Schiro Gabriele, Colangeli Pierluigi, Müller Marina E H
Leibniz Centre for Agricultural Landscape Research, Research Area 1 "Landscape Functioning", Müncheberg, Germany.
University of Potsdam, Ecology and Ecosystem Modelling, Potsdam, Germany.
Front Microbiol. 2019 Sep 10;10:2095. doi: 10.3389/fmicb.2019.02095. eCollection 2019.
Plant associated microbial communities have recently received a lot of attention because thought to play a fundamental role in plant health and development. Focusing on cultivated crops, optimized farming practices must consider the role of these communities when aiming at reducing the impact of pathogens and increasing yields. Typical inhabitants of plant's phyllosphere are bacteria and microscopic fungi, some of them pathogenic for the plant and dangerous for the consumers, due to the production of toxins. In order to efficiently manage the microbiome, the natural drivers regulating community assembly must be clearly understood. In our study we investigated the within field variation of the phyllosphere mycobiome of wheat ears by metabarcoding of the fungal internal transcribed sequence 1 (ITS1). We selected a field characterized by a high topographic heterogeneity, which is reflected in differences in plant productivity and fitness across it. Samples were taken from 30 sampling points laid across the field where data-loggers were placed, measuring the productivity driven under canopy microclimate. The microclimatic conditions were tested as a source of potential environmental variance. Further independent spatial structures were tested using spatial eigenvector maps (MEMs). Results show considerable differences in the phyllosphere composition across the field. The local under canopy environmental conditions at each point were strong predictors of the community composition. Independent spatial effects given by the geographical position of the sampling points showed also a weaker but significant effect. Moreover we observed different spatial responses from different fungal phyla, with results resembling those described in studies done at a regional scale. This study is the first one to investigate the spatial variation of the phyllosphere mycobiome of a commercial crop within the same field. It contributes to the study of the epidemiology and community assembly dynamics of wheat phyllosphere fungi, showing how in-field community variations are the results of different environmental and spatial processes acting simultaneously. It also shows how heterogeneous fields are a smart and useful system to investigate the ecological mechanisms regulating plant microbiome composition.
与植物相关的微生物群落最近受到了广泛关注，因为人们认为它们在植物健康和发育中起着至关重要的作用。以栽培作物为重点，优化的耕作方式在旨在减少病原体影响并提高产量时，必须考虑这些群落的作用。植物叶际的典型居民是细菌和微观真菌，其中一些对植物具有致病性，并且由于产生毒素而对消费者构成危险。为了有效地管理微生物组，必须清楚地了解调节群落组装的自然驱动因素。在我们的研究中，我们通过对真菌内部转录间隔区1（ITS1）进行元条形码分析，研究了麦穗叶际真菌群落的田间变异。我们选择了一个地形高度异质性的田地，这反映在整个田地上植物生产力和适应性的差异上。样本取自遍布田地的30个采样点，在这些点放置了数据记录器，测量了冠层微气候下的生产力驱动因素。微气候条件被测试为潜在环境变异的来源。使用空间特征向量图（MEMs）测试了进一步的独立空间结构。结果表明，整个田地的叶际组成存在相当大的差异。每个点的局部冠层环境条件是群落组成的有力预测指标。采样点地理位置给出的独立空间效应也显示出较弱但显著的影响。此外，我们观察到不同真菌门的不同空间响应，结果与在区域尺度上进行的研究中描述的结果相似。这项研究是首次在同一田地里调查商业作物叶际真菌群落的空间变异。它有助于研究小麦叶际真菌的流行病学和群落组装动态，表明田间群落变异是不同环境和空间过程同时作用的结果。它还表明，异质田地是研究调节植物微生物组组成的生态机制的一个智能且有用的系统。
