[Objective] This study aimed to compare the similarities and dissimilarities in karyotypes of purple and white onions,so as to lay foundation for further studying its genetic improvement and breeding more onion variet...[Objective] This study aimed to compare the similarities and dissimilarities in karyotypes of purple and white onions,so as to lay foundation for further studying its genetic improvement and breeding more onion varieties.[Method] Sections of root-tip cells were prepared by normal wafer method.Photomicrography was adopted to produce the high-quality chromosome specimen.Finally,karyotype analysis was conducted using Adobe Photoshop.[Result] Chromosome karyotype analysis on the root-tip showed that the chromosome number of both purple and white onions was 2n=2x=16.Among the 16 chromosomes of both the onions,no satellite chromosome was found.By measuring and calculating,it was found that the karyotype of the studied white union belonged to the lowly evolutional 2A type,and its karyotype formula was 2n=2x=16=14 m ＋2St,with the karyotype asymmetry coefficient of 58.67%.No obvious centromere was observed in the sections of purple onion.[Conclusion] The karyotypes of white and purple unions are similar and we can infer from this fact that the reason of different characters between both the onions is not due to the chromosome aberration.This karyotype formula and asymmetrical karyotype coefficient have some reference values on the identification of onion variety resources.展开更多
基金Supported by Scientific Research Foundation for Doctors of Qufu Normal University~~
文摘[Objective] This study aimed to compare the similarities and dissimilarities in karyotypes of purple and white onions,so as to lay foundation for further studying its genetic improvement and breeding more onion varieties.[Method] Sections of root-tip cells were prepared by normal wafer method.Photomicrography was adopted to produce the high-quality chromosome specimen.Finally,karyotype analysis was conducted using Adobe Photoshop.[Result] Chromosome karyotype analysis on the root-tip showed that the chromosome number of both purple and white onions was 2n=2x=16.Among the 16 chromosomes of both the onions,no satellite chromosome was found.By measuring and calculating,it was found that the karyotype of the studied white union belonged to the lowly evolutional 2A type,and its karyotype formula was 2n=2x=16=14 m ＋2St,with the karyotype asymmetry coefficient of 58.67%.No obvious centromere was observed in the sections of purple onion.[Conclusion] The karyotypes of white and purple unions are similar and we can infer from this fact that the reason of different characters between both the onions is not due to the chromosome aberration.This karyotype formula and asymmetrical karyotype coefficient have some reference values on the identification of onion variety resources.
