Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Genetic Differentiation and Heterozygosity in Pinyon Pine Associated with Resistance to Herbivory and Environmental Stress

Susan Mopper, Jeffry B. Mitton, Thomas G. Whitham, Neil S. Cobb and Kerry M. Christensen
Evolution
Vol. 45, No. 4 (Jun., 1991), pp. 989-999
DOI: 10.2307/2409704
Stable URL: http://www.jstor.org/stable/2409704
Page Count: 11
  • Read Online (Free)
  • Download ($4.00)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Genetic Differentiation and Heterozygosity in Pinyon Pine Associated with Resistance to Herbivory and Environmental Stress
Preview not available

Abstract

Arizona's Sunset Crater began erupting in 1064 AD and for the next 200 years buried over 2,000 km2 in ash, cinders, and lava. Soil analyses indicate that pinyon pines (Pinus edulis) currently colonizing the cinder fields are faced with a highly stressful environment. Many of these pinyons suffer chronic, intense insect herbivory that reduces plant growth and eliminates female cone production. In contrast, herbivory among pinyons growing in neighboring sandy-loam soils is minimal. Furthermore, numerous trees within the heavily infested cinder field population suffer relatively low herbivory and maintain normal growth and reproduction. We used four polymorphic enzymes to examine the relationship between herbivore attack, environmental stress and genotypes of the adjacent cinder field, and sandy-loam soil pinyon populations. Our results demonstrate that 1) resistant trees display significant genetic differences and are more heterozygous for two enzymes associated with herbivory than susceptible trees; and 2) the cinder-soil pinyons exhibit significant genetic differences and are more heterozygous for an enzyme associated with environmental stress than the neighboring sandy-loam soil pinyons. We conclude that heterozygosity of specific or closely linked loci may facilitate pinyon resistance to herbivory and environmental stress, and that strong selection across narrow geographic boundaries resulted in rapid genetic differentiation of pinyon populations.

Page Thumbnails

  • Thumbnail: Page 
989
    989
  • Thumbnail: Page 
990
    990
  • Thumbnail: Page 
991
    991
  • Thumbnail: Page 
992
    992
  • Thumbnail: Page 
993
    993
  • Thumbnail: Page 
994
    994
  • Thumbnail: Page 
995
    995
  • Thumbnail: Page 
996
    996
  • Thumbnail: Page 
997
    997
  • Thumbnail: Page 
998
    998
  • Thumbnail: Page 
999
    999