Extraction of DNA and Optimization of RAPD-PCR Protocol in 11 Species of Cymbidium

The method of CTAB-DNA isolation was optimized and used to extract genomic DNA from the tender leaves of 11 species of Cymbidium.DNA samples with superior quality and high yield could be gained by this method,and the A 260/A 280 values of tested samples were 1.7-1.9.To establish the reproducible RAPD-PCR protocol in Cymbidium,the concentrations of Mg2+,dNTPs,Taq DNA polymerase,and primers were also optimized in the present work.With the total volume of reaction was 25 μl,the optimal system using 75 ng genomic DNA,2.5 mmol/L Mg2+,0.15 mmol/L dNTPs,0.75 U Taq DNA polymerase,and 0.4 μmol/L primers,were employed to carry out PCR in 20 accessions from 11 species of Cymbidium.