The P_SAG12-IPT Gene Transformation Wheat And The Effects Of Agrobacteria On The Wheat Seed-Setting And Seed Germination

Huanghuai region is the major wheat production area China, which plays a vital role in our country's food security. Using new high-yield varieties was the most economical and feasible way to increase wheat yield. Leaf senescence was one of the important factors in restricting the elevation of wheat yield. The grain yield of wheat could be increased significantly through raising photosynthetic efficiency and postponing the senescence of leaf. Gene IPT could synthesize and accumulate cytokinin, which could delay the senescence of plants. In this experiment, the pollen tube pathway was used to transform PSAG12-IPT into main wheat varieties of Huanghuai region in order to create new transgenic plants of wheat; And the effect of soaking of flower in agrobacterium on the wheat seed-setting and germination of seeds were studied, which could provide a reference for creating the genetic transformation system of wheat and the other plants by agrobacterium tumefaciens and improving the efficiency of transformation. The main results were as follows:(1)The pollen tube pathway were used to transform with Xinong979,Xinong889 and Zhengmai9023 as materials. 2 strains of Xinong979 and 5 strains of Xinong889 were positive via PCR detection, which proved target gene PSAG12-IPT with specific promoter had been introduced into wheat genomes. The analysis of aging process and agronomic traits showed that PSAG12-IPT could be specifically expressed in the aging leaf of 4 transgenic wheat plants that were 1 strain of Xinong979 and 3 strains of Xinong889, and the leaf senescence had been significantly improved. The transformation efficiency of Xinong889 was higher, and there was none transgenic plants of Zhengmai9023.(2)With the wheat varieties of Zheng9023, Xinong889, Xinong979 as the dominated factors, the agrobacterium density of 0, 0.5, 1.0 and 1.5 OD as the deputy factors, the effect of agrobacterium floral dip on the wheat seed-setting and germination of seeds were studied by resplit-plot design. The results showed that the interaction effects of species and agrobacterium density on the wheat seed-setting rate, thousand-grain weight, seed germination rate, seedling height, seedling fresh weight, seedling dry weight, seedling root length, Chlorophyll content, MDA content, POD, SOD activity and Kanamhycin resistant plants rate were not significant. With the agrobacterium density increased, the seed-setting rate, seed germination rate, seedling height, seedling fresh weigh, seedling dry weight, seedling root length, Chlorophyll content, POD and SOD of different species were decreased, MDA and Kanamycin resistant plants rate were increased, and the effects of agrobacterium were differences among wheat varieties. The most appropriate density of agrobacterium might be 1.0-1.5 OD according to the composite results.