Backcross Breeding And Homogenization Screening Of Aphid Resistant Transgenic Wheat With Cytoplasmic Inheritance

Wheat is an important food crop in China,which is widely planted all over the world.However,aphids often pose a serious threat to the yield and quality of wheat.Chemical control is a common method to control aphid damage.However,excessive use of pesticides will lead to serious environmental pollution and affect human health.It is expected to reduce the use of chemicals and increase the yield of wheat by transgenic technology.In this study,the transgenic progeny materials obtained from the transformation of Pinellia pedatisecta agglutinin lectin gene(PPA)into shi-4185 wheat are taken as the research object.Based on the analysis of the existing position and genetic mode of the PPA gene,the transgenic wheat with cytoplasmic inheritance and high degree of homogeneity is obtained through backcross transformation and homogeneity screening.The main results of this research are as follows:Through the positive and negative cross experiments,it was found that the genetic mode of the target gene PPA in the transgenic wheat is both nuclear genetic mode and cytoplasmic inheritance mode.Through backcross,cross test,and PCR identification,a total of 27 better homozygous transgenic progeny materials are screened,that is,homozygous progeny without PPA gene in the nucleus and with cytoplasmic inheritance.Through PCR identification of the target gene,the results show that: after multiple generations of backcross,PPA gene still exists in transgenic wheat;through identification and analysis of homogeneity of backcross progeny,it shows that the aphid resistance of transgenic wheat progeny is different because of the different degree of homogeneity of the progeny,so the aphid resistance effect is not the same;different materials,different plants of the same material row,and the same row of different individual plants due to different degree of homogenization will lead to different aphid resistance.Among the 27 homozygous materials with cytoplasmic inheritance,9 materials with high degree of homomorphism are obtained by screening homomorphism,namely: 3-3-1,4-1-2,4-1-4,4-3-2,5-2-2,7-4-1,8-1-2,8-2-1,8-2-2,of which 8-2-2 had the highest aphid resistance efficiency,reaching 86.34%.No matter in the field or in the laboratory,transgenic wheat shows better resistance to aphids than wild-type wheat,indicating that this transgenic wheat is a good new material for wheat aphid resistance.