中文摘要：

[目的]制备和检测大白菜延伸DNA纤维。[方法]以大白菜幼叶为材料，采用刀切分离细胞核、SDS释放DNA、盖玻片滑动牵拉DNA的方法，首次获得大白菜DNA延伸纤维。[结果]以基因组DNA和25SrDNA为探针进行原位杂交检测，该DNA纤维长度大约为1．93Mb，25SrDNA在大白菜基因组中的拷贝数在258—687之间。该方法获得的DNA延伸纤维平行、清晰、适合FISH分析。[结论]该研究将会促进大白菜基因图谱的构建和组织分析。

英文摘要：

Abstract [Objective] The paper was to prepare and detect the extended DNA fibers of Chinese cabbage. [Method] Chinese cabbage nuclei was first successfully isolated by chopping young leaves with a blade, then nuclei were lysed by SDS to release DNA, and DNA fibers were dragged and extended with a coverslip. [Result] The results of Fiber-FISH with genomic DNA and 25S rDNA as probes showed that DNA fiber size as long as about 1.93 Mb could be measured and the number of 25S rDNA copies region were estimated to be 258 and 687 in Chinese cabbage genome. DNA fibers prepared by this method showed equally spread parallel thread with clear background, and were suitable for FISH analysis. [Conclusion] The study would accelerate Chinese cabbage genome mapping and organization analysis.