Abstract: Effects of receptor varieties, plasmids concentrations on the rice transformation rate via floral organ-mediated method were studied. Of 20 tested rice varieties, nine varieties were suitable for transformation. The feasible plasmids concentrations for rice transformation varied with receptor varieties in a rather wide range of concentrations. The validity of target genes transferred by rice floral organ-mediated method were verified by PCR analysis, evaluation of resistance to sheath blight and blast, screening by hygromycin B and examination of GUS activity in transgenic rice. T₄ transgenic rice plants containing Serratia marcescens chitinase gene showed resistance to rice sheath blight and rice leaf blast after inoculation with pathogens.

Key words: rice, gene transfer, chitinase gene, disease resistance

摘要： 研究和分析了受体品种、质粒浓度对水稻花器介导法转化的影响。供试的20个水稻品种（系）中有9个适用于质粒转化,不同受体品种要求的质粒适宜浓度不同。经潮霉素（hygromycin）筛选、PCR分析、抗稻纹枯病和稻瘟病鉴定、GUS活性检测转基因水稻后代，验证了水稻花器介导法转目标基因的有效性。获得了含细菌几丁质酶基因的优丰162转基因T4 代，它表现出对叶瘟病和纹枯病抗性有明显提高。

关键词: 水稻, 转基因, 几丁质酶基因, 抗病性