人为扰动对乌拉尔甘草不同部位甘草酸与总黄酮含量的影响

人为扰动对甘草不同部位甘草酸含量和总黄酮含量均有较大的影响。即使是轻度的人为扰动 (土壤翻松 1次 )也会导致野生甘草的甘草酸含量明显下降 ,尤其对地下根茎 (兼有运输和储存功能 )中的甘草酸的积累影响最大。重度扰动栽培甘草各部位的甘草酸含量均较低 ,相对而言黄酮类物质的积累速率高于甘草酸 ,表明土壤扰动因素对甘草酸的形成与积累的影响大于总黄酮的形成与积累。无扰动野生甘草和轻度扰动野生甘草总黄酮含量从地上到地下呈下降趋势 ,而重度扰动栽培甘草的叶和不定根各有一个含量较高的部位 ,据此推断叶和不定根 (含毛状根 )是黄酮类物质的主要产生部位 ;具有输导功能的地上茎、复叶柄中总黄酮含量较低且波动较大。人为扰动对不同土壤深度甘草主根中甘草酸含量和甘草总黄酮含量的变化规律影响较小。无扰动野生甘草和轻度扰动野生甘草主根在 1.0～ 2 .0 m深度甘草酸含量分布较高是对该生境不同土壤深度长期适应的结果 ,而重度扰动栽培甘草主根可能尚未达到相应的土壤深度 ,因而表现为 1.0 m以下深层土壤中甘草酸含量较高。总之 ,旨在改善甘草生长条件的人为扰动对甘草酸和总黄酮的积累具有消极影响 ,适当的胁迫环境条件对提高药用植物的品质有益

Influences of artificial disturbance degrees on the contents of Glycyrrhizic acid and flavonoids in different parts of Glycyrrhiza uralensis

The external factors which influence the wild liquorice and the cultivated liquorice (Glycyrrhiza uralensis) in any habitat may be classified into two categories: natural factors and unartificial factors. For cultivated liquorice, some artificial factors such as soil deep tillage, irrigation or the other manipulations of field management should be made an appeal further. The contents of Glycyrrhizic acid and flavonoids were measured in different parts of Glycyrrhiza uralensis under different conditions of artificial disturbance by ultrasonic extraction, HPLC and spectrophotometry.The variable trends of the contents of Glycyrrhizic acid and flavonoids were studied in different habitats with different extent of artificial disturbance. The results showed that artificial disturbances are principal influencing factors on the content of Glycyrrhizic acid and flavonoids in different parts of liquorice. They obviously decrease the content of Glycyrrhizic acid in different parts of wild liquorice, even if light artificial disturbance (viz. once soil deep tillage) had been brought into effect. The accumulation of Glycyrrhizic acid in wild liquorice rhizomes (especially horizontal rhizomes which have main functions for substance transportation and accumulation) in the light disturbed habitat is lower than the in undisturbed habitat. The contents of Glycyrrhizic acid in different parts of heavy disturbed cultivated liquorice were also low. The research results showed that the accumulation velocity of flavonoids was higher than that of Glycyrrhizic acid, which indicated that soil disturbed factors acted on the production and accumulation of glycyrrhizic acid more than on flavonoids. The contents of flavonoids in different parts of undisturbed wild liquorice and light disturbed wild liquorice displayed descending trend from overground parts to underground parts, but that in the leaf and the coronal root of heavy disturbed cultivated liquorice were high. Based on these results, it can be deduced that the main producing parts of flavonoids are the leaves and the coronal roots. The content of flavonoids in terrestrial stem and stem of leaf which have any functions for substance transportation was low and presented major amplitude of fluctuation. At different soil depths, the content of glycyrrhizic acid in different liquorices taproot revealed obviously distinction but that of flavonoids was not obvious, which indicated that the artificial disturbance didn't act distinctly on the content variation of glycyrrhizic acid or flavonoids in different depths of liquorice taproot. The content of glycyrrhizic acid in undisturbed wild liquorice and light disturbed wild liquorce at soil depths from 1.0m to 2.0m was high, which should be the reason that wild liquorice has adapted to corresponding soil environments in which wild liquorice lives. For heavy disturbed cultivated liquorice, its taproot was not extend corresponding soil depths so that the content of glycyrrhizic acid in its taproot at the depth under 1.0m was high. In a word, the artificial disturbance which can improve any growing conditions of liquorice have negative effects on accumulation of glycyrrhizic acid and flavonoids of wild liquorice and cultivated liquorice. The appropriate stress environment can have profit to improve quality of medical plants.