title: [Application of allele-specific primer in the identificatin of Hedyotis diffusa].
abstract: OBJECTIVE
  To develop a convenient and effective method for the identification of Hedyotis diffusa.
  
  
  METHODS
  DNA templates were extracted from H. diffusa and its adulterants samples on commercial markets. And DNA fragments of rDNA ITS-2 regions were amplified and sequenced subsequently. ITS-2 sequences of all samples were aligned. The allele-specific primer was designed for distinguishing H. diffusa.
  
  
  RESULTS
  The nucleotide difference between H. diffusa and 8 other species is obvious in the ITS-2 region. In addition, the allele-specific primers were employed to amplify the DNA from H. diffusa and 8 other species. The result indicated that a 392 bp DNA fragment was amplified from H. diffusa, whereas no any fragment was amplified from 8 other species under the same reaction condition.
  
  
  CONCLUSIONS
  The primers designed in the present study were highly specific for H. diffusa. They could be used as key components in the H. diffusa identification kit.
authors.affiliation: Department of Biology, Yancheng Teachers College, Yancheng 224002.
authors.forename: Zhongquan
authors.initials: Z
authors.lastname: Liu
authors.forename: Minggan
authors.initials: M
authors.lastname: Hao
authors.forename: Jialian
authors.initials: J
authors.lastname: Wang
mesh_terms: D000483:Alleles; D017931:DNA Primers / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics / Q000302:isolation & purification; D021903:DNA, Ribosomal Spacer / Q000235:genetics*; D004340:Drug Contamination; D032064:Hedyotis / Q000235:genetics*; D010946:Plants, Medicinal / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D011786:Quality Control; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D018744:DNA, Plant; D021903:DNA, Ribosomal Spacer