- 學位論文
綠光強度對甜薰衣草生長及保健功效之探討
The Effects of Green Light Intensity on Growth and Functional Properties of Lavandula heterophylla
摘要
光線是植物生長的重要因子,除了作為光合作用能量來源,也作為誘發光形態發生的訊號。過去已有許多紅、藍光對植物生長發育之研究,綠光的研究相對缺乏,也尚未有文獻針對不同強度之綠光與照射時間做探討。甜薰衣草(Lavandula heterophylla)為唇形科植物,其精油具有高經濟價值,傳統民間藥用可治療頭痛、糖尿病、憂鬱症等,現今研究大多分析其內含之植化素,較少有針對不同栽培技術的角度來作生長與生理方面之探討。本研究利用發光二極體(Light Emitting Diode, LED)為光源,維持紅、藍光強度在 40 μmol m-2 s-1,設定綠光強度為 0、20、40 與 60 μmol m-2 s-1,分別處理 2 週和 4 週,探討添加綠光對甜薰衣草生長、形態和生理之影響,並檢測植化素含量的變化,分析保健功效。結果顯示,添加綠光可促進生物質量的累積,也可觀察到葉角度在高強度綠光處理下達到最小,顯示高強度綠光能誘發避蔭性狀。在葉綠素螢光參數上,添加綠光使 qP、ETR、φPSII上升,表示可提升光合效能。此外,光合色素和二次代謝物含量也明顯變動,高強度綠光會降低葉綠素、類胡蘿蔔素、花青素和類黃酮含量,卻促進酚類之生成。在保健功效方面,添加高強度綠光能提升植株萃取液之抗氧化能力,在抑制黃嘌呤氧化酶能力上則差異不大。透過關聯性分析,得知保健功效的提升有一部分來自酚類的貢獻,而植株體內是否含有其他保健物質則有待進一步釐清。綜合以上結果,作物栽培時利用 LED 照明技術添加綠光,有助於作物生長、增加植化素含量及提升保健功效,進而增加作物之附加價值。由本研究結果也顯示甜薰衣草為具有潛力之藥用作物,針對其保健成分可作深入分析,供未來醫學保健研究之參考。
並列摘要
Light is one of the most important factors on plant growth. It provides not only energy for photosynthesis but also information for photomorphogenesis. There has been intensive researches on the effects of red and blue light on plants growth and development, however much less is known about the specific effects of green light. There is little investigation on the effects of green light intensity and irradiation time on plants. Sweet lavender (Lavandula heterophylla) belongs to the Lamiaceae family. Its essential oil is provided with high economic value. It’s also widely used in traditional folk therapy for remedying headaches, diabetes, depression, etc. Most of today's studies are focused on sweet lavender’s phytochemicals; few are viewed from the cultivation and management techniques to evaluate its growth and physiological responses. The objective of this study is to investigate the effects of green light on the growth and functional properties of sweet lavender for 2 and 4 weeks by using light emitting diode (LED) for illumination. Experiments were performed in growth chamber and light treatment was fixed red and blue light (40 μmol m-2 s-1) with different intensities of green light (0, 20, 40 and 60 μmol m-2 s-1). The results revealed that the additional green light could improve the biomass. In addition, the leaf angel was the smallest in highest intensity green light treatment, which suggested that green light could induce shade avoidance symptom. In the aspects of chlorophyll fluorescence parameters, qP, ETR and φPSII increased when green light was added. It showed that additional green light could promote the photosynthetic potential. Besides, it could also modulate the content of photosynthetic pigments and secondary metabolites. High intensity green light inhibited the synthesis of chlorophyll, carotenoid, anthocyanin and flavonoid but induced phenolic. In functional properties analysis, supplementation of higher intensity green light promoted antioxidant activities, but made no difference in xanthine oxidase inhibition activity. The correlation between phytochemicals and functional properties indicated that phenolic contributed to the antioxidant activities, but aside from phenolics, there should be other functional compounds needed to be confirmed. In conclusion, supplementation of green light can promote the growth and raise the functional properties by inducing the phytochemicals, which can enhance the value of sweet lavender. This study also shows that sweet lavender is a potential medicinal crop and its high functional properties are good for further research.