Abstract: Dimocarpus longan(Lour.) is rich in flavonoids and other secondary metabolites, and has important nutritional and medicinal values. Light quality could regulate flavonoids in the longan embryonic callus(ECs). However,the effect of red and blue composit light on the longan ECs has not been reported.Therefore,the effects of different red-blue composite light ratio on the growth status and flavonoid metabolites content of longan ECs were investigated,and the expression profiles of DlCHS,DlLAR and DlHY5 were analyzed.The results showed that the growth rates of longan ECs were highest under the light condition(red∶blue=1∶9,2∶8),up to 1 107.50% and 1 130.0%,respectively.The contents of total flavonoids and epicatechin reached the highest value under the light condition(red∶blue=1∶9),up to 12.49 mg/g and 2 187.54 μg/g,respectively.When the red-blue composite light ratio was 5∶5 and 3∶7,the DlCHS and DlLAR gene expression levels were the highest,while the DlHY5 expression level was the highest when the red-blue composite light ratio was 1∶9.The red-blue composite light was beneficial to the synthesis of flavonoids and epicatechin in longan ECs,and the synthesis of secondary metabolites were improved with the increase of the ratio of blue light.

Key words: Dimocarpus longan, Embryogenic callus, Red-blue composite light, Flavonoid metabolism, Gene expression

摘要： 为探究红蓝复合光对龙眼胚性愈伤组织生长影响及对类黄酮代谢的调控机制，以龙眼胚性愈伤组织为试材，研究红蓝复合光配比对其生长、总黄酮和表儿茶素含量的影响，结合qPCR技术分析类黄酮合成相关酶基因DlCHS、DlLAR和编码光信号转录因子DlHY5基因的表达变化。结果表明，龙眼胚性愈伤组织在红蓝复合光配比为1∶9和2∶8时生长率较高，分别为1 107.50%、1 130.0%，生长状态也较好；红蓝复合光配比为1∶9，类黄酮含量和表儿茶素含量最高，分别为12.49 mg/g和 2 187.54 μg/g；当红蓝复合光配比为5∶5和3∶7时，DlCHS和DlLAR基因表达量较高，而DlHY5的表达量在红∶蓝=1∶9时达到最高值。红蓝复合光有利于龙眼胚性愈伤组织中类黄酮及表儿茶素合成，且蓝光比例越大越有利于次生代谢物质的合成。

关键词: 龙眼, 胚性愈伤组织, 红蓝复合光, 类黄酮代谢, 基因表达