Caryological analysis of Soth american species of Vernonia (Vernonieae, Asteraceae)

ANGULO, M. B.; DEMATTEIS, M.

Plant Biosystems

Società Botanica Italiana

Lugar: Roma; Año: 2007

1126-3504

In the present study 16 populations belonging to 13 species of the genus Vernonia Schreb. were exarnined cytologically. In total were found six different chromosome numbers, which represent three basic numbers: x=10, x=16 and x=17. These results include the first chromosome number reports for the following four species: V lanifera Cristbbal& Dematt. (2n=2x=32), Y membranacea Gardner (2n=2x=34), V salzmannii DC. (2n=2x=20) and V scabrifolzata Hieron. (2n=2x=128). Besides, a new chromosome number was found in V saltenszs Hieron. (2n=2~32), for which only tetraploid populations have been previously recorded. The data obtained in this work, along with the information available at the literature show that the genus Vernonia in South America is heterogeneous with basic chromosome numbers that range between x=9 and x= 1 9 . These numbers suggest that the combination of polyploidy and aneuploidy has played an important role in the evolution of the genus Vernonia.