ABSTRACT

Suillus luteus is a common ectomycorrhizal (EM) fungus associated with several Pinus species. It is distributed throughout the Northern Hemisphere and has been introduced into South America and New Zealand. We examined the genetic structure and population biology of S. luteus, which was introduced into Patagonian plantations with Pinus species in Argentina. Overall, 106 samples were collected at 11 geographically separated sites (i.e., Pinus plantations) along a latitudinal gradient in Patagonia (ca. 38°–46° south latitude). Phylogenetic analyses confirmed placement in S. luteus. Genetic analysis demonstrated moderate within-site genetic diversity, but low differentiation between sites. No clear clusters were detected geographically or in relation to host species of Pinus. Our results suggest that the weak genetic structure of the species reflects the short time that has elapsed since the introduction of S. luteus into Patagonia, and its expansion with exotic afforestation there. Moreover, the lack of structure is consistent with a founder effect, suggesting the introduction of a small number of genets that spread throughout all the plantations. Therefore, the high level of gene flow and weak genetic structure observed are probably related to the anthropogenic movement of inoculum associated with forestry practices.

摘要

Suillus luteus是一种常见的外生菌根 (EM) 真菌，与几种松属物种有关。它分布于整个北半球，并已引入南美洲和新西兰。我们检查了S. luteus的遗传结构和种群生物学，它被引入阿根廷的松树种在巴塔哥尼亚人工林中。总体而言，在巴塔哥尼亚（南纬约 38°–46°）的纬度梯度上，在 11 个地理上分离的地点（即松树种植园）收集了 106 个样本。系统发育分析证实了在S. luteus 中的位置. 遗传分析表明，位点内遗传多样性中等，但位点之间的分化程度较低。在地理上或与松属寄主物种相关的情况下，没有发现明显的集群。我们的研究结果表明，该物种的弱遗传结构反映了自S. luteus引入巴塔哥尼亚以来所经历的短暂时间，以及随着那里外来植树造林的扩张。此外，缺乏结构与奠基者效应一致，这表明引入了少量分布在所有种植园中的基因。因此，观察到的高水平基因流和弱遗传结构可能与与林业实践相关的接种物的人为运动有关。