Abstract: Forty-one homozygous rice lines transferred with chitinase gene (RC24) and β-1,3-glucanse gene(β-1,3-Glu)were selected to study on their resistance to sheath blight. The resistance of transgenic lines had significant differences, and according to t he result of cluster analysis, they could be divided into resistant, moderately resistant, moderately susceptible and susceptible types, but 92.1% of them belonged to the type of moderately resistant or moderately susceptible. For diffe rent resistant or susceptible type lines, rice sheath blight resistance was significant correlated with the chitinase activity of transgenic lines except resistant type lines, in which enzyme activity coded by target gene was lower than that of moderately resistant type. The chitinase activity of transgenic lines at different time after inoculation or different parts of the same plant were alike, which suggested that the expression of chitinase gene was constitutive. Check varieties’chitinase activity would chang e at different time after inoculation and reach a peak at sometime, but it had n o differences at different parts of the same plant.

Key words: rice, transgenic lines, sheath blight, resistance to disease, cluster analysis, chitinase activity

摘要： 对通过基因枪转化获得的41个转水稻碱性几丁质酶和苜蓿β-1，3-葡聚糖酶基因（RC24和β-1，3-Glu）的高世代纯合株系进行纹枯病抗性接菌鉴定，结果表明不同转基因系间抗性存在极显著差异，聚类分析可分为抗、中抗、中感、感病四种类型，但其中92.1%的株系属中抗或中感类型；选择不同抗感类型的代表性株系，测定其几丁质酶活力，结果显示中抗、中感、感病类型转基因株系表达的几丁质酶活力与其纹枯病抗性表现呈现一致性，而抗病类型表达目标基因编码的酶活力低于中抗类型；接菌诱导后，在不同时间或同一植株的不同部位检测，转基因系的几丁质酶活力因其组成性表达而无明显差异，而未转基因的对照品种在诱导后不同时间其几丁质酶活力表达呈“峰”式曲线分布，同一植株不同空间位置的酶活力却无明显差异。

关键词: 水稻, 转基因系, 纹枯病, 抗病性, 聚类分析, 几丁质酶活力