Figure 3

Effectplots for epistatic interactions identified between pairs of QTL for the constitutive trichome density (A) and induced trichome density (B) phenotypes in the Hi-0 x Ob-0 mapping population. Each panel shows the mean trichome density phenotype (y axis) for the four possible allele combinations found at two interacting loci. The parental allele at one QTL is indicated on the x axis and the parental allele at the interacting QTL is indicated by the color of the plot points and lines. Panel A shows a large interaction effect for constitutive trichome density between loci on chromosome 1 at 86 cM (HOC1, here labelled 1@86) and on chromosome 4 at 71 cM (HOC4, here labelled 4@71); the highest trichome density is achieved by genotypes where the alleles from the same parent co-occur. Panel B shows an interaction for induced trichome density between loci on chromosome 3 at 47 cM (HOD2; 3@47) and chromosome 4 at 24 cM (HOD3; 4@24). Here, the effect of the chromosome 4 locus appears to be masked by the Ob-0 allele on chromosome 3.