more on climbers

Google Scholar is no help. what is the relationship between a non reblooming and a reblooming climber. -if there is one. I can grow Rosa multiflora but but the winter winds do the prunning not me. Is it are nonrebloomers are plants that grow long canes? and how does it express with the RoKSNcopia and/or RoKSN LTR genes.Johannes

What is the relationship beween non rebloomers and reblooming climber. Are they two different alleles same genes? or are non rebloomer climbers roses ones that simply grow very long canes because of other gene locus. what does this all come down to is if you cross (RoKSN WT climber X RoKSN copia) self. Would a small number be reblooming and climbing. (I dont think they will).

What is the difference between Tea roses and Tea-Noisettes?

Cross Rosa multiflora with a Tea rose. The F1 generation seedlings will be once-blooming ramblers.

In the second generation, you will find plants much like the F1, along with some Dwarf Polyanthas. There may also be some “long legged” Polyanthas that are taller than dwarfs, but not climbers. ‘Mme. Levavasseur’ can’t quite make up its mind: some canes are short, others keep growing another foot or so before blooming.

Cross R. multiflora with Rosa moschata or a Noisette, and the F2 generation should give you some more Noisettes, as well as once-blooming ramblers.

Finally, cross a Tea with certain Tea-Noisettes and you may get an assortment of Teas and Tea-Noisettes. E.g Virginia (Tea) was raised from Safrano (Tea) x Marechal Niel (Noisette).

The rebloom of the China roses is different from the continuous bloom of Noisettes. Noisettes like ‘Marechal Niel’ may carry the China-gene, while expressing the Musk trait.

Hélène Maréchal [Rosa helenae Rehder & E.H.Wilson x Maréchal Niel] suggests that the Moschata bloom habit may sometimes appear in the F1 … assuming that the published ancestry is accurate.

Is this at all helpful?

Ack! Karl! Those F1 seedling from the Synstyllae are just a tease! LOL
How common is that though, honestly? Does it make more sense to view such as an inheritable trait, or as a genetic flaw/mutation in the normal suppression of rebloom, and hence a one-off, not to be aspired to?

This is a complex question where not all of the answers are known, and one could write an essay on it.

First, I personally believe, there are different genetics for different types of climbing growth. This is a personal belief with no academic support. Not that there would be any since its of low priority research. For example, I do not believe the Caninae types and Rosa wichurana are responsible for the same type of self-pruning. Mentioning Rosa wichurana brings to one study on the closest topic, and they found there may be “a linkage between plant form and flowering behaviour.” As we do know, repeat flowering is a plastic trait modified by environment, as well as other plant genetic factors. We also know there are variances in rate of repeat within the chinensis type, as well as in relation to other traits, like fragrance. Lots of factors in play.

I bring up many of these factors, because they can also create variance in the rate of repeat in repeating climbers. So the relationship is a tangled web of factors on that merit alone.

Here is one limited study done that comes close to the topic: Heritability of Plant Architecture in Diploid Roses (Rosa spp.). Search for it online.

Another study concluded: “By screening this database for candidate genes involved in the flowering process, we identified 13 genes potentially involved in gibberellic acid signalling, photoperiod pathways, and floral development. Based on expression data, we put forward different hypotheses on the control of flowering in rose (photoperiod control and involvement of gibberellins) relative to what is already known in Arabidopsis.”

There are continuous orthologs, genetic linkage, multiple acting trait loci, and so on. I don’t think there is currently a way to answer that self-pruning and continuous-flowering are definitely or definitely not always linked. Especially at this point in time in terms of academic publication presented.

I’m not sure what you mean by “self pruning”. Maybe it’s something like this:

It is very useful to understand the growth habit of the plant’s ancestors when considering how rebloom will behave. The Teas and Chinas are descended from climbers. If a terminal growth is removed, one or more buds lower on the cane will break and continue the upwards growth. But when this growth habit is combined with the everblooming trait of Teas and Chinas, each shoot eventually terminates in one or more blooms. This is equivalent to cutting off the shoot, and one or more buds will begin growing … and eventually give rise to another inflorescence.

Now, imagine a Gallica in growth. IF you cut off a terminal growth, other buds may start into growth, but will not have the vigor seen in climbers. If they do produce blooms, they won’t be impressive. For this sort of growth, it may be best to treat the plants like Hybrid Perpetuals. When they bloom, cut back to the stool, forcing the plant to push up more canes that bloom at the top.

Rebloomers, as I call them, produce new flowering shoots on wood that has already bloomed. Don’t cut the shoots back to the main cane. Scot (1939) below, discusses this. I had a ‘Paul’s Scarlet Climber’ that bloomed at least five times in one year on these “spurs”.

Repeat blooming from a lateral that flowered earlier in the season.

Scott: How Remontant Climbers Act (1939)
Brownell: Everblooming Climbers (1944)
Hamblin: Reblooming Ramblers (1944)
Hamblin: Everblooming Climbers (1945)
Hamblin: Yellow Climbing Roses (1960)

Self-pruning is a catchall term for plants that terminate un-ending growth (ie climbing, trailing in roses) to bloom/fruit on a new basal if the possibility (perennial recurrence for roses) exists in that growing season. Many plants have a unique term for similar concepts. The catchall originated from tomatoes, iirc.

The genetic concept implies that something specific in the plant is halting or interrupting un-ending growth rather than the concept that something very specific is signaling it to climb.

It seems that although RoKSN is a very key gene in the flowering pathway, there are other genes that govern flowering to moderate expression. There are roses like ‘Marie Pavie’ that bloom in cycles, others that are more continuous, etc. It was interesting to see the allele combinations for some of the antique roses that repeat some in the recent paper from the French team. I look forward to ordering the primers and trying to characterize some roses for RoKSN alleles. I suspect the RoKSN LTR and A181 alleles and the other minor genes that modulate expression are key in some of the repeat blooming climbers. I think R. setigera would be great to study more. It is one of the latest bloomers and may have a delayed/extended suppression of likely RoKSN G181 to allow floral initiation later into spring. Hybrids with polyanthas give some nice ramblers with a very extended period of bloom I think due to the potential for later flower initiation into the season before the functional RoKSN product accumulates enough to suppress initiation.

David, have ever studied the rebloomer Rosa beggeriana? am unsure if I have the right one. It too is late blooming in large clusters amd continues right though into fall. if anyone asked me is would have said it looks like a F2 of (Rosa rugosa xR.pisocarpa). The flowers are not significant in size or colour (white) so have no garden value. In my climate tho it has a lot to offer especially when the only real alternative is R. rugosa.

Hi Johannes,

Great idea! I have a plant Paul Olsen shared with me to do some chromosome counts on years ago. It was diploid, like anticipated. I just planted it at my new place and got it out of the pot again. Hopefully in its new spot it can thrive. I don’t remember this clone being too free in flowering, but maybe in the good spot it is in now it will be happier and display that trait.

We got it from the same source. Just talked to him yesterday.

I get lost with Beggeriana and its synonyms.
Atchison (1881) described R. anserinaefolia (Crepin, non Boiss.) as briar-scented. Does this agree with yours?

You may already know this one, any info would be useful. One picture attributed to a Loubert on helpmefind - not much info - want the color

Rosa beggeriana nigrescens

Only seen it offered once and twice have tried to import - unavailable.

Have the Finn hybrid. White Star of Finland. Once bloomer, white small bloom, near micro seed compared to normal sized. Apple scent? I have no recollection as try to avoid touching it due to nasty needle like thorns.

Should add Wikipedia quote … one of my xyz Stanroses good for my garden

“Rosa beggeriana is a species of rose found in Anatolia, Iran, Afghanistan, Pakistan, all of Central Asia, Xinjiang and Gansu in China, and Mongolia.[2] It is a winter‑hardy rambler, with typically flat white (rarely light pink) flowers, and small red (becoming black‑purple) hips.[3][4].”

“Its ‘Polstjärnan’ (polestar) cultivar (of uncertain parentage) is the cold‑hardiest known climbing rose” (White Rose of Finland).

Riku I must have an incorrectly labeled seedling from DBG. I still like it. It is not as hardy as Rosa woodsii but reblooms well and is more disease resistant. And much of it’s progeny is fertile.

Hi Johannes

You have an interesting rose that repeats and sounds like a nearly full hardy repeater.

One of the interesting observations Margit makes in HMF is the Rosa beggeriana hybrid Polstjärnan (White Star of Finland) hip shape is significantly different from the globular hips of posted photos of Rosa beggeriana - though color and size seem about same.

What color and shape do the hips look like on your repeater?

Hip form, size and color comparisons makes me muse - without facts, tech or science, if Wasserman used R. pendulina on a R. beggeriana. Grow R. pendulina and, as in Finland, completely hardy.

Hello Rick, The hips are round, stay red, persistent sepals. They look like a small Rosa woodsii.

Thanks know what hip picture you mean as grow Rosa woodsii “Kimberley” …

The more I read about R. beggeriana and its alleged synonyms, the more confused I become. Schrenk was very clear that his R. beggeriana was a Synstyle.

And Rosa Silverhielmii Schrenk, another supposed synonym, is allied with R. Cinnamomea, according to Boissier (1888).

Then there is Rosa cabulica. The specimen Hurst knew by that name must have been more closely allied with the diploid Spinosissimae species. I really need to find more pictures of this crowd.