Resistance of Camelina microcarpa to acetolactate synthase inhibiting herbicides

An accession of Camelina microcarpa suspected to be resistant to sulfonylurea herbicides was identified in Oregon in 1998 field experiments. Greenhouse research confirmed that the putative resistant biotype was resistant to chlorsulfuron and metsulfuron on a whole plant level. Compared with the resistant (R) biotype, the susceptible (S) biotype was 1000 and 10 000‐fold more sensitive to metsulfuron and chlorsulfuron respectively. The R biotype was also resistant to other sulfonylurea, sulfonylaminocarbonyl‐triazolinone, imidazolinone and triazolopyrimidine herbicides. An in vivo enzyme assay indicated that acetolactate synthase (ALS) from the R plants required 111 times more chlorsulfuron to inhibit activity by 50% compared with the amount required to have a similar effect on ALS from S plants. Analysis of the nucleotide and amino acid sequences demonstrated that a single‐point mutation from G to T in the als1 gene conferred the change from the amino acid tryptophan to leucine at position 572 in the resistant biotype. This research confirmed that ALS inhibitor resistance in an Oregon accession of C. microcarpa is based on an altered target site conferred by a single‐point mutation.     

Response of an acetolactate synthase (ALS)-resistant biotype of Amaranthus rudis to selected ALS-inhibiting and alternative herbicides

An Amaranthus rudis Saner (common water-hemp) biotype from a field treated for two consecutive years with a mixture of chlorimuron and metribuzin was tested in greenhouse and laboratory studies to assess resistance and cross-resistance to four acetolactale synthase (ALS)-inhibiting herbicides. The biotype demonstrated >1920-fold resistance at the whole plant level, and >850-fold resistance at the ALS enzyme to chlorimuron, compared with a susceptible biotype. This chlorimuron-resistant biotype was also cross-resistant to primisuifu-ron, haiosulfuron and imazethapyr. In greenhouse studies, atrazine alone or in combination with ALS-inhibiting herbicides provided excellent control of the resistant biotype of A. rudis . Combinations of dicamba and ALS-inhibitors also provided adequate control. Additionally, premixtures of flumetsulam and metolachlor and of dicamba and atrazine furnished excellent control of this chlorimuron-resistant A. rudis biotype.     

Occurrence,resistance factors and cross-resistance patterns to herbicides inhibiting acetolactate synthase (ALS) of Echinochloa crus-galli (L.) Pal. Beauv. in Central Europe

Journal of Plant Diseases and Protection - Echinochloa crus-galli (L.) Pal. Beauv. is one of the most noxious weeds in maize cultivation and has evolved target-site resistance to ALS-inhibiting...     

Transformation a mutant Monochoria vaginalis acetolactate synthase (ALS) gene renders Arabidopsis thaliana resistant to ALS inhibitors

Acetolactate synthase (ALS) genes from Monochoria vaginalis resistant (R) and susceptible (S) biotypes against ALS inhibitors found in Korea revealed a single amino acid substitution of Proline (CCT), at 169th position based on the M. vaginalis ALS sequence numbering, to serine (TCT) in conserved domain A of the gene (equal to the proline 197 in Arabidopsis thaliana ALS gene sequence). A. thaliana plants transformed with the single mutated (Pro₁₆₉ to Ser) M. vaginalis ALS gene (including transit signal peptide) showed cross-resistance patterns to ALS-inhibiting herbicides, like as sulfonylurea-herbicide bensulfuron methyl (R/S factor of 9.5), imidazolinone-herbicide imazapyr (R/S factor of 5.1), and triazolopyrimidine-herbicide flumetsulam (R/S factor of 17.6) when measuring hypocotyls’ length of A. thaliana. The ALS activity from the transgenic A. thaliana plants confirmed the cross-resistance pattern to these herbicides like as R/S factor of 8.3 to bensulfuron methyl, 2.3 to imazapyr, and 13.2 to flumetsulam.     

除草剂防除马尼拉草坪杂草试验

草坪宁1号7g/666.7m^2药后35d,60d的总体防效分别为90．8％和70．5％,明显高于阿特拉津100ml 都尔80ml/666.7m^2和阿特拉津100ml 乙草胺80ml/666.7m^2 2处理,对马尼拉草坪安全,值得推广。     

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.     

七种除草剂对水稻旱育抛栽大田杂草防除试验

水稻旱育抛栽大田秧苗叶龄小,人工除草难度大,对化学除草剂的安全性要求高,为了筛选适合本地推广使用的除草剂品种,１９９８年我们在中稻上进行了小区试验及部分品种的大田示范,现将试验结果整理如下。１材料与方法１．１供试药剂及用量用法每６６７ｍ２５％丁草胺颗...     

Tolerance to acetolactate synthase and acetyl-coenzyme A carboxylase inhibiting herbicides in Vulpia bromoides is conferred by two co-existing resistance mechanisms

Vulpia bromoides is a grass species naturally tolerant to acetolactate synthase (ALS) and acetyl-coenzyme A carboxylase (ACCase) inhibiting herbicides. The mechanism of tolerance to ALS herbicides was determined as cytochrome P450-monooxygenase mediated metabolic detoxification. The ALS enzyme extract partially purified from V. bromoides shoot tissue was found to be as sensitive as that of herbicide susceptible Lolium rigidum to ALS-inhibiting sulfonylurea (SU), triazolopyrimidine (TP), and imidazolinone (IM) herbicides. Furthermore, phytotoxicity of the wheat-selective SU herbicide chlorsulfuron was significantly enhanced in vivo in the presence of the known P450 inhibitor malathion. In contract, the biochemical basis of tolerance to ACCase inhibiting herbicides was established as an insensitive ACCase. In vitro ACCase inhibition assays showed that, compared to a herbicide susceptible L. rigidum, the V. bromoides ACCase was moderately (4.5- to 9.5-fold) insensitive to the aryloxyphenoxypropionate (APP) herbicides diclofop, fluazifop, and haloxyfop and highly insensitive (20- to >71-fold) to the cyclohexanedione (CHD) herbicides sethoxydim and tralkoxydim. No differential absorption or de-esterification of fluazifop-P-butyl was observed between the two species at 48 h after herbicide application, and furthermore V. bromoides did not detoxify fluazifop acid as rapidly as susceptible L. rigidum. It is concluded that two co-existing resistance mechanisms, i.e., an enhanced metabolism of ALS herbicides and an insensitive target ACCase, endow natural tolerance to ALS and ACCase inhibiting herbicides in V. bromoides.     

中稻抛秧田化学除草剂筛选试验

抛秧作为一种新的栽培方式,以其省种省工增产的优势被广大群众接受,栽培面积不断扩大。但是由于抛秧田秧苗与杂草同步生长,杂交稻秧苗数量少,杂草数量多;秧田前期浅水灌溉,肥料较多,阳光充足,十分有利于杂草萌发生长。本市抛秧田主要杂草是稗草、四叶萍、眼子菜、...     

几种除草剂对大麻田杂草的防效

对大麻安全性最低的除草剂是48%地乐胺EC,苗后7 d受害株率为23%。50%乙草胺EC和96%精异丙甲草胺EC对大麻的药害较轻。对大麻株高影响最大的是48%地乐胺EC,药后7 d和14 d的株高均显著低于空白对照,其他处理均接近空白对照。药后15 d对大麻田杂草的株防效最好的是96%精异丙甲草胺EC和50%乙草胺EC,分别为90.7%和89.8%,显著高于25%扑草净WP的79.7%和48%地乐胺EC的77.5%。药后30 d各处理对杂草的株防效都略有下降,但趋势基本一致。对大麻田杂草鲜重防效最好的除草剂为96%精异丙甲草胺EC和50%乙草胺EC,鲜重防效分别达到了89.4%和89.1%。在保证对大麻安全的前提下,96%精异丙甲草胺EC 1 050 mL/hm2和50%乙草胺EC 750 mL/hm2均可作为大麻田播后苗前除草剂使用,且能对杂草起到良好的防除效果。     

油菜田杂草的发生特点及防除药剂筛选

2000～2001年我们进行了油菜田杂草的田间消长规律观察及不同药剂防除油菜田杂草的田间试验，现将调查及试验结果报告如下。     

杂草对ALS抑制剂抗药性概述

随着化学除草剂的广泛、重复使用,导致抗药性杂草不断发生和发展。其中,抗ALS抑制剂杂草最多,约占抗药性杂草总量的三分之一。抗药性杂草严重威胁杂草治理和农业生产,引起了广泛的关注。文章概述了抗ALS抑制剂杂草的发生现状和抗性机制,以期为抗药性杂草研究和治理提供参考。     

不同药剂控制油菜田杂草效果

油菜是吴江市主要经济作物,常年种植面积均在13000hm2以上。自20世纪90年代以来,由于长期单一使用精禾草克防治看麦娘,导致油菜田杂草草相发生了明显变化,以繁缕为主的双子叶杂草上升为主要优势种,给油菜生产带来了威胁。为了寻找适合于吴江市目前油菜田杂草草相的安全、高效新     

夏玉米田除草剂筛选试验报告

近年来，除草剂的使用面积逐渐扩大，并广泛应用于各种作物田，以其省工省时、简单高效快速而深受欢迎。但在实际应用中也存在一些问题，比如一些除草剂杀草谱窄，残留量高。为确保河南洛阳地区夏玉米田除草剂的安全使用，我们进行了夏玉米田不同除草剂筛选试验。     

除草剂防除狗牙根草坪阔叶杂草试验

应用L9(34)正交表设计方案对56%2甲4氯钠、14%水花生净乳油及10%新得力三种除草剂混用的最佳配比,防除狗牙根草坪阔叶杂草,可扩大杀草谱,增强药效,降低残留。56%2甲4氯钠单剂防除猪殃殃的效果不理想,但与10%新得力混用,防除效果大大提高。     

Discovery of single-nucleotide mutations in acetolactate synthase genes by Ecotilling

TILLING (Targeting Induced Local Lesions IN Genomes) is a powerful reverse genetic technique that employs a mismatch-specific endonuclease to discover induced point mutations in genes of interest. The use of the TILLING technique to survey natural variation in genes is called Ecotilling. We report an adaptation of Ecotilling for rapid detection of single-nucleotide mutations in the acetolactate synthase (ALS) genes of sulfonylurea (SU)-resistant (R) Monochoria vaginalis (Pontederiaceae), a paddy weed, in Japan. Genomic DNA of a SU-R plant (target DNA) was mixed with the DNA of a SU-susceptible (S) plant (reference DNA). Ecotilling detected two nucleotide mutations in the ALS gene of SU-R M. vaginalis. These 2 mutations were confirmed by DNA sequencing. A single nucleotide mutation (C to A), in the codon CCT to CAT and another mutation (C to T), in the codon CCT to TCT were identified by sequencing. Both mutations result in the disruption of a Pro codon in the conserved Domain A region with the consequent substitution of a His residue in the first mutation and a Ser residue in the second. Substitution of the Pro residue in Domain A of the ALS gene has been reported to result in insensitivity to SUs in many weed biotypes. This study demonstrates that Ecotilling is a fast, reliable, economical method for detecting single-nucleotide mutations in genes arising from herbicide selection.     

几种除草剂混用对亚麻田杂草的防除效果

对3种混用除草剂防除南方亚麻田杂草进行了试验。试验结果表明,金都乐+2甲4氯钠、金都乐+高效盖草能、乙草胺+烯草酮3种混用除草剂可有效扩大杀草谱,提高防除效果,可以在南方亚麻田推广应用。     

不同药剂防除油菜田杂草试验初报

随着种植业结构的调整 ,油菜种植面积不断扩大 ,其杂草防除的好坏直接影响到油菜籽的品质和产量。为了有效地防除油菜田杂草 ,为大面积生产提供科学依据 ,我站进行了相关田间试验 ,取得明显的效果。1　材料与方法1 1　供试药剂( 1 ) 4%喷特ＥＣ(美国有利来路公司提供 ) ;( 2 ) 1 0 8%高效盖草能ＥＣ(美国陶氏益农公司提供 ) ;( 3) 30 %好实多ＥＣ(江苏农药研究所苏研公司提供 ) ;( 4) 1 7 5%林克ＥＣ(江苏农药研究所苏研公司提供 )。1 2　试验处理试验共设 9个处理 :( 1 ) 4%喷特ＥＣ40ｍｌ/亩 ;( 2 ) 4%喷特ＥＣ50ｍｌ/亩 ;( 3) 4%喷特…