人工合成小麦与普通小麦杂交后代衍生群体的Rht8基因分析

Genetic Performance of Dwarfing Gene Rht8 in Synthetic Hexaploid Wheat-Derived Populations

【目的】四倍体小麦与节节麦杂交培育的人工合成小麦已广泛应用于国内外小麦品种改良。通过研究人工合成小麦与普通小麦杂交后代的Rht8基因型,有助于提高分子标记育种效率,也有助于Rht8基因型的多态性研究,并为人工合成小麦在中国小麦品种改良和分子标记育种中的应用提供依据和方法;【方法】以引自CIMMYT的人工合成小麦分别与中国四川成都平原主栽普通小麦品种杂交、回交的BC2F2:6后代群体中选育的113份优良高代系和川麦38、川麦42、川麦43和川麦47育成品种为材料,采用特异引物的PCR扩增和改进的聚丙烯酰胺凝胶电泳对其Rht8基因型进行了研究;【结果】在以syn768、Syn769、Syn780和Syn786人工合成小麦为亲本的117份后代衍生群体检测材料中,Rht8基因型频率为77.78%。从每一个人工合成小麦形成的小的后代衍生群体看,Rht8基因型频率各不相同。以syn768为亲本的后代衍生群体,Rht8基因型频率最高,为96.70%;在以syn769为亲本而育成的优良高代系和川麦38、川麦42与川麦43育成品种中,Rht8基因型频率最低,为71.64%;以Syn780为亲本的后代衍生群体中,Rht8基因型频率为73.68%,分离比率约为3:1;以Syn786为亲本育成的材料只有川麦47,该品种不含有Rht8该基因;【结论】不论父本或母本的Rht8的基因型状况如何,它们所产生的杂交后代材料Rht8基因的遗传是随机的。

[OBJECTIVE]Synthetic hexaploid wheats obtained by crossing Aegilops tauschii Coss. （DD） with tetraploid wheats （AABB）, containing genetic variability not found in hexaploid wheats, have been widely used for genetic improvement of common wheat. Understanding the distribution of Rht8 gene in synthetic hexaploid wheats × common wheat （Triticum aestivum.L） will be crucial for yield improvement; [METHOD] A total of 113 lines from BC2F2：6 three CIMMYT lines and four commercial cuhivars by synthetic hexaploid wheats × common wheat crosses were used to detect Rht8 genotype by specific-primer PCR amplification and modified PAGE; [RESULTS]The frequency of Rht8 genotype is 77.78% in the detected derivedpopulations from syn768, syn769, syn780 and syn786 lines. But as for every population from syn768, syn769 and syn780 lines, It was concluded that the frequency is not the same. The frequency of Rht8 genotype of the population from syn768 is 96.70% as the highest one, and the one from syn769 with 71.64% is the lowest, and for the population from syn780, its frequency of Rht8 genotype is 73.68% with a close ratio of 3：1 and the cultivar Chuanmai 47 from syn786 is absent from the gene Rht8 ; [CONCLUSION]The inheritance of the dwarfing gene Rht8 is randomly separated, and the study on Rht8 genotype of progeny from crosses of synthetic hexaploid wheat and common wheat can provide useful information for improving common wheat and introducing cultivars from CIMMYT, and facilitating the analysis of Rht8 genotype polymorphism.