TAXONOMIC AND EVOLUTIONARY RELEVANCE OF KARYOTYPE IN GENUS CHAETANTHERA(ASTERACEAE): PRELIMINARY EVIDENCE IN CHILEAN SPECIES

Abstract

Chaetanthera is an exclusively South American genus comprising 42 species approximately. Although being a genus
taxonomically well-studied, there are discrepancies with the evolutionary studies that have been made about it. The most
recent taxonomic study of Chaethanthera was published by Cabrera in 1937 recognizing seven subgenera, based on the
habit and involucre bracts characteristics. However, in the only phylogenetic study about the genus, these groups are
paraphyletic. In the present work, karyotypical characteristics of Chaetanthera moenchioides are given and comparisons
with other five species of Chaetanthera are done. The results are discussed from taxonomic and evolutionary perspective.
Although preliminary, karyotypical evidence is congruent with the phylogenetic results corroborating to Chaetanthera
as a paraphyletic subgenus and indicating that changes in the karyotype of Chaetanthera would occurred with decrease
in chromosome number. On the other hand, there could be a decrease of the length of total genome and an increase of
asymmetric karyotypes in species that are growing in high altitude.