论文部分内容阅读
水稻的穗是一个典型的圆锥花序,其发育形态直接影响水稻产量。本研究利用本课题组创建的水稻“中花11号”T-DNA插入突变体库,通过表型筛选鉴定了一个稀穗突变体。该突变体在营养生长阶段表现为分蘖数减少,生殖生长阶段稻穗一次枝梗发育正常、但二次枝梗数和侧生小穗数目显著减少,表现为明显的稀穗表型。分子检测结果表明该突变体不是由T-DNA插入导致的。通过与籼稻品种“珍汕97”构建F2遗传定位群体遗传分析表明:该突变性状受一个隐性基因所控制。采用图位克隆的方法将目标基因定位于4号染色体上的SSR标记RM16880和RM1205之间约120 kb范围内。基因组序列分析表明:该突变体是由于LAX2基因序列缺失60 bp所导致。该突变体是LAX2的一个新的等位突变体,命名为lax2-4。lax2-4为研究LAX2控制水稻穗形态建成的分子机制积累了遗传材料。
Rice panicle is a typical panicle, its developmental morphology directly affects rice yield. In this study, we used a T-DNA insertion mutant library of rice “Zhonghua 11” created by our group to identify a spike mutant by phenotyping. The mutant showed reduced number of tillers at vegetative growth stage, and primary branchlets developed normally at reproductive stage. However, the numbers of secondary branches and lateral spikes were significantly decreased, showing obvious spike phenotype. Molecular testing indicated that the mutant was not caused by T-DNA insertion. The genetic analysis of F2 locus based on indica variety “Zhenshan 97” showed that this mutant trait was controlled by a recessive gene. Using the map-based cloning method, the target gene was located in the range of about 120 kb between the SSR markers RM16880 and RM1205 on chromosome 4. Genomic sequence analysis showed that the mutant was caused by the deletion of LAX2 gene sequence of 60 bp. This mutant is a new allelic mutant of LAX2, designated lax2-4. lax2-4 accumulated genetic material for studying the molecular mechanism of LAX2 control of rice panicle morphology.