Australian Journal of Botany Australian Journal of Botany Society
Southern hemisphere botanical ecosystems

Gene flow between introduced and native Eucalyptus species: crossability of native Tasmanian species with exotic E. nitens

R. C. Barbour A B , B. M. Potts A and R. E. Vaillancourt A
+ Author Affiliations
- Author Affiliations

A Cooperative Research Centre for Sustainable Production Forestry and School of Plant Science, University of Tasmania, Private Bag 55, Hobart, Tas. 7001, Australia.

B Corresponding author. Email:

Australian Journal of Botany 53(5) 465-477
Submitted: 8 February 2005  Accepted: 20 May 2005   Published: 11 August 2005


Eucalyptus nitens (Deane & Maiden) Maiden has been extensively introduced to the island of Tasmania for plantation purposes. Natural hybridisation with two native species has already been confirmed and this study aimed to determine which other Tasmanian native species could potentially hybridise with E. nitens. Controlled and supplementary pollinations with E. nitens pollen were undertaken on all Tasmanian native species that are potentially at risk of exotic gene flow and hence genetic pollution. Across the seven species tested by using controlled pollinations, seed set per flower, following E. nitens pollinations, was significantly less than for intraspecific outcross pollinations. No significant differences were evident in the percentage of seed that germinated or the percentage of germinants that grew into healthy seedlings in the glasshouse. Hybridity was verified by morphometric analyses and F1 hybrid seedlings were clearly differentiated from parental species and generally intermediate in morphology. Supplementary E. nitens pollination of open-pollinated native flowers was conducted to simulate natural pollination where pollen competition would occur. Seven of the fifteen species tested produced F1 hybrids in this case; however, further crossing is required to verify failed cross combinations. Although E. nitens can potentially hybridise with many native species, the results from both supplementary and controlled pollinations suggest the presence of post-pollination barriers of varying strength that need to be considered in assessing the risk of exotic gene flow from plantations.


The authors thank the Australian Research Council, Gunns Limited and Forestry Tasmania for financial and/or technical support.


Anttila CK, Daehler CC, Rank NE, Strong DR (1998) Greater male fitness of a rare invader (Spartina alterniflora, Poaceae) threatens a common native (Spartina foliosa) with hybridization. American Journal of Botany 85, 1597–1601.

Arnold, ML (1997). ‘Natural hybridization and evolution.’ (Oxford University Press: Oxford)

Baltazar MB, Sánchez-Gonzalez JJ, Cruz-Larios L, Schoper JB (2005) Pollination between maize and teosinte: an important determinant of gene flow in Mexico. Theoretical and Applied Genetics 110, 419–526.
CrossRef |

Barbour RC (2004) Gene flow from introduced Eucalyptus plantations into native eucalypt species. PhD Thesis (University of Tasmania: Hobart)

Barbour RC, Potts BM, Vaillancourt RE (2003) Gene flow between introduced and native Eucalyptus species: exotic hybrids are establishing in the wild. Australian Journal of Botany 51, 429–439.
CrossRef |

Barbour RC, Potts BM, Vaillancourt RE (2005) Pollen dispersal from exotic eucalypt plantations. Conservation Genetics 6, 253–257.
CrossRef |

Barbour RC, Potts BM, Vaillancourt RE, Tibbits WN, Wiltshire RJE (2002) Gene flow between introduced and native Eucalyptus species. New Forests 23, 177–191.
CrossRef |

Brooker MIH (2000) A new classification of the genus Eucalyptus L’Her. (Myrtaceae). Australian Systematic Botany 13, 79–148.
CrossRef |

Brown AHD, Brubaker CL (2000) Genetics and the conservation and use of Australian wild relatives of crops. Australian Journal of Botany 48, 297–303.
CrossRef |

Brown, AHD , Brubaker, CL ,  and  Kilby, MJ (1997). Assessing the risk of cotton transgene escape into wild Australian Gossypium species. In ‘Commercialisation of transgenic crops: risk, benefit and trade considerations’. pp. 83–94. (Bureau of Resource Sciences: Canberra)

Cauvin, B , Potts, BM ,  and  Potts, WC (1987). Eucalyptus: Hybridation artificielle—barrières et hérédité des caracteres. In ‘Annales de recherches sylvicoles’. pp. 255–303. (Association Forêt-Cellulose: Paris)

Commonwealth of Australia (1998) ‘A framework of regional (sub-national) level criteria and indicators of sustainable forest management in Australia.’ (Department of Agriculture, Fisheries and Forestry: Canberra)

Commonwealth of Australia (2003) ‘The Australian forestry standard.’ (Australian Forestry Standard Project Office: Canberra)

Delaporte KL, Conran JG, Sedgley M (2001a) Interspecific hybridization between three closely related ornamental Eucalyptus species: E. macrocarpa, E. youngiana and E. pyriformis.  Journal of Horticultural Science & Biotechnology 76, 384–391.

Delaporte KL, Conran JG, Sedgley M (2001b) Interspecific hybridization within Eucalyptus (Myrtaceae): subgenus Symphyomyrtus, sections Bisectae and Adnataria.  International Journal of Plant Sciences 162, 1317–1326.
CrossRef |

Delaporte KL, Conran JG, Sedgley M (2001c) Morphological analysis to identify the pollen parent of an ornamental interspecific hybrid Eucalyptus.  Scientia Horticulturae 89, 57–72.
CrossRef |

Drake DW (1975) Seed abortion in some species and interspecific hybrids of Eucalyptus.  Australian Journal of Botany 23, 991–995.

Drake, JA , Mooney, HA , di Castri, F , Groves, RH , Kruger, FJ , Rejanek, M ,  and  Williamson, M (1989). ‘Biological invasions: a global perspective.’ (John Wiley and Sons: Brisbane)

Ellis MF, Sedgley M, Gardner JA (1991) Interspecific pollen-pistil interaction in Eucalyptus L’Her. (Myrtaceae): the effect of taxonomic distance. Annals of Botany 68, 185–194.

Ellstrand NC (1992) Gene flow by pollen: implications for plant conservation genetics. Oikos 63, 77–86.

Espejo, J , Hernández, V , Sierra, V , Bacerra, J ,  and  López, R (2004). Determination of terpenes through gas chromatography–mass spectrometry (GC–MS): a new tool in the early determination of hybrid progenies of Eucalyptus nitens × E. globulus. In ‘Proceedings of the international IUFRO conference ‘ in a changing world’ on silviculture and improvement of eucalypts’. Aveiro, Portugal. (RAIZ—Instituto de Investigação da Floresta e Papel: Eixo, Portugal)

Espejo, JE , England, NF ,  and  Griffin, AR (1995). Results of a crossing program with Eucalyptus nitens and E. globulus in Chile. In ‘Proceedings of the CRCTHF–IUFRO conference on eucalypt plantations: improving fibre yield and quality’, Hobart, Tasmania. pp. 239–240. (CRC for Temperate Hardwood Forestry: Hobart)

Gore PL, Potts BM, Volker PW, Megalos J (1990) Unilateral cross-incompatibility in Eucalyptus: the case of hybridisation between E. globulus and E. nitens.  Australian Journal of Botany 38, 383–394.

Griffin AR, Burgess IP, Wolf L (1988) Patterns of natural and manipulated hybridisation in the genus Eucalyptus L’Herit.—a review. Australian Journal of Botany 36, 41–66.

Hoffman CA (1990) Ecological risks of genetic engineering of crop plants. Bioscience 40, 434–437.

Jana S, Nevo E (1991) Variation in response to infection with Erysiphe graminis hordei and Puccinia hordei in some wild barley populations in a centre of diversity. Euphytica 57, 133–140.
CrossRef |

Klips RA (1999) Pollen competition as a reproductive isolating mechanism between two sympatric Hibiscus species (Malvaceae). American Journal of Botany 86, 269–272.

Levin DA (1978) The origin of isolating mechanisms in flowering plants. Evolutionary Biology 11, 185–317.

Levin DA, Francisco-Ortega J, Jansen RK (1996) Hybridization and the extinction of rare plant species. Conservation Biology 10, 10–16.
CrossRef |

Lopez GA, Potts BM, Tilyard PA (2000) F1 hybrid inviability in Eucalyptus: the case of E. ovata × E. globulus.  Heredity 85, 242–250.
CrossRef | PubMed |

Meddings RA, McComb JA, Calver MC, Thomas SR, Mazanec RA (2003) Eucalyptus camaldulensis × globulus hybrids. Australian Journal of Botany 51, 319–331.
CrossRef |

Moncur, MW (1995). ‘Techniques for pollinating eucalypts.’ (Australian Centre for International Agricultural Research: Canberra)

National Forest Inventory (2004) National plantation inventory update—March 2004. Bureau of Rural Sciences, Canberra.

Nevo E (1998) Genetic diversity in wild cereals: regional and local studies and their bearing on conservation ex situ and in situ. Genetic Resources and Crop Evolution 45, 355–370.
CrossRef |

Patterson B, Gore P, Potts BM, Vaillancourt RE (2004) Advances in pollination techniques for large-scale seed production in Eucalyptus globulus.  Australian Journal of Botany 52, 781–788.
CrossRef |

Pederick LA (1979) Natural variation in shining gum (Eucalyptus nitens). Australian Forest Research 9, 41–63.

Potts BM, Dungey HD (2004) Hybridisation of Eucalyptus: key issues for breeders and geneticists. New Forests 27, 115–138.
CrossRef |

Potts BM, Marsden-Smedley JB (1989) In vitro germination of Eucalyptus pollen: response to variation in boric acid and sucrose. Australian Journal of Botany 37, 429–441.

Potts BM, Reid JB (1988) Hybridisation as a dispersal mechanism. Evolution 42, 1245–1255.

Potts BM, Reid JB (1990) The evolutionary significance of hybridisation in Eucalyptus.  Evolution 44, 2151–2152.

Potts, BM , Volker, PW ,  and  Dungey, HS (1992). Barriers to the production of interspecific hybrids in Eucalyptus. In ‘Proceeding of the AFOCEL–IUFRO symposium on mass production technology for genetically improved fast growing forest tree species’, Bordeaux. pp. 193–204. (Association Forêt Cellulose: Nangis, France)

Potts BM, Barbour RC, Hingston AB, Vaillancourt RE (2003) Turner review: the risks of genetic pollution of native eucalypt gene pools. Australian Journal of Botany 51, 1–25.
CrossRef |

Pryor, LD (1976). ‘Biology of eucalypts.’ (Edward Arnold: London)

Ramsey J, Bradshaw HD, Schemske DW (2003) Components of reproductive isolation between the monkey flowers Mimulus lewisii and M. cardinalis (Phrymaceae). Evolution 57, 1520–1534.
PubMed |

Raybould AF, Gray AJ (1994) Will hybrids of genetically modified crops invade natural communities? Trends in Ecology & Evolution 9, 85–89.
CrossRef |

Rhymer JM, Simberloff D (1996) Extinction by hybridisation and introgression. Annual Review of Ecology and Systematics 27, 83–109.
CrossRef |

Schierenbeck KA, Symonds VV, Gallagher KG, Bell J (2005) Genetic variation and phylogeographic analyses of two species of Carpobrotus and their hybrids in California. Molecular Ecology 14, 539–547.
CrossRef | PubMed |

Sedgley M, Granger L (1996) Embryology of Eucalyptus spathulata and E. platypus (Myrtaceae) following selfing, crossing and reciprocal interspecific pollination. Australian Journal of Botany 44, 661–671.

Steane DA, Byrne M, Vaillancourt RE, Potts BM (1998) Chloroplast DNA polymorphism signals complex interspecific interactions in Eucalyptus (Myrtaceae). Australian Systematic Botany 11, 25–40.
CrossRef |

Strauss SY (2001) Benefits and risks of biotic exchange between Eucalyptus plantations and native Australian forests. Austral Ecology 26, 447–457.
CrossRef |

Tibbits WN (1988) Germination and morphology of progeny from controlled pollinations of Eucalyptus nitens (Deane & Maiden) Maiden. Australian Journal of Botany 36, 677–691.

Tibbits WN (1989) Controlled pollination studies with shining gum (Eucalyptus nitens (Deane & Maiden) Maiden). Forestry 62, 111–126.

Tibbits, WN (2000). Evaluation of hybrids with Eucalyptus nitens. In ‘Proceedings of QFRI/CRC–SPF symposium on hybrid breeding and genetics of forest trees’, Noosa, Australia. pp. 363–372. (Department of Primary Industries: Brisbane)

Vanden Broeck A, Quataert P, Roldan-Ruiz I, Van Bockstaele E, Van Slycken J (2003) Pollen competition in Populus nigra females revealed by microsatellite markers. Forest Genetics 10, 219–227.

Vila M, Weber E, Antonio CMD (2000) Conservation implications of invasion by plant hybridization. Biological Invasions 2, 207–217.
CrossRef |

Wardell-Johnson, G , Williams, JE , Hill, K ,  and  Cumming, R (1997). Evolutionary biogeography and contemporary distribution of Eucalyptus. In ‘Eucalypt ecology: individuals to ecosystems’. pp. 92–128. (Cambridge University Press: Cambridge, UK)

Whitham TG, Young WP, Martinsen GD, Gehring CA, Schweitzer JA, Shuster SM, Wimp GM, Fischer DG, Bailey JK, Lindroth RL, Woolbright S, Kuske CR (2003) Community and ecosystem genetics: a consequence of the extended phenotype. Ecology 84, 559–573.

Wiersma PA (2003) Reproductive barriers in tree fruit crops and nuts. Genetics and Breeding of Tree Fruits and Nuts 622, 369–377.

Williams DR, Potts BM, Black PG (1999) A single visit pollination method for Eucalyptus globulus.  Australian Forestry 62, 346–352.

Williams JH, Boecklen WJ, Howard DJ (2001) Reproductive processes in two oak (Quercus) contact zones with different levels of hybridization. Heredity 87, 680–690.
CrossRef | PubMed |

Williams K, Potts BM (1996) The natural distribution of Eucalyptus species in Tasmania. Tasforests 8, 39–165.

Wiltshire RJE, Reid JB (1987) Genetic variation in the Spinning Gum, Eucalyptus perriniana F.Muell. ex Rodway. Australian Journal of Botany 35, 33–47.

Wood, MS , Stephens, NC , Allison, BK ,  and  Howell, CI (2001). Plantations of Australia—a report from the National Plantation Inventory and the National Farm Forest Inventory. (Bureau of Rural Sciences: Canberra)

Yawen Z W, Wang JJ, Yang ZY, Shen SQ, Wu LH, Chen XY, Meng JG (2001) The diversity and sustainable development of crop genetic resources in the Lancang River Valley. Genetic Resources and Crop Evolution 48, 297–306.
CrossRef |

Rent Article (via Deepdyve) Supplementary MaterialSupplementary Material (95 KB) Export Citation Cited By (13)