Multiple Herbicide-Resistant Weeds and Non-target Site Resistance Mechanisms: A Global Challenge for Food Production PDF Download

Author: Joel Torra
Publisher: Frontiers Media SA
ISBN: 2889719081
Category : Science
Languages : en
Pages : 174

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Author: Zvonko Pacanoski
Publisher: BoD – Books on Demand
ISBN: 9535135554
Category : Technology & Engineering
Languages : en
Pages : 188

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Book Description
Herbicides are the dominant technology and the most effective weed control tools ever developed that are used for the control of weeds that infest crops. Over the last several decades, in situations of intense herbicide usage, there have been many examples of the evolution of weed populations resistant to herbicides. Weed adaptations to management tactics, including biochemical mimicry in the form of evolved resistance to the herbicides used for weed control, have increased rapidly throughout agriculture and now threaten global food security. Nowadays, expended space of research activities remains to focus on the herbicide resistance to weeds and crops. The authors of Herbicide Resistance in Weeds and Crops cover various issues regarding the present relevant research.

Author: National Research Council
Publisher: National Academies Press
ISBN: 0309265568
Category : Technology & Engineering
Languages : en
Pages : 67

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Book Description
Preserving the efficacy of herbicides and of herbicide-resistance technology depends on awareness of the increasing resistance of weeds to herbicides used in agriculture and coordinated action to address the problem by individuals at the farm level and beyond. This summit served as a venue to bring the attention of important stakeholders to the issue and as an opportunity for experts from diverse disciplines to strategize in a coordinated way to address herbicide-resistant weeds. In convening stakeholders for this event, participants took a step toward a recommendation from the 2010 National Research Council report The Impact of Genetically Engineered Crops on Farm Sustainability in the United States that federal and state government agencies, private-sector technology developers, universities, farmer organizations, and other relevant stakeholders collaborate to document emerging weed-resistance problems and to develop cost-effective resistance-management programs and practices that preserve effective weed control. The summit provided the opportunity for stakeholders to explore the scientific basis of the emergence of herbicide resistance and to consider different perspectives on both opportunities and barriers to overcoming the problem of herbicide-resistant weeds. National Summit on Strategies to Manage Herbicide-Resistant Weeds contains a brief synopsis of key points made by each speaker at the summit.

Author: Hugh J Beckie
Publisher:
ISBN: 9783039360086
Category :
Languages : en
Pages : 196

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Book Description
Today, herbicide-resistant weeds dominate research and development efforts in the discipline of weed science. The incidence, management challenges, and cost of multiple herbicide-resistant weed populations are continually increasing worldwide. Crop varieties with multiple herbicide-resistance traits are being rapidly adopted by growers and land managers to keep ahead of the weed resistance tsunami. This Special Issue of Plants comprises papers that describe the current status and future outlook of herbicide resistance research and development in weedy and domestic plants, with topics covering the full spectrum from resistance mechanisms to resistance management. The unifying framework for this Special issue is the challenge posed to all of the contributing authors: What are the (potential) implications for herbicide resistance management?

Author: Stephen B. Powles
Publisher: CRC Press
ISBN: 1420039083
Category : Science
Languages : en
Pages : 323

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Book Description
Written by experts from across the globe, Herbicide Resistance and World Grains evaluates the weed and herbicide management systems in major world grain crops such as soybean, maize, rice, and canola. The book examines the impact of transgenic crops and new technology on resistance management. It provides background information and offers practical

Author: Sava Vrbničanin
Publisher:
ISBN:
Category : Technology
Languages : en
Pages :

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Book Description
Unfortunately, herbicide resistance developed shortly after the introduction of the herbicides 2,4-D in 1957. According the herbicide resistance mechanisms, all processes can be grouped as follows: target-site resistance, non-target-site resistance, cross-resistance and multiple-resistance. Target-site resistance is generally due to a single or several mutations in the gene encoding the herbicide-target enzyme, which, in turn, decreases the affinity for herbicide binding to that enzyme. Non-target-site resistance is caused by mechanisms that reduce the amount of herbicidal active compound before it can attack the plant through the reduced absorption or altered translocation, increased herbicide sequestration or enhanced herbicide metabolism. Cross-resistance means that a single-resistance mechanism causes resistance to several herbicides with some mode of action. Multiple-resistance is a situation where two or more resistance mechanisms are present within the same plant, often due to sequential selection by herbicides with different modes of action. Currently, herbicide resistance has been reported in 478 weed biotypes (252 weed species) in 67 countries. Many of those biotypes are resistant to acetolactate synthase (ALS) inhibitors, PS II inhibitors, ACC-ase inhibitors and EPSPS inhibitors. Strategy for herbicide-resistance weed management must involve all the available preventive, cultural, mechanical and chemical measures for effective, safe and cost-effective weed control.

Author: Rafael Munhoz Pedroso
Publisher:
ISBN: 9781339824154
Category :
Languages : en
Pages :

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Book Description
Cyperus difformis and Schoenoplectus mucronatus are major weeds of paddy rice in California, where they evolved resistance to the acetolactate synthase (ALS)-inhibiting herbicide bensulfuron-methyl in the 1990's. More recently, recurrent applications of propanil (3,4-dichloropropionanilide) led to resistance to this important photosystem II (PSII)-inhibitor in a number of C. difformis and S. mucronatus populations. These populations were also resistant (R) to ALS-inhibitors. The objectives of this work were (a) to elucidate the mechanism of resistance to propanil in newly-obtained C. difformis and S. mucronatus biotypes, and (b) to uncover patterns of multiple herbicide resistance for the design of alternative chemical control options. Whole-plant, dose-response studies under controlled conditions showed at least a 14-fold increase in the level of propanil resistance in propanil-R C. difformis and S. mucronatus (Cd-PR and Sm-PR, respectively) biotypes relative to PSII-susceptible (S) cohorts. Interestingly, propanil-R biotypes were also resistant to the PSII-inhibitors diuron, metribuzin, and bromoxynil, but had greater susceptibility to the PSII-inhibitor bentazon compared to S biotypes. Treatments with the aryl acylamidase (AAA)-inhibitor carbaryl resulted in greater propanil phytotoxicity in S compared to R biotypes. These results suggest that, unlike propanil resistance in grasses, enhanced propanil metabolism by AAA is not the mechanism of resistance in C. difformis and S. mucronatus, which could be conferred by an altered target-site instead. The chloroplast psbA gene, which encodes the D1 protein (i.e. propanil's target-site) was amplified and sequenced in both R and S C. difformis and S. mucronatus biotypes. psbA DNA and cDNA sequence alignment identified an alteration at codon 655 in both Cd-PR and Sm-PR biotypes, which was altered from guanine in S to adenine in propanil-R biotypes. This alteration leads to a modification from valine (S) to the more bulky amino acid isoleucine (Val219Ile) in Cd-PR and Sm-PR that is expected to affect the binding affinity of PSII-inhibiting herbicides due to its location in the herbicide binding niche. These results are consistent with previous reports of weeds displaying a Val219Ile point mutation of the D1 protein, including diuron- and metribuzin-R populations of Poa annua. In order to uncover patterns of multiple herbicide-R in Cd-PR and Sm-PR, ALS activity assays were conducted following a modified, high-throughput assay protocol. The optimized protocol allowed for up to 3-fold increase in the number of assays performed per g of leaf fresh weight, which can help overcome the need for large seed amounts to generate sufficient plant material. ALS activity in Cd-PR and Sm-PR samples was less affected by bensulfuron-methyl than S cohorts, indicating that ALS inhibitor resistance likely stems from an altered target-site. Protein content (mg protein g−1 tissue), however, did not differ between R and S biotypes within each species. These results indicate that Cd-PR and Sm-PR do not have an overexpressed production of ALS enzymes, and therefore, suggest that ALS-inhibitor resistance in these biotypes could be conferred by amino acid exchanges in the ALS gene. However, specific target-site amino acid alterations have yet to be determined in the R biotypes used in this study. Lastly, the efficacy of thiobencarb for Cd-PR and Sm-PR control was ascertained to provide an alternative chemical control measure. Lack of cross-resistance to thiobencarb was observed as it provided satisfactory control of both R and S C. difformis biotypes, indicating this herbicide can be used in resistance management programs. In conclusion, this is the first report of C. difformis and S. mucronatus biotypes (single-seed descents) displaying resistance to both ALS- and PSII-inhibiting herbicides, as well as the first report of target site resistance to propanil in higher plants, as opposed to multiple reports of non-target site resistance. Besides endowing resistance to propanil, a novel attribute arising from a Val219Ile modification at the PS II D1 protein was also demonstrated, e.g. increased susceptibility to bentazon in both propanil-R C. difformis and S. mucronatus. As an herbicide used in many rice-growing regions worldwide, bentazon could be used as an effective option for control of propanil-R plants. Given that bentazon use is prohibited in California due to groundwater contamination issues in the 1990's, thiobencarb applications in post-emergence could provide satisfactory controls of multiple herbicide-R C. difformis and S. mucronatus in California rice production systems. From a weed management standpoint, the identification of two distinct target site-based mechanisms in biotypes of both weed species suggests that cross-resistance to herbicidal modes of action other than ALS or PSII inhibition is unlikely. The lack of cross-resistance to thiobencarb, a lipid synthesis-inhibiting herbicide in Cd-PR agrees with this finding. Therefore, other rice herbicides with different modes of action may also be useful tools for managing multiple herbicide-resistant C. difformis and S. mucronatus in California.

Author: Adam Jalaludin
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Herbicides are important tools in agriculture. They allow for a simple and effective method of weed control for growers in order to meet the global food demand. Unfortunately, intensive herbicide usage with diminishing diversity of weed control methods has resulted in weeds evolving resistance to herbicides. Herbicide resistance is now a major issue and challenge for growers globally. One of the problematic weed species, especially in the tropical and warm climate regions is Eleusine indica. Eleusine indica is a pernicious weed that is prone to evolve resistance to herbicides. Currently, global incidences of evolved resistance in E. indica include eight different herbicide sites of action, including glufosinate. Working with a glufosinate-resistant E. indica population from Malaysia, the resistance profile was further characterised and assessed for multiple resistance. Glufosinate resistance was confirmed in the E. indica population, with the GR50 (rate required to reduce the growth by 50%) and LD50 (rate required to kill 50% of the population) R/S ratios being 5- and 14-fold, respectively. More importantly, multiple resistance was observed, with the selected glufosinate-resistant subpopulation (R*) exhibiting a very high level of glyphosate resistance. The GR50 and LD50 R/S ratios obtained were 12- and 144-fold, respectively for glyphosate. This population had also evolved resistance to paraquat, albeit at a low level (GR50 and LD50 R/S ratios 2 to 3-fold, respectively). This species is the first to be reported to have evolved resistance to all three non-selective herbicides. Additionally, resistance to several ACCase-inhibiting herbicides, namely fluazifop-p-butyl, haloxyfop-p-methyl and butroxydim, was caused by a Trp-2027-Cys substitution in the ACCase protein sequence. In order to investigate the glufosinate resistance mechanism(s) in the R* population, activity of glutamine synthetase (GS) (the target -site of glufosinate) was compared in the S and R* populations. No difference in enzyme sensit ivity towards glufosinate was observed. Specific GS activity was also similar between S and R*. Differences in foliar uptake and translocation of [14C]-glufosinate were not significant between the two populations. HPLC analysis of glufosinate metabolism did not detect any metabolites in S or R* plants. Consequently, the resistance mechanism to glufosinate is not due to an insensitive target-site, target-site over production, differential glufosinate uptake and translocation, nor enhanced glufosinate metabolism, and remains to be determined. Sequencing of the glyphosate target gene, EPSPS, in the highly glyphosate resistant E. indica population revealed that a double mutation in the EPSPS gene, i.e. Thr-102-Ile and Pro-106-Ser (TIPS), was responsible for the high level glyphosate resistance. Importantly, this double mutation is similar to the first commercialised transgenic, glyphosate-tolerant EPSPS in maize, but has never been reported to occur naturally. Dose-response experiments showed that the naturally evolved TIPS mutants are 180-fold (LD50 based) more resistant to glyphosate than the wild type (WT) E. indica plants, and 32-fold more resistant than the Pro-106-Ser (P106S) (LD50 based) mutants. EPSPS inhibition assays also revealed similar results, with the TIPS EPSPS enzyme activity showing very high glyphosate resistance relative to wild type (WT) EPSPS (2600-fold) and P106S EPSPS (600-fold). Interestingly, the highly resistant TIPS mutant exhibited a resistance cost in terms of vegetative growth and seed production, while no resistance cost was observed for plants with the P106S mutation. Plants with the TIPS mutation had a higher basal shikimic acid (the substrate for EPSPS) level and lower tryptophan (a downstream product) levels than WT and P106S plants. The evolution of the TIPS double mutation is likely a sequential event, with the P106S mutation being selected first, followed by the T102I mutation, creating the highly glyphosate resistant TIPS EPSPS.

Author: Stephen B. Powles
Publisher: CRC Press
ISBN:
Category : Nature
Languages : en
Pages : 376

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Book Description
The late 1980s saw an explosion in the amount and diversity of herbicide resistance, posing a threat to crop production in many countries. The rapid escalation in herbicide resistance worldwide and in the understanding of resistance at the population, biochemical, and molecular level is the focus of this timely book. Leading researchers from North America, Australia, and Western Europe present lucid reviews that consider the population dynamics and genetics, biochemistry, and agro-ecology of resistance. Resistance to various herbicides is discussed in detail, as well as the mechanisms responsible for cross resistance and multiple resistance. This reference is invaluable to those interested in evolution and the ability of species to overcome severe environmental stress.

Author: Stephen O. Duke
Publisher: CRC Press
ISBN: 1351081640
Category : Science
Languages : en
Pages : 436

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Book Description
Edited by a recognized leader in the field, Herbicide-Resistant Crops is the first book to cover all of the issues related to the controversial topic of herbicide-resistant crops. It provides extensive discussions of the modern biotechnological methods that have been used to develop such crops, and reviews the implications - both positive and negative - of developing crops that are resistant to herbicides. The creation and anticipated applications of specific herbicide-resistant crops are also discussed. In addition, the book covers the potential impact of herbicide-resistant crops on weed management practices and the environment, and presents issues related to the regulation and economics of these crops. The editor has brought together a diverse group of professionals, representing the several distinct areas impacted by the new technology of herbicide-resistant crops. The wide range of viewpoints presented in this book creates a balanced and complete survey, providing a notable contribution to the literature.