2007 Annual Report 1a.Objectives (from AD-416) The objective of this cooperative research project is to determine the effect of transgenes from sorghum on the fitness of shattercane × sorghum hybrids. 1b.Approach (from AD-416) Sorghum with transgenes causing it to have purported increased digestibility due to over-expression of thioredoxin will be crossed to shattercane in the greenhouse using standard emasculation procedures. Hybrid progeny with and without transgenes will be evaluated to determine presence of the transgenes using DNA hybridization blots. The F1 hybrids and subsequent generations will be compared for fitness parameters including seed production, seed longevity and viability, and growth rate with and without interplant competition. 3.Progress Report This report serves to document research conducted under a Specific Cooperative Agreement between ARS and University of Nebraska-Lincoln, Department of Agronomy & Horticulture. Additional details of research can be found in the report for the parent project 5440-21220-024-00D Genetic Improvement of Sorghum for Enhancing Energy Yield, Nutrient Availability, and Disease Resistance. Prior to deployment of transgenic sorghum, it will be necessary to assess and manage the risks associated with possible transgene flow to sorghum’s weedy relatives. The objective of this cooperative research project is to determine the effect of transgenes from sorghum on the fitness of shattercane × sorghum hybrids. Transgenic sorghum lines acquired from UC Berkeley were evaluated for presence of the transgene, and fixed or homozygous lines identified for crossing with shattercane. Backcrossing of male sterility genes into shattercane to facilitate future crosses with transgenic sorghum was continued. The ADODR exchanged 50 emails with the Cooperator to monitor the project in FY07 and participates in regular meetings with a graduate student assigned to the project who is advised by the Cooperator.