Graduation Year


Document Type




Degree Granting Department


Major Professor

Frederick B. Essig, Ph.D.

Co-Major Professor

James R. Garey, Ph.D.

Committee Member

Richard P. Wunderlin, Ph.D.


plant, molecular, DNA, clade, allele


The phylogeny of Clematis, section Viorna, was characterized in this study using molecular data. Two nuclear introns were sequenced for a variety of taxa: actin and nitrate reductase. Actin intron sequence data yielded very little phylogenetic information. Some basal clades were resolved, but there were very few well supported relationships between species of the Viorna section in both the neighbor joining and maximum parsimony analyses. Nitrate reductase intron sequence data was slightly more variable. The number of well supported relationships in both the neighbor joining and maximum parsimony analyses for nitrate reductase was greater, but still not sufficient to yield an informative tree. Two possible explanations for the lack of variation are that these species have not evolved many differences in these intron sequences or that common alleles are flowing between the species. Hybrid analysis using the actin intron was inconclusive because the experimentally generated hybrid possessed an allele that neither parents tested had. More sampling from multiple individuals from both parent and multiple hybrid individuals is necessary to answer this question. The hybrid specimen tested was homozygous for the nitrate reductase intron marker, and both parents also possessed the allele. This did not directly support or refute the use of these markers for tracking the hybridization history within Clematis.