Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA, USA.
AoB Plants. 2014 Feb 4;6(0). doi: 10.1093/aobpla/plt055. Print 2014.
Genetic marker studies can assist restoration practice through selection of seed sources that conserve historical levels of gene diversity and population genetic differentiation. We examined genetic variation and structure within and among mainland and island populations of Elymus glaucus, a perennial bunchgrass species native to western North American grasslands that is targeted for grassland restoration. Island populations of E. glaucus represent sensitive sites and potentially distinctive seed sources for reintroduction, and little is known of their genetic composition. Genetic diversity and structure were estimated using amplified fragment length polymorphism markers for 21 populations and 416 individuals distributed across two coastal California mainland locations and three California Channel Islands. Eight primer combinations resulted in 166 markers, of which 165 (99.4 %) were polymorphic. The number of polymorphic bands was significantly greater among mainland populations relative to island sites, and locally common alleles were present for each sampled island and mainland location. Population structure was high (62.9 %), with most variation (55.8 %) distributed among populations, 7.1 % between mainland and island locations, and the remainder (37.1 %) within populations. Isolation by distance was only apparent among islands. Using marker data to recommend appropriate seed sources for restoration, E. glaucus seeds are best derived within islands with collections representing a large number of individuals from matching environments. Given the limited gene flow and prior evidence of adaptive divergence among populations of this species, regional collections are recommended in all cases to maintain diversity and to avoid long-distance introductions of highly differentiated plant material.
遗传标记研究可以通过选择保持历史基因多样性和种群遗传分化水平的种子来源来协助恢复实践。我们研究了北美西部草原多年生丛生草 Elymus glaucus 的大陆和岛屿种群内和种群间的遗传变异和结构，该物种是草原恢复的目标。E. glaucus 的岛屿种群代表了敏感地点和潜在独特的种子来源，用于再引入，但对其遗传组成知之甚少。使用扩增片段长度多态性标记对分布在加利福尼亚州两个沿海大陆地点和三个加利福尼亚海峡群岛的 21 个种群和 416 个个体进行了遗传多样性和结构估计。八个引物组合产生了 166 个标记，其中 165 个（99.4%）是多态的。与岛屿地点相比，大陆种群中的多态带数量明显更多，并且每个采样的岛屿和大陆地点都存在当地常见的等位基因。种群结构较高（62.9%），大部分变异（55.8%）分布在种群之间，7.1%分布在大陆和岛屿之间，其余（37.1%）分布在种群内。仅在岛屿之间存在距离隔离。使用标记数据为恢复推荐合适的种子来源，E. glaucus 的种子最好来自与匹配环境代表大量个体的岛屿。考虑到该物种种群之间有限的基因流和先前适应性分化的证据，在所有情况下都建议进行区域收集，以维持多样性并避免远距离引入高度分化的植物材料。
