Table_1_Biogeography and Ecology of Magnaporthales: A Case Study.DOCX

The order Magnaporthales belongs to Sordariomycetes, Ascomycota. Magnaporthales includes five families, namely Ceratosphaeriaceae, Pseudohalonectriaceae, Ophioceraceae, Pyriculariaceae, and Magnaporthaceae. Most Magnaporthales members are found in Poaceae plants and other monocotyledonous herbaceous plants ubiquitously as plant pathogens or endophytic fungi, and some members are found in decaying wood or dead grass as saprophytic fungi. Therefore, studying the biogeography and ecology of Magnaporthales is of great significance. Here, we described the biodiversity of endophytic Magnaporthales fungi from Poaceae at three latitudes in China and conducted a meta-analysis of the geography and ecology of Magnaporthales worldwide. We found that Magnaporthales is a dominant order in the endophytic fungi of Poaceae. More than half of the endophytic Magnaporthales fungi have a taxonomically uncertain placement. Notably, few endophytic fungi are grouped in the clusters with known saprophytic or pathogenic Magnaporthales fungi, indicating that they may have saprophytic and parasitic differentiation in nutritional modes and lifestyles. The meta-analysis revealed that most species of Magnaporthales have characteristic geographical, host, and tissue specificity. The geographical distribution of the three most studied genera, namely Gaeumannomyces, Magnaporthiopsis, and Pyricularia, in Magnaporthales may depend on the distribution of their hosts. Therefore, studies on the endophytic fungal Magnaporthales from monocotyledonous plants, including Poaceae, in middle and low latitudes will deepen our understanding of the biogeography and ecology of Magnaporthales.

稻瘟菌目（Magnaporthales）隶属于子囊菌门（Ascomycota）的子囊菌纲（Sordariomycetes）。该目下共包含5个科，分别为角孢壳科（Ceratosphaeriaceae）、假旋孢腔菌科（Pseudohalonectriaceae）、蛇形菌科（Ophioceraceae）、梨孢科（Pyriculariaceae）以及稻瘟菌科（Magnaporthaceae）。稻瘟菌目多数类群作为植物病原菌或内生真菌（endophytic fungi），广泛定殖于禾本科（Poaceae）及其他单子叶草本植物中；部分类群则以腐生真菌（saprophytic fungi）的形式生存于腐木或枯草丛中。因此，开展稻瘟菌目的生物地理学与生态学研究具有重要价值。
本研究对中国境内3个纬度梯度下禾本科植物体内的内生稻瘟菌目真菌多样性进行了系统描述，并对全球范围内稻瘟菌目的地理分布与生态特征开展了元分析（meta-analysis）。研究发现，稻瘟菌目是禾本科植物内生真菌中的优势类群；超过半数的内生稻瘟菌目真菌分类学位置尚未明确。值得注意的是，仅有极少数内生真菌与已知的腐生或致病型稻瘟菌目真菌聚为同一演化簇，这提示其在营养模式与生活方式上可能存在腐生-寄生分化。
元分析结果表明，多数稻瘟菌目物种具有显著的地理、宿主及组织特异性。该目中研究较为深入的3个属——顶囊壳属（Gaeumannomyces）、稻瘟菌属（Magnaporthiopsis）和梨孢属（Pyricularia）——的地理分布可能与其宿主植物的分布紧密相关。因此，针对中低纬度区域包括禾本科在内的单子叶植物内生稻瘟菌目真菌的研究，将有助于深化我们对稻瘟菌目生物地理学与生态学的认知。