title: Genome size variation in Begonia.
abstract: The genome sizes of a Begonia collection comprising 37 species and 23 hybrids of African, Asiatic, Middle American, and South American origin were screened using flow cytometry. Within the collection, 1C values varied between 0.23 and 1.46 pg DNA. Genome sizes were, in most cases, not positively correlated with chromosome number, but with pollen size. A 12-fold difference in mean chromosome size was found between the genotypes with the largest and smallest chromosomes. In general, chromosomes from South American genotypes were smaller than chromosomes of African, Asian, or Middle American genotypes, except for B. boliviensis and B. pearcei. Cytological chromosome studies in different genotypes showed variable chromosome numbers, length, width, and total chromosome volume, which confirmed the diversity in genome size. Large secondary constrictions were present in several investigated genotypes. These data show that chromosome number and structure exhibit a great deal of variation within the genus Begonia, and likely help to explain the large number of taxa found within the genus.
authors: Institute for Agricultural and Fisheries Research (ILVO), Plant Sciences Unit, Caritasstraat 21, 9090 Melle, Belgium. angelo.dewitte@katho.be
authors: Angelo
authors: A
authors: Dewitte
authors: Leen
authors: L
authors: Leus
authors: Tom
authors: T
authors: Eeckhaut
authors: Ives
authors: I
authors: Vanstechelman
authors: Johan
authors: J
authors: Van Huylenbroeck
authors: Erik
authors: E
authors: Van Bockstaele
mesh_terms: D031112:Begoniaceae / Q000235:genetics* / Q000502:physiology; D032461:Chromosomes, Plant / Q000235:genetics*; D018744:DNA, Plant / Q000235:genetics*; D014644:Genetic Variation; D018745:Genome, Plant / Q000235:genetics*; D011058:Pollen / Q000235:genetics / Q000502:physiology
chemical_list: D018744:DNA, Plant