Consistent root microbiomes across contrasting habitats in a wild perennial vine

While we are beginning to understand that the plant microbiome is important for plant health, we still lack information about how plant microbiomes are shaped across environments and how they influence plant performance, in particular, in wild study species. Here, we examined the root microbiota of the perennial vine Solanum dulcamara, a wild relative of potato with an unusually wide ecological amplitude. Using amplicon sequencing, we characterized root communities of bacteria, fungi, and arbuscular mycorrhizal fungi in eight populations across four habitat types (beach, forest, rural, urban) and investigated the link with habitat and plant performance. We found significant differences in the composition and diversity of the root microbiota across habitats and populations, but a core set of taxa (61% of all bacterial and 73% of all fungal) made up the majority of the root microbiome. The microbiome composition was connected to soil pH and plant nutrients. Even though the investigated populations differed in herbivory and plant performance, the association between plant performance and microbial composition was weak. In conclusion, our results suggest that wild species can have similar root microbiomes across widely different habitats, and that plant performance is not always directly linked to the plant microbiome.