在DNA分子水平上讨论属的概念

Studies on the Concept of Genus at the Level of DNA Molecules

对ＤＮＡ分子进行特异性剪切的限制酶技术可以为植物分类学上重要的分类阶层─—屑的分界提供分子生物学的依据。芸苔属Ｂｒａｓｓｉｃａ的５种植物线粒体基因组的遗传距离（ｐ）的差异矩阵应用ＵＰＧＭＡ法构建出系统树；由此而提出区分不同属的ｐ值为０．０１９５。

The restriction enzyme technique for the specific cleavage of DNA molecules provides amolecular basis for the study of an importan t taxonomic unit genus. A phylogenetic tree ofthe mitochondrial genomes for 5 Brassica species has been drawn by the UPGMA (unweighted pair groupmean arithmetic average)method applied to the matrix of genetic distances(p).The critical p value to separatetwo taxa into different genera was p=0. 01 95.