So here is a question I have been wondering about recently. How many of the species sold in commerce are the same clone or come from the same clone and how many are very diverse from one source to another?
When I look at wild species growing naturally even in a very small population there is much variety. For example I know a stand of R. woodsii that is in an area of probably 20 yards square. In this stand the flower colors differ from dark pink almost red to such a light pink that it fades to white by mid day after opening. The stems in this stand go from completely thornless to one plant that had no thorns that I could find. Lastly R. woodsii while remaining disease free overall surfers sometimes with rust and galls. In this stand you also see variation to how much these effect them. In general most of the plants in this stand are all about the same but a few here and their are different enough to warrant my attention particularly the thornless one which I hope to obtain pollen from in the spring and cross it to a thornless R. foliosa.
So what are you thoughts? If one where to by R. wichuriana or some other species what is the likely hood that they are all so similar it does not matter where you obtain them from or are there some very superior clones out there? And with species that originally come from say china or japan how much of a bottle neck do we have with these species? Could some of these species have a much superior plant material out there somewhere in china or where ever?
I have thought of this a few times. My clone of Rosa canina is a naturalized seedling that probably originated from understocks crossing with each other pre-1970s. My Rosa rubiginosa is understock from Canada, lol, so I have no clue what its source is but I am assuming it is different that buying it from Forest Farms or elsewhere.
Rosa rugosa and all the cinna’s are prolly okay. I am guessing that roses like R. wich, R. moy, R. seri, R. foetida or R. fed , etc etc are more lilkely to be clones. It probably depends on ease of seed production vs. desire to actually raise seedlings from the species itself. Also, its native origin may also lower the likelihood of multiple clones. For example, R. wich is like R. rugosa and R. multiflora in its origin (overseas, SE Asia) but it isnt quite so, uhm, “slutty”
with species that originally come from say china or japan how much of a bottle neck do we have with these species?
This is a hugely important question.
Could some of these species have a much superior plant material out there somewhere in china or where ever?
Yes, especially with respect to non-morphological traits such as insect and disease resistance and climate tolerance but also simply because clones accumulate genetic errors over time.
For my winged thorn program I assumed that plants of Sericea in commerce were from one or a few clones so I also sought out plants from botanical gardens whose accessions were documented as being unique, and from collectors who had gone to China. Besides crossing these plants with modern roses I am also crossing them together to build up a more diverse breeding population.
There’s no easy answer to the genetic diversity question and it will vary by species. Some of the species were specifically introduced by the USDA, or Arnold Arboretum or other identified sources. Often a single explorer like “Chinese” Wilson went out and collected. He tried to get multiple accessions, but there was selection in what was released to nursery growers. This is documented well for some shrub species other than roses. I suspect that van Fleet used a single clone of R wich for his work, for instance. I don’t know about Schoener and his work in CA during the 1920s. Most other breeders have done the same, depending on a single accession, whatever they could get their hands on. I think this is pretty well documented in the history of rose breeding in Canada.
Griffith Buck was one of the few people who took an agronomist’s approach, casting his net widely and letting field selection find the best combinations in his early work. van Fleet was another. If you go through early Rose Annuals, he had dozens of interesting, once-blooming types from a fairly wide range of species and many of the H.P. and other advanced classes. Unfortunately those all went by the wayside after his death. Same goes for Schoener and his efforts, except Arillaga.
David Fairchild, a KS native, wrote a book on the origins of the USDA plan introduction office, and the Arnold Arboretum has described some of the introduction process in one of their serial publications- Arnoldia.
If something was an understock it was likely a seedling as is still the custom in Europe. Before 1920 there were few restrictions in importation and so lots of grafted plants were directly imported from growers over there, limited by $$. So canina types are undoubtedly multiple. The use of multiflora for “living fences” in the eastern U.S. certainly spread around a lot of stuff. But whether the seedlings were grown from seed collected in Japan, or just by amplification of what was already here, I don’t know.
Austrian Copper is nearly all one clone in its place of origin, so it matters little how often it was introduced. The same would presumably be true of the “stud” Chinas which were undoubtedly single events at some point in Chinese history.
The A.C., I only know from a paper last year. There is a clone in Holland or Belgium, I forget which, that may be slightly different, but the DNA of most all accessions turned out the same all over Iran. I think this was on the forum or in newsletter last year.
I don’t mean that all the old introduced Chinas are necessarily the same, just that each named one is a single event, and they might all derive from a single early event followed by crossing and selection in China, before Europeans got there. So the genetic base could be very narrow.
Early this year there was discussion of the white prairie rose, which is mostly white where it exists (TX, AK, OK) but the one in commerce is a rare pink selection (R. foliolosa), from a very small area in TX, according to Walter Lewis who is the authority on these roses.
I think provenance is very important and concur with the statement about the variations within a species population in a given field. I’ve often wondered if, when using a proven “species”, one is actually using a proven plant.
I don’t think the importance of provenances applies only to the level of species, but would argue provenance of clones might also be of some importance. Genetic material changes over time. As frequently as visible sports occur on plants, I should imagine that there are mutations which are less evident, but which could affect a plants performance. (Of course, grafting too can introduce viruses and, potentially, genetic variance into a stock, and for that reason as well, provenance is important.)
But then again, I’ve never really been clear on whether a sport, as a parent, would necessarily offer a different brew of prospective genetic material… As some sports reverse freely enough, I rather question their relevance to the breeder… When a phenotype changes, does it imply the genotype has changed?
(Sorry if these are dumb questions – I know only enough biology to confuse issues, and not enough to clarify.)
On sports it depends on which layer the sport occurs in. If the sport occurs only in the outermost layer of plant tissue it will not be passed along the genetic material that is passed along will be the same as that of the original clone. If the sport occurs down to the third level it will effect the genetic material. Of course how knows how many sports go through all the layers that have built up over the years in some of these clones. Some of these clones are quite old. most mutations either have no effect or a negative affect on the original organisms. Few in general cause a distinct natural advantage.
Virus can be a concern because they can be passed on. Also they can cut and paste genes from the organisms they affect. Certain viruses are used to create some of the GMOs out there.
It is defiantly important in my thinking anyway to get the best clone of any species that one wishes to work with. I think it is important for use to know which species we have a good chance to have several options on and which one we do not. Plus one clone could be better for someones program while another one might work out for another persons better.
It does worry me that when several hybrids are said to be related to some species that the whole group tends to be related to the same clone.
Yes, exactly. I am always curious as to what comes out of a sport when used in breeding because I am looking to see if the sport itself is a superficial or deep mutation.
For example, the Cl. Tropicana Williams used to created Orange Velvet passed on the climbing genetics very well. Granted, the canes are 2-3" thick and non-pliable but they are very much climbing canes. Thornless blackberries, on the other hand, do not pass on their thornless mutation sexually. The only ones in commerce are from mutations found on already existing cultivars. The mutation is superficial.
