Reduction of Ethanol Yield from Switchgrass Infected with Rust Caused by Puccinia emaculata
- 243 Downloads
Switchgrass (Panicum virgatum) is an important biofuel crop candidate thought to have low disease susceptibility. As switchgrass production becomes more prevalent, monoculture and production fields in close proximity to one another may increase the spread and severity of diseases such as switchgrass rust caused by the pathogen Puccinia emaculata. The objective of this research was to examine the impact of rust on ethanol yield in switchgrass. In 2010 and 2012, naturally infected leaves from field-grown ‘Alamo’ and ‘Kanlow’ in Knoxville, TN (2010, 2012) and Crossville, TN (2012) were visually categorized as exhibiting low, medium, or high disease based on the degree of chlorosis and sporulation. P. emaculata was isolated from each disease range to confirm infection. Samples from 2010 were acid/heat pretreated and subjected to two runs of simultaneous saccharification and fermentation (SSF) with Saccharomyces cerevisiae D5A to measure ethanol yield. Near-infrared spectroscopy (NIRS) was used to estimate ethanol yield for 2012 samples. SSF and NIRS data were analyzed separately using ANOVA. Disease level effects were significant within both models (P < 0.05) and both models explained a large amount of variation in ETOH (SSF: R 2 = 0.99, NIRS: R 2 = 0.99). In the SSF dataset, ethanol was reduced by 35 % in samples exhibiting medium disease symptoms and by 55 % in samples exhibiting high disease symptoms. In the NIRS dataset, estimated ethanol was reduced by 10 % in samples exhibiting medium disease symptoms and by 21 % in samples exhibiting high disease symptoms. Results indicate that switchgrass rust will likely have a negative impact on ethanol yield in switchgrass grown as a biofuel crop.
KeywordsNIRS Rust Puccinia emaculata Switchgrass Ethanol SSF Panicum virgatum
We thank the funders of this research, which included the University of Tennessee AgResearch and The BioEnergy Science Center, a U.S. Department of Energy Bioenergy Research Center supported by the Office of Biological and Environmental Research in the DOE Office of Science.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no competing interests.
- 2.Gravert CE, Munkvold GP (2002) Fungi and diseases associated with cultivated switchgrass in Iowa. J Iowa Acad Sci 109(1, 2):30–34Google Scholar
- 7.Farr DE, Bills GF, Chamuris GP, Rossman AY (1995) Fungi on plants and plant products in the United States. APS, St PaulGoogle Scholar
- 8.Tiffany LH, Knaphus G (1985) The rust fungi (Uredinales) of the Loess Hills region of Iowa. J Iowa Acad Sci 92(5):186–188Google Scholar
- 9.Gilman JC, Archer WA (1929) The fungi of Iowa parasitic on plants. Iowa State Coll J Sci 3:299–507Google Scholar
- 10.Hagan AK, Akridge JR (2013) Efficacy of fungicides for the control of rust on switchgrass. In: Dumenyo K (ed) SNA Res. Conf. Pathology and Nematology, pp 201–204Google Scholar
- 11.Li Y, Windham M, Trigiano R, Windham A, Ownley B, Gwinn K, Zale J, Spiers J (2009) Cultivar-specific interactions between switchgrass and Puccinia emaculata. Phytopathology 99(6):S72Google Scholar
- 12.Garland CD (2008) Growing and harvesting switchgrass for ethanol production in Tennessee. UT Biofuels Initiative - SP701-A-5M-5/08, vol SP701-A-5M-5/08. UT Extension; Knoxville, TNGoogle Scholar
- 14.Dowe N, McMillan J (2001) SSF experimental protocols—lignocellulosic biomass hydrolysis and fermentation. Laboratory Analytical Procedure, vol NREL/TP-510-42630. National Renewable Energy LaboratoryGoogle Scholar
- 16.Murray I, Cowe I (2004) Sample preparation. In: Roberts CA, Workman J, Reeves JB (eds) Near-infrared spectroscopy in agriculture, vol 44. American Society of Agronomy, Inc., Crop Science Society of America, Inc., Soil Science Society of America, Inc., Madison, WI, pp 75–112Google Scholar
- 18.Mixed hay: NIRS Forage and Feed Testing Consortium, June 2007 mixed hay calibration, file name: mh50-3. Parameters used: DM, CP, ADF, dNDF48, NDF, Ca, P, K, Mg, ash, fat, lignin, RUPGoogle Scholar
- 20.SAS 9.3 TS Level 1M2. SAS Institute, CaryGoogle Scholar
- 21.Arthur JC (1934) Manual of rusts in United States and Canada. Science Press, LancasterGoogle Scholar
- 26.Manners M (1982) Pathways of glucose assimilation in Puccinia graminis. J Gen Microbiol 128(11):2621–2630Google Scholar
- 31.Liu XY, Jin JY, He P, Gao W, Li WJ (2007) Effect of potassium chloride on lignin metabolism and its relation to resistance of corn to stalk rot. Sci Agric Sin 40:2780–2787Google Scholar
- 33.Ride JP (1978) The role of cell wall alterations in resistance to fungi. Ann Appl Biol 89:302–306Google Scholar