Inheritance and Expression of Copies of Transgenes 1Dx5 and 1Ax1 in Elite Wheat (Triticum aestivum L.) Varieties Transferred from Transgenic Wheat through Conventional Crossing

To study the inheritance and expression of multiple copies of transgenes from transgenic wheat lines, three crosses between transgenic wheat lines B72-8-11b and B102-1-2 and Chinese elite wheat varieties Chuan89-107 and Emai18 were carried out. Chuan89-107×B72-8-11b, Chuan89-107×B102-1-2 and Emai18×B72-8-11b, and F₁ plants were selfed or backcrossed to obtain different generation populations. Protein analysis in grains of F₁ and F₂ and backcross progenies of BC₁F₁, BC₁F₂, BC₁F₃, BC₂F₁, BC₂F₂ and BC₂F₃ by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the transgenes 1Dx5 and 1Ax1 were expressed and segregated in the target wheat according to Mendelian laws. A range of 1Dx5 expression levels were observed in the progenies of Chuan89-107×B72-8-11b and Emai18×B72-8-11b, but the expression levels of 1Ax1 in progenies of Chuan89-107×B102-1-2 rarely changed. It suggested that the two foreign genes had different mechanisms of expression in the cross progeny, even though they were produced in the same way and the foreign 1Dx5 gene of 5–10 copies had the more complicated expression mechanism than the 1Ax1 gene of 4–5 copies.