Spinosissima hybrids, or just apomictics?

So, I made a cross last year of ‘Condoleezza’ X ‘William III’, having chosen the seed parent just because you can put most any pollen on it and get seedlings. Well, I have about 75 seedlings and about 5% of these are already showing flower buds. I’m inclined to think these are likely the result of apomixis, or should I not make that assumption? I expected all of these to be non-remontant. What do you think?

Hi Paul,

Do you see some signs of ‘William III’ influence in the prickels and foliage? That would be exciting if it is a carrier for repeat bloom genes!! There are different forms of apomixis and some forms result in an embryo being different from the parent in that meiosis occured and some gene segregation. I found that to be the likely case with DayDream being a diplospory apomict of Lavender Dream in my AFLP marker work. There is no evidence of ‘Henry Kelsey’ being the male parent, even though I trust that is the pollen Ping pollinated the bloom with.



It’s really difficult to determine hybridity at times. Either some characters are completely masked or possibly apomixis is at work.

It seems the surest way to bring back the masked characters is to grow out selfed seedlings?

I’ve begun to suspect some of my seedlings are the result of apomixis as well.

The globalsciencebooks.info website is unreachable at the moment (~2am EST) but I thought I saw mention of the subject of apomixis in one of the abstracts in the volume David just published. I would like to know more about it myself because I suspect some of my own seedlings are apomictics.

One big question I have is whether such seedlings would be clones of the mother or would they be remixes of the mother’s genes such as would be expected from deliberate self-pollenation?

I think you should just wait and see.

After all, Stanwell’s Perpetual has one of the best repeat bloom-- and where did that get its gene?

It seems to me the spinosissimas have several hidden genes that only show once they’re outbred.

Right now I’m growing a single OP seedling of a spinossima (possibly Harrison’s yellow… possibly the Double Yellow unnamed) and it has at times up to 7 leaves.

I’m impressed with 5 leaves such as the 77-361 and some of its seedlings (my seedling has 5 leaves) but a seedling that has 7 leaves seems special to me.

I don’t recall neither spinossima 7 leaves.

Of course I’ll never know its pollen parent, but it seems to me to be spinosissima as it can get.


What makes me especially suspicious is that the ones that are budding show no signs of the Spinosissima character. Clearly many of these seedlings DO, but not the ones that have juvenile remontancy. Most of the ones that are budding also appear mossy, which makes me even more suspicious they are apomictics. The ones that show clear evidence of Spinosissima hybridity are becoming very attractive l;ittle plants with beautiful foliage!


I have found that in crosses involving species and near species of many groups, you will see a lot of apomixis if you get any seedlings at all. I have tried several times to get crosses of R. sericea ptericantha and when I do get seedlings, they are all clearly the result of apomixis. Last year I got a dozen seedlings of ‘Joycie’ X ptericantha and they all bloomed as juveniles and all looked like ‘Joycie’.

The problem I’m having with some of my possible apomictics is that they don’t resemble the seed parent either. Some of these crosses are so wide one can’t know what to expect.

I remember the first time I saw ‘Lila Banks’ blossom and I immediately discounted it as a sefled seedling.It wasn’t untill Fall of that year when it started producing banksia-like foliage that I knew for sure I had a hybrid.

Had that character not shown itself, (a genetic fluke in itself), I would have tossed that seedling and that would have been the end of the story.

Now I’m shy to toss things so readily.

Good point Robert.

In making some crosses onto Golden Angel just now I observed that the outer most pistils had not only stigma on them but also that the sides of the pistils look like anthers. The presence of male gametogenic tissue on the female organ may go a long way toward explaining apomixis.

Hi Don,

That is a great question. For DayDream and Lavender Dream we followed morphological traits for comparison. We didn’t publish on that yet (maybe won’t get to it now, we were thinking of a second article). DayDream had less petal substance and some other minor things compared to LD.

Apomixis just means without mixing. So, basically just without fertilization or mixing of male and female genetics. There are different stages of meiosis that can be reached and different consequences for what genes and their copy number get passed on to the embryo. Often when we hear apomixis people think of an exact duplicate of mom. This is possible. For instance, in citrus seeds we often have multiple embryos germinate from one seed. One is typically the product of sexual fertilization and the others are from the surrounding nucellar tissue that is female tissue and just a somatic cell of mom. They fight it out and the most vigorous one(s) survive.

We can also have meiosis start. There is pairing of chromosomes and recombination is possible. Depending on how recombination occurs and segregation of those chromosomes, it will influence what the apomict will get gene wise. A 2n egg can develop into an embryo. We read about this in some of the French groups work trying to extract haploids out of 4x cut roses. Some were 2x and some were 4x. It was found that the 4x ones were 2n eggs that developed. Because of recombination, there are some regions of chromosomes that are no longer represented in the 2n gamete, and then its complement is represented twice. So, in essence we can get a little bit of inbreeding.

For instance, DayDream had ~94% of the AFLP marker bands with the primers I used as Lavender Dream. Both are triploid. A 2n egg is most likely with a little bit of recombination to lose some represented chromosome segments and then duplicate some others. In Europe they have a stipulation about Essentially Derrived Varieties in their intellectual property rights system. So for something that is an “EDV” the owner of the original also owns the “EDV”. This typically relates to sports. Our idea was to save the morphological data for the comparisons to be part of a more theoretical paper regarding “EDV”'s.

So, ultimately, depending on recombination and what genes you get recombining and changing in dosage/representation one can get variation. Typically these various forms of apomixis should lead to offspring closer to the genetics of the female parent than selfing. There are exceptions and different modes of 2n gamete formation and… that leads to exceptions. One can also call an unfertilized egg that leads to a haploid also apomixis because it does not involve “mixing” either.

It’s amazing how diverse roses and other plants are at being able to adapt and try to survive with generating viable and variable offspring.