水稻颖花畸形突变体(gm(t))的遗传分析与基因定位

Genetic Analysis and Gene Mapping of Glume Malformation Mutant(gm(t)) in Rice

在籼稻‘绵恢523’בR8117’的F5世代15C197群体分离出颖花变异突变体,表现为内稃退化、发育迟缓或发育成外稃状、颖壳畸形不闭合,暂命名为颖花畸形突变体(glume malformation,(gm(t))。以该突变体gm(t)与粳稻02428杂交构建F2定位群体,利用图位克隆技术对gm(t)进行初步定位。结果表明gm(t)突变体的颖花畸形性状受单隐性核基因控制,初步将gm(t)定位在水稻第6号染色体上,标记ZM506 (1.254 Mb)与RM3463(2.110 Mb)之间,两个标记间的物理距离约为856 kb。检索该区间发现含有内颖形成调控基因DP1(LOCOs06g04540)。gm(t)的穗部表型与dp1突变体很相似。为此,对15C197野生型和gm(t)突变体的DP1基因进行比较分析,发现gm(t)突变体在该基因编码区有一段19 bp的缺失,会引起移码突变。因此推测gm(t)即为DP1基因的等位突变基因。gm(t)为研究水稻外轮花器官发育特性及相互转换的内在分子机制提供新的种质资源。

The variant mutant of glume was isolated from F5 generation 15 C197 population of nonglutinous rice’Mianhui 523’×’R8117’, which showed palea degeneration, growth retardation or lemma shape growth, the glume malformation was not closed. It is temporarily named the glume malformation(gm(t)). gm(t) was hybridized with japonica rice 02428 to construct F2 location population, and it was preliminarily localized by map cloning technology. Results showed that the glume malformation phenotypeof of gm(t) mutant were controlled by single recessive nuclear gene. gm(t) was preliminarily located on chromosome 6 between markers ZM506(1.254 Mb)and RM3463(2.110 Mb), the physical distance between two markers was about 856 kb. The interval was searched to find the regulation gene DP1(LOCOs06 g04540) contains formation of the inner glume. and the flower phenotype of gm(t) was similar to the dp1 mutant. To this end, we made comparative analysis on DP1 gene of 15 C197 wild type and gm(t) mutant. It was found that the gm(t) mutant had a deletion of 19 bp in the coding region, which could cause frameshift mutation. Therefore, it was suggested that gm(t) was allelic mutant gene of DP1 gene. gm(t)provides a new germplasm resource for studying the developmental characteristics of rice outer-ring floral organs and the internal molecular mechanism of mutual transformation.