Transfer of resistance to race 2 of Plasmodiophora brassicae from Brassica napus to cabbage (B. oleracea ssp. capitata). III. First backcross and F2 progenies from interspecific hybrids between B. napus and B. oleracea ssp. capitata

Transfer of resistance to race 2 of Plasmodiophora brassicae from Brassica napus to cabbage (B. Oleracea spp. Capitata). IV. A resistant 18-chromosome B1 plant and its B2 progenies

“…Plant B,-A-l bears only half-open flowers with shrunken anthers which shed practically no pollen (CHIANG et al, 1979b). The pollen stainability was 6.78 %.…”

“…selected in a field trial (CHIANG et al, 1979b). This particular B, plant, referred to henceforth as B,-A-l not only has a desirable low chromosome number (2n = 18) but also shows close resemblance to its cabbage parent.…”

Opportunities for gene transfer from transgenic oilseed rape (Brassica napus) to related species

“…Many studies of Brassica napus have involved the use of interspecific hybrids in experiments to define the taxonomic relationships within the Brassiceae family (Karpechenko, 1922;Pearson, 1928;Sinskaia, 1928;Morinaga, 1929a, b) and to study chromosome pairing and behaviour (Catchside, 1934;U, 1935;Haga, 1938;Sikka, 1940;Mizushima, 1950a;Harberd, 1972Harberd, , 1976. Interspecific hybridizations have also been attempted to evaluate the potential for gene transfer (Heyn, 1977;Ringdahl et al, 1987), and several genes have been successfully transferred into B. napus from other species (Lammerink, 1970;Johnston, 1974;Chiang et al, 1979;Roy, 1984). Some recent studies have been aimed at evaluating the potential for transfer of transgenes between oilseed rape and specific recipient species (Bing et al, 1991;Chevre et al, 1992;Kerlan, 1992a, b;Lefol, 1993;Eber et al, 1994).…”

Transfer of resistance to race 2 of Plasmodiophora brassicae from Brassica napus to cabbage (B. Oleracea ssp. capitata). V. The inheritance of resistance

“…The chromosome numbers of the B3 and B4 plants were determined by counting the somatic number in either tapetal or nucellar cells. The procedures have been described previously (CHIANG et al, 1979a(CHIANG et al, , 1979b. Meiotic chromosomes behaviour was examined in the PMCs of flower buds collected from nine male sterile and six male fertile B4 plants, 25 to 50 cells were examined in each plant (male fertility restoration in backcross progenies will be reported in a separated paw).…”

“…Only two Bi plants, designated Bi-17 and Bi-20, were found with 26 chromosomes (CHIANG et al 1979b). In order to eliminate the extra al and cl chromosomes from backcrosses progenies, these two 26-chromosome Bi plants were selected to backcross with diploid cabbage.…”