Phylogeny of the Batrachospermales (Rhodophyta, Red Algae)

Ohio University, Athens OH

Investigators

Abstract

0235676 Vis-Chiasson In the red algae, molecular DNA sequence data have challenged traditional morphologically based theories of relatedness. The order of freshwater red algae, Batrachospermales, is no exception; and at present, evolutionary relationships among genera and species of this order are not well understood. To compound the problem, knowledge of the flora in most of the southern hemisphere is very poor. The object of this project is to produce a robust molecular framework as the foundation for future taxonomic revision in this group of algae. Collection of specimens will focus on potential "hot spots" of diversity in New Zealand, Tasmania, Northern Brazil, Malaysia and South Africa. Two gene regions will be sequenced from the taxa to ensure abundant molecular data. The combination of new DNA sequence data and more taxa will result in a well-resolved framework of relationships. This study of freshwater red algae is timely given that molecular evolution studies of marine red algae are underway, to which this research will dovetail. Although the field research is localized, the results will tie together information from five continents (North America, South America, Africa, Asia and Australia) for an integrated understanding of the biogeography of a group of freshwater algae. Freshwater red algae are important biological components of stream ecosystems worldwide, serving as food and shelter for numerous aquatic insects and fish. The Batrachospermales tend to occur in streams that have had little anthropogenic disturbance and can be an indicator of good water quality. Our ability to use them as biological indicators is hampered by our lack of knowledge of their systematics. For example, a Batrachospermum species defined by morphological characteristics was thought to be cosmopolitan, occurring in a wide range of streams, but recent molecular research has shown that the organisms from Australia that were attributed to this species were in fact endemic to that region, and a new species unrelated to the North American species was described. Knowing this information, the geographic and ecological range of each species has been refined. In addition to the new knowledge produced, graduate students and undergraduate students will benefit from participation in this research. The students will participate in the collecting trips to other parts of the world. They will interact with in-country colleagues gaining not only field experience but also an appreciation for the science and culture of that country. The laboratory research the students conduct will result in presentations at scientific meetings by the students and peer-reviewed publications. At the end of their studies, the undergraduates will be fully prepared to pursue research in graduate school and the graduate students will be highly trained professionals ready for a career in academia or industry.