Plant Evolutionary Ecology, Institute of Evolution & Ecology, University of Tübingen, Tübingen, Germany.
Department of Community Ecology, Helmholtz Centre for Environmental Research-UFZ, Halle, Germany.
Plant Biol (Stuttg). 2019 May;21(3):551-558. doi: 10.1111/plb.12901. Epub 2018 Sep 22.
The growing number of restoration projects worldwide increases the demand for seed material of native species. To meet this demand, seeds are often produced through large-scale cultivation on specialised farms, using wild-collected seeds as the original sources. However, during cultivation, plants experience novel environmental conditions compared to those in natural populations, and there is a danger that the plants in cultivation are subject to unintended selection and lose their adaptation to natural habitats. Although the propagation methods are usually designed to maintain as much natural genetic diversity as possible, the effectiveness of these measures have never been tested. We obtained seed of five common grassland species from one of the largest native seed producers in Germany. For each species, the seeds were from multiple generations of seed production. We used AFLP markers and a common garden experiment to test for genetic and phenotypic changes during cultivation of these plants. The molecular markers detected significant evolutionary changes in three out of the five species and we found significant phenotypic changes in two species. The only species that showed substantial genetic and phenotypic changes was the short-lived and predominantly selfing Medicago lupulina, while in the other, mostly perennial and outcrossing species, the observed changes were mostly minor. Agricultural propagation of native seed material for restoration can cause evolutionary changes, at least in some species. We recommend caution, particularly in selfing and short-lived species, where evolution may be more rapid and effects may thus be more severe.
随着全球范围内修复项目的日益增多，对本土物种种子材料的需求也在不断增加。为了满足这一需求，种子通常通过在专门的农场进行大规模种植来生产，使用野生采集的种子作为原始来源。然而，在种植过程中，植物会经历与自然种群不同的新环境条件，而且种植的植物可能会受到意外选择的威胁，从而失去对自然栖息地的适应能力。尽管繁殖方法通常旨在尽可能保持自然遗传多样性，但这些措施的有效性从未经过测试。我们从德国最大的本土种子生产商之一获得了五种常见草原物种的种子。对于每一种植物，种子都来自于多个世代的种子生产。我们使用 AFLP 标记和一个共同的花园实验来测试这些植物在种植过程中的遗传和表型变化。分子标记检测到五种植物中有三种发生了显著的进化变化，我们发现有两种植物发生了显著的表型变化。唯一表现出大量遗传和表型变化的物种是短命的、主要是自交的 Lupinus lupulina，而在其他主要是多年生的、异交的物种中，观察到的变化大多是轻微的。为了进行修复而对本土种子材料进行农业繁殖可能会导致进化变化，至少在某些物种中是如此。我们建议谨慎行事，特别是在自交和短命的物种中，因为进化可能会更快，其影响可能会更严重。
