Determination of Dominant Phyllosphere Microbial Community in Rubber Trees with Powdery Mildew

Abstract Background Rubber tree powdery mildew is an important fungal leaf disease of rubber tree caused by obligate parasitic bacteria. It is one of the most important diseases in rubber planting areas around the world. The pathogen of rubber tree powdery mildew was previously named Oidium heveae, and its pathogen name is currently Erysiphe quercicola. Leaf-associated microbiomes are currently a new and hot research field for molecular ecology, and the biomass in plant ecosystems is also very large and the biological community is extremely rich. Results This study used high-throughput sequencing and other molecular techniques to analyze the structure and diversity of the dominant fungi and bacteria communities of rubber tree leaves in four representative rubber-producing areas in Hainan Province, China (BS, DZ, WN, WZS) after white powder disease occurred. It was found that the dominant bacterial phyla in the four regions were Cyanobacteria, Proteobacteria and Actinobacteria, and the dominant bacterial genus was Cyanobacteria. The dominant fungal phyla in the four regions were Ascomycota, Fungi_unclassified and Basidiomycota.There is significant difference in fungal community composition and relative abundance at genus levels between different areas. We explored the effect of rubber tree powdery mildew on its phyllosphere microbes found that in the same area, there is little difference in community structure between healthy leaves and grade 3 diseased leaves, which only affect the community abundance, while there is significant difference in community composition of different areas. This conclusion also confirms that in the harsh phyllosphere environment, rubber tree phyllosphere microbes need to maintain a good symbiotic relationship with hosts and pathogenic bacteria for surviving and evolving. Conclusions This study analyze the structure and diversity of the dominant fungi and bacteria communities of rubber tree leaves in four representative rubber-producing areas in Hainan Province, China after white powder disease occurred. This project the first time to study the influence of Erysiphe on leaf microorganisms of rubber trees. The conclusion confirms that in the harsh phyllosphere environment, rubber tree phyllosphere microbes need to maintain a good symbiotic relationship with hosts and pathogenic bacteria for surviving and evolving.