2007 Annual Report 1a.Objectives (from AD-416) Identify unique genes involved in the response of dry bean (Phaseolus vulgaris) to infection by Sclerotinia sclerotiorum. 1b.Approach (from AD-416) Two inbred backcross dry bean mapping populations will be used. A QTL mapping study will be conducted on both populations using field and greenhouse phenotypic data and simple sequence repeat molecular marker data collected on individual inbred backcross lines. Upon development of a linkage map for each population and identification of QTL for white mold resistance, the underlying function of the genes involved in resistance will be studied using a cDNA-AFLP approach. 3.Progress Report This report documents research conducted under a specific cooperative agreement between ARS and Michigan State University. Additional details of research can be found in the report for the in-house associated project 5442-21220-023-00D, “Sclerotinia Diseases.” This project was initiated on June 1, 2005, and research is ongoing. The overall objective is to identify resistance genes important in plant defense responses of dry beans to Sclerotinia. Two inbred backcross populations with a common recurrent parent serve as the basis for the quantitative trait loci (QTL) study that is part of the funded work. During the past year, a fourth season of field data was collected on a subset of the lines from each population for reaction to white mold at the Montcalm Research Farm in Entrican, Michigan. Both populations were also evaluated in the greenhouse for resistance to white mold using the straw test. Genotypic data collection on all lines from both populations was completed and linkage maps were developed for both populations. QTL analyses were conducted for the mapping populations which identified significant QTL for both the greenhouse screening and from the field based white mold nursery. The results of the QTL analysis for one of the mapping populations were presented at the 2007 National Sclerotinia Initiative annual meeting. Two resistant and two susceptible lines from one of the mapping populations were selected for transcript level analysis using cDNA-AFLP. RNA was collected from inoculated and mock inoculated plants and screened with AFLP markers to identify fragments, representing transcribed genes, which are differentially expressed between lines or treatments. Such fragments have been identified and sequence analysis is currently underway. ADODR monitoring activities to evaluate research progress included phone calls, meetings with the cooperator, and an annual meeting held each year in January. Publications: Ender, M., K. Terpstra and J. D. Kelly. 2007. Marker-assisted selection for white mold resistance in common bean. Mol. Breed. (on line:10.1007/s11032-007-9115-9).