光强对菘蓝生长、化学成分及抗氧化活性的影响

  目的  探究光强对大青叶基原植物菘蓝Isatis indigotica生长、药材大青叶化学成分及抗氧化活性的影响，为大青叶基原植物菘蓝的人工栽培提供参考。  方法  在100%全光照、60%全光照、20%全光照下种植菘蓝，观测菘蓝生长旺盛期叶片生长情况，同时测定大青叶靛蓝、靛玉红、总黄酮、总多糖、总游离氨基酸等化学成分质量分数和抗氧化活性。  结果  菘蓝叶片生长与光强呈正相关，100%全光照组的菘蓝株高、叶长、叶宽、叶片数、叶面积均为最高；大青叶靛蓝、总黄酮、总多糖质量分数均随着光强的降低而降低，且各组间差异显著(P＜0.05)；靛玉红质量分数随光强的增加呈先升高后降低的趋势，60%全光照组显著高于其他处理(P＜0.05)，但100%全光照组与20%全光照组间差异不显著；总游离氨基酸质量分数随着光强的降低而升高。抗氧化活性与光强呈正相关，20%全光照组的1,1-二苯基-2-三硝基苯肼(DPPH)自由基半清除率(I_C50)显著高于60%全光照组和100%全光照组(P＜0.05)。  结论  100%全光照下大青叶药材产量最高，且内在品质最好，较60%和20%全光照更适合栽培。表8参39

Effects of light intensity on growth,chemical composition and antioxidant activity of Isatis indigotica

  Objective  The present study, with an exploration of the effects of light intensity on growth of Isatis indigotica, and chemical composition, antioxidant activity of isatidis folium, aims to provide reference for the artificial cultivation of I. indigotica.   Method  With seedlings of I. indigotica planted under 100%, 60% and 20% of full sunlight, their growth indexes were measured at the vigorous growth period, whereas chemical compounds such as indigo, indirubin, total flavonoids, total polysaccharides and total free amino acid, as well as antioxidant activity were determined after harvest.   Result  The growth of leaves was positively correlated with the light intensity, and the plant height, leaf length, leaf width, number of leaves, and the single leaf area in 100% of full sunlight treatment were the largest. Indigo, total flavonoids and total polysaccharides of isatidis folium were decreased with the decrease of light intensity, and there were significant differences among three groups (P＜0.05). Indirubin showed a trend of increasing first and then decreasing, with that of the 60% of full sunlight treatment being the highest (P＜0.05), yet no significant differences between the ones of 100% and 20% of full sunlight treatment. The total free amino acid was negatively correlated with light intensity and increased with the decrease of light intensity. The antioxidant activity was positively correlated with the light intensity and the I_C50 (half maximal inhibitory concentration) for DPPH of 20% of full sunlight treatment was significantly higher than that in 60% and 100% of full sunlight treatment (P＜0.05).   Conclusion  The 100% of full sunlight treatment was the optimum light intensity condition to achieve high yield and intrinsic quality of isatidis folium, which is more conducive to the cultivation of isatidis folium than the 60% and 20% full sunlight treatment. Ch, 8 tab. 39 ref.]