phenotype bb. So if we where given two parents
that displayed golden bud but where BOTH
heterozygous for that trait Bb, we would also
produce offspring that have silver bud. But
since Bb is dominant in both parents, neither
of the parents would display the phenotype for
silver bud.This is really what breeding is all about.
When we have a strain that we want to keep, how
do we know that the parts we want to keep will
actually be kept in our breeding process?
This is where the test cross comes in. If
we create seeds from a strain that we bought in
a seed-bank how can we be sure that the
offspring will have the character that we like?
Well the facts are this. If the trait(s) we
wish to continue are Homozygous Dominant (BB)
in both the parent plants then there is no way
we can produce a recessive genotype for that
trait in the offspring. We already explained
this in the previous section.Let’s prove this:Look! It is impossible for the recessive trait(^) B B
B BB BB
B BB BB