水稻胚乳突变体cse-2的表型分析及基因定位

Phenotypic Analysis and Gene Mapping of Rice Mutant Chalkiness and Shrunken Endosperm-2

淀粉是水稻籽粒中含量最多的大分子物质,其组分及含量对于稻米的各项品质指标均有直接影响。本研究鉴定了1个新的粉质胚乳突变体(chalkiness and shrunken endosperm-2,cse-2),分析了突变体的农艺和品质相关性状,并对其开展了基因定位。结果表明,与野生型相比,突变体的株高、穗粒数和结实率等农艺性状以及淀粉含量、淀粉组分比例、淀粉粒形态结构、蛋白质含量、脂肪酸含量等品质性状均发生了显著变化。遗传分析表明,突变性状是由位于4号染色体上的1对隐性核基因控制。序列分析表明,精细定位区间内LOC_Os04g55230/FLO2基因第6064位碱基胞嘧啶(C)突变为胸腺嘧啶(T),形成TAA无义突变。以上结果证明,cse-2是已报道突变体flo2的一个新等位突变体。

Starch is the most abundant macromolecular substance in rice grain,and its composition and content have direct effect on quality indexes of rice.In this paper,agronomic and qualitative traits related to chalkiness and shrunken endosperm-2(cse-2)were investigated and the candidate gene was mapped.The results showed that the agronomic traits including plant height,grain number per panicle,seed-setting rate,starch content and its components,physicochemical properties,starch grain morphology and structure,protein and fatty acid contents of the mutant had significantly altered.Mapping result showed that mutated phenotype is determined by a pair of nuclear recessive genes locating on chromosome 4.Sequence analysis indicated that a single nucleotide substitution of C-to-T occurred on the 6064^(th) base of LOC_Os04g55230/FLO2,forming a TAA nonsense mutation.Therefore,cse-2 was a new allelic mutant of flo2.