Interesting that Wich. is supposedly very self infertile, Simon. Virtually every flower formed hips and, though I’ve not germinated any, they obviously were fertile, viable seed. I’ve permitted the BTW to throw itself through a very large, escaped Manetti root stock which has grown from under a Lili Marleen.
Yep… it’s interesting though I seem to remember David also explaining how selfing barriers could be broken down by certain climatic conditions like high temperatures. Not having read the full article I don’t know how, when or where the observations were made or whether in your location these selfing barriers might also be compromised. I just found it interesting. I tend to think that at times the planets can align in magical ways to cause even the most barren of cultivars to show a whisper of fertility… when the mood suits them cue the Barry White. Regardless of whether it is a cross or not, it seems at least a little certain that if thornlessness is determined by a single gene that the OP seedlings will be carrying at least one copy. It should therefore be reasonable to expect that it could be brought back out again by selfing,sibling crosses, outcrossing to something else thornless… or back to BTW… I mean… I don’t even know whether BTW is actually by a hybrid itself of garden origin and so not even have these selfing barriers.
Simon,
Thanks for your input and for reposting David’s listing… I had forgotten so many of the details. I remember on a poultry forum that certain “reference” articles are collected under one permanent heading which always appears and are “locked”. David’s list would be a perfect example of it so that we all could refer to it as needed. And David could amend it as new research developed.
Jim P
Good Morning Everyone!
We’ve been working for years with the understanding that ‘thornlessness’ is a recessive trait.
I can’t say that I remember reading any articles on it…it’s just something that’s rumbled around in my head for years. (That means I probably read it somewhere, and I just can’t remember when/where I found that info.)
Someone asked how Dr. Basye came up with the thornless version wich. It’s my understanding that he just germinated a bunch of R. wich OP seeds and selected the one with no thorns.
It’s interesting that most of you say that your R. wich do not self, ours (Dr. Basye’s version) does. You never see hips our on plants because we must cut it back, or it will take over the field!
Here’s an article references on ‘ thornlessness’:
Debener T (1999) Genetic analysis of horticulturally important characters in diploid roses. Gartenbauwissenschaft 64:14–20
I’m hoping the BTW seedling here is a self 
Hi Nat!!
Thanks for answering my question further up, I was actually hoping you were gonna say that Dr Basye got his BTW by planting OP seed from a usual type R.wichurana and selected out a thornless version…what a coincidence!! …I was about to sow OP seed from my regular R. wichurana to see if any of the OP babes turned out to be naturally thornless…there ya go!!!
Now my R.wichurana (little monster…it has occasional thorns not too many actually), is going to be put to some good use after all…other than to see if it makes good rootstock! He he he he.
I have no seed off it from this season as it was severely chopped back, but I’ll let it set the OP hips next season. The nursery lady that sold it to me claimed that its original source clone (mine is a cuttting from that original) sets loads of tiny red OP hips with seed, which the local birdies love to devour.
When I bought my R.wichurana about 6 months ago, it had one tiny reddish-orange OP hip left on it, the rest had been eaten up by critters (it was late spring). Inside was one seed, but I killed it trying to embryo culture it … Duuughhhh!!!
:O)
Sorry to revive an old thread, but now that the plants have grown out a bit, I was wondering whether there’s been clear evidence of selfing or not. While that report did say 0% selfing, Semeniuk’s paper on inheritance of wichurana rebloom Inheritance of recurrent blooming in Rosa wichuraiana | Journal of Heredity | Oxford Academic was about selfing wichurana, then doing sib crosses of the selfings. He reported high germination rates and mentioned no difficulties. It would be great to know which (if either) category BTW fell into.