Supplemental Tables
Table S1. Additional information about Benchmark Study locations and samples taken from field
margins to test for relationships between the occurrence of GR C. canadensis, field history, and location.
N is the number of sampled plants with germinable seed; PCA is the resistance score based upon the
Principle Components Analysis axis 1; DA is the percentage of resistant plants out of the total sampled;
PHZ is USDA Plant Hardiness Zone; STATE is the abbreviation for US state.
Field
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
GR1
GR2
GS1
GS2
N
8
8
10
10
11
10
10
9
10
10
10
10
10
10
10
11
10
.
.
.
.
PCA
20.62
14.67
13.78
-121.81
27.46
-62.24
36.77
50.44
25.79
13.36
5.37
-0.52
-31.43
35.25
-58.54
34.65
-18.19
-78.18
-37.40
55.03
30.22
DA
44
38
38
100
19
100
5
22
35
15
37
45
70
16
100
10
60
100
100
0
0
Latitude
41.376667
40.756180
42.820372
37.286280
37.356018
38.525000
40.509210
42.263690
42.220624
40.469800
41.120510
38.614130
37.917121
42.496604
38.293280
38.437096
38.236420
37.812439
37.823231
38.517243
37.698086
Longitude
-85.152778
-97.101380
-101.621453
-89.471338
-89.400530
-87.576111
-97.036620
-96.764638
96.919528
-97.131570
-101.056523
-88.438435
-89.173774
-97.068920
-89.487000
-89.045932
-90.336652
-89.304061
-89.301561
-89.839331
-89.241819
PHZ
5
5
4
6
6
6
5
4
4
5
5
5
6
4
6
5
5
6
6
6
6
STATE
IN
NE
NE
IL
IL
IN
NE
NE
NE
NE
NE
IL
IL
NE
IL
IL
IL
IL
IL
IL
IL
Table S2. Descriptive statistics for independent variables, Principal Component Analysis (PCA) axis 1
scores and Discriminant Analysis (DA) percentage of glyphosate-resistant (GR) C. canadensis plants in
field margins, and environmental variables associated with field sites (n=17).
Minimum
Independent variables
PCA axis 1 scoresa
DA percent resistance
Local effects
Latitude
Longitude
USDA plant hardiness zones
Management practices
Crop rotation
GR trait rotation
Tillage
2006
2007
2008
Herbicide diversity
Grower managed (AG1) field half
2006
2007
2008
a
Descriptive Statistics
Maximum
Mean or %
SE
-121.81
0.10
50.44
1.00
-0.86
0.46
10.89
0.08
37.28628
-101.621
4
42.82037
-85.1528
6
39.92347
-93.1049
5.117
0.468
1.246
0.189
0 - no
0 - no
1 - yes
1 - yes
65% - yes
35% - yes
-
0 - no
0 - no
0 - no
1 - yes
1 - yes
1 - yes
18% - yes
29% - yes
12% - yes
-
0 - low
0 - low
0 - low
1 - high
1 - high
1 - high
24% - high
53% - high
53% - high
-
Abbreviations: PCA, principle component analysis, was performed on the variables by mother plant,
using a variance covariance cross-products matrix, and each mother plant was assigned a score for axis
loadings within the PCA. Mother plant scores were averaged by field and these were used as dependent
variables for further analyses; DA, discriminant analysis, is a type of canonical variates analysis, where a
set of linear functions of the predictor variables is constructed and used to classify unknown samples.
Two GR and two GS C. canadensis populations were used as the reference set, and the classification
variable selected was the visual rating at 14 DAT for the 1X rate. This variable had a high component
loading for PCA axis 1 and was indicated as a significant predictor of glyphosate resistance for runs 1 and
2 in the DA; USDA, United States Department of Agriculture; GR, glyphosate-resistant; GS, glyphosatesusceptible; SE, standard error.
Table S3. Summary of correlation and mixed model analyses of independent variables as related to
Principal Component Analysis (PCA) axis 1 scores and Discriminant Analysis (DA) percentage of
glyphosate-resistant (GR) C. canadensis plants in field margins. Significance is
indicated by *P<0.05, **P<0.01 and ***P<0.001.
Measures of glyphosate-resistant C. canadensis in field
margins
a
Test type
PCA scoresb
DA % resistance
Local effects
Latitude
R17=
Longitude
R17=
USDA plant hardiness zones
F2, 14=
Management practices
Crop rotation
F1, 15=
GR trait rotation
F1, 15=
Crop type
2006
F1, 15=
2007
F1, 15=
2008
F1, 15=
Tillage
2006
F1, 15=
2007
F1, 15=
2008
F1, 15=
Herbicide diversity
Grower managed (AG1) field half
2006
F1,15=
2007
F1,15=
2008
F1,14=
a
0.62 **
-0.44
8.65 **
-0.45
0.38
6.37 **
1.05
0.62
0.27
3.05
3.08
0.04
3.08
3.10
1.65
3.10
0.08
6.06 *
0.60
1.75
7.16 *
2.56
0.43
5.67 *
1.68
0.14
7.13 *
0.24
Test type: The values indicated represent a Pearson correlation coefficient, R, with number of samples,
or an F-statistic, with numerator and denominator degrees of freedom.
b
Abbreviations: PCA, principle component analysis, was performed on the variables by mother plant,
using a variance covariance cross-products matrix, and each mother plant was assigned a score for axis
loadings within the PCA. Mother plant scores were averaged by field and these were used as dependent
variables for further analyses; DA, discriminant analysis, is a type of canonical variates analysis, where a
set of linear functions of the predictor variables is constructed and used to classify unknown samples.
Two GR and two GS C. canadensis populations were used as the reference set, and the classification
variable selected was the visual rating at 14 DAT for the 1X rate. This variable had a high component
loading for PCA axis 1 and was indicated as a significant predictor of glyphosate resistance for runs 1 and
2 in the DA; USDA, United States Department of Agriculture; GR, glyphosate-resistant; GS, glyphosatesusceptible.
Table S4. General linear mixed model analyses, testing measures of reproductive output by population in
the agrestal and ruderal habitats. Num, Den df = numerator degrees of freedom and denominator
degrees of freedom, respectively.
Agrestal habitat
Num, Den df
Ruderal habitat
F
P
9.30
0.0002
3,23
9.13
3,22
1.58
Num, Den df
F
P
3,8
0.42
0.74
0.0004
3,8
0.70
0.58
0.22
3,7
1.40
0.31
a) Number of capitulae per plant
Population
3,26
b) Number of seed per capitulum
Population
c) Weight per seed
Population
Supplemental Figures
60
40
PCA Axis 1 Score
20
0
-20
-40
-60
-80
-100
R17=0.62, p=0.008
-120
-140
37
38
39
40
41
42
43
44
Latitude (°N)
Figure S1. Correlation analysis of principle component analysis (PCA) axis 1 scores of GR C. canadensis in
2008 field margins by field with latitude, where the most negative scores are correlated with lower
latitudes, indicating greater and more variable occurrence of resistance at lower latitudes.
Percentage of flowering individuals
25
Agrestal
Ruderal
20
15
10
5
0
GR1
GR2
GS1
GS2
Population
Figure S2. Percentage of individuals reaching the flowering stage by population and habitat, based on
survivorship curve data for flowering stage. Abbreviations labeling the x-axis indicate plants from the
four populations: GR1 – GR population 1, GR2 – GR population 2, GS1 – GS population 1, GS2 – GS
population 2.
Maximum percentage of herbivory
60
a
50
40
ab
b
ab
30
20
10
0
GR1
GR2
GS1
GS2
Population
Figure S3. Maximum estimate of herbivory (percentage of leaves damaged / individual) for individuals in
the ruderal habitat. Mean values with the same letter are not significantly different (α = 0.05).
Abbreviations labeling the x-axis indicate plants from the four populations: GR1 – GR population 1, GR2
– GR population 2, GS1 – GS population 1, GS2 – GS population 2.