【摘要】 为揭示重金属镉（Cd）污染对农田土壤丛枝菌根（arbuscular mycorrhiza,AM）真菌群落组成及多样性的影响机制，以Cd污染区和未污染区农田土壤为研究对象，利用高通量测序方法，分析土壤AM真菌群落组成及多样性间的差异，研究农田土壤Cd污染下驱动AM真菌群落组成及多样性变化的主要土壤环境因子及其效应。结果表明：Cd污染与未污染区农田土壤中AM真菌优势属均为球囊霉属（Glomus）和类球囊霉属（Paraglomus），所占比例为37.80%～57.27%；球囊霉属AM真菌的相对丰度存在极显著差异（P<0.01）。Cd污染区域土壤中AM真菌群落物种数、Chao1指数比未污染区土壤分别低21.97%、22.36%,Shannon指数、Simpson指数分别低14.80%、5.26%，且差异极显著（P<0.01）。非度量多维尺度（NMDs）分析表明，Cd污染区土壤AM真菌群落组成与未受污染区土壤间存在差异，Cd污染显著改变了土壤AM真菌群落的β多样性。Cd污染下，土壤有效态Cd(P=0.004)和全磷质量比（P=0.042）是驱动AM真菌群落结构发生变化的主要因子。土壤全Cd质量比（P=0.01）是引起AM真菌群落多样性变化的主要因素。土壤有效态Cd质量比对AM真菌群落组成、土壤总Cd质量比对AM真菌多样性变化有直接效应；污染区土壤中Cd质量比较土壤全磷质量比更容易引起土壤AM真菌群落结构及多样性的变化。更多还原

【Abstract】 In order to reveal the impact mechanism of heavy metal cadmium(Cd) pollution on the composition and diversity of arbuscular mycorrhizal(AM) fungal communities in farmland, soils samples from Cd-contaminated area and uncontaminated area of farmland were collected as the research objects. The differences in the composition and diversity of soil AM fungal communities were analyzed by high-throughput sequencing. The main soil environmental factors driving the changes in the composition and diversity of AM fungal communities under soil Cd contamination, as well as their effects were studied. The results showed that the dominant genera of AM fungi in both Cd-contaminated and non-contaminated agricultural soils were Glomus and Paraglomus, accounting for 37.80%～57.27% of the community. There was a highly significant difference in the relative abundance of Glomus AM fungi between the two treatments(P<0.01). The species number of AM fungi and the Chao1 index in the soil of the Cdcontaminated areas were 21.97% and 22.36% lower, respectively, compared to the non-contaminated areas. The Shannon index and Simpson index were 14.80% and 5.26% lower, respectively, with highly significant differences between treatments(P<0.01).Non-metric multidimensional scaling(NMDs) analysis showed that there were differences in the composition of AM fungal communities between soils from Cd-contaminated and non-contaminated areas, and Cd contamination significantly changed the β-diversity of the soil AM fungal community. Under Cd contamination, available Cd(P=0.004) and total phosphorus concentration(P=0.042) in the soil were the main factors driving changes in the composition of the AM fungal community. The total soil Cd concentration(P=0.01) was the main factor causing changes in AM fungal community diversity. The content of available Cd in the soil had a direct effect on the composition of the AM fungal community, and the total soil Cd content had a direct effect on changes in AM fungal diversity. The content of Cd in the soil of the contaminated area was more likely to cause changes in the composition and diversity of the soil AM fungal community compared to the total phosphorus content.更多还原