用于SSR分析的大豆干种子DNA提取条件的优化

目的]探讨适于SSR分析的大豆干种子DNA提取的最佳方法。方法]以2个大豆品种的干种子为材料，分别采用改良SDS法和CTAB法提取大豆基因组DNA，用1％琼脂糖凝胶电泳检测DNA质量，用紫外分光光度计分别测定其DNA在A230、A260和A280下的吸光值，根据A260／A230和A260／A280的比值检测DNA的纯度和浓度，并分别以两种DNA为模版进行SSR—PCR扩增。结果]相同DNA提取条件下，SDS法提取DNA样品的纯度和浓度均高于CTAB法，SDS终浓度为2％（W／V），水浴15min，氯仿／异戊醇抽提2次时所提取大豆种子DNA的纯度及浓度最高，其DNA的0D260／0D280值为1．86，SDS法所提的DNA泳带分布较集中，无拖尾现象，其DNA浓度能够满足SSR扩增模板的需求。结论]SDS浓度为2％（W／V），水浴15min，氯仿／异戊醇抽提2次时提取大豆干种子DNA的浓度和纯度都较高，可以满足后续的各种分子生物学操作的要求。

Optimization of the Conditions for Extracting DNA for SSR Analysis from Dry Soybean Seeds

Objective] The purpose was to discuss the best way to extract DNA from dry seeds of soybean for SSR analysis.Method] With dry seeds of soybean as tested materials,genomic DNA of soybean was extracted with modified SDS method and CTAB method and examined with 1% agarose gel electrophoresis.The absorbance value was measured by ultraviolet spectrophotometer at A230、A260 and A280 and the ratio of A260/A230 and A260/A280 was used to determine the DNA purity and the mass concentration.DNA extracted with 2 methods was used as the template for SSR-PCR amplification.Result] The DNA purity and concentration of samples extracted with SDS method were higher than the CTAB method under the same conditions.The SDS concn.of 2%(W/V),water bath for 15 min and extracted 2 times with chloroform/isoamyl alcohol,the DNA purity and concentration extracted from soybean seed were the highest and the ratio of OD260/OD280 was 1.86.DNA bands extracted with SDS method were centralized distribution and non-tailing phenomenon which could meet the requirements of SSR amplification template.Conclusion] The SDS concn.of 2%(W/V),water bath for 15 min,extracted 2 times with chloroform/isoamyl alcohol,the ratio of OD260/OD280 was 1.86,which could meet the requirements of molecular biology research.