Sulfonylurea, resistance

The first ALS-resistant weeds were reported in 1987 when prickly lettuce (Mallory-Smith, 1990 Mallory-Smith et al, 1990b) and kochia (Primiani et al, 1990) control failures occurred in Idaho and Kansas, respectively, after 5 consecutive years of chlorsulfuron use. The kochia biotype proved to be cross-resistant to six other ALS-inhibitor herbicides, including sulfonylureas and imidazolinones. Within 5 years, sulfonylurea-resistant kochia had been identified at 832 sites in 11 states of the United States and in three Canadian provinces (Saari et al, 1994). ALS inhibitor-resistant kochia and Russian thistle have become widespread problems in cereal-producing regions of northwestern United States and Canada. The mobility of these tumble weeds as plants with mature seeds or pollen carried by wind has undoubtedly contributed to the rate at which resistance has spread. 

In Australia, two types of sulfonylurea resistance have been reported (Bumet et al, 1994). Rigid ryegrass exhibited cross-resistance to certain sulfonylurea and imidazolinone herbicides following selection for resistance to other... 

Burnet, M.W.M., J.T. Christopher, J.A.M. Holtum, and S.B. Powles (1994). Identification of two mechanisms of sulfonylurea resistance within one population of rigid ryegrass (Lolium rigidum) using a selective germination medium. Weed Sci., 42 468 173. 

Christoffoleti, P.J., P. Westra, and F. Moore III (1997). Growth analysis of sulfonylurea-resistant and -susceptible kochia (Kochia sco-paria). Weed Sci., 45 691-695. 

Lovell, S.T., L.M. Wax, M.J. Horak, and D.E. Peterson (1996b). Imidazolinone and sulfonylurea resistance in a biotype of common waterhemp (Amaranthus rudis). Weed Sci., 44 789-794. 

Stallings, G.P., D.C. Thill, C.A. Mallory-Smith, and B. Shafii (1995b). Pollen-mediated gene flow of sulfonylurea-resistant kochia (Kochia scoparia). Weed Sci., 43 95-102. 

TABLE II. Herbicide Resistant Callus Following Co-Uptake of Kanamycin Resistance and Sulfonylurea Resistance Genes... 

There are two commercially available herbicide resistant traits in soybean, glypho-sate resistance (Roundup Ready , RR) and sulfonylurea resistance (STS ). Herbicide resistance now accounts for over 90% of approximately 73 million total soybean acres grown in the United States (Fig. 6.1.2) [6]. 

McSheffrey, S.A., McHughen, A., Devine, M.D., 1992. Characterization of transgenic sulfonylurea-resistant flax (linum usitatissimum. Theor. Appl. Genet. 84, 480-486. 

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