Molecular Identification of Trichosanthes kirilowii and Its Adulterants Using ITS2 Sequence Fragments
Molecular identification based on ITS2 sequence fragments was conducted of Trichosanthes kirilowii,a Chinese herbal medicine plant,and its adulterants on the medicine market.We treated the roots of 8 experimental samples for DNA extraction and purification,PCR amplification and bidirectional sequencing to get the ITS2 sequences.Then the 8 ITS2 sequences obtained by experiment and 7 downloaded ITS2 sequences from GenBank database were aligned using ClustalX,with manual adjustments assisted by BioEdit.MEGA program version 5.0 was employed to estimate the intraspecific and interspecific genetic distance.NJ and ML trees were constructed using K-2P distance method in order to evaluate the identification results.The range of intraspecific difference space of all Chinese herbal plants was 0-0.077 9,with a mean value of 0.019,while the interspecific distance ranged from 0.004 to 0.594,with a mean value of 0.436.The interspecific value was significantly greater than the intraspecific value.NJ and ML phylogenetic trees of different species of T.kirilowii and its adulterants were constructed and the two phylogenetic trees were consistent with each other.Each species was clustered into one branch,thus forming a monophyletic group,with a support rate of ＞50％.The results showed that the ITS2 barcoding is a fast and accurate method for the identification of T.kirilowii and its adulterants.
NETL
NSTL
万方数据
维普
