Departamento de Biología Vegetal, Universidad Politécnica de Madrid, Ciudad Universitaria, E-28040, Madrid, Spain.
Am J Bot. 2003 Dec;90(12):1688-95. doi: 10.3732/ajb.90.12.1688.
Random amplified polymorphic DNA (RAPD) markers were used to study the spatial genetic structure in two populations (Bolarque and Entrepeñas) of endangered cliff specialist Antirrhinum microphyllum Rothm. (Scrophulariaceae). Mantel tests found no significant linear correlations between geographic and genetic data. However, redundancy analysis (RDA) models developed using the spatial data as the constraining matrix were highly significant, and spatial data explained 13.6% and 11.1% of total genetic variation in Bolarque and Entrepeñas, respectively. Moran's I correlograms and Mantel correlograms revealed a positive autocorrelation in the first distance class (15 m), which suggests a patchy distribution of genetic diversity. This distribution is consistent with the genetic vicinities that are expected from the territorial behavior of main pollinator Rhodanthidium sticticum (Megachilidae), the predominant short-distance seed dispersal, and the patchy spatial distribution of available safe sites. The gradient pattern obtained in Entrepeñas was consistent with standard isolation-by-distance models. However, a differential sinusoidal pattern was obtained in Bolarque, which would indicate a more frequent gene flow between patches and might be due to lower plant density there. The spatial genetic structure coexists with a strict self-incompatibility system in the species. Simplified RDA models obtained using a stepwise forward selection comprised the easting component in Entrepeñas and the easting and northing components in Bolarque. Similar results were obtained with directional correlograms. These differential patterns can be explained by the distinct spatial arrangement of the populations (linear and bidimensional in Entrepeñas and Bolarque, respectively).
随机扩增多态性 DNA（RAPD）标记被用于研究濒危的悬崖专家 Antirrhinum microphyllum Rothm.（玄参科）的两个种群（Bolarque 和 Entrepeñas）的空间遗传结构。Mantel 检验发现地理和遗传数据之间没有显著的线性相关。然而，使用空间数据作为约束矩阵开发的冗余分析（RDA）模型具有高度显著性，并且空间数据分别解释了 Bolarque 和 Entrepeñas 总遗传变异的 13.6%和 11.1%。Moran's I 相关图和 Mantel 相关图显示在第一距离类（15 m）中存在正自相关，这表明遗传多样性呈斑块状分布。这种分布与主要传粉者 Rhodanthidium sticticum（Megachilidae）的领地行为所预期的遗传近缘性、短距离种子传播的主要方式以及可用安全地点的斑块状空间分布一致。在 Entrepeñas 获得的梯度模式与标准的隔离距离模型一致。然而，在 Bolarque 中获得了差异正弦模式，这表明斑块之间的基因流动更为频繁，这可能是由于那里的植物密度较低所致。该物种的空间遗传结构与严格的自交不亲和系统并存。使用逐步向前选择获得的简化 RDA 模型包括 Entrepeñas 的东经分量和 Bolarque 的东经和北纬分量。定向相关图也得到了类似的结果。这些差异模式可以通过种群的不同空间排列（Entrepeñas 中的线性和二维排列和 Bolarque 中的二维排列）来解释。
