© 1994 Heron Publishing—Victoria, Canada
The choice of genetic material for mechanistic studies of adaptation in forest trees
R. F. Stettler (1) and H. D. Bradshaw, Jr. (2)
1. College of Forest Resources, University of Washington, Seattle, WA 98195, USA / 2. Department of Biochemistry, University of Washington, Seattle, WA 98195, USA / Received September 24, 1993
Summary
There is considerable urgency to study the mechanisms by which forest trees track environmental change, given the prospect
of possible rapid climatic changes. Environmental tracking is achieved through three basic processes: (1) expression of phenotypic
plasticity at the level of the individual; and (2) evolutionary change and (3) migration, both expressed at the level of the
population over generations. The current distribution and genetic architecture of a species reflect how these processes interacted
in response to past climatic changes during and after the last glaciation. Part of that record is encoded in the DNA of the
current generation of trees and, as a result of existing field tests, is accessible for study. These field tests include,
in ascending order of genetic resolution, (1) provenance tests, (2) progeny tests, and (3) three-generation clonal tests;
as well as (4) clone tests, with or without genetic structure. The suitability and limitations of these tests for mechanistic
studies of environmental tracking are described, both as field installations and as sources of material for parallel in-depth
studies. We conclude that they represent an important information resource, which deserves to be more effectively used by
the scientific community.
Keywords:
climatic change, clonal tests, environmental tracking, evolutionary change, migration, phenotypic plasticity, progeny tests,
provenance tests.
