Karyotype Diversification and Evolution in Diploid and Polyploid South American Hypochaeris (Asteraceae) Inferred from rDNA Localization and Genetic Fingerprint Data

Abstract

Early evolution of Hypochaeris in South America was characterized by considerable karyotype differentiation resulting from independent derivations from an ancestral karyotype. There was marked diversification with respect to the position and evolution of the 35S rDNA locus on chromosome 3, probably involving inversions and/or transpositions, and on chromosome 2 (rarely 3) concerning inactivation and loss. Among these different karyotype assemblages, the apargioides group and its derivatives constitute by far the majority of species.