Expression of the 1Ax1 transgene in an elite Chinese wheat variety and its effect on functional properties.

BACKGROUND

The transfer of transgenes from 'model' wheat genotypes into elite wheat cultivars using conventional plant breeding is an alternative strategy for improving the dough quality of wheat. Thus a cross was made between a popular Chinese elite wheat cultivar of the Yangzi River down-central area that expresses high-molecular-weight glutenin subunit (HMW-GS): 1Bx7 + 1By8 plus 1Dx2 + 1Dy12, and a model transgenic wheat line B102-1-2 which over-expresses HMW-GS 1Ax1 in an L88-31 genetic background that includes HMW-GS 1Bx17 + By18.

RESULTS

F(1) to F(6) generations of crosses between B102-1-2 (paternal) and Emai (maternal) were analysed for their HMW-GS compositions, allowing the selection of pure F(6) lines over-expressing HMS-GS 1Ax1 in the presence of the endogenous HMW-GS: 1Bx7 + 1By8 with 1Dx2 + 1Dy12, and 1Bx17 + 1By18 with 1Dx2 + 1Dy12. Analysis of the F(6) lines showed changes in the extensograph parameters, with increases in peak area, resistance to extension, and extensibility and peak resistance to extension, similar to those observed in the transgenic paternal line B102-1-2.

CONCLUSION

This work showed that the expression levels of the 1Ax1 transgene and the effects on dough properties were similar in the transgenic parental line B102-1-2 and the F(6) progeny generated from a cross with an elite Chinese cultivar Emai. The feasibility of using transgenic lines expressing HMW-GS subunits in conventional breeding programmes was demonstrated.