Jing Wen, Zhang Wenwei, Jiang Ling, Chen Liangming, Zhai Huqu, Wan Jianmin
State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, 210095, Nanjing, China.
Theor Appl Genet. 2007 Mar;114(5):915-25. doi: 10.1007/s00122-006-0489-6. Epub 2007 Feb 8.
Partial pollen sterility has been observed in hybrid progeny derived from a japonica cultivar, Akihikari and a weedy strain, Ludao, which naturally grows in Jiangsu province of east China. Cytological and histological analyses revealed that pollen abortion occurred largely at the bicellular pollen stage, primarily due to the gradual disaggregation of generative and vegetative cells. A genome-wide analysis was further carried out in a backcross population of Akihikari //Ludao/Akihikari using a total of 118 simple sequence repeat (SSR) markers and an expressed sequence tag (EST) marker distributed on the entire rice linkage map. Two loci controlling hybrid pollen sterility, designated as S33(t) and S34(t), were located on chromosomes 3 and 11, respectively. Both loci were putatively different from all the previously reported gametophyte genes and hybrid pollen sterility loci. Interaction between the Ludao and Akihikari alleles at each of the two loci resulted in reduction of fertility in the pollens carring the Ludao alleles. To map the precise location of the major locus, S33(t), we selected 165 plants of the backcross population with pollen fertility higher than 80.0%, and assayed the recombinant events surrounding the S33(t) locus using newly developed SSR markers. The S33(t) was delimited to an 86 kb region between SSR markers RM15621 and RM15627. Sequence analysis of this region indicated that there were ten open reading frames. These results will be valuable for cloning this gene and marker-assisted transferring of the corresponding neutral allele in rice breeding programs. Furthermore, the origin of the weedy strain Ludao is discussed.
在中国东部江苏省自然生长的杂草稻株系“绿稻”与粳稻品种“秋光”的杂交后代中观察到部分花粉不育现象。细胞学和组织学分析表明，花粉败育主要发生在二细胞花粉阶段，主要原因是生殖细胞和营养细胞逐渐解体。利用分布在整个水稻连锁图谱上的总共118个简单序列重复（SSR）标记和一个表达序列标签（EST）标记，对“秋光”//“绿稻”/“秋光”回交群体进行了全基因组分析。两个控制杂种花粉不育的基因座，分别命名为S33(t)和S34(t)，位于第3和第11染色体上。这两个基因座推测与所有先前报道的配子体基因和杂种花粉不育基因座都不同。两个基因座上“绿稻”和“秋光”等位基因之间的相互作用导致携带“绿稻”等位基因的花粉育性降低。为了定位主基因座S33(t)的精确位置，我们从回交群体中选择了165株花粉育性高于80.0%的植株，并使用新开发的SSR标记分析了S33(t)基因座周围的重组事件。S33(t)被定位在SSR标记RM15621和RM15627之间的86 kb区域内。对该区域的序列分析表明有10个开放阅读框。这些结果对于克隆该基因以及在水稻育种计划中进行相应中性等位基因的分子标记辅助转移具有重要价值。此外，还讨论了杂草稻株系“绿稻”的起源。
