BACTERIAL COMMUNITY COMPOSITION AND FUNCTIONS IN RHIZOSPHERE SOIL OF FOUR DECIDUOUS FRUIT TREES

The purpose of this study was to explore the composition of bacterial communities in the rhizosphere soil of four deciduous fruit trees (pomegranate, peach, cherry, and ginkgo) and to study the bacterial community structure and metabolic function of them. 16S rRNA sequencing technology was adopted to analyze the bacterial community structure, and Tax4Fun was employed to predict the metabolic profiles of the bacterial community. The results showed that the Shannon index, Ace index, and Chao1 index values of the ginkgo rhizosphere soil samples were the largest,indicating that the bacterial diversity of ginkgo rhizosphere soil was the highest. 4764 OTUs were identified for bacteria and were classified as 46 phylums, 113 classes, 175 orders, 247 families, 339 genera, and 504 species. Whether at the phylum level, at the order level, or at the genus level, no significant differences in the composition of bacterial communities were detected among the rhizosphere soils of the four deciduous fruit trees. Proteobacteria, Actinobacteria, Bacteroidota, and Acidobacteriota were the most abundant phyla, and Gammaproteobacteria, Bacteroidota, Alphaproteobacteria, and Alphaproteobacteria were the most abundant orders across all samples. The KOs (KEGG orthology) were mainly involved in 6 KEGG level 1 pathways and 35 KEGG level 2 pathways. The relative abundance of these six pathways was not significantly different in rhizosphere soils among the four deciduous fruit trees at the first KEGG level. The main enrichment pathways of microorganism metabolism at the second KEGG level are consistent, mainly in carbohydrate metabolism, amino acid metabolism, energy metabolism, lipid metabolism, nucleotide metabolism, and the metabolism of cofactors and vitamins.