Genome Mutation Revealed by Artificial Hybridization between Chrysanthemum yoshinaganthum and Chrysanthemum vestitum Assessed by FISH and GISH

Present study has been done to investigate artificial interspecific crossability between Japanese Chrysanthemum yoshinaganthum (2=36) and Chinese C. vestitum (2=54), which were cultured in vitro and in vivo and characterization of their artificial hybrid chromosomes and type of changes assessed by FISH and GISH. GISH was applied by using biotin-labeled total genomic DNA probe of C. vestitum, which were mixed with blocking DNA of C. yoshinaganthum. Approximately 18 yellow-green colored chromosomes of C. vestitum were detected by the probe, approximately 18 yellow-red- mixed colored chromosomes could be common chromosomes of the two species, and nine chromosomes were relatively red of Ch. yoshinaganthum that were not detected by the probe. The expected average of FISH six signals of 5S rDNA sites and ten of 45S rDNA were observed on the chromosomes of three and six hybrid plants, respectively. Multicolor FISH signals showed unexpected average of seven and 14 yellow signals of 5S rDNA sites on seven and thirteen chromosomes simultaneous with ten and 11 red signals of 45S rDNA sites on ten and 11 chromosomes which were detected by the probes respectively. FISH mapping of the 5S rDNA at terminal sites was detected in hybrid chromosomes, for the first time. Yellow-color signals of the telomeres were detected by the biotin-labeled probe of the PCR-amplified telomeric probe in interphase and terminal sites in metaphase. All chromosomes that showed terminal signals except four chromosomes showed subterminal sites of telomeres indicating the presence of translocations.