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Ecology and ecological genetics of seed dormancy in downy brome

Published online by Cambridge University Press:  20 January 2017

Phil S. Allen  and
Susan E. Meyer
Susan E. Meyer
Affiliation:
USDA Forest Service Rocky Mountain Research Station Shrub Sciences Laboratory, Provo, UT 84606
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Abstract

Downy brome, an obligately selfing winter annual, has invaded a variety of habitats in western North America. Seeds are at least conditionally dormant at dispersal in early summer and lose dormancy through dry after-ripening. In the field, patterns of germination response at dispersal vary among populations and across years within populations. Degree of dormancy at summer temperatures in recently harvested seeds, as well as rate of dormancy loss during dry storage, can be related to the risk of premature summer germination in different habitats. Patterns of dormancy loss are predictable and can be modeled using hydrothermal time concepts. To assess the relative contribution of genotype and maturation environment, multiple parental lines from contrasting populations were grown for three generations under manipulated greenhouse conditions. Significant germination response differences among populations were observed, as well as major differences among full-sib families. Among-population variation accounted for over 90% of the variance in germination traits, whereas within-family variance accounted for 1% or less. Populations from predictable extreme environments (subalpine meadow and warm desert margin) showed significantly less variation among families than did populations from less predictable environments (cold desert, foothill, and plains). Environmental conditions that shortened the seed ripening period (water stress and high temperature) resulted in reduced seed dormancy level at maturation, but there were strong inbred line–environment interactions. For fully after-ripened seeds, inbred line and environmental effects were no longer evident, indicating that differences in genotype and maturation environment function mainly to regulate dormancy and dormancy loss rather than to mediate response patterns of nondormant seeds.

Keywords

Downy brome, Bromus tectorum L. BROTEGerminationheritabilitymodelingpopulation genetics
Type
Research Article
Information
Weed Science , Volume 50 , Issue 2 , April 2002 , pp. 241 - 247
Copyright
Copyright © Weed Science Society of America 

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References

Literature Cited

Allen, P. S., Meyer, S. E., and Beckstead, J. 1995. Patterns of seed afterripening in Bromus tectorum L. J. Exp. Bot. 46:1737–1744.Google Scholar
Angevine, M. W. and Chabot, B. F. 1979. Seed germination syndromes in higher plants. Pages 188–206 In Solbrig, O. T., Jain, S., Hohnson, G. B., and Raven, P. H., eds. Topics in Plant Population Biology. New York: Columbia University Press.Google Scholar
Bauer, M. C., Meyer, S. E., and Allen, P. S. 1998. A simulation model to predict dormancy loss of Bromus tectorum L. seeds in the field. J. Exp. Bot. 49:1235–1244.Google Scholar
Beckstead, J., Meyer, S. E., and Allen, P. S. 1996. Bromus tectorum seed germination: between-population and between-year variation. Can. J. Bot. 74:875–882.Google Scholar
Billings, W. D. 1994. Ecological impacts of cheatgrass and resultant fire on ecosystems in the western Great Basin. Pages 22–30 In Monsen, S. B. and Kitchen, S. G., eds. Proceedings—Ecology and Management of Annual Rangelands. Ogden, UT: USDA Forest Service INT-GTR-313.Google Scholar
Bradford, K. J. 1990. A water relations analysis of seed germination rates. Plant Physiol. 94:840–849.Google Scholar
Bradford, K. J. 1995. Water relations in seed germination. Pages 351–396 In Kigel, J. and Galili, G., eds. Seed Development and Germination. New York: Marcel Dekker.Google Scholar
Bradford, K. J. 2002. Applications of hydrothermal time to quantifying and modeling seed germination and dormancy. Weed Sci. 50:248–260.CrossRefGoogle Scholar
Bradshaw, A. D. 1965. Evolutionary significance of phenotypic plasticity in plants. Adv. Genet. 13:115–155.Google Scholar
Christensen, M., Meyer, S. E., and Allen, P. S. 1996. A hydrothermal time model of seed after-ripening in Bromus tectorum L. Seed Sci. Res. 6:1–9.CrossRefGoogle Scholar
D’Antonio, C. M. and Vitousek, P. M. 1992. Biological invasions by exotic grasses, the grass-fire cycle, and global change. Annu. Rev. Ecol. Syst. 23:63–88.Google Scholar
Garbutt, K. and Witcombe, J. R. 1986. The inheritance of seed dormancy in Sinapis arvensis L. Heredity 56:25–31.Google Scholar
Gummerson, R. J. 1986. The effect of constant temperatures and osmotic potentials on the germination of sugar beet. J. Exp. Bot. 37:729–741.CrossRefGoogle Scholar
Lane, M. D. and Lawrence, M. J. 1995. Genetics of seed dormancy in Papaver rheoas . Heredity 15:315–320.Google Scholar
Mack, R. N. 1981. Invasion of Bromus tectorum L. into western North America: an ecological chronicle. Agro-Ecosystems 7:145–165.Google Scholar
Mack, R. N. and Pyke, D. A. 1984. The demography of Bromus tectorum: the role of microclimate, grazing, and disease. J. Ecol. 72:731–748.Google Scholar
McKone, M. K. 1985. Reproductive biology of several bromegrasses (Bromus): breeding system, pattern of fruit maturation, and seed set. Am. J. Bot. 72:1334–1339.CrossRefGoogle Scholar
Meyer, S. E. 1992. Habitat correlated variation in firecracker penstemon (Penstemon eatonii Gray: Scrophulariaceae) seed germination response. Bull. Torrey Bot. Club 119:268–279.Google Scholar
Meyer, S. E. and Allen, P. S. 1999a. Ecological genetics of seed germination regulation in Bromus tectorum L. I. Phenotypic variance among and within populations. Oecologia 120:27–34.Google Scholar
Meyer, S. E. and Allen, P. S. 1999b. Ecological genetics of seed germination regulation in Bromus tectorum L. II. Reaction norms in response to a water stress gradient imposed during seed maturation. Oecologia 120:35–43.Google Scholar
Meyer, S. E., Allen, P. S., and Beckstead, J. 1997. Seed germination regulation in Bromus tectorum (Poaceae) and its ecological significance. Oikos 78:475–485.CrossRefGoogle Scholar
Meyer, S. E., Debaene-Gill, S. B., and Allen, P. S. 2000. Using hydrothermal time concepts to model seed germination response to temperature, dormancy loss, and priming effects in Elymus elymoides . Seed Sci. Res. 10:213–223.Google Scholar
Meyer, S. E. and Kitchen, S. G. 1994. Life history variation in blue flax (Linum perenne): seed germination phenology. Am. J. Bot. 81:528–535.Google Scholar
Meyer, S. E., McArthur, E. D., and Jorgensen, J. L. 1989. Variation in germination response to temperature in rubber rabbitbrush (Chrysothamnus nauseosus: Asteraceae) and its ecological implications. Am. J. Bot. 76:981–991.Google Scholar
Meyer, S. E. and Monsen, S. B. 1991. Habitat-correlated variation in mountain big sagebrush (Artemesia tridentata ssp. Vaseyana) seed germination patterns. Ecology 72:739–742.Google Scholar
Meyer, S. E., Nelson, D. L., and Clement, S. 2001. Evidence for resistance polymorphism in the Bromus tectorum-Ustilago bullata pathosystem: implications for biocontrol. Can. J. Plant Pathol. 23:1–9.Google Scholar
Milby, T. H. and Johnson, F. L. 1987. Germination of downy brome from southern Kansas, central Oklahoma, and north Texas. J. Range Manag. 40:534–536.CrossRefGoogle Scholar
Pierson, E. A. and Mack, R. N. 1990. The population biology of Bromus tectorum in forests. I. Distinguishing the opportunity for dispersal from environmental restriction. Oecologia 84:519–525.Google Scholar
Platenkamp, G. A. and Shaw, R. G. 1993. Environmental and genetic maternal effects on seed characters in Nemophila menziesii . Evolution 47:540–555.Google Scholar
Ramakrishnan, A., Coleman, C., Meyer, S. E., and Fairbanks, D. J. 2002. Microsatellite markers and polymorphism in cheatgrass (Bromus tectorum). Pages 95–97 in McArthur, E. D. and Fairbanks, D. J., compilers. Proceedings—Eleventh Wildland Shrub Symposium: Shrubland Ecosystem Genetics and Biodiversity. Ogden, UT: USDA Forest Service. In press.Google Scholar
Rice, K. J. and Mack, R. N. 1991. Ecological genetics of Bromus tectorum . I. A hierarchical analysis of phenotypic variation. Oecologia 77:84–90.Google Scholar
Steiner, J. J. 1990. Seedling rate of development index: indicator of vigour and seedling growth response. Crop Sci. 30:1264–1271.Google Scholar
Whisenant, S. G. 1990. Changing fire frequencies on Idaho's Snake River plains: ecological and management implications. Pages 4–10 In McArthur, E. D., ed. Proceedings—Symposium on Cheatgrass Invasion, Shrub Die-Off, and Other Aspects of Shrub Biology and Management. Ogden, UT: USDA Forest Service INT-GTR-276.Google Scholar