Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-23T02:28:45.223Z Has data issue: false hasContentIssue false

Geographic Patterns of Interspecific Hybridization between Spotted Knapweed (Centaurea stoebe) and Diffuse Knapweed (C. diffusa)

Published online by Cambridge University Press:  20 January 2017

Amy C. Blair*
Affiliation:
Graduate Degree Program in Ecology and Department of Bioagricultural Sciences and Pest Management, Colorado State University, Campus Delivery 1177, Fort Collins, CO 80523
Ruth A. Hufbauer
Affiliation:
Graduate Degree Program in Ecology and Department of Bioagricultural Sciences and Pest Management, Colorado State University, Campus Delivery 1177, Fort Collins, CO 80523
*
Corresponding author's E-mail: [email protected]

Abstract

Hybridization between species has the potential to change invasion dynamics. Field observations suggest that spotted knapweed and diffuse knapweed, two ecologically and economically destructive invasive plants, hybridize in their introduced range. As a first step towards understanding whether hybridization has affected the dynamics of the invasion of these species, we conducted field surveys in the introduced (North American) and native (European) ranges to discern patterns of hybridization and measured fitness-related traits among field hybrids and parental species. In North America we detected plants with hybrid morphology in 97% of the diffuse knapweed sites (n = 40); such hybrid plants were taller and more often exhibited polycarpy than plants with typical diffuse knapweed morphology. Hybrids were not detected in North American spotted knapweed sites (n = 22). In most regions surveyed in Europe, diffuse knapweed and spotted knapweed were isolated from each other and existed as distinct, nonhybridizing species. However, in Ukraine, the two species frequently coexisted within a site, resulting in hybrid swarms. On average, the plants from the North American diffuse knapweed sites (including plants with both diffuse and hybrid morphology), were larger than the apparently pure diffuse knapweed in the native range. The cross-continental patterns of hybridization likely are explained by differences in cytology. It recently has been confirmed that the spotted knapweed in North America is tetraploid whereas the diffuse knapweed is diploid. Genetic incompatibilities associated with these two cytotypes likely prevent ongoing hybridization. We hypothesize that hybrid individuals were introduced to North America along with diffuse knapweed. Because plants with hybrid morphology are found in nearly all North American diffuse knapweed sites, the introduction of hybrids likely occurred early in the invasion of diffuse knapweed. Thus, although the presence of hybrids might facilitate the ongoing invasion of diffuse knapweed into North America, elevated concern regarding their presence might not be warranted. Because such individuals are not likely to represent a new hybridization event, currently effective management strategies used in diffuse knapweed sites should not need alteration.

Type
Research
Copyright
Copyright © Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

Ayers, D. R., Garcia-Rossi, D., Davis, H. G., and Strong, D. R. 1999. Extent and degree of hybridization between exotic (Spartina alterniflora) and native (S. foliosa) cordgrass (Poaceae) in California, USA determined by random amplified polymorphic DNA (RAPDs). Mol. Ecol 8:11791186.Google Scholar
Blair, A. C., Hanson, B. D., Brunk, G. R., Marrs, R. A., Westra, P., Nissen, S. J., and Hufbauer, R. A. 2005. New techniques and findings in the study of a candidate allelochemical implicated in invasion success. Ecol. Lett 8:10391047.CrossRefGoogle Scholar
Blair, A. C., Nissen, S. J., Brunk, G. R., and Hufbauer, R. A. 2006. A lack of evidence for a role of the putative allelochemical (±)-catechin in spotted knapweed invasion success. J. Chem. Ecol 32:23272331.CrossRefGoogle ScholarPubMed
Blair, A. C., Schaffner, U., Häfliger, P., Meyer, S. K., and Hufbauer, R. A. 2008. How do biological control and hybridization affect enemy escape. Biol. Control 46:358370.CrossRefGoogle Scholar
Blair, A. C. and Wolfe, L. M. 2004. The evolution of an invasive plant: an experimental study with Silene latifolia . Ecology 85:30353042.CrossRefGoogle Scholar
Blossey, B. and Notzold, R. 1995. Evolution of increased competitive ability in invasive nonindigenous plants—a hypothesis. J. Ecol 83:887889.Google Scholar
Blumenthal, D. M. and Hufbauer, R. A. 2007. Increased plant size in exotic populations: a common-garden test with 14 invasive species. Ecology 88:27582765.CrossRefGoogle ScholarPubMed
Callaway, R. M. and Aschehoug, E. T. 2000. Invasive plants versus their new and old neighbors: a mechanism for exotic invasion. Science 290:521523.Google Scholar
Ellstrand, N. C. and Schierenbeck, K. A. 2000. Hybridization as a stimulus for the evolution of invasiveness in plants. Proc. Natl. Acad. Sci. U.S.A. 97:70437050.CrossRefGoogle ScholarPubMed
Fletcher, R. A. and Renney, A. J. 1963. A growth inhibitor found in Centaurea spp. Can. J. Plant Sci 43:475481.Google Scholar
Garcia-Jacas, J., Uysal, T., Romashchenko, K., Suarez-Santiago, V. N., Ertugrul, K., and Susanna, A. 2006. Centaurea revisited: a molecular survey of the Jacea group. Ann. Bot 98:741753.Google Scholar
Gaskin, J. F. and Schaal, B. A. 2002. Hybrid Tamarix widespread in U.S. invasion and undetected in native Asian range. Proc. Natl. Acad. Sci. U.S.A. 99:1125611259.CrossRefGoogle ScholarPubMed
Gáyer, G. 1909. Vier neue Centaureen der Flora Botanikai von Ungarn. Magyar Botanikai Lapok 8:5861.Google Scholar
Grosholz, E. D. and Ruiz, G. M. 2003. Biological invasions drive size increases in marine and estuarine invertebrates. Ecol. Lett 6:705710.CrossRefGoogle Scholar
Harrod, R. J. and Taylor, R. J. 1995. Reproduction and pollination biology of Centaurea and Acroptilon species, with emphasis on C. diffusa . Northwest Sci 69:97105.Google Scholar
Hufbauer, R. A. and Sforza, R. 2008. Multiple introductions of two invasive Centaurea taxa inferred from cpDNA haplotypes. Divers. Distrib 14:252261.Google Scholar
Jakobs, G., Weber, E., and Edwards, P. J. 2004. Introduced plants of the invasive Solidago gigantean (Asteraceae) are larger and grow denser than conspecifics in the native range. Divers. Distrib 10:1119.CrossRefGoogle Scholar
Katerina, B., Mandak, B., and Kasparova, I. 2004. How does Reynoutria invasion fit the various theories of invasibility. J. Veg. Sci 15:495504.Google Scholar
Khattree, R. and Naik, D. N. 2000. Multivariate Data Reductuion and Discrimination with SAS Software. Cary, NC. SAS Institute, Inc 442.Google Scholar
Lacey, J. R., Marlow, C. B., and Lane, J. R. 1989. Influence of spotted knapweed (Centaurea maculosa) on surface water runoff and sediment yield. Weed Technol 3:627631.Google Scholar
Leger, E. A. and Rice, K. J. 2003. Invasive California poppies (Eschscholzia californica Cham.) grow larger than native individuals under reduced competition. Ecol. Lett 6:257264.Google Scholar
Lexer, C., Welch, M. E., Raymond, O., and Rieseberg, L. H. 2003. The origin of ecological divergence in Helianthus paradoxus (Asteraceae): selection on transgressive characters in a novel hybrid habitat. Evolution 57:19892000.Google Scholar
Locken, L. J. and Kelsey, R. G. 1987. Cnicin concentrations in Centaurea maculosa, spotted knapweed. Biochem. Syst. Ecol 15:313320.Google Scholar
Löve, A. 1978. IOPB Chromosome Number Reports LIX. Taxon 27:5361.Google Scholar
Löve, A. 1979. IOPB Chromosome Number Reports LXIV. Taxon 28:391408.Google Scholar
Marrs, R. A., Sforza, R., and Hufbauer, R. A. 2008a. When invasion increases population genetic structure: a study with Centaurea diffusa . Biol. Invasions 10:561572.Google Scholar
Marrs, R. A., Sforza, R., and Hufbauer, R. A. 2008b. Evidence for multiple introductions of Centaurea stoebe micranthos (spotted knapweed, Asteraceae) to North America. Mol. Ecol 17:41974208.CrossRefGoogle ScholarPubMed
Moore, R. J. and Frankton, C. 1954. Cytotaxonomy of three species of Centaurea adventive in Canada. Can. J. Bot 32:182186.CrossRefGoogle Scholar
Müller, H. 1989. Growth pattern of diploid and tetraploid spotted knapweed, Centaurea maculosa Lam. (Compositae), and effects of the root-mining moth Agapeta zoegana (L.) (Lep.:Cochylidae). Weed Res 29:103111.CrossRefGoogle Scholar
Ochsmann, J. 1998. Ein bestand von Centaurea × psammogena Gáyer (Centaurea diffusa Lam. × Centaurea stoebe L.) am NSG Sonnenstein (Thüringen). Florist. Rundbr 31:118125.Google Scholar
Ochsmann, J. 1999. Chromosomenzahlen einiger europäischer Centaurea-Sippen. Haussknechtia 7:5965.Google Scholar
Ochsmann, J. 2000. Morphologische und molekularsystematische Untersuchungen an der Centaurea stoebe L.-Gruppe (Asteraceae–Cardueae) in Europa. Diss. Bot 324.(Ph.D Dissertation). 242 p.Google Scholar
Ochsmann, J. 2001a. An overlooked hybrid in North America: Centaurea × psammogena Gáyer (diffuse knapweed × spotted knapweed). Pages 76. in Smith, L., editor. The First International Symposium of the Twenty-First Century. Albany, CA USDA-ARS. [Abstract].Google Scholar
Ochsmann, J. 2001b. On the taxonomy of spotted knapweed (Centaurea stoebe L.). Pages 3341. in Smith, L., editor. The First International Knapweed Symposium of the Twenty-First Century. Albany, CA USDA-ARS.Google Scholar
Ortega, Y. K., McKelvey, K. S., and Six, D. L. 2006. Invasion of an exotic forb impacts reproductive succes and site fidelity of a migratory songbird. Oecologia 149:340351.Google Scholar
Rieseberg, L. H., Kim, S. C., Randell, R. A., Whitney, K. D., Gross, B. L., Lexer, C., and Clay, K. 2007. Hybridization and the colonization of novel habitats by annual sunflowers. Genetica 129:149165.Google Scholar
Roché, B. F. and Roché, C. T. 1991. Identification, introduction, distribution, and economics of Centaurea species. Pages 274291. in James, L. F., Evans, J. O., Ralphs, M. H., and Child, R. D., editors. Noxious Range Weeds. Boulder, CO Westview.Google Scholar
SAS Institute 2002. JMP Statistics and Graphics Guide. Version 5. Cary, NC SAS Institute Inc. 707.Google Scholar
Sheley, R. L., Jacobs, J. S., and Carpinelli, M. L. 1999. Spotted knapweed. Pages 350361. in Sheley, R. L. and Petroff, J. K., editors. Biology and Management of Noxious Rangeland Weeds. Corvallis, OR Oregon State University Press.Google Scholar
Sheley, R. L., Olson, B. E., and Larson, L. L. 1997. Effect of weed seed rate and grass defoliation level on diffuse knapweed seedlings. J. Range Manag 50:3943.Google Scholar
Siemann, E. and Rogers, W. E. 2001. Genetic differences in growth of an invasive tree. Ecol. Lett 4:514518.Google Scholar
Thébaud, C. and Simberloff, D. 2001. Are plants really larger in their introduced ranges. Am. Nat 157:231236.Google Scholar
Tyser, R. W. and Key, C. H. 1988. Spotted knapweed in natural areas fescue grasslands – an ecological assessment. Northwest Sci 62:151160.Google Scholar
Watson, A. K. and Renney, A. J. 1974. The biology of Canadian weeds: Centaurea diffusa and C. maculosa . Can. J. Plant Sci 54:687701.Google Scholar
Willis, A. J., Memnot, J., and Forrester, R. I. 2000. Is there evidence for the post-invasvion evolution of increased size among invasive plant species. Ecol. Lett 3:275283.Google Scholar