中文摘要：

目的：选择云南境内应用面较广、市场流通量较大的14个石斛品种，建立其 DNA条形码鉴定方法。方法：结合Genbank数据库序列，选择ITS、psbA－trnH、matK、rbcL等4条常用序列对石斛DNA样品进行扩增和测序，利用MEGA5．0计算种间种内 K2P遗传距离并构建NJ树，同时采用Taxon DNA软件计算Barcoding gap （条形码种内种间遗传差异）。结果：ITS序列的K2P种内遗传距离小于种间遗传距离，NJ树可以很好地将不同品种的石斛分开，且有较明显的Barcoding gap。结论：ITS序列可以作为鉴别这14种滇产主要石斛的优选序列。

英文摘要：

Objective To identify 14 species of Dendrobium which widely used in Yunnan province by DNA barcoding.Methods Three chloroplast sequences including psbA-trnH,matK,rbcL and an ribosomal DNA ITS sequence of the 14 species were compara-tively analyzed.K2P distances were calculated and NJ Tree was performed applying MEGA 5. 0. Meanwhile,Barcoding gap were calcu-lated by Taxon DNA.Results The interspecific K2P distance of ITS were higher than the intraspecific one.And NJ tree could also di-vide species into different clades.The barcoding-gap were obvious between intra-and inter-species.Conclusions ITS sequence can be the optimal barcode to identify the 14 species of Dendrobium.