Formanová Natasa, Li Xiu-Qing, Ferrie Alison M R, Depauw Mary, Keller Wilf A, Landry Benoit, Brown Gregory G
Department of Biology, McGill University, Montreal, Quebec, Canada.
Plant Mol Biol. 2006 May;61(1-2):269-81. doi: 10.1007/s11103-006-0008-9.
The Polima (pol) system of cytoplasmic male sterility (CMS) and its fertility restorer gene Rfp are used in hybrid rapeseed production in Brassica napus. To facilitate map-based cloning of the Rfp gene, we have successfully transferred the pol cytoplasm and Rfp from the amphidiploid B. napus to the diploid species B. rapa and generated a doubled haploid pol cytoplasm B. rapa population that segregates for the Rfp gene. This was achieved through interspecific crosses, in vitro rescue of hybrid embryos, backcrosses, and microspore culture. Male fertility conditioned by Rfp was shown to co-segregate in this population with Rfp-specific mitochondrial transcript modifications and with DNA markers previously shown to be linked to Rfp in B. napus. The selfed-progeny of one doubled haploid plant were confirmed to be characteristic B. rapa diploids by cytogenetic analysis. Clones recovered from a genomic library derived from this plant line using the RFLP probe cRF1 fell into several distinct physical contigs, one of which contained Rfp-linked polymorphic restriction fragments detected by this probe. This indicates that chromosomal DNA segments anchored in the Rfp region can be recovered from this library and that the library may therefore prove to be a useful resource for the eventual isolation of the Rfp gene.
甘蓝型油菜细胞质雄性不育（CMS）的波里马（pol）系统及其育性恢复基因Rfp被用于甘蓝型油菜杂交种的生产。为便于基于图谱克隆Rfp基因，我们已成功地将双二倍体甘蓝型油菜的pol细胞质和Rfp基因转移到二倍体物种白菜型油菜中，并获得了一个加倍单倍体pol细胞质白菜型油菜群体，该群体因Rfp基因而发生分离。这是通过种间杂交、杂种胚的离体拯救、回交和小孢子培养实现的。在该群体中，由Rfp决定的雄性育性与Rfp特异性线粒体转录本修饰以及先前在甘蓝型油菜中显示与Rfp连锁的DNA标记共分离。通过细胞遗传学分析证实，一株加倍单倍体植株的自交后代为典型的白菜型油菜二倍体。使用RFLP探针cRF1从该株系的基因组文库中获得的克隆落入几个不同的物理重叠群，其中一个包含该探针检测到的与Rfp连锁的多态性限制性片段。这表明可以从该文库中获得锚定在Rfp区域的染色体DNA片段，因此该文库可能被证明是最终分离Rfp基因的有用资源。
