IBONE   05434
INSTITUTO DE BOTANICA DEL NORDESTE
Unidad Ejecutora - UE
artículos
Título:
Karyotype analysis in eight species of Vernonia ( Vernonieae, Asteraceae) from South America
Autor/es:
ANGULO, M. B.; DEMATTEIS, M.
Revista:
CARYOLOGIA
Editorial:
Universita di Firenze
Referencias:
Lugar: Roma; Año: 2009 vol. 62 p. 81 - 88
ISSN:
0008-7114
Resumen:
ABSTRACT The somatic chromosome number and karyotypes of eight species of Vernonia were analyzed. The numbers include the first chromosome count for V. hexantha Sch.Bip. (2n=30), which is diploid with base number x=15. The karyotypes are analyzed for the first time for two cytotypes of V. cognata Less. (2n=40=28m + 12sm; 2n=80=48m + 32sm), V. hexantha (2n=30=24m+6sm), V. membranacea Gardner (2n=34=24 + 10sm), V. salzmanni DC. (2n=20=10m + 10sm) and V. verbascifolia Less. (2n=20=12m + 8sm). All the species showed a predominance of metacentric chromosomes, with a lower proportion of submetacentric pairs. B chromosomes were found in V. brevifolia Less. The chromosomes varying in length from 1.25 to 3.98 µm. The differences in the symmetry of the karyotypes were small, for which it is possible to assume that the great diversification of the genus has been accompanied by very small changes in the structure of the chromosomes. Key words: chromosome numbers, karyotypes, symmetry.