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Review: Confirmation of Resistance to Herbicides and Evaluation of Resistance Levels

Published online by Cambridge University Press:  20 January 2017

Nilda R. Burgos*
Affiliation:
Department of Crop, Soil, and Environmental Sciences, University of Arkansas, Fayetteville, AR 72704
Patrick J. Tranel
Affiliation:
Department of Crop Sciences, University of Illinois, Urbana, IL 61801
Jens C. Streibig
Affiliation:
Department of Agriculture and Ecology, The University of Copenhagen, Taastrup 2630, Denmark
Vince M. Davis
Affiliation:
Department of Agronomy, University of Wisconsin-Madison, WI 53706
Dale Shaner
Affiliation:
USDA-ARS, Fort Collins, CO 80526
Jason K. Norsworthy
Affiliation:
Department of Crop, Soil, and Environmental Sciences, University of Arkansas, Fayetteville, AR 72704
Christian Ritz
Affiliation:
Department of Basic Science and Environment, University of Copenhagen, Frederiksberg C, Denmark 1871
*
Corresponding author's E-mail: nburgos@uark.edu
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Abstract

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As cases of resistance to herbicides escalate worldwide, there is increasing demand from growers to test for weed resistance and learn how to manage it. Scientists have developed resistance-testing protocols for numerous herbicides and weed species. Growers need immediate answers and scientists are faced with the daunting task of testing an increasingly large number of samples across a variety of species and herbicides. Quick tests have been, and continue to be, developed to address this need, although classical tests are still the norm. Newer methods involve molecular techniques. Whereas the classical whole-plant assay tests for resistance regardless of the mechanism, many quick tests are limited by specificity to an herbicide, mode of action, or mechanism of resistance. Advancing knowledge in weed biology and genomics allows for refinements in sampling and testing protocols. Thus, approaches in resistance testing continue to diversify, which can confound the less experienced. We aim to help weed science practitioners resolve questions pertaining to the testing of herbicide resistance, starting with field surveys and sampling methods, herbicide screening methods, data analysis, and, finally, interpretation. More specifically, this article discusses approaches for sampling plants for resistance confirmation assays, provides brief overviews on the biological and statistical basis for designing and analyzing dose–response tests, and discusses alternative procedures for rapid resistance confirmation, including molecular-based assays. Resistance confirmation procedures often need to be slightly modified to suit a specific situation; thus, the general requirements as well as pros and cons of quick assays and DNA-based assays are contrasted. Ultimately, weed resistance testing research, as well as resistance management decisions arising from research, needs to be practical, feasible, and grounded in science-based methods.

Type
Review
Creative Commons
Creative Common License - CCCreative Common License - BYCreative Common License - NCCreative Common License - SA
This is an Open Access article, distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike licence (http://creativecommons.org/licenses/by-nc-sa/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the same Creative Commons license is included and the original work is properly cited.
Copyright
Copyright © Weed Science Society of America

References

Literature Cited

Abdallah, I., Fischer, A. J., Elmore, C. L., Saltveit, M. E., and Zaki, M. 2006. Mechanism of resistance to quinclorac in smooth crabgrass (Digitaria ischaemum). Pestic. Biochem. Physiol. 84: 3848.Google Scholar
Ahrens, W. H., Arntzen, C. J., and Stoller, E. W. 1981. Chlorophyll fluorescence assay for determination of triazine resistance. Weed Sci. 29: 316322.Google Scholar
Avila, W., Bolaños, A., and Valverde, B. E. 2007. Characterization of the cross-resistance mechanism to herbicides inhibiting acetyl coenzyme-A carboxylase in itchgrass (Rottboelia cochinchinensis) biotypes from Bolivia. Crop Prot. 26: 342348.Google Scholar
Baerson, S. R., Rodriguez, D. J., Tran, M., Feng, Y., Biest, N. A., and Dill, G. R. 2002. Glyphosate-resistant goosegrass. Identification of a mutation in the target enzyme 5-enolypyruvylshikimate-3-phosphate synthase. Plant Physiol. 129: 12651275.Google Scholar
Ballot, R., Deschomets, G., and Gauvrit, C. 2009. A quick test for glyphosate resistance in ryegrass. 13th Int. Colloquium on Weed Biol. pp. 18.Google Scholar
Baumgartner, J. R., Al-Khatib, K., and Currie, R. S. 1999. Survey of common sunflower (Helianthus annuus) resistance to imazethapyr and chlorimuron in northeast Kansas. Weed Technol. 13: 510514.Google Scholar
Becerril, J. M. and Duke, S. O. 1989. Protoporphyrin IX content correlates with activity of photobleaching herbicides. Plant Physiol. 90: 11751181.Google Scholar
Beckie, H. J., Heap, I. M., Smeda, R. J., and Hall, L. M. 2000. Screening for herbicide resistance in weeds. Weed Technol. 14: 428445.Google Scholar
Beckie, H. J., Thomas, A. G., and Légère, A. 1999. Nature, occurrence, and cost of herbicide-resistant green foxtail (Setaria viridis) across Saskatchewan ecoregions. Weed Technol. 13: 626631.Google Scholar
Beckie, H. J., Thomas, A. G., and Stevenson, F. C. 2001. Survey of herbicide-resistant wild oat (Avena fatua) in two townships in Saskatchewan. Can. J. Plant Sci. 82: 463471.Google Scholar
Boudec, P., Rodgers, M., Dumas, F., Sailland, A., and Bourdon, H. 2001. Mutated hydroxyphenylpyruvate dioxygenase, DNA sequence and isolation of plants which contain such a gene and which are tolerant to herbicides. U.S. patent 6,245,968.Google Scholar
Bourgeois, L., Kenkel, N. C., and Morrison, I. N. 1997a. Characterization of cross-resistance patterns in acetyl-CoA carboxylase inhibitor resistant wild oat (Avena fatua). Weed Sci. 45: 750755.Google Scholar
Bourgeois, L. and Morrison, I. N. 1997a. Mapping risk areas for resistance to ACCase inhibitor herbicides in Manitoba. Can. J. Plant Sci. 77: 173179.Google Scholar
Bourgeois, L. and Morrison, I. N. 1997b. A survey of ACCase inhibitor resistant wild oat in a high risk township in Manitoba. Can. J. Plant Sci. 77: 703708.Google Scholar
Bourgeois, L., Morrison, I. N., and Kelner, D. 1997b. Field and producer survey of ACCase resistant wild oat in Manitoba. Can. J. Plant Sci. 77: 709715.Google Scholar
Boutsalis, P. 2001. Syngenta quick-test: A rapid whole-plant test for herbicide resistance. Weed Technol. 15: 257263.Google Scholar
Breccia, G., Vega, T., Nestares, G., Mayor, M. L., Zorzoli, R., and Picardi, L. 2011. Rapid test for detection of imidazolinone resistance in sunflower (Helianthus annuus L.). Plant Breed. 130: 109113.Google Scholar
Burgos, N. R., Culpepper, S., Dotray, P., Kendig, J. A., Wilcut, J., and Nichols, R. 2006. Managing herbicide resistance in cotton cropping systems. Cotton Inc. Tech. Bull. for the southern US. http://www.cottoninc.com/fiber/AgriculturalDisciplines/Weed-Management/Herbicide-Resistance-Cotton-Cropping-Systems/Managing-Herbicide-Resistance.pdf. Accessed: July 30, 2012.Google Scholar
Burgos, N. R., Kuk, Y. I., and Talbert, R. E. 2001. Amaranthus palmeri resistance and differential tolerance of A. palmeri and A. hybridus to ALS inhibitor herbicides. Pest Manag. Sci. 57: 449457.Google Scholar
Burke, I. C., Thomas, W. E., Burton, J. D., Spears, J. F., and Wilcut, J. W. 2006. A seedling assay to screen aryloxyphenoxypropionic acid and cyclohexanedione resistance in johnsongrass (Sorghum halepense). Weed Technol. 20: 950955.Google Scholar
Busch, M., Fischer, K., Laber, B., and Sailland, A. 2011. New mutated hydroxyphenylpyruvate dioxygenase, DNA sequence and isolation of plants which are tolerant to HPPD inhibitor herbicides. U.S. patent Application 20110039706.Google Scholar
Busi, R. and Powles, S. 2009. Evolution of glyphosate resistance in a Lolium rigidum population by glyphosate selection at sublethal doses. Heredity 103: 318325.Google Scholar
Claude, J.-P., Didier, A., Favier, P., and Thalinger, P. P. 2004. Epidemiological study of blackgrass (Alopecurus myosoroides Huds.) herbicide resistance in cereal crops through the analysis of a European database. In: Proc. of the XII Colloque International sur la Biologie des Mauvaises Herbes, Paris., Pp.567574.Google Scholar
Collavo, A., Panozzo, S., Lucchesi, G., Scarabel, L., and Sattin, M. 2011. Characterization and management of Phalaris paradoxa resistant to ACCase-inhibitors. Crop Prot. 30: 293299.Google Scholar
Corbett, C. L. and Tardif, F. J. 2006. Detection of resistance to acetolactate synthase inhibitors in weeds with emphasis on DNA-based techniques: a review. Pest Manag. Sci. 62: 584597.Google Scholar
Corbett, C. L. and Tardif, F. J. 2008. Detection of resistance to acetohydroxyacid synthase inhibitors in Amaranthus sp. using DNA polymorphisms. Pestic. Biochem. Physiol. 92: 4855.Google Scholar
Cromartie, T. H. and Polge, N. D. 2000. An improved assay for shikimic acid and its use as a monitor for the activity of sulfosate. Proc. Weed Sci. Soc. Am. 40: 291.Google Scholar
Cruz-Hipolito, H., Dominguez-Valenzuela, J. A., Osuna, M. D., and de Prado, R. 2012. Resistance mechanism to acetyl coenzyme A carboxylase inhibiting herbicides in Phalaris paradoxa collected in Mexican wheat fields. Plant Soil. 355: 121130.Google Scholar
Cruz-Hipolito, H., Osuna, M. D., Dominguez-Valenzuela, J. A., Espinoza, N., and de Prado, R. 2011. Mechanism of resistance to ACCase-inhibiting herbicides in wild oat (Avena fatua) from Latin America. J. Agric. Food Chem. 59: 72617267.Google Scholar
Cutulle, M. A., McElroy, J. S., Millwood, R. W., Sorochan, J. C., and Neal Stewart, C. Jr. 2009. Selection of bioassay method influences detection of annual bluegrass resistance to mitotic-inhibiting herbicides. Crop Sci. 49: 10881095.Google Scholar
Dauer, J. T., Mortensen, D. A., and Humston, R. 2006. Controlled experiments to predict horseweed (Conyza canadensis) dispersal distances. Weed Sci. 54: 484489.Google Scholar
Davis, V. M., Gibson, K. D., and Johnson, W. G. 2008. A field survey to determine distribution and frequency of glyphosate-resistant horseweed (Conyza canadensis) in Indiana. Weed Technol. 22: 331338.Google Scholar
Davis, V. M., Gibson, K. D., Mock, V. A., and Johnson, W. G. 2009. In-field and soil-related factors that affect the presence and prediction of glyphosate-resistant horseweed (Conyza canadensis) populations collected from Indiana soybean fields. Weed Sci. 57: 281289.Google Scholar
Davis, V. M., Kruger, G. R., Hallett, S. G., Tranel, P. J., and Johnson, W. G. 2010. Heritability of glyphosate resistance in Indiana horseweed (Conyza canadensis) populations. Weed Sci. 58: 3038.Google Scholar
Délye, C., Calmès, É., and Matéjicek, A. 2002a. SNP markers for black-grass (Alopecurus myosuroides Huds.) genotypes resistant to acetyl CoA-carboxylase inhibiting herbicides. Theor. Appl. Genet. 104: 11141120.Google Scholar
Délye, C., Pernin, F., and Michel, S. 2011. ‘Universal’ PCR assays detecting mutations in acetyl-coenzyme A carboxylase or acetolactate synthase that endow herbicide resistance in grass weeds. Weed Res. 51: 353362.Google Scholar
Délye, C., Wang, T., and Darmency, H. 2002b. An isoleucine substitution in chloroplastic acetyl-CoA carboxylase from green foxtail (Setaria viridis L. Beauv.) is responsible for resistance to the cyclohexanedione herbicide, sethoxydim. Planta 214: 421–227.Google Scholar
Dickson, J. W., Scott, R. C., Burgos, N. R., Salas, R. A., and Smith, K. L. 2011. Confirmation of glyphosate-resistant Italian ryegrass (Lolium perenne ssp. multiflorum) in Arkansas. Weed Technol. 25: 674679.Google Scholar
Falk, J. S., Al-Khatib, K., and Peterson, D. E. 2006. Rapid assay evaluation of plant response to protoporphyrinogen oxidase (Protox) –inhibiting herbicides. Weed Technol. 20: 104112.Google Scholar
Falk, J. S., Shoup, D. E., Al-Khatib, K., and Peterson, D. E. 2005. Survey of common waterhemp (Amaranthus rudis) response to protox- and ALS-inhibiting herbicides in northeast Kansas. Weed Technol. 19: 838846.Google Scholar
Fuerst, W. P., Nakatani, H. Y., Dodge, A. D., Penner, D., and Arntzen, C. J. 1985. Paraquat resistance in Conyza . Plant Physiol. 77: 984989.Google Scholar
Gaines, T. A., Zhang, W., Wang, D., Bukun, B., Chisholm, S. T., Shaner, D. L., Nissen, S. J., Patzoldt, W. L., Tranel, P. J., Culpepper, A. S., Grey, T. L., Webster, T. M., Vencill, W. K., Sammons, R. D., Jiang, J., Preston, C., Leach, J. E., and Westra, P. 2010. Gene amplification confers glyphosate resistance in Amaranthus palmeri . Proc. Natl. Acad. Sci. U. S. A. 107: 10291034.Google Scholar
Gerwick, B. C., Mireles, L. C., and Eilers, R. J. 1993. Rapid diagnosis of ALS/AHAS-resistant weeds. Weed Technol. 7: 519524.Google Scholar
Gherekhloo, J., Mohassel, M. H. R., Mahalati, M. N., Zand, E., Ghanbari, A., Osuna, M. D., and de Prado, R. 2011. Confirmed resistance to aryloxyphenoxypropionate herbicides in Phalaris minor populations in Iran. Weed Biol. Manag. 11: 2937.Google Scholar
Giancola, S., McKhann, H. I., Bérard, A., Camilleri, C., Durand, S., Libeau, P., Roux, F., Reboud, X., Gut, I. G., and Brunel, D. 2006. Utilization of the three high-throughput SNP genotyping methods, the GOOD assay, Amplifluor and TaqMan, in diploid and polyploid plants. Theor. Appl. Genet. 112: 11151124.Google Scholar
Gressel, J. and Segel, L. A. 1978. The paucity of plants evolving genetic resistance to herbicides: possible reasons and implications. J. Theor. Biol. 75: 349371.Google Scholar
Gressel, J. and Segel, L. A. 1990. Modelling the effectiveness of herbicide rotations and mixtures as strategies to delay or preclude resistance. Weed Technol. 4: 186198.Google Scholar
Gronwald, J. W. 1994. Resistance to photosystem II inhibiting herbicides. Pages 2760 in Powles, S. B. and Holtum, J.A.M., eds. Herbicide Resistance in Plants—Biology and Biochemistry. Boca Raton, FL: CRC Press.Google Scholar
Gui-qi, W., Cui, H. I., Zhang, H., Zhang, Y., Xue, L., Li, X., and Cui-Qin, F. 2011. Tribenuron-methyl-resistant shepherd's purse (Capsella bursa-pastoris L. Medik) in Hebei province of China. Agric. Sci. China 10: 12411245.Google Scholar
Guttieri, M. J., Eberlein, C. V., Mallory-Smith, C. A., Thill, D. C., and Hoffman, D. L. 1992. DNA sequence variation in domain A of the acetolactate synthase genes of herbicide-resistant and -susceptible weed biotypes. Weed Sci. 40: 670676.Google Scholar
Hamouzová, K., Soukup, J., Jursí, K. M., Hamouz, P., Venclová, V., and Tómová, P. 2011. Cross-resistance to three frequently used sulfonylurea herbicides in populations of Apera spica-venti from the Czech Republic. Weed Res. 51: 113122.Google Scholar
Han, H., Yu, Q., Purba, E., Li, M., Walsh, M., Friesen, S., and Powles, S. B. 2012. A novel amino acid substitution Ala-122-Tyr in ALS confers high-level and broad resistance across ALS-inhibiting herbicides. Pest Manag Sci. 68: 11641170.Google Scholar
Hanson, B., Shrestha, A., and Shaner, D. 2009. Distribution of glyphosate-resistant horseweed (Conyza canadensis) and relationship to cropping systems in the Central Valley of California. Weed Sci. 57: 4853.Google Scholar
Hausman, N. E., Singh, S., Tranel, P. J., Riechers, D. E., Kaundun, S. S., Polge, N. D., Thomas, D. A., and Hager, A. G. 2011. Resistance to HPPD-inhibiting herbicides in a population of waterhemp (Amaranthus tuberculatus) from Illinois, United States. Pest Manag. Sci. 67: 258261.Google Scholar
Heap, I. 2012. The International Survey of Herbicide-Resistant Weeds. Available at www.weedscience.com. Accessed July 15, 2012.Google Scholar
Hensley, J. R. 1981. A method for identification of triazine-resistant and -susceptible biotypes of several weeds. Weed. Sci. 29: 7072.Google Scholar
[HRAC] Herbicide Resistance Action Committee. 2012. Herbicide Resistance Testing Facilities. http://www.hracglobal.com/Publications/. Accessed: July 30, 2012.Google Scholar
Huan, Z., Zhang, H., Hou, Z., Zhang, S., Zhang, Y., Liu, W., Bi, Y., and Wang, J. 2011. Resistance level and metabolism of barnyardgrass (Echinochloa crus-galli L. Beauv.) populations to quizalofop-P-ethyl in Heilongjiang province, China. Agric. Sci. China 10: 19141922.Google Scholar
Kaloumenos, N. S., Adamouli, V. N., Dordas, C. A., and Eleftherohorinos, I. G. 2011. Corn poppy (Papaver rhoeas) cross-resistance to ALS-inhibiting herbicides. Pest Manag. Sci. 67: 574585.Google Scholar
Kaloumenos, N. S. and Eleftherohorinos, I. G. 2009. Identification of a johnsongrass (Sorghum halepense) biotype resistant to ACCase-inhibiting herbicides in Northern Greece. Weed Technol. 23: 470476.Google Scholar
Kaundun, S. S. 2010. An aspartate to glycine change in the carboxyl transferase domain of acetyl CoA carboxylase and non-target-site mechanism(s) confer resistance to ACCase inhibitor herbicides in a Lolium multiflorum population. Pest Manag. Sci. 66: 12491256.Google Scholar
Kaundun, S. S., Cleere, S. M., Stanger, C. P., Burbidge, J. M., and Windass, J. D. 2006. Real-time quantitative PCR assays for quantification of L1781 ACCase inhibitor resistance allele in leaf and seed pools of Lolium populations. Pest Manag. Sci. 62: 10821091.Google Scholar
Kaundun, S. S., Dale, R. P., Zelaya, I. A., Dinelli, G., Marotti, I., McIndoe, E., and Cairns, A. 2011a. A novel P106L mutation in EPSPS and an unknown mechanism(s) act additively to confer resistance to glyphosate in a South African Lolium rigidum population. J. Agric. Food Chem. 59: 32273233.Google Scholar
Kaundun, S. S., Hutchings, S-J., Dale, R. P., Bailly, G. C., and Glanfield, P. 2011b. Syngenta ‘RISQ’ test: a novel in-season method for detecting resistance to post-emergence ACCase and ALS inhibitor herbicides in grass weeds. Weed Res. 51: 284293.Google Scholar
Kaundun, S. S. and Windass, J. D. 2006. Derived cleaved amplified polymorphic sequence, a simple method to detect a key point mutation conferring acetyl CoA carboxylase inhibitor resistance in grass weeds. Weed Res. 46: 3439.Google Scholar
Koger, C. H., Shaner, D. L., Henry, W. B., Nadler-Hassar, T., Thomas, W. E. T., and Wilcut, J. W. 2005. Assessment of two nondestructive assays for detecting glyphosate resistance in horseweed (Conyza canadensis). Weed Sci. 53: 438445.Google Scholar
Korres, N. E., Froud-Williams, R. J., and Moss, S. R. 2003. Chlorophyll fluorescence technique as a rapid diagnostic test of the effects of the photosynthetic inhibitor chlorotoluron on two winter wheat cultivars. Ann. Appl. Biol. 143: 5356.Google Scholar
Kuk, Y. I. and Burgos, N. R. 2007. Cross-resistance profile of mesosulfuron-methyl–resistant Italian ryegrass in the southern United States. Pest Manag. Sci. 63: 349357.Google Scholar
Kuk, Y. I., Jung, H. I., Kwon, O. D., Lee, D. J., Burgos, N. R., and Guh, J. A. 2003. Rapid diagnosis of resistance to sulfonylurea herbicides in monochoria (Monochoria vaginalis). Weed Sci. 51: 305311.Google Scholar
Kuk, Y. I., Wu, J., Derr, J. F., and Hatzios, K. K. 1999. Mechanism of fenoxaprop resistance in an accession of smooth crabgrass (Digitaria ischaemum). Pestic. Biochem. Physiol. 64: 112123.Google Scholar
Kwok, S., Kellogg, D. E., McKinney, N., Spasic, D., Goda, L., Levenson, C., and Sninsky, J. J. 1990. Effects of primer–template mismatches on the polymerase chain reaction: human immunodeficiency virus type 1 model studies. Nucleic Acids Res. 18: 9991005.Google Scholar
Lamego, F. P., Charlson, D., Delatorre, C. A., Burgos, N. R., and Vidal, R. A. 2009. Molecular basis of resistance to ALS-inhibitor herbicides in greater beggarticks. Weed Sci. 57: 474481.Google Scholar
Laplante, J., Rajcan, I., and Tardif, F. J. 2009. Multiple allelic forms of acetohydroxyacid synthase are responsible for herbicide resistance in Setaria viridis . Theor. Appl. Genet. 119: 577585.Google Scholar
Lee, R. M., Hager, A. G., and Tranel, P. J. 2008. Prevalence of a novel resistance mechanism to PPO-inhibiting herbicides in waterhemp. Weed Sci. 56: 371375.Google Scholar
Légère, A., Beckie, H. J., Stevenson, F. C., and Thomas, A. G. 2000. Survey of management practices affecting the occurrence of wild oat (Avena fatua) resistance to acetyl-CoA carboxylase inhibitors. Weed Technol. 14: 366376.Google Scholar
Legleiter, T. R. and Bradley, K. W. 2008. Glyphosate and multiple herbicide resistance in common waterhemp (Amaranthus rudis) populations from Missouri. Weed Sci. 56: 582587.Google Scholar
Lehoczki, E., Laskay, G., Gaal, I., and Szigeti, Z. 1992. Mode of action of paraquat in leaves of paraquat-resistant Conyza canadensis (L.) Conq. Plant Cell Environ. 15: 531539.Google Scholar
Letouzé, A. and Gasquez, J. 2000. A pollen test to detect ACCase target-site resistance within Alopecurus myosuroides populations. Weed Res. 40: 151162.Google Scholar
Llewellyn, R. S. and Powles, S. B. 2001. High levels of herbicide resistance in rigid ryegrass (Lolium rigidum) in the wheat belt of Western Australia. Weed Technol. 15: 242248.Google Scholar
Maneechote, C., Preston, C., and Powles, S. B. 1997. A diclofop-methyl-resistant Avena sterilis biotype with a herbicide-resistant acetyl-coenzyme A carboxylase and enhanced metabolism of diclofop-methyl. Pestic. Sci. 49: 105114.Google Scholar
Maneechote, C., Samanwong, S., Zhang, X. Q., and Powles, S. B. 2005. Resistance to ACCase-inhibiting herbicides in sprangletop (Leptochloa chinensis). Weed Sci. 53: 290295.Google Scholar
Marshall, R. and Moss, S. R. 2008. Characterization and molecular basis of ALS inhibitor resistance in the grass weed Alopecurus myosuroides . Weed Res. 48: 439447.Google Scholar
McCullagh, P. and Nelder, J. A. 1989. Generalized linear models. 2nd ed New York. Chapman and Hall. 511.Google Scholar
McMullan, G. M. and Green, J. M. 2011. Identification of a tall waterhemp (Amaranthus tuberculatus) biotype resistant to HPPD-inhibiting herbicides, atrazine, and thifensulfuron in Iowa. Weed Technol. 25: 514518.Google Scholar
Mechant, E., De Marez, T., Aper, J., and Bulcke, R. 2010. Chlorophyll fluorescence protocol for quick detection of triazinone-resistant Chenopodium album L. Commun. Appl. Biol. Sci. 76: 8390.Google Scholar
Mennan, H., Streibig, J. C., Ngouajio, M., and Kaya, E. 2011. Tolerance of two Bifora radians Bieb populations to ALS inhibitors in winter wheat. Pest Manag. Sci. 68: 116122.Google Scholar
Merotto, A. Jr., Jasieniuk, M., Osuna, M. D., Vidotto, F., Ferrero, A., and Fischer, A. J. 2009. Cross-resistance to herbicides of five ALS-inhibiting groups and sequencing of the ALS gene in Cyperus difformis L. J. Agric. Food Chem. 57: 13891398.Google Scholar
Michel, A., Arias, R. S., Scheffler, B. E., Duke, S. O., Netherland, M., and Dayan, F. E. 2004. Somatic mutation-mediated evolution of herbicide resistance in the nonindigenous invasive plant hydrilla (Hydrilla verticillata). Mol. Ecol. 13: 32293237.Google Scholar
Moss, S. 1999. Detecting herbicide resistance: guidelines for conducting diagnostic tests and interpreting results. Herbicide Resistance Action Committee (HRAC). http://www.hracglobal.com/Publications/DetectingHerbicideResistance/. Accessed: December 10, 2011.Google Scholar
Moss, S. R., Cocker, K. M., Brown, A. C., Hall, L., and Field, L. M. 2003. Characterization of target site resistance to ACCase-inhibiting herbicides in the weed Alopecurus myosuroides (black-grass). Pest Manag. Sci. 59: 190201.Google Scholar
Muenscher, W. C. 1935. Weeds. New York: MacMillan. Pp 4950.Google Scholar
Nandula, V. K., Poston, D. H., Eubank, T. W., Koger, C. H., and Reddy, K. N. 2007. Differential response to glyphosate in Italian ryegrass (Lolium multiflorum) populations from Mississippi. Weed Technol. 21: 477482.Google Scholar
Neff, M. M., Neff, J. D., Chory, J., and Pepper, A. E. 1998. dCAPS, a simple technique for the genetic analysis of single nucleotide polymorphisms: experimental applications in Arabidopsis thaliana genetics. Plant J. 14: 387392.Google Scholar
Neff, M. M., Turk, E., and Kalishman, M. 2002. Web-based primer design for singly nucleotide polymorphism analysis. Trends Genet. 18: 613615.Google Scholar
Neve, P. and Powles, S. 2005a. High survival frequencies at low herbicide use rates in populations of Lolium rigidum result in rapid evolution of herbicide resistance. Heredity 95: 485492.Google Scholar
Neve, P. and Powles, S. 2005b. Recurrent selection with reduced herbicide rates results in rapid evolution of herbicide resistance in Lolium rigidum . Theor. Appl. Genet. 10: 11541166.Google Scholar
Norsworthy, J. K. 2012. Repeated sublethal rates of glyphosate lead to decreased sensitivity in Palmer amaranth . Crop Manag. DOI:10.1094/CM-2012-0403-01-RS.Google Scholar
Norsworthy, J. K., Griffith, G. M., Scott, R. C., Smith, K. L., and Oliver, L. R. 2008. Confirmation and control of glyphosate-resistant Palmer amaranth (Amaranthus palmeri) in Arkansas. Weed Technol. 22: 108113.Google Scholar
Norsworthy, J. K., Talbert, R. E., and Hoagland, R. E. 1999. Chlorophyll fluorescence evaluation of agrochemical interactions with propanil on propanil-resistant barnyardgrass (Echinochloa crus-galli). Weed Sci. 47: 1319.Google Scholar
Owen, M. J., Goggin, D. E., and Powles, S. B. 2012. Non-target-site-based resistance to ALS-inhibiting herbicides in six Bromus rigidus populations from Western Australian cropping fields. Pest Manag. Sci. 68: 10771082.Google Scholar
Owen, M. J. and Powles, S. B. 2009. Distribution and frequency of herbicide-resistant wild oat (Avena spp.) across Western Australian grain belt. Crop Pasture Sci. 60: 2531.Google Scholar
Patzoldt, W. L., Hager, A. G., McCormick, J. S., and Tranel, P. J. 2006. A codon deletion confers resistance to herbicides inhibiting protoporphyrinogen oxidase. Proc. Natl. Acad. Sci. U. S. A. 103: 1232912334.Google Scholar
Patzoldt, W. L., Tranel, P. J., and Hager, A. G. 2005. A waterhemp (Amaranthus tuberculatus) biotype with multiple resistance across three herbicide sites of action. Weed Sci. 53: 3036.Google Scholar
Pettersson, M., Bylund, M., and Alderborn, A. 2003. Molecular haplotype determination using allele-specific PCR and pyrosequencing technology. Genomics 82: 390396.Google Scholar
Powles, S. B. and Yu, Q. 2010. Evolution in action: plants resistant to herbicides. Annu. Rev. Plant Biol. 61: 317347.Google Scholar
Rew, L. J. and Cussans, G. W. 1997. Horizontal movement of seeds following tine and plough cultivation: implications for spatial dynamics of weed infestations. Weed Res. 37: 247256.Google Scholar
Ritz, C. 2010. Toward a unified approach to dose–response modeling in ecotoxicology. Environ. Toxicol. Chem. 29: 220229.Google Scholar
Ritz, C., Cedergreen, N., Jensen, J. E., and Streibig, J. C. 2006. Relative potency in nonsimilar dose–response curves. Weed Sci. 54: 407412.Google Scholar
Ritz, C. and Streibig, J. C. 2009. Functional regression analysis of fluorescence curves. Biometrics 65: 609617.Google Scholar
Salas, R. A., Dayan, F. E., Pan, Z., Watson, S. B., Dickson, J. W., Scott, R. C., and Burgos, N. R. 2012. EPSPS gene amplification in glyphosate-resistant Italian ryegrass (Lolium perenne ssp. multiflorum) from Arkansas. Pest Manag. Sci. 68: 12231230.Google Scholar
Shaner, D. L., Nadler-Hassar, T., Henry, B., and Koger, C. 2005. A rapid in vivo shikimate accumulation assay with excised leaf discs. Weed Sci. 53: 769774.Google Scholar
Singh, B. J. and Shaner, D. L. 1998. Rapid determination of glyphosate injury to plants and identification of glyphosate-resistant plants. Weed Technol. 12: 527530.Google Scholar
Streibig, J. C., Walker, A., Blair, A. M., Anderson-Taylor, G., Eagle, D. J., Friedländer, H., Hacker, E., Iwanzik, W., Kudsk, P., Labhart, C., Luscombe, B. M., Madafiglio, G., Nel, P. C., Pestemer, W., Rahman, A., Retzlaff, G., Rola, J., Stefanovic, L., Straathof, H. J. M., and Thies, E. P. 1995. Variability of bioassays with metsulfuron-methyl in soil. Weed Res. 35: 215224.Google Scholar
Switzer, C. M. 1957. The existence of 2,4-D–resistant strains of wild carrot. Proc. Northeast. Weed Control Conf. 11: 315318.Google Scholar
Taylor, J. B., Loux, M. M., Harrison, S. K., and Regnier, E. 2002. Response of ALS-resistant common ragweed (Ambrosia artemisiifolia) and giant ragweed (Ambrosia trifida) to ALS-inhibiting and alternative herbicides. Weed Technol. 16: 815825.Google Scholar
Trainer, G. D., Loux, M. M., Harrision, S. K., and Regnier, E. 2005. Response of horseweed biotypes to foliar applications of cloransulam-methyl and glyphosate. Weed Technol. 19: 231236.Google Scholar
Tranel, P. J., Riggins, C. W., Bell, M. S., and Hager, A. G. 2011. Herbicide resistances in Amaranthus tuberculatus: a call for new options. J. Agric. Food Chem. 59: 58085812.Google Scholar
Tranel, P. J. and Wright, T. R. 2002. Resistance of weeds to ALS-inhibiting herbicides: what have we learned. Weed Sci. 50: 700712.Google Scholar
Tranel, P. J., Wright, T. R., and Heap, I. M. 2012. ALS mutations from herbicide-resistant weeds. http://www.weedscience.org. Accessed: July 18, 2012.Google Scholar
Trucco, F., Jeschke, M. R., Rayburn, A. L., and Tranel, P. J. 2005. Amaranthus hybridus can be pollinated frequently by A. tuberculatus under field conditions. Heredity 94: 6470.Google Scholar
Truelove, B., Davis, D. E., and Jones, L. R. 1974. A new method for detecting photosynthesis inhibitors. Weed. Sci. 22: 1517.Google Scholar
Tucker, K. P., Morgan, G. D., Senseman, S. A., Miller, T. D., and Bauman, P. A. 2006. Identification, distribution, and control of Italian ryegrass (Lolium multiflorum) ecotypes with varying levels of sensitivity to triasulfuron in Texas. Weed Technol. 20: 745750.Google Scholar
Walsh, M. J., Duane, R. D., and Powles, S. B. 2001. High frequency of chlorsulfuron-resistant wild radish (Raphanus raphanistrum L.) populations across the Western Australian wheatbelt. Weed Technol. 15: 199203.Google Scholar
Walsh, M. J., Owen, M. J., and Powles, S. B. 2007. Frequency and distribution of resistance in Raphanus raphanistrum population randomly collected across the Western Australian wheatbelt. Weed Res. 47: 542550.Google Scholar
Warwick, S. I., Xu, R., Sauder, C., and Beckie, H. J. 2008. Acetolactate synthase target-site mutations and single nucleotide polymorphism genotyping in ALS-resistant kochia (Kochia scoparia). Weed Sci. 56: 797806.Google Scholar
Weaver, S. E. 2001. The biology of Canadian weeds: Conyza canadensis . Can. J. Plant Sci. 81: 867875.Google Scholar
Whaley, C. M., Wilson, H. P., and Westwood, J. H. 2007. A new mutation in plant ALS confers resistance to five classes of ALS-inhibiting herbicides. Weed Sci. 55: 8390.Google Scholar
Wise, A. M., Grey, T. L., Prostko, E. P., Vencill, W. K., and Webster, T. M. 2009. Establishing the geographical distribution and level of acetolactate synthase resistance of Palmer amaranth (Amaranthus palmeri) accessions in Georgia. Weed Technol. 23: 214220.Google Scholar
Xu, X., Wang, G. Q., Chen, S. L., Fan, C. Q., and Li, B. H. 2010. Confirmation of flixweed (Descurainia sophia) resistance to tribenuron-methyl using three different assay methods. Weed Sci. 58: 5660.Google Scholar
Yu, Q., Han, H., Li, M., Purba, E., Walsh, M. J., and Powles, S. B. 2012. Resistance evaluation for herbicide resistance–endowing acetolactate synthase (ALS) gene mutations using Raphanus raphanistrum populations homozygous for specific ALS mutations. Weed Res. 52: 178186.Google Scholar
Yu, Q., Nelson, J. K., Zheng, M. Q., Jackson, M., and Powles, S. B. 2007. Molecular characterization of resistance to ALS-inhibiting herbicides in Hordeum leporinum biotypes. Pest Manag. Sci. 63: 918927.Google Scholar
Zheng, D., Kruger, G. R., Singh, S., Davis, V. M., Tranel, P. J., Weller, S. C., and Johnson, W. G. 2011. Cross-resistance of horseweed (Conyza canadensis) populations with three different ALS mutations. Pest Manag. Sci. 67: 14861492.Google Scholar
Zheng, D., Patzoldt, W. L., and Tranel, P. J. 2005. Association of the W574L ALS substitution with resistance to cloransulam and imazamox in common ragweed (Ambrosia artemisiifolia). Weed Sci. 53: 424430.Google Scholar