Karyological circumscription of Ipheion Rafinesque (Gilliesioideae, Alliaceae)

Autor: Luiz Gustavo Rodrigues Souza, Orfeo Crosa, Marcelo Guerra
Rok vydání: 2010
Předmět:
Zdroj: Plant Systematics and Evolution. 287:119-127
ISSN: 1615-6110
0378-2697
DOI: 10.1007/s00606-010-0304-3
Popis: Ipheion Rafinesque is a small genus formed by I. uniflorum (2n = 12, 2SM + 10A), I. tweedieanum (2n = 14A), and I. recurvifolium (2n = 20, 4SM + 16A). Three species of Nothoscordum, N. felipponei, N. hirtellum, and N. vittatum (2n = 10, 6M + 4A), were also later transferred to Ipheion based on the common presence of unifloral inflorescence. Karyotype analysis of the five former species was performed in this work, aiming to evaluate the circumscription of the genus. This analysis was based on chromosome size and morphology, asymmetry index, staining with chromomycin A3 (CMA) and 4′,6-diamidino-2-phenylindole (DAPI), and in situ hybridization with 5S and 45S rDNA probes. Tetraploid populations of I. uniflorum, probably autopolyploids of recent origin, with karyotype similar to the diploids, are described herein for the first time. Grouping analyses of the several sets of characters analyzed show the former three Ipheion species clearly separated from the Nothoscordum ones, which were more proximally related to other Nothoscordum species. Chromosome size, asymmetry indices, and number and position of 5S and 45S rDNA sites were the most important karyotype characters to define the genus Ipheion. These data indicate that the unifloral species of Nothoscordum belong to Nothoscordum and not to Ipheion, and the “unifloral inflorescence” should be a homoplasy common to both genera.
Databáze: OpenAIRE