Relationship between the bacterial community and environmental factors in the rhizosphere soil of wild morels in Gansu

Abstract:

[Background] Morel (Morchella spp.), a worldwide species, has important scientific and economic value. However, there are few studies on the correlation among elements of its rhizosphere microecosystem. [Objective] We explored bacterial community-soil physico-chemical property and bacterial community-enzyme activity relationships in rhizosphere soil of wild morels in different areas of Gansu Province. [Methods] With Illumina MiSeq technology, the bacterial community structure in the rhizosphere soil was measured and then bacterial diversity was analyzed. On this basis, the above relationships were elucidated.[Results] The pH of rhizosphere soil decreased with the rise of elevation, but the major and minor elements and enzyme activity varied irregularly with sampling site. Proteobacteria and Actinobacteria dominated at all the sampling sites. The bacterial operational taxonomic units (OTUs) and Shannon's diversity index at LX were more higher than those at other sites. Redundancy analysis (RDA) showed that Proteobacteria, Bacteroidetes, and Verrucomicrobia were positively correlated with soil nutrients, soil water content, and elevation, but negatively correlated with soil pH and content of Ca and Mg. Actinobacteria, Acidobacteria, and Planctomycetes were in positive correlation with Mg content, soil urease, and arylsulfatase, but in negative correlation with the content of Fe, Se, and available potassium, soil dehydrogenase, and alkaline phosphatase. Gemmatimonadetes and Chloroflexi were positively correlated with soil pH and Ca content, whereas Firmicutes showed positive correlation with the content of Fe and Se. [Conclusion] We clarified the correlation among elements in the rhizosphere soil microecosystem of wild morels in Gansu, laying a theoretical foundation for efficient cultivation of morel.

Key words:wild morels;rhizosphere soil;environmental factors;bacterial community;high-throughput sequencing