Mycorrhizal abundance affects the expression of plant resistance traits and herbivore performance
Supplementary Material
S1. AMF treatments consisted of live and autoclaved whole fungal inoculum (homogenized root pieces, spores, hyphae) from Glomus
etunicatum, Scutellospora fulgida, or a 1:1 mix of the two species. Phenotype experiment plants describe the total number of
seedlings used to assess plant phenotype. Total Caterpillar Replicates is the total number of caterpillars (1/plant) used to assess plant
resistance on an equal number of plants of each treatment (1 caterpillar/plant). Genotype refers to the 5 milkweed families used in
experiments, AMF refers to the 3 AMF treatments described above, and N refers to the number of replicates. Spore densities were
assessed, but not reported, since root fragments and hyphae also contributed substantially to mycorrhizal infectivity.
Treatment
0
1
2
3
4
5
6
7
8
9
10
Live Inoculum
(mL/pot)
0
0.5
1
2
5
10
25
40
60
100
150
Autoclaved Inoculum
(mL/pot)
150
149.5
149
148
145
140
125
110
90
50
0
Phenotype Experiment
Plants
10 (N=2/genotype)
30 (N=2/genotype/AMF)
30 (N=2/genotype/AMF)
30 (N=2/genotype/AMF)
30 (N=2/genotype/AMF)
30 (N=2/genotype/AMF)
30 (N=2/genotype/AMF)
30 (N=2/genotype/AMF)
30 (N=2/genotype/AMF)
30 (N=2/genotype/AMF)
30 (N=2/genotype/AMF)
Total Caterpillar
Replicates
20 (N=4/genotype)
0
60 (N=4/genotype/AMF)
0
60 (N=4/genotype/AMF)
0
60 (N=4/genotype/AMF)
0
60 (N=4/genotype/AMF)
0
60 (N=4/genotype/AMF)
S2. AICc values comparing linear, saturating, and logistic models to root colonization of Asclepias syriaca by arbuscular mycorrhizal
fungi Glomus etunicatum, Scutellospora fulgida, and a mix of the two species. Inoculum densities follow those given in
Supplementary Table 1.
Null
Linear
Saturating
Logistic
GE
-42.0
-89.2
-110.4
-87.3
SF
-24.6
-69.7
-71.9
-64.0
Mix
-94.9
-99.2
-132.4
-102.3
0.2
0.2
0.4
0.6
0.8
0.0
R2 = 0.146
0.1
0.2
0.3
0.4
0.5
0.6
0.1
0.2
0.3
0.4
0.5
0.6
0.1
0.2
0.3
0.4
0.5
0.6
0.5
0.6
0.1 0.3
0.3
f)
0.1
0.0
g)
h)
0.2
0.4
0.6
0.8
0.0
R2 = 0.0422
i)
0
0.0
2
2.0
4
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
0.0
R2 = 0.0919
k)
j)
0.2
0.4
0.6
0.8
R2 = 0.275
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
0.0
p)
q)
0.4
0.6
0.8
R2 = 0.0677
0.2
0.4
0.0
0.0 1.5 3.0
n)
0.2
0.6
R2 = 0.0748
0.2
0.3
0.4
0.1
0.2
0.3
0.4
0.5
R2 = 0.0283
r)
2
2
6
5
0.1
o)
0.0
10
m)
G. etunicatum
R2 = 0.0659
l)
0.005
0.0
0.0 1.5 3.0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
0.0
0.010
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
8
0.0 1.5 3.0
0.8
0.6
e)
6
Foliar Cardenolides
R2 = 0.0376
c)
0.2
0.8
0.2
d)
0.020
%P
0.0
0.10 0.30
0.0 1.5 3.0
Latex
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
2
Foliar Trichomes
R2 = 0.0125
b)
0.000
SLM
a)
0.020
AG Biomass
S3. Best-fit lines relating the degree of AMF colonization of Glomus etunicatum,
Scutellospora fulgida, or a mix of the two species to the expression of plant nutrition and
resistance traits in Asclepias syriaca plants. Each point represents a plant individual.
Traits include a-c) aboveground (AG) biomass, d-f) % foliar phosphorus, g-i) latex
exudation (mg), j-l) specific leaf mass (SLM), m-o) total foliar cardenolides, and p-r) the
density of foliar trichomes on the bottom surface of the leaves.
0.0
0.2
0.4
0.6
0.8
S. fulgida
Proportion of Plant Root Colonized by AMF
0.0
0.1
0.2
0.3
Mix
0.4
0.5
0.6
S4. Proportion of total variance in the expression of Asclepias syriaca nutrient and resistance traits explained by AMF abundance,
AMF species identity, plant genotype, the presence or absence of AMF, and interactions between genotype (G) and all other AMF
predictors, or the variance remaining (error). Numbers indicate the proportion of variance explained by each significant predictor
(p<0.05), calculated by dividing the sums of squares explained by each factor by the total variance in each trait, among all phenotype
assay plants (a-f).
a ) AG Biomass
b)%P
error
c ) Latex
error
G X Presence
0*
G X Presence
G x Abundance
0*
G x Abundance
error
0.02 *
0.03 *
G X Species
0.02 *
G X Species
0*
G X Species
0*
AMF Presence
0*
AMF Presence
Plant Genotype
0.01 *
Plant Genotype
0*
Plant Genotype
0.93 *
AMF Species
0.2
0.4
0.6
0.8
1.0
1.2
0.0
d ) SLM
0.2
0.4
0.6
0.8
0*
0.01 *
G X Presence
0.02 *
G x Abundance
0.02 *
G X Species
0.02 *
AMF Presence
0.03 *
0.04 *
Plant Genotype
0.0
0.2
0.02 *
0.01 *
0.6
0.8
1.0
0.0
0.2
0.17 *
0.4
0.51 *
AMF Species
0.55 *
AMF Abundance
0.4
0.8
0.06 *
Plant Genotype
0.35 *
AMF Species
0.16 *
AMF Abundance
0*
G X Species
Plant Genotype
0.6
f ) Trichome Density
0.01 *
AMF Presence
0.4
error
G X Presence
0*
0.02 *
0.2
G x Abundance
AMF Presence
AMF Species
0.0
e ) Foliar Cardenolides
0.02 *
G X Presence
0.46 *
0.04 *
AMF Abundance
error
G x Abundance
0.3 *
0.1 *
AMF Species
0.12 *
AMF Abundance
error
G X Species
0.44 *
AMF Species
0.04 *
0.0
0.05 *
G x Abundance
AMF Presence
AMF Abundance
0*
G X Presence
0.01 *
0.6
0.18 *
AMF Abundance
0.8
Proportion of Variance Explained
0.0
0.2
0.4
0.6
0.8