Accelerating the Domestication of Miscanthus for Biofuel Production. University of Georgia, Athens, $1,200,000.

Expansion of agriculture to provide plant biomass for production of fuels and/or feedstocks will require additions to the present repertoire of crops. The Saccharinae clade of tropical grasses is of singular importance, including Miscanthus, among the highest-yielding of biomass crops. Its adaptability to continental Europe shows the feasibility of producing Miscanthus in temperate latitudes. Scientific breeding of Miscanthus is only beginning, and many early priorities are “domestication traits” about which there exists much information in sorghum and/or sugarcane and for which the locations of controlling genes/QTLs (quantitative trait loci) often correspond across divergent grasses.

The objectives of this proposal are (1) to jump-start Miscanthus improvement by empirically testing whether previously mapped genes/QTLs from sorghum and other cereals are diagnostic of key Miscanthus traits and (2) to improve knowledge of Miscanthus genome organization.

The Hunt for Green Every April: Factors Affecting Fitness in Switchgrass. USDA-ARS-Lincoln, $1,182,000.

Perennial biomass energy crops such as switchgrass have significant net energy advantages because annual planting each spring is not required and they can be grown on marginal cropland. Switchgrass plants need to survive both repeated harvests and winters in the production fields for 10 or more years. Winter hardiness and survival are therefore critical traits. However, the physiological and genetic factors underlying perenniality and winter hardiness (fitness) in perennial grasses such as switchgrass are not known.

This grant seeks to understand winter survival in switchgrass populations and individual plants specifically selected for greater yields and with known differences in winter survival by studying molecular events occurring in the crowns and rhizomes during two growing seasons and winters.

The objectives of this proposal are (1) To utilize novel genomic and biochemical tools to investigate molecular mechanisms underpinning nutrient partitioning and remobilization in crowns and rhizomes of switchgrass cultivars with divergent winter hardiness. (2) To use high-throughput DNA sequencing to query transcript abundance (levels of gene expression) in specific populations of switchgrass plants during regreening and dormancy. (3) To study the genetic variation (extent of linkage disequilibrium in populations) and eventually develop genetic markers for cold-adaptation and fitness traits in switchgrass plants being developed for the Central and Northern United States that show significant hybrid vigor (heterosis).

Phenomic Analysis of Natural and Induced Variation in Brachypodium distachyon. USDA-ARS Western Regional Research Center, Albany, California, $1,300,000.

Herbaceous energy crops, especially grasses, are poised to become a major source of energy in the United States. Despite their increasing importance, we know little about the basic biology underlying the traits that control the utility of grasses as energy crops. Better knowledge of basic grass biology (e.g., identification of the genes that control cell-wall composition, plant architecture, cell size, cell division, reproduction, nutrient uptake, carbon flux, etc.) could be used to design rational strategies for crop improvement and shorten the time required to domesticate these new crops. This project proposes to conduct high-throughput phenotypic analysis (phenomics) of homozygous T-DNA mutants and natural accessions of the model grass Brachypodium distachyon (Brachypodium) to accelerate the acquisition of this knowledge.

Objectives of the work are to (1) Assemble a collection of natural accessions and 2,000 homozygous T-DNA lines. (2) Conduct a detailed phenotypic characterization of the collection using a phenomic approach. (3) Begin detailed characterization of a select group of mutants and natural accessions.

Mechanism of Carbon Partitioning Regulation by cpg13 in the Bioenergy Woody Crop Poplar. University of Florida, $643,000.

Plant biomass is composed primarily of cellulose, lignin, and hemicellulose. The lignin content of biomass limits bioconversion of wood cellulosics to renewable biofuels by decreasing the available amount of carbohydrate and by hindering cellulose degradation. High lignin content also negatively impacts biomass productivity in several woody species. Therefore, characterizing genes that regulate the balance of carbon going to cellulosics or lignin can lead to the development of plant materials that are more suitable for biofuel production. The researchers in this project recently identified a previously uncharacterized gene, cpg13 (carbon partitioning and growth in chromosome 13), as a key regulator of carbon partitioning to lignin and cellulose and of biomass productivity in Populus.

The researchers hypothesize that cpg13 regulates the metabolic competition for carbon, affecting growth, cellulose biosynthesis, and lignification. This project will identify the molecular role of cpg13 by (1) characterizing its function in the regulation of gene expression, metabolites, and cell wall chemistry and structure and by (2) determining its spatial and temporal expression and subcellular localization.

A Systems Biology Approach to Elucidate Regulation of Root Development in Populus. Michigan Technological University, $900,000.

This project will identify key regulators of root architecture in relation to nitrogen and water use in the bioenergy crop Populus using an integrated systems biology approach. This research will generate resources and innovations that can enable robust biomass productivity under marginal conditions for sustainable lignocellulosic biomass production.

Improving Alfalfa as a Biofuel Feedstock. University of Georgia, Athens, $705,000.

Alfalfa, widely grown in the United States as a hay crop, can also be used for bioenergy. At harvest, alfalfa leaves would be removed as a high-protein animal feed, leaving less nutritious stems to be used for energy production. Biofuel crops must maximize the production of energy, which requires high yields of biomass with optimum fuel quality. The long-term goal of the project is to develop alfalfa biofuel-ready cultivars that have improved yield and quality.

To reach that goal, this project specifically seeks (1) to develop genetic markers in genes that may control biomass composition and yield, (2) to screen alfalfa plants with the markers to identify the genetic variants that each plant possesses, and (3) to associate those markers with yield and cell-wall composition measured on the same plants that were grown in the field.

Characterization of Nitrogen Use Efficiency in Sweet Sorghum. University of Nebraska, Lincoln, $390,000.

Enhancing the ability of sweet sorghum to utilize nitrogen will increase its potential as a leading and cost-effective bioenergy crop. This project will identify novel nitrogen use efficiency alleles in wild sorghum germplasm that can be used to improve sweet sorghum.