The Compartment and Variety Effects Jointly Shape Pummelo Endophytic Mycobiota

The plant microbiome plays important roles in plant growth and resistance, but its assembly and affecting factors have not been fully studied for most of the agricultural plants. In this study, the endophytic mycobiota of the leaves and roots and the rhizosphere soils of five pummelo varieties were profiled based on the amplicon sequencing of the fungal internal transcribed spacer (ITS). The fungal richness and diversity were significantly different among the compartments, but not among the pummelo varieties. The composition and structure of the endophytic mycobiota of the compartments were significantly different across all five pummelo varieties. These suggest that the variety effect is weaker than the compartment effect, but still significant in shaping the pummelo mycobiota. Specifically, the dominant leaf endophytic fungal taxa (e.g., Fusarium and Zasmidium), and the root selection of fungal genera from the rhizosphere soils, were significantly different among the varieties. And also, the variety effect is more significant in shaping the leaf endophytic mycobiota than those of the roots. Finally, the pummelo varieties also showed some consistent alterations on the endophytic mycobiota, such as the root enrichment of Exophiala species. Our study indicates that the endophytic mycobiota of pummelos is significantly and interactively affected by plant variety and compartment effects, and suggests some fungi of interest for further tests.