Dear Hanna,

Sorry that your question sat here for a while unanswered.  I was not paying as much attention as I should have !

I understand what you mean.  Should we see differences when we do a “reverse cross” ?

My sense is that theoretically there should be some differences.  I’m not very knowledgeable about genetics, but since no one with more knowledge has answered, here’s my admittedly limited understanding.  Apparently each parent does not contribute an equal amount to each seedling. It’s my understanding that the pod parent contributes some genetic  “maternal DNA”, which the pollen parent does not bring along with it. So in that sense, the pod parent may contribute more to the seedling that the pollen parent does.  What qualities are carried by this extra maternal DNA, and what influence it may have on seedlings I can’t say.  And perhaps my understanding is wrong to begin with.  But I think it’s possible that crosses done in different directions, using the same parents, might be different.

How one could tell might be hard to observe though, because in my experience, if you grow out 50 seedlings of a cross, there’s naturally  quite a bit of variability. As a result, looking down a row of seedlings, one can often have a hard time trying to guess what sort of parents were involved.  Some parents (like Blushing Princess) seem to make larger plants, and plants involving Old Faithful seem to make seedlings which bloom later in the season.  So it’s likely that when crossing herbaceous varieties, you might not be able to see much difference between crosses that were made in one direction or the other.  While they could be different, natural variability might obscure whatever those differences are.

Having said that, if the genetic makeup of the two plants are quite different, it might make a difference.  As I understand, there are one or two reverse Itoh crosses, and the plants from those crosses do look different than from crosses made in the normal direction.  Crosses between complex garden varieties and wild species might also produce differing results if done in different directions.

Again, others are sure to know more about this than I do.

Bob Johnson