Vegetatively-propagated crops play an enormous role in feeding the world, but we understand poorly how they differ from seed-propagated crops in their evolution and needs for conservation. Little is known about how clonal growth interacts with selection and dispersal of crops by humans to influence plant domestication and crop evolution. This research uses the Andean tuber crop "oca," Oxalis tuberosa, to study how human exchange networks distribute clones of the crop geographically and how they affect clonal diversity in traditional subsistence agriculture. Specifically, this project compares the diversity of oca among different localities and to other clonal plants, and uses spatial statistics to analyze patterns of clonal and genetic structure of oca across the Peruvian Andes. DNA fingerprinting (fluorescent AFLP) distinguishes whether similar-looking tubers are genetic clones. The same kind of data also compares oca to wild Oxalis species to test hypotheses (based on previous DNA sequence data) about the origins of oca's multiple chromosome sets (polyploidy).
Training workshops and involvement of Peruvian students in the research will build international capacity for protecting the rich agricultural biodiversity of the Andean region. To improve access to information, results will be disseminated, in both English and Spanish, in scientific papers and presentations as well as in non-technical publications. Collaboration between The Field Museum, Michigan State University, and the International Potato Center in Lima, Peru, reciprocally builds institutional capacity. Societal benefits include improving strategies to conserve the diversity of clonal crops and increasing understanding of their domestication. Because so little is known about clonal distributions of any crop in traditional agriculture, the results will not only be important to conserve oca's diversity, but will improve our understanding of the human influence on other vegetatively-propagated crops.
