University Team Studies Sorghum Genetics To Fuel Green Energy Research

MANHATTAN -- Those choices at the pump may look a little greener in the future as a Kansas State University research team is conducting a study that could eventually add "plant" to the list of fuel options.

In early August, four faculty members from K-State's College of Agriculture and College of Engineering received an $800,000 grant from the U.S. departments of Agriculture and Energy under the Plant Feedstocks Genomics for Bioenergy research program. The grant funds a three-year study that will provide the genetic groundwork necessary for potentially turning sorghum into biofuel by increasing the plant's biomass yield.

"Bioenergy is a very hot topic and there's a lot of talk about its possibilities," said Jianming Yu, associate professor of agronomy and leader of the study. "But a lot of work still needs to be done since it's still a new field. And unless genetics is improved, industries probably won't want to get involved because there are still too many unknowns."

Yu is conducting the sorghum bioenergy study with K-State's Tesfaye Tesso, assistant professor of agronomy; Scott Staggenborg, professor of agronomy; and Donghai Wang, professor of biological and agricultural engineering, along with researchers from the University of Minnesota and the USDA's Agricultural Research Service plant genetic resources conservation unit. K-State is one of nine universities chosen nationally to participate in genomics studies related to bioenergy. Potential benefits from these university studies range from decreasing oil imports to optimizing crops that can tolerate drought, poor soil and other unfavorable conditions.

Over the next three years the K-State team will build a genetic database on biomass sorghum, a type of sorghum that contains little grain and is mostly leaves and stalk. Biomass sorghum provides a large amount of high-quality feedstock, which can produce eco-friendly fuels. Kansas is the top producer of sorghum in the U.S., accounting for nearly half of the country's annual yield. Similarly, the U.S. is the world's largest grain sorghum exporter and ranks second in production, according to Staggenborg.

But despite the country's large production of sorghum, little data about biomass sorghum's genetics and how to improve the crop exists, outside of some USDA studies on the sorghum collection conducted many years ago. While many grain crops have had their genetics and production refined and documented for decades, the K-State sorghum team essentially has to start from scratch.

"Our study will sort of be a prototype with new lessons and insights into how we combine this proven method of plant breeding -- changing a plant's genetics to make more starch, more yield, or in this case, more biomass -- with this new genomic technology to optimize the improvement process," Tesso said. "In the bigger picture, this study addresses some of those emerging issues with energy and climate change."

To build the database, the team is looking at genetic diversity in sorghum's germplasm -- essentially the plant's gene bank. Members will start with 1,000 sorghum lines selected from the center of the germplasm pool. A line is the unique genetic material in sorghum. Those samples will then be genotyped, a process where the team looks at each sample's unique molecular diversity and compares it to the molecular diversity found in the sampled collection as a whole.

From those 1,000 samples, a subset of 300 samples will be chosen to represent the maximum amount of diversity, and will be studied more in depth for biomass yield and biomass composition. Once the biomass yield is found for those 300 samples, Yu and the others can then predict the biomass yield of the remaining 700 untested samples from that original 1,000 sample set.

Additionally, some field samples will chemically analyzed. Data from this analysis will be used with near-infrared spectroscopy technology to build predictive models. The researchers can use these models to accurately predict the biomass composition in the other samples rather than using the costly chemical analysis process. Wang, whose expertise is in biological and agricultural engineering, will oversee this phase.

"This process is part of what we call 21st-century predictive biology," Yu said. "We'll have a total of 3,600 field samples collected for this two-year, dual replication study from three locations in Kansas. The third and final year will be dedicated to validation. Basically we'll have a ton of samples to work with, and this predictive process will help us manage the data and workload."

Yu said the group is prepped for this new genetic challenge through their previous research projects, which have been supported by K-State's Targeted Excellence Program, Kansas Grain Sorghum Commission, National Sorghum Checkoff Program and the Great Plains Sorghum Improvement and Utilization Center.

"There's that adage that says you can't just build a better car by making a bigger engine. You also need a solid frame to support it," Yu said. "For this biomass sorghum car, we don't have the upgrades yet that are necessary to really think about the engine, so we need to build and improve that framework. It's pretty exciting that a single project like this can bring together such an interdisciplinary team for a singular focus."