Abstract
The influence of planted area of replaced host genotype on the types and patterns of nonrandom associations between avirulence loci in the pathogen was examined by a method of sitnulation. The influence of area occupied by replaced genotypes on the difference between observed frequencies obtained with simulations and expected frequencies under the assumption that Inutation to virulence occurs depending on avirulence genes was shown. The replaced genotype is called new genotype (or receptor) and the variety in cultivation before replacement is called old genotype (or donor). The shapes (Figs. I and 2) of curves of differences (x2) between observed values obtained from simulations and expected values from random association varied with the nuniber of susceptibility genes in the new and old host genotypes. Furthermore, fitness values given to the viru-lence genes influenced greatly on the shapes.
