Actually, prickleless would be great - why not?
Thanks Jadae, Help me find roses didn’t list a US supplier for Bukavu. Where did you get yours? Do you know if it is a diploid or not?
Mark, I have thought about using blanda hybrids also. It might make more sense to build upon someone elses work, and not start over from scratch.
I’ve only seen Lilian Gibson once years ago at the U of M Arboretum. If I remember right, it was a large shrub that was a once bloomer. Theresa Bugnet has a lot of good qualities, but it is fairly disease prone. Probably about the same as rosa blanda.
I posted a link to an article about triploid roses, where the fertility of them can run from abundant hips to none at all. Fertility is not a good indicator of ploidy as there are are many reasons for infertility.
The plants I have flowered for the first time this year. Two of them only produced a few flowers (4 or 5). One produced more like 10 or 12. This one looks the most like rosa arkansana and could possibly be a mislabled rosa arkansana. Or it could mean it is a hybrid and the arkansana genes are dominant over the blanda genes. As far as I can tell, all of the flowers have produced hips and they are turning red already.
I live in east central Minnesota about 40 miles west of Minneapolis. The only two species I’ve seen growing around here are rosa blanda and rosa arkansana. The mother plant looks like a typical blanda and does not appear to be a hybrid.
Thanks Stefan, I’ve seen that key before and if you look close, rosa woodsii is listed twice. Once under “stems unarmed, bristly at the base” and under “stems bristly to top”. Rosa blanda is also listed twice, once as rosa blanda var. hispida.
So that tells us that there is quit a bit of variation in phenotypes. And there is such large ranges in the descriptions that anything could fit them. It is really hard to get a complete and accurate description in just a few sentances.
Paul, I’m going out on a limb and say that your a lumper and not a splitter. Botanist or zooligist either want to miniize the number species and say there is just much variation in the species(lumper) or they want take any variation and call it a new species (splitter). You fit into the latter. I beleive as you do that there is much variation within species. Just by looking at the species plants around me there is so much variation in height, thornyness, disease resistance, flower color, flower size and on and on.
But I also beleive that species eventually diverge, and that it possible for natural hybrids to occur especially if they closely related, humans didn’t invent hybrids. It happens in birds all the time.
The Baltimore Oriole and Bullocks Oriole were origonaly thought to be two seperate species. Then they found hybrids of the two. So they thought the two species must be one but with two different distint populations. Until they realized that the two groups molt at different times of the year and any hybrids of the two were really confused. So now they are back to being two seperate species.
I also want to point out that you are counterdicting yourself. Earlier in this thread you stated that there is no rosa blanda on the northern plains as the botanists claim but it is actually rosa woodsii. Now you are predicting that it will be proven that they will be one and the same. They can’t be different and be the same at the same time.
Crossing a diploid with rosa acicularis to create a tetraploid is fine if you are trying to get rosa acicularis genes into a breeding program. Because 3/4 of the genes will come rosa acicularis. But what if you are trying to get the diploids genes into the breeding program? How do you create a tetraploid with the majority of the genes coming from the diploid? Perhaps by creating triploids and crossing them with similar tripliods.
Regarding my comments about Rosa blanda not being a species on the northern Great Plains, I didn’t contradict myself. You say, “They can’t be different…” I never said or inferred that in any of my statements. I only said Rosa blanda and Rosa woodsii are likely the same species. Obviously I have to make reference to Rosa blanda as an accepted species to argue that it is not on the northern Great Plains.
I’ll let David Z. respond to your last paragraph. He knows genetics much better than I do.
Paul, I must have misunderstood what you were saying. As a new commer in the association I certainly don’t want to be putting
words in your mouth. I feel that your comments have been very helpful and informative. And I look forward to your comments in the future.
I wouldn’t go with triploid x triploid crosses unless you had very fertile triploids (which does happen!) and could count the chromosomes of your offspring (because you could work yourself back down to the diploid level that way, too). Paul’s idea of creating a tetraploid that contains 1/4 genes from a diploid is really excellent for your purposes as long as that tetraploid is also reasonably fertile. Apparently it still hasn’t been done much since I’ve never heard whether fertility is good from such a cross, but it is promising. It’s also possible or even likely that the traits you value in your woodsii/blanda/both/neither/whatever are also present in R. acicularis. That is, if you can get ahold of the real thing.
You could also create one good triploid that has the characteristics from your diploid that you wish to promote, and then cross that to other tetraploids and simply select the ones that inherited the traits you want. After all, it isn’t necessarily about the quantity or ratio of genes, but rather their quality. Of course, if you’re working with traits that tend to be recessive, it would require some way of building up the numbers of genes through backcrossing, sibling crosses, chromosome doubling, etc.
And David can still respond since he’ll have more interesting things to say anyway 
If I’m not mistaken, the Hybrid Teas and the Floribudas both started out as tripoids. And like you say, they were crossed back to the tretraploids and probably to each other to create tretraploid offspring. I was thinking that if one did create ferile triploids, then one might be as succesful in incorporating the diploid genes into a tetraploid as the early breeders were with them.
I used to think why would I want create a triploid, but other than creaing a tetraploid as Paul Olsen advocates it is really the only way to get the genes from a diploid into a tetraploid breeding program. And it has worked in the past. So why not.
I beleive Paul has been successful in crossing a diploid with R.acicularis along with a few other RHA members. I don’t know how fertile these crosses have been. If the first generation isn’t very fertile I would think that sucessive genreations would more ferile.
I have about 20 seedlings of what I think are R.acicularis. I originally had the intent of crossing them a diploid, but they aren’t very healthy and they aren’t very vigorous(less than 2 feet tall). So far they haven’t shown me much to get exited about. So I don’t know if I’ll pursue that route or not.
I’ve been thinking lately it might better to work with existing hybrids that already have some of the features I’m looking for, than to start over from scratch with the species. Because you’re already one or two steps closer to your goal right of the bat. Plants like Theresa Bugnet or Metis might be a better place to start with.
Of course, I would be glad if David had comments to add.
I did some quick math. Using Mendel’s laws and assuming a perfect world. If we assume two sets of chromosomes are in the gamates, then a triploid should pass on the gene from the diploid two out of three times. If you cross this with another triploid, say a sibling, then the ratio for the offspring should be as follows. 1/9 without the diplod gene,
4/9 with one copy and 4/9 with two copies.
If you cross the triploid back to the tetraploid parent then the ratio breaks down as follows. 1/3 without the diploid gene and 2/3 with one copy. If you then cross two plants with one copy(siblings), the ratios comes out as, 1/4 without the diploid gene, 1/2 with one copy and 1/4 with two copies.
As you can see, crossing triploids will give you a higher percentage of plants with two copies after one generation than back crossing to the tetraploid parent after two generations. Now because of ferility issues the actual number of offspring you create by back crossing to the tetraploid may be higher. But the higher percentage with two copies from the triploid by triploid cross in a shorter time span makes it worth looking into. What the heck this is all for fun any way.
If the the trait you are trying to incorporate has complete dominance, then one copy of the gene should be able to exert its influence over the other three copies. If on the other hand it has only partial or incomplete dominance then you should only see limited or partial expression of this trait. And if it is recessive, then like you say, you will have to do additional crosses to bring that trait out.