title: Energy sorghum--a genetic model for the design of C4 grass bioenergy crops.
abstract: Sorghum is emerging as an excellent genetic model for the design of C4 grass bioenergy crops. Annual energy Sorghum hybrids also serve as a source of biomass for bioenergy production. Elucidation of Sorghum's flowering time gene regulatory network, and identification of complementary alleles for photoperiod sensitivity, enabled large-scale generation of energy Sorghum hybrids for testing and commercial use. Energy Sorghum hybrids with long vegetative growth phases were found to accumulate more than twice as much biomass as grain Sorghum, owing to extended growing seasons, greater light interception, and higher radiation use efficiency. High biomass yield, efficient nitrogen recycling, and preferential accumulation of stem biomass with low nitrogen content contributed to energy Sorghum's elevated nitrogen use efficiency. Sorghum's integrated genetics-genomics-breeding platform, diverse germplasm, and the opportunity for annual testing of new genetic designs in controlled environments and in multiple field locations is aiding fundamental discovery, and accelerating the improvement of biomass yield and optimization of composition for biofuels production. Recent advances in wide hybridization between Sorghum and other C4 grasses could allow the deployment of improved genetic designs of annual energy Sorghums in the form of wide-hybrid perennial crops. The current trajectory of energy Sorghum genetic improvement indicates that it will be possible to sustainably produce biofuels from C4 grass bioenergy crops that are cost competitive with petroleum-based transportation fuels.
authors: Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77845-2128, USA jmullet@tamu.edu.
authors: John
authors: J
authors: Mullet
authors: Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77845-2128, USA.
authors: Daryl
authors: D
authors: Morishige
authors: Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77845-2128, USA.
authors: Ryan
authors: R
authors: McCormick
authors: Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77845-2128, USA.
authors: Sandra
authors: S
authors: Truong
authors: Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77845-2128, USA.
authors: Josie
authors: J
authors: Hilley
authors: Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77845-2128, USA.
authors: Brian
authors: B
authors: McKinley
authors: Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77845-2128, USA.
authors: Robert
authors: R
authors: Anderson
authors: Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77845-2128, USA.
authors: Sara N
authors: SN
authors: Olson
authors: Department of Soil and Crop Science, Texas A&M University, College Station, Texas 77845-2128, USA.
authors: William
authors: W
authors: Rooney
mesh_terms: D056804:Biofuels; D018533:Biomass; D001947:Breeding; D018556:Crops, Agricultural; D004734:Energy Metabolism; D035264:Flowers / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D018745:Genome, Plant / Q000235:genetics*; D023281:Genomics; D010641:Phenotype; D010802:Phylogeny; D006109:Poaceae / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D045868:Sorghum / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects; D013997:Time Factors
chemical_list: D056804:Biofuels
keywords: Biomass yield; C4 grass; energy Sorghum; flowering time; genomics; traits.