I finally had bloom this year on several of the half dozen or so hybrid seedlings from Rosa bracteata X (rugosa X palustris). I felt lucky to have gotten them at all but expected them to be highly sterile. If at all possible, I figured that rugosa pollen would have the best chance of producing a hip. So, I pollinated quite a few blooms. All of these aborted. But later in the summer, I noticed that one hip was forming down low on the plant, where I hadn’t done any pollinating. Upon examination, I found two more hips. All three hips are on laterals coming from the same side of one cane, spaced about six inches from the next. I thought that it looked possible that a sector of that cane had possibly doubled chromosome number (spontaneously). However, I can’t see any difference in appearance. It’s also possible that a bee figured out a better pollen to use on those three flowers.
I had held off on discussing these hips, thinking that they could be empty or contain only aborted seeds. But, today I harvested the first rusty-red hip and found nine seeds inside. They were smaller than I was expecting (and surrounded by hollow space and aborted seeds; so I tried the sink/float test (even though they’ve got one quarter palustris ancestry and so possibly floating viable seeds). Of the nine, five sunk and four floated. I can hardly wait to see if any will germinate.
I figure it’s time to sink this posting… so, in case anybody wondered about the other two hips… four seeds in one and two seeds in the other.
So in the end I’ve got fifteen seeds (8 of which are sinkers in the water test) – wish me luck in germinating them.
Congratulations on the hips and good luck with the seeds! Please let us know how they germinate. This year I have about 17 hips from the pollen of a possibly doubled Mermaid on tetraploid seed parents, and about 14 hips from the pollen of a possibly doubled Little Mermaid on tetraploid seed parents. I also have 6 hips on the possibly doubled Little Mermaid from tetraploid pollen. I’ve never had any success with Mermaid before, so I’m very excited about the hips, as you must be about yours. I wonder what I’ll do if I get a lot of Mermaid-sized seedlings, but that would be a good problem to have.
Am I remembering right that Mermaid is normally a diploid? … if so, then your possible doubled version would be tetraploid (or amphidiploid). I think that it would be a very useful breeder even if (or especially if) it throws a lot of Mermaid-sized seedlings. My bracteata seedlings are pretty rangy growers. But, I’d rather see that than a bunch of runty ones. I think plant size reduction could be accomplished in relatively few generations – look at the minis that come from minis X large roses.
I am especially interested in seeing what you get, using the possibly doubled Mermaid as the seed parent.
By the way, I was wondering about the origin of your possibly doubled Mermaid and Little Mermaid. I’m guessing that they weren’t just naturally occurring. I hope you don’t mind me asking, but did you use doubling treatments to obtain them. I would fully understand if you want to keep some information to yourself for now, so don’t feel obligated in any way to “tip your hand.”
Thanks for the good wishes and for sharing your good news of success.
Good luck germinating.
Yes, Mermaid is normally diploid. I treated Mermaid, Little Mermaid, and eight other diploids with pressurized nitrous oxide as discussed in this thread[/url]. I’m planning on writing an article about it for the RHA Newsletter.