Back to the genetics of Color in Roses

Okay, well, now that things are growing once again (and life has settled down a bit…), I’d like to get back to a project I was hoping to start a couple of years ago. I’d like to get some firm data in place for sorting out the exact heritability of color in roses. Why? Good question that. Apart from that I’m fascinated by color, I wish I knew why!

To do this so, I need some help, so…

The first thing I need, and I am quite unable to find it, is a diagram, or photo, or drawing, or whatever, of a section through a rose petal. I’ve tried to make sections myself but apart from a quite decent binocular microscope, I just don’t have the other necessaries to make the petal preparation to look at in the first place. I figure someone, somewhere, must have already done this. So if any of you know where I can find such a thing, I’d really appreciate a link.

What I need apart from that is all the data I can get. What colors were the roses you bred and what color seedlings resulted?

There are a couple of problems with this. One is that the regular ARS colors are … not quite good enough for this purpose. Instead, what I’ve done is get Prismacolor pencils and/or Crayola crayons (ah, a new box of crayons! Still delights me after all these years!) and match the colors to those. Both are commonly available and of uniform color everywhere you go.

The second problem is that while all data is helpful, what would help the most is data on… how should I put this? … “entire litters.” I know most people plant all the seeds they get from a hip and then go on to keep only the strongest. Me, I keep them all until they flower, just to record the color/spottedness/mossiness. As important as knowing what the color results are, is knowing the proportion of colors.

So yeah, this will end up being a huge project. Will I ever get it done? No idea. But I’ll be keeping the results on the Spotted Rose Ranch website if anyone’s interested. (There’s nothing up about it now, still need to work on that page.)

As for rewards… alas I have none to give. But I will share whatever knowledge I get, and knowledge is good.

Good luck this year, everyone!


“I keep them all until they flower, just to record the color/spottedness/mossiness”

I often keep disease prone seedlings till they flower for just the same reason, in order to see what kind of variation is possible given the parentage.

Then I recycle em.

I’d like to get some firm data in place for sorting out the exact heritability of color in roses.

It is a broad net that you are casting. Do you have a specific objective?


Yup! I do the same thing. Eventually I can’t cope with the slow growers anymore!


Yeah, it is a broad net. Right now my main concern with my own roses is teasing out the genetics of spottedness; how many kinds there are and what the inheritance is. But I’m also interested in the inheritance of yellow and purple.


Fa, spotted seedlings crop up once in awhile in the general rose population. I’ve got one now that is lilac with tiny white spots.

Jim Sproul has some amazingly spotted seedlings. I think he was calling one of them “Spotted Leopard”.

Fara, you are correct about needing

When filing for a plant patent for a rose, petal color for top and reverse sides is one of the requirements. Following is an extract from a patent application help site.

“When color is a distinctive feature of the plant, the color should be positively identified in the specification by reference to a designated color atlas or dictionary. The Royal Horticulture Society Colour Chart is preferred.”

A lot more detailed in that color chart than in whatever Crayola has come up with over the years. I remember way back in school when we had a box of 8. When the 16 came out - WOW! Have no idea of what they have now!

The above info seems to ring true in my experience.