Identification of Pseudostellaria heterophylla from different idioplasms by analysis of rDNA ITS sequences / 中草药

ABSTRACT

Objective: To provide the DNA molecular marker for the identification of Pseudostellaria heterophylla from the different idioplasms by analysis of rDNA ITS sequences. Methods: PCR amplification, cloning, and sequencing were carried out using specified primer, and the rDNA ITS base sequences were compared. Results: The ITS mutation extension was 623-624 pb among nine idioplasms of P. heterophylla. Thereinto, the ITS-1 was 224 pb and its G + C content was 52.91%-54.26%, the 5.8S rDNA was 155 bp and its G + C content was 54.49%-55.13%, the ITS-2 was 244-245 bp and its G + C content was 55.55%-56.41%. There were 17 mutation sites (2.72%) in the whole ITS sequences. There were 7, 7, and 3 mutation sites in ITS1, ITS2, and 5.8S, respectively. The different idioplasms had a number of specific single nucleotide mutation sites. Their homologies with each other were upwards 99.9% and their sequence genetic distances were 0.003-0.013. These results showed that the mutation in species from different producing areas and idioplasms was within no more than one species. Conclusion: The mutation of ITS sequences could be used to authenticate P. heterophylla from different idioplasms.