Genetic structure and variability in jack pine populations: effects of insularity

Author:

Gauthier Sylvie,Simon Jean-Pierre,Bergeron Yves

Abstract

To determine the effects of insularity on the genetic structure and variability of jack pine (Pinusbanksiana Lamb.) populations at a regional scale, stands from two different landscapes were studied: two islands in a lake and two mainland areas. The two landscapes have been affected by different fire regimes. The genetic structure and variability of the four populations were analyzed using cellulose acetate gel electrophoresis of 11 enzyme systems. The analysis of 22 loci showed an average polymorphism of 60.0%, a mean of 2.3 alleles per locus, a mean of 1.185 effective alleles per locus, and an observed level of heterozygosity of 0.171. The Fis values (i.e., fixation index of individuals relative to their population) for all but two loci indicated an excess of heterozygotes compared with the expected numbers under Hardy–Weinberg equilibrium. The genetic differentiation among populations was weak (Fst = 0.018). There were no significant differences among the four populations for five genetic parameters (mean number of alleles per locus, mean number of effective alleles per locus, percentage of polymorphic loci, and observed or expected heterozygosity). Although the allelic frequencies were homogeneous between island populations, a significant heterogeneity in allele frequencies was observed between mainland populations. The results suggest that gene flow in island populations is sufficiently high to maintain a level of genetic variability similar to that found in mainland populations and to counteract the effect of isolation and differential selective pressures resulting from different disturbance regimes.

Publisher

Canadian Science Publishing

Subject

Ecology,Forestry,Global and Planetary Change

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3