而‘Ceremony Blue Flash’節間長度則隨遮光程度增加而增長。
三參試品種種植於23/18℃、每日光照12 h之人工光照室，以高壓鈉燈提供光積值4.4、8.8、13.2及17.6 mol•m-2•d-1等處理。結果顯示三參試品種以光積值17.6 mol•m-2•d-1處理之葉片分化速率最快，且花下葉片數隨光積值增加而減少。晚生‘Ceremony Blue Flash’之花下葉片數較‘Claris Pink’及‘Rin’為多，在低光積值4.4-8.8 mol•m-2•d-1下，品種間之花下葉片數差距明顯。三參試品種從種植到花芽創始、可見花苞出現及到開花天數均隨光積值增加而縮短。三參試品種皆以低光積值4.4 mol•m-2•d-1處理之株高最高，節間長度亦較長。
三參試品種冬季種植於水牆溫室(18.7-24.3℃)，進行不同光照處理，計有每日9 h自然日照(ND)、9 h自然日照+5 h 高壓鈉燈補光(ND with HID)、9 h自然日照+5 h鎢絲燈延長日照(ND+ I DE)、9 h自然日照+5 h高壓鈉燈延長日照(ND+ HID DE)及9 h自然日照+鎢絲燈暗期中斷(ND+ NI)等5處理。三參試品種於延長日照及暗期中斷等長日處理之花下葉片數較少，且從種植到可見花苞出現和到開花天數較短，而補光等提高光照亦能使洋桔梗花芽創始提早。三參試品種均以ND+ HID DE處理較早開花、植株高度較矮，且葉片較厚，而以ND+ I NI和ND+ I DE處理之節間長度較長，且具較多的花苞數，莖徑則以提高光照者較粗，花徑和花瓣數均以ND+ HID DE處理者較大、較多。
三參試品種分別種植於平均溫度20.5和25.5℃搭配光積值4.4、8.8、13.2及17.6 mol•m-2•d-1環境，共計8處理，計算求得花下葉片數、種植到可見花苞出現及開花天數之模式，與每隔兩週定植於塑膠溫室自然環境者進行驗證，結果顯示於臺灣自然日照11-13.5 h環境中，以溫度和光積值建立之模式能準確預測三參試品種之花下葉片數、種植到可見花苞出現及開花天數。

關鍵字

種植到開花天數 ； 葉片分化 ； 花下葉片數 ； 相對長日植物 ； 溫度積值

並列摘要

Lisianthus [Eustoma grandiflorum (Raf.) Shinn.] is an important cut flower crop in Taiwan for exportation to Japan. Modeling the effects of daily light integral and temperature on leaf initiation, flower initiation, and flower development of Eustoma is presently limited. Japanese growers define early- and late-flowering cultivars based on leaf number below the flower and days to flowering by growing plants at 15-20oC. However, it is required to determine whether this definition could be directly adapted to the growing conditions in Taiwan.
Plug seedlings of Eustoma ‘Claris Pink’, ‘Rin’, and ‘Ceremony Blue Flash’ were planted in phytotrons with mean temperatures of 14.0, 17.6, 22.6, 27.7, and 32.7oC in summer under 12.5-13.5 h natural daylengths. All plants bolted at 3 weeks after treatments. Optimum temperature for leaf initiation was 22.6oC for the three cultivars. Base temperature for leaf initiation was estimated to be 2.8-3.6oC, and thermal time of 26.3-31.3oCd was required for each leaf initiation. Leaf number below the flower and time from planting to flower initiation, flower bud visibility, and flowering decreased with increasing temperature from 14.0 to 32.7oC. Late-flowering ‘Ceremony Blue Flash’ had more leaf number below the flower and longer time to floral development than ‘Claris Pink’ and ‘Rin’. Base temperature for flower initiation was estimated as 5.2-6.5oC and thermal times required from planting to flower initiation were 353.1, 424.9, and 518.0oCd for ‘Claris Pink’, ‘Rin’, and ‘Ceremony Blue Flash’, respectively. Internode increased and stem diameter, leaf thickness, flower diameter, and shoot dry weight decreased with increasing temperature.
Optimum temperature for leaf initiation was estimated as 22.5oC for ‘Ceremony Blue Flash’ planted in autumn under 11-12 h natural daylengths. Base temperature for leaf initiation was 4.8oC and 45.5oCd was required for each leaf initiation. Leaf number below the flower, time from planting to flower initiation, flower bud visibility, and flowering increased with decreasing temperature from 32.5 to 14.0oC. Thermal time from planting to flower initiation was 1199.2oCd. Plug seedlings of the three Eustoma cultivars were planted in a pad and fan house with 0%, 65%, and 75% shading level. Leaf initiation rate was fastest in plants grown without shading, and decreased with increasing shading level. Leaf number below the first visible flower bud, time from planting to flower initiation and flower bud visibility increased with more shading. Delayed flowering or flower blasting was observed in plants grown under 65% and 75% shading. Plants grown under 65% and 75% shading were longer than those without shading. Shading did not affect internode of ‘Claris Pink’ and ‘Rin’, whereas internode of ‘Ceremony Blue Flash’ increased with increasing shading level.
Seedlings of the three cultivars were planted at 23/18oC in an artificial lighting room with 12 h photoperiod under 4.4, 8.8, 13.2, and 17.6 mol•m-2•d-1 daily light integral (DLI). Plants grown under 17.6 mol•m-2•d-1 had the highest leaf initiation rate. Leaf number below the flower decreased with increasing DLI. Late-flowering ‘Ceremony Blue Flash’ had more leaf number below the flower than ‘Claris Pink’ and ‘Rin’. Cultivar difference in leaf number below the flower was more obvious in plants under low DLI (4.4-8.8 mol•m-2•d-1) conditions. Time from planting to flower initiation, flower bud visibility, and flowering decreased with increasing DLI. Plant height and internode were higher and leaf was thinner in plants grown under 4.4 mol•m-2•d-1.
Seedlings of the three cultivars were planted under 9 h daylength (ND), 9 h ND + 5 h high-intensity discharge (HID) supplement lighting (ND with HID), 9h ND + 5 h incandescent light (I) bulb for day extension (DE) (ND + I DE), 9 h ND + 5 h HID for DE (ND + HID DE), and 9 h ND + 5 h I for night interruption (NI) (ND + I NI) in a pad and fan house. Fewer leaf number below the flower and shorter time from planting to flower bud visibility and flowering were recorded in plants grown under long day conditions. Earlier flower initiation and wider stem diameter were found in those grown under higher DLI. Plants were shorter and leaves were thicker when grown under ND + HID DE. ND + I NI and ND + I DE treatments resulted in longer internode and more flower buds. Branch number did not differ between these lighting treatments. Flower diameter and petal number were higher in plants grown under ND + HID DE.
Seedlings of the three cultivars were planted in an artificial room at 20.5 and 25.5 oC in combination with four daily light integrals of 4.4, 8.8, 13.2, and 17.6 mol•m-2•d-1. Modeling the effects of temperature and daily light integral were established for predicting leaf number below the flower, days from planting to flower bud visibility and flowering. The models were validated with sowing the seeds every two weeks and seedlings grown in a plastic greenhouse under 11.0-13.5 h daylengths in Taiwan.

並列關鍵字

days from planting to flowering ； leaf initiation ； leaf number below the flower ； quantitative long-day plant ； thermal time

參考文獻

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