Characterisation of Avena fatua populations with resistance to multiple herbicides

Avena fatua (wild oat) populations with resistance (R) to one or more herbicides have been described in numerous cropping systems worldwide. We previously reported that the R3 and R4 wild oat populations from Montana, USA, were resistant to four herbicides representing three different modes of action: tralkoxydim [acetyl‐CoA carboxylase (ACCase] inhibitor), imazamethabenz and flucarbazone [acetolactate synthase (ALS) inhibitors] and difenzoquat (growth inhibitor). We now quantify resistance levels of these populations to triallate [very long chain fatty acid (VLCFA) biosynthesis inhibitor], pinoxaden (ACCase inhibitor) and paraquat (photosystem I inhibitor). Glasshouse dose–response experiments showed that, compared with the means of two susceptible (S) populations, the R3 and R4 populations were 17.5‐ and 18.1‐fold more resistant to triallate, 3.6‐ and 3.7‐fold more resistant to pinoxaden, respectively, and 3.2‐fold (R3) more resistant to paraquat. Pre‐treatment of R plants with the cytochrome P450 inhibitor malathion partially reversed the resistance phenotype for flucarbazone (both populations), imazamethabenz (R4), difenzoquat (R4) and pinoxaden (R3), but not for tralkoxydim, fenoxaprop‐P‐ethyl or triallate. Target site point mutations known to confer resistance to ALS or ACCase inhibitors were not detected via DNA sequencing and allele‐specific PCR assays in R plants, suggesting the involvement of non‐target site resistance mechanism(s) for these herbicides. Together, our results complete the initial characterisation of wild oat populations that are resistant to seven (R3) or six (R4) herbicides from five or four mode of action families respectively.     

Chemical control of herbicide-resistant Lolium rigidum Gaud. in north-eastern Spain

BACKGROUND: Lolium rigidum Gaud. is one of the most common weed species in winter cereals in north‐eastern Spain, with populations that have evolved resistance to herbicides becoming more widespread since the mid‐1990s. Nine trials on commercial fields with herbicide‐resistant L. rigidum were conducted during the cropping seasons 2001–2002 to 2003–2004, testing the efficacy of 20 herbicides and mixtures pre‐ and post‐emergence and as sequential applications. Weed populations chosen had different resistance patterns to chlortoluron, chlorsulfuron, diclofop‐methyl and tralkoxydim, representative of the resistance problems faced by farmers. RESULTS: In pre‐emergence, prosulfocarb mixed with trifluralin, chlortoluron or triasulfuron was effective on six populations. In post‐emergence, iodosulfuron alone or mixed with mesosulfuron gave the best results but did not control three resistant populations. At Ferran 1, none of the herbicide combinations reached 90% efficacy. CONCLUSIONS: The diverse efficacy patterns of the different populations demonstrate the need for detailed knowledge of the populations before using herbicides. Moreover, the unexpected insufficient efficacy of the new herbicide iodosulfuron prior to its field use shows the need to combine herbicides with other non‐chemical weed control methods to control resistant L. rigidum in north‐eastern Spain. Copyright © 2010 Society of Chemical Industry     

Characterisation and molecular basis of ALS inhibitor resistance in the grass weed Alopecurus myosuroides

Several UK populations of the grass weed Alopecurus myosuroides were identified where high proportions of individuals showed resistance to the acetolactate synthase (ALS)‐inhibiting herbicides, mesosulfuron‐methyl + iodosulfuron‐methyl sodium mixture and sulfometuron‐methyl. Screening with sulfometuron, followed by DNA sequencing of the ALS gene from resistant and susceptible individuals, led to the identification of eight populations where a single point mutation segregated with resistance to sulfometuron. All highly resistant individuals from seven of eight populations showed a single‐nucleotide polymorphism (SNP) in the first position of the Pro197 codon of an A. myosuroides ALS gene, conferring a predicted proline to threonine target‐site change. One population showed resistant individuals with single‐nucleotide polymorphism in the second position of the Trp574 codon, conferring a predicted tryptophan to leucine substitution. No other mutations segregating with resistance were found. Enzyme assays confirmed that resistance was due to an altered form of ALS enzyme, which was less susceptible to inhibition by sulfonylureas, making this one of the first fully characterised cases of ALS target‐site resistance in a European grass weed. Increased information regarding the nature and distribution of ALS target‐site mutation may help support sustainable management strategies, allowing continued use of mesosulfuron + iodosulfuron against this weed in the UK.     

7种苗后除草剂对菵草的除草活性以及对小麦的安全性评价

为了筛选对菵草高效且对小麦安全的除草剂品种,采用温室盆栽法测定了 7种苗后除草剂对菵草的除草活性以及对小麦的安全性.结果表明,5％唑啉草酯EC和15％炔草酯WP对菵草防效优异,ED90仅为各自田间登记低剂量的1/3和1/2;50％异丙隆WP和7.5％啶磺草胺WG对菵草防效较好,ED90与各自田间登记高剂量相当;69 g...     

The response of ACCase-resistant Phalaris paradoxa populations involves two different target site mutations

Phalaris paradoxa (awned canary-grass) is an aggressive annual winter weed in wheat and other arable crops that is controlled mainly by ACCase-inhibiting herbicides: cyclohexanediones (DIMs), aryloxyphenoxypropionates (FOPs) and phenylpyrazolines (DENs, e.g. pinoxaden). The selection pressure imposed on the weed populations by repeated use of these herbicides has resulted in the evolution of increased numbers of ACCase-resistant populations of P. paradoxa in Israel and other countries. Two populations, Revadim (RV) and Mishmar Ha'emek (MH) that were exposed to differing weed and crop management tactics were investigated. Both populations were highly resistant to all FOPs, pinoxaden and cycloxydim, but responded differently to some DIMs. RV plants exhibited much higher resistance to tralkoxydim than MH plants, while showing similar low levels of resistance to tepraloxydim and clethodim. Both populations were equally susceptible to graminicides with other modes of action. The mutations responsible for the observed resistance were identified using PCR-RFLP and by sequencing the carboxyl transferase domain of the chloroplastic ACCase gene. RV plants possess a substitution of Asp₂₀₇₈ to Gly, whereas in MH population a mixture of Ile₂₀₄₁ to Asn or Asp₂₀₇₈ to Gly was found. Our study demonstrates that lack of herbicide and crop rotation may result in the evolution of diverse target site mutations and differential response of the whole plant to ACCase inhibitors.     

啶磺草胺等8种除草剂对小麦田8种禾本科杂草的生物活性

在温室内采用盆栽整株喷雾法研究了啶磺草胺等8种除草剂对雀麦、节节麦等8种禾本科杂草的生物活性,探讨各除草剂对这些禾本科杂草的防除谱及防除效果。结果表明：啶磺草胺、氟唑磺隆和甲基二磺隆对雀麦、日本看麦娘和看麦娘的防效均较好,田间推荐剂量下（14、22.5、9 g/hm2）防效为66.74%～100%;对硬草的防效略差;对野燕麦和节节麦的防效较差;对菵草、蜡烛草略有差异,氟唑磺隆对菵草防效较好,而啶磺草胺对蜡烛草防效较好。唑啉草酯、肟草酮、炔草酯、精恶唑禾草灵和异丙隆对日本看麦娘、看麦娘、蜡烛草、硬草、菵草和野燕麦防效均较好,田间推荐剂量下防效为71.73%～100%,对节节麦、雀麦防效较差或无效。     

Cross-resistance patterns of winter wild oat (<Emphasis Type="Italic">Avena ludoviciana</Emphasis>) populations to ACCase inhibitor herbicides

The level of resistance and patterns of cross-resistance to clodinafop, sethoxydim, and pinoxaden were examined in 12 putative resistant and one susceptible populations of winter wild oat (Avena ludoviciana) collected from Fars Province, in the southwest of Iran. The responses of biomass and length of coleoptiles to the increasing dosages of the three herbicides were determined in both whole-plant and seed bioassays. In the whole-plant bioassay, all 12 putative resistant populations were found to be resistant to clodinafop with resistance ratios (R/S) ranging from 1.76 to >47.04. Most clodinafop-resistant populations exhibited low levels of cross-resistance to sethoxydim. Three highly sethoxydim-resistant populations, F2, S2, and ES4, were slightly resistant to clodinafop. Six populations (M1, M2, F2, S2, S4, and ES4) showed high cross-resistance to pinoxaden with R/S values as large as 10.73 to 40.29. A highly clodinafop-resistant population, M2, was more sensitive to pinoxaden than the susceptible population. The results of the seed bioassay resembled those obtained from the whole-plant experiment suggesting seed bioassay as an inexpensive, rapid method for screening-resistant genotypes.     

新疆南部地区冬麦田杂草的发生与防治

当前影响南疆地区冬麦田的杂草主要有藜、播娘蒿、萹蓄、大蓟、涩荠菜、苦苣菜、田旋花、稗草、硬草等。阔叶杂草防除可选用苯磺隆、氯氟吡氧乙酸等药剂,禾本科杂草防除可选用精恶唑禾草灵、炔草酯、唑啉草酯·炔草酸等除草剂。在杂草混合危害的麦田,可选用苯磺隆与唑啉草酯·炔草酸或精禾草灵混配进行防除。施药时应采取二次稀释的方法,兑水量一般不少于450 kg／hm^2。     

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     

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...     

耿氏硬草对乙酰辅酶A羧化酶类除草剂抗性水平及分子机制初探

为明确耿氏硬草Pseudosclerochloa kengiana(Ohwi)Tzvel潜在抗性种群对不同乙酰辅酶A羧化酶(ACCase)类除草剂的抗性水平及其靶标抗性的分子机制,采用剂量-反应曲线法测定了耿氏硬草对精鰁唑禾草灵、炔草酯、烯禾啶、烯草酮和唑啉草酯5种ACCase类除草剂的抗性水平,扩增并比对了耿氏硬草抗性和敏感种群间ACCase基因的差异。结果显示:与敏感种群SD-6相比,耿氏硬草种群SD-32对精鰁唑禾草灵、炔草酯、烯禾啶、烯草酮和唑啉草酯产生了不同水平的抗性,抗性倍数分别为16.5、7.5、15.0、4.4和5.7;SD-32种群ACCase基因CT区域的2078位氨基酸基因由GAT突变为GGT,导致天冬氨酸(Asp)被甘氨酸(Gly)取代。分析表明,ACCase基因2078位氨基酸的突变可能是导致耿氏硬草对ACCase类除草剂产生抗性的重要原因之一。     

Biochemical mechanisms of cross-resistance to aryloxyphenoxypropionate and cyclohexanedione herbicides in populations of Avena spp.

Aryloxyphenoxypropionate (APP) and cyclohexanedione (CHD) herbicides are used extensively in the UK to control grass weeds, including Avena spp. (wild-oats). Reports of resistance to APP and CHD herbicides are a particular concern for the agricultural community. In this study, the responses of four UK Avena populations were characterized towards the APP herbicides fenoxaprop-P-ethyl and fluazifop-P-butyl, and towards the CHD herbicides cycloxydim and tralkoxydim. An A. sterilis ssp. ludoviciana population (T/41) was found to be highly resistant to fenoxaprop-P-ethyl and fluazifop-P-butyl, but did not show cross-resistance to cycloxydim and tralkoxydim. In contrast, one A. sterilis ssp. ludoviciana (T/11) and one A. fatua population (Dorset) showed partial resistance to both APP herbicides and also showed cross-resistance to the CHD herbicide tralkoxydim, but not to cycloxydim. Before this study, the biochemical mechanisms that confer resistance to the APP and CHD herbicides in UK Avena populations were unknown. Results from the present study show that an enhanced rate of metabolism of fenoxaprop-P-ethyl was found to confer resistance in the two partially resistant Avena populations (T/11 and Dorset), and the presence of an insensitive form of the target enzyme, ACCase, was responsible for target site resistance to fenoxaprop-P-ethyl and fluazifop-P-butyl in the highly resistant population T/41. Cross-resistance to the CHD herbicide tralkoxydim in the T/11 and Dorset populations was not conferred by insensitive ACCase, and was most probably caused by enhanced metabolism. This is the first report that resistance to fenoxaprop-P-ethyl can be conferred by enhanced metabolism in Avena spp.     

Allelic variation of the ACCase gene and response to ACCase-inhibiting herbicides in pinoxaden-resistant Lolium spp

BACKGROUND: The repeated use of acetyl‐coenzyme A carboxylase (ACCase) inhibiting herbicides to control grass weeds has selected for resistance in Lolium spp. populations in Italy. The efficacy of pinoxaden, a recently marketed phenylpyrazoline herbicide, is of concern where resistance to ACCase inhibitors has already been ascertained. ACCase mutations associated with pinoxaden resistance were investigated, and the cross‐resistance pattern to clodinafop, haloxyfop, sethoxydim, clethodim and pinoxaden was established on homo/heterozygous plants for four mutant ACCase alleles. RESULTS: Seven different mutant ACCase alleles (1781‐Leu, 1999‐Leu, 2041‐Asn, 2041‐Val, 2078‐Gly, 2088‐Arg and 2096‐Ala) and 13 combinations with two types of mutation were detected in the pinoxaden‐resistant plants. The 1781‐Leu allele appears to confer a dominant resistance to pinoxaden, clodinafop, haloxyfop, sethoxydim and clethodim at 60 g AI ha^?1. The 2041‐Asn and 2041‐Val alleles are associated with dominant or partially dominant resistance to FOPs, no substantial resistance to DIMs and a moderate resistance to pinoxaden. The 2088‐Arg allele endows a partially dominant resistance to clodinafop, sethoxydim and most likely to pinoxaden. In addition, non‐target‐site resistance mechanisms seem to be involved in pinoxaden resistance. CONCLUSION: Almost all the ACCase mutations selected in the field by other ACCase inhibitors are likely to confer resistance to pinoxaden. Although pinoxaden is sometimes able to control FOP‐resistant populations, it should not be considered as a sustainable ACCase resistance management tool. The presence of non‐ACCase‐based resistance mechanisms that could confer resistance to herbicides with different modes of action further complicates the resistance management strategies. Copyright © 2011 Society of Chemical Industry     

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。     

Mechanism of resistance to fenoxaprop in Japanese foxtail (Alopecurus japonicus) from China

Japanese foxtail is one of the most common and troublesome weeds infesting cereal and oilseed rape fields in China. Repeated use during the last three decades of the ACCase-inhibiting herbicide fenoxaprop-P-ethyl to control this weed has resulted in the occurrence of resistance. Dose–response tests established that a population (AHFD-1) from eastern China had evolved high-level resistance to fenoxaprop-P-ethyl. Based on the resistance index, this resistant population of A. japonicus is 60.31-fold resistant to fenoxaprop-P-ethyl. Subsequently, only a tryptophan to cysteine substitution was identified to confer resistance to fenoxaprop-P-ethyl in this resistant population. ACCase activity tests further confirmed this substitution was linked to resistance. This is the first report of the occurrence of Trp-2027-Cys substitution of ACCase in A. japonicus. From whole-plant pot dose–response tests, we confirmed that this population conferred resistance to other APP herbicides, including clodinafop-propargyl, fluazifop-P-butyl, quizalofop-P-ethyl, haloxyfop-R-methyl, cyhalofop-butyl, metamifop, DEN herbicide pinoxaden, but not to CHD herbicides clethodim, sethoxydim. There was also no resistance observed to ALS-inhibiting herbicides sulfosulfuron, mesosulfuron-methyl, flucarbazone-sodium, pyroxsulam, Triazine herbicide prometryne and glyphosate. However, this resistant population was likely to confer slightly (or no) resistant to Urea herbicides chlortoluron and isoproturon.     

Segregation of non‐target‐site resistance to herbicides in multiple‐resistant Alopecurus myosuroides plants

Non‐target‐site resistance (NTSR) comprises a set of mechanisms conferring resistance to multiple modes of action. Investigation of the number of loci involved in NTSR will aid in the understanding of these resistance mechanisms. Therefore, six different multiple herbicide‐resistant Alopecurus myosuroides plants with different herbicide history were crossed in two generations with a susceptible wild type. Seeds from the backcrossing generation were studied for their segregation rate for resistance to five herbicides with four different modes of action (HRAC groups C₂, A, B and K₃). Taking into account that NTSR is a set of quantitative traits, the numbers of loci controlling NTSR were estimated using a normal mixture model fitted by the NLMIXED procedure of SAS. Each herbicide was controlled by a different number of loci comparing the six plants. In most of the cases, chlorotoluron resistance was controlled by one locus, whereas resistance to fenoxaprop‐P‐ethyl needed one or two loci. Resistance to pinoxaden was in all plants conferred by two loci. Cross‐resistance of fenoxaprop‐P‐ethyl and pinoxaden was found in all backcrossings, indicating that at least one of the two loci is responsible for both resistances. Resistance to mesosulfuron + iodosulfuron was conferred by a minimum of two loci. Results indicated that a minimum of five different loci can be involved in a multiple NTSR plant. Furthermore, the plant‐specific accumulation of NTSR loci was demonstrated. Such behaviour should be taken into account when evaluating the development and further spread of herbicide resistance.     

麦田茼草春季化学防除技术研究

通过田间试验筛选春季有效防除麦田茼草的除草剂配方。结果表明,40％肟草酮水分散粒剂60g／667m2＋50％异丙隆可湿性粉剂100g／667m2、7．5％啶磺草胺水分散粒剂11g／667m2＋30g／L甲基二磺隆油悬剂12g／667m2、40％肟草酮水分散粒剂60g／667m2＋30g／L甲基二磺隆油悬剂20g／667m。处理均可用于春季小麦田蔺草的有效防除,且对小麦相对安全。     

野燕麦对精噁唑禾草灵、炔草酯敏感性差异测定

为明确不同野燕麦种群对精噁唑禾草灵和炔草酯的敏感性水平,采用整株生物测定与种子生物测定分别检测了河南、湖北、江苏三省共11个野燕麦种群对精噁唑禾草灵和炔草酯的敏感性。结果表明,2种测定方法获得的野燕麦种群对2种除草剂的敏感性基本一致。整株生物测定结果显示,不同野燕麦种群对精噁唑禾草灵和炔草酸的敏感性存在显著差异,其中,金水闸野燕麦种群对精噁唑禾草灵和炔草酯敏感性最高,其GR50值（有效成分）分别为2.46、3.65 g/hm2,而辉县野燕麦种群对精噁唑禾草灵和炔草酯敏感性最低,GR50值（有效成分）分别为15.00、23.12 g/hm2,其余野燕麦种群对精噁唑禾草灵和炔草酯的敏感性介于金水闸种群与辉县种群之间。种子生物测定结果与整株生物测定结果趋势一致,但表现出的敏感性略高。     

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。     

Chlorophyll fluorescence imaging: a new method for rapid detection of herbicide resistance in Alopecurus myosuroides

Due to the steadily increasing number of putative herbicide‐resistant weed populations, the demand for rapid in‐season tests is rising. In this study, we introduce a new quantitative herbicide‐resistance test system based on chlorophyll fluorescence imaging analysis of photosynthesis‐related parameters. Susceptible and herbicide‐resistant populations of Alopecurus myosuroides (black‐grass) were cultivated in multiwell tissue culture plates containing nutrient agar and different dosages of fenoxaprop‐P‐ethyl and mesosulfuron+iodosulfuron. The maximum quantum efficiency of the PSII was measured 3 h after transplanting (HAT) and then for seven days every 24 h. Data of maximum quantum efficiency of the PSII were compared with standard whole‐plant pot tests and molecular tests for target‐site mutations. It was possible to fit dose‐response curves and calculate corresponding resistance factors for ED90 for all populations tested using the chlorophyll fluorescence imaging. It was possible to distinguish between resistant and susceptible populations. The results of the chlorophyll fluorescence imaging corresponded well with the standard whole‐plant pot tests in the glasshouse. However, populations with proved target‐site mutations did not differ from other herbicide‐resistant populations in the maximum quantum efficiency values of the PSII. We conclude that the chlorophyll fluorescence imaging provides reliable data on herbicide resistance for both modes of action tested in a shorter time and using less space, compared with standard whole‐plant pot tests in the glasshouse.