Factors affecting the diversity of leaf bacterial communities in rubber plantations in Xishuangbanna and Hainan

To understand the diversity of the leaf microbiome in tropical rubber forests, high- throughput sequencing technology was utilized to analyze the composition and diversity of the leaf microbiome in two locations, and to explore the interactions between the leaf microbiome and environmental factors. The results showed that: In terms of species composition, the dominant phyla in Hainan and Xishuangbanna were Firmicutes and Proteobacteria, respectively; Bacillus and Methylobacterium were the dominant genera in both Hainan and Xishuangbanna.Principal coordinate analysis(PCoA) based on the Bray-Curtis distance index indicated that the similarity of leaf microbiomes from different geographical locations is low, with significant differences in species composition and structure, which was confirmed by permutational multivariate analysis of variance(PERMANOVA).In terms of diversity, the Shannon index of the leaf microbiome in Xishuangbanna was significantly higher than that in Hainan(P < 0.001).In terms of influencing factors, redundancy analysis(RDA) revealed that the sampling site has the greatest impact on the beta diversity of the leaf microbiome, being the most significant factor affecting the beta diversity of the leaf microbiome.Correlation analysis indicated that the dominant genera and phyla of the rubber forest were significantly positively correlated with nitrogen content in the leaves. Linear regression analysis found that the diversity index was significantly correlated with phosphorus content and average annual temperature in the leaves. In summary, there are significant differences in the composition and diversity of the leaf microbiome between Hainan and Xishuangbanna rubber forests. Average annual temperature and nitrogen content in the leaves are the main environmental factors affecting the composition of the leaf microbiome, while average annual temperature and phosphorus content in the leaves are the key factors affecting the diversity of the leaf microbiome.