PDF(Pubmed)
Abstract：
Maize (Zea mays L.) C-type cytoplasmic male sterility (CMS-C) is a highly used CMS system for maize commercial hybrid seed production. Rf4 is the major dominant restorer gene for CMS-C. Inbreds were recently discovered which contain the restoring Rf4 allele yet are unable to restore fertility due to the lack of an additional gene required for Rf4\'s restoration. To find this additional gene, QTL mapping and positional cloning were performed using an inbred that contained Rf4 but was incapable of restoring CMS-C. The QTL was mapped to a 738-kb interval on chromosome 2, which contains a Pentatricopeptide Repeat (PPR) gene cluster. Allele content comparisons of the inbreds identified three potential candidate genes responsible for fertility restoration in CMS-C. Complementation via transformation of these three candidate genes showed that PPR153 (Zm00001eb114660) is required for Rf4 to restore fertility to tassels. The PPR153 sequence is present in B73 genome, but it is not capable of restoring CMS-C without Rf4. Analysis using NAM lines revealed that Rf4 requires the presence of PPR153 to restore CMS-C in diverse germplasms. This research uncovers a major CMS-C genetic restoration pathway and can be used for identifying inbreds suitable for maize hybrid production with CMS-C cytoplasm.
摘要：
玉米（ZeamaysL.）C型细胞质雄性不育（CMS-C）是用于玉米商业杂交种子生产的高度使用的CMS系统。Rf4是CMS-C的主要显性恢复基因。最近发现了包含恢复Rf4等位基因的自交系，但由于缺乏Rf4恢复所需的其他基因，因此无法恢复生育力。为了找到这个额外的基因，使用含有Rf4但无法恢复CMS-C的近交系进行QTL定位和位置克隆。QTL定位于2号染色体上的738kb间隔，该间隔包含五肽重复（PPR）基因簇。自交系的等位基因含量比较确定了负责CMS-C中生育力恢复的三个潜在候选基因。通过转化这三个候选基因的互补表明，Rf4需要PPR153（Zm00001eb114660）来恢复雄花的生育力。PPR153序列存在于B73基因组中，但它不能在没有Rf4的情况下恢复CMS-C。使用NAM系的分析表明，Rf4需要PPR153的存在才能恢复不同种质中的CMS-C。这项研究揭示了主要的CMS-C遗传恢复途径，可用于鉴定适合CMS-C细胞质玉米杂种生产的自交系。
