Developing Switchgrass for Biomass Production: Community Gardens Help Distinguish Genetic Bases of Fitness Traits from Climatic Influence

The Science

Investigate the genetic basis of local adaptation in order to increase biomass yield for sustainable biofuel production.

  • Established switchgrass community gardens in 10 different field sites in United States.
  • Developed and clonally propagated >400 lowland x upland hybrids.
  • Samples collected for sequencing and analysis at all sites over two full years.
  • QTL mapping applied to investigate genes involved in key fitness traits, and how these genes interact with the environment.

The Impact

  • Spring emergence and flowering time determined by location.
  • Fewer tradeoffs than expected found in genetic contribution to local adaptation across geographic range.
  • Large-scale field experiment demonstrates potential for development of “generalist” switchgrass by combining locally advantageous alleles.

Summary

Local adaptation is the process by which natural selection drives adaptive phenotypic divergence across environmental gradients. This study demonstrates that most loci underlying locally adaptive trait variation have beneficial effects in some geographic regions while conferring little or no detectable cost in other parts of the geographic range of switchgrass over two field seasons of study. Thus, loci that contribute to local adaptation vary in the degree to which they are costly in alternative environments but typically confer greater benefits than costs. Further, this study suggests that breeding locally adapted varieties of switchgrass will be a boon to the biofuel industry, as locally adaptive loci could be combined to increase local yields in switchgrass.

BER Program Manager

Shing Kwok

U.S. Department of Energy, Biological and Environmental Research (SC-33)
Biological Systems Science Division
[email protected]

References

Lowry, D. B., J. T. Lovell, L. Zhang, J. Bonnette, P. A. Fay, R. B. Mitchell, J, Lloyd-Reilly, A. R. Boe, Y. Wu, F. M. Rouquette Jr., R. L. Wynia, X. Weng, K. D. Behrman, A. Healey, K. Barry, A. Lipzen, D. Bauer, A. Sharma, J. Jenkins, J. Schmutz, F. B. Fritschi, and T. E. Juenger. 2019. “QTL × Environment Interactions Underlie Adaptive Divergence in Switchgrass Across a Large Latitudinal Gradient,” Proceedings of the National Academy of Sciences USA 116(26), 12933–941. DOI:10.1073/pnas.1821543116.