I have a bunch (~50) of seedlings of Rb about 6-8 inches tall, from seeds that I got from David Z, for an experiment. They do respond to karrikins with rapid germination, just 2 months from beginning cold stratification. They might make good rootstocks if you can get past the thorns. They are very winter-hardy (e.g. at the Devonian Gardens latitude) and seem to remain free of all the spot diseases around Minneapolis. According to the reported range of the species, they are also drought resistant, and grow at fairly high elevations. I cannot tell you the actual site of collection of this accession, as the pedigree is untraceable. Some accessions were grown in Europe at least 125 years ago. I will over-winter them in my greenhouse under cold, short-day conditions so they won’t get much bigger by March. There are a few dozen more seedlings coming along which will go into the same treatment when they reach the comparable size.
If you are interested in getting some, send me an e-mail. My address is at ksu.edu and name is first letter of my first name followed by whole last name, all lower case. Tell me your proper postal mailing address. I can send up to a dozen of them in the U.S. for about $6.00 in a little priority mail box. Mid-March is optimum shipping time, but I can hold them longer in cold storage.
Rosa beggeriana is interesting beyond potentially being a good rootstock for the high plains. I think it has breeding potential as a source of hardiness.
Firstly, there is some uncertainty whether beggeriana and laxa are one and the same, reticulated cousins, or actual separate species. I’ve been marginially aware of discussions about this and don’t know what the resolution was/is if anything but maybe Peter can shed some light on it.
Alone among the many seeds that I have attempted to extract embryos from, beggeriana/silverhjelmi has proved recalcitrant. The reason is simple - no matter what the state of hydration (or dessication) of the achene, regardless of the sharpness of the tools or the gentleness of touch, the embryos always squirt out like they were being ejected from tiny little toothpaste tubes.
I’m not it a position to test my hypothesis about why this occurs but here it is. I think that the fats in the storage organs, the cotyledons, are highly unsaturated and so are more oily than waxy, waxiness being the normal condition among rose seeds. This might make sense in the tundra where fat mobilization would be enhanced at lower temperatures. It might also explain, partly, why karrikins are more effective than is usual with roses in that fluid endosperm might favor greater solubilization and transport of the molecules over solid wax endosperm.
If I were a biochemist sitting on a surplus of beggeriana seeds I might be able to do some microchemical wizardry to get a handle on any such properties but, alas, I have no bromine water and I flattened all my beggeriana seeds long ago anyway (hundreds of them, iirc).
That’s really interesting Don about the difference in seed texture. Thank you Larry for being willing to share seedlings and for letting us know your results. It was really fun that day collecting those hips together and walking through the rose garden. I should try harder to use this R. beggeriana in crosses. It is diploid. It has been difficult to get a lot of pollen from it and the small blooms have been a little hard to work with. I collected op hips in the past hoping for some outcrosses with neighboring roses, but the seedlings generally seemed just like R. beggeriana. I love the climber (rambler) Polstjarnan (very hardy and large growing) and it is reported as a R. beggeriana hybrid. It is easy to see the similarities with the smaller foliage. There are some similarities with R. laxa and R. beggeriana with the lighter green colored foliage, white blooms, hardiness, and drought tolerance. Differences in flower size, hip shape and size, and general cane thickness and growth are pretty distinct. Peter Harris wrote a nice article a few years back for RHA about ‘Ross Rambler’ and its seed source coming from Kew Gardens if I remember right labeled as R. beggeriana, but instead seems to be R. laxa.
I got this R. beggeriana from Paul Olsen as a sucker a number of years ago.
Hi David… a few years ago you gave me a pot with multiple seedlings that you identified as R. beggeriana. Would Larry’s be of the same heritage?
I planted the whole pot and it has grown into a large bush. Very fine textured and thorny. Some winter dieback of the tips. As you mentioned, hard to work with. I had a seemingly successful few crosses with R. foliolosa, but I think I grubbed those seedlings out because I couldn’t imagine how to move forward from them.
I haven’t used R.beggerina but I suspect it behaves similarly to the other species I’ve worked with (i.e. limited to what pollens it accepts and what it’s pollen will work on). I had Schneezwerg and it is speculated to be a R.rugosa x R.beggerina cross. Like a species, it was selective at which pollen it accepted and even when it did accepted a pollen there wasn’t good hip set. The seedlings from the cross and from OP seeds had week root systems and were quite susceptible to mildew, so I didn’t keep any.
I also used Schneezwerg as the pollen parent in 2014 and it didn’t take on the Polyantha Marie Pavie. It took on a ((Showy Pavement x R.blanda) x (Marie Pavie x R.blanda)) but there wasn’t good seed set, so not a lot of seeds. Finally it took quite well on Metis and there were lots of seeds, it’s just that the seeds didn’t germinate well, so there’s wasn’t a lot of seedlings. I have (8) first year seedlings left from both crosses and they haven’t bloomed yet so they’ll need a couple more years to fully evaluate them.
had a seemingly successful few crosses with R. foliolosa, but I think I grubbed those seedlings out because I couldn’t imagine how to move forward from them.
Incrementally. If beggeriana is a source of extreme hardiness then f1’s with foliolosa would be a leap across a chasm, requiring baby steps to regain balance and find direction. Foliolosa has a lot of potential. One target trait is overproduction of cyanin (and, thus, biochemically downstream anthocyanins when the right cogs and wheels are connected); another target trait is f1 remontancy so pairing it with, say, Suzanne hybrids might be a direction to go.
Hi David do you know what size the flowers are? Or could you use the grid to give an estimation. I have an ugly huge 6footer that when in bloom, it repeats well, one can’t see the wet tissue 1.5 cm flowers. Also the hardiest rebloomer I have and is rather fertile. My F1s are hardy and fertile and some are rebloomers.
As a side note Snow Dwarf is not very hardy for me. I curious about the provenance of my beggeriana. Johannes
There is an article last year indicating that Rb is diploid and Rl is tetra, with rather similar karyotypic characteristics, so may be close relationship. Getting from the Chinese to English it was left open whether Rl is just a doubled form of Rb.
Karyotype and Flow Cytometry Analysis of the Natural Populations of Rosa beggeriana and Rosa laxa in Xinjiang, China
S. Yang, Y.J. Han, S.H. Yang and H. Ge Institute of Vegetables and Flowers Chinese Academy of Agricultural Sciences Beijing 100081 China
Keywords: karyotype, population, Rosa beggeriana, Rosa laxa, Xinjiang Abstract
As the typical local rose species in Xinjiang, R. beggeriana and R. laxa are highly similar in the morphology except that the sepals are deciduous in R. beggeriana while they are persistent in R. laxa after hips ripening. Both species had been applied to interspecific hybridization with modern rose cultivars for the introgressions of stress-resistances. In this study, R. beggeriana from three populations and R. laxa from four populations varied with different altitudes had been selected for ploidy and karyotype analysis. The results showed that the populations of R. beggeriana and R. laxa are diploid and tetraploid respectively. The karyotypes of seven populations of two species are all identified as the small chromosomes types, which belong to original, symmetric and ‘2A’ types. Moreover, different karyotype diversity was found in the populations between R. beggeriana and R. laxa.
Proc. 6th IS on the Taxonomy of Cultivated Plants Eds.: Qixiang Zhang and Xiaobai Jin. Acta Hort. 1035, ISHS 2014. pp 205-213
If I were going to try breeding with Rb, I’d use Rainbow KO as a pollen donor. Pink Clouds made seeds, when poll by RKO, but none have germianted yet in over a year of waiting. New Dawn made seeds that do germ, but might be tetra of course.
Larry, the article to which you refer (Hong Ge was the corresponding author) characterizes two specimens of R. laxa, both growing in the same garden. Quite a while ago I wrote to Hong Ge, asking to see images of the roses examined. After several months there has been no response.
Although at one time the conventional wisdom was that R. laxa, Retzius was tetraploid, Flora of China and other sources have listed it as diploid, and the R. laxa collected by Niels Hansen and used by Buck and Skinner was (and is) diploid.
Certainly there has been confusion of R. laxa and R. beggeriana, notably at Kew in the late 1800s (and subsequent to that, in Canada, when R. laxa seeds labeled as R. beggeriana were received from Kew).
Other recent studies of the roses in Xinjiang have confirmed that R. laxa exists in both diploid and tetraploid forms. A tetraploid beggeriana would be interesting, but so far I’ve seen no report that one has been found in the wild. Maybe you could double what you have there and see if it resembles R. laxa.
J. AMER. SOC. HORT. SCI. 139(1):39–47. 2014.
“Karyotype Analysis of Wild Rosa Species in Xinjiang, Northwestern China”
(Chao Yu, Le Luo, Hui-tang Pan, Yun-ji Sui, Run-hua Guo, Jin-yao Wang, and Qi-xiang Zhang)
This 2014 article identifies both diploid and tetraploid genotypes of R. laxa. All specimens of R. beggeriana were diploid.
Page 42 of the article features color photos of flowers and hips of a representative sampling of the roses examined in the article. Rosa beggeriana hips are either round and pea-shaped or olive-shaped, and may be red or nearly black when ripe. Rosa laxa hips are spindle-shaped, elongated, with a narrow neck. There is little apparent resemblance between the hips of laxa and beggeriana.
Here is another article which reports both diploid and tetraploid genotypes of R. laxa in Xinjiang, Northwest China:
“Discussion and Analysis of the Karyotypes of Rosa laxa in Xinjiang”
YU Chao, LUO Le,WANG Yun-hong, LIU Jia, PAN Hui-tang, and ZHANG Qi-xiang Acta Botanica Boreali-Occidentalia Sinica 2011 (12) 2459-2463.
【Abstract】Karyotypes were studied via squash method in 5 Rosa laxa germplasm resources
from Xinjiang. The results showed that ploidy levels were divided into diploid (2n=2x=14) and
tetraploid (2n=4x=28). Asymmetry index ranged from 55.14% to 60.11%.The karyotypes of all
the test materials were made of m and sm chromosomes, which include 1A, 2A and 1B.The
results indicated that the existence of different ploidy levels is associated with the different
regions and habitats where the germplasm resources grow. Karyotype of material No. 5 showed
obvious difference with others, which was tetraploid, top asymmetry index and the most evolved
karyotype. It was consistent with the previous view by Liu Shi-Xia that Rosa laxa var.
tomurensis S. H. Liou should be placed as a new variety of R. laxa, while material No. 4 was
regarded as another variety, R. laxa var. kaschgarica (Rupr.) Han, which had already been
approved by Flora Xinjiangensis.
Acta Horti Bergiani, Bd 7. no. 3 (1922)
Zytologische Studien über die Gattung Rosa
38. R. laxa Retz. det. Almquist. Turkestan, Dsungarei, Altai. (Kew: R. l. Siberia). Nach Almquist ist dieses Spezimen und überhaupt die ganze Art laxa als die Hybride beggeriana X cinnamomea anzusehen. Die Tetradenteilung der PMZ erfolgt regelmässig. In den Diakinesekernen können 7 Gemini gezählt werden. Ein tetraploider, auch als laxa bestimmter Strauch wird als Nr. 117 erwähnt.
“According to Almquist this specimen and indeed the whole type laxa is to be regarded as the hybrids beggeriana X cinnamomea.”
“A tetraploid, certain as laxa shrub is mentioned as no. 117.”
Well, there’s obviously a challenge out there in the world of collections. The article I cited referred to four different R laxa and three R b. populations from different locations (elevations). I haven’t traced the pairing up of author names to see how much overlap there may be between the various Chinese groups. There may be some competition involved to have so many papers so close together in time. They get merit pay for publications, based on the impact factor of the journal. Too bad for me that all the articles seem consistent in seeing R. b as diploid. That adds another generation or so to any breeding effort in my view.
Don, your idea of high levels of unsaturation is interesting, but I don’t think it accounts for the odd behavior of the seeds. Last night I did some internet searching and found that rose seed oil from several sources whether R moschata or R canina, is very unsaturated, like sunflower of flax seed with up to 77 % of fatty acids begin linoleic or linolenic. However the total oil content is below 10 %. I’ll see if I can dissect some Rb seeds. However I’m already well above 50 % germ with high kar1 and far lower with nitrate or water. First species where nitrate is not better than water in my experience. I need to wait another year to see how it comes out in the end.
I don’t see noticeable variability in the seedlings so far. All have many straight spines right up the stem. Of course I need to let them get bigger to find out the habits of mature specimens. Meanwhile, if anyone wants some plants next spring, let me know.
I’ve always liked the idea of interspecific crosses between cold hardy North American and Asian species to develop new types of roses. Most of this work, of course, has been done with Rosa rugosa and the North American species Rosa nitida and R. woodsii. However, I think combining Rosa beggeriana, R. fedtschenkoana and R. laxa with, for example, Rosa woodsii and R. palustris would be interesting to do. An option could be then combining some of these hybrids with Rosa rugosa to improve flower size and perhaps obtaining at least some repeat bloom.
“According to Almquist this specimen and indeed the whole type laxa is to be regarded as the hybrids beggeriana X cinnamomea.”
Karl, this is really interesting. Perhaps when the costs come down a bit more and the DNA technology gets commodified this conjecture can be tested.
I’ve always liked the idea of interspecific crosses between cold hardy North American and Asian species to develop new types of roses.
Indeed. This is what I am up to with virginiana and woodsii f., and with a couple pisocarpa f1’s although I favor fully refined partners over species. The trick is, of course, choosing those partners wisely and getting lucky despite your wisdom.