[Truncated abstract] Herbicide resistance has become a major issue in all cropping regions of Australia, due to heavy reliance on herbicides for weed control. History has shown that the trend for increasing herbicide resistance in Australian cropping systems is likely to continue, at least in the near future. One of the most noxious resistant weed species, threatening herbicide sustainability in the Australian agricultural industry are wild oats (Avena spp.). These grass species have evolved resistance to ACCaseinhibiting herbicides, as well as more recent resistance to ALS-inhibiting herbicides and Group Z (unknown mode-of-action) herbicides. Hexaploid wild oats (Avena fatua and A. sterilis, 2n = 6x = 42) are among the world's worst agricultural weeds. In Australia, wild oats infest many cropping regions, costing farmers million of dollars every year through crop yield loss and weed control costs. ACCase-inhibiting herbicides have been used extensively since the late 1970s for wild oat control, but repeated use of these herbicides has resulted in resistance evolution in wild oat populations. Rendered by the complexities in gene transcription/expression and interaction across genomes in a polyploid species, resistance evolution in polyploids species can be far more complicated than in diploids. Until now, most fundamental studies of herbicide resistance have been with diploid species, whereas our understanding on the evolution of herbicide resistance in polyploid weeds is rather limited. In this study, a series of experiments employing biochemical, molecular and genetic approaches were conducted to understand resistance mechanisms and evolution in ACCase-inhibiting herbicide-resistant hexaploid wild oat populations collected from the Western Australian grain belt.
|Qualification||Doctor of Philosophy|
|Publication status||Unpublished - 2013|