Molecular Systematics of the Genus Uvularia and Selected Liliales Based upon matK and rbcL Gene Sequence Data

To elucidate the affinity and phylogeny of the endemic North American genus Uvularia, two chloroplast genes, matK and rbcL, were sequenced for all five species of the genus {Uvularia floridana, U. grandifolia, U. perfoliata, U. puberula, and U. sessilifolia) and four selected members of the Liliales (Erythronium japonicum, Disporum sessile, Medeola virginiana, and Clintonia borealis). Sequence data of both matK and rbcL genes support an Uvularia which consist of two clades, section Oakesiella and section Uvularia. Though sessile-leaved and associated with section Oakesiella, U. puberula exhibits several intermediate characteristics between the sections. However, the overall molecular results correspond to an earlier sub-grouping based upon gross morphology, karyology and ecological life history traits. These two cpDNA genes, notably matK tree, proved to be informative in reaffirming relationships within Uvularia. Differentiation patterns among selected morphological, karyological and life history traits were also analyzed in comparison to the resulting molecular topologies. In comparison to the selected outgroups, Disporum sessile proved to be closely related to Uvularia in a narrowly defined Uvulariaceae — Uvulariea sensu Takhtajan (1997) or an expanded Colchicaceacae with a "uvularioid line" sense/ Nordenstam (1998). The outgroup taxa, Erythronium, Medeola, and Clintonia, associate as a well supported lineage within a narrowly defined Liliaceae. Comment is also made on the multiple origins of berry fruits in the Liliales.