Abstract: To obtain clear Sequence-related amplified polymorphism (SRAP) fingerprints of Cymbidium, the factors influencing SRAP analysis were studied. A reliable, effective and reproductive PCR reaction system for detecting SRAP was developed. Each 30 μL PCR reaction mixture consisted of 2.2 mmol/μL of Mg2+, 0.8 mmol/L of dNTPs, 150 ng of genomic DNA, 1.5 μmol/L of primer and 2.0 unit of Taq polymerase. Samples were subjected to thermal profile for amplification in an oven thermocycler: 4 min of denaturing at 94 ℃, five cycles of three steps, 1 min of denaturing at 94 ℃, 1 min of annealing at 35 ℃ and 1 min of elongation at 72 ℃, in the following 30 cycles the annealing temperature was increased to 55 ℃, with a final elongation step of 5 min at 72 ℃.

Key words: Cymbidium; template DNA, SRAP-PCR, reaction system, optimization

摘要： 为获得兰属清晰的SRAP标记图谱，对兰属SRAP-PCR反应体系进行了初步探讨，建立了扩增多态性高、重复性好、带型清晰的SRAP-PCR反应体系。最佳反应体系：在30 μL反应总体系中，Mg2+ 2.2 mmol/L、dNTPs 0.8 mmol/L、DNA模板150 ng、DNA聚合酶2.0 U，上、下游引物各1.5 μmol/L；扩增程序：在94 ℃预变性4 min，反应前5个循环在94 ℃变性1 min、35 ℃复性1 min、72 ℃延伸1 min的条件下运行，随后的30个循环复性温度提高至55 ℃，最后72 ℃延伸5 min．

关键词: 兰属, DNA模板, SRAP-PCR反应体系, 优化