小麦优质Ax1/Ax2*和Dx5亚基的二重AS-PCR分子鉴定

为了提高小麦Glu-A1位点Ax1/Ax2*亚基和Glu-D1位点Dx5亚基分子标记鉴定效率，方便小麦分子水平的辅助选择及品种评价，建立了小麦高分子量谷蛋白Ax1/Ax2*亚基及Dx5亚基基因的二重AS-PCR反应体系。结果表明，PCR鉴定结果与SDS-PAGE电泳结果一致。利用建立的二重AS-PCR稳定扩增体系鉴定了21份外引小麦品种系的谷蛋白Glu-A1及Glu-D1位点，有7个品种扩增出1500 bp特异片段，表明具有Ax1/Ax2*亚基；有11个品种扩增出478 bp特异片段，表明具有Dx5亚基；小麦优质Ax1/Ax2*亚基和Dx5亚基出现百分率分别为33.3%和52.4%。该反应体系扩增稳定，可同时鉴定Ax1/Ax2*亚基及Dx5亚基，适用于优质小麦新品种的辅助选择。

Identification of Ax1/Ax2* and Dx5 Subunit of Wheat HMW Glutenin By Duplex AS-PCR

It has been demonstrated that Ax1/Ax2* and Dx5 are normally associated with wheat flour superior end-use quality, especially dough strength. This paper was designed to improve the molecular marker identification efficiency by the duplex allele-specific polymerase chain reaction (Duplex AS-PCR). In distinguishing the high molecular weight glutenin subunit, the results of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) proved that the established duplex AS-PCR was credible. The genes of Ax1/Ax2* and Dx5 could be identified simultaneously in this polymerase chain reaction system. The presence of 1500 bp and 478 bp bands showed Ax1/Ax2* and Dx5 genes, respectively. A total of 21 wheat cultivars abroad were tested by the duplex allele-specific PCR-based assay and the frequencies of Ax1/Ax2* and Dx5 were 33.3% and 52.4%, respectively. In conclusion, the amplification reaction system was stable, and it could be used to simultaneously identify Ax1/Ax2* and Dx5 subunits, so it would be very helpful for marker-assisted selection of new wheat varieties with high quality.