野慈姑对吡嘧磺隆抗性的分子机理

Molecular Resistance Mechanism of Sagittaria trifolia L.to Pyrazosulfuron- methyl

野慈姑是我国稻田危害最严重的杂草之一。以黑龙江稻田采集的野慈姑(Sagittaria trifolia Linn.)为研究对象,通过室内生物测定和分子克隆技术,对野慈姑的吡嘧磺隆抗性水平进行检测,并从靶标位点突变的角度解释抗性产生原因。结果表明,采自哈尔滨稻田的2个野慈姑种群N03及N06均为高抗种群,抗性达到4倍剂量以上。经比对2个抗性种群的靶标酶ALS基因发现,Pro197的脯氨酸分别被亮氨酸、丝氨酸取代,该位点的突变可能是野慈姑种群对磺酰脲类除草剂产生抗药性的主要原因。

Sagittaria trifolia L. is one of the most serious weeds in paddy fields in China. In this study,two S. trifolia populations collected from Heilongjiang Province were found highly resistant（ resistance indexes above 4. 0） to pyrazosulfuron- methyl in dose- response curves. The resistance mechanism was elucidated through amplifycation and cloning sections of the ALS gene. Different mutations were found in Pro197 in the two resistant populations. In one of the populations（ N03）,CCC was changed to CTC / CCC at 197,leading to the substitution of Pro by Leu / Pro. Population N06 possessed a TCC to CCC mutation,resulting in a Ser- 197- Pro substitution. These mutations may be responsible for the resistance mechanism.