Resistance to Glyphosate in a Population of Lolium Rigidum
Lolium rigidum is a grass weed which is widely established throughout the cropping regions of Southern Australia. It has displayed a marked propensity to evolve resistance to herbicides and, indeed, there now exist some populations which have become resistant to most of the major herbicide chemistries used in Australia (Preston et al 1996; Powles et al 1997). Until recently glyphosate has seemed relatively immune to this problem. However, it now seems that at least two populations of lolium rigidum have evolved resistance in response to the repeated use of glyphosate over many years (Pratley et al 1996; Powles et al 1998). In the case of the population described by Powles et al, glyphosate failed to control a population of lolium rigidum in an orchard in Orange, NSW, Australia following 15 years of previously successful use. Resistance was confirmed in pot dose experiments and survivors of a treatment of 450 g ai ha−1 were further intercrossed to yield a population which consistently exhibited 7–11s fold resistance when compared to the survival rates of a standard susceptible population. Here we describe the results of a study aimed to elucidate the mechanism of this recently evolved resistance.
KeywordsSusceptible Plant Grass Weed Benzenesulfonyl Fluoride Diclofop Methyl Waite Campus
Unable to display preview. Download preview PDF.
- Boerboom, CM et al (1990) Weed Science, 38, 463–467.Google Scholar
- Hawkes, TR et al (1993) in Proc. Brighton Crop. Conf, 2, 739–744Google Scholar
- Pratley J et al (1996) in ‘Proceedings of the 11’th Annual Conference of the GrasslandsGoogle Scholar
- Society of NSW’ (J. Virgona and D. Michalk, eds) (The Grasslands Society of NSW, Inc., Wagga Wagga, Australia) p 122Google Scholar
- Powles, SB et al (1998) Weed Sci. (in press)Google Scholar
- Preston C et al (1996) in ‘Herbicide Resistance: Biology and Biochemistry’ (T.M. Brown, ed) American Chemical Society, Washington, DC, pp 117–129Google Scholar
- Sambrook, J et al (1989) Molecular cloning — a laboratory manual. Cold Spring Harbour press, 2nd edition.Google Scholar
- Siehl, DL (1997) in ’Herbicide Activity: Toxicology, Biochemistry and Molecular Biology’ (R.M. Roe et al ed.) IOS press, pp 37–66.Google Scholar
- Steinrucken, HC, Amrhein, N (1984) EMBO J., 143, 351–357Google Scholar