INTERPRETATION OF PERFORMANCES OF HYBRIDS OBTAINED FROM 43 ASPARAGUS PARENT GENOTYPES

The data used were the yields of 231 distinct hybrids grown in long-term multi-site trials (10 yr, 4 sites), resulting from the crossing of 43 genotypes. Genotype-environment interaction was taken into account by means of a factorial regression model previously defined through the varieties used as controls in the trials. Two environmental covariates were used: the latitude of the site, and the type of production (green or white asparagus). It is shown in this paper that most of main effects and genotype-environment interactions could be explained by additive and symmetrical parental influences. The pseudo-diallel structure was therefore reduced to the values of 3 parameters associated with each parent (main effect and 2 regression coefficients) and could thus be easily interpreted. The model was used to evaluate yields of all 816 possible hybrids within chosen environmental conditions.