Skip to page content
USDA Forest Service

Research & Development Treesearch

Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Pacific Northwest
Pacific Southwest
Rocky Mountain

GeoTreesearch - We Participate  Government Made Easy

Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

(575 KB bytes)

Title: Crossability and relationships of Pinus muricata (Pinaceae)

Author: Millar, Constance I.; Critchfield, William B.

Date: 1988

Source: Madroño Vol. 35(1): p. 39-53

Publication Series: Not categorized

Description: Crossing relationships were studies within and among the variable populations of Pinus muricata to test hypotheses about crossing barriers among certain populations. Crossability was assessed at the level of viable seed production following planned crosses. Populations north of Sea Ranch, Sonoma Co., California, crossed freely with parapatric but genetically distinct populations in central Sonoma Co., although some reduction in seed-set occurred in the F2 and backcrosses to F1. The distinctness of these adjacent poulations is most likely not maintained by post-pollination crossing barriers. Crossability of disjunct P. muricata populations generally decreased with distance between populations. populations north of Sea Ranch crossed freely with the Pt. Reyes poulation in Marin Co., less readily with the Monterey population, and not at all with the Purisima (southern California) or Baja California populations. Mainland and island P. muricata populations south of Monterey were highly interfertile. Test crosses were also attempted between P. muricata and the island populations of P. radiata,which have been considered closely related to southern P. muricata populations. Pinus muricata from Baja California did not cross, however, with either Guadalupe Island pine (P. radiata var. binata) or Cedros Island pine (P. radiata var. cedrosensis). Together with results from other crossing studies in the Californian closed-cone pines, the patterns of crossability indicate three crossing units in P. muricata: 1)northern P. muricata populations from Marin Co. northward, which are reproductively isolated from, 2)southern P. muricata populations including mainland and Channel Island populations from Purisima southward, and 3)Monterey P. muricata, which is intermediate between the first two units.

Publication Notes:

  • 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.; Critchfield, William B. 1988. Crossability and relationships of Pinus muricata (Pinaceae). Madroño Vol. 35(1): p. 39-53


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.