[关键词]
[摘要]
目的 开展川续断种质资源的遗传多样性研究,为合理利用川续断种质资源提供理论依据。方法 运用SRAP分子标记方法对川黔境内川续断的遗传多样性进行分析。结果 10对引物共检测到124个位点,其中102个位点具有多态性,多态位点百分率(PPL)为82.26%。川续断总的Nei’s基因多样性指数(H)为0.280 0,Shannon’s多态性信息指数(I)为0.435 3;居群水平上川续断的PPL为53.92%,H为0.121 2~0.244 0、I为0.179 6~0.361 1,其中5个高海拔、小生境特征的居群遗传多样性指标较高。居群间的基因分化系数Gst为0.293 0,基因流(Nm)为1.206 4。基于遗传相似度,14个居群可聚为3类。结论 川续断居群的遗传多样性水平丰富,遗传变异主要存在居群内,地理位置(海拔)和气候是川续断居群遗传多样性较高的影响因素,而地理隔离(小生境)是造成居群内遗传变异高于居群间的另一因素。
[Key word]
[Abstract]
Objective ITS2 barcoding was used to discriminate Zanthoxyli Radix and its adulterants to ensure the quality and clinical safety of this Chinese materia medica. Methods The internal transcribed spacer 2 (ITS2) regions were amplified and sequenced bi-directionally. Then the obtained sequences were assembled using the CodonCode Aligner. The ITS2 regions were obtained using the hidden Markov model (HMM)-based annotation methods. The genetic distances of the ITS2 regions were computed in accordance with the kimura 2-parameter (K2P) model and Neighbor-joining (NJ) phylogenetic trees were constructed using MEGA5.0. Results The length of ITS2 sequences of the plants in Zanthoxyli Radix and its adulterants were between 224 and 227 bp. Their mean intraspecific genetic distance (K2P distance) was lower than their mean interspecific genetic distance with the adulterants. The NJ trees showed that the roots of Zanthoxyli Radix could be easily distinguished from its adulterants. Conclusion ITS2 barcode could be used to identify the roots of Zanthoxyli Radix and its adulterants effectively, and provide the important molecular evidence for the authentication of germplasm resources.
[中图分类号]
[基金项目]
国家自然科学地区基金资助项目(81160501);国家“十一五”科技支撑项目(2009BA174B01);贵阳市科技创新公共技术平台项目(2010筑科合字第3-2号)