中文摘要：

稻穗小穗梗的发育与产量有着密切关系。文章利用60Coγ射线辐照籼稻品种＂浙农7号＂,获得一个性状能稳定遗传的小穗梗弯曲突变体bpb1（bent pedicel branch 1）,表现为小穗梗弯曲,并伴有小穗梗长度增长、穗长缩短和植株矮化等特点。扫描电镜观察显示,bpb1突变体小穗梗的表皮毛及气孔变小,外表皮细胞和厚壁细胞排列不规则,接近弯曲部位的细胞变小、排列更为紧密。bpb1突变体小穗梗横切面观察表明,小维管束排列结构发生明显变化。遗传分析表明该突变表型受隐性单基因控制。利用bpb1突变体与粳稻品种＂浙农大104＂杂交构建的F2群体进行基因定位,将bpb1基因定位于水稻第7号染色体长臂SSR标记RM21537和RM21552之间,该区间的物理距离为343 kb,该区域内未发现与水稻小穗梗发育相关的已知基因。文章为bpb1基因的克隆和功能研究奠定了重要基础。

英文摘要：

Rice pedicels are tightly associated with the yield of grain. In the present study, a novel and stable pedicel mutant bpbl （bent pedicel branch 1） was obtained from the wild type ＂Zhenong 7＂ after 60Co T-ray treatment. The mutant had the typical phenotype of bent pedicel branches with multiple abnormal phenotypes, such as longer pedicels, short panicles, and dwarfism. Detail examination using scanning electron microscopy revealed that the pedicel epidermal hairs and stomas in the mutant were smaller than those in the wild type. The epidermal and sclerenchymatous cells were arranged irregularly, and the cells in the bend region of pedicels became smaller and arranged closely. The transverse observation of the mutant pedicel branches showed that the small vascular bundles arranged differently from those of the wild type. Genetic analysis indicated that the abnormal phenotypes were controlled by a single recessive gene. Using the F2 mapping population from the bpbl mutant crossed with the japonica rice variety ＂Zhenongda 104＂, the bpbI gene was mapped in a 343 kb region between two SSR markers, RM21537 and RM21552, at the long arm of chromosome 7. Because no homologous gene was found in this region until now, bpbl might be a novel gene related to the pedicel development and growth. This study could be beneficial to future cloning and functional analysis of the bpbl gene.