Hi Highlander,

In response to the question in the title of your message, "What will 2nd generation zinnias look like?", the answer would be, assuming that the first generation was pollinated by bees, that the 2nd generation will look somewhat similar to the 1st generation but with some zinnias that are different.

"If pollen came from a red flower and pollinated that purple-pink flower, will those seeds be a cross between red and purple-pink? "

There is some semantics here. If you took pollen from a red zinnia and used it to pollinate a purple-pink zinnia, you would say that you crossed the two zinnias. People would say that you "made a cross between red and purple-pink". So, in that context, the answer to your question would be "Yes", pollen went from one zinnia to another, so a cross was made.

But there is a very real complication to the event. Zinnias are normally bee pollinated and bees visit many zinnias merely to gather nectar for honey, and the pollinations that they do are completely accidental. Which implies randomness. So, in your example of the red zinnia and the purple-pink zinnia, unless they came from a carefully controlled laboratory experiment, they were randomly pollinated by bees and both zinnias are heterozygous. Meaning that they are not pure strains.

So each pollen grain from each zinnia contains a random recombination of genes from the male parent. And we have no idea what that recombination might be, because some of the DNA codes could have come from the recessives. The same thing with the egg cells -- their DNA is a random recombination of the female parent's DNA codes, some dominant and some recessive. The genetics of the egg cells differs from the female parent and the genetics of the pollen cells differs from the male parent. Both the pollen cell and the egg cell represent "virtual" zinnias that can differ significantly from the zinnias that we see, and their union represents an F1 hybrid between two such virtual zinnias. The F2 generation will contain many recombinations of both seen traits and unseen traits.

Since commercial zinnia seeds are bee-pollinated, a packet of field grown zinnias will contain some F1 hybrids, courtesy of the bees, so both your red zinnia and your purple-pink zinnia could be F1 hybrids between unknown parents. Not only can you not predict with certainty what their cross would produce, you also cannot predict with certainty what selfed seeds from them will produce.

To make a long story short, zinnias are full of surprises.

ZM

What would I expect

==>> the short answer... is you have no expectations .. so you just have fun observing what comes of it all ...

ken