Models description and selection criteria.

aSix models are obtained by crossing 2 hypotheses regarding the genetic differentiation of virus populations between plants (D1 and D2) with 3 hypotheses regarding the competition issue between virus variants (C1 to C3). They include four to 14 parameters and were compared using Akaike information criterion (AIC) and Bayesian information criterion (BIC) to identify the model that is best supported by the data.bThe process of genetic differentiation of the virus populations between plants, described by the scale parameter θ of a Dirichlet-multinomial distribution, was allowed either to be constant (θs = θ) or time varying (, for the five sampling dates ).cThe process of virus competition within plants included the intrinsic rates of variant increase (given that ) as parameters but might undergo one of three hypotheses specifying the type of Lotka-Volterra competition coefficients .d−2log(Likelihood).