江苏省麦田猪殃殃对苯磺隆的抗性水平及靶标抗性机理研究

为了明确江苏省麦田猪殃殃对主导除草剂苯磺隆的敏感性差异及其抗性机制,采用整株生测法测定了采自江苏省小麦田的28个猪殃殃(Galium aparine L.)种群对苯磺隆、苄嘧磺隆、氯氟吡氧乙酸、2甲4氯钠、唑草酮的敏感性,分析了代表性种群乙酰乳酸合酶(acetolactate synthase, ALS)的离体活性及其基因位点突变状况。结果表明,28个种群中,23个种群对苯磺隆有2.18~17.10倍的相对抗性,18个种群对苄嘧磺隆产生了交互抗性,所有种群对氯氟吡氧乙酸、2甲4氯钠、唑草酮均敏感。LHQ-2和JYS-1种群的相对抗性倍数高于14,ALS酶离体活性达到敏感种群DHX-2的250倍以上,其第197位由脯氨酸突变为苏氨酸;WJQ-2种群的相对抗性倍数为10.39,ALS酶离体活性是敏感种群DHX-2的41.45倍,其第376位由天冬氨酸突变为甘氨酸;RGS-1种群的相对抗性倍数为8.82,ALS酶离体活性是敏感种群DHX-2的15.27倍,其第574位由色氨酸突变为亮氨酸。抗苯磺隆的猪殃殃种群比例呈现由苏南到苏北逐渐增加的趋势,苯磺隆和苄嘧磺隆间存在交互抗性,靶标酶ALS活性增强及其基因位点突变是抗性产生的主要原因。本研究结果为江苏省麦田猪殃殃的精准防控提供了理论依据和技术支撑。

Resistance of Galium aparine to Tribenuron-methyl and Its Resistance Mechanism in Wheat Fields in Jiangsu Province

In order to provide a theoretical basis for the sustainable management of Galium aparine L. in wheat fields in Jiangsu Province, the whole plant bioassay method was used to determine the sensitivity of 28 G. aparine L. populations collected from wheat fields in Jiangsu Province to tribenuron-methyl, bensulfuron-methyl, fluroxypr, MCPA-Na, and carfentrazone-ethyl. Besides this, the in vitro activity and gene mutation of acetyllactate synthase (ALS) of representative populations were analyzed. The results showed that among the 28 populations, 23 populations had 2.18~17.10 times relative resistance to tribenuron-methyl, 18 populations had cross resistance to bensulfuron-methyl, and all populations were sensitive to luroxypr, MCPA-Na, and carfentrazone-ethyl. The in vitro activity of ALS enzyme in LHQ-2 and JYS-1 populations with relative resistance index higher than 14 was more than 250 times higher than that in DHX-2, and the 197th position was mutated from proline to threonine. The in vitro activity of ALS enzyme in WJQ-2 population with relative resistance index of 10.39 was 41.45 times higher than that in DHX-2 population, and its 376th position was mutated from aspartic acid to glycine. The in vitro activity of ALS enzyme in RGS-1 population with relative resistance multiple of 8.82 was 15.27 times higher than that in DHX-2 population, and its 574th position was mutated from tryptophan to leucine. The proportion of G. aparine L. population resistant to tribenuron-methyl showed a trend of gradually increasing from southern Jiangsu to northern Jiangsu. There was cross resistance between tribenuron-methyl and bensulfuron-methyl. The strengthening of target enzyme ALS activity and ALS gene mutation were the main reasons for the enhanced resistance. All populations were sensitive to fluroxypr, MCPA-Na, and carfentrazone-ethyl. The results of this study provide theoretical basis and technical support for the sustainable management of G. aparine L. in wheat field in Jiangsu Province.