This also means that plants with the desired combinations of
genes can be pre-selected before extensive and expensive
field testing. In many cases, the objective would be just to avoid advanced testing of a number of lines with similar genotypic constitutions. Current limitations to
the application of breeding by design or similar
approaches include the prohibitive cost, since thousands
of marker loci need to be scored in breeding material
and, perhaps more importantly, our current knowledge
and understanding of the function of the majority of
agronomically important genes and allelic interactions
with respect to phenotype which remain unknown.
Therefore, at least in the short term, such approaches
will probably not have a great impact on crop
improvement