@Barbalee, a
"reciprocal cross" is when you make the cross "both ways". You use the pollen from plant A on a flower of plant B, but then you also use the pollen from plant B on a flower of plant A.
There are a couple of reasons for doing it this way (at least in the daylily world).
One reason is related to the perception that making the cross one way (in one direction, as in parent A
must be the pod (or pollen) parent) will give you better results in terms of flower face or plant traits or whatever. (I recall reading an article (or maybe it was a short series of articles? ) by one of the more scientific people in the AHS world which seemed to pretty much debunk this perception (for the most part) as a myth, yet the belief persists. I recall one hybridizer not that long ago saying that he got better results (in terms of getting a ruffled seedling) if he used the more ruffled parent as the pollen parent.)
So the scientific evidence (from an analysis of the registration database) says that (for most of the crosses examined) it doesn't matter which way you make the cross, yet some people have had experiences (with their particular parents) which suggest otherwise. There is some scientific basis to believe that some traits
may be influenced by the maternal parent due to extra-chromsomal (not chromosomal) DNA, but which traits are those? Plant health and vigor? Budcount? Rebloom? "Base" (underlying) petal color? You see the problem... so just to be safe and cover your bases, maybe it is best to do the crosses both ways!
The other reason for doing a reciprocal cross is that sometimes, one of your intended parents balks at being a pod parent. As an example, I repeated crosses all last season between two diploid daylilies, but I could only get the cross to "take" (set a pod, produce seeds) in one direction. (I was aware of the hybridizer's comments on the pod-difficult parent, but hope springs eternal, and I had my own bias/reasons for trying to force that plant to set pods.)
There are various reasons why a plant is a reluctant pod setter. Sometimes it is something as simple as something mechanically wrong or wonky with the pistil. Sometimes the pistil is just very long (true with spiders and Unusual Forms) and that has its own issues. Other times, it is nothing obvious. (Many years ago I tried repeatedly to set pods on a certain plant; every time it looked like the pods had set and were growing nicely, and then two weeks in, they uniformly all withered and died. What was up with that?!
)
Sometimes the situation is not as extreme as absolute pod infertility. If you are persistent enough, you may manage to set a few pods, and get some number of seeds. (You will always get far fewer seeds with tetraploid daylilies than with the diploid daylilies.) It is not always clear what makes the reluctant pod parent finally set a pod for you; it could be something as simple as a sensitivity to daytime (or nighttime) temperatures, but who knows. (One hybridizer trick that I recall reading about was to either try to "self" (self-pollinate) the plant, or else set a pod on it with pollen that you don't care about, in order to get it "in the mood".
) Or maybe you just don't have the "Magic Touch". I have a few plants that the bees seem to do a much better job setting pods on than I can manage (which I admit is annoying!). It could be that on those particular plants, the ovum is only receptive in a certain time window (when the bees are active but I am not), perhaps maybe even starting late afternoon/early evening on the day before the bloom even opens (but the pistil has protruded just enough to be pollinated). Again, who knows. (Moths? Could it have been moths, not bees, who were the pollinators?
)
The opposite can occasionally also be true - the pollen, for whatever reason, is not fertile. Sometimes it is obvious just by looking at it with the naked eye (whitish pollen, in daylilies, is bad); sometimes you need to look at the pollen with a microscope (you will see lots of pollen fragments, "trash" pollen, but nothing normal sized and good).
So by doing reciprocal crosses (presuming you have the time, space, and energy to grow out the resulting seed(ling)s if the cross works both ways), you cover your bases. So long as one parent is pod fertile, and the other parent is pollen fertile, you will get seeds (and will not have wasted an entire season trying to make a cross in only one direction, a direction that simply will not work). If you grow out seeds from both directions, well, you can make up your own mind if there is any substantial difference between the resulting seedlings.
