不同红蓝LED组合光源对叶用莴苣光合特性和品质的影响及节能评价

Influence of Combined Lighting with Different Red and Blue LED on Photosynthetic Characteristics and Quality of Lettuce and Evaluation of Energy Consumption

为了探求适合叶用莴苣生长的节能高效的光源参数,采用红、蓝光波峰组合分别为红光(R)660nm+蓝光(B)450nm的LEDA型和红光(R)630nm+蓝光(B)460nm的LEDB型光源,每种光源设置R/B分别为6、8和10的3种比例,处理叶用莴苣。结果表明:LEDA型与LEDB型光源处理的叶用莴苣光合速率、蒸腾速率、气孔导度、胞间CO2浓度、维生素C、总糖和硝酸盐含量均无显著差异,但均较荧光灯光源(对照)显著提高了光合速率。两种光源不同R/B处理的上述指标变化趋势一致,均表现为R/B=8时(LEDA2、LEDB2)最优,其中LEDA2处理比荧光灯处理光合速率提高38%,维生素C含量增加8.3%,硝酸盐含量降低9.2%;LEDB2处理时光合速率提高48%,硝酸盐含量降低6.5%。LEDA型光源处理的叶绿素a、b和(a+b)含量显著高于LEDB型光源处理,且分别表现为LEDA3和LEDB2处理的含量最高。此外,对光源装置耗电量的计算表明,LEDB型光源的单株耗电量比LEDA型和荧光灯(对照)分别节省53.3%和27.7%。因此,红、蓝光波峰分别为630nm+460nm的组合LED光源,R/B=8的条件下,在提高叶用莴苣光合速率和品质以及降低耗电量3个方面体现优势。

To research the energy-saving and high-efficiency lighting parameters suitable for lettuce growth,LEDA and LEDB lighting were used.LEDA lighting was composed of red with peak at 660 nm（R）and blue with peak at 450 nm（B）,LEDB lighting was composed of red with peak at 630 nm（R）and blue with peak at 460 nm（B）.Treatments with R/B ratio of 6,8,10 were performed with LEDA and LEDB respectively.Results showed that photosynthetic rate of lettuce was significantly higher under LED lighting than under fluorescent lamp.There were no significant differences in photosynthetic rate,transpiration rate,stomatal conductance,intercellular CO2 concentration,vitamin C,total sugar and nitrate content of lettuce between LEDA and LEDB.All those indices showed the same change trend with R/B,and they were the best at the R/B ratio of 8（LEDA2,LEDB2）.Compared with fluorescent treatment,photosynthetic rate and vitamin C content increased 38% and 8.3% respectively,while nitrate content decreased 9.2% in LEDA2 treatment,and photosynthetic rate increased 48% and nitrate content decreased 6.5% in LEDB2 treatment.The content of chlorophyll a,b and（a ＋ b）were significant higher under LEDA lighting than under LEDB lighting,and were the highest under LEDA3 and LEDB2 treatments,respectively.In addition,results of power consumption of lighting device showed,compared with LEDA lighting and fluorescent,the power consumption per plant of LEDB lighting decreased 53.3% and 27.2%,respectively.Thus,LED lighting composed of red with peak at 630 nm and blue with peak at 460 nm,while R/B = 8,not only could improve photosynthesis rate and quality,but also is more energy-saving than other treatments.The aim of efficient and energy-saving was achieved from above three aspects.