Conflicting patterns of genetic and morphological variation in European Gentianella section Gentianella

Abstract

Genetics in European Gentianella Moench sect. Gentianella were investigated using internal transcribed spacer (ITS) nrDNA, trnL-F cpDNA and Amplified Fragment Length Polymorphisms (AFLP) fingerprint data to analyse relationships within the section. Both a cladistic and a phenetic approach, as well as nonhierarchical analysis (PCA) and partitioning of molecular variance (AMOVA), were used. Sequence data did not resolve groups within the section. They reflected, however, geographical isolation between central European and eastern Carpathian (G. lutescens and G. bulgarica) as well as Caucasian samples (G. caucasea). AFLP data revealed a strong differentiation within G. germanica between populations of the Alps and north-western middle Europe, although there is hardly any morphological differentiation of taxonomic significance. Morphological similarities between G. aspera and G. pilosa were not reflected in genetics, and no support was found for G. aspera. Genetic similarities were not in line with morphology in G. lutescens and G. bulgarica. AFLP data only partly resolve relationships among taxa. High genetic similarities, as well as partitioning of molecular variance among taxa/populations of eastern middle Europe (G. austriaca, G. bohemica, G. germanica, G. stiriaca) and intermediate morphological characters in G. bohemica and G. stiriaca, might indicate reticulate evolution. The overall low sequence divergence within the section points to a very young origin of all taxa.