中文摘要：

目的：探讨不同浓度的钼营养水平对甘草幼苗生长、生物量和抗氧化酶活性及药材质量的影响。方法：在温室中对水培甘草幼苗进行4个不同钼营养水平（0．55，1．1，5．5，11．0mg·L^-1）处理，另设0mg·L^-1为对照组（CK），测定甘草幼苗各器官生物量，超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性，以及甘草苷和甘草酸的含量。结果：在钼浓度为5．5mg·L^-1时甘草幼苗的根干、鲜重和根冠比最大，并且此时甘草根、茎和叶中的SOD、POD和CAT3种抗氧化酶的活性最高，表明该浓度较适合甘草幼苗的生长和根干物质的积累，低钼水平或高钼水平都不利于甘草幼苗的生长。然而，1．1mg·L^-1对甘草根中甘草酸的积累有显著的促进作用，CK处理的甘草酸含量最低。结论：适宜的钼浓度对甘草幼苗根干物质和有效成分的积累很重要，并且抗氧化酶活性可以反应甘草幼苗对钼的适应性。因此，需要进一步探寻介于1．1～5．5mg·L^-1、同时满足既能增加甘草根干物质的积累又能提高甘草酸的含量的钼值。

英文摘要：

Objective： To investigate the effects of different molybdenum （Mo） concentrations on growth, biomass, the activities of antioxidase and quality of Glycyrrhiza uralensis. Methods： The seedlings of G. uralensis were subjected to four concentrations Mo treatments （0. 55, 1.1, 5.5, 1 I. 0 mg·L^-1 Mo） by water culture in a greenhouse. The concentration of Mo in control block （CK） is 0 mg·L^-1. The biomass, activities of superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） and the contents of glycyrrhizic acid and liquiritin of seedlings were determined. Results： The results indicate that under 5.5 mg·L^-1 Mo treatment, the fresh and dry weight, and the root shoot ratio are the highest, and the activities of SOD, POD and CAT of the root, stem and leaf in G. uralensis are also the highest. It indicates the concentration of Mo was appropriate for growth and accumulation of root, and low concentration of Mo or high Mo were not good for the growth of this plant. However, the accumulation of glycyrrhizic acid of the root was significantly improved by the concentration of 1.1 mg·L^-1 Mo. In addition, the content of glycyrrhizic acid under CK reached lowest. Conclusion： The results demonstrate that proper Mo concentration can significantly enhance biomass and active constituents of the root, and the activities of antioxidase could response the adaptability of G. uralensis seedlings to molybdenum. Therefore, a further experiment will be done to find a suitable concentration of Mo that could no only increase the root biomass but also increase contents of glycyrrhizic acid.