为了建立一个重现性好、稳定性高，适用于海带属ISSR遗传分析的PCR反应体系，从海带属配子体材料中提取基因组DNA作为模板，应用正交设计试验对反应体系中各因子的不同浓度进行组合优化。结果显示：适用于海带ISSR 扩增反应的最佳体系(20 μL)为：1×PCR buffer，1.2 mmol/L Mg2 +，0.2 mmol/L dNTPs，1.0 μmol/L ISSR 引物，40 ng 模板DNA，0.25 U Taq DNA 聚合酶；扩增PCR 程序为：95℃预变性3 min；95℃变性45 s，52℃退火45 s，72℃延伸2 min，共38 个循环；最后72℃延伸10 min。在优化的海带ISSR 反应条件下，扩增条带稳定，重现性好，为应用ISSR 分子标记技术进行海带属遗传多样性研究和分子鉴定奠定了技术基础。

In order to establish a reproducible, stable, and suitable reaction system of Saccharina for ISSR analysis of genetic differences, the genomic DNA extracted from gametophytes of Saccharina was used as template, the different concentrations of the factors in reaction system were optimized by orthogonal design experiment. The results showed that, the optimal ISSR reaction system (20 μL) contained 1 ×PCR buffer, 1.2 mmol/L Mg2 , 0.2 mmol/L dNTPs, 1 μmol/L ISSR primer, 40 ng template DNA and 0.25 U Taq DNA polymerase. The PCR program was pre-denatured at 95℃ for 3 min and followed by 38 cycles of 45 s at 95℃, 45 s at 52℃, 2 min at 72℃, and final extension of 10 min at 72℃. The optimal ISSR reaction system was stable and repeatable. This system could provide the technical foundation for the application of ISSR molecular marker technology for the study on genetic diversity and molecular identification ofSaccharina .