Eleocharis Research
Phylogenetic relationships, classification, and patterns of photosynthetic pathway diversification in Eleocharis (Cyperaceae).
Central to the understanding of the diversification of organisms is understanding the evolution of critical physiological processes, the interaction of physiological processes and the environment, and the evolution of structure and form. Among plants, Eleocharis (Cyperaceae) is an excellent choice for studying photosynthetic pathway evolution and the associated changes in morphological and anatomical characteristics given multiple origins of C4 pathways from a C3 ancestral condition, as well as the presence of species in which individuals can utilize multiple photosynthetic pathways depending on their growing environment. Furthermore, their have been multiple adaptations to the submerged aquatic habit. Evolutionary relationships in Eleocharis are poorly understood at present, and preliminary phylogenetic evidence suggests that current classifications do not reflect evolutionary relationships in the genus.
In this project, I am collaborating with Dr. Maurice Ku (Emeritus, Washington State University) to pursue intensive studies of Eleocharis and related genera such as Chillania, Egleria, and Websteria. In particular, we are in the process of:
* generating multiple molecular phylogenies of Eleocharis and related genera using genes from the nuclear and chloroplast genomes to explore the number of C4 innovations in the genus and to compare obligate and facultative C4 and C3-C4 intermediates with their C3 progenitors or sister-species;
* studying photosynthetic pathway development including exploring the changes in stem anatomy and carbon isotope ratios associated with changes from the C3 to the C4 pathway;
* testing whether any species of Eleocharis other than E. vivipara are capable of changing photosynthetic pathway type under different growing conditions; and
* exploring morphological variation in Eleocharis in light of the molecular phylogeny.
As part of this project we are: (1) exploring phylogenetic relationships of a difficult group of angiosperms; (2) exploring in more detail the anatomical structure of photosynthetic stems in Eleocharis and their association with the classification and phylogenetic relationships in the genus; (3) providing a detailed exploration of the breadth of Eleocharis species able to change their photosynthetic pathway under different growing conditions; and (4) training undergraduate (Tim Carey and Kristina Bearden) and graduate (Cody Hinchliff) students in phylogenetic, anatomical, and biochemical research applied to systematic and evolutionary questions.