关键词: 报春苣苔, 根系微生物, 土壤微生物群落, 16S rRNA测序

Abstract: In order to analyze the rhizosphere microbiome of karst calciphilous plant Primulina tabacum, this paper compared the differences of microbiome between Primulina tabacum’s rhizosphere/bulk soil, analyzed the relationship between rhizosphere/bulk soil’s microorganisms and soil’s content of soluble calcium at the same time, aimed to provide new information for calciphilous mechanism of Primulina tabacum’s root system. High-throughput sequencing 16 s rRNA V4 and ITS1 sequence were used to comparatively analyze the structural differences of rhizosphere/bulk soil microbiome of calciphilous plant Primulina tabacum, and CCA and Spearman correlation coefficient were used to analyze the relationship between the soil’s content of soluble calcium and Primulina tabacum’s rhizosphere/bulk soil microbiome. The results showed that: Primulina tabacum’s rhizosphere soil microbiome contained 41 bacteriophytas and 6 eumycotas, and those dominant ascomycotas among bacteria were Proteobacteria, Actinobacteria and Acidobacteria, which occupied more than 64% of the total. Main fungus were Ascomycota, Basidiomycota and Zygomycota, which occupied more than 99% of the total. Compared with bulk soil, the abundance of Acidobacteria flora increased significantly in rhizosphere soil, while the abundance of Proteobacteria and Gemmatimonadetes decreased markedly, and the growth was restrained. Both Primulina tabacum’s rhizosphere and bulk soil microbiome were very abundant, which contained 569 genera of bacteria and 276 genera of fungi. The Shannon, Chao1 and ACE’s α- diversity index of Primulina tabacum’s rhizosphere bacterias were significantly higher than that of bulk soil, which showed Primulina tabacum’s rhizosphere bacteria flora species numbers higher than that of bulk soil, and that Primulina tabacum’s rhizosphere fungal PD whole tree index was significantly lower than bulk soil, showed that group feature of bacterias flora in Primulina tabacum’s rhizosphere was lower than bulk soil. Soil’s soluble calcium explained only 16.93% of microbiome structure, and Monte Carlo permutation test showed that the soil soluble calcium was not remarkably correlative with the species distribution. Further analysis found that only Hydrogenedentes was remarkably correlative with soluble calcium. The differences of microbiome between Primulina tabacum’s rhizosphere soil and bulk soil were significant, and the correlation to soil’s soluble calcium was limited. The composition of Primulina tabacum’s rhizosphere microbiome species was abundant, and Primulina tabacum’s root was advantageous to the rhizosphere bacteria’s community diversity.

Key words: Primulina tabacum, root microorganism, soil microbiota, 16S rRNA sequencing