Abstract:

To explore the response of bacterial communities of corn in rhizospheric soil to Cd pollution, we utilized the Illumina MiSeq high throughput sequencing platform, and conducted 16S rDNA amplification analysis on four groups of soil samples with different levels of Cd pollution from Silong Town (Baiyin City, Gansu Pro-vince). The results showed no significant difference in the Chao1 and Shannon indices of soil bacterial samples from these four groups of Cd-polluted samples (p>0.05), indicating that the pollution effect is insignificant. The bacterial abundance of the four sample groups is similar, and the dominant communities are largely the same, i.e., (phylum level) Proteobacteria, Bacteroidetes, Acidobacteria, Chloroflexi and Planctomycetes, and (dominant genera) are Ohtaekwangia, GP4, GP6, Nitrospira and Gemmatimonas. The Ohtaekwangia and Gemmatimonas have high stress resistance, and their relative abundance increases with increasing soil Cd content. In contrast, GP4 and GP6 have low stress resistance, and their relative abundance decreases with decreasing soil Cd content. Cadmium pollution can cause changes in bacterial diversity in the soil, but there is no simple linear relationship between bacterial diversity and Cd content. With increasing Cd content in the environment, soil bacterial diversity generally increases first and then decreases. Soil samples with intermediate pollution level have the highest bacterial diversity.

Key words: bacterial diversity, Cd pollution, corn rhizosphere soil, high-throughput sequencing