For a historic perspective, and a lot of comparitive information, there’s a paper in the Journal of the Royal Horticultural Society, 1933, p344-371, based on a MSc. The author is Jessie Ferguson, the title “A Botanical Study of Rose Stocks.”
This is a must read if you are going to look into going with canina, laxa or any of the stocks used up to the 1930s.
My copy is a xerox from our ag library.
Use www.worldcat.org to find the library closest to you that has the Journal on its shelves.
Jim, no I have not yet tried the pressure cooker method as I was able to get enough possible tetraploid plants to keep me busy for awhile.
Specifically, Dave Zelsak provided me with tetraploid forms of R. palustris, and Flora McIvor. He also provide a first generation cross (R. palustris X John Cabot). Randy Hudges provided (Calocarpa X Nutkana) and Basye’s amphidiploid. I was able to obtain what I feel is probably a tetraploid form of Sir Thomas Lipton and R. Acicularis plus ((Delicata X OP) X (( Therese Bugnet X OP) X OP) ) and ((Delicata X OP) X Will Alderman).
My previous work with these is given at:
Http://home.neo.rr.com/kuska/2004_and_2005_very%20good%20seedlings.htm
I am now collecting this season’s hips. I have a number of hips from my amphidiploid crosses, a few from the (Calocarpa X Nutkana) crosses, and a number from the acicularis crosses.
Unfortunately, the acicularis X R-15 cross which gave yellow flowers did not set any hips.
http://www.rosehybridizers.org/forum/message.php?topid=4547#7880
One of my (Sir Thomas Lipton X Simon Fraser) plants has set hips. Another one also flowered (6-30-2006, 6-17-2006, 7-17-2006, and 7-18-2006) but no hips were formed. The (Sir Thomas Lipton X Heritage) plant has not yet flowered.
I should add that I will not know if the yellow (acicularis X R-15) pollen “took” on any other mother until I finish collecting the hips - same for the pollen of the other suspected tetraploids which bloomed (I am probably 1/2 to 2/3 through collecting now).
I hope it does :)I dont care what color mine turns out. I like the plant itself so far. If it makes a poor seed parent, I dunno what I will cross it with. I was hoping I could do (Rosa acicularis x R-15) x (New Year x Baby Love). One of the NYxBL is fully double pumpkin orange where any traces of cyanidin or peonin have been supressed. The other is a single in the color of Fruhlinsmorgen. They are dwarves with well-branched habit so I thought they would be perfect with your cross.