江苏省不同地区猪殃殃种群对常用除草剂的敏感性差异

采用整株生测法测定采自江苏省不同地区的20个猪殃殃种群对麦田常用除草剂苯磺隆、苄嘧磺隆、二甲四氯钠、氯氟吡氧乙酸、唑草酮的敏感性差异。结果表明,苯磺隆处理后,20个种群中有12个种群的ED50值超过推荐剂量,对苯磺隆产生明显的抗性;12个抗苯磺隆种群中有10个种群对苄嘧磺隆产生交互抗性,4个种群对二甲四氯钠产生多抗性,但对氯氟吡氧乙酸、唑草酮敏感;抗乙酰乳酸合酶(ALS)抑制剂类除草剂的猪殃殃种群比例呈现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,部分抗ALS种群对二甲四氯钠具有多抗性,但抗性种群均对氯氟吡氧乙酸、唑草酮敏感。     

几种除草剂防除小麦田间猪殃殃的效果研究

为寻找对小麦田间猪殃殃杂草防治的理想药剂品种,进行了16%双氟·氯氟吡等7种药剂品种田间药效试验.结果表明,3%双氟·唑草酮、36%唑草·苯磺隆对猪殃殃杂草防效好,见效快,施用应避开寒流天气;双氟·氟氯酯、双氟·氯氟吡及氯氟吡氧乙酸对猪殃殃杂草有较好的防效且使用安全;苯磺隆对猪殃殃杂草防效差,生产上不宜单用.     

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。     

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。     

QuEChERS-超高效液相色谱-串联质谱法测定双氟磺草胺和氯氟吡氧乙酸在小麦和土壤中的残留及消解动态

建立了同时测定小麦及其土壤中双氟磺草胺和氯氟吡氧乙酸残留的QuEChERS-超高效液相色谱-串联质谱方法,并采用该方法研究了低温冷藏条件下双氟磺草胺和氯氟吡氧乙酸在小麦上的储藏稳定性以及15%双氟磺草胺?氯氟吡氧乙酸悬乳剂在小麦和土壤中的最终残留及消解动态。结果表明:在添加水平为0.005~1 mg/kg范围内,双氟磺草胺和氯氟吡氧乙酸在小麦及土壤中的平均回收率在82%~108%之间,相对标准偏差在0.41%~11%之间 (n=5) ,均能满足农药残留分析的要求。在 –20℃下储藏365 d后,麦粒中双氟磺草胺和氯氟吡氧乙酸的残留量变化小于30%,符合植源性农产品中农药残留储藏稳定性试验准则要求,储藏稳定。双氟磺草胺在小麦植株和土壤中的消解半衰期分别为4.4~8.1 d和2.4~9.3 d;氯氟吡氧乙酸在小麦植株和土壤中的消解半衰期分别为7.9~10.6 d和11.8~24.8 d,即在相同的试验条件下双氟磺草胺在植株和土壤中消解速率快于氯氟吡氧乙酸的。采用推荐剂量有效成分180 g/hm2和推荐高剂量有效成分270 g/hm2的15%双氟磺草胺?氯氟吡氧乙酸悬乳剂于小麦田施药1次,在小麦收获期的麦粒中均未检出双氟磺草胺和氯氟吡氧乙酸残留。     

天津市小麦田荠菜对双氟磺草胺的抗性及其乙酰乳酸合成酶基因突变

为明确天津市小麦田荠菜种群对双氟磺草胺的抗性情况及可能的抗性机理,本研究在天津市静海区、武清区、宝坻区及蓟州区等荠菜发生严重地区的小麦田共采集到6个荠菜种群,采用整株水平测定法测定了6个荠菜种群对双氟磺草胺的抗性水平,并扩增、比对了其靶标乙酰乳酸合成酶 (ALS) 基因部分片段的差异。结果表明:6个荠菜种群对双氟磺草胺均产生了高抗性,抗性倍数在11.4~47.2之间。对抗性和敏感种群的ALS基因片段进行测定比对发现,6个荠菜种群ALS基因197位氨基酸均由脯氨酸 (CCT) 突变为丝氨酸 (TCT),该突变可能是导致荠菜种群对双氟磺草胺产生抗性的重要原因之一。     

宁夏地区稗草种群对五氟磺草胺的抗性机制研究

为了明确宁夏稻区稗草对五氟磺草胺抗性水平及抗性机制。采用整株生物测定法测定了宁夏地区6个稗的原变种Echinochloa crus-galli var.crus-galli种群对五氟磺草胺的抗性水平,并测定了每个种群的乙酰乳酸合酶基因(ALS)序列和ALS酶离体活性,以及P450抑制剂马拉硫磷对稗草种群抗性水平的影响。结果显示,与敏感种群相比,5个疑似抗性种群对五氟磺草胺表现出不同程度的抗性(10.18倍～32.71倍),其中抗性种群N14,N22,N27和N51的ALS 574位色氨酸突变为亮氨酸,N53的197位脯氨酸突变为亮氨酸,敏感种群N43没有发现突变位点,五氟磺草胺对抗性种群ALS酶的IC₅₀均明显高于敏感种群,马拉硫磷对五氟磺草胺有增效作用,可提高稗草种群对五氟磺草胺的敏感性。综上所述,稗草种群对五氟磺草胺产生抗性是由于靶标基因ALS突变,同时稗草种群对五氟磺草胺的抗性也可能与细胞色素P450介导的代谢增强有关。     

12%双氟磺草胺·唑草酮·氯氟吡氧乙酸悬浮剂对冬小麦田阔叶杂草的防除效果及安全性研究

为明确12%双氟磺草胺·唑草酮·氯氟吡氧乙酸悬浮剂在冬小麦田的应用前景,采用了田间小区试验的方法,研究其对冬小麦田主要阔叶杂草的控制作用和对小麦的安全性。结果表明:12%双氟·唑·氯氟吡氧乙酸悬浮剂对冬小麦田主要阔叶杂草猪殃殃、荠菜、播娘蒿、繁缕等阔叶杂草均有较好的防除效果,随用药量的增加防效逐渐提高,各处理药后30 d株数防效和鲜质量防效均在95%以上,优于苯磺隆常规剂量处理的防效,对小麦安全性良好,提高了小麦的产量。     

几种除草剂防除冬小麦田阔叶杂草试验研究

试验表明:5.8%双氟·唑嘧磺悬浮剂(麦喜)10mL/667m2、20%氯氟吡氧乙酸乳油(使它隆)20mL/667m2 10%苯磺隆可湿性粉剂10g/667m2、20%氯氟吡氧乙酸乳油(使它隆)20mL/667m2 75%苯磺隆干悬浮剂(巨星)1g/667m2对小麦田阔叶杂草(猪殃殃、播娘蒿、荠菜)药后45d防效均在83.4%～89.8%之间,可以有效控制麦田阔叶杂草。几种除草剂对荠菜、播娘蒿的防效相当,对猪殃殃的防效,以5.8%双氟·唑嘧磺悬浮剂(麦喜)处理的最好,以75%苯磺隆干悬浮剂(巨星)处理的最差。     

河南省猪殃殃对苯磺隆的抗性检测

为了明确河南省猪殃殃对苯磺隆的抗性水平及分布现状,通过温室整株生物测定法,测定了河南省境内36个猪殃殃种群对苯磺隆的敏感性。结果表明,河南省大部分猪殃殃种群已经对苯磺隆产生了不同程度的抗性,所测样品中,高抗种群3个,中抗种群9个,低抗种群13个,共25个,占总采样数的69.44%;敏感种群11个,占30.56%。说明苯磺隆在河南多地存在高抗性风险,同类乙酰乳酸合成酶抑制剂类除草剂需科学施用。     

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。     

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...     

猪殃殃对AHAS抑制剂靶标抗性的快速分子检测

为建立猪殃殃靶标抗性快速检测方法,并明确小麦田猪殃殃Galium aparine var.tenerum对AHAS抑制剂靶标的突变类型及分布,从河南、陕西、安徽、江苏和山东5省不同田块采集疑似对AHAS抑制剂产生抗性的猪殃殃植株,采用特异性引物PCR扩增靶标酶AHAS基因保守区片段,并以直接测序法检测采集样品,通过与拟南芥AHAS基因序列比对分析后明确其突变位点。结果显示,在5省25个农田的样品中共有19个农田检测到AHAS突变,分布在河南、安徽和江苏3省;在检测样品中发现突变发生在2个位点,共有3种突变类型,分别是197位脯氨酸(CCC)突变为丙氨酸(GCC)或丝氨酸(TCC),或者是574位色氨酸(TGG)突变为亮氨酸(TTG),检测结果与田间药效反应基本一致。这种用特异性引物扩增目的片段测序的方法,由于其可以在生长当季进行检测,适用于田间靶标突变抗性猪殃殃的快速检测与监测。     

Mutations of the ALS gene endowing resistance to ALS-inhibiting herbicides in Lolium rigidum populations

BACKGROUND: In the important grass weed Lolium rigidum (Gaud.), resistance to ALS‐inhibiting herbicides has evolved widely in Australia. The authors have previously characterised the biochemical basis of ALS herbicide resistance in a number of L. rigidum biotypes and established that resistance can be due to a resistant ALS and/or enhanced herbicide metabolism. The purpose of this study was to identify specific resistance‐endowing ALS gene mutation(s) in four resistant populations and to develop PCR‐based molecular markers. RESULTS: Six resistance‐conferring ALS mutations were identified: Pro‐197‐Ala, Pro‐197‐Arg, Pro‐197‐Gln, Pro‐197‐Leu, Pro‐197‐Ser and Trp‐574‐Leu. All six mutations were found in one population (WLR1). Each Pro‐197 mutation conferred resistance to the sulfonylurea (SU) herbicide sulfometuron, whereas the Trp‐574‐Leu mutation conferred resistance to both sulfometuron and the imidazolinone (IMS) herbicide imazapyr. A derived cleaved amplified polymorphic sequences (dCAPS) marker was developed for detecting resistance mutations at Pro‐197. Furthermore, cleaved amplified polymorphic sequences (CAPS) markers were developed for detecting each of the six mutant resistant alleles. Using these markers, the authors revealed diverse ALS‐resistant alleles and genotypes in these populations and related them directly to phenotypic resistance to ALS‐inhibiting herbicides. CONCLUSION: This study established the existence of a diversity of ALS gene mutations endowing resistance in L. rigidum populations: 1–6 different mutations were found within single populations. At field herbicide rates, resistance profiles were determined more by the specific mutation than by whether plants were homo‐ or heterozygous for the mutation. Copyright © 2008 Society of Chemical Industry     

Cross-resistance of horseweed (Conyza canadensis) populations with three different ALS mutations

BACKGROUND: Horseweed is a weed commonly found in agronomic crops, waste areas and roadsides. Resistance to ALS‐inhibiting herbicides in horseweed was first reported in 1993 in a population from Israel. Resistance to ALS‐inhibiting herbicides in horseweed is now widespread, but, as of now, the resistance mechanism has not been reported. RESULTS: Two of three populations evaluated (P116 and P13) were found to be uniform for resistance (>98% of individuals survived 8.8 g AI ha^?1 of cloransulam), whereas a third population, P525, contained about 85% resistant individuals. Cross‐resistance to cloransulam, chlorimuron, imazethapyr and bispyribac was observed in the P116 population. P525 and P13 were both sensitive to imazethapyr but resistant to chlorimuron, imazethapyr and bispyribac. Enzyme activity assays indicated that resistance in P13 was due to an altered target site. Southern blot analysis indicated that the ALS target site is encoded by a single copy gene. Overlapping ALS gene regions were amplified and sequenced from each population. Amino acid substitutions of Ser for Pro at position 197 (P197S) was detected from P13, Ala for Pro (P197A) was identified from P525 and substitution of Glu for Asp (D376E) at position 376 was found in P116. Molecular markers were developed to differentiate between wild‐type and resistant codons at positions 197 and 376 of horseweed ALS. CONCLUSION: Resistance to ALS‐inhibiting herbicides in horseweed is conferred by target‐site mutations that have also been identified in other weed species. Identification of the mutations within horseweed ALS gene sequence enables molecular assays for rapid detection and resistance diagnosis. Copyright © 2011 Society of Chemical Industry     

Corn poppy (Papaver rhoeas) cross-resistance to ALS-inhibiting herbicides

BACKGROUND: Papaver rhoeas (L.) has evolved resistance to tribenuron in winter wheat fields in northern Greece owing to multiple Pro₁₉₇ substitutions. Therefore, the cross‐resistance pattern to other sulfonylurea and non‐sulfonylurea ALS‐inhibiting herbicides of the tribenuron resistant (R) and susceptible (S) corn poppy populations was studied by using whole‐plant trials and in vitro ALS catalytic activity assays. RESULTS: The whole‐plant trials revealed that tribenuron R populations were also cross‐resistant to sulfonylureas mesosulfuron + iodosulfuron, chlorsulfuron and triasulfuron. The whole‐plant resistance factors (RFs) calculated for pyrithiobac, imazamox and florasulam ranged from 12.4 to > 88, from 1.5 to 28.3 and from 5.6 to 25.4, respectively, and were lower than the respective tribenuron RF values (137 to > 2400). The ALS activity assay showed higher resistance of the ALS enzyme to sulfonylurea herbicides (tribenuron > chlorsulfuron) and lower resistance to non‐sulfonylurea ALS‐inhibiting herbicides (pyrithiobac > florasulam ≈ imazamox). CONCLUSION: These findings indicate that Pro₁₉₇ substitution by Ala, Ser, Arg or Thr in corn poppy results in a less sensitive ALS enzyme to sulfonylurea herbicides than to other ALS‐inhibiting herbicides. The continued use of sulfonylurea herbicides led to cross‐resistance to all ALS‐inhibiting herbicides, making their use impossible in corn poppy resistance management programmes. Copyright © 2011 Society of Chemical Industry     

An assessment of the possible reasons for differential tolerance to fluroxypyr in selected populations of Galium aparine

In an investigation of the possible reasons for tolerance lo fluroxypyr by Galium aparine L. (cleavers), a wide range of variation in total herbicide retention was exhibited by nine diverse populations from throughout Europe. Although these differences in fluroxypyr relention became negligible when considered on a unit area basis, a two-fold difference was maintained per unit dry matter. There was no difference in fluroxypyr uptake between a fluroxypyr-tolerant and a fluroxypyr-susceptible population, and differences in translocation between the two populations did not seem to explain the differential tolerance. It is suggested that differential metabolic detoxification may be the main reason for the variation in response to fluroxypyr by populations of G. aparine.     

稻稗HJHL-715种群对五氟磺草胺的抗药性水平及抗性机理分析

为明确东北稻区稻稗Echinochloa oryzoides HJHL-715种群对五氟磺草胺的抗性水平及抗性机制,采用整株生物测定法测定稻稗种群对五氟磺草胺的敏感性,明确抗性种群的交互抗性和多抗性情况,研究3种细胞色素P450抑制剂对其敏感性的影响;并应用分子生物学方法进行稻稗的乙酰乳酸合酶(acetolactate synthase,ALS)离体活性测定、ALS基因序列分析及其表达量测定。结果表明:在东北稻区,五氟磺草胺对稻稗HJHL-715种群鲜重的抑制中剂量GR50为62.53 g/hm^2;稻稗HJHL-715的ALS基因序列中未发现氨基酸突变,其ALS离体活性与敏感种群的ALS离体活性无显著性差异,ALS基因表达量显著低于敏感种群。1-氨基苯并三唑(1-aminobenzotriazole,ABT)、胡椒基丁醚(piperomyl butoxide,PBO)、马拉硫磷3种P450抑制剂显著提高了稻稗HJHL-715种群对五氟磺草胺的敏感性,使其对五氟磺草胺的GR50由原来的62.53 g/hm^2分别下降到5.78、5.02、3.53 g/hm^2。表明东北稻区已经出现了对五氟磺草胺具有高水平抗性的稻稗种群,稻稗HJHL-715种群对五氟磺草胺的抗性很可能是由细胞色素P450介导的代谢增强所致。