我国长江中下游稻区稗草对二氯喹啉酸的抗药性研究

Resistance of Echinochloa crusgalli(L.) Beauv.to Quinclorac in the Rice Growing region of the Middle and Lower Reaches of Yangtze River in China

2008至2011年,采集了我国长江中下游稻区的42个稗草[Echinochloa crusgalli(L.)Beauv.]生物型,采用盆栽法测定了其对二氯喹啉酸的抗药性。结果表明,湖南省益阳县(R1)和望城县(R2)的稗草生物型的抗性水平最高,分别达到21.84倍和32.31倍;浙江、江苏以及湖南省其他地区稗草生物型的抗性指数均在1.12～7.32倍,抗性较弱。经二氯喹啉酸处理后1d,上述两个抗性生物型稗草(R1、R2)的1-氨基环丙烷-1-羧酸合成酶(ACS)活性明显下降,为对照的49%和56%;2d后小幅回升,并维持在对照之下,然后继续下降,处理4d后下降至对照的34%和35%。经二氯喹啉酸处理后,R1和R2的β-氰丙氨酸合成酶(β-CAS)活性上升;处理5d后达到最高值,分别为对照的1.80倍和2.05倍。

The resistance of Echinochloa crusgalli（L.） Beauv.to quinclorac was determined by using pot planting method with 42 biotypes collected from the rice growing regions in the middle and lower reaches of the Yangtze River in China from 2008 to 2011.The results showed that higher resistance levels were observed in two biotypes of E.crusgalli from Yiyang County（R1） and Wangcheng County（R2）,Hunan Province with the resistance indexes（RI） of 21.84-and 32.31-fold,respectively.Other biotypes of E.crusgalli.from Hunan,Jiangsu and Zhejiang Province have developed lower level resistance（1.12-7.32-fold）.The 1-aminocyclopropane-1-carboxylate synthase（ACS） activity in the two resistance biotypes of E.crusgalli（R1 and R2） declined significantly one day after quinclorac treatment,with the RIs of 0.49-and 0.56-fold compared with the contemporary contro1.Then the activity increased slightly two days after treatment and remained to be lower than the control;however the activity decreased slowly to 0.34-and 0.35-fold relative to the control at four days after treatment The β-cyanoalanine（β-CAS） activity in R1 and R2 of E.crusgalli increased significantly after treated with quinclorac;the maximum were observed five days after treatment,being 1.80-and 2.05-fold,as high as the control,respectively.