东北黑土区不同纬度农田土壤真菌分子生态网络比较

为了解东北黑土南部、中部和北部3个农田土壤真菌网络结构的异同以及物种之间的相互作用关系,本研究采用Illumina MiSeq技术对东北黑土农田3个长期肥料管理定位试验土壤真菌群落进行测序,并基于随机矩阵理论构建真菌分子生态网络.结果表明: 子囊菌、担子菌和接合菌为优势菌门,肉座菌目、腔菌目和粪壳菌目为优势菌目,但不同地区土壤中一些菌门和菌目的相对丰度存在显著差异.3个地区真菌分子生态网络结构显著不同,北部地区真菌网络更加复杂且物种之间存在更多竞争关系,南部地区真菌网络更不稳定,易受外界环境扰动.3个真菌网络仅有7个共有节点,且共有节点在各地区的连通度存在很大差异.通过亚网络的构建发现,从南到北肉座菌目网络趋于复杂,腔菌网络恰好相反.南部、中部和北部地区真菌网络的关键物种分别为毛壳菌、腔菌和青霉菌.土壤pH值和土壤全氮含量是同时影响3个真菌网络的主要土壤理化因子.

Comparison on fungal molecular ecological networks of agricultural soils with different latitudes in the black soil region of Northeast China

To investigate the differences of fungal network structures and interaction among fungal species of in black soil region of Northeast China, Illumina MiSeq sequencing was used to reveal the fungal communities in the three long-term fertilization experimental fields. Fungal molecular ecological networks were constructed based on random matrix theory (RMT). The results demonstrated that Ascomycota, Basidiomycota and Zygomycota were the dominant phyla and Hypocreales, Pleosporales and Sordariales were the dominant order, but the relative abundance of some dominant taxa significantly varied in different locations. Fungal molecular ecological network structures in three locations showed significant difference, with more complex fungal network being observed in north location with more competitive relations among species. The fungal network in south location was more easily disturbed by environmental perturbations with less stability. Only seven shared nodes were detected among three fungal molecular ecological networks. There were large differences in connectivity of shared nodes within individual fungal network. The subnetwork of Hypocreales was gradual complex from south to north location while subnetwork of Pleosporales presented reversed trend. The key species of south, middle and north locations were Chaetomiaceae, Pleosporales and Penicillium coralligerum, respectively. Soil pH and total N content were the main soil properties simultaneously influencing three fungal networks.