Evidence for hybridization and introgression in Hybanthus arenarius Ule and H. calceolaria (L.) Oken (Violaceae) from allozyme markers and multivariate morphometric analysis

Abstract

Allozyme and multivariate morphometric analyses using 46 morphological characters were carried out in 41 individuals of Hybanthus arenarius, 25 individuals of H. calceolaria and 33 morphologically intermediate individuals occurring on the campus of the Universidade Estadual de Feira de Santana to quantify the variability within these populations and to test hypotheses of hybridization and introgression. H. arenarius could be well differentiated in the morphometric analysis from both intermediate and H. calceolaria individuals, but the latter two groups could not be separated. Those same relationships were found in the allozyme analysis. The lack of diagnostic loci does not allow definitive confirmation of natural hybridization between the two species. However, several results found in the morphometric and genetic analyses reinforce the hypothesis that the individuals considered formerly as intermediate are actually individuals of H. calceolaria introgressed from H. arenarius.