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): Constance I. Millar
    Date: 1985
    Source: Ph.D. dissertation. University of California.
    Publication Series: Dissertations
    Station: Pacific Southwest Research Station
    PDF: Download Publication  (3.0 MB)


    Reported here are the results of studies on the unusually abrupt genetic transition that occurs in several traits in continuous bishop pine stands of northern Sonoma County, California. The genetic nature of this anomalous cline was investigated using allozyme, common garden, crossability, and controlled-soil analyses. Data from these analyses allowed a preliminary interpretation on the evolutionary relationships of the pines of this region.

    Initially, seeds were collected from 78 green foliaged trees in 8 stands south of the transition at Sea Ranch, from 27 blue, green or intermediate foliaged trees in 3 transition stands, and from 96 blue foliaged trees in 8 stands north of Sea Ranch. Allozyme frequencies in maternal trees of alleles at one locus (Got2) differed significantly between the blue population (average frequency of allele 1, .96) and green population (average frequency of allele 1, .24). The frequencies changed over 2 km in a steep cline at Sea Ranch that coincided with the transition in foliage color.

    The Got2 allele frequencies in the pollen grains that effected fertilization of the analysed seeds differed significantly from maternal allele frequencies in green stands south of Sea Ranch. The frequencies differed in a pattern that suggested unidirectional gene flow via pollen from north (blue) to south (green): south of Sea Ranch, the frequency of Gotl was lower in pollen than in maternal trees. The gene flow explanation was corroborated by the north-northwestern direction of prevailing winds along the coast during the pollination season.

    Publication Notes

    • You may send email to 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.


    Millar, Constance I. 1985. Genetic studies of dissimilar parapatric populations in northern bishop pine (Pinus muricata). Berkeley, CA: University of California. 198 p. Ph.D. dissertation.

    Related Search

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