University of Wisconsin–Madison

Research

Ongoing projects in the Emshwiller lab include:

Origins of polyploidy and domestication of the Andean tuber crop “oca,” Oxalis tuberosa Molina

SA mapRecent results with AFLP data (Emshwiller, et al. 2009) presents a different story than earlier work with nuclear-encoded, chloroplast-expressed glutamine synthetase (ncpGS; Emshwiller and Doyle 2002). We are continuing our work on untangling the complexities of the origins of oca and clarifying its relationships with wild allies. Wild, tuber-bearing Oxalis taxa in Bolivia, Argentina, and two areas of Peru are being evaluated.

Evolution of clonally-propagated crops under human influence, the example of the Andean tuber crop Oxalis tuberosa

oca typesThis research uses “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. NSF funded via DEB 0426496 & 0732490.

 

Phylogeny and character evolution in the genus Oxalis

oxalisThe large genus Oxalis holds an amazing diversity of forms, including small shrubs, succulent herbs, long vines, and alpine cushion forms. Many have various kinds of storage structures: tubers, tuberous roots, rhizomes with fleshy scales, woody crowns, and two different kinds of bulbs. To study the evolution of plant form, we are using DNA sequences and comparisons with morphology to study the evolutionary relationships among species of Oxalis, to help understand how storage structures such as bulbs evolve, and from what precursors. The results will also shed light on the evolution of plant breeding systems, chromosome numbers, and biogeography. NSF funded via DEB 1027270.

 

oxalis structures
CT scans of bulbs and bulb-like structures in Oxalis by Andrew Gardner