Genomic DNA Extraction and RAPD Analysis for Gastrodia elata Bl. (Orchidaceae) Using an Improved Method

One improved randomly amplified polymorphic DNA (RAPD) technique has been used in animal phylogenetic relationships and fingerprints analysis by prolonging the ramp time. However, little was known whether the PCR ramp time and G/C content of primers effect on RAPD analysis of medicinal Gastrodia elata Bl. plants. The present study was conducted with the objectives to extract genomic DNA of G. elata, execute RAPD analysis with different PCR ramp time and discuss the relationship between the amplification efficiency and the G/C content of RAPD primers subsequently. The Cetyltrimethylammonium Bromide (CTAB) protocol was used in the genomic DNA extraction. Ten RAPD primers were randomly selected in PCR amplifications. The ramp time parameters from annealing to extension were used 0.3 and 3°C sec-1, respectively. The concentration of G. elata genomic DNA were about 50 ng μL-1 with a 1.93 purity. Obviously, the amplified band numbers and resolution were improved when using a 0.3°C sec-1 ramp time in the RAPD analysis. The band number increase is closely related to the G/(G+C) ratio of RAPD primers. Therefore, the extracted G. elata genomic DNA is suitable for PCR amplifications and the prolonged ramp time is helpful to improve the RAPD resolution and production. These are valuable references for molecular identification and biodiversity analysis of G. elata populations.