[Cytological observation on intergeneric hybrid between Brassica. Chinensis and Crambe abyssinica]

The intergeneric hybrid from a cross between Brassica. Chinensis and Crambe abyssinica was observed with 2n=55 chromosomes in the original progenies. After several generations of in-vitro propagation by tissue culture, the chromosomes of the intergeneric hybrid were remarkably reduced, varying from 25 to 28, averaged at 26.In meiosis of the PMC of the hybrid, the average configuration of chromosome pairing was 0.06 III + 11.26 II + 3.80 I. The number of bivalents varied from 8 to 13. The majority of PMC cells showed 10 II, 11 II and 12 II bivalents with frequencies of 24.58%, 23.91% and 30.98% respectively. The number of univalents varied from 0 to 8. The reduction of chromosomes in the hybrid and the high numbers of bivalents were possibly due to the chromosome of Crambe abyssinica eliminating and the genome of Brassica. Chinensis doubling in the hybrid cells. Triade cells, chromosome lagging, and chromosome bridges were observed in anaphase II.