Field evaluation of herbicide-resistant transgenic broccoli

This study examined the field performance and herbicide resistance of lines of broccoli (Brassica oleracea Italica Group) generated from plants transformed for resistance to the herbicide glufosinate by Agrobacterium-mediated gene transfer. Seedling vigor and vegetative growth characteristics of the first recombinant generation (R-1) produced by selfing the transformed lines were comparable to those of the F-1 parent (cv. Cruiser) and an equivalent nontransformed F-2 line. In hand-needed trials, marketable yields of the R-1-transformed lines were comparable to the parental line or the corresponding nontransformed F-2 line. A single application of the recommended rate of the nonselective herbicide glufosinate slowed the growth and reduced yields of nontransformed broccoli, but had little effect on head quality or yields of most transformed lines. Inheritance of herbicide resistance in the R-1 progeny of the R-0 transgenic plants followed standard Mendelian ratios for a completely dominant trait controlled by a single gene. The results confirm the potential for improvement of broccoli through the incorporation of herbicide resistance by gene transfer technology. Chemical name used: 2-amino-(4-hydroxymethylphosphinyl)butanoic acid (glufosinate, phosphinothricine).