Intervarietal chimera formation in cabbage. (Brassica oleracea L.)

A histological and genetical study was done on intervarietal graft chimeras between "Yo-shin kanran" (green colored) and "Murasaki kanran" (purple colored) in cabbage (Brassica oleracea). When the anthocyanin pigmentation pattern of the chimeric tissues was observed, epidermal and subepidermal cells were mosaic and recognized to be more complicated than the external appearance. The genotypic constitution of germ cells in chimera plants (V0, V1) was studied through the segregation pattern of anthocyanin pigmentation in progeny plants derived from each capsule obtained by geitonogamy of chimeras and back crosses with the green parent "Yoshin kanran" and purple parent "Murasaki kanran". No segregation of plant color was observed in most of the progenies of two V0 chimera plants as well as their vegetatively propagated V1 chimera platnts. However, segregations were observed in the progeny plants from two capsules of one V0 chimera plant crossed with "Murasaki kanran" and from two capsules of one V1 chimera plant by geitonogamy. These segregation phenomena in the progeny plants suggest two possibilities. The first possibility is the chimericity of the germ cell layer in a single flower of the parental chimera plant, the second is gene transfer between different tissues or cells.