My research focuses on gene discovery, the analysis of genome structure and function and the relevance of this information for the improvement of useful plants. Work in my program includes fundamental studies of the relationship between model species and less well-characterized crop species, the release of varieties and advanced breeding lines, development of improved selection strategies, and research on the genetics of disease resistance and fruit quality. Specifically, a major effort in the lab is to demonstrate the extent to which results from a leading plant model, tomato, are relevant to the related, but much less well-characterized genus, Capsicum, the garden pepper. Towards this end we have developed a detailed comparative genetic map for the Solanaceae now defining the broadest comparative genetic system in the dicots. We have used this tool to identify candidates for traits with simple and quantitative inheritance and to assess the relationships between genes in tomato and pepper that affect similar or related traits. Further studies are focusing on traits considered distinctive for a genus, e.g., pungency. Finally, the Solanaceae have afforded a unique glimpse of the organization of resistance genes in plant genomes. We have shown that despite co-evolutionary forces in host/pathogen interactions, disease resistance genes represent ancient lineages in plants and that resistance pathways may be very highly conserved. We also have extensive gene discovery and breeding activities that integrate classical and molecular methods for generating and selecting desirable genetic variability, primarily focused on the identification of new sources of biotic and abiotic stress resistance from wild accessions and related species in cucurbits, Phaseolus and pepper. I also direct the Public Seed Initiative, an outreach activity based on an alliance of public sector researchers and non-profit groups interested in improving the dissemination and utilization of public plant varieties and crop genetic diversity.

[ Dr. Jahn is currently the Dean of the College of Agriculture and Life Sciences at the University of Wisconsin ]