A possible origin for the sugar beet cytoplasmic male sterility source Owen

The cytoplasmic male sterility source of sugar beet used for hybrid seed production is distinguished from the maintainer (O type) by the HindIII chloroplast DNA (ctDNA) restriction pattern. We searched the genus Beta for a putative species carrying the same ctDNA as the Owen cytoplasmic male sterility source. Each of the three sections of this genus displays a specific HindIII profile for ctDNA. We, therefore, suggest the putative species be classified to the Vulgares section as the sugar beet. An old variety of the garden beet, "Crapaudine', in our collection carries the same ctDNA restriction profile as the Owen cytoplasmic male sterility source. This variety presumably was never crossed by breeders with either the Owen cytoplasmic male sterility line or the sugar beet. Our results, however, allow us to propose that the origin of the Owen cytoplasmic male sterility was through a cross of the 'Crapaudine' variety, as female, from the Semaphor company.Key words: cytoplasmique male sterility, sugar beet, chloroplast DNA, garden beet, wild species.