Abstract: PCR and Southern blot analysis indicated that mtlD gene had been integrated into the rice genome mediated by Agrobacterium tumefaciens LBA4404 (pBIM). mtlD gene segragated in T₁ generation and pure transgenic lines appeared in T₂ generation. The expression of the mtlD gene in transgenic plants was demonstrated by enzymatic activity assay. Under 0.75% NaCl stress, the relative electronic conductivity and membrane permeability were detected in T₃ transgenic plants of 7 different lines. Results showed that the damage to membrane structure of the transgenic plant was lower than that of their controls. Some transgenic plant lines could grow normally under 1.0% NaCl stress whereas the controls could not grow and died after 2 weeks under the same environment. Through sexual hybridization, rice plants with mtlD gene and gutD gene were got, some of them could grow normally under the stress of 1.25% NaCl.

Key words: rice, mtlD gene, gutD gene, transgenic plant, salt tolerance, sexual hybridization

摘要： 摘要：PCR和Southern blotting检测表明，来自大肠杆菌的[i]mtlD[/i]基因已通过农杆菌介导整合进水稻基因组。[i]mtlD[/i]基因在T1代出现分离, T2代出现纯系。在0.75% NaCl胁迫下，7个转基因T3代株系都能检测到mtlD酶活性，与对照相比细胞膜的相对电导率和大分子渗漏值明显降低。部分转基因株系能在 1.0% NaCl浓度下正常生长，而对照在0.5% NaCl浓度下已不能存活。通过有性杂交途径实现了[i]mtlD[/i]和[i]gutD[/i]两个基因的聚合，部分杂交后代株系能在1.25%NaCl胁迫下正常生长结实。

关键词: 水稻, 1-磷酸甘露醇脱氢酶基因, 6-磷酸山梨醇脱氢酶基因, 转基因植株, 耐盐性, 有性杂交