Studies On The Pure Line Identification And The Dough's Viscoelastic Of Transgenic Wheat

HMW-GS(High molecular weight glutenin subunits) play a major role in the malleability of wheat gluten. There are three genome of wheat: 1A, 1B and 1D, encoding1Ax-type subunit, 1Bx- and 1By-type subunits and 1Dx- and 1Dy-type subunits,respectively. Different subunits have different effect on the malleability of wheatdough.1Ax1, 1Dx5+1Dy10, 1Bx17+1By18 have been proved to be the subunits with high quality.Combining the transgenic technique with conventional crossing, we developed the introgression lines, overexpressing the exogenous HMW-GS 1Ax1 and exogenous HMW-GS 1Dx5, respectively. We selected and identified the introgression lines thoughtfully, using SDS-PAGE(sodium dodecyl sulfate polyacrylamide gel electrophoresis),and then fulfilled the sequent mixing experiments.After classification, there are fifteen transgenic types and nine wide types. The whole twenty four types were developed by selfing and backcrossing breeding technique. The exogenous genes 1Ax1 and 1Dx5 were transformed into the respective acceptors, with the overexpressing transgenic wheat lines developed.The quantities of each type were very different. So I only chose seven transgenic types and five wide types to do the mixing experiments due to the restriction of the quantity. Comparing the mixing properties between each type to verify the different affections of HMW-GS during the procession of kneading dough, it was concluded that the subunit type which was combined with 1Dx5+1Dy10, 1Bx17+1By18 and overexpression of 1Ax1 was the best. Meanwhile, it was found that the proportion of xand y-type subunits also could affect the mixing properties though the comparison.The quality of the wheat seeds wound descend after being stored for many years. So I made the propagation of seeds for twice times, in order to conserve seeds and increase the quantity. At the first,the propagation undertook in the greenhouse, because it could avoid the limitation of weather and the main reason was that some types were too few to plant in the field. After the preliminary propagation, I got enough seeds to continue the field propagation. In May, I harvested the wheats and had already finished breed conservation.