Department of Biology, Portland State University, PO Box 751, Portland, OR 97207, USA.
Plant Commun. 2020 Jul 20;1(6):100100. doi: 10.1016/j.xplc.2020.100100. eCollection 2020 Nov 9.
Dispersal is one of the most important but least understood processes in plant ecology and evolutionary biology. Dispersal of seeds maintains and establishes populations, and pollen and seed dispersal are responsible for gene flow within and among populations. Traditional views of dispersal and gene flow assume models that are governed solely by geographic distance and do not account for variation in dispersal vector behavior in response to heterogenous landscapes. Landscape genetics integrates population genetics with Geographic Information Systems (GIS) to evaluate the effects of landscape features on gene flow patterns (effective dispersal). Surprisingly, relatively few landscape genetic studies have been conducted on plants. Plants present advantages because their populations are stationary, allowing more reliable estimates of the effects of landscape features on effective dispersal rates. On the other hand, plant dispersal is intrinsically complex because it depends on the habitat preferences of the plant and its pollen and seed dispersal vectors. We discuss strategies to assess the separate contributions of pollen and seed movement to effective dispersal and to delineate the effects of plant habitat quality from those of landscape features that affect vector behavior. Preliminary analyses of seed dispersal for three species indicate that isolation by landscape resistance is a better predictor of the rates and patterns of dispersal than geographic distance. Rates of effective dispersal are lower in areas of high plant habitat quality, which may be due to the effects of the shape of the dispersal kernel or to movement behaviors of biotic vectors. Landscape genetic studies in plants have the potential to provide novel insights into the process of gene flow among populations and to improve our understanding of the behavior of biotic and abiotic dispersal vectors in response to heterogeneous landscapes.
扩散是植物生态学和进化生物学中最重要但了解最少的过程之一。种子的扩散维持和建立种群，花粉和种子的扩散是种群内和种群间基因流动的原因。传统的扩散和基因流动观点假设仅由地理距离控制的模型，而不考虑对异质景观的扩散向量行为的变化。景观遗传学将种群遗传学与地理信息系统 (GIS) 相结合，以评估景观特征对基因流动模式（有效扩散）的影响。令人惊讶的是，相对较少的景观遗传学研究已经在植物上进行。植物具有优势，因为它们的种群是静止的，允许更可靠地估计景观特征对有效扩散率的影响。另一方面，植物的扩散本质上是复杂的，因为它取决于植物及其花粉和种子扩散媒介的栖息地偏好。我们讨论了评估花粉和种子运动对有效扩散的单独贡献的策略，并区分了影响植物栖息地质量的因素与影响影响向量行为的景观特征的影响。对三种物种的种子扩散的初步分析表明，景观阻力隔离是扩散率和模式的更好预测指标，而不是地理距离。在植物栖息地质量高的地区，有效扩散率较低，这可能是由于扩散核形状的影响或生物向量的运动行为的影响。植物中的景观遗传学研究有可能为种群间基因流动的过程提供新的见解，并提高我们对生物和非生物扩散媒介对异质景观的反应行为的理解。
