Isozyme studies in provenance research of forest trees

Abstract

The nature and origin of the isozymes and the techniques for their detection in forest trees are briefly reviewed. The theories used to interpret the isozyme variation are summarized. Recent isozyme variation studies in provenance research are discussed in relation to known variation pattern detected by classical nursery and field tests. The populations of a tree species can be sometimes, but not always, distinguished by their isozyme patterns. For a number of species, relationships between environment of origin of the provenances and some isozyme frequencies have been statistically established. In one case (Picea sitchensis) where direct comparison between the variation pattern detected by isozymes and the genetic variation of silviculturally important traits was possible, no meaningful relationships between both patterns could be detected. Nei's genetic distances and indices of gene diversity do not appear to be useful in provenance research. The concept of genetic distance based on gene frequencies is probably not very useful in provenance research either.

Scandinavian colonial bentgrass diversity described by RAPD, variable chlorophyll fluorescence, and collecting site ecogeography

“…tritici resistance (Nevo et al, 1991), alfalfa (Medicago sativa L.) salinity tolerance (Smith et al, 1994), and birdsfoot trefoil (Lotus corniculatus L.) indeterminate flowering at high elevations (Steiner & Garcia de los Santos, 2001). Germplasm classifications based on molecular marker characteristics have been shown to be associated with ecogeographic features of accession collecting sites (Steiner, 1999), although there are examples where such relationships do not occur (Falkenhagen, 1985;Marshall, 1990). There are few examples that demonstrate how germplasm variability affecting plant physiological functions impacts its natural ecogeographic distribution (e.g., distribution of Trifolium repens L. glucoside and enzyme phenotypes spatially along geographic and altitude gradients) (Briggs & Walters, 1988).…”

Delineation of seed zones for European beech (Fagus sylvatica L.) in the Czech Republic based on isozyme gene markers

“…When experimental data on morphological or physiological traits are available from provenance, ecophysiological or other studies, these preliminary seed zones are mostly revised and new zones based on ecological as well as experimental data are defined [1,27]. At present, the Czech Republic is divided into 41 natural forest regions (figure 1) [11]. However, several studies have proven that there are clear geographical patterns in several tree species and/or loci [2,9], indicating adaptational mechanisms operating on these loci.…”

Assessment of natural and induced genetic variation in Alstroemeria using random amplified polymorphic DNA (RAPD) markers

“…As a consequence, different plant genotypes cannot always be distinguished (Santi & Lemoine, 1990;Tobolski & Kemery, 1992;Staub & Meglic, 1993). In addition, isozyme markers in some cases may be affected by environmental conditions and different stages of development (Kuhns & Fretz, 1978;Falkenhagen, 1985). These disadvantages can be overcome by DNA-based markers.…”