Composition, richness and nonrandom assembly of culturable bacterial–microfungal communities in floral nectar of M editerranean plants

The recent upsurge of interest in the role of floral nectar as a habitat for microorganisms has led to some detailed analyses of nectarivorous yeasts. In contrast, very little is known on the occurrence and diversity of nectar‐dwelling bacteria, and bacterial–fungal interactions within nectar remain unexplored. In this work, we studied both the culturable bacteria and microfungi found in the floral nectar of wild M editerranean plants. In general, bacteria and yeasts were found coexisting in nectar more often than would be expected by chance, and such positive association persisted after accounting for phylogenetic nonindependence of the plant species surveyed. M etschnikowia species were confirmed as the main fungal components of nectar communities, and A cinetobacter was identified as the main bacterial taxa. Finally, individual O perational T axonomic U nits ( OTU s) were found to co‐occur less frequently than predicted by random expectations. There existed, however, some pairwise associations between OTU s that seemed to account for the general pattern of positive bacteria–yeasts coexistence. We conclude that the culturable communities of nectar microorganisms associated with wild M editerranean plants are nonrandom assemblages of bacterial and yeast species.