Molecular and Morphological Studies of Evolution in the Gelidiales (Rhodophyta)

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9726170 Freshwater The red algal order Gelidiales contains many economically important species; gelidialean algae are a principal source of agar, widely used in the food and cosmetics industry and in microbiological, biochemical and genetics research. However, the group as a whole, and species within it, have been difficult to identify and classify. Traditional classifications of red algae, including the Gelidiales, have been based on particular life history types, and characteristics of the developmental morphology of the female reproductive system. Developmental characteristics of the female reproductive system and related stages in the life history are thought to be useful in classifications of red algae, because changes in these characters would prevent cross-breeding between changed and unchanged algal populations (reproductive isolation), leading to the formation of species and, ultimately, lineages of species (clades). Independent data are needed to test the idea that these reproductive characters are useful in classification, and also are needed to provide a means of classifying algae for which, as in many Gelidiales, information from reproductive systems is hard to obtain or interpret. In this study, D. Wilson Freshwater will document the vegetative morphology and reproductive strategies of key gelidialean taxa, and will reconstruct the phylogenetic history of these taxa on the basis of both these characters and DNA sequence data from several nuclear and plastid genes. The work is expected to result in a robust reconstruction of the phylogenetic history of the Gelidiales and evaluate the utility of life history and reproductive characters in reconstructing this history, in Gelidiales and in other red algae.