使用1对引物18SP1和26SP2对采自14个产区的太子参〔Pseudostellaria heterophylla (Miq.)Pax ex Pax et Hoffm.〕进行ITS基因的PCR扩增和测序。序列分析结果表明,14个产区太子参的ITS1片段长度为219～222bp,ITS2片段长度为235～236bp,5.8S片段长度为155～157bp。除江苏宜兴,江苏句容马梗,江苏南京老鹰山和江苏溧阳等4个产区的ITS序列碱基完全一致外,其他10个产区的ITS序列则有不同的变异,碱基变异数目(包括5 8S编码区)为1～17个。使用UPGMA法重建系统发生树,从分子生物学角度说明了它们的变异程度,为利用ITS区序列的差异鉴别不同产区的太子参提供了依据。

A pair of primers of 18SP1 and 26SP2 were used to study the ITS sequences of Pseudostellaria heterophylla ( Miq. )Pax ex Pax et Hoffm. from 14 different geographical regions by PCR technique. Sequences analysis showed that ITS1 is 219-226 bp , ITS2 235-236 bp and 5. 8S 155-157 bp. Among 14 regions, except 4 sequences of ITS of P. heterophylla from Yixin, Mageng of Jurong, Laoying Mountain in Nanjing and Liyang of Jiangsu showed no variation, there are 1 -17 variable sites ( including 5. 8S coding region) in pairwise comparison of other 10 regions. Phylogenetic tree basedon ITS1, ITS2 and 5. 8S sequences data was reconstructed by using UPGMA methods, which shows the variation at the level of molecular biology. It provided the basis for identifing P.heterophylla from different geographical regions according to the variation of the ITS sequences.