Herbicide sensitivity of transgenic multiple herbicide‐tolerant oilseed rape

Abstract

Glyphosate and glufosinate-ammonium herbicide tolerance traits were combined into both winter and spring lines of Brassica napus L. This allowed the study of possible interactions between these transgenes in two genetic backgrounds when treated with a variety of herbicides. Selective herbicides that are commonly used within Brassica crops showed no adverse effects on the transgenic plants or their null controls. Lines containing both glyphosate and glufosinate transgenes remained tolerant to their respective herbicides, regardless of the presence of the second tolerance transgene. Lines containing only a single transgene retained tolerance to the encoded trait and did not show cross-tolerance to the second. Null lines were killed by either herbicide. All plant lines, regardless of their transgene content, were found to be equally susceptible to three herbicides (paraquat, metsulfuronmethyl and mecoprop), commonly used to remove volunteer B napus from succeeding crops and set-a-side land.

In-field frequencies and characteristics of oilseed rape with double herbicide resistance

“…The slight plant damage seen in all tested cultivars or lines if the rate of Butisan was doubled, was probably due to the fact that greenhouse-grown plants generally show greater herbicide susceptibility than plants grown in the field. Similar observations were made by Senior et al (2002), who found that the herbicide Benazolin applied to glass house plants severely damaged all lines of winter and spring oilseed rape, although this herbicide is used in the field for selective weed control in Brassica crops. Also in accordance with Senior et al (2002), we found that resistance to the complementary herbicides was not affected by the second transgene.…”

“…Similar observations were made by Senior et al (2002), who found that the herbicide Benazolin applied to glass house plants severely damaged all lines of winter and spring oilseed rape, although this herbicide is used in the field for selective weed control in Brassica crops. Also in accordance with Senior et al (2002), we found that resistance to the complementary herbicides was not affected by the second transgene. In conclusion, to control weeds in transgenic HR oilseed rape stands, not only the complementary non-selective herbicides can be used, but also the conventional selective herbicides.…”

Management of herbicide-tolerant oilseed rape in Europe: a case study on minimizing vertical gene flow

“…Whilst HT weeds can no longer be controlled by the herbicide(s) for which resistance is obtained, a set of currently used selective broad-leaf herbicides or herbicide mixtures remain effective against these HT volunteers and HT wild relatives (Tab. 2) (Beckie et al, 2001Hall et al, 2000Hall et al, , 2003Orson, 2002;Orson and Oldfield, 1999;Salisbury, 2002;Senior and Dale, 2002;Senior et al, 2002). However, farmers or seed producers converting to agricultural practices with low herbicide usage may experience problems with HT weeds.…”

“…2). HT oilseed rape volunteers and HT wild relatives are equally susceptible to and controlled by conventional herbicides commonly used (Beckie et al, 2001Hall et al, 2000Hall et al, , 2003Salisbury, 2002;Senior and Dale, 2002;Senior et al, 2002). However, the currently used herbicides have a lower efficacy in controlling volunteers compared to glyphosate and glufosinate and may lead to more persistent herbicide residues.…”

Environmental and agronomic monitoring of adverse effects due to cultivation of genetically modified herbicide tolerant crops

“…Sometimes, resistance to multiple herbicides can occur due to hybridization between cultivars with different kind of herbicide tolerance. While this can complicate volunteer control in rotational cropping, the susceptibility of the HT crop to other herbicides remains unchanged (Senior et al 2002).…”