I'm confused: a diploid?

Rose Genetics Ploidy Level
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Questions about Wasagaming:

Reading on HMF I looked at the parentage and was hoping someone could explain for me (it would have to be at a kindergarten level)
Why Wasagaming ended up as a diploid.

Rosa Rug. Thum. diploid (so that makes sense) x Acicularis hexaploid, octoploid, or tetraploid (any of these apparantly)

This then was crossed with Gruss an Teplitz a tetraploid.

Is it just that it panned out a diploid the first time, not a triploid or tetraploid.
And then just happened to in the second cross as well?

Now, what to do with it??? I am planning on crossing it both ways, as the hips it had on it last season had no seeds in them, but it has been used as a seed parent, at least from what I found on HMF.

I have several seedlings I’m interested in crossing it with: several seedlings from Therese Bugnet, one from Martin Frobisher, also one from Lilian Austin that I’m fairly certain the pollen parent was Martin Frobisher (it is still small, but repeated multiple times its first year).

I was also considering Mary Rose with it and Lilian Austin herself.
Debated red (like Henry Kelsey or Ramblin Red) since Gruss an Teplitz put some darker color in it.

Some other way you would choose to go with it?

I would like to retain the cup shape and fragrance, hopefully adding a few more petals. Foliage can go whatever way looks wise, preferably disease resistant, obviously.

Any thoughts would be greatly appreciated. Thanks!

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This is likely to sound flippant, but I sincerely don’t wish to sound that way. This is one of the issues with sweating ploidy. You can make yourself crazy worrying about it and that isn’t going to improve your chances. Make the crosses you’re interested in making. Some will work, some won’t. Why? I dunno and likely no one else really will, either. If you’re still interested in them next year, try the ones you’re really intrigued with again, or those which failed, again and see what happens. You are going to encounter some which won’t work one year then suddenly do, and vice versa. All you can do is make educated guesses and hope they bare some similarity to what actually exists. Some of the most exciting results are those you didn’t even consider.

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Thanks for the input!
There are a lot of things I will end up trying: I was just wondering if there were some that would be more likely to be compatible, as I would start with these first. I don’t mind a long shot or even repeatedly trying to get the desired result, but for right now the more likely step would be preferable. Certainly, in the long run, I would like to test some more unlikely things, but space is an issue for the time being.
Duane

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Understood, Duane. Fortunately (or unfortunately, depending upon which side of that coin lands upward) many you make won’t take. More won’t germinate. Some are going to explode like winter rye grass. Some will set seed but will never germinate them, no matter what you do, short of excising the embryos. No matter what, you will always be short on room. It’s simply the state of Nature. Absolutely, there will be some which are more compatible but none of us has the knowledge of which they will be until you do it. Some of them won’t set seed where I am, but will where you are, and vice versa. I grew Rosarium Uetersen in the hot inland valley where it was a full pompom of petals and never had any sexual parts, therefore no hips/seeds. The color was a fry your retinas, neon, poster paint coral. I saw it at the coast and didn’t recognize it. There, it was a pastel coral pink, deeply cupped with a center full of stamen and anthers and it set hips like a weed. I’d wondered HOW anyone ever used it for breeding as where I grew it, that was an impossibility. Also there in the heat, Iceberg NEVER set hips. At the beach, it was a literal fruiting plant. Every bloom set an orange-red hip with seeds.

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Hi mntlover,

I agree with Kim that it is better to try whatever cross that you are interested in than trying to decide whether the cross is possible. There are many variables that can influence whether or not a cross “takes” and produces viable seeds.

That being said, do you have a type of rose that you would like to breed? What kind of seedlings would you like to develop? There may be some parents that RHA members could suggest to you that would be more likely to lead you to your goals.

Jim Sproul

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The Gruss an Teplitz parentage seems dubious for Wasagaming.

Also for Yatkan, which is listed as possibly Gruss an Teplitz x La MĂ©lusine (a rugosa hybrid) on HMF.

It is curious how you could get an extremely cane hardy rose with that cross. And also a diploid, if Gruss an Teplitz is a confirmed tetraploid.

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I had wondered how such a cold hardy plant would come from that cross.

I started trying to cross Rugosas with English roses. Other than Rugosas the only cold hardy plants I had were Party Hardy (which set no hips & not sure of pollen yet, as I made a cold hardy mix of pollens) and William Baffin.

Since then I have decided to try other routes than Rugosa (last season was Above and Beyond and Ramblin Red). Also working towards Kordes instead of Austin roses looking for health. But same desired goal: old style roses that are more cold hardy. Also fragrance is really important to me.

I am continuing Rugosa work a bit because I have seedlings from Therese Bugnet, Martin Frobisher, and Hansa. Then I saw Wasagaming in a nursery and pick it up, mainly because of bloom shape already on a cold hardy plant.

I picked up Henry Kelsey at the same nursery. Should have grabbed Louis Jolliet at the same time. I had a hip of seeds from it and they have germinated really well.

I have what I believe are Rosa Woodsi seeds germinating. Also seeds from a species I picked hips from up in the Cascade Mountains, one just germinated. Thinking of Rosa Carolina as a possibility also, but wanting to wait until settled and have property to plant out more plants on.

Any thoughts of what you would do to attain this goal?
Thanks for all the input!
Duane

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I should add that I have seeds germinated from other Rugosas I got hips from over the summer. A blush, maybe snow owl?
Frau Dagmar Harstrup, Jens Munk, and Will Alderman. Looking for any with juvenile remontancy. I have two seedlings with juvenile remontancy already, one from Therese Bugnet and one from Martin Frobisher. I was hoping to have more to work with, maybe crossing each of these together.
Duane

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Why Wasagaming ended up as a diploid.

Duane, I have wondered similarly about some roses. For instance, when researching Spin-hybrid roses, I had noticed that ‘Harrison’s Yellow’ and ‘Namdalsrosen’ are listed as triploid, in spite of their purported parents all being tetraploid.

I suppose one option is that the parentage information is incorrect, probably most likely the pollen parent being incorrectly listed.

Otherwise, one could assume some unusual genetic event. I know that some diploid roses can produce not only n=7 pollen, but also some low percentage of 2n=14 pollen. I’m less certain whether a tetraploid rose could produce not only standard (for it) n=14 pollen, but also pollen with just 7 chromosomes. In other words, some diploid roses can produce a mix of 7- and (less commonly) 14-chromosome pollen; can a tetraploid rose produce both as well, just with the 7-chromosome pollen obviously being the less common?

Anyhow, it’s an interesting question, and thanks for bringing the topic up. Perhaps someone who has a high level of knowledge re. meiosis can shed some light on this.

Matt

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R. acicularis nipponensis Crépin is a diploid. In addition, other plants have been identified as R. acicularis that are not it.

I recall a debate some years ago (maybe 20) about a rose reportedly bred from R. moyesii that was a tetraploid rather than a pentaploid as expected. The solution, I think, was that the parent species was R. fargesii, a tetraploid that is sometimes described as the darker red form of R. moyesii.

It also happens, now and again, that a supposed cross turns out to be a self-seedling of the seed parent. Van Fleet’s ‘Silver Moon’ is an example.

The ‘Harison’s Yellow’ business is troubling. I have also read that ‘Persian Yellow’ is triploid. The diploid Pimpinellifoliae species usually have smaller chromosomes than species in other sections of the genus. “DNA amounts of tetraploids were disproportionately larger than those of diploids which suggests that they originated as hybrids with species of sections with larger DNA amounts.” Yokoya, et al. Nuclear DNA Amounts in Roses (2000)
http://bulbnrose.x10.mx/Roses/breeding/YokoyaDNA2000.html

When the chromosome number is inferred (flow cytometry) rather than actually counted (eye ball and microscope), a tetraploid might seem to be a triploid if the different in chromosome size is not taken into account.

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Thanks Karl! That is very interesting, esp. as I have a few Spin hybrids of my own. Although how far away do we get and still consider it a hybrid of a Spin.? I know there was discussion about that with Rugosas.
Interesting it could be a tretaploid instead of a triploid if smaller size was not taken into account. Does the smaller size have any effect (negative) on things as the genes shake out in the crosses?
Thanks!
Duane

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Duane,
Are Rosa spinosissima and R. pimpinellifolia the same? If not, which is the Scotch rose?

Sabine (1822) wrote that R. pimpinellifolia is the small-leaved Scotch rose. Therefore R. spinosissima is the larger-leaved, alpine species.

Hurst, on the other hand, reversed the names.

Names aside, one species should have glandular acicles (bristles with a tiny drop of goo on the tip); the other should have short straight woolly styles. Look for these traits, along with the numerous small leaflets.

Some traits, or groups of traits, can be passed along together. So long as they persist, and distinguish your plants from “common” garden roses, I guess you could call them Hybrid 
 whatevers. No matter what I might think, people will go on calling certain roses “Rugosas” so long as they inherit the rugose leaves. Austin found that

When Griffith Buck’s Rosa laxa Retz. hybrids were backcrossed to typical HTs and Floribundas, the offspring segregated as Hybrid Laxas and not-Laxas in about equal numbers. David Austin similarly found that ‘Conrad Ferdinand Meyer’, crossed with other garden roses, produced Hybrid Rugosas and not-Rugosas.

I expect that hybrid of Spin. and Pimp. will behave similarly for some traits, though the pattern may not be so tidy because these are tetraploids presumably derived from different diploid ancestors.
Karl

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I had to dig through my notes to get some info on chromosome size. This is a complicated subject with contradictory indications.

Ewald (1996) reported that his cyclamen hybrids carried large chromosomes from one parent species, small from the other. This appears to be the case in Rosa, since the tetraploid Pimpinellifoliae species are clearly not mere “doublings” of the diploid species because the total mass of the chromosomes is disproportionately large.

As for paring of small chromosomes with large, I think the restriction will involve more factors than mere size. In another thread I wrote about “Promiscuous DNA” , genes that can jump from nucleus to mitochondria, from chloroplast to nucleus, and so on.
http://rosebreeders.org/forum/viewtopic.php?f=2&t=56434#p70864

Even if the smaller Pimpinellifoliae chromosomes don’t pair with those of “garden roses”, there is the possibility of jumping. As an example, The dwarf bearded Irises frequently show the “Pumila spot” on their falls. When these tetraploid dwarfs (x=8) are crossed with the diploid or tetraploid (x=12) tall bearded types, the spot is missing. The chromosomes from the two parents tend to stick to their own kinds 
 8 pairs from the dwarf parent, 12 pairs from the tall. These are fertile, but the “genes for spot” do not segregate out as quickly as one might hope. I can t find the note, but as I recall, only one out of nearly 800 seedlings will show the spot. Once you have it, though, it is easy enough to maintain and intensify the spots.


http://bulbnrose.x10.mx/Heredity/BiradarMaizeHetero1993.html
Biradar & Rayburn: Heterosis and nuclear DNA content in maize (1993)

http://bulbnrose.x10.mx/Maize/McMurphyCornSomes1992.html
McMurphy & Rayburn: Chromosome and Cell Size in Maize (1992)

http://bulbnrose.x10.mx/Heredity/EwaldCyclamen1996.html
Ewald: Cyclamen hybrids (1996)

http://bulbnrose.x10.mx/Heredity/Darlington/DarlingtonChromoSize.html
Darlington: Chromosome Size (1958)

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Although this discussion deals with Irises, it applies equally Roses.

The World of Irises (1978)
Chapter 26
Iris Genetics
Kenneth K. Kidd

ALLOTETRAPLOID FERTILITY

Fertility and genetic behavior of allotetraploids is even more complex in hybrids containing both homologous and homeologous (“almost identical”) chromosomes. During meiosis of such hybrids, some cells will have the normal pairing of two chromosomes, others the association of three chromosomes of a set of four, and still others the association of all four similar chromosomes as in an autotetraploid. Because of the random occurrence of each type of pairing, it would be impossible to predict what segregation ratios might result. Conversely, studying observed ratios might be largely uninformative. This pessimistic conclusion specifically applies to the modern tall bearded hybrids.

Heinig and Randolph (1963) studied the meiotic behavior of tetraploid iris species and tall bearded varieties. Their observations indicate that for many and possibly most chromosomes tetrasomic pairing can occur, even among the technically allotetraploid cultivars. However, in any one variety not all chromosomes showed such pairing and the number that formed quadrivalents varied among the cultivars studied. Nevertheless, enough homology exists among the n=12 genomes to allow occasional allosynapsis (the pairing of chromosomes from different species). Thus, in tall bearded hybridizing it is possible that any allele can eventually be recovered as a tetraploid homozygote with four doses.

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Possibly. Depends on if the cause of the juvenile remontancy is the same/similar
although it’s more a case of not having delayed remontancy or once blooming genes right I think. I mean look at the sports of once blooming climbers, the dwarf sports rebloom (ie, Little White Pet, Baby Faurax) as do their seedlings that arent climbers.

Im attempting similar (juvenile remotancy in rugosa hybrids) with Calocarpa (rugosa x china) which produces a lot of seed, should see some results in the next few months. If the rugosa x chinas (ie Sydney, Bonvista) that Svedja bred were here Id be using those too. They may not be as cold hardy as you need though.

It is positive news for another TB seedling, as i have her and should probably throw juvenile remontancy pollen at her to see if anything happens. Now to order Martin F

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let me know how things go for you. It will be interesting to compare notes at each generation. I have seedlings up from three different rugosa hybrids right now, we’ll see if I get any that bloom this season.
Duane

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Also, thank you Karl for all that info! Gives me much to consider.
Duane