Mikami T, Harada T, Kinoshita T
Plant Breeding Institute, Faculty of Agriculture, Hokkaido University, Sapporo, Japan.
Curr Genet. 1986;10(9):695-700. doi: 10.1007/BF00410918.
Mitochondrial (mt) DNAs from normal (N) and male sterile (S) cytoplasms of sugar beet have been isolated and investigated by electron microscopy. The results showed that mtDNA was composed of a heterogeneous population of circular molecules. Their contour lengths varied from 0.28 to 51 micron, but unlike in the case of maize, a large difference was not observed in the distribution of molecular classes greater than 1.0 micron between N and S cytoplasms of sugar beet. On the other hand, N and S cytoplasms were shown to contain their own characteristic combinations of small circular mtDNA species with lengths between 0.28 micron and 0.6 micron. Mitochondrial DNAs from various sources of male-sterile cytoplasms were analyzed by agarose gel electrophoresis to determine the extent of cytoplasmic variation. Additional low molecular weight DNA bands appeared in all male-sterile lines examined, and as a result, three distinctive banding patterns were recognized. These data are in general agreement with those based upon restriction endonuclease digestion of mt and chloroplast DNAs and the genetic analysis of fertility restoration in test crosses.
通过电子显微镜对甜菜正常（N）细胞质和雄性不育（S）细胞质的线粒体（mt）DNA进行了分离和研究。结果表明，mtDNA由不同大小的环状分子群体组成。它们的轮廓长度从0.28微米到51微米不等，但与玉米不同的是，在甜菜的N和S细胞质中，大于1.0微米的分子类别的分布没有观察到很大差异。另一方面，N和S细胞质显示含有自身特有的小环状mtDNA种类组合，长度在0.28微米到0.6微米之间。通过琼脂糖凝胶电泳分析了来自各种雄性不育细胞质来源的线粒体DNA，以确定细胞质变异的程度。在所有检测的雄性不育系中都出现了额外的低分子量DNA条带，结果识别出三种不同的条带模式。这些数据总体上与基于mt和叶绿体DNA的限制性内切酶消化以及测交中育性恢复的遗传分析的数据一致。
