Abstract: In order to establish the optimal reaction of RAPD-PCR amplification for Eomecon chionantha Hance, the following parameters were optimized: the concentrations of Mg²⁺, template DNA, dNTPs, primers and Taq DNA polymerase. The optimal RAPDPCR reaction system was as follows a total volume of 25 μL contains 2.5 μL 10×Buffer, 1.8 mmol·L^-1 Mg²⁺，2 U Taq DNA polymerase, 50 ng template DNA, 0.2 mmol·L^-1 dNTPs and 1.6 μmol·L^-1 primer. The reaction program fitting to the RAPD-PCR was as follows: initial denaturation at 94℃ for 2 min, followed by 5 beforehand cycles of 94℃ for 20 s, 36℃ for 30 s, 72℃ for 75 s; followed by 40 cycles of 94℃ for 20 s, 40℃ for 30 s, 72℃ for 60 s, and a final exposure to 72℃ for 20 min, then stored in 4℃. This RAPD-PCR system has some distinguising features including clear marker site, stable reaction system, reliable abundant polymorphisms, and better repeatability. It is suitable for the study on genetic diversity of E.chionantha.

Key words: RAPD, reaction system, optimization, Eomecon chionantha Hance