Breeding and Genetics of Miscanthus for Bioenergy

Government mandates for renewable energy and reduction of greenhouse gas emissions for fossil fuel–fired power plants have created a need for regionally adapted, high-yielding cultivars of bioenergy crops. Miscanthus is among the most promising bioenergy crops identified to date. Biomass yields of M. x giganteus are relatively high, with mature stands having the potential to exceed the yield of maize and switchgrass in the midwestern U.S. In addition, this crop exhibits remarkable sustainability through perennial growth, efficient nutrient recycling, and belowground carbon sequestration. However, Miscanthus feedstock production for the emerging U.S. bioenergy industry is based on a single sterile genotype of M. x giganteus. Developing a new crop based on a monoculture of only one genotype is risky, as the emergence of a virulent disease or insect strain could be quite damaging. Moreover, though the current M. x giganteus genotype of commerce is an excellent cultivar, there is no reason to believe that superior cultivars could not be bred by choosing better parents. There is thus a need to develop additional and improved Miscanthus cultivars, especially for the central and northern Midwest.

To meet this need, a new Miscanthus breeding and genetics programs was established at the University of Illinois within the Department of Crop Sciences and the Energy Biosciences Institute. This research program currently has the following objectives:

1. Collect and characterize Miscanthus germplasm
2. Understand evolutionary relationships among collected accessions and assess genetic diversity
3. Improve selection efficiency in field trials
4. Elucidate the genetics of key traits and identify marker-trait associations for Miscanthus

Genetic diversity is the foundation of plant improvement. It allows plant breeders to mix and match genes by crossing parents that have desirable and complementary traits, thereby obtaining improved progeny that combine the best attributes of the parents. However, few Miscanthus accessions are currently maintained in the public germplasm collections. To help solve this problem, we initiated germplasm collection expeditions in the fall of 2010, and more are planned for this fall. Studies of the collected plants have recently begun in the lab and field.

In collaboration with colleagues in Europe and Asia, we have also begun studies of Miscanthus population structure and genetic diversity. These studies will help us to identify populations where unique genes are likely to be found and to develop hypotheses about which combinations of parents have the greatest probability of producing progeny with hybrid vigor.

In the spring of 2010, we established field trials at Urbana and Dixon Springs to compare nearly all of the Miscanthus cultivars that are publicly available in the U.S. and to optimize sampling strategies to improve breeding efficiency. We have already observed large differences in overwintering ability, height, and flowering time. In addition, we are quantifying border and edge effects to determine the ideal size and configuration of plots for selection.

This year we planted seedling populations from our first crosses. The seedlings will be evaluated over the next three years, and superior types selected. Moreover, the data we take in the field and laboratory will provide knowledge about the genetics of key traits (e.g., yield, flowering time, hardiness) and to associate these traits with molecular markers, which will improve the efficiency of future breeding efforts. Overall, this work will allow us to develop improved Miscanthus cultivars and to gain knowledge on how to do so more efficiently.

Erik J. Sacks

Erik J. Sacks
Assistant Professor of Crop Sciences

Collin Reeser, Plant Breeding Research Specialist
Lindsay Clark, Postdoctoral Research Associate
Kasia Glowacka, Postdoctoral Research Associate
Chris Kaiser, Graduate Student