Response of Genotypes of Brassica napus on Chromosome Doubling Through Treating in Vitro Microspores with Colchicine

The chromosome doubling response of microspore-derived plants of varieties of genotypes in Brassica napus was studied by treating isolated microspores with colchicine. Isolated microspores were cultured in NLN medium containing 10、20、50 or 100 mg/L colchicine for 24 h or 48 h ,then cultured in the same colchicine-free medium to induce embryogenesis. The ratio of doubled haploid plants derived from treated microspores of 21 genotypes ranged from 23. 94% to 99. 42%. The results of deviance analysis showed that chromosome doubling rate of the similar genotypes was not significantly different, whereas significant difference was identified among some distinct genotypes. This indicated that different response existed in some distinct genotypes to chromosome doubling through treating in vitro microspores with colchicine.