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 (R1) produced by selfing the transformed lines were comparable to those of the F1 parent (cv. Cruiser) and an equivalent nontransformed F2 line. In hand-weeded trials, marketable yields of the R1-transformed lines were comparable to the parental line or the corresponding nontransformed F2 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 R1 progeny of the R0 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).