To obtain high-quality DNA suitable for methylation-sensitive amplification polymorphism (MSAP), analysis, the mature cotyledon and tissue cultured cotyledon of walnut cultivar‘Liaoning-1’were used as the testing materials in the research of DNA isolation by 3 methods (SDS, high salt CTAB and modified high salt CTAB) and the mature leaf tissue was taken as the control. The concentration and intactness of the extracted DNA were determined using a spectrometer and by electrophoresis in 0.8% (w/v) agarose gels against standard solutions of lambda DNA. High quality DNA was extracted from leaf tissues using the high salt CTAB method and the modified high salt CTAB method. No detectable DNA was extracted from the mature cotyledon and cultured cotyledon using SDS method. The DNA with high quality but little quantity was extracted from the mature cotyledon but not the extract cultured cotyledon using the high salt CTAB method. The DNA with high quantity and quality suitable for MSAP analysis from both mature cotyledon and cultured cotyledon was extracted using the modified high salt CTAB method. The DNA extraction method of walnut cotyledon suitable for MSAP analysis was established, which could lay foundation for downstream molecular biology experiment and provide a reference to the polysaccharide removal research in DNA extraction procedure.

以‘中宁强’核桃品种成熟叶片为材料,采用优化的 MSAP 反应体系,在全基因组水平对核DNA 进行甲基化修饰位点分析,结果表明:选用20对引物组合,共扩增出1 060条清晰、重复性好的谱带,平均每对引物扩增出53条谱带,其中,甲基化位点241个,甲基化修饰比例为22.73%. 对部分核桃 DNA 甲基化修饰位点进行回收测序,得到10条存在 DNA 甲基化修饰的 DNA 序列,BLASTn分析表明,核桃基因组中多种类型的DNA序列存在甲基化修饰现象.

目的 采用将同一品种嫁接到不同砧木的方法，经过调查测试和分析，揭示杂交种‘中宁奇’的砧木特性，进而阐明砧木在经济林育种和栽培中的地位和作用。 方法 以砧穗组合上宋-14/中宁奇和上宋-14/宁优为试材，测定分析不同砧穗组合的生长量和光合特性指标。 结果 嫁接亲和性调查显示：2种砧木对同一核桃品种的嫁接亲和性均较高，但差异不显著。树体生长特性调查表明：上宋-14/中宁奇树高、干径、冠幅、新梢长度、新梢粗度、新梢着生小叶数及分枝力等指标显著或极显著高于上宋-14/宁优，‘中宁奇’作砧木可显著增强核桃树体的生长势。光合特性分析结果显示：2种砧穗组合间光响应曲线特征参数存在显著差异，上宋-14/中宁奇最大净光合速率（21.93 μmol·m^-2·s^-1）、光饱和点（1 550 μmol·m^-2·s^-1）及表观量子效率（0.062 mol·mol^-1）分别比上宋-14/宁优提高17.90%、11.51%和16.98%，而光补偿点（16.53 μmol·m^-2·s^-1）则显著降低35.33%。 结论 核桃杂交种‘中宁奇’与‘上宋-14’核桃品种有较强的亲和性，以‘中宁奇’作砧木可显著提高树体的生长量和光合能力，使嫁接品种对光强的利用范围变广，从而提高树体对光环境的适应性。