河南省多花黑麦草对ACCase和ALS抑制剂的抗性及其靶标基因突变分析

为明确河南省部分地区的多花黑麦草Lolium multiflorum种群对乙酰辅酶A羧化酶（acetylCoA carboxylase,ACCase）和乙酰乳酸合成酶（acetolactate synthase,ALS）抑制剂类除草剂的抗性水平和抗性机理,采用整株生物测定法测定采自新乡市和驻马店市的多花黑麦草种群对ACCase抑制剂类除草剂精噁唑禾草灵、炔草酯、唑啉草酯和ALS抑制剂类除草剂甲基二磺隆、氟唑磺隆、啶磺草胺的抗性水平,并对多花黑麦草ACCase和ALS靶标酶编码基因进行克隆及氨基酸序列比对,分析其靶标抗性机理。结果显示,与多花黑麦草敏感种群HNXX01相比,HNZMD04和HNXX05种群对6种除草剂均产生了抗性,HNZMD04种群对精噁唑禾草灵和啶磺草胺的相对抗性倍数分别为44.65和40.31,对炔草酯和氟唑磺隆的相对抗性倍数分别为11.91和11.93;HNXX05种群对精噁唑禾草灵和氟唑磺隆的相对抗性倍数分别为27.70和25.67。HNZMD04和HNXX05抗性种群的ACCase基因均发生了D2078G突变,2个种群的突变率分别为55%和70%;HNZMD04...     

直播稻田牛筋草对乙酰辅酶A羧化酶类除草剂抗性水平及其分子机制

为明确直播稻田牛筋草对乙酰辅酶A羧化酶 (ACCase) 类除草剂的抗药性水平及其抗性产生的分子机制，采用整株生物测定法测定了牛筋草对6种ACCase类除草剂的抗性水平，并分别对抗性种群和敏感种群的ACCase基因部分片段进行了扩增和测序。结果表明:疑似抗性种群SJ-1对唑酰草胺、氰氟草酯、精唑禾草灵、高效氟吡甲禾灵和烯禾啶产生了高水平抗性，其抗性倍数分别为56.6、62.5、128、52.0和16.3；对烯草酮产生了低水平抗性，相对抗性倍数为4.86。将抗性种群和敏感种群的ACCase基因片段序列进行比对分析发现，SJ-1种群ACCase基因2078位氨基酸由天冬氨酸 (GAT) 突变为甘氨酸 (GGT)，该位点氨基酸突变可能是其对ACCase类除草剂产生抗药性的主要原因之一。     

抗精噁唑禾草灵的日本看麦娘ACCase基因突变

为明确日本看麦娘抗性种群对精噁唑禾草灵的抗性水平及抗性产生的分子机制,采用整株水平测定法测定了日本看麦娘对精噁唑禾草灵的抗性水平,扩增和比对了日本看麦娘抗性和敏感种群间乙酰辅酶A羧化酶(acetyl-Co A carboxylase,ACCase)基因的差异。结果显示,与敏感种群AH-7相比,抗性种群AH-25对精噁唑禾草灵的抗性倍数为33.82;AH-25种群ACCase基因CT区域2 078位氨基酸发生了突变,由天冬氨酸GAT突变为甘氨酸GGT;AH-25种群对炔草酯、烯草酮和烯禾啶产生了高水平的抗性,抗性倍数分别为35.66、38.64和29.14,对高效氟吡甲禾灵产生了低水平的抗性,抗性倍数为3.04,对精喹禾灵和唑啉草酯较敏感。表明ACCase基因2 078位氨基酸的突变可能是导致精噁唑禾草灵产生高水平抗性的重要原因。     

抗精噁唑禾草灵和甲基二磺隆看麦娘ACCase和ALS基因突变

为明确看麦娘Alopecurus aequalis抗性种群YL的靶标抗性机制,采用基因克隆法对看麦娘抗性和敏感种群间乙酰辅酶A羧化酶(ACCase)和乙酰乳酸合成酶(ALS)基因序列进行扩增、克隆和测序,比对二者ACCase和ALS基因序列的差异,探寻其产生抗药性突变的基因位点,同时测定该突变型抗性种群YL对不同ACCase和ALS抑制剂类除草剂的交互抗性。结果显示,与看麦娘敏感种群TL相比,抗性种群YL的ACCase基因CT区域第2 041位氨基酸由异亮氨酸(ATT)突变为天冬酰胺酸(AAT),ALS基因Domain A区域第197位氨基酸由脯氨酸(CCC)突变为精氨酸(CGC)。看麦娘抗性种群YL对ACCase抑制剂炔草酯产生了高水平抗性,抗性倍数为43.96,对高效氟吡甲禾灵和精喹禾灵产生了中等水平抗性,抗性倍数分别为18.33和15.87,对唑啉草酯、烯草酮和烯禾啶较敏感;对ALS抑制剂氟唑磺隆产生了低水平抗性,抗性倍数为8.39,对啶磺草胺和咪唑乙烟酸较敏感。表明ACCase基因第2 041位和ALS基因第197位氨基酸突变是导致看麦娘抗性种群YL对精噁唑禾草灵和甲基二磺隆同时产生抗性的重要原因之一。     

安徽省部分稻茬麦田看麦娘种群对常用ACCase类抑制剂的抗性现状及茎叶处理混用配方筛选

为明确看麦娘对乙酰辅酶A羧化酶(ACCase)抑制剂类除草剂的抗性现状，在安徽省看麦娘发生严重的稻茬麦田共采集30个种群，采用整株生物测定法分别测定了其对精噁唑禾草灵、炔草酯和唑啉草酯3种ACCase类除草剂的抗性水平。另选择三甲苯草酮、啶磺草胺等7种茎叶处理剂针对发现的高抗种群AHCZ-2进行了生物活性测定，同时将5种药剂与异丙隆混用开展了田间药效评价。结果显示：供试30个田间看麦娘种群中，26个种群对精噁唑禾草灵表现为高水平抗性，占供试种群总数的86.67%,GR50值(有效成分，下同)在230.93～1755.54 g/hm²之间，抗性指数(RI)达12.58～95.66;21个种群对炔草酯表现为高水平抗性，占种群总数的70.00%,GR50值在147.18～1213.44 g/hm²之间，RI达11.93～98.36;19个种群对唑啉草酯表现为高水平抗性，占种群总数的63.33%,GR₅₀值在107.63～614.18 g/hm²之间，RI达12.21～69.69；此外，采自相同地区的看麦娘...     

八种除草剂对小麦田三种抗精噁唑禾草灵杂草的生物活性

为筛选能有效防除抗精噁唑禾草灵杂草的除草剂,采用温室盆栽法测定菵草(敏感S_w、抗性R_w)、日本看麦娘(敏感S_r、抗性R_r)、耿氏硬草(敏感S_y、抗性R_y)对精噁唑禾草灵的抗性水平,并研究了8种除草剂对这3种抗性杂草的生物活性。结果显示,3种杂草抗性种群对精噁唑禾草灵的抗性指数均大于33.7,已达高抗水平。3种杂草抗性种群均对同类乙酰辅酶A羧化酶类抑制剂唑啉草酯和炔草酯产生了11.6~56.5倍不等的高水平抗性。对部分乙酰乳酸合成酶类抑制剂产生了2.0~4.8倍的低水平抗性,氟唑磺隆对3种杂草抗性种群防效较差,GR_(90)为67.31~114.39g(a.i.)/hm~2;啶磺草胺仅对Rr种群防效较好,GR_(90)为4.67 g(a.i.)/hm~2;甲基二磺隆对3种杂草抗性种群防效均较好,但对Rr种群存在抗性风险,已出现2.0倍低水平抗性;磺酰磺隆对Ry和Rr种群防效较好;丙苯磺隆对Rr种群防效好。细胞分裂抑制剂氟噻草胺对3种杂草抗性种群防效均最好,在田间推荐剂量120 g(a.i.)/hm~2下可达90%以上的防效。     

小麦田禾本科杂草适用除草剂及其使用技术

目前江苏省小麦生产上用于防除禾本科杂草的除草剂品种主要有7种:异丙隆、精(噁)唑禾草灵、甲基二磺隆、炔草酯、唑啉草酯、氟唑磺隆、啶草胺.本文介绍了这7种除草剂的除草特性和使用方法.     

上海市水稻田千金子对3种乙酰辅酶A羧化酶抑制剂的抗性现状及酶突变机制

为明确上海市水稻田千金子对乙酰辅酶A羧化酶 (ACCase) 抑制剂类除草剂的抗性发生情况及可能存在的抗性机制,在上海市千金子发生严重地区的水稻田共采集51个种群,采用单剂量抗性甄别法测定了不同千金子种群对3种ACCase抑制剂类除草剂的抗性水平,扩增和比对了靶标酶ACCase基因部分片段的差异。结果显示:在氰氟草酯105 g/hm2有效成分剂量选择压下,8个千金子种群标记为抗性种群,6个种群为发展中抗性种群;在噁唑酰草胺 120 g/hm2有效成分剂量选择压下,4个千金子种群标记为抗性种群,5个种群为发展中抗性种群;在精噁唑禾草灵62.1 g/hm2有效成分剂量选择压下,6个千金子种群标记为抗性种群,2个种群为发展中抗性种群。对15个抗性千金子种群靶标酶基因片段的测序发现,9个种群共发生了4种ACCase基因突变类型,分别为ACCase基因 1999 位点色氨酸 (TGG) 突变为丝氨酸 (TCG)、1999位点色氨酸 (TGG) 突变为半胱氨酸 (TGT)、2027位点色氨酸 (TGG) 突变为丝氨酸 (TCG) 以及2027位点色氨酸 (TGG) 突变为半胱氨酸 (TGT/TGC)。其中,5个抗性千金子种群ACCase 基因突变频率均大于60%。研究表明,ACCase抑制剂类除草剂抗性千金子在上海市部分地区发生已较为严重,ACCase 基因突变是导致不同千金子种群对该类除草剂产生抗性的重要原因之一。     

菵草对3种ACCase抑制剂抗性的琼脂快速检测方法建立

以菵草的1个敏感种群和2个抗药性种群为试材,在用整株测定法明确其对精唑禾草灵、高效氟吡甲禾灵、炔草酯3种ACCase抑制剂抗性水平的基础上,采用琼脂法,以新根率为指标筛选出3种药剂对抗性菵草的检测浓度。结果表明,整株测定法和琼脂法具有很好的相关性,通过琼脂法能够检测菵草对3种ACCase抑制剂的抗性,精唑禾草灵检测浓度为0.4μmol/L,高效氟吡甲禾灵检测浓度为0.2μmol/L,炔草酯检测浓度为0.4μmol/L,3种除草剂的最快检测时间为4 d。     

小麦田大穗看麦娘对精噁唑禾草灵的抗性

为明确小麦田大穗看麦娘对精噁唑禾草灵的抗性水平及产生抗性的机理,采用整株法测定了河南省小麦田大穗看麦娘种群对精噁唑禾草灵的抗性水平,以及细胞色素P450s抑制剂胡椒基丁醚(PBO)对精噁唑禾草灵的增效作用,并通过基因测序技术研究了其靶标ACCase基因的突变位点。结果显示:与敏感种群HN-06相比,抗性种群HN-05对精噁唑禾草灵的抗性倍数为52.2,其ACCase基因存在Ile-2041-Asn和Gly-2096-Ala位点突变;喷施PBO后,精噁唑禾草灵对大穗看麦娘的GR50值(有效成分)为5.4 g/hm^2,表现出明显的增效作用,与未喷施PBO处理的差异倍数为161.3。研究表明,抗性种群HN-05对精噁唑禾草灵已产生高水平抗性,该抗性的产生可能是由于其靶标基因突变和P450s介导的代谢增强同时导致的,即表现出了靶标抗性和非靶标抗性共存的现象。     

An aspartate to glycine change in the carboxyl transferase domain of acetyl CoA carboxylase and non‐target‐site mechanism(s) confer resistance to ACCase inhibitor herbicides in a Lolium multiflorum population

BACKGROUND: The increasing use of ACCase‐inhibiting herbicides has resulted in evolved resistance in key grass weeds infesting cereal cropping systems worldwide. Here, a thorough and systematic approach is proposed to elucidate the basis of resistance to three ACCase herbicides in a Lolium multiflorum Lam. (Italian rye grass) population from the United Kingdom (UK24). RESULTS: Resistance to sethoxydim and pinoxaden was always associated with a dominant D2078G (Alopecurus myosuroides Huds. equivalent) target‐site mutation in UK24. Conversely, whole‐plant herbicide assays on predetermined ACCase genotypes showed very high levels of resistance to diclofop‐methyl for all three wild DD2078 and mutant DG2078 and GG2078 ACCase genotypes from the mixed resistant population UK24. This indicates the presence of other diclofop‐methyl‐specific resistance mechanism(s) yet to be determined in this population. The D2078G mutation could be detected using an unambiguous DNA‐based dCAPS procedure that proved very transferable to A. myosuroides, Avena fatua L., Setaria viridis (L.) Beauv. and Phalaris minor Retz. CONCLUSION: This study provides further understanding of the molecular basis of resistance to ACCase inhibitor herbicides in a Lolium population and a widely applicable PCR‐based method for monitoring the D2078G target‐site resistance mutation in five major grass weed species. Copyright © 2010 Society of Chemical Industry     

Mechanisms of resistance to acetyl‐coenzyme A carboxylase‐inhibiting herbicides in a Hordeum leporinum population

A failure of acetyl‐coenzyme A carboxylase (ACCase)‐inhibiting herbicides to control a population of Hordeum leporinum Link (barleygrass) occurred following eight applications of these herbicides in both crops and pastures. This population was 7.6‐fold resistant to fluazifop‐P‐butyl compared with standard susceptible populations. The population was between 3.6‐ and 3.8‐fold resistant to other ACCase‐inhibiting herbicides, except butroxydim to which it was susceptible. ACCase extracted from resistant plants and assayed in the presence of herbicides in vitro was susceptible to fluazifop acid and other aryloxyphenoxypropanoate herbicides, but was 4‐fold less sensitive to sethoxydim compared with ACCase from susceptible plants. Resistant plants metabolised fluazifop acid about 1.3‐fold more rapidly compared with susceptible plants; however, sethoxydim was metabolised equally in both populations. Resistance to fluazifop‐P‐butyl and other aryloxyphenoxypropanoate herbicides may be the result of increased herbicide detoxification, whereas resistance to sethoxydim appears to be due to a modified target enzyme. Herbicide resistance in this population is unusual in that different mechanisms appear to confer resistance to the aryloxyphenoxypropanoate and cyclohexanedione herbicides. © 2000 Society of Chemical Industry     

广东省稻菜轮作区中牛筋草对十种除草剂的抗性水平及靶基因序列分析

为明确广东省稻菜轮作区中牛筋草对10种常用除草剂的抗性水平及抗性分子机制,采用整株生物测定法测定广东省稻菜轮作区内8个牛筋草种群P1～P8对草甘膦、草铵膦和乙酰辅酶A羧化酶(acetyl-CoA carboxylase,ACCase)抑制剂类等10种除草剂的抗性水平,并进一步分析P1和P8种群相关靶标酶基因5-烯醇丙酮酰莽草酸-3-磷酸合酶(5-enolpyruvyl-shikimate-3-phosphate synthase,EPSPS)、谷氨酰胺合成酶(glutamine synthetase,GS)和ACCase的部分功能区序列特征。结果显示,牛筋草P1～P8种群对草甘膦抗性指数为敏感种群的5.9倍～17.7倍,其中P8种群对草甘膦的抗性水平最高;8个种群对草铵膦也产生了不同程度的抗性,抗性指数为敏感种群的2.3倍～14.2倍,其中P1种群抗性最高。牛筋草P1和P8种群均对ACCase抑制剂类除草剂精喹禾灵、氰氟草酯和噁唑酰草胺产生了交互抗性;P1种群ACCase基因在第2 041位氨基酸处发生突变,该突变在牛筋草种群中首次发现;而P8种群ACCase基因则在第2 027位氨基...     

荠菜对乙酰乳酸合成酶抑制剂类除草剂的抗性水平及其分子机制

为明确荠菜种群对苯磺隆的抗性水平及其靶标抗性产生的分子机制,采用整株水平测定法测定了荠菜对苯磺隆及其他5种乙酰乳酸合成酶（ALS）抑制剂类除草剂的抗性水平,同时扩增和比对了荠菜抗性和敏感种群之间ALS基因的差异。结果显示:与敏感种群15-ZMD-1相比,抗性种群15-ZMD-5对苯磺隆产生了高水平抗性,抗性倍数为219.6;15-ZMD-5种群不同单株中共存在3种突变方式,分别为ALS基因197位点脯氨酸（CCT）突变为亮氨酸（CTT）、574位点色氨酸（TGG）突变为亮氨酸（TTG）以及单株同时发生上述197和574位点的氨基酸突变。15-ZMD-5抗苯磺隆种群对嘧草硫醚、啶磺草胺和氟唑磺隆均产生了高水平的交互抗性,抗性倍数分别为41.2、79.3和87.8;对双氟磺草胺和咪唑乙烟酸产生了低水平的交互抗性,抗性倍数分别为8.5和5.6。分析表明,荠菜抗性种群ALS基因发生的氨基酸突变可能是导致其对ALS抑制剂类除草剂产生抗性的重要原因之一。     

Molecular characterization and inheritance of resistance to ACCase-inhibiting herbicides in Lolium rigidum

The molecular basis and mode of inheritance of resistance to ACCase-inhibiting herbicides were investigated in a biotype of Lolium rigidum Gaud that has been discovered in Israel. Dose-response experiments at the whole-plant level have revealed that the resistant biotype was more resistant (6.3- to 40-fold) than the susceptible wild-type to ACCase-inhibiting herbicides. A 276-bp genomic DNA encoding the carboxyltransferase domain within the chloroplastic ACCase from resistant and susceptible biotypes were amplified by PCR and analyzed. Sequence comparison revealed that a single isoleucine-to-leucine substitution differentiated ACCases from susceptible and resistant biotypes (corresponds to residue 1769 of wheat ACCase, Acc No AF029895). A PCR amplification of specific alleles (PASA) method was developed to detect the allele composition leading to isoleucine-leucine mutation. ACCase extracted from homozygote resistant, heterozygote and homozygote susceptible plants showed IC50 values of 25.8, 5.6 and 0.6 microM, respectively, suggesting that alteration in the ACCase is governed by a co-dominant gene. The inheritance studies confirmed that the resistance of L rigidum to ACCase-inhibiting herbicides is governed by a single, nuclear and co-dominant gene.     

Cross-resistance patterns to ACCase-inhibiting herbicides conferred by mutant ACCase isoforms in Alopecurus myosuroides Huds. (black-grass), re-examined at the recommended herbicide field rate

BACKGROUND: Target‐site‐based resistance to acetyl‐CoA carboxylase (ACCase) inhibitors in Alopecurus myosuroides Huds. is essentially due to five substitutions (Isoleucine‐1781‐Leucine, Tryptophan‐2027‐Cysteine, Isoleucine‐2041‐Asparagine, Aspartate‐2078‐Glycine, Glycine‐2096‐Alanine). Recent studies suggested that cross‐resistance patterns associated with each mutation using a seed‐based bioassay may not accurately reflect field resistance. The authors aimed to connect the presence of mutant ACCase isoform(s) in A. myosuroides with resistance to five ACCase inhibitors (fenoxaprop, clodinafop, haloxyfop, cycloxydim, clethodim) sprayed at the recommended field rate. RESULTS: Results from spraying experiments and from seed‐based bioassays were consistent for all mutant isoforms except the most widespread, Leucine‐1781. In spraying experiments, Leucine‐1781 ACCase conferred resistance to clodinafop and haloxyfop. Some plants containing Leucine‐1781 or Alanine‐2096 ACCase, but not all, were also resistant to clethodim. CONCLUSION: Leucine‐1781, Cysteine‐2027, Asparagine‐2041 and Alanine‐2096 ACCases confer resistance to fenoxaprop, clodinafop and haloxyfop at field rates. Leucine‐1781 ACCase also confers resistance to cycloxydim at field rate. Glycine‐2078 ACCase confers resistance to all five herbicides at field rates. Only Glycine‐2078 ACCase confers clethodim resistance under optimal application conditions. It may be that Leucine‐1781 and Alanine‐2096 ACCases may also confer resistance to clethodim in the field if the conditions are not optimal for herbicide efficacy, or at reduced clethodim field rates. Copyright © 2008 Society of Chemical Industry