Leaf Fungal Microbiome Is Modulated by Interspecific Hybridization Events Between Coffea Species

Increasing attention has been given to the host phylogeny and domestication roles in shaping plant-associated microbiomes. However, the interspecific effects of hybridization on microbial communities remain poorly understood. We investigated the effects of interspecific hybridization on the composition, diversity, ecological organization, and co-occurrence patterns of leaf-associated fungal communities in five Coffea species and hybrids between C. arabica and the other four species in the same habitat. Beta-diversity analyses showed a differentiation among host genotypes. Assignment of fungal genera to guilds indicated that fungal communities were dominated by pathogen-saprotrophs. Interestingly, Coffea stenophylla, a genetically distinct species within the same broader evolutionary clade, exhibited a higher relative abundance of pigmented yeasts and saprotrophs compared to C. arabica and other Coffea species analyzed. Fungal communities associated with hybrids were more similar to those of C. arabica than to the other parental species, indicating asymmetric contributions of parental traits to the colonization of the hybrids' phylloplane. A co-occurrence network revealed that neutral associations were more prevalent in Coffea hybrids than in Coffea species. These results indicate that while dominant fungal taxa are largely conserved across Coffea species and hybrids, interspecific hybridization is associated with the reorganization of the ecological relations in a fungal community. Overall, host genetics and hybridization-related traits influence the assembly and ecological organization of leaf-associated fungal communities in Coffea.