Hybridizers: It can be fun to breed your own zinnias - Part 4, 1 by Zen_Man

Zen_Man wrote:
Corey,

It's very likely the Oklahoma Mix from Harris doesn't have better stems than the Oklahomas from Hazzards. As I recall, Hazzards also has Oklahoma Mix. It's possible that both Harris and Hazzard's get their Oklahoma Mix seeds from the same wholesale seed grower.

"I guess that as soon as a bloom opens, it is susceptible to bee and wind mediated pollination?"

It is susceptible to pollination as soon as the stigmas are exposed.

"I would have to strip a branch of ALL open flowers, and net it over, to get unpollinated blooms? But unopened buds could be left in place as "virgin" blooms?"

I don't think you need to be that careful. The honeybees, bumblebees, carpenter bees, and such (yellow jackets aren't interested in zinnias) are only interested in the pollen and the nectar in the pollen florets, and don't care about the stigmas. A zinnia that is just presenting receptive stigmas isn't interesting to them, and doesn't really need a protective net as long as it isn't producing pollen of its own. Some zinnias produce very few or no pollen bearing florets, and they are good "natural" females, because you don't have to go to the trouble of "emasculating" them for cross pollination. Incidentally, zinnia pollen is too heavy for wind pollination. I believe gravity does carry some pollen spilled from the florets down onto the stigmas below to "self" them.

Nearly all zinnias are heterozygous to a certain extent, even the so-called purified strains. So recombination comes into the play in the creation of both the pollen grains and the egg cells in the seed ovaries. So the act of "selfing" a zinnia is actually fertilizing a recombinant egg cell with a recombinant pollen grain. The so-called selfed seed is actually an F1 hybrid between the two "virtual" zinnias that produced the pollen grain and the egg cell. I use the word "virtual" because we never actually see those two zinnias -- only the result of their F1 hybrid.

If you make crosses between Oklahoma, Benary's, Gem, and Cut-and-Come-Again, and you think of those four strains as the corners of a square, you have six lines connecting four points, which means six possible inter-strain crosses, or if you take into account the direction of the crosses, then there could be twelve different male-to-female and female-to-male inter-strain cross pollinations. And that's not taking into account the complexity of the different colors. You have the opportunity to make a lot of different cross pollinations using that stock of seeds.

I usually skip the formality of netting my female breeder zinnias, and just pollinate them and put a coded label on them, for later guidance when I save the seeds. I takes only a few minutes to pollinate a zinnia. As the flower develops to add more stigmas, I return to pollinate them as well.

The actual pollination isn't much more time consuming than attaching the labels, assigning ID codes, and making journal entries about them in my notebook. There a lot of ways you can attach labels to a future seedhead. I have settled on light green velcro tape written on with an Ultra Fine Black Sharpie marker. It's easy to attach, windproof and weatherproof.

This is a recent "marigold flowered" zinnia specimen.

ZM