Flow cytometric evidence for endopolyploidization in cabbage (Brassica oleracea L.) flowers

Flow cytometric analysis of the nuclear DNA contents of somatic tissues fro m flowers of cabbage (Brassica oleracea L.) revealed extensive endoreduplic ation, resulting in tissues that contain cells with multiple ploidy levels (also called 'endopolyploidy'). Multiples of the haploid nuclear genome com plement (1C) corresponding to 2C, 4C, 8C, 16C, 32C and 64C were observed in mature flowers. The distribution of cells with the differerent ploidy leve ls is tissue-specific and is characteristic of the stage of development. Nu clei of young flower buds exclusively Save 2C and 4C peaks, indicating that the tissues maintained diploid level. Endoreduplication was consistently d etected during flower development. Endopolyploidy is probably common in dif ferentiation of cabbage plants. Implications of this original feature are d iscussed.