Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Jill A. Hamilton; Jessica W. Wright; F. Thomas Ledig
    Date: 2017
    Source: In: Sniezko, Richard A.; Man, Gary; Hipkins, Valerie; Woeste, Keith; Gwaze, David; Kliejunas, John T.; McTeague, Brianna A., tech. cords. 2017. Gene conservation of tree species—banking on the future. Proceedings of a workshop. Gen. Tech. Rep. PNW-GTR-963. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. p. 75.
    Publication Series: General Technical Report (GTR)
    Station: Pacific Northwest Research Station
    PDF: View PDF  (32.0 KB)

    Description

    Torrey pine (Pinus torreyana) is one of the rarest pine species in the world. Restricted to one mainland and one island population in California, Torrey pine is a species of conservation concern under threat due to low population sizes, lack of genetic variation, and environmental stochasticity. Previous research points to a lack of within population variation that is unprecedented among conifer species, although a few fixed genetic differences between the populations contribute to subspecies classification. Given this, development of best conservation practices requires a combination of genetic and trait evaluation tools to conserve this keystone species. To evaluate phenotypic differences between populations, a provenance trial was established in 2007 at the Santa Barbara Botanic Garden. The trial consists of seeds established from cones collected within a mainland progeny trial of mainland and island individuals and includes mainland, island, and hybrid individuals, the result of natural hybridization within the progeny trial. Genetic ancestry of individuals was evaluated using allozyme markers as fixed genetic differences were observed between populations. We evaluated phenotypic differences between mainland, island and hybrid individuals, comparing early germination traits and annual fitness metrics height and fecundity following establishment. Preliminary results indicate admixed individuals exhibit increased fitness relative to mainland and island individuals at all development stages, suggesting a potential role for genetic rescue via intraspecific hybridization in this genetically depauperate species. However, unidirectional hybridization within the F1s indicates extrinsic or intrinsic barriers to reproduction have evolved between these populations, indicating between-population crosses may not represent a viable option to conserve evolutionary potential. This long term dataset provides an invaluable resource to test predictions regarding the use of genetic rescue in rare, long-lived species.

    Publication Notes

    • You may send email to pnw_pnwpubs@fs.fed.us to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

    Citation

    Hamilton, Jill A.; Wright, Jessica W.; Ledig, F. Thomas. 2017. Genetic conservation and management of the Californian endemic, Torrey Pine (Pinus torreyana Parry). In: Sniezko, Richard A.; Man, Gary; Hipkins, Valerie; Woeste, Keith; Gwaze, David; Kliejunas, John T.; McTeague, Brianna A., tech. cords. 2017. Gene conservation of tree species—banking on the future. Proceedings of a workshop. Gen. Tech. Rep. PNW-GTR-963. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. p. 75.

    Related Search


    XML: View XML
Show More
Show Fewer
Jump to Top of Page