Characters sampling at low taxonomic level - a phylogenetic analysis of species complex Poa sect. Dioicopoa

AAGESEN, LONE; GIUSSANI, LILIANA M.; SCATAGLINI, AMALIA; MORRONE, OSVALDO

Oaxaca Mexico

Congreso; XXV Willi Hennig Society Meeting; 2006

Willi Hennig Society

With the optimization of continuos characters now made possible within a cladistic context, phylogenetic studies can proceed to analyze groups that have previously been untreatable such as species complexes in which the species are only defined through the variation of continuos characters. We explore character sampling in a species complex of bluegrasses, Poa sect. Dioicopoa, in which sexual dimorphism and the lack of adequate qualitative characters complicate an analysis at species level. Dioicopoa has previously been analyzed through a multivariate analysis using 29 continuos and 14 qualitative characters. We use TNT to reanalyze this data set adding DNA sequence data. The analysis implies rescaling of the continuos characters in order to transform measurements such as culm length (mean 12-77 cm) and stomata length (mean 0.03-0.05 mm) into a comparable scale. Resampling methods suitable for detectecting minor changes in branch support were used to evaluate the results.