title: Genome sizes for all genera of Cycadales.
abstract: Nuclear DNA content (2C) is reported for all genera of the Cycadales, using flow cytometry with propidium iodide. Nuclear DNA content ranges from 24 to 64 pg in cycads. This implies that the largest genome contains roughly 40 × 10(9) more base pairs than the smallest genome. The narrow range in nuclear DNA content within a genus is remarkable for such an old group. Furthermore, 42 of the 58 plants measured, covering five genera, have 18 chromosomes. They vary from 36.1 to 64.7 pg, covering the whole range of genome sizes (excluding the genome of Cycas). Hence, their does not seem to be a correlation between genome size and the number of chromosomes.
authors: Netherlands Centre for Biodiversity Naturalis, Herbarium section, Leiden, The Netherlands. zonneveld@NHN.leidenuniv.nl
authors: B J M
authors: BJ
authors: Zonneveld
mesh_terms: D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D032462:Cycadopsida / Q000235:genetics*; D018744:DNA, Plant / Q000235:genetics; D005434:Flow Cytometry / Q000379:methods; D014644:Genetic Variation; D059646:Genome Size; D018745:Genome, Plant; D010802:Phylogeny; D011123:Polyploidy
chemical_list: D018744:DNA, Plant