LED光環境控制系統之建立與其應用於星辰花組培苗生理影響之探討

Abstract

發光二極體( Light-Emitting Diode, LED )近年來逐漸被廣泛的運用，其中之一為提供植物組織培養之人工栽培光源，主要因為其具有較高的光電轉換效率、熱產生較一般日光燈管低與波長特定等優點。本研究使用紅、藍光兩種 LED 開發一套應用於組織培養上之光環境控制系統，並利用 LabVIEW 軟體自行開發光源模擬與控制程式進行操作。陣列式紅、藍光 LED 模組可設定多樣性之顯示來改變光質特性，且透過獨自改變紅、藍光 LED 之光強度可控制整體光源之光質與光度特性，最後以光週期控制程式進行栽培期間內時間之監控，達到具有彈性調控光源之光質、光度與光週等功能。於光源中心正下方 10 cm 處，純紅光與純藍光 LED 模組可提供約 150 μmol m-2 s-1 之光強度，而紅、藍光 LED 混合模組則提供約 80 μmol m-2 s-1 紅光與約 50 μmol m-2 s-1藍光之光強度。 利用上述之光環境控制系統製造出純紅光、純藍光、紅藍比1：2與2：1等四種光質特性之光環境，控制總光度各約為 100μmol m-2 s-1 (離樣本之高度為 5 cm )，於星辰花組培苗栽培試驗及出瓶後馴化，並以傳統日光燈管光源栽培作為差異比較。結果顯示：光質主要影響葉片之型態與功能，純藍光下生長之葉片較細長、葉色較青與葉綠素含量較低等，隨紅光比例的增加，所生長之葉片愈接近於日光燈管下之葉片；五種處理作物均能生長與分化，於乾物累積上無顯著差異。出瓶馴化階段各處理樣本在日光燈管光源下各差異均能恢復至正常範圍，顯示LED人工光源可應用於組織培養上並可探討光質對植物葉片型態之影響。

Light-Emitting Diodes (LED) are widely used every walk of life recently such as artificial light for plants. There are many advantages like specified wavelength, higher electric-light transformation performance and lower heat generation. The study is aimed to develop a light environment control system (LECS) using red and blue light LED’s as a light source. A light simulation and control program was developed to integrate and control the LECS system using LabVIEW software. Using the program, the LED-array can be arranged at random to define different aspects of light quality. Individual setting the light intensity of red and blue LED’s can also change the light quality and intensity simultaneously. The program can monitor the control photoperiods when applying to plant cultivation. Therefore, light quality, light intensity and photoperiod can be controlled flexibly when LECS system is used. The red LED module and blue LED module can individually provide a light intensity of 150 mmol m-2 s-1, and the red/blue LED mixed module can provide about 80 mmol m-2 s-1 for red light, and about 50 mmol m-2 s-1 for blue light at 10 cm height. Using the developed LECS system, four settings of light quality (pure red light, pure blue light, R/B ratio = 1:2 and R/B ratio = 2:1) were applied to tissue culture experiments of Limonium. The results show that: leaves developed under pure blue light become thiner, whiter and lower in chlorophyll content. When the proportion of red light is increasing, leaves are more close to those developed under tube fluorescent light. There is no significant difference in wet and dry weight among all the treatments. All the samples can be recovered to a normal growth when tube fluorescent light is provided during ex vitro acclimatization. The light environment control system developed in this study has potential applications to tissue culture production and the study of light quality effects on morphogenesis and physiology of plants.