Divergence of Phyllosphere Microbial Communities Between Females and Males of the Dioecious Populus cathayana

Abstract

Females and males of dioecious plants have evolved sex-specific characteristics in terms of their morphological and physiological properties. However, the differentiation of phyllosphere microbiota in dioecious plants remains largely unexplored. Here, the diversity and composition of female and male Populus cathayana phyllosphere bacterial and fungal communities were investigated using 16S rRNA/ITS1 gene–based MiSeq sequencing. The divergences of bacterial and fungal community compositions occurred between females and males. Both females and males had their unique phyllosphere bacterial and fungal microbiota, such as bacterial Gemmata spp. (5.41%) and fungal Pringsheimia spp. (0.03%) in females and bacterial Chitinophaga spp. (0.009%) and fungal Phaeococcomyces spp. (0.02%) in males. Significant differences in the relative abundance of phyla Proteobacteria and Planctomycetes bacteria and phyla Ascomycota and Basidiomycota fungi (P < 0.05) were also found between females and males. Some bacterial species of genera Spirosoma and Amnibacterium and fungal genera Venturia, Suillus, and Elmerina spp. were significantly enriched in males (P < 0.05). In contrast, levels of fungal genera Phoma and Aureobasidium spp. were significantly higher in females than in males (P < 0.05). The mineral, inorganic, and organic nutrients content contributed differently to the divergence of female and male phyllosphere microbial communities, with 87.08 and 45.17% of the variations being explained for bacterial and fungal communities, respectively. These results highlight the sexual discrimination of phyllosphere microbes on the dioecious plants and provide hints on the potential host-associated species in phyllosphere environments.