Search

Premise Methods Results Conclusions Intraspecific variation in flower microbiome composition can mediate pollination and reproduction, and so understanding the community assembly processes driving this variation is critical. Yet the relative importance of trait‐based host filtering and dispersal in shaping among‐species variation in floral microbiomes remains unknown.Within two clades of Brassicaceae, we compared diversity and composition of floral microbiomes in natural populations of focal nickel and selenium hyperaccumulator species and two of their non‐accumulating relatives. We assessed the relative strengths of floral elemental composition, plant phylogenetic distance (host filtering), and geography (dispersal) in driving floral microbiome composition.Species in the nickel hyperaccumulator clade had strongly divergent floral microbiomes, the most of that variation driven by floral elemental composition, followed by geographic distance between plant populations and, lastly, phylogenetic distance. Conversely, within the selenium hyperaccumulator clade, floral microbiome divergence was much lower among the species and elemental composition, geography, and plant phylogeny were far weaker determinants of microbiome variation.Our results show that the strength of elemental hyperaccumulation's effect on floral microbiomes differs substantially among plant clades, possibly due to variation in elements as selective filters or in long‐distance dispersal probability in different habitats. [ABSTRACT FROM AUTHOR]

Premise: Whole‐genome duplication (neopolyploidy) can instantly differentiate the phenotype of neopolyploids from their diploid progenitors. These phenotypic shifts in organs such as roots and leaves could also differentiate the way neopolyploids interact with microbial species. While some studies have addressed how specific microbial interactions are affected by neopolyploidy, we lack an understanding of how genome duplication affects the diversity and composition of microbial communities. Methods: We performed a common garden experiment with multiple clones of artificially synthesized autotetraploids and their ancestral diploids, derived from 13 genotypes of wild strawberry, Fragaria vesca. We sequenced epiphytic bacteria and fungi from roots and leaves and characterized microbial communities and leaf functional traits. Results: Autotetraploidy had no effect on bacterial alpha diversity of either organ, but it did have a genotype‐dependent effect on the diversity of fungi on leaves. In contrast, autotetraploidy restructured the community composition of leaf bacteria and had a genotype‐dependent effect on fungal community composition in both organs. The most differentially abundant bacterial taxon on leaves belonged to the Sphingomonas, while a member of the Trichoderma was the most differentially abundant fungal taxon on roots. Ploidy‐induced change in leaf size was strongly correlated with a change in bacterial but not fungal leaf communities. Conclusions: Genome duplication can immediately alter aspects of the plant microbiome, but this effect varies by host genotype and bacterial and fungal community. Expanding these studies to wild settings where plants are exposed continuously to microbes are needed to confirm the patterns observed here. [ABSTRACT FROM AUTHOR]