目的研究5种化感物质对人参根系酶活性的影响, 探讨化感物质对根系保护性酶活性的作用规律。方法采用营养液培养方法, 研究了苯甲酸、邻苯二甲酸二异丁酯、丁二酸二异丁酯、棕榈酸和, 2-2二(4-羟基苯基)丙烷对苗期人参根系过氧化物酶(POD)、过氧化氢酶(CAT)和苯丙氨酸解氨酶(PAL)酶活性的影响。结果苯甲酸在种3浓度下均抑制人参幼苗根系POD酶活性, 邻苯二甲酸二异丁酯和丁二酸二异丁酯仅在低浓度时抑制POD酶活性, 棕榈酸和, 2-2二(4-羟基苯基)丙烷3种浓度下均促进POD酶活性, 且与化感物质浓度呈正相关。除丁二酸二异丁酯和棕榈酸外, 其余3种化感物质均表现为处理浓度与CAT酶活性正相关, 且与对照相比, 化感物质对CAT酶活性的影响均表现促进作用。苯甲酸和丁二酸二异丁酯在低浓度时抑制PAL酶活性, 中浓度处理对PAL酶活性的促进作用大于高浓度处理;棕榈酸在低浓度时对PAL酶活性的促进作用最强, 2-2二(4-羟基苯基)丙烷在高浓度时对PAL酶活性的促进作用最强, 邻苯二甲酸二异丁酯对PAL酶活性的促进作用与浓度呈正相关。研究还发现, 对照及5种化感物质处理中的POD、CAT、PAL酶活性均随处理时间延长而变化, 但酶活性与处理时间无明显相关性。结论人参根系分泌物中5种化感物质对人参根系POD、CAT和PAL酶活性有显著影响。

Objective To analyze the genetic diversity of Radix Bupleuri using two different molecule markers for distinguishing cultivars in Bupleurum L.and Radix Bupleuri.Methods Random amplified polymorphic DNA(RAPD) and amplified fragment length polymorphism(AFLP) molecular markers were used for distinguishing cultivars in Bupleurum L.and Radix Bupleuri.Results It showed that a total of 28 lines were amplified from nine cultivars in Bupleurum L.using three kinds of primers selected in RAPD analysis,and the average for each primer amplified with 9.33,6.67(71.43%) of them were polymorphic.In AFLP analysis,four primer pairs were chosen to characterize nine cultivars in Bupleurum L.A total of 107 AFLP markers were amplified.On average,each combination amplified 26.75 markers including 23.25 polymorphic markers,with a polymorphic frequency of 86.92%.The Jaccard genetic similarity coefficients were from 0.61 to 0.93 and 0.39 to 0.86 in RAPD and AFLP by statistical analysis,respectively.UPGMA Cluster analysis based on AFLP and RAPD molecular markers data was used to construct a dendrogram of these cultivars.It revealed segregations of all nine cultivars into three main clusters.The dendrograms of RAPD and AFLP were similar but not identical.Conclusion So the genetic diversity of cultivars in Bupleurum L. could be analyzed and distinguished from intra-and inter-species by means of both AFLP and RAPD.Beacuse of a large number of loci and polymorphisms,the AFLP is better than RAPD for analysis on the genetic diversity of plants in Bupleurum L.

国家自然科学基金项目 (30672619);国家 “十一五” 科技支撑计划项目 (2006BAI09B04-01)