Becky Oldham

Department of Botany

430 Lincoln Drive

University of Wisconsin

Madison, WI 53706-1381

Office: 244 Birge Hall
Phone: (608) 262-2743

Fax: (608) 262-7509
Email: oldhamhaltom@wisc.edu

Educational Background:

BS in Biology and Environmental Studies, Manchester College, Indiana, 1999

Masters of Science in Biodiversity and Taxonomy of Plants, University of Edinburgh and the Royal Botanic Gardens, Edinburgh, Scotland, 2000

Research Interests:

Floral evolution and development

Hobbies:

Horseback riding, sailing, running, gardening, salsa-dancing

Current Projects:

Evolution of the epicalyx in Pavonia (Malvaceae)

I am studying the evolution of the epicalyx in Malvaceae, and my project is divided into 2 broad categories.

(1) In Malvales, the epicalyx is typically comprised of 3 leaf-like organs located below the sepals. The epicalyx of most taxa in Malvaceae appears to be incorporated into the flower as a fifth whorl. Is there a fifth whorl in these flowers? If so, how did the epicalyx acquire a “whorl identity”? I will characterize this transition developmentally through SEM studies of taxa with different types of epicalyces.

(2) In some taxa, the epicalyx is large and colorful while the petals and sepals are reduced; thus, the role of pollinator attraction is most likely to have been transferred from the petals to the epicalyx. I will determine whether there are multiple independent origins of the petaloid epicalyx by generating a skeleton molecular phylogeny of the genus Pavonia, which contains the most taxa with petaloid epicalyces. I will investigate genes that are expressed in the epicalyx that may be involved in the transition to petaloidy using the B-class genes as candidates.

In order to do this, I will first look for evidence that the ABC+ model is conserved in Malvaceae. If it is (and my preliminary results suggest that it is conserved), then through rt-PCR and in-situ hybridization I will determine which genes are expressed in which whorls. If B-class expression has expanded into the epicalyx, this could be responsible for the petal-like characteristics.

Once I identify the genes involved in conferring petal-like characteristics to the epicalyx, I will determine whether the same mechanisms are used in the transition from a non-showy to a petaloid epicalyx among taxa with independent origins of the petaloid epicalyx by comparing these genes and their expression patterns.

Two views of the flower of Pavonia multiflora