Department of Plant Genetics and Breeding, Institute of Field and Garden crops, ARO, The Volcani Center, 50250, Bet Dagan, Israel.
Theor Appl Genet. 1992 Sep;84(7-8):829-34. doi: 10.1007/BF00227392.
The Cytoplasmic Male Sterility (CMS)-associated region in Petunia, the S-Pcf locus, was defined by the analysis of recombinant mitochondrial genomes of somatic hybrid plants resulting from a fusion of protoplasts from CMS and fertile lines. The presence of the S-Pcf locus was shown to correlate with the CMS trait in stable somatic hybrids and in other CMS Petunia lines. A small population of unstable, sterile somatic hybrids was also generated in this fusion, most of which underwent cytoplasmic segregation in subsequent generations. Stable revertants of such sterile somatic hybrids were shown to lose the S-Pcf locus. In this paper we present a molecular and genetic analysis of unstable progenies of an unstable, sterile somatic hybrid plant derived from the same fusion experiment. Both male-sterile and fertile progenies of this somatic hybrid plant have shown continuous segregation of fertile and male-sterile progenies. All segregants in this line contained, and transcribed, the S-Pcf locus. Genetic analysis indicated the presence of various levels of multiple nuclear fertility-restoration genes in this group of progenies. These findings consolidate the association between the S-Pcf locus and the CMS trait in Petunia. It also shows that the restoration of fertility by the multiple nuclear gene system does not affect the transcription of the S-Pcf locus and that the presence of an intact S-Pcf locus is necessary in order to maintain the potential sterility in the cytoplasm.
花粉败育相关的细胞质雄性不育（CMS）区域，在矮牵牛的 S-Pcf 基因座，通过对来自 CMS 和可育系原生质体融合的体细胞杂种的重组线粒体基因组的分析进行了定义。S-Pcf 基因座的存在与稳定的体细胞杂种和其他矮牵牛 CMS 品系中的 CMS 特性相关。在该融合中也产生了一小部分不稳定的、不育的体细胞杂种，其中大多数在随后的世代中经历了细胞质分离。这种不育体细胞杂种的稳定回复突变体被证明失去了 S-Pcf 基因座。在本文中，我们对同一融合实验中衍生的不稳定、不育体细胞杂种的不稳定后代进行了分子和遗传分析。该体细胞杂种的雄性不育和可育后代均表现出可育和雄性不育后代的连续分离。该系的所有分离物均包含并转录了 S-Pcf 基因座。遗传分析表明，该组后代中存在多种水平的多个核育性恢复基因。这些发现巩固了 S-Pcf 基因座与矮牵牛 CMS 特性之间的关联。它还表明，由多个核基因系统恢复育性不会影响 S-Pcf 基因座的转录，并且为了维持细胞质中的潜在不育性，完整的 S-Pcf 基因座是必需的。
