Transfer of auxinic herbicide resistance from to and through embryo rescue.

Auxinic herbicides are widely used in agriculture to selectively control broadleaf weeds. Prolonged use of auxinic herbicides has resulted in the evolution of resistance to these herbicides in some biotypes of (wild mustard), a common weed in agricultural crops. In this study, auxinic herbicide resistance from was transferred to and , two commercially important crops, by traditional breeding coupled with embryo rescue. A high frequency of embryo regeneration and hybrid plant establishment was achieved. Transfer of auxinic herbicide resistance from to the hybrids was assessed by whole-plant screening of hybrids with dicamba, a widely used auxinic herbicide. Furthermore, the hybrids were tested for fertility (both pollen and pistil) and their ability to produce backcross progeny. The auxinic herbicide-resistant trait was introgressed into by backcross breeding. DNA ploidy of the hybrids as well as of the backcross progeny was estimated by flow cytometry. Creation of auxinic herbicide-resistant crops by non-transgenic approaches should facilitate effective weed control, encourage less tillage, provide herbicide rotation options, minimize occurrence of herbicide resistance, and increase acceptance of these crops.