水稻雄性核不育突变体ms7的遗传分析及基因定位

【目的】通过对水稻雄性不育突变体的研究,可以鉴定更多与育性或花粉发育相关的基因,有助于解析水稻雄性生殖发育的整个调控网络。【方法】常规种植条件下,突变体ms7 (male sterile 7)与对照种植于浙江富阳和海南陵水,比较它们的育性及主要农艺性状差异,利用混池关联分析和图位克隆方法进行目标基因定位。【结果】整个生育期,突变体ms7生长速率与野生型一致,成熟期的株高、分蘖数、叶数、叶大小、穗长和每穗颖花数等性状与野生型相比也没有显著差异,但ms7结实率为0,表现为完全雄性不育,花药瘦小且颜色发白,半薄切片显示绒毡层降解推迟,花粉镜检呈染败。遗传分析表明花粉败育受单个隐性基因控制,定位于第7染色体上BSA11与YD7045之间1.17 Mb的范围内。【结论】本研究为水稻雄性不育基因ms7的克隆和功能研究打下了基础。

Genetic Analysis and Gene Mapping of a Male Sterile Mutant ms7 in Rice

【Objective】Genes related to pollen development and fertility can be identified through the study on male sterile mutants, which is helpful to analyze the whole regulatory network of male reproductive development in rice. 【Method】The fertility and agronomic traits of the ms7 (male sterile 7) mutant and its wild type were compared under conventional planting conditions in Fuyang, Zhejiang and Lingshui, Hainan. The sterile gene was mapped by bulked segregant analysis and map-based cloning.【Result】During the whole growth period, the growth rate of ms7 mutant was the same as that of wild type, and there was no significant difference in plant height, tiller number, leaf number, leaf size, panicle length and spikelets per panicle between ms7 and its wild type. However, ms7 exhibited slender and white anthers with inactive pollen grains which couldn’t be stained with I₂-KI, and no seeds were produced. Observation results of anther cross-sections exhibited that tapetum programmed cell death (PCD) was delayed. Genetic analysis showed that pollen abortion was controlled by a single recessive nuclear gene, which was mapped to a 1.17 Mb region between BSA11 and YD7045 on chromosome 7. 【Conclusion】It will contribute to the further molecular cloning and functional analysis of male sterile gene ms7 in rice.