Plant Germplasm Research and Testing, United States Department of Agriculture, Agricultural Research Service Pullman, WA, USA.
Deschutes National Forest, United States Department of Agriculture Forest Service Bend, OR, USA.
Evol Appl. 2015 Feb;8(2):172-84. doi: 10.1111/eva.12240. Epub 2015 Jan 28.
Genetic variation for potentially adaptive traits of the key restoration species Sandberg bluegrass (Poa secunda J. Presl) was assessed over the intermountain western United States in relation to source population climate. Common gardens were established at two intermountain west sites with progeny from two maternal parents from each of 130 wild populations. Data were collected over 2 years at each site on fifteen plant traits associated with production, phenology, and morphology. Analyses of variance revealed strong population differences for all plant traits (P < 0.0001), indicating genetic variation. Both the canonical correlation and linear correlation established associations between source populations and climate variability. Populations from warmer, more arid climates had generally lower dry weight, earlier phenology, and smaller, narrower leaves than those from cooler, moister climates. The first three canonical variates were regressed with climate variables resulting in significant models (P < 0.0001) used to map 12 seed zones. Of the 700 981 km(2) mapped, four seed zones represented 92% of the area in typically semi-arid and arid regions. The association of genetic variation with source climates in the intermountain west suggested climate driven natural selection and evolution. We recommend seed transfer zones and population movement guidelines to enhance adaptation and diversity for large-scale restoration projects.
评估了美国山间西部关键恢复物种山蓝草（Poa secunda J. Presl）潜在适应性特征的遗传变异与源种群气候的关系。在两个山间西部地点建立了普通花园，每个地点都有来自 130 个野生种群的两个母本的后代。在每个地点收集了 2 年的数据，涉及与产量、物候和形态有关的 15 个植物特征。方差分析显示，所有植物特征都存在强烈的种群差异（P<0.0001），表明存在遗传变异。典范相关和线性相关都建立了源种群与气候变异性之间的关联。来自温暖、更干旱气候的种群的干重通常较低，物候较早，叶子较小较窄，而来自较凉爽、较湿润气候的种群则相反。前三个典范变量与气候变量进行了回归，得到了显著的模型（P<0.0001），用于绘制 12 个种子区。在绘制的 700981km²中，有四个种子区代表了典型半干旱和干旱地区 92%的面积。遗传变异与山间西部源气候的关联表明了气候驱动的自然选择和进化。我们建议采用种子转移区和种群迁移指南，以增强大规模恢复项目的适应能力和多样性。
