Alternate source for repeat bloom

I was wondering what approaches to repeat people are trying other than China genes?
I am considering crosses with Wasagaming. I was thinking, given Rugosa and Bourbon there are repeat genes there. Which this plant repeated a bit last year. Then I read the parentage is probably wrong.

I got some pollen from an Autumn Damask and was wondering how this repeat would combine with Wasagaming. Or better to develope seedlings from each and then cross?
Other ideas for Autumn Damask pollen?
For Wasagaming pollen?

Groups of roses I have to work with:
Canadian roses
English roses
Kordes roses
Seedlings from crossing the above
Seedlings from hybrid rugosas

Any thoughts or experiences?

Fedtschenkoana is the purported source of rebloom in the Autumn Damasks. I am not sure whence the rebloom from the nominal rugosas, which might not be pure species. Most of the others have the chinas in their origins as far as I know, but there are others here with WAY more knowledge on such topics than I have.

I imagine there are other species/species hybrids having rebloom, but to what degree I don’t know.

May I ask why you are wanting to reinvent the wheel? It seems a tough row to hoe, IMHO.

It has been mentioned that Rugosa health breaks down when combined with China genes, so I was wondering if there was another route to gain more repeat, but without the added health issues, specifically with Wasagaming. I know some have worked with Rugosas, others have worked with Damasks, still others have worked with Portland’s. Just wondering what has been discovered. My concern is that repeat will not compare to. CHINA ROUTE, which will matter especially in cold country with shorter seasons. Wasagaming bloomed a second time here at the coast last year, but had I grown it on the other side of the mountains I doubt it would have the opportunity.
Thanks for the thoughts.

One can also use, Rosa beggeriana very hardy. Was a parent of Snowdwarf. Diploid not like tetraploids

Here’s a neat paper examining that very question.

Molecular genetic studies on continuous-flowering roses that do not originate from Rosa chinensis

“Recently, a French rose group conducted KSN genotyping of a wide range of rose cultivars and found that some Damask-related roses (e.g., Damask, Moss, Hybrid musk, and Bourbon roses) and Asian roses (e.g., Hybrid rugosa and Hybrid bracteata roses) are CF but have no mutated allele of KSN from R. chinensis (Araou 2011). Because the Hybrid rugosa roses are originated from East Asian species R. rugosa, and the species has CF behavior, we hypothesize that their CF behaviors have a different genetic origin from R. chinensis.”

KSN is the floral repressor gene in roses (it’s referred to as TFL1 in other plants). This gene codes for a protein that suppresses flowering. In Rosa chinensis, KSN contains a mutation that silenced the gene and therefore the plant flowers continuously (Iwata et al. 2012). So there isn’t really a “gene for rebloom”, it’s more that there is a “null gene for flower suppression”. The paper above is stating that R. rugosa has a functional copy of the floral repressor gene KSN, yet it still manages to re-bloom.

Iwata et al. (2012) The TFL1 homologue KSN is a regulator of continuousflowering in rose and strawberry
The Plant Journal 69:116-125.

Johannes thanks. I will look up both snow dwarf and it’s ancestry. Great to learn about all possibilities.

Jwindha thank you for the link. Also for the overview of the information. Gives me the general idea while I work to comprehend the whole.

But that (overview) brought a question to mind:
If Rugosa has a functional copy, unlike China, than how is it able to repeat if it ought to be suppressing the repeat bloom?
Also, is this true of others such as Autumn Damask?

Thanks for the input!

Philip. I should have mentioned that I am pursuing the normal route. I am looking to use roses from Radler and Kordes to try to bring in disease resistance. I am also going to try back crossing to some of the healthier Old Roses I can find. Hopefully this will give me several breeding lines that I will then be able to cross between.

I should add that I am testing some newer Austin roses that have gotten fairly good reviews for health from those that grow them in various locations.
Also, I should mention Above and Beyond, as I am so impressed with it. I may already have gotten my step forward from it, the next several seasons should let me know. Thanks again for the thoughts!

Possibly another gene results in some sort of disruption to the KSN gene whether it’s an alteration to the protein or a different protein or something else, would require someone researching it to determine.

Having said that, the number of once bloomers that can bloom more than once a season here is amusing, R. Glauca can flower twice, Golden Cheronese often three (sometimes four) times, etc…so even then the once blooming genetics can be unreliable due to some factor or another. Rugosa’s (as we know them) just may be a happy accident.

Calocarpa (rugosa x china) is a once bloomer for me

Paul Barden has made posts in the past about Autumn Damask (and Portlands…rebloom mechanics would be the same) and said when crossed with modern (so china derived) that the offspring were once bloomers and wouldn’t start blooming until their second year. Also rebloom among Autumn Damasks/Portlands often didn’t result in reblooming offspring so I wouldn’t rely on Autumn Damask as it seems more like a fluke if it passes on rebloom than something with any sort of dependability.

China rebloom is likely the most dependable source and is understood the most. It may be the easier route.

The findings/interpretation of these researchers is different than Dr. Foucher’s team’s work in Angers, France. I wonder if maybe these researchers just saw that the same mutation wasn’t in R. rugosa and for some reason assumed what R. rugosa had/was “wild” type. Their paper was a number of years ago now and Dr. Foucher and his team have done more work since.

“Recently, a French rose group conducted KSN genotyping of a wide range of rose cultivars and found that some Damask-related roses (e.g., Damask, Moss, Hybrid musk, and Bourbon roses) and Asian roses (e.g., Hybrid rugosa and Hybrid bracteata roses) are CF but have no mutated allele of KSN from R. chinensis (Araou 2011).”

I’ve heard Dr. Fabrice Foucher present his work on this topic a few times and there are mutations he presented in the rose KSN gene in rugosa, multiflora, R. chinensis, etc. and he compared them and I think expression levels as well. He sequenced the gene in many rose groups and cultivars- rugosa, multflora, chinensis, bourbon, damask, etc. and presented a really nice paper of rose cultivars in France over a century or so and how over time more and more of the newer cultivars switched towards the R. chinensis allele with stronger repeat/continuous bloom. There appears to be a retrotransposon that has landed in the gene to reduce or totally hinder expression. Some alleles have different amounts/sections of the retrotransposon in it. Depending on where this additional DNA landed, how large it is and specific sequence, etc. it can totally inhibit the expression of KSN or reduce it enough to get some stray repeat like in the Damasks and their relatives that inherited the same mutated version of KSN, which is likely the R. fed. allele from my understanding. I should see if Fabrice would be interested in some of the more free flowering R. arkansana to test that species as well.

With continuous/repeat flowering being due in large part to a lack of functional KSN and it being recessive (just one functional copy of KSN seems to compensate fine and lead to one time bloom as we cross repeat blooming roses with one time blooming species), it is interesting to see that when we cross repeat flowering rugosas and polyanthas, rugosas and modern roses with R. chinensis backgrounds, etc. we do get hybrids that repeat bloom, suggesting that when the different alleles are brought together there still is dysfunctional/lack of enough effectively expressed KSN.

I suspect roses like R. rugosa, R. fed., R. arkansana as species where this has been selected in nature and is prominent across the species, they have some secondary genes that govern the expression of repeat/continuous flowering, generally preventing it, to contribute to survival (i.e. juvenile bloom would put a plant at a disadvantage before it is established). For R. chinensis and R. multiflora, it seems like the repeat bloom in these backgrounds is a more recent event out of the wild (i.e. R. odorata, R. gigantea, and R. multiflora) and plants have been perpetuated by horticulturists over the centuries without the selection for those seedlings to have secondary genes to suppress repeat bloom in the juvenile stage or awkwards times in the growing season to bloom and realistically make seeds. If they put too much energy in repeat bloom at a young age or all of the growing season,their neighbors can more easily out compete them in nature. The R. multiflora allele from my understanding from Fabrice is found in some of the early completely multiflora based polyanthas. Again, as they are crossed with R. chinensis background roses, we tend to get strong rebloomers. The alleles of different backgrounds have different regions of the gene that are disrupted helping identify the source of the gene, but ultimately functional KSN synthesis is reduced/doesn’t occur. When we cross rugosas with modern roses, we often get greatly delayed expression of free flowering, as is with many of the Explorer roses, but that may be more so these secondary alleles that are in place out of R. rugosa to help the plants carve out a space in nature first to survive before blooming freely.

I suspect there have been many events of transpons messing up the KSN gene across rose species. In order to be expressed, the alleles need to be homozygous recessive and that takes some time for alleles to accumulate and then a limited number of individuals expressing rebloom. When there are individuals that do repeat bloom, I suspect in many situations those plants have a hard time competing. It is especially interesting to see how in R. rugosa, for instance, that a mutated KSN (if we trust Fabrice correctly determined its KSN is mutated) has led to a number of associated alterations for it to be successful/a benefit in the species. R. rugosa can ripen its fruit much more quickly than many other roses (so some of the later flowers can actually lead to ripe fruit) and young seedlings typically have delayed expression of repeat bloom, etc.

It would be fun to sequence the KSN alleles in Above and BeyondTM. It is tetraploid and its mom is a mini that likely has the R. chinensis alleles and contributed 2 copies and its dad is a hybrid of R. virginiana and R. laxa. The R. laxa parent likely has an allele similar to, if not the same as, R. fed. which leads to a little KSN expression from my understanding at times and a bit more stray rebloom versus continuous rebloom. A&B blooms on new wood from the base later in summer and from some side branches if conditions are favorable in mid summer, but then is able to shut down before winter comes and is very hardy. Perhaps if we were able to catalog the different alleles out there and someone would be willing to sequence and check different cultivars or wild collected roses breeders are interested in using, we could use that information more strategically breeding for repeat blooming/continuous flowering roses bringing in different genetic backgrounds and having a clearer understanding of what phenotypes we could expect.

Perhaps that would be too much work, and researchers would prefer to focus on mutating the KSN gene through CRSPR through targeted mutation to really mess up the KSN gene to get no expression and get continuously flowering roses out of any genetic background. That process would probably lead to someone getting a utility patent and prevent us from working with those roses for continued breeding for a couple decades…

Plazbo, thanks for the input.
David, thanks for the new info and for your thoughts.
As I reread it today it brought an answer, sort of, to something I was wondering about, how we get at least some plants that repeat bloom when crossing Rugosa with China, although not most? Also, there is the delayed remontancy.
So, if I am understanding, the best and surest way to repeated/continuous bloom is through China genetics? Crossing China with others can sometimes produce some with repeat.
So, how important is genetic diversity? If repeat was the only concern I could cross China with China, selecting the most prolific bloomers. But I have other considerations: cold hardy, healthy, preferably cutting down on delayed remontancy, fragrance ,etc.
Is there benefit in crossing other genes in, especially that have the ability to repeat in some form? Are the genes (however it all works) useful in adding/layering together? Or is that redundancy not necessary and a waste of time? Especially considering there are cold hardy, fairly healthy shrubs that already have repeat bloom available to work with?
Thanks for all the input.

Thank you for your generous entry, David. It is amazingly informative. I’ll need to go over it a few times, but I am already excited about the breeding possibilities you describe.

Part of that is going to be down to which Rugosa is used, many of the Rugosa’s we currently use are known hybrids so you have to question if the crosses with china’s rebloom because of the rugosa parentage or the other parentage. Looking at Svedja’s earlier crosses (Sydney, Bonavista, Elmira, Moncton)

Sydney = Old Blush x Dagmar Hastrup, no mention of rebloom (if it did rebloom, I’d assume it’d be mentioned).
Bonavista = Schneezwerg x Nemesis, mentions rebloom.
Moncton = Scheezwerg x China, mentions rebloom.
Elmira = Schneezwerg x China, no mention of rebloom.

Schneezwerg = half rugosa and half beggeriana or laxa as the other theory goes, either way the other parent is a species with some capacity to rebloom (although maybe not in all clones of the species)…so did Bonavista and Moncton pick up the relevant genes from the rugosa side or the other? unknown.

On a tangent, when you look at rugosa that have reportedly had juvenile blooming offspring (granted not the same thing necessarily) you hit similar issues of unknown parents in the rugosa or the rugosa has an assumed parent but at the time period the rugosa was bred that assumed parent was commonly misidentified.

There’s a bunch of info but not a lot of conclusive info, there’s probably others that have far more experience in this sort of area with rugosa…I’m still attempting to crack juvenile bloom rugosa to reduce time/space requirements before getting too involved with them. As soon as I have one (with either pollen or seed fertility) I’ll hopefully be able to backcrosss to more pure rugosa and then sibling cross to recover juvenile blooming in the f2 while increasing the rugosa traits I’m looking for.

Judging from the familiar rose books, that supposedly give the unvarnished truth of rose history, we might suppose that a mutant Damask came along. It then sported again and again to give a couple of color variants.

But when I got to studying old nursery catalogs, I found that there was a good deal more to the story. Back in 1835, Thomas Willats of London listed Chinas, Noisettes and the ‘Lisle de Bourbon’. In addition, he had the following reblooming varieties of other origins. Even granting that there are sports in this list, that’s a lot of “flukes”

Blush Monthly
Crimson Perpetual
Flesh-coloured 4 seasons
Pompone 4 Seasons
Grand Perpetual
Four seasons almost thornless
Four Seasons, var. Monthly
Grand Perpetual
French Rose de quatre Saison
English Rose de quatre Saison
Red Monthly
Blush Monthly
White Monthly
Striped Monthly

Perpetual Scotch
Lee’s Perpetual Blush [Stanwell?]

I can attest that miniature X Gloire des Rosomanes produces all once-flowering large plants.

a tangential aside:

Prairie Joy, which reblooms but doesn’t produce a high percentage of reblooming seedlings, has produced two seedlings that really shouldn’t rebloom but seem to.

One is PJ x my local native rose, and the other is PJ x (R. carolina x R. centifolia).

So could Prairie Joy have some sort of gene that can overrule a dominant non-repeating gene?

What about the repeat flowering R. palustris? Is it’s repeat flowering character a random hybrid with a China or a mutation for rebloom?

Such things happen, apparently just to remind us of how little we really understand. But if the old records are correct, ‘Gloire des Rosomanes’ was seed parent of 'the reblooming ‘Géant des Batailles’, and maternal grandmother of ‘General Jacqueminot’.

It would be nice to know what, exactly, GdR is. Parentage unknown, and experts have disagreed.

Nabonnand (mentioned by Dupeyrat in 1926): “According to him, it is an error to class ‘Gloire des Rosomanes’ among the Bengals. It has no Bengal characteristics, neither in the form of flower, foliage, nor the peculiar perfume which it transmitted to ‘Bardou Job’ and ‘Comte Bobrinksy’ only.”

Walter Easley (1919) : “… Gloire des Rosomanes, a Rose often grouped with the Bourbons, but I cannot help thinking it has much of the China blood in it.”

I thought I had another comment from a grower thought it was pure bengal, but can’t find it.

Other strange cases.

The Rural New-Yorker, 66(2988): 380 (May 4, 1907)
Mme. Norbert Levavasseur
Dr. W. Van Fleet
A number of cross-bred seedlings, grown from Baby Rambler, are disappointing in that none turns out to be constant-blooming, though largely pollenized with ever-blooming kinds. All came near to the Crimson Rambler type, regardless of the habit of the pollen parent, and will probably develop into tall-climbing annual bloomers. When pollen of Baby Rambler, which has the continuous flowering Gloire des Polyanthes as one parent, is used on the stigmas of annual-blooming Ramblers of Wichuraiana hybrids, very dwarf ever-blooming plants result in large proportion, and something may perhaps be done to develop a useful group, of which Baby Rambler will likely remain the type.

I don’t want to dispute the good Doctor, so I’ll only note that HelpMeFind disagrees. In fact, there’s even a Polyantha (Cori Paling) reportedly raised from Mme. Norbert Levavasseur pollinated by Tausendschon.

The Journal of Heredity. 5: 415-422 (1914)
Amateur Rose Breeding
I had occasion to cross the Polyantha Perle d’Or (Dubreuil) by the ordinary Bengal and obtained two huge Multifloras. The characters of the Bengal and the half-blood tea, of the Perle d’Or, had disappeared from the product.

Oh, and we should forget how everblooming dwarf polyanthas can sport to once-blooming climbers: ‘Mlle Cecile Brunner’ comes to mind. And that’s a special case, anyway, in that it sports frequently to the climber and to ‘Spray Cecile’. Or so I was told by someone who used to propagate it at the nursery where he worked.

I’m not surprised that Cecile Brunner sported to a once-flowering type, and that it has further sported to a continuous flowering climber. Each of those appears to be points along its continuum of mutation. Iceberg did similarly, sporting to a once-flowering climber which eventually settled down into a continuous flowering climbing mutation. Those once-flowering sports also tend to be significantly more vigorous than the repeaters, though even the repeaters can generate huge specimen where nothing limits their size.

It is useful (I think) to consider rebloom in other plants. For example,

A Guide to Bearded Irises: Cultivating the Rainbow for Beginners and Enthusiasts (2012)
Kelly D. Norris

Cyclic rebloomers (daylength dependent). These varieties complete two distinct cycles of growth — flowering and increasing — each growing season. The second cycle of growth does not require vernalization to produce flower stalks. Cyclic rebloomers typically rebloom in the fall, when shorter daylengths mirror those of spring.

Repeaters. These varieties produce additional stalks on old growth immediately following the first spring flowering cycle, typically within a few weeks to a month.

Continuous rebloomers (soil temperature dependent). Rebloom in these irises occurs whenever new rhizomes mature, throughout the growing season, often without pattern. Their remontancy correlates well with soil temperatures, not daylength.

Repeat bloom is often seen in climbing roses. A second (and maybe a third) inflorescence emerges from a bud on the same branch, but just below the previous.

W.R. Dykes, the Iris expert, noted that “… garden hybrids are much more liable to flower a second time than are the species.” This seems to be the case for other plants, such as Penstemons. The environmental “triggers” for two species may be contradictory, giving offspring that are more anxious to bloom.

In another case involving two Cestrum species, proved to be suggestive. The “day neural” species apparently carries separate genes for multiple photoperiods.

Plant Physiol. 1966 January; 41(1): 111-114.
Inheritance of Factors Affecting Floral Primordia Initiation in Cestrum; Hybrids of C. elegans and C. nocturnum
Wesley O. Griesel
Department of Botany, California State College at Los Angeles

Summary. Photoperiod patterns of hybrids of Cestrum elegans (Brongn.) Schlect., a day neutral plant, and C. nocturnum L., a long-short day and long day plant, were investigated. Plants of the F1 generation, F2 generation, and backcrosses to each parent were tested on short day, long day, continuous light, long-short day and short-long day for floral primordia initiation. The data recorded suggest 2 independent genes or gene groups controlling floral primordia initiation in C. nocturnum, a single dominant gene that is activated by long-short day treatment and a recessive gene or genes responding to long day treatment. Further, these data suggest that the day neutral condition in C. elegans is the result of the series of independent genes or gene groups that respond to various photoperiods, the combination of these genes resulting in floral primordia initiation on all photoperiods.

Another example I had misplaced, involving crosses among geographical races of a single species.

Botanical Gazette, 144(2): 231-233 (June 1983)
Photoperiodic Flowering Responses in Hybrid Progenies between Latitudinal Ecotypes of Chenopodium rubrum L.
Takeshi Tsuchiya, Yoshio Ishiguri

Photoperiodic flowering responses in hybrids between latitudinal ecotypes of Chenopodium rubrum, Sel-372 (day-neutral plant) x Sel-184 (short-day plant with a critical night length of 8 h), Sel-184 x Sel-372, and Sel-372 x Sel-194 (short-day plant with a critical night length of 10 h), were examined. In F1 plants, no flowering responses were observed under a 24-h photoperiod but were observed under a short-day, 8-h photoperiod The F2 progenies showed similar photoperiodic flowering responses in all cross combinations: 100% flowering under 8-16-h photoperiod but a drastic drop to ca 20%-30% under 18-h photoperiod and below 20% under 20-24-h photoperiod. These characters in F2 progenies, a drastic drop in 18-h photoperiod and the flowering response under 18-24-h photoperiod, were introduced from a day-neutral line, Sel-372. The flowering response of F2 progenies suggested that the day-neutral flowering response of Sel-372 was constructed from two different flowering responses: (1) a short day with a critical night length of 6 h and (2) 18-24-h photoperiod