Skip to main content Accessibility help

Temperature effects on three downy brome (Bromus tectorum) seed collections inoculated with the fungal pathogen Pyrenophora semeniperda

  • Krista A. Ehlert (a1), Zachariah Miller (a2), Jane M. Mangold (a3), Fabian Menalled (a4) and Alexandra Thornton (a5)...


Downy brome (Bromus tectorum L., syn. cheatgrass) is a winter annual grass that invades North American cropping, forage, and rangeland systems. Control is often difficult to achieve, because B. tectorum has a large seedbank, which results in continuous propagule pressure. Pyrenophora semeniperda (Brittlebank and Adam) Shoemaker, a soilborne fungal pathogen, has been investigated as a biological control for B. tectorum, because it can kill seeds that remain in the seedbank, thereby reducing propagule pressure. Temperature influences P. semeniperda and has not been investigated in the context of seeds collected from different B. tectorum locations, that may vary in susceptibility to infection. We compared the effects of temperature (13, 17, 21, 25 C) and B. tectorum seed locations (range, crop, subalpine) with different mean seed weights on infection rates of P. semeniperda using a temperature-gradient table. Infection differed by seed location (P < 0.001) and temperature (P < 0.001), with lighter-weight seeds (i.e., range and subalpine) more susceptible to P. semeniperda infection. Infection increased as temperature increased and was higher at 21 C (66.7 ± 6.7%) and 25 C (73.3 ± 6.0%). Germination was affected by seed location (P < 0.001) and temperature (P = 0.019). Germination was highest for the crop seed location (45.4 ± 4.2%) and overall decreased at higher temperatures (21 and 25 C). Our results suggest that B. tectorum seeds from a crop location are less affected by P. semeniperda than those from range and subalpine locations. Moreover, this demonstrates a temperature-dependent effect on all populations.


Corresponding author

Author for correspondence: Krista A. Ehlert, Department of Natural Resource Management, South Dakota State University, West River Ag Center, Rapid City, SD 57702. (Email:


Hide All

Associate Editor: John Cardina, Ohio State University



Hide All
Allen, PS, Meyer, SE (2002) Ecology and ecological genetics of seed dormancy in downy brome. Weed Sci 50:241247
Allen, PS, Meyer, SE, Beckstead, J (1995) Patterns of after-ripening in Bromus tectorum L. J Exp Bot 46:17371744
Barth, CW, Meyer, SE, Beckstead, J, Allen, PS (2015) Hydrothermal time models for conidial germination and mycelial growth of the seed pathogen Pyrenophora semeniperda. Fungal Biol 119:720730
Beckstead, J, Meyer, SE, Allen, PS (1996) Bromus tectorum seed germination: between-population and between-year variation. Can J Bot 74:875882
Beckstead, J, Meyer, SE, Connolly, BM, Huck, MB, Street, LE (2010) Cheatgrass facilitates spillover of a seed bank pathogen onto native grass species. J Ecol 98:168177
Beckstead, J, Meyer, SE, Molder, CJ, Smith, C (2007) A race for survival: can Bromus tectorum seeds escape Pyrenophora semeniperda-caused mortality by germinating quickly?. Ann Bot (Lond) 99:907914
Black, JN (1956) The influence of seed size and depth of sowing on pre-emergence and early vegetative growth of subterranean clover. Aust J Agric Res 7:98109
Bradley, BA (2009) Regional analysis of the impacts of climate change on cheatgrass invasion shows potential risk and opportunity. Glob Chang Biol 15:196208
Bradley, BA, Blumenthal, DM, Wilcove, DS, Ziska, LH (2010) Predicting plant invasions in an era of global change. Trends Ecol Evol 25:310318
Campbell, MA, Medd, RW (2003) Leaf, floret and seed infection of wheat by Pyrenophora semeniperda. Plant Pathol 52:437447
Campbell, MA, Medd, RW, Brown, JB (2003) Optimizing conditions for growth and sporulation of Pyrenophora semeniperda. Plant Pathol 52:448454
Concilio, AL, Loik, ME, Belnap, J (2013) Global change effects on Bromus tectorum L. (Poaceae) at its high-elevation range margin. Glob Change Biol 19:161172
Crist, TO, Friese, CF (1993) The impact of fungi on soil seeds: implications for plants and granivores in a semiarid shrub-steppe. Ecology 74:22312239
Ehlert, KA (2013) Enhancing Efficacy of Herbicides to Control Cheatgrass on Montana Range, Pasture, and Conservation Reserve Program (CRP). MS thesis. Bozeman: Montana State University. 113 p
Ehlert, KA, Mangold, JM, Engel, RE (2014) Integrating the herbicide imazapic and the fungal pathogen Pyrenophora semeniperda to control Bromus tectorum. Weed Res 54:418424
Elton, CS (2001) Animal Ecology. Chicago: University of Chicago Press. 296 p
Evans, RA, Young, JA (1972) Microsite requirements for establishment of annual rangeland weeds. Weed Sci 20:350356
Finch, H, Allen, PS, Meyer, SE (2013) Environmental factors influencing Pyrenophora semeniperda-caused seed mortality in Bromus tectorum. Seed Sci Res 23:5766
Harper, JL, Obeid, M (1967) Influence of seed size and depth of sowing on the establishment and growth of varieties of fiber and oil seed flax. Crop Sci 7:527532
Harris, G (1976) Factors of Plant Competition in Seeding Pacific Northwest Bunchgrass Ranges. Research Center Bulletin 820. Pullman: Washington State University, College of Agriculture. 21 p
Hawkins, KK, Allen, PS, Meyer, SE (2017) Secondary dormancy induction and release in Bromus tectorum seeds: the role of temperature, water potential and hydrothermal time. Seed Sci Res 27:1225
Hellmann, JJ, Byers, JE, Bierwagen, BG, Dukes, JS (2008) Five potential consequences of climate change for invasive species. Conserv Biol 22:534–453
Hulbert, LC (1955) Ecological studies of Bromus tectorum and other annual bromegrasses. Ecol Mongr 25:181213
[ISTA] International Seed Testing Association (2018) International Rules for Seed Testing. Accessed: January 1, 2018
Kulmatiski, A, Beard, KH, Stark, JM (2006) Exotic plant communities shift water-use timing in a shrub-steppe ecosystem. Plant Soil 288:271284
Leger, EA, Espeland, EK, Merrill, KR, Meyer, SE (2009) Genetic variation and local adaptation at a cheatgrass (Bromus tectorum) invasion edge in western Nevada. Mol Ecol 18:43664379
Mack, RN (1981) Invasion of Bromus tectorum L. into Western North America: an ecological chronicle. Agro-Ecosyst 7:145165
Masi, M, Evidente, A, Meyer, S, Nicholson, J, Muñoz, A (2014a) Effect of strain and cultural conditions on the production of cytochalasin B by the potential mycoherbicide Pyrenophora semeniperda (Pleosporaceae, Pleosporales). Biocontrol Sci Technol 24:5364
Masi, M, Meyer, S, Cimmino, A, Andolfi, A, Evidente, A (2014b) Pyrenophoric acid, a phytotoxic sesquiterpenoid penta-2, 4-dienoic acid produced by a potential mycoherbicide, Pyrenophora semeniperda. J Nat Prod 77:925930
Medd, RWA, Murray, GMB, Pickering, DIA (2003) Review of the epidemiology and economic importance of Pyrenophora semeniperda. Australas Plant Pathol 32:539550
Meyer, SE, Allen, PS (2009) Predicting seed dormancy loss and germination timing for Bromus tectorum in a semi-arid environment using hydrothermal time models. Seed Sci Res 19:225239
Meyer, SE, Beckstead, J, Allen, PS, Smith, DC (2008a) A seed bank pathogen causes seedborne disease: Pyrenophora semeniperda on undispersed grass seeds in western North America. Can J Plant Pathol 30:525533
Meyer, SE, Clement, S, Beckstead, J, inventors; the United States of America as represented by the Secretary of Agriculture and Gonzaga University, assignees (2017) April 18. Annual brome control using a native fungal seed pathogen. US patent 9, 622, 487 B2
Meyer, SE, Nelson, DL, Clement, S, Beckstead, J (2008b) Cheatgrass (Bromus tectorum) biocontrol using indigenous fungal pathogens. Pages 6167 in Proceedings—Shrublands Under Fire: Disturbance and Recovery in a Changing World. Fort Collins, CO: USDA Forest Service Proceedings RMRS-P-52
Meyer, SE, Quinney, D, Nelson, DL, Weaver, J (2007) Impact of the pathogen Pyrenophora semeniperda on Bromus tectorum seedbank dynamics in North American cold deserts. Weed Res 47:5462
R Core Team (2017) R: A Language and Environment for Statistical Computing. Vienna, Austria: R Foundation for Statistical Computing
Rice, PM (2005) Downy brome, Bromus tectorum L. Pages 147170 in Duncan, CA, Clark, JK, eds. Invasive Plants of Range and Wildlands and Their Environmental, Economic, and Societal Impacts. Lawrence, KS: Weed Science Society of America
Schaal, BA (1980) Reproductive capacity and seed size in Lupinus texensis. Am J Bot 67:703709
Seastedt, TR (2015) Biological control of invasive plant species: a reassessment for the Anthropocene. New Phytol 205:490502
Seipel, T, Rew, L, Taylor, K, Maxwell, B, Lehnhoff, E (2016) Disturbance type influences resilience and resistance to Bromus tectorum invasion in the sagebrush steppe. Appl Veg Sci 21:385394
Stewart, TE (2009) The Grass Seed Pathogen Pyrenophora semeniperda as a Biocontrol Agent for Annual Brome Grasses. Ph.D dissertation. Provo, UT: Brigham Young University. 70 p
Taylor, K, Brummer, T, Rew, L, Lavin, M, Maxwell, BD (2014) Bromus tectorum response to fire varies with climate conditions. Ecosystems 17:960973
[USDA-NRCS] U.S. Department of Agriculture-Natural Resources Conservation Service (2016) Web Soil Survey. Accessed: December 20, 2016
[WRCC] Western Regional Climate Center (2016) Recent Climate in the West. Accessed: December 20, 2016
Zelikova, TJ, Hufbauer, RA, Reed, SC, Wertin, T, Fettig, C, Belnap, J (2013) Eco-evolutionary responses of Bromus tectorum to climate change: implications for biological invasions. Ecol Evol 3:13741387


Temperature effects on three downy brome (Bromus tectorum) seed collections inoculated with the fungal pathogen Pyrenophora semeniperda

  • Krista A. Ehlert (a1), Zachariah Miller (a2), Jane M. Mangold (a3), Fabian Menalled (a4) and Alexandra Thornton (a5)...


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.