In this study, the Inter Simple Sequence Repeats Polymerase Chain Reaction(ISSR-PCR) system in Abietinella abietina was optimized by orthogonal design with 4 levels of 5 factors. The results showed that the optimum ISSR-PCR reaction system for A. abietina was 25 μL total volume containing Taq DNA polymerase0.8 U, Mg2+ 1.5 mmol/L, d NTPs 0.4 mmol/L, primer 0.6 μmol/L and template DNA 40 ng. The sequence of the effective factors was Taq DNA polymerase>Primer>d NTPs>Template DNA>Mg2+. In addition, 12 suitable ...