论文部分内容阅读
[目的]分析紫色洋葱和白色洋葱的核型并比较他们的异同点,为进一步研究洋葱遗传改良奠定基础,为培育洋葱新品种提供理论依据。[方法]运用传统的压片技术制备洋葱根尖细胞染色体标本后进行核型分析。[结果]通过对紫色洋葱和白色洋葱根尖细胞的核型分析,发现两种洋葱的染色体数均为2n=2x=16,其中均末发现具有随体的染色体。通过对白色洋葱的染色体进行测量和计算发现其核型均属进化程度较低的2A型,核型公式为2n=2x=16=14m+2St(SAT),核型不对称系数58.67%;而紫色洋葱的染色体制片由于无明显的着丝粒,故有待于进一步的研究。[结论]2种洋葱的核型相似,说明两者的性状差异不是由染色体变异造成的,需要做进一步的研究;该试验得到的核型公式及核型不对称系数对我国洋葱品种资源的系统分类和遗传育种研究具有一定的参考价值。
[Objective] The research aimed to analyze the karyotypes of purple onions and white onions and compare their similarities and differences so as to lay a foundation for further study on genetic improvement of onions and provide a theoretical basis for cultivating new onion varieties. [Method] The karyotypes of onion root tip cell chromosome specimens were prepared by using traditional tabletting technique. [Result] Through the karyotype analysis of the root tip cells of purple onion and white onion, it was found that the chromosome numbers of the two onions were 2n = 2x = 16, and the chromosomes with the accompaniment were all found. The karyotypes of the white onions were all 2A type with low degree of evolution. The karyotype formula was 2n = 2x = 16 = 14m + 2St (SAT), and the karyotype asymmetry coefficient was 58.67% Purple onion chromosome preparation due to no obvious centromere, it needs further study. [Conclusion] The karyotypes of the two onions were similar, which indicated that the difference of traits between the two onions was not caused by chromosomal variation and further study was needed. The karyotype formula and karyotype coefficient Classification and genetic breeding research has some reference value.