Study On Developing And Application Of Herbicide-resistant Rice(Oryza Sativa L)

Rice is the staple food in China and in the whole world, about half people in the world live on the rice. In China, the growing area, total yield, and yield per unit area are in the primacy comparing with other cereal grains. However, the natural weed induce much loss of the rice's yield, it causes more than 10 million tons loss every year. More ever, in order to treat the weed, the use of herbicide has polluted the environment seriously. Along with the planting of the herbicide-resistant crops, like herbicide-resistant soybean, herbicide-resistant maize and rape, consumption of herbicide decrease greatly. Herbicide-resistant crops proved that they have some advantage comparing with common varieties, and it will be a effective measure to control the weed in the paddy field by using plant gene engineering to breed herbicide-resistant new rice varieties.This research was about producing herbicide-resistant rice transgenic plant by transferring different plasmids into relevant embryonic callus mediated by Agrobacterium tumefaciens EHA105 .These embryonic callus were derived from mature embryos of Indica rice and japonica rice. And the phosphinothricinacetyl transferase gene (bar) has repellence to phosphinothricin (PPT) and the EPSPS gene which is synthesized artificially has repellence to glyphosate and the two genes were interest gene there. And different plasmids were designed in vitro, interest genes bar and EPSPS are constructed in T-DNA fragment, respectively. The research included the experiments of breeding herbicide-resistant rice by hybridizing existing herbicide-resistant rice with common rice variety.1. bar gene and EPSPS gene are successfully transferred into rice embryonic callus derived from mature embryos of Indica rice, 2354, Minghui63 and japonica rice, Zhonghual 1. About 30 transgenic seedlings of indica variety 2354 were regenerated. 45 transgenic seedlings of indica variety Minghui63 were regenerated and 207 transgenic seedlings of japonica rice variety, Zhonghual 1 were regenerated.2. PCR analyses, field testing, and Southern blot indicated that bar gene has been translated into the rice genome, most of them are single-copy. And the artificial synthesized CP4EPSPS gene showed the herbicide-resistant. The glyphosate-resistant transgenic rice was developed firstly by using the gene of CP4EPSPS.3. The main agronomic characters of new variety of herbicide-resistant compared with the original variety showed that several breeding lines for herbicide (Basta) resistance from DaHua 25 and MingHui 63 were developed through the back-cross. Back-cross method was an effective way to develop the herbicide-resistant rice.4. The results of the experiment of spraying different herbicide concentration on the rice during different period indicated that 0.17-0.13% of 15% Basta was the effective concentration for controlling the weed and improvement of rice yield.5. The results of the experiment of herbicide handle for increasing the purity of hybrid seeds showed that 0.17% of 15% Basta could make 100 percent of the purity through spraying in 3-leaf stage, which confirmed that the herbicide-resistant genes in applying in hybrid rice breeding was effective.