Skip to main content

Table 3 Statistical analysis of competitive success of vir9 isolates in the field competition experiments

From: Tracking costs of virulence in natural populations of the wheat pathogen, Puccinia striiformis f.sp.tritici

Source

denm.

DF

MD

F

Pr > F

Year

1+3–5

1,1

1.13

0.09

0.8072

Cultivar

2+3–5

1,1

10.71

0.88

0.5203

Pair

1+2–5

3,4

47.80

15.57

0.0114

Year*Pair (1)

4

3,3

1.84

3.23

0.1807

Cultivar*Pair (2)

4

3,3

1.45

2.54

0.2321

Year*Cultivar (3)

4

1,3

11.36

19.93

0.0209

Year*Cultivar*Pair (4)

5

3,16

0.57

0.57

0.6438

Residual (5)

 

16

1.00

-

-

  1. Based on a logistic regression, Analysis of Deviance tested for effects of pair (Avir/vir), host cultivar and year on final frequencies of vir9 isolates. Analogous to Analysis of Variance, mean deviances (MD = 2.log-likelihood ratio/DF) were used to calculate quasi-F values. The denominator (denm.) column indicates the error terms used for the F-tests; where necessary, linear combinations of different model factors were made [69]. The DF column indicates the numerator and denominator degrees of freedom. All factors were considered as random effects. Model fitting was analogous to SAS-type II model fitting [68].