Host genotype strongly influences the phyllosphere fungal communities of Mussaenda pubescens var. alba

Phyllosphere fungi have high species diversity and play an important role in plant fitness and ecosystem functioning, but the relationship between host plant genotype and phyllosphere fungal community is still poorly understood. In this study, we examined fungal community of leaves of Mussaenda pubescens var. alba across a regional scale using Illumina MiSeq sequencing of ITS2 sequences and characterized genotype and genetic structure of the host plants employing microsatellite techniques. A total of 1575 taxonomic operational units (OTUs) of fungi were obtained at a 97% sequence similarity level, dominated by the members of Dothideomycete and Eurotiomycetes. The OTU richness was strongly affected by plant genotype and geographic distance. The fungal community composition was significantly structured mainly by plant genotype, less by geographic distance and altitude. Furthermore, a significant genetic differentiation was detected among host plant populations, and plant genetic distance showed a significantly positive relationship with the fungal community dissimilarity. This study highlights that intraspecies host genetic identity acts as a primary driver in shaping phyllosphere fungal community at the regional scale.