I’ve created a number of hybrids utilizing ‘Prairie Harvest’, primarily as seed parent.
Fascinating to learn it’s triploid.
I was looking at the few healthy hybrids I made and did not cull of Prairie Harvest x Cape Diamond today.
All appear to be non-remontant.
What amazes me is that Ive never seen any reference where Kordes guesstimates the unknown half of Kordesii. I cant think of many hybridizers, even on the commercial level, that can’t even help themselves not to. They must have some idea.
Michael,
I don’t believe there is “another half” to ‘Kordesii’; it is believed to be as follows:
In an article in The Rosebank Letter, #33 Sept 15 2000 Dr. Felicitas Svejda reports:
R. kordesii originated from unreduced gametes of the usually sterile R. rugosa x R. wichurana ‘Max Graf’.
I have always believed this to be a fact.
But early on in this thread, David also stated:
the evidence of a semi-double to double bloom of Rosa x kordesii is very strong, overwhelming evidence that it is not a self<<<<
Maybe this statement has prompted some conjecture about “other half” for ‘R.kordesii’.?
Kordesii produces a small percentage of repeat flowering seedlings when used with another fully remontant parent.
I’m also inclined to believe it’s a chance OP hybrid rather than a self.
In his book Roses Kordes wrote:
“In 1940 I succeeded in obtaining from a self-pollination of R. rugosa x wichuraiana hybrid Max Graf a rose which combines the hardiness of R. rugosa with the large, full flowers of our garden roses. This cross was eventually named R. kordesii Wulff and it has been proved to be a very fertile parent.”
He goes on to say “it is an auto-polyploid, since there are 28 chromosomes.”
So, unreduced 2n from Max Graf + normal tetraploid pollen?
I am sure that the unknown half contains some derivitive of multiflora. Kordesii, Dortmund and Rosarium Utersen all have the same cluster formation (no matter what size or flower count)thta the Grootendorsts have. They all have that odd side branch within the clusters, which I have only seen on roses descending from Rosa multiflora and its kin. My best guess is that the unknown tetraploid, if it is assumed that Kordesii is not the product of a doubling effect, is something similar to Eva, Johannes Boettner or Hamburg. Also, I have an extremely difficult time thinking that something like Aurora or Raymond Chenault came from a autoploidy/selfling in its 2nd generation. The colors are very modern and extremely saturated.
Second guessing Wilhelm Kordes is risky business. He says he ‘succeeded’ which implies he tried, he says it was a selfling and he refers to it as ‘this cross’.
There is actually more uncertainty about Max Graf than about kordesii. I started writing an article about Max Graf, hopefully I’ll have time to get it done for the next newsletter.
I’d love to read it when you finish. It sounds fascinating.
I look forward to your article on
David,
I whole-heartedly agree with your idea of running genetic markers on Max Graf. I hope you have the chance to do it at some point.
Debener has the makings of a marker library with his chromosome mapping project, and I know other folks like David Byrne are contributing to it as well. Someday we may not have to make educated guesses on ancestries - but I have to admit that’s part of the fun.
I don’t want to oversell my article, it was intended as a little companion piece to another one I have been working on so it’s really just a human interest thing. Max Graf originated here in Connecticut and I’m hoping to get some information together that can flesh out the story a little bit.
Don
Hi David.
All this stuff you are sharing is totally awsome!
Ok… Since I failed in finding trifluralin it was suggested to me that I try and find some autumn crocus to exploit the naturally occuring colchicine in these plants. I picked up half a dozen large bulbs yesterday (and I have to say I am a bit worred about their toxicity… will take every measure to ensure my safety but am still a little nervous about it). The plan is to try laevigata first and if I can get this to work maybe longicuspis var sinowilsonii, bracteata, multiflora, gigantea, and when clinophylla are large enough maybe I’ll try it too. I have wichurana species cuttings plants on their way so it might be interesting to try these as well. I’m not going to try this until spring as I figure periods of active growth are more likely to result in success than now when everythng is dormant (or at least slowed down). To prevent this thread from becoming too long I think I’ll start blogging it instead (see link… nothing on there about it yet… might take some photos of the Autumn Crocus bulbs tonight… some of the info I’ve found about them are a bit scary!!!).
Simon check out if you have a product called Preen it has trifluralin in it.
Preen??? The only Preen I know of here is a stain remover?
David, I’ve got a mental block on something… trying to get my head around the manner in which colchicine and other mitosis blockers function and how the resulting cells are different from normally produced cells.
I’m not seeing this properly… During prophase, under normal conditions, when the chromosomes duplicate themselves they then line up along the equator and spindles attach to the centromere and pull the chromosomes apart towards opposite poles in preparation for cytokinesis… ok I get that but these mitosis blockers work by inhibiting the growth of the spindles don’t they? If these microtubules don’t form how do the chromosomes migrate into one cell at cytokinsis and then, if they did manage to all get in the one cell, do the doubled chromosomes remain attached at the centromere??? If so how does that affect future mitosis? Is that why they experience reduced vigour? Is it all a bit random? Sorry if this is getting too specific… I’m just trying to make sense of this for myself more than anything.
Simon, if you have the spare change hanging around you might like Genes IX. There is a Genes X coming out next year but IX is the last edition actually authored by Ben Lewin. Even the previous two or three editions would suffice and can be had much less expensively.
When I did a basic search online for trifluralin it seems that it is available in Australia or at least at one time. You might try a farm or ag. supply store. Preen the weed killer however has not been tested in Australia. I am not sure however if you can get trifluralin in Australia even if it is available it depends on your laws. You may need a special license to buy it.
Simon, Preen is a product similar to Casaron in its usage. They are both used to prevent seed germination in mature beds. Here is the label:
Hi Simon,
That’s a great question. There are things unknown about the function of the herbicides and colchicine. They both supposedly effect microtubule function. Colchicine is much more active in animal microtubules than plant microtubules, so it is especially toxic to animals and is used in higher concentrations on plants to get the job done.
As the chromosomes are being pulled from the metaphase plate and the duplicated sister chromatids are being separated, the spindle fibers and their microtubules are disrupted. The cell is arrested and at this point the sister chromatids are separated, so the chromosome number is doubled. If the cell survives and lives to divide again normally, it starts with twice as many chromosomes. There is a lot of variability as not every cell is at the same stage when the treatment is applied. One needs to wait and see what grows out of the growing point and overtakes the other kinds of cells to get growth that is stable. I have gotten a triploid from the process and aneuploids from probably chromosome breakage/loss/etc. From that triploid, the seedling had a diploid root sucker so that was telling that the seedling starting out was diploid.
It would sure be great if you can get some treflan. Preen is just treflan sprayed over a carrier of ground up corn cobs if I understand correctly. You would have so much more control in mixing a known concentration. If you can find surflan that is the formulation that solubilzes oryzalin, another common herbicide that also is used for preemergent weed control.
Sincerely,
David