关键词: 毛竹, 伴矿景天, 植物修复, 重金属, 污染土壤, 微生物群落

Abstract: [Objective] This study aimed to investigate the phytoremediation effect of Phyllostachys edulis (moso bamboo) with a hyperaccumulator Sedum plumbizincicola in heavy metal contaminated soil and to explore the influence of different planting patterns on soil microbial communities. The result could provide scientific support for the remediation of heavy metal contaminated soil.[Method] Single cropping of moso bamboo (SM), intercropping of moso bamboo×S. plumbizincicola (IMS) and the control (uncultivated) (CK) were established in the soil with long-term heavy metal (Cu, Zn and Cd) pollution.The changes of soil chemical properties and heavy metal contents were determined. And soil microbial community structure was analyzed by Illumina MiSeq high throughput sequencing technique.[Result] In four years after establishing the systems, the available and total heavy metals contents in the soil were both in the following order:CK > SM > IMS. The contents of total Cu, Zn and Cd in IMS were 47.8%, 21.6%, 23.7% lower than those in CK, and in SM were 39.0%, 12.5%, 23.0% lower than those in CK, respectively. The contents of available Cu, Zn and Cd in IMS were 65.0%, 28.7%, 48.4% lower than those in CK, and in MM were 52.8%, 24.8%, 45.5% lower than those in CK, respectively. There were ten phyla of microorganisms with the abundance >1% in the three type soils, including Proteobacteria, Acidobacteria, Gemmatimonadetes, Planctomycetes, Verrucomicrobia, Actinobacteria, Bacteroidetes, Nitrospira, Chloroflexi and WS3. Proteobacteria was the most dominant bacteria, accounting for more than 30% in each sample. There was a significant difference (P<0.05) in the relative abundance of Acidobacteria, Nitrospira, Bacteroidetes and Chloroflexi among the two planting patterns (SM and IMS) and the control soil.The analysis of the correlation among microorganisms and soil heavy metals showed that the total and the available values of heavy metals were significantly negatively correlated with Nitrospira and Acidobacteria (except for available Zn) (P<0.01), and significantly positively correlated with Bacteroidetes (P<0.01). Although there were no significant differences in α-diversity analysis, there were significant differences of microorganisms among three types of soils (ANOSIM, P<0.05) according to the β-diversity analysis.[Conclusion] The IMS and SM patterns can effectively reduce the contents of soil heavy metals, showing a preferable soil remediation effect.Meanwhile, the different planting patterns have a significant effect on the composition of the soil microbes. The soil microbial community structure and the community diversity have undergone significant changes. The SM and IMS planting patterns are both beneficial to the increase of soil bacterial diversity, and the SM is relatively more abundant. Soil microbiota plays an important role in the ecological restoration of heavy metal contaminated soil, and indication of the tolerance and sensitivity of heavy metals.

Key words: moso bamboo, Sedum plumbizincicola, phytoremediation, heavy metal, contaminated soil, bacterial community