Introducing Of Antisense-waxy Gene Into Maintainer Line Of Indica Hybrid Rice Through Agrobacterium-mediated Transformation

Rice is one of the main food crops in the world. However, at present the quality of most rice varieties in china, especially indcia varieties, are poor relatively .A main reason of which is higher amylose content. So, rice breeders always expect to find a way to improve rice quality by decreasing amylose content properly.With rapid development of molecular biology and genetic engineering, it has been possible to improve rice starch quality by genetic engineering. There are many advantages of Agrobacterium-mediated transformation, such as convenience in manipulation, high transformation efficiency, low copy number of introduced genes and simple integration pattern, so is widely utilized by plant transgene workers. In this paper, the antisense waxy gene has been transfered into indica maintainer lines through Agrobacterium-medialed transformation in order to reduce amylose content of the receptor varieties properly and then improve their rice quality. The major results were as follows:1. By screening and optimizing such factors that may effect Agrobacterium infection efficiency like tissue-culture system, physiological condition of calli, Agrobacterium suspension medium composition, Agrobacterium solution concentration, co-cultivation duration and so on, a high-efficiency system of Agrobacterium-me-diated transformation for D62B was established.2. Some transgenic plants by transformation with antisense waxy gene resisted hygromicine were obtained. PCR analysis showed that the selective marker gene and foreign target gene had been tranfered into the genomics of most transgenic plants.3. The T1 progenies of transgenic lines were analyzed genetically. The results showed that most of the TO self-crossing seeds could grow normally and had hgyromicine resistance. Hgyromicine resistance of the TI progenies segregated in accordance with Mendel's single gene inheritance rule.4. Amylose content in the endosperm of mature seeds was measured. The results showed amylose content of the untransformed parent D62B was 25.1%, then that of one tested TO transgenic plant was 20.3%, which was 19.1% lower than that of theuntransformed parent.