Correction of chlorophyll-defective, male-sterile winter oilseed rape (Brassica napus) through organelle exchange: Phenotypic evaluation of progeny

Introduction of male-sterile Raphanus sativus cytoplasm into Brassica napus results in a chlorophyll deficiency in the backcrossed male-sterile B. napus line. We describe the apparent correction of this defect by protoplast fusion. enabling somatic recombination and/or elimination of organelles. Methods for fusion of male-sferile and male-fertile protoplasts, and for regeneration of plants are described. Potential recombining ability in somatic fusions is shown to be influenced by the genotypes, with one combination of genotypes resulting in five times more plants than the least successful combination. Of 87 plants that were regenerated. 44 have been analyzed for ploidal level and organellar composition. Two of the 44 plants were found to be male sterile with a green phenotype. The behaviour of these plants was followed during two subsequent seed generations.