Looking through the google literature, I find that both tulips and lilies were treated much as I suggested to make diploid pollen, used with tetraploids as egg source in case of lilies. Nitrous oxide is preferred in grasses because colchicine induces polyploid leaves the block growth of the apical meristem. With sorghum, the entire plant shortly after fertilization is put in the treatment chamber for a day, or so. The chamber was a pipe 6 " diameter and 8 ft long. The idea is to let the chromosomes double without the cell dividing at an early stage of embryogenesis. Optimally it only happens once, making just one doubling. Hence the importance of time. The high pressure is to give a high concentration of this pretty insoluble gas in the water of the fertilized cell. Seems that maybe time is not for diffusion but for rates of cell division.
Some tubeless tires are 10x3x4" and smaller and a light probably could be installed for extended time. Good point about decompression, undoubtedly important at 2-3-4 atmospheres. Also on the water treated seeds maybe the added pressure would force water though the seam of the achenes. Conversely a vacuum on the water treated seeds may aid. Probably the best way would be to weld up a container with a portal for observation. Is it worth it? Since there are three really good plants here that set hips but fail to germinate seed and maybe with N2O a person could get two for one and end up with something weird. This is probably more involved than just slapping something together.
Hi!
This is very interesting stuff. …
I also found a nice paper with good illustrations too, you can get it as a pdf on the site:
In zea mays experiments they used 600-1000 kPa, so thats abt. 6 to 10 atm; the best results they got for 10 atm!
So pressure unfortunately seems to be really necessary. …
Hmn.
Grx!
Arno
So here we do have the range:
600 kPa - 1000 kPa is abt. 6 to 10 atm and abt. 90 - 150 psi.
Here’s a converter. 
I built this nitrous oxide pressure treatment apparatus in 2003. The main components are a professional painter’s pressure tank and an automotive nitrous oxide tank. I bought both of them relatively inexpensively on eBay.
I treated a half dozen roses with this apparatus, including the one gallon Blanc Double de Coubert in the photo. I typically used 90 to 100 psi for 36 to 48 hours. The treated roses were all ones that had been completely infertile in my garden. Some of them showed no effects from the treatment. A couple that had never set OP hips began setting a few OP hips (Blanc Double de Coubert and Little Mermaid), but the few seedlings I got from them died young. I also got a few seedlings using the pollen from a treated Mermaid. I had previously made many attempts with pollen from an untreated Mermaid and never got a hip.
Hi Jim!
This looks perfect! 
I got an Idea now, perhaps a watertank could be manipulated for that use … .
But perhaps you should only overthink your strategy which roses you take and try it again with your great setting.
If you take good taking diploid seed parents of interest and good pollen partnes of interest in a crossing (e.g. rugosa x polyantha - or as jadae said in the other thread, noisette roses) then the doubling of chromosomes should be happen with your possibilities here.
Or good taking diploid seed parents x Mermaid / etc. … .
Also that should give better response.
What I mean is: Perhaps you only wanted too much in one step!
Grx!
Arno
lol, I love it. Only for the rose of roses haha. My favorite part is the rose sitting in between both objects as if to think, “Oh crap. Im next. Sup … fellas? =/”
I recall this idea btw. It seems like so long ago. Knowing what I know now, I would definitely skip on Mermaid and BDdC. I actualy tried them both as well. I am somewhere glad they failed for me because I really dont want any tea hybrids. I am actually kind of puzzled no one has tried something like Hrug x poly-tea or HRug x poly-noisette. I think that would lend more favorably to rugosas. I bought Maria Bugnet but I dont think I will get that far next year. It will probably only be big enough to try MB x microminis next year. I would love to try something like Jens Munk x Perle d’Or/Leonie Lamesch/Trier/Cecile Brunner/La Marne etc etc etc though. I think Jens Munk x Trier would be ideal. I grew Blanc Double de Coubert for like… 15 years? I loved it but it had two traits I loathed. First, it hates even being tip pruned. That made winter shaping a delicate art. I always knew to expect some branches to die way down or completely off. Second, it grew like a rocket straight up. It was otherwise an awesome plant.
I think if I wanted to give a go with Mermaid, I would use Prima or Many Happy Returns. However, after growing Climbing Pearl Drift, I have no desire to grow a Mermaid descendant again. I have not actually seen any potential in anything from that line, which was disappointing at each discovery.
So, yeah, I think I learned that my desire to use something was stronger than the actual potential of the goal. There are always new possibilities in life. But I am still intrigued with chromosome doubling. I would love to see it used on something like Trier, lol. Sometimes I am more curious as to how going from diploid to tetraploid (or reverse) changes the whole being of something. Once one minutia of something changes, the whole can change.
er rose of roses = love of roses. typo 
Oh jadae, “rose of roses” fits too. I laughed and laughed minimum 5 minutes about the description of the thoughts of the rose in the middle, veery funny. …
I also tried a lot of crosses with Mermaid in 2002-2004, nothing was good in this direction, I remeber one excessively done was Rosa nitida x Mermaid.
And thats what I wanted to bring back in mind, although Mermaid seems a road to nowhere.
Instead of rugosa the nitida or rugotida direction should be perhaps better to get more ornamental fragmented plants of a good shape.
Hazel de Rougetel / Corylus here spreads via roots in all directions. next year a quarter of the garden will be dominated by one plant comming up there and there … .
So, ok: Why not taking use of such plants, together with your noisette or Perle d’Or ideas. …
Next year I will try to go that direction with corylus, only problem, I will have to collect pollen now, because Corylus always flowers really early with its strong first flush.
OK. Already noted.
Grx!
Arno
Again to the foto: i am missing an “L” in there:
Devilbliss
@jadae
Rosa rugotida ‘Corylus’ x Rosa multiflora ‘nana’
would that not just be cool?
And than further the F1 syblings crosses, - packed in a 7x pressured N2O Atmosphere (only
no, better of course, at the first step: already the Corylus plants will have to be put into the cage a few days after being pollinated; then the F1 is perhaps already fertile by polyploidy.
The good thing is: one should see it - perhaps one can even measure it in comparing the F1 plants - as the leafs of the tetraploids will be significantly broader and perhaps even darker green.
Also the stomata will express differently.
There will be a range in the F1 as ‘nana’ is a hybrid as it seems, but the tetraploid will significantly fall out of that range, i am sure.
In glossing threw the pat.ap. above, was someone trying to make flying pigs. Chicken wings wouldn’t cut it, Argentavis Magnificens was possibly available in our life time. So embryos and stalks, but they all do not transform to repetitive DNA. I’m glad Jim Turner with his great set up gave it a shot. Maybe a low pressure clear plastic cylinder and focused noble gas beams via magnets to polarize and promote growth. More than spooky.
Spooky is only that some chemicals like colchicine work even better against animals than against plants. … I have tried that stuff (with a lot of respect) for doubling chromosomes in Rosa persica but I think now i could sleep much better beneath a pressure tank full of 6-8 atm N2O than beneath a 100 mg package of colchicine.
So thats it, and its ok, pigs on the wing.
Geesh, y’all, I can see the headlines now…
“Amateur Rose Hybridizer Dies Happy: Killed in freakish laughing gas accident”
As I began reading this thread, I wondered to myself, “Interesting, but will anyone actually undertake this craziness?”
Leave it to this group.
Jim, that’s awesome. (Even if it hasn’t worked yet…) “Love of Roses” indeed. Poor plants… ‘Love’ hurts sometimes, no?
…But should you get a tetraploid banksia, I’m first in line for a cutting!
Just playing devil’s advocate here (darn you guys for putting this bee in my bonnet!): Clearly cells must be in active reproduction for this to work, and I gather from what I read that most of the successful research in the poacea (grasses) involved freshly pollinated plants. I don’t understand enough to grasp the process (Is the goal to mess with the first mitotic division of the dploid embryo?) but targeting a specific stage in development might help efficacy.
I wonder if, seed-division aside, Jim’s dark tank would reduce the amount of active growth occuring, and thus reduce the chances of success? Would light help? (But I reckon a heavyweight acrylic dome would not be cheap, and mounting of valves to acrylic could result in dangerous stress fractures.)
Pressure and time of exposure varied tremendously in various experiments.
(I just did a quick perusal of results from Googling “chromosome doubling nitrous oxide”)
I imagine timing would be beneficial, yeah.
Hi Philip!
So the question could be: Who wants to switch the light on in a tank full of N2?
No, just kidding; I don’t really think that embryonic development will be totally different in light situation. The development of mersitems of living plants might be different - but even that I would not believe to be a knock out factor (indeed it might be a knock out factor against my knowledge and believes, here).
I think the embryo will have its cell divisions even if its dark. There is no immediately necessary fotosytnhesis for the growing embryo and its first divisions. Only hormones, biochemical setting, water and temprature should be the most limiting factors.
So, you are right with the other guesses, I think, the moments after the first divisions are the interesting ones for N2O treatment. The earlier in development, the better the outcome, as tetraploid cells will divide not so fast compared to diploid ones. In most cases you will get a mosaik plant. So the aim has to be: groiwing and then propagating desired parts via rootstock or cuttings, - to purify the best outcomes before getting washed out by strong diploid growth.
Grx!
Arno
N2 should be N2O in the above posting.
… and mersitems are meristems … ok sorry for posting too fast.