光質與光強度對白鶴芋之光合作用與甲醛移除效率之影響

Effects of Light Quality and Intensity on Photosynthesis and Formaldehyde Removal Efficiency in Peace Lily

白鶴芋為室內常見的觀賞植物且已知可移除致癌物甲醛，本研究取白鶴芋‘帕拉斯’盆栽，以不同藍紅比例光質（藍光比例0%、9%、16%、43%、88%、100%）之發光二極體(light-emitting diode, LED)為光源，在株高處提供60μmol·m-2·s-1光強度處理4個月。結果顯示植株於無藍光處理者（純紅光）其氣孔導度及蒸散作用速率最低，以43%藍光：57%紅光處理之淨光合作用速率最高。植株在純藍光、純紅光、白光（紅：藍：綠光質比為19：29：52）LED燈及T5螢光燈（紅：藍：綠光質比約為37：39：24）四種光源提供150μmol·m-2·s-1光強度環境下，皆可移除密閉熏氣箱內木心板所釋放之甲醛，但以藍光、白光LED燈及T5螢光燈處理者之甲醛移除量較多，而紅光LED燈處理者移除甲醛量較少。將植株置於初始甲醛濃度約為1.0μL·L-1之熏氣箱，以螢光燈及高壓鈉燈為光源提供株高處0、40、80、120或160μmol·m-2·s-1光強度處理3小時。結果顯示植株於黑暗下仍可移除少量甲醛，而提高光強度使甲醛移除效率、淨光合作用速率與氣孔導度增加。單位葉面積之甲醛移除量與淨光合作用速率和氣孔導度呈正相關。

Peace lily (Spathiphyllum kochii Engl. et Krause) are commonly used for indoor decoration and have been known to remove formaldehyde, a human carcinogen. In this study, plants of peace lily‘Palas’were placed under various blue and red ratios (blue light 0%, 9%, 16%, 43%, 88%, or 100%) provided from light-emitting diodes (LED) at 60μmol·m-2·s-1 for four months. Results showed that plants under 0% blue (pure red) LED lighting had the lowest stomatal conductance and transpiration rate, whereas those under 43% blue : 57% red LED had the highest net photosynthetic rate. Plants were placed under 100% blue, 100% red, white (19 red: 29 blue: 52 green) LED lighting, and T5 fluorescent lamps (37 red: 29 blue: 24 green) at 150μmol·m-2·s-1 in air-tight chambers, together with one lumber core plywood block which released formaldehyde. Results showed plants under 100% red LED reduced less formaldehyde released from the plywood than those under other lighting sources tested. Plants were placed in chambers with an initial 1.0μL·L-1 formaldehyde for 3 hours under 0, 40, 80, 120, and 160μmol·m-2·s-1 provided from cool white fluorescent and high pressure sodium lamps. Results showed plants could reduce small amounts of formaldehyde in dark conditions. Formaldehyde removal, net photosynthetic rate, and stomatal conductance increased with increasing light intensity. Formaldehyde removal on a unit leaf area base is positively correlated to net photosynthetic rate and stomatal conductance.