The four hybrids I moved out to our new house a couple of years ago are maturing nicely now and are currently in full bloom. I put an overall habit picture and bloom close-up of each here: bracteata hybrids
Here’s a link to see Rosa palustris and the first F2 to bloom from the bracteata hybrids:
Nice roses Tom, I like the white, could you tell me from the inception of the original cross how long it has taken you to achieve the outcome(flowering F2) please.
Very interesting flowers on those complex hybrids. If only they’d repeat bloom.
I have observed very strong linkage disequilibrium with the offspring of Carefree Copper in various combinations, both ways. Very hard to get blending inheritance of appearance along with repeat blooming. With Rainbow K.O. as pollen donor a number of plants- the repeaters- are much more like RKO than CC. But the non-repeaters are like CC.
I put pollen of David Z’s R pomifera on a number of things and they either look like selfs, or like pomifera. One dwarf/mini on a hybrid of [Carefree Beauty x Rise N Shine] took 2 seasons to get big enough to bloom. It had two ephemeral flowers this year. I went to work early that day and missed them. The foliage is pomifera. The hips are even more fuzzy that the parent pomifera, and larger. Note it is fertile with a tetraploid parent on one side. It bloomed somewhat later than the R pomifera parent, which might be a location effect but I don’t think so.
Thanks David and Larry!
It took me a a few years longer for all this because I haven’t always been diligent in taking proper care of the rose seedlings. The bracteata X (rugosa x palustris) didn’t really start setting the occassional open-pollinated hips until probably their third growing season. The seedling from that, has taken about 3 or four years to get to flowering size. So I’d say that from that idea (and first pollen daubing on bracteata) to second generation could take as little as 5 or 6 years - that’s assuming you had the F1 rugosa X palustris already on hand, which otherwise would add at least 3 more years (one for the seeds to mature and two to get to flowering size).
So starting with the three species all ready to flower, if all seedlings were treated great and flowered in their second or third year, this should theoretically be do-able in around maybe 8 years. In actuality, it’s taken me 25 years. But in my defense, I really didn’t start out with the idea, but rather stumbled and fumbled my way along until it just sort of happened. I started with the cross of rugosa X palustris way back in 1988. That was actually my very first rose cross. The bracteata cross was probably done sometime around 1995-2000, and the open-pollinated hips that grew this final seedling were collected and planted maybe 2009. In those intervening years, I was busy making lots of other crosses and having lots of fun!
Very nice hybrids, Tom. An interesting mix of traits from those rather disparate lines!
I have to say the BH-4 plant catches my eye. I’m not usually a big fan of near-species white roses, but can’t help but think that one has some interesting potential.
(Ya really gotta start throwing some repeaters into your mixes! LOL)
Tom,presuming you will continue with this line of rose,what might you cross it with to give repeating form if this is what you are after.
Good question!
I’ve had two leanings lately… first that I should try minis to restrain the rampant growth habit and hopefully get rebloom also.
But since so many of the flowers abort and the few that mature have only 1 - 4 seeds, that strategy might be pretty difficult. I’m hoping one of the next generation seedlings (like that one I probably shouldn’t have called an F2) will be more fertile.
But that relatively extreme infertility has suggested another strategy to me lately. I’ve seen it stated that “the more sterile a diploid hybrid, the more fertile will be its tetraploid version”. So it occurred to me that a tetraploid version of one of these rampant almost sterile hybrids would probably be a little stubbier/compact and also much more fertile. Still might take a few generations to get rebloomers but I think more of the good character of these hybrids might be preserved using this strategy.
All just conjecture at this point.
Thomas, we’re to have high nineties to low triple digits here for the next week, so I collected all the anthers available from Pink Petticoat, Tom Thumb and Golden Horizon this morning with you and this post in mind, in case you would be interested in any (or all) of them. They’ll easily fit in a First Class envelope and will be ready for mailing tomorrow. All I’ll need is your address if you’d like them.
These are some impressive roses. You certainly have patience that most of us would love to have.
One thought. Are you planning to cross this with your rugosa x glauca. I think that would be interesting.
Thanks again! I don’t know if I’d call it patience - maybe it’s more just pig-headedness. lol
And Larry, I’ve been thinking the very same thought about needing to get rebloomers into more of my plans. But actually I’d hoped originally that the reported rebloom of bracteata would combine with the rebloom genes of rugosa in some of these seedlings and give me repeat. Doesn’t look like it works that way, but it’s been a fun line anyway.
And for all the mixed messages the assorted genes could be giving, these four are pretty robust and healthy. I’d hate to lose that in future generations.
Adam, that’s an interesting idea. I’d tried straight rugosa pollen on it years ago, but all the flowers aborted. Now that I see how few open pollinated hips mature, and how sparse the seeds are, I think I’d be a little more determined and pollinate as many as I could - hoping to catch a good ovule. Some glauca influence, sure wouldn’t hurt the cold hardiness any would it.
It would definitely add cold hardiness. If you were truly lucky enough you might be able to get big white flowers with dark foliage. With a double dose of rugosa maybe it would rebloom.
I think the bracteata hybrids were finishing up blooming before we went on vacation in mid-July, but the third one (I’ve garden named BH3) has made at least five recent off season flowers. For such a big bush, five flowers is pretty sparse, but it’s five more than any of its siblings have made. It’s the beginning of September now.
…bracteata hybrid BH3 this morning…
Tom, have you tried crosses with other bracteata close hybrids?
linkage disequilibrium… both ways. Very hard to get blending inheritance…
Larry, this caught my eye because I’ve been under the impression that, in close species crosses, the disequlibrium is always skewed toward the species parent. I’m deliberating about some seedlings with virginiana paternity that look not at all like virginiana yet, based on the extreme care I took making the crosses, ought to be true hybrids.
Do you know of any papers or review articles that cover linkage disequilibrium?
A working strategy in order to recuperate fertility and rebloom is using (not so) low sterility hybrid pollen on fertile compatible species or close species.
A few backcrosses are often needed as species less desirable features dominate.
I.e. rugosa x (bracteata x rugosa) seedlings so much rugosa like that I thought they were selfed.
Hi Don,
No I haven’t actually tried crossing them with much of anything. The first year they bloomed I tried rugosa pollen on a few blooms and they all dropped off so I got discouraged and put my focus on other hybrids. Then having to move them, and the plain old busy-ness of life has kept me from doing more with these. Now that I know that they DO evidently make at least a few viable ovules, I’ll have to try a more determined approach and pollinate every bloom in sight. I could try the reverse as Pierre suggests (using the hybrid’s pollen) but I think I’d like to try to keep the bracteata cytoplasm if I can.
Another idea I’ve been kicking around lately is that it would be super-cool if I could get one of these hybrids to double chromosome count by way of trifluralin treatment. [I’ve had some near successes in the past with this] That would theoretically give me a 28 chromosome version that would hopefully be relatively much more fertile - since the rule of thumb is that the more sterile an interspecific hybrid is the more fertile its doubled version will be. And hopefully this “tetraploid/amphidiploid/” sort of hybrid would then also interbreed well with the modern HT and Floribunda crowd.
Tom
At the risk of boring folks, here are a few more open blooms on BH3 from Sunday evening.