Abstract: To cultivate high⁃quality commercial seedlings of Dendrobium fimbriatum，six different light quality treatments were set up，including 100% red light（R），100% blue light（B），80% red light+20% blue light（8R∶2B），70% red light+30% blue light（7R∶3B），and 50% red light+50% blue light（5R∶5B），with white fluorescent lamp as the control（CK）. After 60 days，growth indicators（plant height，leaf number，leaf length，stem diameter，fresh weight，dry weight），antioxidant indicators［superoxide dismutase（SOD）activity，malondialdehyde（MDA）content，ascorbate peroxidase（APX）activity，peroxidase（POD）activity，catalase（CAT）activity］，photosynthetic indicators（chlorophyll a content，chlorophyll b content，chlorophyll a+b content，chlorophyll a/b ratio，and carotenoid content），chlorophyll fluorescence indicators［potential activity of PS Ⅱ in plants（Fv/Fo），maximum photochemical efficiency（Fv/Fm），actual photochemical efficiency（Φ_PSⅡ），photochemical quenching coefficient（qP），electron transfer rate（ETR Ⅱ），and non⁃photochemical quenching coefficient（qN）］，as well as the content of nutrients（soluble proteins and soluble sugars）and other related indices，totaling 24 indexes were measured in order to screen the LED light quality ratio for the healthy growth of D. fimbriatum test⁃tube seedlings.The results indicated that monochromatic red light was beneficial for the height and elongation of test⁃tube seedlings，while monochromatic blue light was beneficial for increasing soluble protein content. 8R∶2B treatment was beneficial for leaf elongation，leaf number，and stem thickness increase of test⁃tube seedlings of D.fimbriatum.The overall antioxidant index was best when they were treated with 5R∶5B，and the dry and fresh weight，soluble sugar content，chlorophyll content，and chlorophyll fluorescence of test⁃tube seedlings were also best when they were treated with 5R∶5B.There was a significant correlation between growth indicators，antioxidant indicators，nutritional indicators，chlorophyll fluorescence parameters，and chlorophyll content.The results of principal component analysis indicated that the physiological and biochemical indicators of Dendrobium fimbriatum test⁃tube seedlings under 5R∶5B treatment showed the best performance，with the highest comprehensive score.In summary，the light environment of 50% red light+50% blue light（5R∶5B）LED is the most conducive to the growth and development of the test⁃tube seedlings of D.fimbriatum，and is the most suitable light environment for cultivating strong seedlings.

Key words: Dendrobium fimbriatum, LED, Light quality, Physiological characteristic, Chlorophyll fluorescence

摘要： 为培育流苏石斛优质商品苗，设置100%红光（R）、100%蓝光（B）、80%红光+20%蓝光（8R∶2B）、70%红光+30%蓝光（7R∶3B）、50%红光+50%蓝光（5R∶5B），以白色荧光灯为对照（CK）的6种不同光质处理照射流苏石斛试管苗，60 d后测定生长指标（株高、叶片数、叶长、茎粗、鲜质量、干质量）、抗氧化指标［超氧化物歧化酶（SOD）活性、丙二醛（MDA）含量、抗坏血酸过氧化物酶（APX）活性、过氧化物酶（POD）活性、过氧化氢酶（CAT）活性］、光合指标（叶绿素a含量、叶绿素b含量、叶绿素a+b含量和叶绿素a/b及类胡萝卜素含量）、叶绿素荧光指标［PSⅡ潜在活性（Fv/Fo）、最大光化学效率（Fv/Fm）、实际光量子效率（Φ_PSⅡ）、光化学淬灭系数（qP）、电子传递速率（ETRⅡ）及非光化学淬灭系数（qN）］及营养物质（可溶性蛋白和可溶性糖）含量等共24个指标，以期筛选出流苏石斛试管苗健壮生长的LED光质比。结果表明，单色红光有利于试管苗株高增加，单色蓝光利于可溶性蛋白含量增加。8R∶2B处理有利于流苏石斛试管苗叶片伸长、叶片数及茎粗增加，抗氧化指标整体上以5R∶5B处理最优，试管苗干鲜质量、可溶性糖含量和叶绿素含量及叶绿素荧光等整体上亦以5R∶5B处理最优。生长指标、抗氧化指标、营养指标、叶绿素荧光参数、叶绿素含量指标间存在显著相关关系。主成分分析结果表明，5R∶5B处理下流苏石斛试管苗生理生化指标表现最优，综合得分最高。综上，50%红光+50%蓝光（5R∶5B）LED光质环境最利于流苏石斛试管苗生长发育，是培育壮苗的最适宜光质比。

关键词: 流苏石斛, LED, 光质, 生理特性, 叶绿素荧光