Occurrence, structure, and nitrogen-fixation of root nodules of actinorhizal Arizona alder

This article is part of a larger document. View the larger document here.

  • Authors: Dawson, J. O.; Gottfried, Gerald J.; Hahn, D.
  • Publication Year: 2005
  • Publication Series: Proceedings (P)
  • Source: In: Gottfried, Gerald J.; Gebow, Brooke S.; Eskew, Lane G.; Edminster, Carleton B., comps. Connecting mountain islands and desert seas: biodiversity and management of the Madrean Archipelago II. Proc. RMRS-P-36. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 75-79

Abstract

Actinorhizal plants are nodulated by the symbiotic, nitrogen-fixing actinomycete Frankia. The genus Alnus in the family Betulaceae is one of the 24 genera in 8 families of angiospermous plants that are actinorhizal. Arizona alder (Alnus oblongifolia Torr.) occurs in isolated populations associated with the watersheds of Madrean Sky Islands in the Southwestern United States between 1,370 and 2,285 m in elevation. We have found root nodules on alder trees from Oak Creek Canyon in central Coconino County, Arizona, and from the Santa Catalina Mountains in southeastern and central Pima County, Arizona. We describe the occurrence of nodules at two locations at or near opposite latitudinal limits of Arizona alder’s main range. Capacity of Arizona alder nodules to fix atmospheric nitrogen is confirmed by the acetylene reduction assay and the occurrence of vesicles in infected cortical cells of nodule lobes. Nodule location on roots, nodule morphology, and cellular anatomy confirm symbiotic structure similar to that of other alder species.

  • Citation: Dawson, J. O.; Gottfried, Gerald J.; Hahn, D. 2005. Occurrence, structure, and nitrogen-fixation of root nodules of actinorhizal Arizona alder. In: Gottfried, Gerald J.; Gebow, Brooke S.; Eskew, Lane G.; Edminster, Carleton B., comps. Connecting mountain islands and desert seas: biodiversity and management of the Madrean Archipelago II. Proc. RMRS-P-36. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 75-79
  • Keywords: Alnus oblongifolia, roots, nodules, nitrogen fixation, symbiosis, spore dispersal
  • Posted Date: June 8, 2006
  • Modified Date: June 17, 2016
  • Print Publications Are No Longer Available

    In an ongoing effort to be fiscally responsible, the Southern Research Station (SRS) will no longer produce and distribute hard copies of our publications. Many SRS publications are available at cost via the Government Printing Office (GPO). Electronic versions of publications may be downloaded, printed, and distributed.

    Publication Notes

    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
    • To view this article, download the latest version of Adobe Acrobat Reader.