Waud Michael, Wiegand Thorsten, Brys Rein, Lievens Bart, Jacquemyn Hans
Department of Biology, Plant Conservation and Population Biology, KU Leuven, B-3001, Leuven, Belgium.
Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM), Department of Microbial and Molecular Systems (M2S), KU Leuven, Campus De Nayer, B-2860, Sint-Katelijne-Waver, Belgium.
New Phytol. 2016 Jul;211(1):255-64. doi: 10.1111/nph.13894. Epub 2016 Feb 15.
In plant species that critically rely on mycorrhizal symbionts for germination and seedling establishment, distance-dependent decline of mycorrhizal fungi in the soil can be hypothesized to lead to significant spatial clustering as a result of nonrandom spatial patterns of seedling establishment. To test this hypothesis, we investigated the abundance and distribution of mycorrhizal fungi in the soil and how they relate to spatial patterns of adults and seedling recruitment in two related orchid species. We combined assessments of spatial variation in fungal abundance using quantitative PCR (qPCR) with spatial point pattern analyses based on long-term demographic data and cluster point process models. qPCR analyses showed that fungal abundance declined rapidly with distance from the adult host plants. Spatial point pattern analyses showed that successful recruitment in both species was clustered significantly around adult plants and that the decline in the neighborhood density of recruits around adults coincided with the decline of fungal abundance around adult plants. Overall, these results indicate that the distribution and abundance of fungal associates in the soil may have a strong impact on the aboveground distribution of its partner.
在严重依赖菌根共生体进行萌发和幼苗建立的植物物种中，可以推测，由于幼苗建立的非随机空间模式，土壤中菌根真菌的距离依赖性下降会导致显著的空间聚集。为了验证这一假设，我们研究了两种相关兰花物种土壤中菌根真菌的丰度和分布，以及它们与成株和幼苗补充空间模式的关系。我们将使用定量PCR（qPCR）评估真菌丰度的空间变化与基于长期种群统计学数据和聚类点过程模型的空间点模式分析相结合。qPCR分析表明，真菌丰度随着与成年寄主植物距离的增加而迅速下降。空间点模式分析表明，两个物种的成功补充都显著聚集在成年植株周围，并且成年植株周围新苗邻域密度的下降与成年植株周围真菌丰度的下降相一致。总体而言，这些结果表明，土壤中真菌共生体的分布和丰度可能对其共生伙伴的地上分布有强烈影响。
