ibclogo XVI International Botanical Congess


Abstract Number: 5596
Poster No. = 901


PHYLOGENETIC UTILITY OF SEQUENCE DATA FROM TWO REGIONS OF NUCLEAR DNA IN CLARIFYING SECTIONAL RELATIONSHIPS WITHIN PHYSALIS (SOLANACEAE)


Mary Kathryn Whitson & Paul Manos, Duke University, Durham, NC


To generate a resolved phylogeny of species relationships within Physalis, regions of quickly evolving DNA are needed. The introns of the GBSS (waxy) gene and the ITS region of the rDNA fit this criterion. Sequence data was gathered from ITS and an approximately 700 bp region of waxy. Sampling concentrated on species from subgenus Epeteiorhiza, which makes up the bulk of the genus. ITS sequences show more variation than waxy sequences, and also have more indels. While ITS may vary slightly within species, waxy typically does not. Gene trees from both data sets indicate that: 1) Subgenus Epeteiorhiza is not monophyletic. 2) Many of the larger sections of Epeteiorhiza are para- or polyphyletic. However, several of the rhizomatous perennial species (sections Lanceolatae and Stellatae) do cluster together. Combined analysis of the two data sets supports a monophyletic section Stellatae, in addition to providing more resolved trees with higher bootstrap support than the gene trees from either individual data set.


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