Zhao Z G, Jiang L, Zhang W W, Yu C Y, Zhu S S, Xie K, Tian H, Liu L L, Ikehashi H, Wan J M
National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China.
Planta. 2007 Oct;226(5):1087-96. doi: 10.1007/s00425-007-0553-8. Epub 2007 Jun 5.
Partial abortion of female gametes and the resulting semi-sterility of indica x japonica inter-subspecific rice hybrids have been ascribed to an allelic interaction, which can be avoided by the use of wide compatibility varieties. To further understand the genetic mechanism of hybrid sterility, we have constructed two sets of hybrids, using as male parent either the typical japonica variety Asominori, or the wide compatibility variety 02428; and as female, a set of 66 chromosome segment substitution lines in which various chromosomal segments from the indica variety IR24 have been introduced into a common genetic background of Asominori. Spikelet semi-sterility was observed in hybrid between CSSL34 and Asominori, which is known to carry the sterility gene S31 (Zhao et al. in Euphytica 151:331-337, 2006). Cytological analysis revealed that the semi-sterility of the CSSL34 x Asominori hybrid was caused primarily by partial abortion of the embryo sac at the stage of the mitosis of the functional megaspore. A population of 1,630 progeny of the three-way cross (CSSL34 x 02428) x Asominori was developed to map S31. Based on the physical location of linked molecular markers, S31 was thereby delimited to a 54-kb region on rice chromsome 5. This fragment contains eight predicted open reading frames, four of which encode known proteins and four putative proteins. These results are relevant to the map-based cloning of S31, and the development of marker-assisted transfer of non-sterility allele inducing alleles to breeding germplasm, to allow for a more efficient exploitation of heterosis in hybrid rice.
雌配子部分败育以及由此导致的籼粳亚种间杂交水稻半不育现象被归因于一种等位基因互作，而利用广亲和品种可避免这种现象。为了进一步了解杂种不育的遗传机制，我们构建了两组杂交种，分别以典型粳稻品种“秋光”或广亲和品种“02428”为父本；以一组66个染色体片段代换系为母本，这些代换系中已将籼稻品种“IR24”的各种染色体片段导入到“秋光”的共同遗传背景中。在CSSL34与“秋光”的杂交种中观察到了小穗半不育现象，已知CSSL34携带不育基因S31（Zhao等人，《欧洲植物病理学报》151:331 - 337，2006年）。细胞学分析表明，CSSL34与“秋光”杂交种的半不育主要是由功能大孢子有丝分裂阶段胚囊的部分败育引起的。构建了三交组合（CSSL34×02428）ד秋光”的1630个后代群体用于定位S31。基于连锁分子标记的物理位置，S31被定位到水稻第5染色体上一个54 kb的区域。该片段包含8个预测的开放阅读框，其中4个编码已知蛋白质，4个为推测蛋白质。这些结果与基于图谱克隆S31以及将非不育等位基因导入育种种质的标记辅助转移相关，以便更有效地利用杂交水稻的杂种优势。
