Abstract Detail

Population Genetics

XU, Huaitong [1], Tremblay, Francine [2], Bergeron, Yves [3].

Landscape features influence genetic diversity in "tree of life", eastern white cedar (Thuja occidentalis).

Eastern white cedar (Thuja occidentalis L.), "tree of life", is a wind-pollinated conifer with a broad distribution native to North America. It is also one of the key tree species in the Canadian boreal forest. It is listed as endangered species in Indiana, Massachusetts, New Jersey, and as threatened species in Connecticut, Illinois, Kentucky, and Maryland. In this study, we examined the genetic diversity and genetic structure in eastern white cedar (EWC) in a lacustrine landscape in the boreal zone in Canada using molecular markers. We selected three different EWC forest types, including; 1) island, 2) fragmented forest patches, which escaped from forest fires, and 3) mainland continuous forests, which were used as control. Our results showed that there was a significant difference in genetic diversity among these three groups for allelic richness (AR) (P=0.020) with mainland having the highest allelic richness (5.59) and fragmented patches the lowest (5.06). Population differentiation was generally low but fragmented patches had higher genetic differentiation (Fst=0.052), than that of two other ones (island, Fst=0.015; mainland, Fst=0.023). High level of gene flow was detected. Mainland forests served as the source for island stands and fragmented forest patches. Private alleles were detected in all sites with mainland bearing the highest (forest patches, 5 private alleles; islands, 8; mainland, 15). Our results suggest that both climate (wind) and fire play an important role in the genetic structure of eastern white cedar. The island populations are not genetically isolated mainly due to high gene flow across open space.

Broader Impacts:

1 - Université du Québec en Abitibi-Témiscamingue, Institut de recherche sur les forêts, 445 boul. de l'Université , Rouyn-Noranda , QC, J9X 5E4 , Canada
2 - Université du Québec en Abitibi-Témiscamingue, Institut de recherche sur les forêts, 445 boul. de l'Université,, Rouyn-Noranda, QC, J9X 5E4 , Canada
3 - UQAT, Chaire AFD, 445 Boul. De L'Université, Rouyn-Noranda, QC, J9X 5E4, Canada

Keywords:
Eastern white cedar
Boreal forest
microsatellite
population genetics
Lacustrine landscape
Thuja occidentalis L.
Tree of life.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Battelle South/Convention Center
Date: Monday, July 9th, 2012
Time: 5:30 PM
Number: PPG002
Abstract ID:444