Applied Plant Research Laboratory, Japan Tobacco Inc, Idei 1900, Oyama, 323, Tochigi, Japan.
Theor Appl Genet. 1992 Sep;84(7-8):819-24. doi: 10.1007/BF00227390.
Somatic hybrids between the Japanese radish and cauliflower (Brassica oleracea) were produced by protoplast electrofusion in order to introduce clubroot disease resistance in the Japanese radish (Raphanus sativus) into Brassica crops. After electrofusion of iodoacetamide-treated cauliflower protoplasts with untreated radish ones, culture was performed under conditions, that allowed only cauliflower protoplasts to regenerate. Out of 40 regenerated plants, 37 were morphologically of a hybrid type and 3 of a cauliflower type. On the basis of isozyme and RFLP analysis, all of the hybrid-type plants tested proved to be true hybrids. Of the 10 true hybrids tested, 9 were found to contain chloroplasts similar to those found in the Japanese radish, while only 1 contained those of the cauliflower. Using two mitochondrial genes as probes, we were able to show that 3 hybrids contained mitochondria of the Japanese radish, with some modification, while 7 hybrids had either parental or new patterns. All of the hybrid-type plants showed resistance to clubroot disease as high as that found in the Japanese radish. Some hybrids were self-fertile. All of the self-fertile hybrids were found to contain 36 chromosomes, indicating that they were amphidiploids. In addition, a few seeds were obtained from a backcross of the self-fertile hybrids to both parents.
为了将萝卜（Raphanus sativus）的根肿病抗性引入芸薹属作物，通过原生质体电融合技术将日本萝卜和花椰菜（Brassica oleracea）产生体细胞杂种。在用碘乙酰胺处理的花椰菜原生质体与未经处理的萝卜原生质体电融合后，在只允许花椰菜原生质体再生的条件下进行培养。在 40 株再生植株中，有 37 株形态为杂种型，3 株形态为花椰菜型。基于同工酶和 RFLP 分析，所有测试的杂种型植株均被证实为真正的杂种。在测试的 10 株真正杂种中，有 9 株被发现含有与日本萝卜相似的叶绿体，而只有 1 株含有花椰菜的叶绿体。使用两个线粒体基因作为探针，我们能够证明 3 个杂种含有日本萝卜的线粒体，经过一些修饰，而 7 个杂种具有亲本或新的模式。所有杂种型植株均表现出与日本萝卜相当的根肿病抗性。一些杂种是自交可育的。所有自交可育的杂种都被发现含有 36 条染色体，表明它们是双二倍体。此外，从自交可育杂种与双亲的回交中获得了一些种子。
