Download genetic variation

Forest genetic variation is a evolutionary result of adaption of environmental heterogeneity
(Jelinski, 1997), and can be maintained through arboreal reproduction if the diversity was
acquired through recombination, introgression, or somatic mutation (Rasmussen and Kollmann,
2007). The variation is regulated by differential selection pressures such as climate, soil,
disturbance, geographical position, gene flow, population size, and founder effects (Lesica and
Allendorf, 1995; Ohsawa et al., 2008). Studying of genetic variation can help us to identify the
species, assess the distribution, examine the genetic structure, or probe the phenotype. Moreover,
it was applied to select the high-quality timber resources for forest industry.
Genetic variation can be detected by several methods: provenance trial, molecular genetic
marker, and quantitative traits locus (QTL) mapping, integrating approach (Gonzalez-Martinez et
al., 2006).
The directly method to test the genetic variation is using molecular markers, but the adaptive
traits are not correlation to the results, which depend on the testing level (Hall et al., 2007).
Genetic variation among tree populations is routinely studied with provenance trials (e.g.
Hamann et al., 2000; Kleinschmit et al., 2004; Savva et al., 2007)The essence of the provenance
trials is to compare growth and adaptive traits of different genotypes within or across species.
Normally, in order to study population differences within species, the provenance trials take
plants of this species from different sites and plant them in a common garden environment,
where they can be exposed to identical environmental conditions—soils, climate, water and
photoperiod—with a systematic experimental design that accounts for random site variation
(Bower and Aitken, 2008). Because different genotypes may respond to the same environment
conditions differently in phenology and growth traits, the observed differences can reflect withinspecies genetic variations. This information can be used to create guidelines of seed transfers and
to delineate seed zones. Seed zones are those ….
Deciduous
The objective of limiting seed movement in reforestation is to ensure that planting stock is not
mal-adapted to environmental conditions of the planting site. For example, northern provenances
of Norway spruce (Picea abies), have earlier budburst and should therefore not be used in
southern planting environments to avoid late spring frost damage (Leinonen and Hanninen,
2002).
Bower A.D., Aitken S.N. (2008) Ecological genetics and seed transfer guidelines for Pinus
albicaulis (Pinaceae). American Journal of Botany 95:66-76.
Gonzalez-Martinez S.C., Krutovsky K.V., Neale D.B. (2006) Forest-tree population genomics
and adaptive evolution. New Phytologist 170:227-238. DOI: DOI 10.1111/j.14698137.2006.01686.x.
Hall D., Luquez V., Garcia V.M., St Onge K.R., Jansson S., Ingvarsson P.K. (2007) Adaptive
population differentiation in phenology across a latitudinal gradient in European Aspen
(Populus tremula, L.): A comparison of neutral markers, candidate genes and phenotypic
traits. Evolution 61:2849-2860. DOI: DOI 10.1111/j.1558-5646.2007.00230.x.
Hamann A., Koshy M.P., Namkoong G., Ying C.C. (2000) Genotype x environment interactions
in Alnus rubra: developing seed zones and seed-transfer guidelines with spatial statistics
and GIS. Forest Ecology and Management 136:107-119.
Jelinski D.E. (1997) On genes and geography: a landscape perspective on genetic variation in
natural plant populations. Landscape and Urban Planning 39:11-23.
Kleinschmit J.R.G., Kownatzki D., Gegorius H.R. (2004) Adaptational characteristics of
autochthonous populations - consequences for provenance delineation. Forest Ecology
and Management 197:213-224.
Leinonen I., Hanninen H. (2002) Adaptation of the timing of bud burst of Norway spruce to
temperate and boreal climates. Silva Fennica 36:695-701.
Lesica P., Allendorf F.W. (1995) When Are Peripheral-Populations Valuable for Conservation.
Conservation Biology 9:753-760.
Ohsawa T., Saito Y., Sawada H., Ide Y. (2008) Impact of altitude and topography on the genetic
diversity of Quercus serrata populations in the Chichibu Mountains, central Japan. Flora
203:187-196. DOI: DOI 10.1016/j.flora.2007.02.007.
Rasmussen K.K., Kollmann J. (2007) Genetic diversity, spatial patterns, and growth of root
sprouts in a temperate tree at the northern distribution limit. Ecoscience 14:250-258.
Savva Y., Denneler B., Koubaa A., Tremblay F., Bergeron Y., Tjoelker M.G. (2007) Seed transfer
and climate change effects on radial growth of jack pine populations in a common garden
in Petawawa, Ontario, Canada. Forest Ecology and Management 242:636-647.