不同光质对甘草苗期生长及活性成分含量的影响

Light Quality Affects Growth and Active Component Content of Glycyrrhiza uralensis Seedlings

目的:探究不同光质对甘草苗期生长及活性成分积累的影响特征。方法:采用白光(对照)、红光、蓝光、红蓝光(红光∶蓝光=2∶1)和蓝红光(蓝光∶红光=2∶1)5种光质处理甘草,分别在光质处理36、106 d测定甘草的生长指标,建立甘草根部12个活性成分含量的测定方法,结合聚类分析探析不同光质对甘草活性成分积累的影响特征。结果:红光促进甘草株高增长的作用较其他光质大,红光下甘草株高比对照高40.9%~45.1%;红蓝光促进甘草根部生长的作用明显,不同光质下甘草根长、根粗和根干质量增长量变化趋势一致,均为红蓝光>红光>白光>蓝红光>蓝光;不同光质处理106 d甘草的根冠比均大于处理36 d,红蓝光处理106 d甘草的根冠比最大,是对照的2.8倍。聚类分析结果表明,甘草的活性成分随不同光质处理时间的延长而增大,不同光质下甘草酸、芹糖异甘草苷、异甘草苷等9个活性成分含量随不同光质处理时间的增加呈升高趋势。红蓝光促进甘草中甘草酸、芹糖异甘草苷、异甘草苷、异甘草素、新异甘草苷、甘草素和甘草苷积累的作用较其他光质大,分别比对照高88.24%、17.39%、284.31%、156.95%、246.35%、89.06%和207.40%;蓝红光促进甘草中甘草苷、甘草素、甘草酸和异甘草素积累的作用较大,分别比对照高12.42%、3.00%、7.07%和5.41%;增加蓝光比例有利于甘草中甘草查耳酮A的积累,红光处理36 d促进山柰酚和刺甘草查耳酮的积累,处理106 d抑制以上2个成分的积累。结论:红光对甘草地上部生长有较强促进作用,红蓝光可以显著促进甘草根系的生长和生物量积累;红光和蓝光混合光质较红光或蓝光单色光质对甘草中多种活性成分积累的促进作用更大,以红蓝光处理更佳,红蓝光与甘草中异甘草素、甘草素和甘草苷的积累呈正相关。为光质在甘草次生代谢成分的定向培育应用提供参考。

Objective:To explore the effects of different light qualities on the growth and active component accumulation of Glycyrrhiza uralensis seedlings.Methods:The seedlings of G.uralensis were treated with white light(W,control),red light(R),blue light(B),red-blue light(R∶B=2∶1),and blue-red light(B∶R=2∶1),respectively.The growth indexes of G.uralensis were determined after 36 days and 106 days,respectively.A method for determining multiple components in G.uralensis was established.Cluster analysis was employed to analyze the effects of different light qualities on the accumulation of active components in G.uralensis.Results:Red light had stronger effect on the plant height of G.uralensis than other light qualities,and the plant height of G.uralensis exposed to red light was 40.9%-45.1%higher than that of the control.Red-blue light significantly promoted the root growth.The root length,root diameter,and dry root weight of G.uralensis exposed to different light qualities followed the same trend of red-blue light>red light>white light>blue-red light>blue light.The root-to-shoot ratio of G.uralensis treated for 106 days was higher than that treated for 36 days.Particularly,the root-to-shoot ratio of G.uralensis exposed to red-blue light for 106 days was 2.8 times that of the control.The results of cluster analysis showed that the differences in active component content between different light treatments increased with the extension of treatment time.The content of the other nine active components except echinatin,kaempferol,and licochalcone A in G.uralensis increased with the extension of treatment time.Red-blue light showed the strongest promoting effect on the accumulation of glycyrrhizic acid,isoliquiritin apioside,isoliquiritin,isoliquiritigenin,neoisoliquiritigenin,liquiritigenin,and liquiritin in G.uralensis,which were 88.24%,17.39%,284.31%,156.95%,246.35%,89.06%,and 207.40%higher than that of the control,respectively.Blue-red light promoted the accumulation of liquiritin,liquiritigenin,glycyrrhizic acid,and isoliquiritigenin,which were 12.42%,3.00%,7.07%,and 5.41%higher than that of the control,respectively.Increasing the proportion of blue light was beneficial to the accumulation of licochalcone A in G.uralensis.Red light treatment for 36 days promoted the accumulation of kaempferol and echinatin,while that for 106 days inhibited the accumulation of the above two components.Conclusion:Red light had a strong promoting effect on the growth of the aboveground part of G.uralensis.Red-blue light can significantly promote the growth and biomass accumulation of G.uralensis root.The mixtures of red light and blue light,especially red-blue light,had greater effect on the accumulation of active components in G.uralensis than red light or blue light alone.Red-blue light had a positive correlation with the accumulation of isoliquiritigenin,liquiritigenin,and liquiritin.The findings of this study provide a reference for the application of different light qualities in the directed cultivation of G.uralensis for the accumulation of secondary metabolites.