A molecular assay for the proactive detection of target site-based resistance to herbicides inhibiting acetolactate synthase in Alopecurus myosuroides

Acetolactate synthase (ALS) inhibitors are the most resistance‐prone herbicide group. Rapid resistance diagnosis is thus of importance for their optimal use. We formulate rules to use the derived cleaved amplified polymorphic sequence method to develop molecular tools detecting a change at a given codon, the nature of which is unknown. We applied them to Alopecurus myosuroides (black grass) to develop assays targeting ALS codons A122, P197, A205, W574 and S653 that are crucial for herbicide sensitivity. These assays detected W574L or P197T, or both substitutions, in most plants analysed from a field where ALS inhibitors failed after 3 years of use. Similar assays can easily be set up for any species. Given the rapidity of selection for resistance to ALS inhibitors, these assays should be very useful in proactive herbicide resistance diagnosis.     

看麦娘对甲基二磺隆靶标抗性的快速检测

甲基二磺隆是防除小麦田看麦娘Alopecurus aequalis等禾本科杂草的主要除草剂品种之一,但目前中国山东、江苏及安徽等地已有部分看麦娘种群对其产生了抗性。ALS基因197位点突变是看麦娘对甲基二磺隆产生抗性的重要机理,根据突变型和野生型看麦娘在197位点处碱基序列的不同,本研究设计出了一种衍生性酶切扩增多态性序列(dCAPS)分子标记方法,可用于197位点突变的快速检测。通过在引物D197F序列的3′ 端引入一个错配碱基,扩增所得不同种群看麦娘的ALS片段经限制性内切酶BamH I酶切后表现出多态性:野生敏感型分别产生了200和36 bp的2个条带;纯合突变型因无法被切开,只有236 bp的一个条带;而杂合突变型则同时产生了上述3个条带。该dCAPS检测结果准确、可靠,与经典的整株水平测定结果一致,并且可同时检测197位点上任一形式的突变。研究结果可为看麦娘等禾本科杂草对甲基二磺隆靶标抗性的快速检测提供理论依据。     

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     

Derived cleaved amplified polymorphic sequence, a simple method to detect a key point mutation conferring acetyl CoA carboxylase inhibitor herbicide resistance in grass weeds

Substitution of isoleucine by leucine at the equivalent of residue 1781 of acetyl CoA carboxylase (ACCase) in Alopecurus myosuroides (I1781L) has been shown to be a key point mutation conferring resistance to most aryloxypropionate and cyclohexanedione herbicides in Lolium spp., A. myosuroides, Avena fatua and Setaria viridis. This substitution results from changing an adenine residue to either thymine or cytosine at position 5341 in the ACCase coding sequence of A. myosuroides and at the homologous position in the other species. The I1781L mutation can be detected by allele‐specific amplification assays. These are, however, very dependent on the conservation of the nucleotide sequences flanking the causative single nucleotide polymorphism. Moreover, such assays cannot distinguish between homozygous and heterozygous individuals in a single polymerase chain reaction reaction. Here we present an alternative derived Cleaved Amplified Polymorphic Sequence (dCAPS) method to define I1781L status in the ACCase enzyme of four grass weeds. This dCAPS approach is simple, economical, highly transferable between species and can readily distinguish homozygous Leu/Leu 1781 and heterozygous Ile/Leu 1781 resistant individuals, providing the basis for accurate measures of the frequency of the dominant Leu allele in a given population.     

Real-time quantitative PCR assays for quantification of L1781 ACCase inhibitor resistance allele in leaf and seed pools of Lolium populations

The I1781L amino acid substitution in the target ACCase enzyme causes broad resistance to ACCase inhibitor herbicides in several monocotyledenous weeds of agronomic importance. This mutation results from a substitution of an adenine (A) residue by either a thymine (T) or cytosine (C) at position 5341 in Alopecurus myosuroides Huds and at an equivalent position in Lolium species, Avena fatua L. and Setaria viridis (L.) Beauv. Two different procedures, the PCR-based allele-specific assay (ASA) and the derived cleaved amplified polymorphic sequence (dCAPS) method, have previously been described for detecting this mutation. These methods are, however, only amenable to low sample throughput and are used in the analysis of single plants. Here, an alternative high-throughput ARMS/Scorpion real-time quantitative PCR (Q-PCR) method for measuring levels of the I1781L mutation in pools of leaf and seed samples of Lolium populations is presented. The limit of detection for C and T mutant alleles in a background of wild-type A is 0.02 and 0.0003% respectively. In this study, DNA from batches of 24 leaf segments measuring 0.5 cm from different plants or 1000 seeds could be conveniently extracted and accurately analysed. As part of assay validation, the comparative analysis of five geographically distinct Lolium populations with dCAPS and Q-PCR procedures demonstrated the accuracy of the latter method, and the three possible II1781, IL1781 and LL1781 ACCase genotypes being distributed as predicted by the Hardy-Weinberg principle. Given the dominance of the L1781 over the I1781 allele at recommended field rates for most ACCase inhibitors, the frequency of herbicide survivors in the field owing only to the presence of the I1781L mutation is thus predicted to be 2pq + q(2), where p and q are the frequencies of the I1781 and L1781 alleles as determined by Q-PCR. The Q-PCR assay established allows detection of very low levels of the L1781 ACCase mutation before resistance would normally be discernible in the field. Therefore, it offers the opportunity to tackle resistance at its very onset, potentially avoiding implementation of complicated and often costly weed management practices.     

Molecular characterisation of resistance to ALS-inhibiting herbicides in Hordeum leporinum biotypes

BACKGROUND: The acetolactate synthase (ALS)-inhibiting herbicide sulfosulfuron is registered in Australia for the selective control of Hordeum leporinum Link. in wheat crops. This herbicide failed to control H. leporinum on two farms in Western Australia on its first use. This study aimed to determine the level of resistance of three H. leporinum biotypes, identify the biochemical and molecular basis and develop molecular markers for diagnostic analysis of the resistance. RESULTS: Dose-response studies revealed very high level (>340-fold) resistance to the sulfonylurea herbicides sulfosulfuron and sulfometuron. In vitro ALS assays revealed that resistance was due to reduced sensitivity of the ALS enzyme to herbicide inhibition. This altered ALS sensitivity in the resistant biotypes was found to be due to a mutation in the ALS gene resulting in amino acid proline to serine substitution at position 197. In addition, two- to threefold higher ALS activities were consistently found in the resistant biotypes, compared with the known susceptible biotype. Two cleaved amplified polymorphic sequence (CAPS) markers were developed for diagnostic testing of the resistant populations. CONCLUSION: This study established the first documented case of evolved ALS inhibitor resistance in H. leporinum and revealed that the molecular basis of resistance is due to a Pro to Ser mutation in the ALS gene.     

靶标基因突变导致入侵性杂草长芒苋对咪唑乙烟酸产生抗性

长芒苋Amaranthus palmeri生长迅速,适应性广,繁殖系数高,具有很强的竞争性,已在我国多地定植,对作物产量及生态环境构成潜在威胁.一旦其对除草剂产生抗性,将大大增加治理难度.本试验研究了采自不同地点的长芒苋种群对除草剂咪唑乙烟酸的抗性水平和抗性机理.整株生物测定得出,长芒苋疑似抗性种群和敏感种群对咪唑乙烟...     

The role of fungal endophyte infection in the evolution of Lolium multiflorum resistance to diclofop-methyl

Diclofop-methyl resistance was evaluated in populations of Italian ryegrass ( Lolium multiflorum Lam.) infected and uninfected with fungal endophyte ( Neotyphodium ). Survival was tested in susceptible populations using herbicide screening. The results served as inputs to a model for investigating the role of endophyte infection in the evolution of L. multiflorum resistance to herbicide. The tolerance of infected plants varied depending on the origin of the population and the herbicide dose. Only in some populations and at some diclofop-methyl doses did plants infected with these endophytes have higher survivorship than endophyte-free plants. The model demonstrated that endophytes might indeed play an important role in the evolution of herbicide-resistant weeds, delaying the appearance of herbicide resistance.     

Development of herbicide resistance in weeds in a crop rotation with acetolactate synthase‐tolerant sugar beets under varying selection pressure

The development of acetolactate synthase (ALS) tolerant sugar beet provides new opportunities for weed control in sugar beet cultivation. The system consists of an ALS?inhibiting herbicide (foramsulfuron + thiencarbazone‐methyl) and a herbicide‐tolerant sugar beet variety. Previously, the use of ALS‐inhibitors in sugar beet was limited due to the susceptibility of the crop to active ingredients from this mode of action. The postulated benefits of cultivation of the ALS‐tolerant sugar beet are associated with potential risks. Up to now, with no relevant proportion of herbicide‐tolerant crops in Germany, ALS‐inhibitors are used in many different crops. An additional use in sugar beet cultivation could increase the selection pressure for ALS‐resistant weeds. To evaluate the impact of varying intensity of ALS‐inhibitor use on two weed species (Alopecurus myosuroides and Tripleurospermum perforatum) in a crop rotation, field trials were conducted in Germany in two locations from 2014 to 2017. Weed densities, genetic resistance background and crop yields were annually assessed. The results indicate that it is possible to control ALS‐resistant weeds with an adapted herbicide strategy in a crop rotation including herbicide‐tolerant sugar beet. According to the weed density and species, the herbicide strategy must be extended to graminicide treatment in sugar beet, and a residual herbicide must be used in winter wheat. The spread of resistant biotypes in our experiments could not be attributed to the integration of herbicide‐tolerant cultivars, although the application of ALS‐inhibitors promoted the development of resistant weed populations. Annual use of ALS‐inhibitors resulted in significant high weed densities and caused seriously yield losses. Genetic analysis of surviving weed plants confirmed the selection of ALS‐resistant biotypes.     

多花水苋对苄嘧磺隆的抗性水平及靶标抗性机制

为明确水稻田杂草多花水苋Ammannia multiflora对乙酰乳酸合成酶 (ALS) 抑制剂类除草剂苄嘧磺隆的抗性水平和抗性分子机制,采用整株水平测定法,测定了采自江苏省扬州市田间的多花水苋疑似抗性种群 (YZ-R) 对苄嘧磺隆的抗性指数,并分析了YZ-R种群和相对敏感种群 (YZ-S)多花水苋ALS酶对苄嘧磺隆的敏感性差异,同时比较了YZ-R和YZ-S种群ALS基因的核苷酸序列差异。结果表明:YZ-R种群多花水苋对苄嘧磺隆已表现出高水平抗性,其抗性指数 (RI) 为40.6;苄嘧磺隆对YZ-R种群ALS酶活性的抑制中浓度 (I₅₀) 为0.087 μmol/L,对YZ-S种群的I₅₀值为0.0028 μmol/L,其抗性指数为31.1。通过PCR扩增获得了多花水苋ALS基因的部分序列,该序列包含了已报道的8个氨基酸突变位点。ALS基因序列比对分析发现,YZ-R种群多花水苋植株ALS基因第197 位氨基酸由脯氨酸 (CCT) 突变为丝氨酸 (TCT)。研究表明,ALS基因发生脯氨酸 (Pro)-197-丝氨酸 (Ser) 的突变,导致多花水苋ALS酶对苄嘧磺隆的敏感性下降,是多花水苋YZ-R种群对苄嘧磺隆产生高水平抗性的主要原因。     

Multiple herbicide‐resistant Lolium rigidum (annual ryegrass) now dominates across the Western Australian grain belt

Lolium rigidum (annual or rigid ryegrass) is a widespread annual weed in cropping systems of southern Australia, and herbicide resistance in L. rigidum is a common problem in this region. In 2010, a random survey was conducted across the grain belt of Western Australia to determine the frequency of herbicide‐resistant L. rigidum populations and to compare this with the results of previous surveys in 1998 and 2003. During the survey, 466 cropping fields were visited, with a total of 362 L. rigidum populations collected. Screening of these populations with the herbicides commonly used for control of L. rigidum revealed that resistance to the ACCase‐ and ALS‐inhibiting herbicides was common, with 96% of populations having plants resistant to the ACCase herbicide diclofop‐methyl and 98% having plants resistant to the ALS herbicide sulfometuron. Resistance to another ACCase herbicide, clethodim, is increasing, with 65% of populations now containing resistant plants. Resistance to other herbicide modes of action was significantly lower, with 27% of populations containing plants with resistance to the pre‐emergent herbicide trifluralin, and glyphosate, atrazine and paraquat providing good control of most of the populations screened in this survey. Ninety five per cent of L. rigidum populations contained plants with resistance to at least two herbicide modes of action. These results demonstrate that resistance levels have increased dramatically for the ACCase‐ and ALS‐inhibiting herbicides since the last survey in 2003 (>95% vs. 70–90%); therefore, the use of a wide range of integrated weed management options are required to sustain these cropping systems in the future.     

杂草对乙酰乳酸合成酶抑制剂抗药性研究进展

乙酰乳酸合成酶(ALS)抑制剂类除草剂已经成为一类广泛使用的除草剂。综述了杂草对ALS抑制剂类除草剂抗药性的产生与发展、抗性机理、抗性基因应用等方面的研究进展。其抗性产生机理主要有杂草对除草剂代谢能力增强、ALS基因突变导致对除草剂敏感性降低和ALS含量提高等。     

小麦田看麦娘对甲基二磺隆的抗性水平及分子机制初探

看麦娘是中国长江中下游地区稻茬麦田的主要恶性杂草之一,甲基二磺隆是防治小麦田看麦娘等禾本科杂草的重要除草剂.该研究团队前期在安徽省凤台县小麦田采集到疑似抗性种群看麦娘(AHFT-01),为明确其对甲基二磺隆的抗性发生情况及潜在的抗性机制,采用温室盆栽法在整株水平上测定了该种群对甲基二磺隆及其他乙酰乳酸合成酶(ALS)抑...     

杂草对AHAS抑制剂的抗药性分子机理研究进展

除草剂在田间的重复及不合理使用,导致了杂草抗药性的发生和发展。其中AHAS抑制剂由于靶标单一,抗性发展十分迅速。截至2009年,已有103种杂草对AHAS抑制剂产生了抗药性,占19类化学除草剂总抗药性杂草生物型的近1/3。从AHAS基因突变位点及种类与杂草抗药性水平的关系、AHAS基因突变与AHAS酶活性的关系、AHAS基因拷贝数与杂草抗药性的关系以及AHAS酶与除草剂结合前后的三维结构等方面,综述了杂草对AHAS抑制剂产生抗药性的机理,旨在为AHAS抑制剂抗性研究提供参考。并对自然种群目标基因的等位基因检测技术(ECOTILLING)和衍生型酶切扩增多态性序列(dCAPS)两种通过检测等位基因多态性的手段快速诊断抗药性杂草的新技术进行了介绍,讨论了延缓杂草抗药性发生和发展的策略。     

Cross-resistance profile of mesosulfuron-methyl-resistant Italian ryegrass in the southern United States

Diclofop-resistant Lolium species (ryegrass) is a major weed problem in wheat production worldwide. This study was conducted to determine the resistance pattern of diclofop-resistant ryegrass accessions from the southern United States to mesosulfuron-methyl, a recently commercialized herbicide for ryegrass control in wheat; to determine the cross-resistance pattern of a Lolium multiflorum Lam. (Italian ryegrass) accession, 03-1, to acetolactate synthase (ALS) and acetyl-CoA carboxylase (ACCase) inhibitors; and to determine the resistance mechanism of Italian ryegrass to mesosulfuron-methyl. Seventeen ryegrass accessions from Arkansas and Louisiana, including standard resistant and susceptible accessions, were used in this experiment. Fourteen of the 17 accessions were more resistant (four- to > 308-fold) to diclofop than the standard susceptible biotype. One accession, 03-1, was resistant to mesosulfuron-methyl as well as to other ALS inhibitor herbicides such as chlorsulfuron, imazamox and sulfometuron. Accession 03-1, however, did not show multiple resistance to the ACCase inhibitor herbicides diclofop, fluazifop, clethodim, sethoxydim and pinoxaden, nor to glyphosate. The in vivo ALS activity of the 03-1 biotype was less affected by mesosulfuron-methyl than the susceptible biotype. This indicates that the resistance mechanism of Italian ryegrass to mesosulfuron-methyl is partly due to an alteration in the target enzyme, ALS. It is concluded that diclofop-resistant ryegrass in the southern United States can be generally controlled by mesosulfuron-methyl. However, mesosulfuron-methyl must be used with caution because not all ryegrass populations are susceptible to it. There is a need for more thorough profiling of ryegrass resistance to herbicides.     

Contamination of internationally traded wheat by herbicide‐resistant Lolium rigidum

As herbicide‐resistant weeds have spread in the agricultural fields of grain‐exporting countries, their seeds could be introduced into other countries as contaminants in imported grain. The spread of resistance genes through seed and pollen can cause significant economic loss. In order to assess the extent of the problem, we investigated the contamination by herbicide‐resistant annual ryegrass (Lolium rigidum) of wheat imported from Western Australia into Japan. Annual ryegrass seeds were recovered from wheat shipments and seed bioassays were conducted to identify resistance to the herbicides that are commonly used in Australia: diclofop‐methyl, sethoxydim, chlorsulfuron, and glyphosate. Nearly 4500 ryegrass seeds were detected in 20 kg of wheat that was imported in both 2006 and 2007. About 35% and 15% of the seeds were resistant to diclofop‐methyl, 5% and 6% were resistant to sethoxydim, and 56% and 60% were resistant to chlorsulfuron in 2006 and 2007, respectively. None was resistant to glyphosate in either year. As the contamination of crops by herbicide‐resistant weeds is probably a common phenomenon, the monitoring of incoming grain shipments is necessary to stem the further spread of herbicide‐resistant weeds into importing countries.     

Multiple resistance of Papaver rhoeas L. to 2,4‐D and acetolactate synthase inhibitors in four European countries

The issue of cross‐ or multiple resistance to acetolactate synthase (ALS) inhibitors and the auxinic herbicide 2,4‐D was investigated in Papaver rhoeas L., a common and troublesome weed in winter cereals, in a broad‐scale study across four European countries. A combination of herbicide sensitivity bioassays and molecular assays targeting mutations involved in resistance was conducted on 27 populations of P. rhoeas originating from Greece (9), Italy (5), France (10) and Spain (3). Plants resistant to the field rate of 2,4‐D were observed in 25 of the 27 populations assayed, in frequencies ranging from 5% to 85%. Plants resistant to ALS‐inhibiting herbicides (sulfonylureas) were present in 24 of the 27 populations, in frequencies ranging from 4% to 100%. Plants resistant to 2,4‐D co‐occurred with plants resistant to sulfonylureas in 23 populations. In four of these, the probability of presence of plants with cross‐ or multiple resistance to 2,4‐D and sulfonylureas was higher than 0.5. ALS genotyping of plants from the field populations or of their progenies, identified ALS alleles carrying a mutation at codon Pro197 or Trp574 in 2,4‐D‐sensitive and in 2,4‐D‐resistant plants. The latter case confirmed multiple resistance to 2,4‐D and ALS inhibitors at the level of individual plants in all four countries investigated. This study is the first to identify individual plants with multiple resistance in P. rhoeas, an attribute rarely assessed in other weed species, but one with significant implications in designing chemical control strategies.     

Development of near-isogenic lines and identification of markers linked to auxinic herbicide resistance in wild mustard (Sinapis arvensis L.)

BACKGROUND: Auxinic herbicides are widely used for selective control of many broadleaf weeds, e.g. wild mustard. An auxinic‐herbicide‐resistant wild mustard biotype may offer an excellent model system to elucidate the mechanism of action of these herbicides. Classical genetic analyses demonstrate that the wild mustard auxinic herbicide resistance is determined by a single dominant gene. Availability of near‐isogenic lines (NILs) of wild mustard with auxinic herbicide resistance (R) and herbicide susceptibility (S) will help to study the fitness penalty as well as the precise characterization of this gene. RESULTS: Eight generations of backcrosses were performed, and homozygous auxinic‐herbicide‐resistant and auxinic‐herbicide‐susceptible NILs were identified from BC₈F₃ families. S plants produced significantly more biomass and seed compared with R plants, suggesting that wild mustard auxinic herbicide resistance may result in fitness reduction. It was also found that the serrated margin of the first true leaf was closely linked to auxinic herbicide resistance. Using the introgressed progeny, molecular markers linked to auxinic herbicide resistance were identified, and a genetic map was constructed. CONCLUSION: The fitness penalty associated with the auxinic herbicide resistance gene may explain the relatively slow occurrence and spread of auxinic‐herbicide‐resistant weeds. The detection of the closely linked markers should hasten the identification and characterization of this gene. Copyright © 2012 Society of Chemical Industry     

Cross-resistance of Bidens subalternans to acetolactate synthase inhibitors in Brazil

Weeds resistant (R) to herbicides are widespread worldwide. Bidens subalternans is one of the most troublesome weeds in conventional soyabean fields in Brazil, and in a crop rotation system of cotton/soyabean and maize/soyabean some populations had evolved resistance to acetolactate synthase (ALS)-inhibiting herbicides. Bidens subalternans plants suspected of resistance were observed in soyabean fields where the main ALS-inhibiting herbicide sprayed is chlorimuron-ethyl. To confirm and characterise the resistance of B. subalternans to ALS inhibitors, whole-plant bioassays were conducted in 2006 and 2008. ALS in vivo enzyme bioassays were also conducted in 2007. In both bioassays, the R biotype showed cross-resistance to four chemical families of ALS-inhibiting herbicides. According to whole-plant level tests the R biotype showed 498-, 797-, 726- and >877-fold resistance to chlorimuron-ethyl, imazethapyr, cloransulam-methyl and pyrithiobac-sodium herbicides respectively. The R biotype was also 17-, 166-, 436- and 516-fold R to chlorimuron-ethyl, imazethapyr, cloransulam-methyl and pyrithiobac-sodium herbicides, respectively, based on the enzyme assay. Therefore, the herbicide-R B. subalternans can no longer be controlled by any ALS-inhibitor herbicides. Integrated control methods involving alternative herbicide with different modes of action are needed, to avoid yield losses in conventional soyabean fields in Brazil that are infested by ALS-R B. subalternans populations.     

玉米田反枝苋对烟嘧磺隆的抗性水平及靶标抗性分子机理

为明确玉米田主要杂草反枝苋对烟嘧磺隆的抗性水平及靶标抗性分子机理,采用整株水平测定法检测了黑龙江省玉米田反枝苋对烟嘧磺隆的抗性水平,通过靶标酶离体活性测定,分析了抗性和敏感种群反枝苋乙酰乳酸合成酶 (ALS) 对烟嘧磺隆的敏感性,并通过靶标ALS基因克隆测序进行了序列比对分析。结果显示:黑龙江省反枝苋疑似抗性种群 (HLJ-R) 对烟嘧磺隆已产生较高水平抗性,其抗性倍数达13.7;酶活性测定结果表明:烟嘧磺隆对HLJ-R种群ALS活性的抑制中浓度 (IC₅₀) 值是对敏感种群 (TA-S) IC₅₀值的43.9倍;与TA-S种群相比,HLJ-R种群ALS基因205位丙氨酸突变为缬氨酸,574位色氨酸突变为亮氨酸。研究表明,黑龙江省玉米田反枝苋对烟嘧磺隆已产生较高水平抗性,且靶标ALS基因的突变可能是其抗性产生的主要原因之一。