Normal and Cytoplasmic Male Sterile (Raphanus Sativus Cytoplasm) Lines of Brassica Napus Present Different Chloroplast DNA Restriction Maps and Different CF1-ß Subunits

Cytoplasmic male sterility of the rapeseed B. napus arose from intergeneric crosses involving a cytoplasmic male sterile (cms) radish (Vedel et al., 1982). The cms lines of B. napus present two maternally inherited traits, cytoplasmic male sterility and chlorophyll deficiency both resulting from interactions between the nuclear genetic system of B. napus and organellar genetic ones of radish. Preliminary data on restriction endonuclease analysis of cp DNA and 2-D electrophoresis of chloroplast polypeptides have revealed marked differences between normal (N) and cms lines (Vedel and Mathieu, 1983; Remy and Ambard-Bretteville, 1983). In this paper, we present (1) physical maps for each type of B. napus cp DNA using five restriction enzymes and gene mapping of rRNA and of five protein genes; (2) bidimensional electrophoresis of thylakoid polypeptides with an attempt to explain different IEF mobilities between N and cms s subunits of the CF1.