Assembly of microbial communities is the result of neutral and selective processes. However, the relative importance of these processes is still debated. Microbial communities of flowers, in particular, have gained recent attention because of their potential impact to plant fitness and plant-pollinator interactions. However, the role of selection and dispersal in the assembly of these communities remains poorly understood. We evaluated the role of pollinator-mediated dispersal on the contribution of neutral and selective processes in the assembly of floral microbiomes of the yellow monkeyflower (Mimulus guttatus). We sampled flowers in the presence and absence of pollinators within five different serpentine seeps in CA and obtained 16s amplicon data on the epiphytic bacterial communities. Consistent with strong micro-environment selection within flowers we observed significant differences in community composition across floral organs and only a small effect of geographic distance. Pollinator exposure affected the contribution of environmental selection and depended on the rate and “intimacy” of interactions with flower visitors. This study provides evidence of the importance of dispersal and within-flower heterogeneity in shaping epiphytic bacterial communities of flowers, and highlights the complex interplay between pollinator behavior, environmental selection and additional abiotic factors in shaping the epiphytic bacterial communities of flowers.

README: Data from: Floral organs act as environmental filters and interact with pollinators to structure the yellow monkeyflower (Mimulus guttatus) floral microbiome

https://doi.org/10.5061/dryad.m874vg5

Description of the data and file structure

Files and variables

Environmental covariates

Pollinator data, co-flowering community

PollinatorData.csv : Pollination observations data. Collected by Maria Rebolleda-Gomez and Rebecca Hayes.
- Location: The number of location within seep (see figure 1 of paper, and supplementary table for coordinates).
- Seep: One of the five replicate seeps in the study (BNS, RH1, RHA, RHB, TP9; see figure 1 of paper and supplementary table for coordinates).
- Visits: Number of visits in 15 min.
- Functional group: Functional pollinator categories from Koski et al., 2015: XS- extra-large social bees; LS- Large social bees; SB- small solitary bee; MB- medium solitary bee; LB- large solitary bee (pollen on body); LL- large solitary bee (pollen on legs); BF- bee fly; SF- small syrphid fly; LF- large syrphid fly; FL- other flies; LE- moths and butterflies; BE- beetles; VE- wasps; OT- other.
- Mimulus: If pollinator visited Mimulus or not “No”. If it did visit a M. guttatus flower it was recorded as either “In” if it went inside the flower “In” or stayed “Out”.
- Hour: Time of the day at which the observation was finished.
- Block: There were two blocks done almost a week apart from each other, sequencing samples were collected together with the second block.
- Time: 1-morning; 2-afternoon
- Day: Date in Julian
FlowerAbundance_170510.csv : Observations of co-flowering community on May X-Y. Initial days of the experiment around the time I set the pollinator exclusion cages.
- Columns indicate the different locations: The first three letters are the seep identifier see figure 1 of paper , and supplementary table for coordenates).
- Rows indicate the flowering species. Species are in codes of four letters (see species code file).
FlowerAbundance_170516_Block2.csv : Observations of co-flowering community on May X-Y. Around the time I sampled flowers in the field. Rows and columns as above.

Sample ID key

Sample that corresponds to the file ID in the demultiplex samples from ARGONNE.

MIGU_metadata.txt

Data about the samples:

SampleID: same as in sequences and OTU tables
BarcodeSequence: from sequencing
LinkerPrimerSequence: from sequencing
BarcodePlate: Number of sequencing plate
Well: Well in plate for sequencing
Seep: Seep codes (BNS, RH1, RHA, RHB, TP9; see figure 1 of paper and supplementary table for coordenates).
Loc: Location within seep (1-3, or 1-4; see figure 1 of paper and supplementary table for coordenates).)
StigmaOpen: Number of flowers with open stigmas in sample
Pollinator: Pollinator treatment (NP-No pollinator (pollinator exclusion); WP- with pollinators (control))
Organ: Where did the sample come from? Style, Anthers (Stamens), Petals, Community, Soil or Leaves.
Type: Endo (endophytes, sequence after wahing and then lysing tissue), Wash (sequenced after washing the sample)
Description: Seep_Location_Treatment_Organ_Type

Locations.csv

Coordinates of our seeps and locations.

Data from: Floral organs act as environmental filters and interact with pollinators to structure the yellow monkeyflower (Mimulus guttatus) floral microbiome

Data files

Abstract