Fig. 3. Phenotypic consequences of growth in four modified
environmental conditions for Lemna minor, with and without its natural
microbiome. A) Photo of a single genotype grown in four environmentalconditions without the microbiome. B) Variation in frond area
(mm2) C) Variation in Root length (mm). Each box and
whisker represent the variation among 8 independent populations (3
replicate flasks were averaged for each of the 8 genotypes).
Boxes represent the upper and lower quartiles, whiskers represent max
and min values, and outliers are shown as points.
Average colony size, i.e., the number of attached fronds, changed
markedly with the abiotic environment (F3,128=162.49,
p<0.001), with smaller colonies in high nutrient and light
conditions and larger colonies when these resources are in shorter
supply. We regressed colony size on growth rate and found that the
slower growing the population, the greater the number of fronds that
remain attached (F3,188=96.7, p<0.001, m=
-36.7, R2=0.60) (Fig. 4). However, this also depended
on the presence of the microbiome. In general, the presence of the
microbiome decreased colony size. Although the slope of the relationship
between colony size and growth rate was the same whether the microbiome
was present or absent, the intercept was significantly different
(p=0.001), such that for the same growth rate, plants with their intact
microbiome exhibited smaller colony sizes (Fig. 4).