Objective  Structure and diversity of the microbial communities in the rhizosphere and non-rhizosphere soils on lots grown with different mangrove plants were studied for improved protection and restoration of the ecosystem.

  Methods  Metagenomic DNAs were extracted from the rhizosphere and field soils on Kandelia obovata, Avicennia marina, Aegiceras corniculatum lots and the field soil at an open lot for Illumina NovaSeq sequencing to determine the microbial community structure and diversity.

  Results  ① A total of 39 phyla, 55 classes, 126 orders, 244 families, and 511 genera of microbes were identified in the soils. There were more OTUs in the non-rhizosphere field soils, as well as higher number of species and diversity index, than in the rhizosphere soils. ② In the 4 field soils, the greater than 60% relative abundances of Proteobacteria were significantly dominant in the communities. Firmicutes and Fusobacterium were more abundant on the lot at K. obovate field; Proteobacteria at A. corniculatum field; and Bacteroidetes at A. marina field. At phylum level, Bacillus was slightly more in the field soils, but Bacteroidetes less, than in their rhizosphere counterparts. ③ The PCA analysis indicated the microbial compositions of the rhizosphere soils at the A. corniculatum and A. marina fields to be similar, and the corresponding COG categories of communities in rhizosphere soils roughly the same.

  Conclusion  The microbial communities in the non-rhizosphere field soils were more diverse than in the rhizosphere soils at the lots of various mangrove plants. The major functional microbes in the communities differed by the mangrove variety that grew on the soil.