河南省麦田荠菜对苯磺隆的抗性及其交互抗性

为明确河南省荠菜Capsella bursa-pastoris种群对苯磺隆的抗性水平及其可能存在的抗性机理,应用整株法测定了采自驻马店及南阳等6个荠菜发生严重市的10个荠菜种群对苯磺隆的抗性,扩增和比对了荠菜苯磺隆抗性种群及敏感种群之间靶标酶乙酰乳酸合成酶基因ALS的差异,并使用单剂量法测定了以上种群对双氟磺草胺、啶磺草胺及氟唑磺隆等ALS抑制剂类除草剂的交互抗性。结果表明,驻马店市的汝南县冯湾村(ZMD-1)及平舆县五里路村(ZMD-3)荠菜种群对苯磺隆的抗性倍数分别为3.1和2.5,表现出低水平抗性;驻马店市汝南县赖楼村(ZMD-2)和周口市川汇区文庄村(ZK-1)荠菜种群对苯磺隆的抗性倍数分别为21.7和57.8,表现出高水平抗性;南阳市唐河县上屯村(NY-2)荠菜种群对苯磺隆的抗性倍数为116.5,表现出极高水平抗性,其它种群对苯磺隆仍然较敏感。NY-2、ZMD-2和ZK-1种群的ALS基因第197位氨基酸由脯氨酸(CCT)分别突变为丝氨酸(TCT)、丙氨酸(GCT)和亮氨酸(CTT),其它种群中均未发现有突变产生;这3个种群在氟唑磺隆推荐剂量处理下,死亡率仅为18.9%、23.3%和11.1%,说明已对氟唑磺隆产生了较高水平的交互抗性,其中NY-2种群对双氟磺草胺和啶磺草胺产生了低水平交互抗性,推荐剂量下死亡率分别为82.2%和83.1%。表明ALS基因突变很可能是导致荠菜种群对苯磺隆等ALS抑制剂类除草剂产生抗性的重要原因。

Resistance to tribenuron-methyl and cross resistance in shepherd's purse Capsella bursa-pastoris from wheat fields in Henan Province

In order to examine the resistance level and the potential resistance mechanism to tribenuronmethyl in shepherd''s purse, Capsella bursa-pastoris, whole-plant dose-response experiments were conducted with ten populations collected from the wheat fields in Zhumadian, Nanyang and other places of Henan Province. ALS gene gene fragments were amplified, sequenced, and compared between the susceptible and resistant populations, and the whole-plant dose-response experiment was conducted to evaluate the cross resistance of shepherd''s purse populations to florasulam, pyroxsulam and flucarbazone-Na with single dose. The results showed that the populations collected from Fengwan Village, Runan County of Zhumadian City (ZMD-1) and Wulilu Village, Pingyu County of Zhumadian City (ZMD-3) displayed low-level resistance to tribenuron-methyl with a resistance index of 3.1 and 2.5, respectively; the populations collected from Lailou Village, Runan County of Zhumadian City (ZMD-2) and Wenzhuang Village, Chuanhui County of Zhoukou City (ZK-1) displayed high-level resistance with a resistance index of 21.7 and 57.8, respectively; the populations collected from Shangtun Village, Tanghe County of Nanyang City (NY-2) displayed very high resistance with a resistance index of 116.5; the other populations were still susceptible to tribenuron-methyl. Sequencing results showed that the mutation of proline (CCT) to threonine (TCT), alanine (GCT) and leucine (CTT) existed in ALS gene gene of NY-2, ZMD-2 and ZK-1 populations, and no mutations in other populations. The tribenuron-methyl-resistant populations also had high cross-resistance to flucarbazone-Na with a death rate of 18.9%, 23.3% and 11.1%, respectively; NY-2 population showed low-level cross-resistance to florasulam and pyroxsulam with a death rate of 82.2% and 83.1%, respectively, at recommended doses. The ALS gene gene mutations were very likely one of the key reasons resulting in tribenuron-methyl resistance of C. bursa-pastoris populations.