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Opportunities and roadblocks in utilizing forages and small grains for liquid fuels

  • Gautam Sarath
  • Robert B. Mitchell
  • Scott E. Sattler
  • Deanna Funnell
  • Jeffery F. Pedersen
  • Robert A. Graybosch
  • Kenneth P. Vogel
Review

Abstract

This review focuses on the potential advantages and disadvantages of forages such as switchgrass (Panicum virgatum), and two small grains: sorghum (Sorghumbicolor), and wheat (Triticum aesitvum), as feedstocks for biofuels. It highlights the synergy provided by applying what is known from forage digestibility and wheat and sorghum starch properties studies to the biofuels sector. Opportunities therefore, exist to improve biofuel qualities in these crops via genetics and agronomics. In contrast to cereal crops, switchgrass still retains tremendous exploitable genetic diversity, and can be specifically improved to fit a particular agronomic, management, and conversion platform. Combined with emerging studies on switchgrass genomics, conversion properties and management, the future for genetic modification of this species through conventional and molecular breeding strategies appear to be bright. The presence of brown-midrib mutations in sorghum that alter cell wall composition by reducing lignin and other attributes indicate that sorghum could serve as an important model species for C4-grasses. Utilization of the brown-midrib traits could lead to the development of forage and sweet sorghums as novel biomass crops. Additionally, wheat crop residue, and wheat and sorghum with improved starch content and composition represent alternate biofuel sources. However, the use of wheat starch as a biofuel is unlikely but its value as a model to study starch properties on biofuel yields holds significant promise.

Keywords

Biofuels Forage digestibility Sorghum Switchgrass Wheat 

Notes

Acknowledgments

We thank Dr. Lisa M. Baird (University of San Diego) for the scanning electron micrographs of switchgrass internodes. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the US Department of Agriculture.

References

  1. 1.
    Akin DE, Hanna WW, Rigsby LL (1986a) Normal-12 and brown midrib-12 sorghum. I. Variations in tissue digestibility. Agron J 78:827–831CrossRefGoogle Scholar
  2. 2.
    Akin DE, Hanna WW, Snook ME, Himmelsbach DS, Barton FEI, Windham WR (1986b) Normal-12 and brown midrib-12 sorghum. II. Chemical variations and digestibility. Agron J 78:832–837CrossRefGoogle Scholar
  3. 3.
    Adler PR, Sanderson MA, Boateng AA, Weimer PJ, Jung H-JG (2006) Biomass yield and biofuel quality of switchgrass harvested in fall or spring. Agron J 98:1518–1525CrossRefGoogle Scholar
  4. 4.
    Barton FE 2nd, Windham WR (1988) Determination of acid-detergent fiber and crude protein in forages by near-infrared reflectance spectroscopy: collaborative study. J Assoc Off Anal Chem 71:1162–1167PubMedGoogle Scholar
  5. 5.
    Bittinger TS, Cantrell RP, Axtell JD (1981) Allelism tests of the brown midrib mutants of Sorghum. J Hered 72:147–148CrossRefGoogle Scholar
  6. 6.
    Barrière Y, Ralph J, Mechin V, Guillaumie S, Grabber JH, Argillier O, Chabbert B, Lapierre C (2004) Genetic and molecular basis of grass cell wall biosynthesis and degradability. II. Lessons from brown-midrib mutants. C R Biol 327:847–860PubMedCrossRefGoogle Scholar
  7. 7.
    Boerjan W, Ralph J, Baucher M (2003) Lignin biosynthesis. Annu Rev Plant Biol 54:519–46PubMedCrossRefGoogle Scholar
  8. 8.
    Bout S, Vermerris W (2003) A candidate-gene approach to clone the sorghum Brown midrib gene encoding caffeic acid O-methyltransferase. Mol Genet Genomics 269:205–14PubMedGoogle Scholar
  9. 9.
    Bouton JH (2004) Improving switchgrass as a bioenergy crop for the Southeastern USA. Proc Am Forage Grass Council 13:348–351Google Scholar
  10. 10.
    Bucholtz DL, Cantrell RP, Axtell JD, Lechtenberg VL (1980) Lignin biochemistry of normal and brown midrib mutant sorghum. J Agric Food Chem 28:1239–1245CrossRefGoogle Scholar
  11. 11.
    Casler MD, Boe AR (2003) Cultivar × environment interactions in switchgrass. Crop Sci 43:2226–2233CrossRefGoogle Scholar
  12. 12.
    Casler MD, Buxton DR, Vogel KP (2002) Genetic modification of lignin concentration affects fitness of perennial herbaceous plants. Theor Appl Genet 104:127–131PubMedCrossRefGoogle Scholar
  13. 13.
    Casler MD, Jung HJG (2006) Relationships of fibre, lignin, and phenolics to in vitro fibre digestibility in three perennial grasses. Anim Feed Sci Technol 125:151–161CrossRefGoogle Scholar
  14. 14.
    Casler MD, Vogel KP (1999) Accomplishments and impact from breeding for increased forage nutritional value. Crop Sci 39:12–20CrossRefGoogle Scholar
  15. 15.
    Casler MD, Vogel KP, Taliaferro CM, Wynia RL (2004) Latitudinal adaptation of switchgrass populations. Crop Sci 44:293–303CrossRefGoogle Scholar
  16. 16.
    Cassman KG, Liska AJ (2007) Food and fuel for all: realistic or foolish? Biofuel Bioprod Bioref 1:18–23CrossRefGoogle Scholar
  17. 17.
    Chen F, Dixon RA (2007) Lignin modification improves fermentable sugar yields for biofuel production. Nat Biotechnol 25:759–761PubMedCrossRefGoogle Scholar
  18. 18.
    Chen F, Srinivasa Reddy MS, Temple S, Jackson L, Shadle G, Dixon RA (2006) Multi-site genetic modulation of monolignol biosynthesis suggests new routes for formation of syringyl lignin and wall-bound ferulic acid in alfalfa (Medicago sativa L.). Plant J 48:113–124PubMedCrossRefGoogle Scholar
  19. 19.
    Cherney JH, Axtell JD, Hassen MM, Anliker KS (1988) Forage quality characterization of a chemically induced brown-midrib mutant in pearl millet. Crop Sci 28:783–778CrossRefGoogle Scholar
  20. 20.
    Cherney JH, Cherney DJR, Akin DE, Axtell JD (1991) Potential of brown-midrib, low-lignin mutants for improving forage quality. Adv Agron 46:157–198CrossRefGoogle Scholar
  21. 21.
    Cosgrove DJ (2005) Growth of the plant cell wall. Nat Rev Mol Cell Biol 6:850–861PubMedCrossRefGoogle Scholar
  22. 22.
    Das MK, Fuentes RG, Taliaferro CM (2004) Genetic variability and trait relationships in switchgrass. Crop Sci 44:443–448CrossRefGoogle Scholar
  23. 23.
    Das Neves M, Shimizu AN, Kimura T, Shiiba K (2007) Kinetics of bioethanol production from wheat milling by-products. J Food Process Eng 30:338–356CrossRefGoogle Scholar
  24. 24.
    Degenhart NR, Werner BK, Burton GW (1995) Forage yield and quality of a brown mid-rib mutant in pearl millet. Crop Sci 35:986–988CrossRefGoogle Scholar
  25. 25.
    Dien BS, Iten LB, Skory CD (2005) Converting herbaceous energy crops to bioethanol: a review with emphasis on pretreatment processes, In: Hou CT (ed), Handbook of Industrial biocatalysis, Taylor and Francis, Boca Raton, Fl, Chapter 23Google Scholar
  26. 26.
    Dien BS, Jung HG, Vogel KP, Casler MD, Lamb JFS, Weimer PJ, Iten L, Mitchell RB, Sarath G (2006) Chemical composition and response to dilute-acid pretreatment and enzymatic saccharification of alfalfa, reed canarygrass, and switchgrass. Biomass Bioenergy 30:880–891CrossRefGoogle Scholar
  27. 27.
    Dixon RA, Chen F, Guo D, Parvathi K (2001) The biosynthesis of monolignols: a “metabolic grid”, or independent pathways to guaiacyl and syringyl units? Phytochemistry 57:1069–1084PubMedCrossRefGoogle Scholar
  28. 28.
    FAO (2006) Food outlook: Global market analysis. (ftp://ftp.fao.org/docrep/fao/009/j8126e/j8126e00.pdf)
  29. 29.
    Farrell AE, Plevin RJ, Turner BT, Jones AD, O’Hare M, Kammen DM (2006) Ethanol can contribute to energy and environmental goals. Science 311:506–508PubMedCrossRefGoogle Scholar
  30. 30.
    Frank AB, Berdahl JD, Hanson JD, Liebig MA, Johnson HA (2004) Biomass and carbon partitioning in switchgrass. Crop Sci 44:1391–1396CrossRefGoogle Scholar
  31. 31.
    Fritz JO, Moore KJ, Jaster EH (1990) Digestion kinetics and cell wall composition of brown midrib sorghum × sudangrass morphological components. Crop Sci 30:213–219CrossRefGoogle Scholar
  32. 32.
    Funnell DL, Pedersen JF (2006) Reaction of sorghum lines genetically modified for reduced lignin content to infection by Fusarium and Alternaria spp. Plant Dis 90:331–388CrossRefGoogle Scholar
  33. 33.
    Gerhardt RL, Fritz JO, Moore KJ, Jaster EH (1994) Digestion kinetics and composition of normal and brown midrib sorghum morphological components. Crop Sci 34:1353–1361CrossRefGoogle Scholar
  34. 34.
    Grabber JH, Jung GA, Hill RRJr (1991) Chemical composition of parenchyma and sclerenchyma cell walls isolated from orchardgrass and switchgrass. Crop Sci 31:1058–1065CrossRefGoogle Scholar
  35. 35.
    Graybosch RA, Guo G, SheltonDR (2000) Aberrant falling numbers of waxy wheats independent of alpha-amylase activity. Cereal Chem 77:1–3CrossRefGoogle Scholar
  36. 36.
    Guillaumie S, Pichon M, Martinant JP, Bosio M, Goffner D, Barriere Y (2007) Differential expression of phenylpropanoid and related genes in brown-midrib bm1, bm2, bm3, and bm4 young near-isogenic maize plants. Planta 226:235–250PubMedCrossRefGoogle Scholar
  37. 37.
    Gupta SC (1995) Allelic relationships and inheritance of brown midrib trait in sorghum. J Hered 86:72–74CrossRefGoogle Scholar
  38. 38.
    Hanna WW, Monson WG, Gaines TP (1981) IVDMD, total sugars, and lignin measurements on normal and brown midrib (bmr) sorghums at various stages of development. Agron J 73:1050–1052CrossRefGoogle Scholar
  39. 39.
    Hill J, Nelson E, Tilman D, Polasky S, Tiffany D (2006) From the Cover: Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels. Proc Natl Acad Sci USA 103:11206–11210PubMedPubMedCentralCrossRefGoogle Scholar
  40. 40.
    Hooks T, Pedersen JF, Marx DB, Vogel KP (2006) Variation in the US photoperiod insensitive sorghum collection for chemical and nutritional traits. Crop Sci 46:751–757CrossRefGoogle Scholar
  41. 41.
    Hopkins AA, Vogel KP, Moore KJ (1993) Predicted and realized gains from selection for in vitro dry matter digestibility and forage yield in switchgrass. Crop Sci 33:253–258CrossRefGoogle Scholar
  42. 42.
    Hoskinson RL, Karlen DL, Birrell SJ, Radtke CW, Wilhelm WW (2007) Engineering, nutrient removal, and feedstock conversion evaluations of four corn stover harvest scenarios. Biomass Bioenergy 31:126–136CrossRefGoogle Scholar
  43. 43.
    Howe A, Sato S, Dweikat I, Fromm M, Clemente T (2006) Rapid and reproducible Agrobacterium-mediated transformation of sorghum. Plant Cell Rep 25:784–791PubMedCrossRefGoogle Scholar
  44. 44.
    Johansen JN, Vernhettes S, Hofte H (2006) The ins and outs of plant cell walls. Curr Opin Plant Biol 9:616–620PubMedCrossRefGoogle Scholar
  45. 45.
    Johnson JMF, Coleman MD, Gesch R, Jaradat A, Mitchell RB, Reicosky D, Wilhelm WW (2007) Biomass-bioenergy crops in the United States: a changing paradigm. Americas J Plant Sci Biotechnol 1:1–28Google Scholar
  46. 46.
    Jung HG, Mertens DR, Payne AJ (1997) Correlation of acid detergent lignin and Klason lignin with digestibility of forage dry matter and neutral detergent fiber. J Dairy Sci 80:1622–1628PubMedCrossRefGoogle Scholar
  47. 47.
    Jung HG, Varel VH (1988) Influence of forage type on ruminal bacterial populations and subsequent in vitro fiber digestion. J Dairy Sci 71:1526–1535 PubMedCrossRefGoogle Scholar
  48. 48.
    Karlen DL, Wollenhaupt NC, Erbach DC, Berry EC, Swan JB, Each NS, Jordahl JL (1994) Crop residue effects on soil quality following 10-years of no-till corn. Soil Tillage Res 31:149–167CrossRefGoogle Scholar
  49. 49.
    Lee DK, Boe A (2005) Biomass production of switchgrass in central South Dakota. Crop Sci Soc Am 45:2583–2590CrossRefGoogle Scholar
  50. 50.
    Lerouxel O, Cavalier DM, Liepman AH, Keegstra K (2006) Biosynthesis of plant cell wall polysaccharides—a complex process. Curr Opin Plant Biol 9:621–630PubMedCrossRefGoogle Scholar
  51. 51.
    Lindstrom MJ, Voorhees WB, Onstad CA (1984) Tillage systems and residue cover effects on infiltration in northwestern Corn Belt soils. J Soil Water Conserv 39:64–68Google Scholar
  52. 52.
    Liu ZL, Slininger PJ, Gorsich SW (2005) Enhanced biotransformation of furfural and hydroxymethylfurfural by newly developed ethanologenic yeast strains. Appl Biochem Biotechnol 121–124:451–460PubMedCrossRefGoogle Scholar
  53. 53.
    McLaren JS (2005) Crop biotechnology provides an opportunity to develop a sustainable future. Trends Biotechnol 23:339–342PubMedCrossRefGoogle Scholar
  54. 54.
    McLaughlin SB, Kszos LA (2005) Development of switchgrass (Panicum virgatum) as a bioenergy feedstock in the United States. Biomass Bioenergy 28:515–535CrossRefGoogle Scholar
  55. 55.
    Mielenz JR (2006) Bioenergy for ethanol and beyond. Curr Opin Biotechnol 17:303–4CrossRefGoogle Scholar
  56. 56.
    Missaoui AM, Fasoula VA, Bouton JH (2005) The effect of low plant density on response to selection for biomass production in switchgrass. Euphytica 142:1–12CrossRefGoogle Scholar
  57. 57.
    Missaoui AM, Paterson AH, Bouton JH (2005) Investigation of genomic organization in switchgrass (Panicum virgatum L.) using DNA markers. Theor Appl Genet 110:1372–1383 PubMedCrossRefGoogle Scholar
  58. 58.
    Mitchell RB, Anderson BE, Masters RA, Vogel KP, Klopfenstein TJ (2005a) Grazing evaluation of big bluestems bred for improved forage yield and digestibility. Crop Sci 45:2288–2292CrossRefGoogle Scholar
  59. 59.
    Mitchell RB, Vogel KP, Varvel G, Klopfenstein T, Clark D, Anderson B (2005b) Big Bluestem pastures in the Great Plains: an alternative to dryland corn. Rangelands 27:31–35CrossRefGoogle Scholar
  60. 60.
    Morris D (2006) The next economy: from dead carbon to living carbon. J Sci Food Agric 86:1743–1746CrossRefGoogle Scholar
  61. 61.
    Mulkey VR, Lee DK, Owens VN (2006) Management of switchgrass-dominated Conservation Reserve Program lands for biomass production in South Dakota. Crop Sci 46:712–720CrossRefGoogle Scholar
  62. 62.
    Nakamura T, Yamamori M, Hidaka S, Hoshino T (1992) Expression of HMW wx protein in Japanese common wheat (Triticum aestivum L.) cultivars. Jpn J Breed 42:681–685CrossRefGoogle Scholar
  63. 63.
    Nakamura T, Yamamori M, Hirano H, Hidaka S (1993) Decrease of waxy (Wx) protein in two common wheat cultivars with low amylose content. Plant Breed 111:99–105CrossRefGoogle Scholar
  64. 64.
    Nakamura T, Yamamori M, Hirano H, Hidaka S, Nagamine T (1995) Production of waxy (amylose-free) wheats. Mol Gen Genet 248:253–259PubMedCrossRefGoogle Scholar
  65. 65.
    NASS (2007) Acreage June 2007. Agricultural Statistics Board. USDA, NASSGoogle Scholar
  66. 66.
    Nelson RG, Ascough JC 2nd, Langemeier MR (2005) Environmental and economic analysis of switchgrass production for water quality improvement in northeast Kansas. J Environ Manage 79:336–347PubMedCrossRefGoogle Scholar
  67. 67.
    Oliver AL, Pedersen JF, Grant RJ, KlopfensteinTJ (2005a) Comparative effects of the sorghum bmr-6 and bmr-12 genes I: forage sorghum yield and quality. Crop Sci 45:2234–2239CrossRefGoogle Scholar
  68. 68.
    Oliver AL, Pedersen JF, Grant RJ, Klopfenstein TJ, Jose HD (2005b) Comparative effects of the sorghum bmr-6 and bmr-12 genes II: grain sorghum grain yield, stover yield, and stover quality. Crop Sci 45:2240–2245CrossRefGoogle Scholar
  69. 69.
    Parrish DJ, Fike JH (2005) The biology and agronomy of switchgrass for biofuels. Crit Rev Plant Sci 24:423–459CrossRefGoogle Scholar
  70. 70.
    Pedersen JF, Bean SR, Graybosch RA, Park SH, Tilley M (2005a) Characterization of waxy grain sorghum lines in relation to granule-bound starch synthase. Euphytica 144:151–156CrossRefGoogle Scholar
  71. 71.
    Pedersen JF, Graybosch RA, Funnell DL (2007) Occurrence of the waxy alleles wxa and wxb in waxy Sorghum Plant Introductions and their effect on starch thermal properties. Crop Sci 145:(in press)Google Scholar
  72. 72.
    Pedersen JF, Funnell DL, Toy JJ, Oliver AL, Grant RJ (2006a) Registration of ‘Atlas bmr-12’ forage sorghum. Crop Sci 46:478CrossRefGoogle Scholar
  73. 73.
    Pedersen JF, Funnell DL, Toy JJ, Oliver AL, Grant RJ (2006b) Registration of seven forage sorghum genetic stocks near-isogenic for the brown midrib genes bmr-6 and bmr-12. Crop Sci 46:490–491CrossRefGoogle Scholar
  74. 74.
    Pedersen JF, Funnell DL, Toy JJ, Oliver AL, Grant RJ (2006c) Registration of 12 grain sorghum genetic stocks near-isogenic for the brown midrib genes bmr-6 and bmr-12. Crop Sci 46:491–492CrossRefGoogle Scholar
  75. 75.
    Pedersen JF, Funnell DL, Vogel KP (2005) Impact of reduced lignin on plant fitness. Crop Sci 45:812–819CrossRefGoogle Scholar
  76. 76.
    Ragauskas AJ, Williams CK, Davison BH, Britovsek G, Cairney J, Eckert CA, Frederick WJ Jr, Hallett JP, Leak DJ, Liotta CL, Mielenz JR, Murphy R, Templer R, Tschaplinski T (2006) The path forward for biofuels and biomaterials. Science 311:484–489PubMedCrossRefGoogle Scholar
  77. 77.
    Rooney WL (2000) Genetics and cytogenetics. In: Smith CW, Frederiksen RA (eds) Sorghum: origin, history, technology, and production. Wiley, NY, pp 261–307Google Scholar
  78. 78.
    Rooney WL, Aydin S, Kuhlman LC (2005) Assessing the relationship between endosperm type and grain yield potential in sorghum (Sorghum bicolor L. Moench). Field Crops Res 14:199–205CrossRefGoogle Scholar
  79. 79.
    Rosenberger A, Kaul HP, Senn T, Aufhammer W (2002) Costs of bioethanol production from winter cereals: the effect of growing conditions and crop production intensity levels. Indust Crops Prod 15:91–102CrossRefGoogle Scholar
  80. 80.
    Saha BC, Cotta MA (2006) Ethanol production from alkaline peroxide pretreated enzymatically saccharified wheat straw. Biotechnol Prog 22:449–453PubMedCrossRefGoogle Scholar
  81. 81.
    Sanderson MA, Adler PR, Boateng A, Casler MD, Sarath G (2006) Switchgrass as a biofuels feedstock in the USA. Can J Plant Sci 86:1315–1325CrossRefGoogle Scholar
  82. 82.
    Sanderson MA, Read JC, Reed RL (1999) Harvest management of switchgrass for biomass feedstock and forage production. Agron J 91:5–10CrossRefGoogle Scholar
  83. 83.
    Sarath G, Baird LM, Vogel KP, Mitchell RB (2007) Internode structure and cell wall composition in maturing tillers of switchgrass (Panicum virgatum. L). Bioresour Technol 98:2985–2992PubMedCrossRefGoogle Scholar
  84. 84.
    Sarath G, Vogel KP, Mitchell RB, Baird LM (2005) Stem anatomy of switchgrass plants developed by divergent breeding cycles for tiller digestibility. Intl Grasslands Cong Proc, pp: 115Google Scholar
  85. 85.
    Schmer MR, Vogel KP, Mitchell RB, Moser LE, Eskridge KM, Perrin RK (2006) Establishment stand thresholds for switchgrass grown as a bioenergy crop. Crop Sci 46:157–161CrossRefGoogle Scholar
  86. 86.
    Shahbazi A, Li Y (2005) Availability of crop residues as sustainable feedstock for bioethanol production in North Carolina. Appl Biochem Biotechnol 129:41–54 CrossRefGoogle Scholar
  87. 87.
    Shadle G, Chen F, Srinivasa Reddy MS, Jackson L, Nakashima J, Dixon RA (2007) Down-regulation of hydroxycinnamoyl CoA: Shikimate hydroxycinnamoyl transferase in transgenic alfalfa affects lignification, development and forage quality. Phytochemistry 68:1521–1529PubMedCrossRefGoogle Scholar
  88. 88.
    Shi C, Koch G, Ouzunova M, Wenzel G, Zein I, Lubberstedt T (2006) Comparison of maize brown-midrib isogenic lines by cellular UV-microspectrophotometry and comparative transcript profiling. Plant Mol Biol 62:697–714PubMedCrossRefGoogle Scholar
  89. 89.
    Shi C, Uzarowska A, Ouzunova M, Landbeck M, Wenzel G, Lubberstedt T (2007) Identification of candidate genes associated with cell wall digestibility and eQTL (expression quantitative trait loci) analysis in a Flint × Flint maize recombinant inbred line population. BMC Genomics 8:22PubMedPubMedCentralCrossRefGoogle Scholar
  90. 90.
    Shrawat AK, Lorz H (2006) Agrobacterium-mediated transformation of cereals: a promising approach crossing barriers. Plant Biotechnol J 4:575–603PubMedCrossRefGoogle Scholar
  91. 91.
    Smart AJ, Schacht WH, Moser LE, Volesky JD (2004) Prediction of leaf/stem ratio using Near-Infrared Reflectance Spectroscopy (NIRS): A technical note. Agron J 96:316–318Google Scholar
  92. 92.
    Somleva MN (2006) Switchgrass (Panicum virgatum L.). Methods Mol Biol 344:65–73PubMedGoogle Scholar
  93. 93.
    Sticklen M (2006) Plant genetic engineering to improve biomass characteristics for biofuels. Curr Opin Biotechnol 17:315–319PubMedCrossRefGoogle Scholar
  94. 94.
    Takahiro N, Nishiba Y, Sato T, Suda I (2003) Properties of starches from several low-amylose rice cultivars. Cereal Chem 80:193–197CrossRefGoogle Scholar
  95. 95.
    Thomsen MH, Thygesen A, Jorgensen H, Larsen J, Christensen BH, Thomsen AB (2006) Preliminary results on optimization of pilot scale pretreatment of wheat straw used in coproduction of bioethanol and electricity. Appl Biochem Biotechnol 129–132:448–460PubMedGoogle Scholar
  96. 96.
    Tilman D, Hill J, Lehman C (2006) Carbon-negative biofuels from low-input high-diversity grassland biomass. Science 314:1598–1600PubMedCrossRefGoogle Scholar
  97. 97.
    Tobias CM, Twigg P, Hayden DM, Vogel KP, Mitchell RM, Lazo GR, Chow EK, Sarath G (2005) Gene discovery and the identification of associated short tandem repeats in switchgrass: a C4 perennial grass. Theor Appl Genet 111:956–964PubMedCrossRefGoogle Scholar
  98. 98.
    Tobias CM, Hayden DM, Twigg P, Sarath G (2006) Genic microsatellite markers derived from EST sequences of switchgrass (Panicum virgatum L.). Mol Ecol Notes 6:185–187CrossRefGoogle Scholar
  99. 99.
    Vidmantiene D, Juodeikiene G, Basinskiene L (2006) Technical ethanol production from waste of cereals and its products using a complex enzyme preparation. J Sci Food Agric 86:1732–1736 CrossRefGoogle Scholar
  100. 100.
    Vogel KP (1996) Energy Production from Forages (or American Agriculture - Back to the Future). J Soil Water Conserv 51:137–139Google Scholar
  101. 101.
    Vogel KP (2004) Switchgrass. In: Moser LE, Sollenberger L, Burson B (eds) Warm-season (C4) grasses. ASA-CSSA-SSSA Monograph,. Madison. pp 561–588Google Scholar
  102. 102.
    Vogel KP, Brejda JJ, Walters DT, Buxton DR (2002) Switchgrass biomass production in the Midwest USA: harvest and nitrogen management. Agron J 94:413–420CrossRefGoogle Scholar
  103. 103.
    Vogel KP, Hopkins AA, Moore KJ, Johnson KD, Carlson IT (2002) Winter survival in switchgrass populations bred for high IVDMD. Crop Sci 42:1857–1862CrossRefGoogle Scholar
  104. 104.
    Vogel KP, Jung HJG (2001) Genetic modification of herbaceous plants for feed and fuel. Crit Rev Plant Sci 20:15–49CrossRefGoogle Scholar
  105. 105.
    Vogel KP, Pedersen JF, Masterson SD, Toy JJ (1999) Evaluation of a filter bag system for NDF, ADF, and IVDMD forage analysis. Crop Sci 39:276–279CrossRefGoogle Scholar
  106. 106.
    Vogel KP, Sarath G, Mitchell RB (2005) Divergent breeding for tiller digestibility modified leaf, sheath, and stem composition of switchgrass (Panicum virgatum L.). Intl Grasslands Cong Proc, pp 116Google Scholar
  107. 107.
    Weimer PJ, Dien BS, Springer TL, Vogel KP (2005) In vitro gas production as a surrogate measure of the fermentability of cellulosic biomass to ethanol. Appl Microbiol Biotechnol 67:52–58PubMedCrossRefGoogle Scholar
  108. 108.
    Weimer PJ, Springer TL (2007) Fermentability of eastern gamagrass, big bluestem and sand bluestem grown across a wide variety of environments. Bioresour Technol 98:1615–1621PubMedCrossRefGoogle Scholar
  109. 109.
    WilhelmWW, Johnson JMF, Hatfield JL, Voorhees WB, Linden DR (2004) Crop and soil productivity response to corn residue removal: a review of the literature. Agron J 96:1–17CrossRefGoogle Scholar
  110. 110.
    Wollenweber B, Porter JR, Lubberstedt T (2005) Need for multidisciplinary research towards a second green revolution. Curr Opin Plant Biol 8:337–341PubMedCrossRefGoogle Scholar
  111. 111.
    Wu X, Zhao R, Bean SR, Seib PA, McLaren JS, Madl RL, Tuinstra M, Lenz MC, Wang D (2007) Factors impacting ethanol production from grain sorghum in the dry-grind process. Cereal Chem 84:130–136CrossRefGoogle Scholar
  112. 112.
    Wu X, Zhao R, Wang D, Bean SR, Seib PA, Tuinstra MR, Campbell M, O’Brien A (2006) Effects of amylase, corn protein, and corn fiber contents on production of ethanol from starch-rich media. Cereal Chem 83:569–575CrossRefGoogle Scholar

Copyright information

© USDA-Agricultural Research Service, US Government Agency 2008

Authors and Affiliations

  • Gautam Sarath
    • 1
  • Robert B. Mitchell
    • 1
  • Scott E. Sattler
    • 1
  • Deanna Funnell
    • 1
  • Jeffery F. Pedersen
    • 1
  • Robert A. Graybosch
    • 1
  • Kenneth P. Vogel
    • 1
  1. 1.Grain, Forage and Bioenergy Research Unit, USDA-ARS, 314 Biochemistry HallUniversity of NebraskaLincolnUSA

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