<b>Spatial structure of soil-borne fungal plant pathogens: a brief review of the evidence and a way forward using </b><b><i>Macrophomina phaseolina</i></b><b> as an example</b>

Understanding the link between spatial structure of soil-borne fungal plant pathogens (SFPP) and ecological conditions is an important first step to understanding how these organisms impact agricultural and untilled systems. A literature review revealed that most SPFF spatial patterns studies have occurred in tilled systems and relied on rudimentary statistical approaches. Here we begin to address this knowledge gap by quantifying the spatial pattern of <i>M. phaseolina</i> at multiple spatial scales in an untilled grassland system in Northeastern Kansas, U.S.A, and relate these patterns to soil and plant variables. Using microsclerotia density as a measure of <i>M. phaseolina</i> abundance, we found high spatial variability in untilled soil, even at very fine scales (7 cm). Using point pattern analysis, we found no evidence of spatial aggregation. Rather, <i>M. phaseolina</i> density was randomly distributed and did not strongly associate with any measured soil or plant variables. Our findings contrast with previous work detecting aggregation of <i>M. phaseolina</i> and other SFPP likely due to our use of more informative spatial statistics that examine multiple scales and the ecological dichotomy of untilled grassland systems and row-crop agricultural systems. Additionally, the fact that high spatial variation of <i>M. phaseolina</i> over small scales was poorly explained by plant or soil variables suggests that a better understanding of temporal variation may be necessary to identify the factors that control SFPP abundance.

理解土传真菌植物病原菌（soil-borne fungal plant pathogens, SFPP）的空间结构与生态条件之间的关联，是解析这类生物如何影响农业与免耕系统的重要前置步骤。文献调研显示，现有关于土传真菌植物病原菌空间分布格局的研究大多聚焦于耕作农田系统，且采用的统计方法较为基础。本研究通过量化美国堪萨斯州东北部一处免耕草地生态系统中菜豆壳球孢菌（<i>M. phaseolina</i>）在多空间尺度下的分布格局，并将其与土壤及植物变量进行关联分析，以期填补这一研究空白。本研究以微菌核密度作为菜豆壳球孢菌丰度的衡量指标，结果显示免耕土壤中该菌的空间变异程度极高，即便在7厘米的极细尺度下亦是如此。通过点格局分析，本研究未发现该菌存在空间聚集性的证据。相反，菜豆壳球孢菌的密度呈随机分布状态，且与所有测得的土壤及植物变量均无显著关联。本研究结果与此前检测到菜豆壳球孢菌及其他土传真菌植物病原菌存在聚集性的研究有所不同，这一差异可能源于两方面：其一，本研究采用了可解析多尺度信息的更完善的空间统计方法；其二，免耕草地系统与条播农业系统本身存在生态特性上的分异。此外，菜豆壳球孢菌在小尺度下的高空间变异无法通过植物或土壤变量得到充分解释，这一结果表明，若要明确调控土传真菌植物病原菌丰度的关键因素，或许需要对其时间动态变化开展更深入的研究。

搜集汇总

背景与挑战

背景概述

该数据集是一篇期刊文章，聚焦于在未耕作草地系统中研究土壤传播真菌植物病原体Macrophomina phaseolina的空间结构，使用点模式分析等新工具揭示其在多个空间尺度上的随机分布特征，与土壤和植物变量关联较弱。研究强调了未耕作系统与农业系统的生态差异，并指出时空变异对理解病原体丰度的重要性。