优质杂交粳稻滇禾优34香味产生的分子基础

The Molecular Basis of Rice Fragrance in the High Quality Japonica Hybrid Rice Variety Dianheyou34

【目的】通过对杂交粳稻滇禾优34香味的分子基础进行研究,为选育有香味的杂交粳稻新品种奠定理论基础。【方法】对滇禾优34的母本不育系H479A和父本恢复系南34中的与香味相关的甜菜碱脱氢酶基因Osbadh2-E7进行克隆分析;利用KOH浸泡法对滇禾优34的F2代群体叶片进行香味表型鉴定,并利用Osbadh2-E7等位基因特异引物对滇禾优34的F2代群体进行基因型鉴定。【结果】南34中的OsBADH2基因可表达1个正常、有功能的甜菜碱脱氢酶蛋白,而在H479A中是1个典型的、广泛存在于香稻品种中的功能缺陷突变型基因Osbadh2-E7。对滇禾优34的F2群体植株香味的表型鉴定表明:有香味的植株占总株数的31.8%,χ^2检验表明:无香与香味植株符合1对基因控制的3∶1的分离比例,且有香味为隐性。利用Osbadh2-E7等位基因的特异分子标记对F2群体基因型鉴定结果表明:23.1%的杂合基因型植株也会产生香味。【结论】由于H479A中的Osbadh2-E7突变等位基因,导致滇禾优34种植生产的籽粒中有1/4的籽粒是纯合突变基因型,从而使食用的稻米产生香味。除此之外,F2群体中部分杂合基因型的籽粒也可能产生香味,对这些籽粒产生香味的机制有待于更深入的研究。

[Purposes]It is important to clarifying the molecular mechanism of the aroma in hybrid rice for selecting new varieties with this high value trait,a japonica hybrid rice variety Dianheyou34 with aromatic character was used to study the aromatic genetic pattern in hybrid rice.[Methods]The betaine aldehyde dehydrogenase gene,OsBADH2 which is the main factor control the fragrance in rice were cloned in the two parents of japonica hybrid rice Dianheyou34,the cytoplasmic male sterile(CMS)line H479A and the restorer line Nan34;the aroma of the leave from the F2 population which came from Dianheyou34 was checked by KOH soaked method,and the genotype of all plants were identified by a Osbadh2-E7 alleles specific molecular marks.[Results]The OsBADH2 of Nan34 was a wild type allele which could express an intact functional betaine aldehyde dehydrogenase,in contrast the allele in the CMS line H479A was a typical mutational one,Osbadh2-E7 which exits in most aromatic germplasm,expressed a loss of functional protein.The results of the phenotypic identification in the F2 population showed that there were 31.8%of plants be aromatic,χ^2 test showed that segregation ratio between aromatic and no-aromatic plants accord with the one pair genes controlled rule,3:1,and the aromatic trait was recessive.Based on the results of the genotype,besides the pure mutation plants,there were 23.1%of total heterozygous plants be aromatic.[Conclusion]Because of the mutational allele Osbadh2-E7 in the CMS line H479A,there were a quarter pure mutational genotype grains in the F2 population which yield in the Dianheyou34 production fields production,that led the cooked rice with fragrance.Except for this,there were also parts of heterozygous grains could produce aroma,but the mechanism needs more research.