反枝苋对硝磺草酮的敏感性水平及非靶标抗药性初探

Preliminary study on sensitivity level and non-target resistance of Amaranthus retroflexus to mesotrione

[目的]测定辽宁省不同地区的反枝苋种群对硝磺草酮的敏感性水平及交互抗药性,并对其非靶标抗性机制进行初步探索。[方法]采用单剂量甄别法以及整株生物测定法测定反枝苋种群对硝磺草酮的敏感性水平,选择环磺酮和苯唑草酮验证其交互抗药性。同时,选择马拉硫磷作为P450s抑制剂,探究抗、敏种群之间P450s活性差异。[结果]30个种群中共有敏感种群4个,低抗种群7个,中抗种群9个,高抗种群10个,抗性指数在2~38.17之间。抗性种群LN6、LN20、LN24对环磺酮和苯唑草酮均有抗药性产生,马拉硫磷对抗性种群LN9、LN20、LN25均有增效作用,其中LN25增效作用最为明显,GR50值由225.91 g a.i./hm^(2)降为141.32 g a.i./hm^(2);LN9的GR50值由186.94 g a.i./hm^(2)降为126.82 g a.i./hm^(2);LN20的GR50值由94.52 g a.i./hm^(2)降为63.52 g a.i./hm^(2)。[结论]辽宁省内反枝苋对硝磺草酮产生了不同程度的抗性,并对环磺酮和苯唑草酮产生交互抗性。P450s活性上升是介导反枝苋对硝磺草酮产生抗药的主要原因。

[Aims]To determine the sensitivity level and cross-resistance of Amaranthus retroflexus population to mesotrione in different areas of Liaoning Province,and to explore the non-target resistance mechanism.[Methods]Single dose screening and whole plant bioassay were used to determine the sensitivity of A.retroflexis populations to mesotrione,and tembotrione and topramezone were selected to verify the cross-resistance.At the same time,malathion was selected as the P450s inhibitor to explore the difference of P450s activity between resistant populations and sensitive populations.[Results]Among the 30 populations,4 were sensitive,while 7 were low resistant,9 were medium resistant and 10 were high resistant,with the resistance index ranged from 2 to 38.17.LN6,LN20 and LN24 showed resistance to tembotrione and topramezone,while LN9,LN20 and LN25 showed synergic effect against malathion,and LN25 showed the most obvious synergic effect,with GR50 decreased from 225.91 to 141.32 g a.i./ha.The GR50 value of LN9 decreased from 186.94 to 126.82 g a.i./ha.The GR_(50) value of LN20 decreased from 94.52 to 63.52 g a.i./ha.[Conclusions]A.retroflexus in Liaoning province developed different degree of resistance to mesotrione,and cross-resistance to tembotrione and topramezone.The increase of P450s activity is the main reason for the resistance of A.retroflexus to mesotrione.