New article on repeat bloom

This is a great article that advances some of the previous work from this team in France understanding the key gene for repeat bloom and variants of it and suggests there are additional factors/genes governing repeat bloom yet too in some of the roses with more modest rebloom as well.

https://www.nature.com/articles/s41438-021-00512-3

Thanks a lot for sharing. Fascinating. A lot of variability in RoKSN locus and the history of Cinnamomea –> Rugosa –> moschata are very interesting.

Seems to line up with a number of things posted on the forums in recent years.

Potentially useful info for hardy breeders in there for some copia sources.

Also of note is Belle Poitevine and R.Rugosa having the same WT A181 setup as Cristata/Crested Moss given the difference in blooming, unsure what that

I find the paper to be … puzzling, at least.

"Although the geographical distributions of the two roses are separated39, we hypothesize that R. moschata has a wild ancestor related to R. rugosa (Supplementary Fig. 4). Rosa fedchenkoana has the RoKSNA181 allele with the weak reblooming characteristics (Supplementary Fig. 2) and is placed in the section Cinnamomea together with R. rugosa_36, and is therefore a putative wild ancestor of R. moschata._ "

First off, Rosa rugosa i(the real one) is said to be a once-bloomer, with solitary blooms and only the occasional late bloom. R. moschata, as I knew it at the Heritage Rose Garden, San Jose, CA, blooms continuously from April to autumn.

Rosa fedtschenkoana managed to escape the attention of humans until the late 19th century. And yet some folks are anxious to insert it into the history of modern garden roses. I suspect some of this push is based on Bieberstein’s incompetent handling of a rose he found in the rocky, southern Taurus Mountains.

In his Flora Taurico-Caucasica, tome 1, no. 974 p. 396 (1808), the species was identified as R. provincialis. But in Flora Taurico-Caucasica: Supplementum, tome 3, p. 339 (1819) he re-identified the species as the Rosa ferox of Miss Lawrance.
http://bulbnrose.x10.mx/Roses/breeding/Bieberstein.html

After I dug up this mess, I learned that Crépin (1860) had got to it before me … but it seems no one listened to (or read) him.

And so we are left with these oft repeated legends of Rugosa and Centifolia growing together in the Caucasus [!] mountains, or in Asia Minor. I am still surprised, just a bit, that Bieberstein’s “rocky southern Taurus mountains” turned into “eastern slope of the Caucasus Mountains”.

Paxton’s Magazine of Botany, and Register of Flowering Plants p. 34 (1848)
[From “An Essay on the Geographical Distribution of Plants,” by N. I. Winch, Esq.
On the other hand, the Provence Rose (Rosa centifolia) and the Officinal Rose (Rosa gallica), said to be from the south of France, but most probably originating from Asia Minor, and the Damask Rose (Rosa damascena) from the same country, are to be met with in every garden; nor is the Musk Rose (Rosa moschata), of the north of Africa, very scarce.
[The original Damascene rose was Rosa moschata. The more common pink Damask roses are derived, long ago, from seeds of the Musk rose.]

The Book of Garden Management … (Beeton’s Garden … - Page 600 (1870)
Samuel Orchart BEETON
As we approach the North and West, we find in the Caucasus Rosa centifolia. … Rosa ferox mingles its grand red flowers with it, and Rosa pulverulenta is remarked on the declivities of the peak of Mazana, a spur of the Caucasus. [Bieberstein (1808) wrote that it lived in the hills around Narzana]

A Practical Treatise on Animal and Vegetable Fats and Oils: … p. 512 (1896)
William Theodore Brannt
The Crimea is also well adapted for this purpose [collecting rose oil], especially as Rosa centifolia is said to grow wild in the mountains.

Bulletin of Miscellaneous Information - Page 193 (1894)
Omar Khayyam’s Rose:
The plant proves to be a form of Rosa centifolia, the sweetest scented of all the roses, from which the cabbage rose, the moss rose, and the pompon are derived. The native country of the plant is not known with certainty, but it was considered by Bieberstein to be truly wild in the Caucasus, and was found by Haussknecht in a semi-double form at an elevation of 3,500 feet, amongst the mountains of Assyria.

The Century Dictionary: The Century dictionary - Page 5230 (1911)
White rose. (a) The badge of the house of York. (b) Specifically, Rosa alba, a garden rose, native in the Caucasus.

Gardeners’ Chronicle of America - Volumes 48-49 - Page 203 (1944)
Rosa centifolia: A plant explorer about 1800 found it growing wild on the eastern slope of the Caucasus Mountains, between the Black and Caspian Seas.

Rose Growing Complete (1976)
E. B. Le Grice
This Rose de Mai was a hybrid between R. centifolia (from Asia Minor) and Rose de Provins (R. gallica) which is said to be indigenous, although it is believed that Theobault IV brought back from Damascus to Grasse a type of Rose de Provins with a reddish purple flower.
[He also brought “a piece of the true cross”, so treat this story with the skepticism it deserves.]

BEWARE OF SYNONYMS

I got caught in a synonym trap, though I should know better by now.

Rosa provincialis is a synonym R. centifolia … except when R. centifolia is synonym for R. damascena … or for R. gallica.
I was so wrapped up in Bieberstein’s confusions regarding R. provincialis and R. ferox that I didn’t notice that he also reported finding R. centifolia.

Because he thought he already had R_. provincialis_, then the R. centifolia must have been R. damascena. Boissier (1872) seems to agree, but I’m having trouble translating his observation:

Obs. R. Damascena Mill. Dict. no. 15 a praecedente aculeis omnibus validis inaequalibus, sepalis sub anthesi reflexis distincta, ex Syriâ ab auctoribus antiquis oriunda dicitur, sed eam nunquam spontaneam vidi.

Lindley (1820) mistranslated Bieberstein’s comments, apparently unaware that he was discussing a Damask rather than a Cabbage Rose. “I prefer, therefore, to place its native country in Asia, because it has been found wild by Bieberstein, with double flowers, on the eastern side of Mount Caucasus, whither it is not likely to have escaped from a garden.”

Wrong!

In fact, Bieb. wrote: Habitat in Caucasi orientalis nemorosis. [Habitat in the woodlands of the eastern Caucasus mountains.]

I have never been to the Caucasus, but I have seen that people happily live in the woodlands of the Smoky Mountains, where I saw Rosa multiflora growing “spontaneously”.

Thanks to modern DNA studies, we know that the Damask roses are descended from a seedling of Rosa moschata. Thus, the place of origin is likely to be some place where Musk roses grow. In India, perhaps.

The History, Antiquities, Topography, and Statistics of Eastern India vol. 1, p. 289 (1838)
Behar (Patna City) And Shahabad
Robert Montgomery Martin

The rose, which is cultivated in these gardens, is said to have originally come from Busorah, and at Patna is called by that name; but in Bengal it is called the Patna rose. It does not seem to differ materially from the common red rose of European gardens (> Rosa gallica> ). It is propagated by cuttings in the rainy season. The cuttings are planted in a bed until they take root, and are then placed three or four together in one hole, the holes being from two to three cubits distant. Every two or three years the bushes are pruned. They flower from the middle of February to the middle of May, and must be watered in the dry season. The flowers, which are rather smaller than those in Europe, sell to the distillers at from 1000 to 4000 for the rupee.
Martin: Bussorah or Patna Rose (1838)

Bloom time and Habitat
I’ve been struggling through the Latin text of Dominique Chabrée’s (1566) descriptions of roses. One of these is of particular interest: Rosa moschata maior.

Lugduni & Monspelij Maio & Autumno floret. In Italia toto anno nonunquam florete, scribit Gesnerus. Nos verò Ebroduni in Domini Chasseur horto, à mense Augusto in Hyemem usque florentem observavimus.

With the help of Google translate, I get this:

Lyon & Montpellier May and Autumn blooms. In Italy sometimes blooms all year, writes Gesner. But indeed Ebroduni in statements of Domini Chasseur garden, even in month of August in winter flowering observed.

The first two sentences are easy enough. This species was twice-blooming in some places, more-or-less everblooming in Italy. The last sentence has me stumped. Ebroduni refers to a city in Switzerland, and Chasseur may be a surname. But how did August get into winter?

page 107

The main point, here, is that this Musk rose was not a cluster-type. Judging only from the illustration, the blooms were solitary or paired.

Rosa moschata minor is more like what we have now. Chabrée wrote that it bloomed at the same time as the previous. It is at least an interesting coincidence that these two varieties/species should bloom at the same time unless they are connected by lineage or ancestral habitat.

I found the one short blurb on reblooming climbers explained a great deal of theory.
Thank you very much -I thought that all rebloomers were the same.

As a side note what about Rosa begeriana? I get constant bloom from from June until frost. The flowers are inconspicuous but there Is so much potential. Is this ignored?

That is wonderful!! I got some R. beg. seed from Paul Olsen years ago. I have to see if I still have some plants with the moves in pots. Those weren’t free flowering for me. It would be great to get more Cinnamomeae section species that repeat some to see which allele they have and if they all share the same one.

Change in altitude can provoke some changes in habit. For example, Rosa sericea pteracantha is supposed to have four or five petals. But when grown at San Jose, CA, the number of petals can increase remarkably … and irregularly … on a single cane.
http://bulbnrose.x10.mx/Roses/Rose_Pictures/Rosa/R_pteracantha.html

The once-famous Monthly Strawberry is native to the Alps, and is adapted to a short growing season. And because the changes of season are not (I’m guessing) disrupted by frequent warm spells during the Winter, these plants don’t need a persistent dormancy to keep them asleep. And so, the small plants that grow on the runners can go ahead and bloom and bear fruit in the same season.
Williams: Monthly Strawberry (1824)
http://bulbnrose.x10.mx/Heredity/WilliamsStrawberry1824.html
Mawe: Monthly Strawberry (1778)
http://bulbnrose.x10.mx/Heredity/MaweStrawberry1778.html

Tom Silvers found a plausible connection between Alpine species and rebloom in Tall Bearded Irises.
Silvers: Rebloom’s Alpine Connections (2014)

And sometimes the reblooming character turns up in hybrids though neither parent expresses it.
Johnson: Flathead Lake Penstemon (1951)
http://bulbnrose.x10.mx/Heredity/JohnsonPentemon1951.html

Laidback Gardener: Everblooming Daphne (2016)
http://bulbnrose.x10.mx/Heredity/LG_Daphne2016.html

Tripp, Raulston: Prunus Autumnalis (1995)
http://bulbnrose.x10.mx/Heredity/TrippAutumnalis1995.html

Nakano: Dianthus-Gypsophila Cybrid (1996)
http://bulbnrose.x10.mx/Heredity/NakanoCybrid1996/DianthusCybrid.html

I almost forgot. Burbank crossed the annual Opium poppy (Papaver somniferum) with the perennial P. orientale. The result was a family of perennial poppies that bloomed almost all year long, at least in California.

Another old synonym: Rosa Persica

Valerius Cordus (1561) German
Rosae Alexandrinae, vel Persicae, vel Damascenae, vulgò Incarnatae dictae, ante annos aliquot rarae nobis, nunc satis frequentes. Lybfarb rosen.
Alexandrian roses, or Persian, or Damascena, commonly called Incarnatae [i.e., Pink Roses], were seldom seen with us several years ago but are now common.

Chrostoph Wirsung (1577) German
Rosa Persica = Provins Rose. However, he also identified Rosa Incarnata Herbariorum and Leibfarbe Rose as Provins Roses.
Wirsung’s Damascena was the Musk rose.

Pietro Castelli (1640) Italian
Rosa incarnata. Rosa Trachinia Plinii. Bauh. Rosa pallida Lob. Rosa sativa purpurea Caes. Rosa zebedena offic. Rosa Alexandrina Hispan. Rosa persica Frag. Rosa solutiva Calestano. Rosa Damascena. Colleg Bon.

In these three authors there is the familiar confusion of Provins Rose with Damask Rose with Musk Rose. Otherwise, this is another example of how names can change as a plant is moved from place to place. Damascena suggests that a plant came from Damascus, but Alexandrina and Persica, applied to the same plant, imply that the plant got around.

I also did a bit more searching into Alpine plants and how they sometimes change when moved to lower altitudes. I hadn’t considered atmospheric pressure, but then I remembered something Ivan Michurin wrote:

In some years, in the latter part of August, there is a long period of constant high atmospheric pressure (between 760 and 770 mm). This, according to my observations, greatly affects the organisms of perennial plants and forces some of them to bloom again in the autumn.

In such cases, > certain varieties > of apple, cherry, mountain ash, bird cherry, and others have a second budding.

I emphasize the “certain varieties” because this points to an important phenomenon that was well known and discussed a century ago, but was dismissed by the Neo-Mendelists. O. F. Cook (1907) called it “Neotopism.— Vari­ations induced by the transfer of organism to new and unwonted conditions. Three stages of new place effects may be distinguished, (1) those in which there is merely a stimulation of growth, (2) those in which there is also a definite mutative change of the hereditary characteristics of the variety, (3) those in which the new conditions call forth a promiscuous mutative diversity.”
http://bulbnrose.x10.mx/Heredity/Cook/Cook_Kinetic/Kinetic2.html

At that time, no one was ready to propose a workable theory to account for something so easily observed. Now we know that changes in external conditions can alter the expressions of a plant’s genes. Nagy & Grabherr (2009) wrote, “There has been some recent experimental work on plant physiology in extreme hypobaric environments (e.g. Paul et al. 2004). The interesting finding from these studies was that low pressure caused the expression in Arabidopsis of about 200 genes, of which less than half were prompted by hypoxia alone, too.”
http://bulbnrose.x10.mx/Heredity/NagyAlpineAir2009.html

If these genes were not usually expressed at ordinary atmospheric pressure, we should not be surprised to find mutations that were not previously observed. The same applies to plants exposed to increased pressure. Some may respond differently than others, even those of the same species.

In the case of Rosa species raised from seed collected in the mountains, some may give late blooms while others collected at the same time and same place may be as stubbornly once-blooming as expected. The same goes for hardiness. Erlanson (1934) wrote: “Seedlings of R. blanda from northern Michigan segregated into tender and hardy individuals at Ann Arbor, 300 miles south of their natural habitat.”

ISHS Acta Horticulturae 1064: VI International Symposium on Rose Research and Cultivation (2015)
MOLECULAR GENETIC STUDIES ON CONTINUOUS-FLOWERING ROSES THAT DO NOT ORIGINATE FROM ROSA CHINENSIS
T. Horibe, K. Yamada, S. Otagaki, S. Matsumoto, K. Kawamura
“KSN genotyping demonstrates that the continuous-flowering species R. rugosa does not have the mutated allele of KSN as is present in R. chinensis.
http://bulbnrose.x10.mx/Roses/breeding/HoribeRoseRebloom2015.html

Another neglected rebloomer is Rosa x hibernica, reportedly blooming from early June to mid-November. Crossed with HTs, it has given some attractive reblooming shrubs: Innocence, Irish Elegance, Irish Fireflame, Isobel.
http://bulbnrose.x10.mx/Roses/Rose_Pictures/Rosa/R_hibernica.html

Before I forget again, I would be interested to learn how Rosa moschata behaves in different climates. In San Jose, CA, it blooms continuously from early April until late October at least (I have pictures).