水稻不同品种或组合对甲磺隆耐药性差异的机制研究

Study on the Mechanism of Different Tolerance of Various Rice Species or Combinations against Metsulfuron-methyl

以水稻乙酰乳酸合成酶 (AL S)比活力为研究对象 ,通过在离体和活体条件下比较其对甲磺隆的敏感性水平 ,探讨了水稻不同品种或组合的耐药性差异机制。结果表明 ,离体条件下不同水稻品种或组合 ALS对甲磺隆均较敏感 ,当甲磺隆浓度为 10 0μg/ L时 ,对 ALS比活力抑制率达 6 0 %以上 ,且活力百分比与甲磺隆浓度对数成直线负相关关系 ,相关程度显著或极显著 ;活体条件下 AL S活力均受到甲磺隆不同程度的抑制 ,但同一品种 AL S活力不随甲磺隆浓度的变化而呈现规律性变化。在甲磺隆浓度相同时 ,活体条件下所有供试水稻品种 AL S活力均显著高于离体条件下的 AL S活力 ,影响程度与植株耐药性差异基本一致 ,说明甲磺隆在水稻体内存在较强代谢失活作用 。

In order to study the mechanism of different tolerance of various rice species or combinations against metsulfuron methyl, the trial was carried out by the comparison between sensitivities of ALS to metsulfuron methyl in vitro and in vivo . The results showed that the relationship between percentages of ALS specific activities and logarithms of metsulfuron methyl concentrations in vitro was significantly negative linear correlation; ALS specific activities were inhibitted by metsulfuron methyl in vivo , but not changed regularly according to the increasing of the concentration of metsulfuron methyl. At the same metsulfuron methyl concentrations, ALS specific activities in vivo were obviously higher than that of in vitro , the difference was well correspondent with the tolerance of rice plant. Therefore, it was induced that metsulfuron methyl was strongly metabolized in rice and the difference of metabolic deactivation of metsulfuron methyl was the base for mechanism of various rice species or combinations against metsulfuron methyl.