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

AAGENSEN, L.; GIUSSANI L. M.; SCATAGLINI, M. A.; MORRONE, O.

Oaxaca

Congreso; XXV Meeting of the Willi Hennig Society; 2006

Willi Hennig Society

With the optimization of continuous 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 continuous 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 continuous and 14 qualitative characters. We use TNT to reanalyze this data set adding DNA sequence data. The analysis implies rescaling of the continuous 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 detecting minor changes in branch support were used to evaluate the results.