Conserved Region Amplification Polymorphism (CoRAP), a Novel Marker Technique for Plant Genotyping in Salvia miltiorrhiza

Salvia miltiorrhiza (SM), a widely popular Chinese herb, is grown in various regions in China. Identifying SMs grown in different provinces of China is difficult, and therefore genotyping these collections would be highly valuable. Based on the techniques of sequence-related amplified polymorphism and target region amplified polymorphism, a novel PCR-based molecular marker technique called conserved region amplification polymorphism (CoRAP) is reported in this study to genotype SMs. The CoRAP technique is based on the use of two primers: fixed and arbitrary primers. The former is derived from target EST sequences deposited in Genbank; while, the core sequence (CACGC) of the latter is a conserved region found in most introns. In the present study, we utilized CoRAP to genotype SMs from different geographical origins. PCR amplification is performed for 30 cycles at an annealing temperature of 52 degrees C. Each PCR reaction has generated as many as 30-50 fragments of 50 to 1,000 bp in size. The successful DNA genotyping of SMs by CoRAP was achieved. This new genotyping method is rapid, efficient, and reproducible.