Chitinase Genes And The Bivalent Insect-resistant Genes Agrobacterium-mediated Transformation Of Wheat And Cotton Genetic Research

Study on Agrobacteriwn Twnefacien-mediatedChitinase and scorpin venoingene genesTransforxnation of Wheat and Cotton Abstract Wheat and cotton are important grain and economic crops respectively. But their production and qualities are severely affected by diseases and pests. It is a key program to quicken the breeding procedures of disease and pest resistant cultivars with high qualities in farming. Chitinase gene, chitinase gene + scorpin venom gene were transformed into wheat and cotton by Agrobacterium twnefacien in this research. And further more, some factors and conditions, which affect the transformation efficiency, were also investigated. These included genotypes, different morphogeneses and numbers of subculture of embryogentic calli, the antibiotic concentration, and the employment of AS, etc. The results showed as follows: Callus frequencies of wheat immature embryos and plant regeneration were all affected by genotypes. Of 10 wheat cultivars we selected, 99023 showed the highest callus frequency and regeneration rate (99.5% and 87.5% respectively). Wheat embryogenitic calli with short terms of subculture which were cream-colored, slight yellow, fresh, fragile and vigorous exhibited strong differentiation capacity (91.7%) and high regeneration rate (75%). AS is one of the factors affecting wheat transformation. When AS (SOmg/L) was added into YEB culture medium and co-culture medium, the ratio of induced j~r ~istant calli was the highest (84.4%). By screening using 25O mgfL Kin, 36 resistant plants were obtained and their molecular assays are being conducted. There is little effects of cotton's genotypes on resistant embryogenitic calli, whereas the transformation rate in hypocotyes of explants (45o/47%) is clearly higher than that from leafstalks (30o/o 34%). During the transformation, if the concentration of Hyg is 5 Omg/L, it was helpful for the induction of resistant embryogentic calli. And there was no effect of AS on cotton transformation rate. Our further molecular assays on resistant plants and calli are also being conducted. The optimized technology of Agrobacterium twnefacien mediated transformation to wheat and cotton cultivars in our institute will be used as a reference for crop transformation, such as wheat, cotton, etc.