Understanding how species coexist, and the role of genetic diversity within and between species, remains a fundamental challenge in biodiversity research. This project focuses on highly diverse communities of clover plants and their bacterial nitrogen-fixing symbionts, rhizobia. Integrating observational approaches, manipulative field, greenhouse, and growth chamber experiments, genomic techniques and phylogenetic analyses, this project will test the importance of rhizobial symbionts and soil feedbacks in coexistence. Gene expression and functional traits will serve as proxies for the ecological niche; this project will determine how these evolve using phylogenetic trees that capture the evolutionary history of species. This project will yield an integrated insight into the molecular, functional, and ecological mechanisms of diversity maintenance and will greatly increase our understanding of biological nitrogen fixation, a critical function of legumes and rhizobia in natural and agricultural ecosystems.
Symbiotic nitrogen fixation has global importance on par with photosynthesis, and this project will assess its functionality in light of genetic variation in symbionts and clover species. This project will train two post-docs and two graduate students and will provide research experiences to undergraduate students through the Plant Genomics at MSU program, and through an exchange program with Howard University at UC Davis. The project will train students in the High School Honors Science Program at MSU and in the Ecological Society of America?s SEEDS program (Strategies for Ecology Education, Diversity and Sustainability: Diverse People for a Diverse Science).