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Evolved resistance to acetolactate synthase–inhibiting herbicides in common sunflower (Helianthus annuus), giant ragweed (Ambrosia trifida), and shattercane (Sorghum bicolor) in Iowa

  • Ian A. Zelaya and Micheal D. K. Owen (a1)


Weed biotypes putatively resistant to acetolactate synthase (ALS)–inhibiting herbicides were reported by Iowa farmers from 1997 to 2001. Greenhouse studies confirmed cross-resistance to triazolopyrimidine sulfonanilide and sulfonylurea (SU) herbicides in giant ragweed from Scott County, IA (Werner Farm), which corresponded to resistance to susceptibility (R:S) GR50 (50% growth reduction) ratios of 21 and 28 to cloransulam and primisulfuron + prosulfuron, respectively. At the enzyme level, this represented a 49- and 20-fold I 50 (50% enzyme inhibition) increase. Cross-resistance to imidazolinone (IMI) and SU herbicides was also observed in common sunflower from Cherokee, IA. Compared with a susceptible biotype, the resistant common sunflower biotype demonstrated GR50 R:S ratios of 36 and 43 to imazethapyr and chlorimuron, respectively. Shattercane from Malvern, IA, was susceptible to nicosulfuron but was resistant to imazethapyr (GR50 R:S ratio = 29). The woolly cupgrass biotypes from Union County, IA (Pettit Farm and Travis Farm), were reportedly resistant but were identified susceptible to both IMI and SU herbicides. Using an in vivo ALS assay, extractable endogenous 2,3-diketone concentrations ranged from 25 to 71 nmol g−1 fresh weight for all species. Compared with susceptible biotypes, 2,3-diketone levels accumulated to at least twofold higher levels in treated resistant plants 120 h after herbicide application. Field history data suggested that resistance evolved independently in three environments where ALS-inhibiting herbicides represented an important component of the selection pressure.


Corresponding author

Corresponding author. Department of Agronomy, Iowa State University, Ames, IA 50011-1011;


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Al-Khatib, K., Baumgartner, J. R., Peterson, D. E., and Currie, R. S. 1998. Imazethapyr resistance in common sunflower (Helianthus annuus). Weed Sci 46:403407.
Al-Khatib, K., Peterson, D. E., and Regehr, D. L. 2000. Control of imazethapyr-resistant common sunflower (Helianthus annuus) in soybean (Glycine max) and corn (Zea mays). Weed Technol 14:133139.
Allen, J. R., Johnson, W. G., Smeda, R. J., Wiebold, W. J., and Massey, R. E. 2001. Management of acetolactate synthase (ALS)-resistant common sunflower (Helianthus annuus L.) in soybean (Glycine max). Weed Technol 15:571575.
Anderson, D. D., Nissen, S. J., Martin, A. R., and Roeth, F. W. 1998a. Mechanism of primisulfuron resistance in a shattercane (Sorghum bicolor) biotype. Weed Sci 46:158162.
Anderson, D. D., Roeth, F. W., and Martin, A. R. 1998b. Discovery of a primisulfuron-resistant shattercane (Sorghum bicolor) biotype. Weed Technol 12:7477.
Ballard, T. O., Foley, M. E., and Bauman, T. T. 1995. Absorption, translocation, and metabolism of imazethapyr in common ragweed (Ambrosia artemisiifolia) in giant ragweed (Ambrosia trifida). Weed Sci 43:572577.
Ballard, T. O., Foley, M. E., and Bauman, T. T. 1996. Response of common ragweed (Ambrosia artemisiifolia) and giant ragweed (Ambrosia trifida) to postemergence imazethapyr. Weed Sci 44:248251.
Bassett, I. J. and Crompton, C. W. 1982. The biology of Canadian weeds. 55. Ambrosia trifida L. Can. J. Plant Sci 62:10031010.
Baumgartner, J. R., Al-Khatib, K., and Currie, R. S. 1999. Cross-resistance of imazethapyr-resistant common sunflower (Helianthus annuus) to selected imidazoline, sulfonylurea, and triazolopyrimidine herbicides. Weed Technol 13:489493.
Buhler, D. D. and Hartzler, R. G. 2001. Emergence and persistence of seed of velvetleaf, common waterhemp, woolly cupgrass, and giant foxtail. Weed Sci 49:230235.
Durner, J. and Böger, P. 1991. New aspects on inhibition of plant acetolactate synthase by chlorsulfuron and imazaquin. Plant Physiol 95:11441149.
Franey, R. J. and Hart, S. E. 1999. Time of application of cloransulam for giant ragweed (Ambrosia trifida) control in soybean (Glycine max). Weed Technol 13:825828.
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.
Heap, I. 2003. The International Survey of Herbicide Resistant Weeds.
Hinz, J. R. R., Owen, M. D. K., and Barrett, M. 1997. Nicosulfuron, primisulfuron, and bentazon hydroxylation by corn (Zea mays), woolly cupgrass (Eriochloa villosa), and shattercane (Sorghum bicolor) cytochrome P-450. Weed Sci 45:474480.
Lee, C. D., Martin, A. R., Roeth, F. W., Johnson, B. E., and Lee, D. J. 1999. Comparison of ALS inhibitor resistance and allelic interactions in shattercane accessions. Weed Sci 47:275281.
Leif, J. W., Vollmer, J. L., Hartberg, T. J., and Ballard, T. O. 2000. Growth and response of common ragweed (Ambrosia artemisiifolia) ecotypes to imazethapyr. Weed Technol 14:150155.
Marshall, M. W., Al-Khatib, K., and Loughin, T. 2001. Gene flow, growth, and competitiveness of imazethapyr-resistant common sunflower. Weed Sci 49:1421.
Mickelson, J. A. and Harvey, R. G. 2000. Woolly cupgrass (Eriochloa villosa) management in corn (Zea mays) by sequential herbicide applications and cultivation. Weed Technol 14:502510.
Patzoldt, W. L. and Tranel, P. J. 2002. Molecular analysis of cloransulam resistance in a population of giant ragweed. Weed Sci 50:299305.
Patzoldt, W. L., Tranel, P. J., Alexander, A. L., and Schmitzer, P. R. 2001. A common ragweed population resistant to cloransulam-methyl. Weed Sci 49:485490.
Rabaey, T. L., Harvey, R. G., and Albright, J. W. 1996. Herbicide timing and combination strategies for woolly cupgrass control in corn. J. Prod. Agric 9:381384.
Reith, M. and Munholland, J. 1993. A high-resolution gene map of the chloroplast genome of the red alga Porphyra purpurea . Plant Cell 5:465475.
[SAS] Statistical Analysis Systems Institute. 2000. SAS/STAT User's Guide. Version 8. Cary, NC: Statistical Analysis Systems Institute. 3884 p.
Schloss, J. V., Ciskanik, L. M., and Van Dyk, D. E. 1988. Origin of the herbicide binding site of acetolactate synthase. Nature 331:360362.
Seefeldt, S. S., Jensen, J. E., and Fuerst, E. P. 1995. Log-logistic analysis of herbicide dose-response relationships. Weed Technol 9:218227.
Smeda, R. J., Currie, R. S., and Rippee, J. H. 2000. Fluazifop-P resistance expressed as a dominant trait in sorghum (Sorghum bicolor). Weed Technol 14:397401.
SPSS. 2002. SigmaPlot® 8.0: Programming Guide. Chicago: SPSS. 320 p.
Wek, R. C., Hauser, C. A., and Hatfield, G. W. 1985. The nucleotide sequence of the ilvBN operon of Escherichia coli: sequence homologies of the acetohydroxy acid synthase isozymes. Nucleic Acids Res 13:39954010.
Westerfeld, W. W. 1945. Colorimetric determination of blood acetoin. J. Biol. Chem 161:495502.
Whitcomb, C. E. 1999. An introduction to ALS-inhibiting herbicides. Toxicol. Ind. Health 15:231239.
White, A. D., Owen, M. D. K., Hartzler, R. G., and Cardina, J. 2002. Common sunflower resistance to acetolactate synthase-inhibiting herbicides. Weed Sci 50:432437.
Young, B. G. and Hart, S. E. 1999. Woolly cupgrass management in sethoxydim-resistant corn. J. Prod. Agric 12:225228.


Evolved resistance to acetolactate synthase–inhibiting herbicides in common sunflower (Helianthus annuus), giant ragweed (Ambrosia trifida), and shattercane (Sorghum bicolor) in Iowa

  • Ian A. Zelaya and Micheal D. K. Owen (a1)


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