A quick question.
With R. canina varietites and their weird and wonderful chromosome configuration, do the bivalents only have the influence of the plant growth and characteristics or do the univalents have some say in the matter as well.
Cheers Warren
I thought some of the scholastic wonders on this forum would have been able to help, maybe not LOL
Well, I’m not the one to give any sort of educated reply, but it is well after midnight in much of the states, and on a weeknight, so I would give it a little more time! LOL. I’m looking forward to the scholastic replies too. 
I’ve been enjoying the info you’ve been sharing on your work, Warren.
Warren,
I read your note last night, just before I went to bed. It was too late for me to be “scholastic” … or even entirely coherent.
I have been trying to find a note I read that Rosa rubrifolia does not pass its leaf color through its pollen. It certainly does through its seeds, as Wright, Preston and others have reported.
Caninae species have been crossed with other Caninae species, and with “regular” species, in both directions. The reciprocal crosses are not the same.
I did a quick Google search on … reciprocal hybrids caninae
https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1601-5223.1945.tb02765.x
“Especially interesting are the crosses R. canina II X rubiginosa and reciprocal. These hybrids have been described at some length in the paper by GUSTAFSSON (l.c.). The reciprocal two hybrid series are quite dissimilar in morphology, as well as habit of growth, winter hardiness, and so on.”
https://www.researchgate.net/publication/226345692_Inheritance_of_growth_form_and_mechanical_characters_in_reciprocal_polyploid_hybrids_of_Rosa_section_Caninae_-_Implications_for_the_ecological_niche_differentiation_and_radiation_process_of_hybrid_off
“Within Rosa section Caninae (dogroses) two different growth types exist, arching (L-type) and erect (D-type). Due to the specific mode of chromosome allocation during meiosis, character inheritance in dogroses is maternally skewed. In this paper we try to assess the mode of inheritance of the ‘growth form’ in reciprocal hybrids of R. canina L. and R. rubiginosa L. to predict possible ecological niches and radiation processes of hybridogenic offspring.”
The fact that reciprocal crosses are different is clear evidence that the unpaired chromosomes are active.
So if a pentaploid caninae rose has 35 chromosomes and an apple tree has 34 chromosomes, you should be able to put apple tree pollen onto that rose because it’s close enough, right?
Just trolling you scholars. It was actually a thought that I had, but I realize it makes no sense. And I’m hijacking the thread. So just ignore this.
A little, perhaps. Roses typically have chromosomes in groups of seven. Apples and other pomes have chromosome sets based on 17. However, internal evidence (secondary pairing) suggests that this 17 based on 7 + 7 + 3.
One plausible origin for this peculiar number is that one ancestral line with x=7 gave rise to x=8 by duplication of one of the existing chromosomes. This is the the number found in Prunus. And in a separate lineage, 2 different chromosomes were duplicated giving x=9, like Spiraea.
It is interesting to look at the various pomes and try to imagine how a Prunus and a Spiraea might be brought together to produce them. For example, the Loquat looks like it might have a peach in its background: large seeds, fuzzy orange fruit, elongated leaves, etc. I couldn’t guess about the other hypothetical parent.
thanks every one
The Caninae species have not been used to full advantage. Some of the desirable traits (foliage color of R. rubrifolia, foliage fragrance of R. rubiginosa) might be had by “breaking” the species.
Blackhurst: Rubiginosa Hybrids (1948) pollinated R. rubiginosa by an assortment of other species and observed the breakdown of the Caninae-pairing. He did not continue past the F1 generation, which is a pity.
http://bulbnrose.x10.mx/Roses/Hurst/BLKHURST.HTM
Heslop Harrison: Durham Wild Roses (1954/1955), on the other hand, demonstrated that R. rubella and R. rivalis, both tetraploid species, could be duplicated in the F2 generation from R. sherardi x spinosissima.
“Professor Heslop Harrison emphasized that the F1 lots, whilst conforming, in a general sort of way, cytologically to the usual Caninae pattern, in their later meiotic stages on the female side showed important anomalies. As a result, amongst the seedlings, orthoploid plants were secured carrying chromosome complements of 14, 28, 35 and 42. Thus it was clear that a new polyploid series had been evolved by a distinctly novel mechanism. Further, amongst the seedlings there were encountered aneuploid plants with chromosome numbers 2n=24, 2n=32 and so on.”
http://bulbnrose.x10.mx/Roses/breeding/Durham.html
There was high mortality, so it might be helpful to have some seedlings available to use as root stocks.
Karl, perhaps a dumb question, but I noticed in both the laevigata thread and in this one that you apparently attribute seedling mortality in some wider crosses to the plants foundation, as evidenced by your suggestions of rootstocks for said seedlings. Is that accurate? Why the supposition that grafting might alleviate the problem, if I may ask? And how early would most such seedlings fail?
Thanks.
Philip,
Actually, those are good questions.
I have come across cases in other families where the storage materials are incompatible. This may mean that some pollen tubes can’t process the starch (for example) provided by the prospective seed parent.
http://bulbnrose.x10.mx/Heredity/Collins/CollinsChinese1909.pdf
Or grafts may fail for the same reason.
http://bulbnrose.x10.mx/Heredity/Daniel/Daniel1901.html
In other cases the cause of the incompatibility is currently unknown (to me).
American Rose Magazine 1(10): 3-5 (July-August 1934)
Rose Understocks
ROLAND G. GAMWELL
The lovely hybrid Bracteata, Mermaid, hesitates to accept any stock, willingly but with least objection unites with Rugosa.
http://bulbnrose.x10.mx/Roses/breeding/GamwellStocks1934.html
I don’t know whether ‘Mermaid’ could be used as a root stock.
Michurin’s hybrid of Kazenlik x Persian Yellow is a special case of weird.
(Results of Sixty Years’ Work. 1934) Selected Writings, p. 263
Ivan Michurin
“This method [grafting seedlings] often has to be resorted to when the structure of the hybrid’s root system happens to be poor. This was observed, for example, in the case of a new variety of the attar rose Slava Sveta. The hybrid seedlings obtained from fertilizing the yellow Persian rose with the pollen of the Damask rose rapidly perished, even before they attained a height of 5 cm., owing to the poor development of the root system.” [CybeRose notes: This may be a mistranslation. In other reports, ‘Kazanlik’ is said to be the seed parent.]
http://bulbnrose.x10.mx/Roses/breeding/MichurinSlavaSveta1913.html
Fortunately, Michurin had some Canina seedlings on hand.
American Rose Annual 1977
Breeding With Hulthemia Persica (Rosa persica)
Jack Harkness
“Two seedlings of H. persica x R. rugosa alba also failed. Probably no two diploid species of roses are more dissimilar than H. persica and R. rugosa; at all events the seedlings from that cross try to make leaves from the seedling stem at intervals of 3 or 4 mms, and their effort exhausts them before they are very high.”
http://bulbnrose.x10.mx/Roses/breeding/Persica/PERSICA.HTML
Hi,
I believe this article might be of some interest:
It states that
“Evaluation of phenotypic variability revealed that the two taxonomically relevant characters “widening of the orifice” and “persistence of the sepals” are statistically significant controlled by the pollen donor. Reciprocal crossings confirmed the same pattern”
I love Caninae section species. When I started breeding roses in the 1980’s I was in awe of the fragrant foliage of R. eglanteria. I tried it as a parent with modern roses and the only direction crosses would take is with it as a female. Many of the supposed hybrids looked like the mom, but that is expected. The ones with extra petals were a good clue they were hybrids. Eventually I counted some chromosomes and found some hexaploids (5x eglanteria x 4x modern roses- 4 sets from mom + 2 sets from dad). The pollen had the diameter expected for being 2x- like albas. I tried the pollen on modern roses, but it didn’t take well and the limited seedlings were weak and didn’t survive.
This spring there are a couple seedlings of the hexaploids crossed with a modern shrub rose again. The foliage looks more modern rose like and the foliage still has pretty good fragrance. Some hybrids though in the past have lost most of the fragrance. My hope is to go enough generations to hopefully get some repeat bloomers that have fragrant foliage.
I would guess, based on Heslop Harrison’s observations, that the pollen has a major influence on which chromosomes/genes are recovered in the F2. At least in the viable/fertile selections. In that case, pollinating the Sweet Briar by something other than the usual garden roses might bring the “fragrant leaf genes” into a more obliging tetraploid.
‘Lady Penzance’ has fragrant foliage, and bears hips. Has anyone tried raising seedlings from them?
Hey Karl. I like the way you think… I am quite surenit is possible to bring the fragent leaf genes into a tetraploid. Not sure though it is easy to obtain a fertile tetraploid though, so the genes can be passed on to its offspring…
I have 2 seedlings of Magnifica, open pollination. But they are very tiny. Not sure what to expect though but hopefully they will have some repeat bloom as well as the apple fragrance in their leaves.
I have some ideas about which wild roses can be used on rosa rubiginosa so the f1 hybrids will be able to ‘free’ the fragant genes. My thinking is based on the septet theory of Hurst. But I know… most people here feel Hurst was wrong… I still believe there is some truth in his observations though.
The more important thing though is to locate on which septet, chromosome, the scentes leaf genes are to be found… Or would it be a combination of genes? If that is the case, it makes things a lot more complex…
I am working with Lord Penzance, Lady Penzance will be coming in the next few months. Given a few comments on here i shouldn’t expect germination until the second season so probably wont be til next year to see if any of the couple hundred Lord P seeds germinate…but it’ll be one of the main areas I’m focused on. Will likely add R. micrantha when i can get access to it also.
While i havent seen the following in person (not available in Australia) but technically hasnt tetraploid with briar fragrance been achieved via Goldbusch, Applejack and RADsweet…granted reportedly a bit difficult to work with but they all have children…
I haven’t seen or smelled these. RADsweet is listed on HMF as triploid, Still, it might be worth crossing with ‘Lady Penzance’ or other.
That’ll teach me to not look it up while on the train to work. Still it is a fertile triploid so should be less difficult to work with.
They all trace back to Magnifica. On a slight tangent everything in my signature has some connection to one of the three. Given RADsweet I wouldnt be surprised if its hidden in a lot of Raddlers roses as a recessive trait or something.
There was a group of botanists who were so involved in studying the quantity and distribution of pubescence on the under side of leaves, that they could not be bothered to look and multiple traits at one time. Hurst found sets of 50 traits. Fifty is more than a handful.
Another point is that few botanists were even willing to consider that when two species are hybridized, the numerous individual traits can be compared with the corresponding traits of the parents. Hurst got started on this sort of analysis working with Paphiopedilum hybrids, examining only 20 traits:
(1) The habit of growth; (2) the habit of flowering; the form or shape of the (3) leaves, (4) scape, (5) bract, (6) ovary, (7) upper sepal, (8) lower sepal, (9) petals, (10) lip or slipper, (11) staminode; the colour of the (12) leaves, (13) scape, (14) bract, (15) ovary, (16) upper sepal, (17) lower sepal, (18) petals, (19) lip or slipper, (20) staminode.
He then weighed the approximate contribution of the parents to each trait.
Each of these parts or organs of the hybrid has been compared with the same part of each of the parent species. Each part is then classed in relation to the two parents, either (a) in the ratio as 1:1, which represents the part as fairly intermediate between the two parents; or (b) in the ratio as 3:2, which represents one parent to be slightly predominant in that particular part; or (c) in the ratio as 2:1, showing the decided prepotency of one parent in that part; or (d) in the ratio as 3:1, showing the very large prepotency of one parent in that part. In this way the twenty parts are classified, and when the various figures are added together one can see at a glance the total ratio of one parent to the other in the hybrid. In the following condensed analyses I have ignored, for the sake of simplicity, all the ratios as 1:1 and also those as 3:2, classing them as intermediate or thereabouts, and only showing the undoubted prepotencies of either parent in the ratios as 2:1 and over. At the end of each are given the full ratios of the plant as a whole, as originally analysed, with the corresponding percentages of the predominant parent, for the sake of comparison.
http://bulbnrose.x10.mx/Heredity/Hurst_partial_1900.html
In making this sort of analysis, Hurst became experience seeing the interaction of multiple traits simultaneously.
For doubters, we may ask why Synstyles have not (apparently) participated in the formation of polyploid species. Then we may ask them to examine Basye’s Probable Amphidiploid for signs of its R. abyssinica parentage.
And before I forget again, here are a couple of pictures of a found rose tentatively tentatively identified as “Reblooming Anemone”. The top picture is the typical form of this variety. The lower is a very odd “freak” branch growing on the same plant at the same time. The mass of little prickles leads me to wonder whether this is Burbank’s Rugosa x Laevigata hybrid.
This sort of thing happens from time to time, and can give hints of the hidden genetic makeup of a plant.
“we may ask why Synstyles have not (apparently) participated in the formation of polyploid species.”
A very good question, in the last couple of years I have been using roses from Synstylae or its offspring. Even at the level of F3 you can still see some influence of Synstylae stigma’s.