title: Karyotypic features including organizations of the 5S, 45S rDNA loci and telomeres ofScadoxus multiflorus(Amaryllidaceae).
abstract: Scadoxus multiflorusMartyn, 1795 is an ornamental plant with brilliantly colored flowers. Even though its chromosomes are rather large, there is no karyotype description reported so far. Therefore, conventional and molecular cytogenetic studies including fluorescencein situhybridization (FISH) with 45S and 5S rDNA, and human telomere sequence (TTAGGG)nprobes (Arabidopsis-type telomere probes yielded negative results) were carried out. The chromosome number is as reported previously, 2n = 18. The nine chromosome pairs include two large submetacentric, five large acrocentric, one medium acrocentric, two small metacentric and eight small submetacentric chromosomes. Hybridization sites of the 45S rDNA signals were on the short arm ends of chromosomes #1, #3 and #8, while 5S rDNA signals appeared on the long arm of chromosome 3, in one homologue as a double signal. The telomere signals were restricted to all chromosome ends. Three chromosome pairs could be newly identified, chromosome pair 3 by 5S rDNA and chromosomes #1, #3 and #8 by 45S rDNA loci. In addition to new information about rDNA locations we show that the ends ofScadoxus multifloruschromosomes harbor human instead of Arabidopsis-type telomere sequences. Overall, theScadoxus multifloruskaryotype presents chromosomal heteromorphy concerning size, shape and 45S and 5S rDNA positioning. AsScadoxusRafinesque, 1838 and related species are poorly studied on chromosomal level the here presented data is important for better understanding of evolution in Amaryllidaceae.
authors.affiliation: Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand; Genetics and Environmental Toxicology Research Group, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Pansa
authors.initials: P
authors.lastname: Monkheang
authors.affiliation: Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand; Genetics and Environmental Toxicology Research Group, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Arunrat
authors.initials: A
authors.lastname: Chaveerach
authors.affiliation: Genetics and Environmental Toxicology Research Group, Khon Kaen University, Khon Kaen 40002, Thailand; Faculty of Law, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Runglawan
authors.initials: R
authors.lastname: Sudmoon
authors.affiliation: Genetics and Environmental Toxicology Research Group, Khon Kaen University, Khon Kaen 40002, Thailand; Faculty of Environment and Resource Studies, Mahasarakham University, Maha Sarakham 44150, Thailand.
authors.forename: Tawatchai
authors.initials: T
authors.lastname: Tanee
keywords: Scadoxus multiflorus; aceto-orcein staining; fluorescence in situ hybridization (FISH); rDNA; telomere