, Volume 148, Issue 1–2, pp 185–202 | Cite as

A non-invasive crop ideotype to reduce invasive potential

  • N. O. AndersonEmail author
  • N. Gomez
  • S. M. Galatowitsch


In plant breeding programs, qualitative and quantitative traits confer market value and, thus, constitute the basis for developing breeding criteria during crop domestication. Some traits such as high male/female fertility are advantageous in the wild and could enable the evolution of cultivated crops into invasive weeds. Other traits, e.g. sterility, are not expected to confer invasiveness. To date there has been very limited involvement in invasion risk assessment by plant breeders. Thus, in this paper we propose that trait-based selection of potential crop species be coupled with species design in the creation of a “non-invasive crop ideotype” as an avenue to reduce invasiveness during domestication. The non-invasive crop ideotype embodies the ideal characteristics for a crop to excel in cultivated environment(s) but minimizes the likelihood it will establish and spread in non-cultivated environments, constituting the underlying foundation for all breeding objectives, choice(s) of breeding methodologies, and propagation techniques for non-invasive crop release. Using ornamental (floriculture) horticultural crops as an example, we identify 10 traits to be used individually or in combination to reduce invasiveness while retaining commercial value: reduced genetic variation in propagules, slowed growth rates, non-flowering, elimination of asexual propagules, lack of pollinator rewards, non-shattering seed, non-fleshy fruits, lack of seed germination, sterility, and programmed death (apotopsis). A non-invasive crop ideotype would constitute the underlying foundation for all breeding objectives, the choice(s) of breeding methodologies, and propagation technique(s). The ideotype should be flexible and should adjust to species- and crop-specific traits to account for the intended use. For example, development of sterile cultivars may have negligible effects in reducing invasiveness if the crops spread vegetatively. A non-invasive crop ideotype may increase the direct participation of plant breeders, who are the professionals directly involved in the collection, development and release of new crops, in reducing the invasive potential of ornamental crops. Future research is required to determine the feasibility of incorporating each trait into various crops, use of classical or molecular techniques for creation of non-invasive crops, trait stability (lack of genotype × environment interaction over years and locations), consumer acceptance, and long-term viability.

Key Words

crop domestication floriculture crops invasive species ornamentals plant breeding 


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  1. Abd-El-Moneim, A.M., 1993. Selection for non-shattering common vetch, Vicia sativa L. Plant-Breed (Germany) 110(2): 168–171.CrossRefGoogle Scholar
  2. Adkins, J.A., D.J. Werner & T.G. Ranney, 2003. Prospects for genetically modified ornamental plants. Proc of the South Nursery Assoc 48: 502–504.Google Scholar
  3. Aguirre, P.J. & A.G. Smith, 1993. Molecular characterization of a gene encoding a cysteine-rich protein preferentially expressed in anthers of Lycopersicon esculentum. Plant Molec Biol 23: 477–487.CrossRefGoogle Scholar
  4. Allard, R.W., 1960. Principles of Plant Breeding. John Wiley, New York.Google Scholar
  5. Anderson, N.O., 1991. The discovery of day neutral chrysanthemums. Greenhouse Grower 9: 50–53.Google Scholar
  6. Anderson, N.O., 2001. New ornamental crops: A primary source of invasive species? Chicago Botanic Garden, New Ornamental Crops Research Symposium Program and Abstracts, Sept. 26–29, 2001, p. 13.Google Scholar
  7. Anderson, N., 2004a. Invasive horticultural crops (part 1): Why be concerned? Minnesota Nursery and Landscape Association, MNLA News 28(3): 36–40.Google Scholar
  8. Anderson, N., 2004b. Invasive horticultural crops (part 2): Where do they come from? Minnesota Nursery and Landscape Association, MNLA News 28(4): 28–33.Google Scholar
  9. Anderson, N., 2004c. Invasive horticultural crops (part 3): Who's monitoring and controlling them? Minnesota Nursery and Landscape Association, MNLA News 28(6): 45–47.Google Scholar
  10. Anderson, N., 2004d. Invasive horticultural crops (part 4): What can we do? Minnesota Nursery and Landscape Association, MNLA News 28(8): 36–40.Google Scholar
  11. Anderson, N., 2004e. Breeding flower seed crops. In: M. McDonald & F. Kwong (Eds.), Flower Seeds, pp. 53–86. CABI.Google Scholar
  12. Anderson, N.O. & P.D. Ascher, 1993. Male and female fertility of loosestrife (Lythrum) cultivars. J Am Soc Hort Sci 118(6): 851–858.Google Scholar
  13. Anderson, N.O. & P.D. Ascher, 2001. Selection of day-neutral, heat-delay-insensitive Dendranthema xgrandiflora genotypes. J Am Soc Hort Sci 126(6): 710–721.Google Scholar
  14. Anderson, N. & N. Gomez, 2004. Invasive horticultural crops (part 5): Will research offer solutions? Minnesota Nursery and Landscape Association, MNLA News 28(10): 34–40.Google Scholar
  15. Archibold, O.W., D. Brooks & L. Delanoy, 1997. An investigation of the invasive shrub European buckthorn, Rhamnus cathartica L., near Saskatoon, Saskatchewan. Can Field Nat 111: 617–621.Google Scholar
  16. Arisumi, T., 1978. Hybridization among diploid and tetraploid forms of New Guinea, Java, and Celebes Impatiens spp. J. Am Soc. Hort Sci 103(3): 355–361.Google Scholar
  17. Arisumi, T. & H.M. Cathey, 1976. The New Guinea impatiens. HortScience 11(1): 2.Google Scholar
  18. Armitage, A., 2000. Armitage's garden perennials: A color encyclopedia. Timber Press, Portland, Oregon.Google Scholar
  19. Avishai, M., 2005. Plant introduction in a mediterranean context: The review of a century in Israel. Part II. Landscape Plant News 16(1): 4–10.Google Scholar
  20. Ball Seed Company, 1999–2000. Seed and plant catalog. Ball Horticultural Company, W. Chicago, IL.Google Scholar
  21. Barrett, S.C.H. & B.J. Richardson, 1986. Genetic attributes of invading species. In: R.H. Groves & J.J. Burdon (Eds.), Ecology of Biological Invasions: An Australian Perspective, pp. 21–33. Australia Academy of Science, Canberra.Google Scholar
  22. Beardsell, D. & U. Norden, 2004. Ficus rubiginosa ‘Variegata ’, a chlorophyll deficient chimera with mosaic patterns created by cell divisions from the outer meristematic layer. Ann Bot 94(1): 51–58.PubMedCrossRefGoogle Scholar
  23. Beattie, D.J. & R.T. German, 1985. Perennials. In: J.W. Mastalerz & E.J. Holcomb (Eds.), Bedding Plants III: A Manual on the Culture of Bedding Plants as a Greenhouse Crop, pp. 510–525. Pennsylvania Flower Growers.Google Scholar
  24. Bell, G., 1988. Recombination and the immortality of the germ line. J Evol Biol 1(1): 67–82.CrossRefGoogle Scholar
  25. Briggs, D. & S.M. Walters, 1997. Plant Variation and Evolution, 3rd ed. Cambridge University Press.Google Scholar
  26. Bucciaglia, P.A., E. Zimmermann & A.G. Smith, 2003. Functional analysis of a β-1,3-glucanase gene (Tag 1) with anther-specific RNA and protein accumulation using antisense RNA inhibition. J Plant Physiol 160: 1367–1373.PubMedCrossRefGoogle Scholar
  27. Callaway, R.M. & E.T. Aschehoug, 2000. Invasive plants versus their new and old neighbors: A mechanism for exotic invasion. Science 290: 521–523.PubMedCrossRefGoogle Scholar
  28. Chaney, W.R., H.A. Holt, K.L. Scott, M. Johnson, R.L. McKenzie, T.E. Clua, A.A. & D.O. Gimenez, 2003. Environmental factors during seed development of narrow-leaved bird's-foot-trefoil (Lotus tenuis) influences subsequent dormancy and germination. Grass Forage Sci 58(4): 333–338.CrossRefGoogle Scholar
  29. Charlesworth, D., M.R. Morgan & B. Charlesworth, 1993. Mutation accumulation in finite populations. J Hered 84(5): 321–325.Google Scholar
  30. Chicago Botanic Garden, 1998. Chicago botanic garden identifies hardy Monarda. Am Nurseryman 188(11): 18–19.Google Scholar
  31. Clua, A.A. & D.O. Gimenez, 2003. Environmental factors during seed development of narrow-leaved bird's-foot-trefoil (Lotus tenuis) influences subsequent dormancy and germination. Grass Forage Sci 58(4): 333–338.CrossRefGoogle Scholar
  32. Collicut, L.M., 1989. ‘Marshall's Delight Monarda. HortScience 24: 525.Google Scholar
  33. Collicut, L.M. & C.G. Davidson, 1999. ‘Petite Delight Monarda. HortScience 34(1): 149–150.Google Scholar
  34. Conn, J., R. Gronquist & M. Mueller, 2003. Invasive plants in Alaska: Assessment of research priorities. Agroborealis 35(2): 13–18.Google Scholar
  35. Craig, R., 1968. Past, present, and future of seedling geraniums. Pennsylvania Flower Growers Bulletin 204: 1–2, 7.Google Scholar
  36. Craig, R. & L. Laughner, 1985. Breeding new cultivars. In: J.W. Mastalerz & E.J. Holcomb (Eds.), Bedding Plants III: A Manual on the Culture of Bedding Plants as a Greenhouse Crop, pp. 526–539. Pennsylvania Flower Growers.Google Scholar
  37. Crane, M.B. & W.J.C. Lawrence, 1934. The genetics of garden plants. MacMillan, London.Google Scholar
  38. Cutright, N.J., 1986. Regulation of purple loosestrife by states in the midwest. Proc N Central Weed Control Conf 41: 123–125.Google Scholar
  39. Davis, M. & K. Thompson, 2000. Eight ways to be a colonizer; two ways to be an invader: A proposed nomenclature scheme for invasion ecology. Bull Ecol Soc Am 81: 226–230.Google Scholar
  40. Detzner, T., 1995. Controlling nuisance fruit on sweet gum and ginkgo with ethephon. Proc N Central Weed Sci Soc, 5–7 December 1995, Omaha, Nebraska, USA. 50: 1–53.Google Scholar
  41. Donald, C.M., 1968. The breeding of crop ideotypes. Euphytica 17: 385–403.CrossRefGoogle Scholar
  42. Dotson, S.B., M. Lanahan, A.G. Smith & G. Kishore, 1996. A phosphonate monoester hydrolase from Burkholderia caryophilli PG2982 is useful as a conditional lethal gene in plants. Plant J 10: 383–392.PubMedCrossRefGoogle Scholar
  43. Egolf, D.R., 1970. Hibiscus syriacus ‘Diana ’, a new cultivar [Malvaceae]. Baileya 17: 75–78.Google Scholar
  44. Egolf, D.R., 1981. ‘Helene Rose of Sharon (Althea). HortScience 16: 226–227.Google Scholar
  45. Egolf, D.R., 1986. ‘Minerva Rose of Sharon (Althea). HortScience 21: 1463–1464.Google Scholar
  46. Egolf, D.R., 1988. ‘Aphrodite Rose of Sharon (Althea). HortScience 23: 223.Google Scholar
  47. Eis, S., E.H. Garman & L.F. Ebell, 1965. Relation between cone production and diameter increment of Douglas fir (Pseudotsuga menziesii [Mirb.] Franco), grand fir (Abies grandis [Doug.] Lindl., and western white pine (Pinus monticola Dougl.). Can J Bot 43: 1553–1559.CrossRefGoogle Scholar
  48. Ellstrand, N.C. & C.A. Hoffman C.A, 1990. Hybridisation as an avenue of escape for engineered genes. BioScience 40: 438–442.CrossRefGoogle Scholar
  49. Erdelska, O. & S. Budikova, 2002. “Non-flowering” apple mutant of Fandly in the centre of interest again. Acta-Horticulturae-et-Regiotecturae (Slovak Republic). Sci J Hort Landscape Eng Architect Ecol 5(1): 7–8.Google Scholar
  50. Estrada, S., M.A. Mutschler & F.A. Vliss, 1984. Temperature-influenced instability in a genic male-sterile common bean. HortScience 19: 401–402.Google Scholar
  51. Flaschenriem, D.R. & P.D. Ascher, 1979. S allele discrimination in styles of Petunia hybrida bearing stylar-conditioned pseudo-self compatibility. Theor Appl Genet 55: 23–28.CrossRefGoogle Scholar
  52. Gift, E.A., H.J. Park, G.A. Paradis, A.L. Demain & J.C. Weaver, 1996. FACS-based isolation of slowly growing cells: Double encapsulation of yeast in gel microdrops. Nat Biotechnol 14(7): 884–887.PubMedCrossRefGoogle Scholar
  53. Goldsmith Seed Co., 1999. Goldsmith Seeds from a to z. Goldsmith Seed Company, Gilroy, California.Google Scholar
  54. Gray, A., 1993. The vascular plant pioneers of primary successions: Persistence and phenotypic plasticity. In: J. Miles & D. Walton (Eds.), Primary Succession on Land, pp. 179–191. Blackwell, Oxford.Google Scholar
  55. Gray, J. (Ed.), 2003. Programmed cell death in plants. Blackwell, Oxford.Google Scholar
  56. Halsted, B.D. & E.J. Owen, 1917. Influence of position of grain on the cob on the growth of maize seedlings. Agronomy J 9(6): 267–274.CrossRefGoogle Scholar
  57. Harlan, R., 1966. Plant introduction and biosystematics. In: K.J. Frey (Ed.), Plant Breeding: A Symposium Held at Iowa State University, pp. 55–84. The Iowa State University Press, Ames, Iowa.Google Scholar
  58. Hawkes, J.G. & M.T. Jackson, 1992. Taxonomic and evolutionary implications of the endosperm balance number hypothesis in potatoes. Theor Appl Genet 84(1/2): 180–185.Google Scholar
  59. Hector, A., K. Dobson, A. Minns, E. Bazeley-White & J.H. Lawton, 2001. Community diversity and invasion resistance: An experimental test in a grassland ecosystem and a review of comparable studies. Ecol Res 16(5): 819–831.CrossRefGoogle Scholar
  60. Hutchinson, T.F. & J.L. Vankat, 1997. Invasibility and effects of Amur Honeysuckle in southwestern Ohio forests. Con Biol 11: 1117–1124.CrossRefGoogle Scholar
  61. Jablonski, B., 1986. Pollination and yielding of 15 varieties of lucerne depending on abundance of blooming and nectar secretion. Pszczelnicze-Zeszyty-Naukowe (Poland) 30: 207–220.Google Scholar
  62. Keeley, S.C., J.E. Keeley, S.M. Hutchinson & A.W. Johnson, 1981. Postfire succession of the herbaceous flora in southern California Chaparral. Ecology 62: 1608–1621.CrossRefGoogle Scholar
  63. Kempthorne, O., 1957. An Introduction to genetic statistics. Wiley, New York.Google Scholar
  64. Kennard, W.C., R.L. Phillips & R.A. Porter, 2002. Genetic dissection of seed shattering, agronomic, and color traits in American wildrice (Zizania palustris var. interior L.) with a comparative map. Theor Appl Genet 105(6/7): 1075–1086.PubMedGoogle Scholar
  65. Klimes, L., J. Klimesova, R. Hendriks & J.M. van Groenendael, 1997. Clonal plant architecture: A comparative analysis of form and function. In: H. de Kroon & J.M. van Groenendael (Eds.), The Ecology and Evolution of Clonal Plants, pp. 1–29. Backhuys, Leiden, The Netherlands.Google Scholar
  66. Klinger, T., P.E. Arriola & N.C. Ellstrand, 1992. Crop-weed hybridization in radish (Raphanus sativus): Effects of distance and population size. Am J Bot 79: 1431–1435.CrossRefGoogle Scholar
  67. Kristiansen, K., 1994. Breeding and clonal variation in Miscanthus. SP Rapport, No. 16, pp. 47–51.Google Scholar
  68. Krumfolz, L.A. & S.B. Wilson, 2002. Varying growth and sexual reproduction across cultivars of Ruellia brittoniana. Proc South Nursery Assoc 47: 99–102.Google Scholar
  69. Langeland, K.A., 2002. Natural area weeds: Old World climbing fern (Lygodium microphyllum). University of Florida Extension, Institute of Food & Agricultural Sciences, Document SS-AGR-21. 4 pp.Google Scholar
  70. Langton, F.A. & K.E. Cockshull, 1979. Screening chrysanthemums for leaf number in long days. Research Report, 1978, pp. 177–186. Glasshouse Crops Res. Inst., Littlehampton, Sussex, UK.Google Scholar
  71. Lerch, V. & A. Dudzinski, 1992. Phenotypic and isozyme diversity in an Impatiens germplasm collection. Department of Horticulture, University of Maryland at College Park.Google Scholar
  72. Levings, C.S.M., 1990. The Texas cytoplasm of maize: Cytoplasmic male sterility and disease susceptibility. Science 250: 942–947.PubMedGoogle Scholar
  73. Lewandowski, I., J.C. Clifton-Brown, J.M.O. Scurlock & W. Huisman, 2000. Miscanthus: European experience with a novel energy crop. Biomass Bioenerg 19: 209–227.CrossRefGoogle Scholar
  74. Liedl, B.E. & N.O. Anderson, 1993. Reproductive barriers: Identification, uses, and circumvention. Plant Breed Rev 11: 11–154.Google Scholar
  75. Lindstrom, J.Y., G.T. Bujarski, M.J. Love & B.M. Burkett, 2002. Buddleja breeding at the University of Arkansas. Proc South Nursery Assoc 47: 630–633.Google Scholar
  76. Luken, J.O. & B. Goessling, 1995. Seedling distribution and potential persistence of the exotic shrub Lonicera maackii in the fragmented forests. Am Midland Nat 133: 124–130.CrossRefGoogle Scholar
  77. Mendel, G., 1865. Versuche über Pflanzen-Hybriden. Verhandlungen des naturforschenden Vereines in Brünn 4: 3–47.Google Scholar
  78. Meyer, M.H., D.B. White & H. Pellett, 1994. Ornamental grasses for Minnesota. J Env Hort 12(3): 159–163.Google Scholar
  79. Mickelson, H.C., 1992. Congruity backcrossing as a method of establishing multi-species gene pools in Phaseolus. M.S. Thesis, University of Minnesota, St. Paul.Google Scholar
  80. Moody, M.L. & D.H. Les, 2002. Evidence of hybridity in invasive watermilfoil (Myriophyllum) populations. Proc Natl Acad Sci USA 999: 14867–14871.CrossRefGoogle Scholar
  81. Moreira, I., 1975. Propagacao por semente do Cynodon dactylon (L.) Pers. Anais do Instituto Superior de Agronomia 35: 95–112.Google Scholar
  82. Muller, H.J., 1964. The relation of recombination to mutational advantage. Mutat Res 1: 2–9.Google Scholar
  83. Ogren, T., 2003. Allergy reduction benefits of pollenless landscape plants. In: Meeting Summary, Modifying Reproduction in Urban Trees, Feb. 12–13, 2003, p. 7–9. North Carolina Biotechnology Center.Google Scholar
  84. Ori, N., G. Sessa, T. Lotan, S. Himmelhoch & R. Fluhr, 1990. A major stylar matrix polypeptide (sp41) is a member of the pathogenesis-related proteins superclass. EMBO J 9: 3429–3436.PubMedGoogle Scholar
  85. PanAmerican Seed Company, 1999. 1999 Product information guide. PanAmerican Seed, W. Chicago, IL.Google Scholar
  86. Parker, I.M., 2000. Invasion dynamics of Cytisus scoparius: A matrix model approach. Ecol Appl 10: 726–743.Google Scholar
  87. Perry, N.B., A.J. Baxter, N.J. Brennan, J.W. van Klink, J.A. McGimpsey, M.H. Douglas & D. Joulain, 1996. Dalmatian sage. Part 1. Differing oil yields and compositions from flowering and non-flowering accessions. Flav Fragr J (UK) 11(4): 231–238.CrossRefGoogle Scholar
  88. Peterson, C.E. & R.L. Foskett, 1953. Occurrence of pollen sterility in seed fields of scott county globe onions. Proc Am Soc Hort Sci 62: 443–448.Google Scholar
  89. Phillips, G., A.X. Niemiera & R. Harris, 2004. Developing invasive plant criteria: An industry proactive approach. Perennial Plants, Spr: 12–44.Google Scholar
  90. Pluess, A.R. & J. StHocklin, 2005. The importance of population origin and environment on clonal and sexual reproduction in the alpine plant Geum reptans. Funct Ecol 19: 228–237.CrossRefGoogle Scholar
  91. Proven Winners, 2004. Spring collection 2005. Proven Winners, Sycamore, Illinois.Google Scholar
  92. Ramanna, M.S., 1992. The role of sexual polyploidization in the origins of horticultural crops: Alstroemeria as an example. In: A. Mariani & S. Tavoletti (Eds.), Gametes with Somatic Chromosome Number in the Evolution and Breeding of Polyploid Polysomic Species: Achievements and Perspectivesm, pp. 83–90. Tipolitografia Porziuncola, Assisi, Italy.Google Scholar
  93. Raybould, A.F. & A.J. Gray, 1994. Will hybrids of genetically modified crops invade natural communities? Trends Ecol Evol 9: 85–88.CrossRefGoogle Scholar
  94. Raymer, J. & M. Thetford, 2002. Genetic diversity among red leaf and green leaf Imperata cylindrica. Proc South Nursery Assoc 47: 656–660.Google Scholar
  95. Reichard, S.H. & P. White, 2001. Horticulture as a pathway of invasive plant introductions in the United States. Bioscience 51(2): 103–113.Google Scholar
  96. Robacker, C.D. & P.D. Ascher, 1982. Effect of selection for pseudo-self compatibility in advanced inbred generations of Nemesia strumosa Benth. Euphytica 31: 591–601.CrossRefGoogle Scholar
  97. Sakata Seed Co., 1999–2000. Flower Seed Catalog. Sakata Seed Co., Yokohama, Japan.Google Scholar
  98. Sessa, G. & R. Fluhr, 1995. The expression of an abundant transmitting tract-specific endoglucanase (SP41) is promoter-dependent and not essential for the reproductive physiology of tobacco. Plant Molec 29: 969–982.CrossRefGoogle Scholar
  99. Sheppard, A.W., P. Hodge, Q. Paynter, & M. Rees, 2002. Factors affecting invasion and persistence of broom Cytisus scoparius in Australia. J Appl Ecol 39: 721–734.CrossRefGoogle Scholar
  100. Smith, A.G., C. S. Gasser, K.A. Budelier & R.T. Fraley, 1990. Identification and characterization of stamen- and tapetal-specific genes from tomato. Mol Gen Genet 222: 9–16.PubMedGoogle Scholar
  101. Smith, D.C., 1966. Plant breeding ‘ Development and success. In: K.J. Frey (Ed.), Plant breeding: A Symposium Held at Iowa State University, pp. 3–54. The Iowa State University Press, Ames, Iowa.Google Scholar
  102. Solecki, M.K., 1989. The viability of cut-leaved teasel (Dipsacus laciniatus L.) seed harvested from flowering stems ‘ management implications. Nat Areas J 9: 102–105.Google Scholar
  103. Stewart, J.R. & W.R. Graves, 2004. Photosynthesis and growth of Rhamnus caroliniana during drought and flooding: Comparisons to the invasive Rhamnus cathartica. HortScience 39(6): 1278–1282.Google Scholar
  104. Still, S.M., 1994. Manual of herbaceous ornamental plants. Stipes Publishing, Champaign, IL.Google Scholar
  105. Strauss, S., 2003. Meeting rationale, structure, and goals. In: Meeting Summary, Modifying Reproduction in Urban Trees, Feb. 12–13, 2003, p. 4. North Carolina Biotechnology Center.Google Scholar
  106. Strauss, S., W.H. Rottmann, A.M. Brunner & L.A. Sheppard, 1995. Genetic engineering of reproductive sterility in forest trees. Molec Breed 1: 5–26.CrossRefGoogle Scholar
  107. Than, M.E., M. Helm & D.J. Simpson, 2004. The 2.0 A crystal structure and substrate specificity of the KDEL-tailed cysteine endopeptidase functioning in programmed cell death of Ricinus communis endosperm. J Mol Biol 336(5): 1103–1116.PubMedCrossRefGoogle Scholar
  108. Thomas, S.G. & V.E. Franklin-Tong, 2004. Self-incompatibility triggers programmed cell death in Papaver pollen. Nature 429: 305–309.PubMedCrossRefGoogle Scholar
  109. van Gaal, T., S.M. Galatowitsch & M. Strefeler, 1998. Ecological consequences of hybridization between a wild species (Echinacea purpurea) and a related cultivar (E. purpurea ‘White Swan ’). Sci Hort 76: 73–88.CrossRefGoogle Scholar
  110. W. Atlee Burpee & Co., 2005. Burpee Gardening 2005 Catalog. Warminster, Pennsylvania.Google Scholar
  111. Walters Garden, Inc., 2004. Welcome to Walter's Garden, Inc.
  112. Warren, K., 2003. The nursery perspective on the economic and environmental benefits of biotech sterile trees. In: Meeting Summary, Modifying Reproduction in Urban Trees, Feb. 12–13, 2003, pp. 4–6. North Carolina Biotechnology Center.Google Scholar
  113. Weddle, C., 1965. New flowers by new methods. Horticulture, January 1965, pp. 18–19, 48–49.Google Scholar
  114. Weiss, M.R., 1991. Floral colour changes as cues for pollinators. Nature 354: 227–229.CrossRefGoogle Scholar
  115. Welling, C.H. & R.L. Becker, 1993. Reduction of purple loosestrife establishment in minnesota wetlands. Wildlife Soc Bull 21: 56–64.Google Scholar
  116. Wheeler, A.R. & M.C. Starrett, 2001. Determining the invasive potential of Rhamnus frangula ‘Asplenifolia (Cutleaf Buckthorn) and Rhamnus frangula ‘Columnaris (Columnar Buckthorn) based on seed germination. HortScience 36(3): 515.Google Scholar
  117. Widmer, R.E., 1958. The determination of cold resistance in the garden chrysanthemum and its relation to winter survival. Proc Am Soc Hort Sci 71: 537–546.Google Scholar
  118. Wood, T., 2004. Growing solutions to the invasive plant problem. Perennial Plants, Spring Issue, pp. 42–44.Google Scholar
  119. Yamada, T. & M. Wataru, 2003. Overproduced ethylene causes programmed cell death leading to temperature-sensitive lethality in hybrid seedlings from the cross Nicotiana suaveolens × N. tabacum. Planta 217(5): 690–698.PubMedCrossRefGoogle Scholar

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© Springer Science + Business Media, Inc. 2006

Authors and Affiliations

  • N. O. Anderson
    • 1
    Email author
  • N. Gomez
    • 1
  • S. M. Galatowitsch
    • 1
  1. 1.Department of Horticultural ScienceUniversity of MinnesotaSt. PaulUSA

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