Table 3.
Generalized linear model analysis of the frequency of pvr2 3 resistance breakdown (RB) with four explanatory variables linked to evolutionary forces characterizing Potato virus Y (PVY) populations in the different pepper genotypes. The explanatory variables are the differential selection σ r, the effective population size during plant colonization (N e), the effective population size at inoculation (N e inoc) and viral accumulation (VA). A stepwise selection procedure, both forward and backward, was applied using Akaike’s information criterion. The resulting model presented had a null deviance of 2264.3 on 83 degrees of freedom, whereas the residual deviance was 1287.7 on 75 degrees of freedom. McFadden’s R 2 was 0.40.
| Explanatory variable | Estimate | Standard error | z value | P value† |
|---|---|---|---|---|
| Intercept | 4.71 | 0.60 | 7.81 | 6e‐15*** |
| σ r | −56.32 | 4.02 | −14.03 | <2e‐16*** |
| N e | −3.6e‐02 | 6.7e‐03 | −5.37 | 8e‐08*** |
| VA | −2.92 | 0.40 | −7.26 | 4e‐13*** |
| σ r × VA | 28.44 | 2.97 | 9.56 | <2e‐16*** |
| N e × N e inoc | 1.5e‐03 | 2.9e‐04 | 5.30 | 1.1e‐07*** |
| N e × VA | 7.8e‐03 | 1.8e‐03 | 4.26 | 2.1e‐05*** |
| N e inoc × VA | 2.5e‐02 | 9.3e‐03 | 2.73 | 0.0064** |
†** and *** correspond to 0.01 and 0.001 significance thresholds, respectively.