Biotech Updates

Sub-Lethal Doses of Herbicide Could Prevent Transgene Escape to Weedy Brassica Species

April 30, 2014

Weedy plant species can develop herbicide resistance through different mechanism such as gene flow of herbicide resistance, transgenes from crops into compatible weedy species or by natural evolution. Previous studies suggest that sub-lethal levels of the herbicide glyphosate can alter the pattern of gene flow between glyphosate resistant canola (Brassica napus) and other glyphosate-sensitive varieties of Brassica.

Sub-lethal doses of herbicides glyphosate and glufosinate were utilized to treat Brassica crop and weed species. Phenological and developmental changes were recorded after treatment. Several vegetative and reproductive traits of these plants were also evaluated under greenhouse conditions. Exposure of Brassica species to sub-lethal dose of herbicides resulted in altering flowering phenology. Flowering was significantly delayed and male fertility was suppressed in all sensitive varieties. Higher, but still sub-lethal, levels of herbicide typically contributed to an increase in the magnitude of phenotypic changes.

Implications of altering flowering phenology would include very different pollination patterns between species as well as an altered pattern of gene flow which can prevent transgene escape to weedy relatives. However, there is also the potential for increased glyphosate resistance through natural evolution in weedy communities exposed to sub-lethal glyphosate.

Read more