中文摘要：

以广西区6种十大功劳属植物为材料，采用PCR直接测序法测定其nrDNAITS序列，以GenBank中的察瓦龙小檗的序列为外群对照，利用MEGA2．1软件构建7种植物的系统发育树，分析它们的亲缘关系。结果表明：（1）十大功劳属广西区6种植物的ITS序列长度在691-692间，ITS中G＋C含量的变化范围为40．52％～42．67％，序列问的遗传分化距离为0．000～0．028，平均值为0．017；（2）NJ、MP、ME聚类树的分支趋势一致，六种十大功劳属植物都聚为一支，都以高支持率（96％以上）将小果十大功劳、阔叶十大功劳和十大功劳聚在一起，然后再和其他3种十大功劳属植物相聚，说明6种十大功劳的亲缘关系都比较近，但小果十大功劳，阔叶十大功劳和十大功劳这3个种的亲缘关系最为密切；（3）在6种十大功劳植物中，分布海拔相同以及分布区域有重叠的种类先相聚，可见这些物种的亲缘关系密切。

英文摘要：

Genetic relationships of 6 Mahonia species in Guangxi region were analysed. PCR products of DNA, extracted from 6 Mahonia species, were used for the determination of nuclear rDNA （nrDNA） ITS sequences. Ber- beris tsarongensis, whose sequence found in Genbank, was served as out group control. Phylogenetic trees of 7 species were established, using MEGA2.1 softwere. The results showed that： （1） The sequences of ITS in 6 Mahonia species ranged from 691 bp to 692 bp in length. The G＋C content varied from 40.52% to 42.67%. The genetic distances varied from 0.000 to 0.028, with an average of 0.017; （2） The branch tendency ofNJ, MP, ME trees was similar. 6 Mahonia species clustered together. M. fortunei, M. bealei and M. bodinieri clustered together with a high bootstrap （96%） then grouped with three species of Mahonia. The result also showed that there was close relations- hips in 6 Mahonia species. Moreover, there was closer relationship in M. fortunei, M. bealei and M. bodinieri. （3） The species with similar morphological characters and from the same areas or neighboring geographical regions were firstly clustered together in the 6 kinds of plants, respectively. It suggested that they had higher genetic similarities and close relations.