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应用25S rDNA-FISH对大白菜—结球甘蓝异源三倍体(ACC)中期染色体组成和减数分裂染色体行为进行了分析,并进行了花粉特性和结实性的研究。结果表明,大白菜—结球甘蓝异源三倍体染色体数为28,含有9个25S rDNA位点,其中4个来自结球甘蓝4号和7号染色体;5个来自大白菜1~5号染色体;A、C基因组间不同染色体同源程度不同,减数分裂终变期常形成单价体、二价体和三价体等不同的联会方式;中期Ⅰ和中期Ⅱ存在游离染色体;后期Ⅰ和后期Ⅱ染色体分离不均衡,并存在染色体落后或丢失;末期Ⅱ有微核产生。异源三倍体花粉整齐度和生活力远低于其二倍体亲本,自交及与亲本甘蓝(CC)回交的结籽率都极低,仅为0.01%。
The chromosomal behavior of metaphase chromosomes and meiosis of Chinese cabbage-cabbage allotriploid (ACC) were analyzed by 25S rDNA-FISH, and the pollen characteristics and seedability were studied. The results showed that the number of chromosomes in Chinese cabbage - Brassica oleifera was 28, containing 9 25S rDNA loci, of which 4 came from chromosome 4 and 7 and 5 from cabbage 1 to 5 Chromosomes; Different genotypes of A and C genomes have different degrees of homology. The final stage of meiosis often forms different associations such as monovalent, bivalent and trivalent; there are free chromosomes in metaphase I and interphase II; And late Ⅱ chromosome imbalance, and the existence of chromosomes behind or lost; end Ⅱ micronucleus. Heteroautotriploid pollen uniformity and viability were much lower than those of diploid parents, and the selfing and backcrossing rate with the parent cabbage (CC) was very low, only 0.01%.