Department of Biological Sciences, University of Alberta Edmonton, Canada.
Evol Appl. 2012 Dec;5(8):879-91. doi: 10.1111/j.1752-4571.2012.00266.x. Epub 2012 May 8.
Understanding the physical and genetic structure of hybrid zones can illuminate factors affecting their formation and stability. In north-central Alberta, lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia) and jack pine (Pinus banksiana Lamb) form a complex and poorly defined hybrid zone. Better knowledge of this zone is relevant, given the recent host expansion of mountain pine beetle into jack pine. We characterized the zone by genotyping 1998 lodgepole, jack pine, and hybrids from British Columbia, Alberta, Saskatchewan, Ontario, and Minnesota at 11 microsatellites. Using Bayesian algorithms, we calculated genetic ancestry and used this to model the relationship between species occurrence and environment. In addition, we analyzed the ancestry of hybrids to calculate the genetic contribution of lodgepole and jack pine. Finally, we measured the amount of gene flow between the pure species. We found the distribution of the pine classes is explained by environmental variables, and these distributions differ from classic distribution maps. Hybrid ancestry was biased toward lodgepole pine; however, gene flow between the two species was equal. The results of this study suggest that the hybrid zone is complex and influenced by environmental constraints. As a result of this analysis, range limits should be redefined.
理解杂种区的物理和遗传结构可以阐明影响其形成和稳定性的因素。在艾伯塔省中北部，落矶山松（Pinus contorta Dougl. ex Loud. var. latifolia）和短叶松（Pinus banksiana Lamb）形成了一个复杂且定义不明确的杂种区。鉴于近年来山松甲虫已扩展到短叶松中，因此更好地了解这个区域是相关的。我们通过对来自不列颠哥伦比亚省、艾伯塔省、萨斯喀彻温省、安大略省和明尼苏达州的 1998 年落矶山松、短叶松和杂种进行 11 个微卫星基因分型，对该区域进行了特征描述。我们使用贝叶斯算法计算了遗传祖先，并利用该算法对物种出现与环境之间的关系进行建模。此外，我们分析了杂种的祖先，以计算落矶山松和短叶松的遗传贡献。最后，我们测量了纯物种之间的基因流。我们发现，松类的分布是由环境变量解释的，这些分布与经典分布图不同。松类的分布是由环境变量解释的，这些分布与经典分布图不同。杂种的祖先偏向于落矶山松，但两种物种之间的基因流是相等的。这项研究的结果表明，杂种区是复杂的，受到环境限制的影响。因此，应该重新定义范围界限。
