玉米雄性不育突变体ms1153的遗传分析与基因定位

以玉米雄性不育突变体ms1153为材料,通过减数分裂期花粉母细胞染色体观察和不同发育时期花药石蜡切片分析突变体不育表型产生的原因,利用F₁和F₂群体确定突变体MS1153的遗传方式和基因ms1153物理位置。结果表明,与野生型相比,突变体植株在营养生长期无明显差异,在生殖生长阶段花药不能从颖壳外露,成熟花粉粒内无淀粉积累。细胞学分析发现,突变体减数分裂过程正常,但减数分裂后绒毡层降解推迟。遗传分析表明,突变体ms1153的不育性状受1对隐性核基因控制。利用图位克隆的策略将MS1153基因定位于玉米第4染色体分子标记8243与8275之间,物理区间为221.4~226.2 Mb,此区间内没有已克隆雄性育性基因,说明MS1153是一个新的玉米雄性育性基因。

Genetic Analysis and Gene Mapping of the Male Sterile Mutant ms1153 in Maize

Using the male sterile mutant ms1153 as the material, the cause of the male sterile phenotype in the mutant were analyzed by the observation of chromosomal behavior and paraffin section of anthers during different stages. The genetic mode of ms1153 and the physical location of MS1153 were determined with F₁ and F₂ population. Compared with wild type, ms1153 plants had no obvious difference in vegetative growth stage. However, in reproductive growth stage, ms1153 anthers could not emerge from the glume and the accumulation of the starch in the mature pollen grains were disappeared. Cytological analysis revealed that the meiotic process was normal and the degradation of tapetal cells was delayed in the mutant. Genetic analysis showed that the ms1153 male sterility was controlled by a single recessive gene. In addition, MS1153 gene was located between molecular markers 8243 and 8275 on the chromosome 4 through the map-based cloning, with a physical interval of 221.4-226.2 Mb. Furthermore, no male fertility genes were reported in this region, indicating that MS1153 is a novel gene regulating male fertility formation in maize.