Expanding the Breeder's Toolbox: Use of the Model Perennial Grass Brachypodium sylvaticum to Study Abiotic Stress and to Develop Biotechnological Tools for Switchgrass Improvement

There is a great need for the development of alternative and sustainable fuel sources, and switchgrass is poised to become one of the first dedicated biomass crops due to its inherent high yield, C₄ metabolism, and perennial nature. We are using a systems biology approach and the model perennial grass Brachypodium sylvaticum to develop biotechnological tools for switchgrass improvement. Research evaluating the ability of a suite of candidate transgenes to improve plant stress tolerance and/or efficient water and nutrient use is being conducted. Transgenes shown to improve stress tolerance in B. sylvaticum, will be selected for engineering improved switchgrass. This approach can rapidly introduce these desirable characteristics into different cultivars allowing breeders to incorporate these traits into elite germplasm. In addition, the development of a method to generate double haploid plants is also being pursued. Having homozygous lines available for breeding will overcome the barrier of self incompatibility and greatly facilitate switchgrass cultivar development. Finally, since biotechnologically improved switchgrass will ultimately be grown in open fields, they must be designed to minimize the potential impact of the transgenes on non-target ecosystems. Thus we are developing a strategy to minimize transgene flow from the genetically engineered crop by ablating the transgenic pollen, thus reducing the transmission of transgenes in the environment.