All 45S rDNA loci were homotopic to CMA-positive regions. And they always co-localized with 45S rDNA locus. All accessions possessed one 5S rDNA locus except for hongkyul, which displayed two 5S rDNA loci. The distributions of 5S and 45S rDNA loci by FISH were heterogeneous among them. In contrast, the type D and E chromosomes were remarkably constant and predominantly observed in all accession. The numbers of type A, B, and C chromosomes were lower in all accessions. All types of chromosome bands were present in all accessions except in hongkyul, in which type A chromosome was absent but two of type F chromosomes were observed. pseudogulgul), 1 A+3B+1C+7D+6E in dangyooza (C. tachibana), 2 A+1B+3C+4D+8E in sadoogam (C. erythrosa), 3B+1C+7D+5E+2 F in hongkyul (C. The CMA banding patterns of the five Korean landrace citrus were 1 A+2B+2C+6D+7E in dongjeongkyul (C. Metaphase chromosomes of five Korean landrace citrus were analyzed to understand the phylogenetic relationship among them and to compare these characteristics with those of other Citrus species including previously reported six Korean landrace mandarins at a cytogenetic level using CMA banding patterns and rDNA loci. Heterozygous karyotypes of six accessions separated and differentiated each of the six Korean landrace mandarins and potential marker chromosomes were identified. leiocarpa) (1A/45S + 1C + 6D + 2D/45S + 2D/5S-45S + 6E) seemed to be related to mandarins and pummelos. tangerina) (3B/45S + 2C + 7D + 1D/5S-45S + 5E) suggests that the pyunkyul mandarin is a hybrid between C. Cheongkyul mandarin possessed a distinct marker chromosome (D/45S) that can be used to distinguish cheongkyul madrarin from the other Korean landrace mandarins. The chromosome composition of byungkyul mandarin based on CMA banding pattern and rDNA loci suggests that byungkyul mandarin may be related to pummelo, sweet orange, and members of the Citrus subgenus Papeda during its evolution. A solitary 5S rDNA locus was observed in the chromosomes of byungkyul mandarin (C. benikoji) displayed the 1A/45S + 2B/45S + 2C + 5D + 1D/45S + 1D/5S-45S + 6E pattern, without a solitary 5S rDNA locus that differentiated the gamza mandarin from other accessions. Chromosomes were categorized into five types according to the distribution and number of heterochromatic CMA-positive bands type A chromosomes have two telomeric and one proximal bands, type B have one telomeric and one proximal bands, type C have two telomeric bands, type D have one telomeric band, and type E have no band. In this study, metaphase chromosomes of six Korean landrace mandarins were analyzed to understand the phylogenetic relationship among them and to compare these characteristics with those of other Citrus species at a cytogenetic level using CMA banding patterns and rDNA loci. Landrace Citrus species represent broad and natural genetic variability, which are important and valuable as genetic material. Mandarin is the major type of citrus grown in Jeju, Korea and has a long history of cultivation there. medica is a true species while the other nine accessions are hybrids. These data support the hypothesis that C. The lemons and limes were heterozygous for all rDNA sites, whereas C. The analysis of the distribution of rDNA sites allowed a further refinement of the comparison among accessions. Citrus medica was the only homozygous accession of this group and all of its chromosome types were clearly represented in limes and lemons, some of them forming heteromorphic pairs. aurantifolia, the presence of a chromosome type unknown in all other Citrus species cytologically known so far supports the assumption that this accession may be derived from a hybrid with a species from the subgenus Papeda or from another genus. limettioides, seemed less related to each other and exhibited different heteromorphic chromosome pairs. limon by the absence of a single chromosome with one band in each telomere. volkameriana displayed karyotypes very similar to each other, but they differed from C. limon analyzed showed the same pattern of CMA+ bands and rDNA sites, suggesting that they originated from a single germplasm, later differentiated by distinct somatic mutations. In order to identify karyotypic similarities and species relationships within this group, the CMA+/DAPI- banding pattern and the distribution of the 5S and 45S rDNA sites of 10 accessions of lime, lemon, and citron were investigated. Lemons, limes and citron constitute a group of closely related Citrus species, whose species delimitations and taxonomic relationships are unclear.
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