Well yes, but that’s not what Justin was talking about. I agree that grafting is a very helpful and powerful tool that should be used whenever it is appropriate.
Also, it depends on the species. A lot of plants depend only on the size and age of the scion, not the rootstock.
I do think there is merit in using humans in a general sense to discuss genetics… It’s just not a direct comparison.
The physical expression of human genetics (phenotype) to us seems large, as mentioned about height. In fact human diversity is extremely narrow due to a population bottleneck a little less than a million years ago. We over exaggerate the differences between us (unfortunately).
Each animal and plant has its own history and that directly results in the genetic diversity it has today. That diversity lies in it’s natural distribution and age as well as human intervention.
The genetic diversity of each type fruit tree (apple, apricot, plum, etc.) is unique. Some are more diverse than others. Humans have selectively bred much of that diversity out of the population of long domesticated plants (and domesticated animals).
All that being said, once we find or actively develop the traits that we want we then clone to preserve those traits. Vigor, cold or heat tolerance, humidity tolerance, bloom dates, harvest dates, pest and disease resistance, tree anchorage, alkaline / acid / salt tolerance. Productive longevity, years to bear, non-biannual tendencies. On and on and on.
Fruit size and taste may be independent of most of those desired traits we are looking for…or can be tied to some of those traits as well.
Genetics is certainly unbelievably complex and science is just starting to figure a small part of it out.
There are plenty of publications looking at certain plants that discuss some of these topics.
A quick search found a nice one in watermelons.
To be honest, the only reason I jumped in on this conversation was because of the many belittling remarks made towards @Justin. Most of the developments in European fruit strains is of little interest to me, as I will likely be dead before these new varieties are ever available to home growers in North America.
Absolutely true point on excellent rootstock choices available for most any soil condition and compatibility to what you want to grow. I only used my seedling rootstock for myself or free giveaways to friends. I would never use them for something that has to be reliable, such as an orchard. I’m amazed at some of the great existing rootstock choices, especially in Europe! 
Thank you so much for sharing from your experience. To me this implies that it was common for the growers of those varieties to grow them from seed. And since you are growing them in a different location and with specific needs, it sounds like growing from seed has worked very well for you, since you can adapt your population to those requirements, including tree size as you mentioned. This is a great demonstration of the benefits of growing from seed versus grafting.
Yes, this is precisely why I was asking for experiential reports, rather than taking Jose’s theoretical explanation devoid of any mention of experience, on faith. I am glad I persisted, rather than be put off by his assumptions and hostility!
Also, it seems that the European plum is itself an interspecial hybrid. Here’s a quote from the paper ‘Genetic characterization of worldwide Prunus domestica (plum) germplasm using sequence-based genotyping’:
The results agree with P. domestica having originated as an interspecific hybrid of a diploid P. cerasifera and a tetraploid P. spinosa that itself may have been an interspecific hybrid of P. cerasifera and an unknown Eurasian plum species. The low genetic diversity and lack of true wild-types coupled with the known cultivation history of Eurasian plums imply that P. domestica may have been a product of inter-specific cross breeding and artificial selection by early agrarian Eurasian societies.
Therefore, it would seem from the evidence that it is indeed quite possible to create phenotypically relatively stable and delicious interbreeding prunus landraces from interspecial hybrids, which was what all of my questioning was after all focused upon. Of course, it can take time to do so, but we already have delicious largely outcrossing interspecial tomato populations - Joseph Lofthouse made such an outcrossing project and had great tasting fruits in some plants in the F3 generation, and now just a few years on has multiple lines some of which are consistently delicious, many people would consider much more delicious than regular heirloom tomatoes (indeed he has had such reports from professional chefs). I grew some SI plants from that project this year and they indeed beat all of my heirlooms for flavour. And this is not S. lycopersicum crossed with edible wild species such as S. cheesmaniae or S. pimpinellifolium - this is crossed with the inedible SI species S. pennellii and S. habrochaites. So, theoretically, it might not take many generations also, to create reliable delicious interspecial prunus populations especially when starting from delicious parent species.
One thing I have been wondering - what varieties were used for those interspecial crosses mentioned in this post? Because, I notice that the European plum Prunus domestica seems to be hexaploid, whereas the Asian (‘Japanese’) plum Prunus salicina seems to be diploid. And peaches and apricots seem to be generally diploid. Was it Prunus salicina used in the hybrids?
Thank you for your analogies. And yes, I do understand why grafting is so appealing, and I am by no means trying to persuade anyone to abandon that method! I acknowledge it as a fine and eminently useful method. However, I will now offer some counters to your point, arguing for the benefits of not using grafting.
Suppose there is a wonderful variety of plum that does great in one environment, but someone wants to grow it in a different environment. It might fail, due to disease pressures, flowering time, or a multitude of other reasons. It might be like cloning the greatest long distance runner in the world but giving him the task of racing the 100 metre race and a crochet competition, then doing a brail speed reading test. Having a cross pollinating population that has reliably delicious fruit but sufficient genetic diversity, would be highly likely to be a better choice, given only those 2 choices.
Someone might say well, why not just chose a clone that is already adapted to your environment? And there are multiple reasons why that might not be the best choice, including if you are in a region for which there is no suitably adapted clonal population; and for the reason that the climate is rapidly changing, both in terms of climatic factors such as heat and rainfall, and in terms of disease and insect populations and so on. And that’s not even to mention diverse microclimates within a region, and differences in farmers’ habits, all of which a genetically diverse population are far better suited to adapting to.
There are diseases which can be passed on through clones. For example, there are viruses that affect potatoes, garlic, and onions, and it seems these problems can usually be overcome by growing them from seed, which is unusual, but highly successful and easy to do. Yes, corporations with vast resources can also use tissue culture to get around these problems, but, I personally value a more democratised approach which is accessible to the masses. And I am not alone in that. I also think that such methods are likely to become more important in future in the face of radical climate change, since there seems some realistic possibility that there will be some form of societal collapse.
There is no need to “wait around for centuries and make billions of crosses in the hopes of eventually getting one Edwin Hubble” if you do not need Edwin Hubble. Let’s take the dehybridising of tomatoes as an example, as I have done above. It seems to me that clonal propagation of modern Prunus varieties is akin to F1s. Well maybe F2s or whatever, but basically, it seems that people are presumably making crosses and instead of waiting for a relatively stable landrace, they are taking a single unstable individual which they like, and perpetuating that via cloning. With tomatoes, this is done by having stable parent lines and continually producing F1 seeds, which are all the same. You can’t grow the same thing from the seeds grown from their plants, because the F2 will all be different. But, many people have grown out F1 hybrids and produced very good stable varieties from them, even though different from the original F1. One such example has been the late blight project I mentioned, where they have kept the strong late blight resistance but by F4 got much earlier fruiting plants, and some with significantly larger fruit. This in my opinion is much better than the quest of copying the clone - the result is better. And one can get many such better results, quite unexpectedly. But anyway, for many people, even if one were to make a fruit tree landrace that was not ‘the best’ taste but was still delicious and adaptive, that would be a significant advantage over a ‘best tasting’ unstable clone.
I do understand that the landrace model is uncommon in modern society. But I hope that even if you do not want to use this method yourself, you at least see its value. Though of course if you do not see value in it, I am also ok with that.
That reminds me of my question I asked previously - do you perhaps know the answer? I will quote myself to save typing it again:
Because your parents are not ‘stable varieties’? (Also because IQ is not merely genetically inherited, and your height might even be a a side effect of eating modern industrial meat from animals injected with hormones 
)
At least they will have served him well for that time, and their children or grandchildren and wider local community could reap the benefits of the next selection, the landrace improved by continuing propagation by seed from those valuable survivors continuing to cross. If several people in the same area were doing this, you could also keep the genepool wider by crossing all the best survivors and make an excellent local landrace, which could be very sustainable.
Edit: Just realised I might have misunderstood something there - when you said ‘dwarf trees’ I thought you were referring to “Several of the naturally growing prune plums were far smaller trees that were easy to harvest from because they were only 6-8 feet tall” but I just realised that was you who said that! So I guess that’s not what you meant, sorry. I meant that if desirably smaller trees came from seed, it might not be the end of the world if some didn’t live long. But I’m now guessing you may be referring to a modern clonal variety? Yeah I would be more willing to accept such deficiencies from seed since pros and cons are just part of the journey. But not from a clone, since it isn’t even on the journey to a landrace!
Hey wow, that’s a great idea! I would guess that that might not work so well for finding disease resistance (does disease resistance get passed from the rootstock?) but that sounds a brilliant way of speeding up fruit phenotype selection. So you could grow seedlings, graft so many onto a few trees, select for the good fruits, cross them all with each other, repeat, and when you have a reliable fruit quality, only then plant many out in a large field for example, and assess for general vigor, disease resistance and so on over the coming years. What a great idea for how to speed up the creation of a new landrace! That sounds like a wonderful way of using grafting to overcome the need for grafting.
Yes I was reading as I quoted above, that the European plum has very low genetic diversity. It seems that despite (it would seem widespread?) propagation from seed, the initial population came from very few parents, back when it was hybridised from those different species I mentioned above. I wonder if Japanese plums might be a better one for making a landrace population from, if they have more genetic diversity - I’m not sure if they do or not but being diploid, I am guessing they might have more. But that’s why I was also interested in the landrace potential for these interspecific hybrids, due to genetic diversity.
Thanks buddy! And your point about using grafting for accelerating breeding was excellent, really appreciate that!
Prunus domestica is indeed very difficult to breed into other prunus. Luther Burbank and Niels Hansen, both prolific breeders, said it would rarely cross and if it did- the seedlings were runted and short lived. 
@tbg9b Appoligies, since you might be reading or already have read my last comment, please not I edited it now, here:
I would argue that the bolded part has already been done, if we’re talking about the major domesticated fruit trees of the world. Look at the diversity of apple cultivars we have. In almost any climate, even those pretty much as far away from that of the Tian Shan mountains you can get, you can find an apple cultivar or two that will do great in your climate. No, you can’t propagate them by seed, but grafting has been around for thousands of years.
I can stick a cutting of a rootstock grape in the ground in fall, let it grow until the following fall, bud a cultivar onto it, and have a few bunches of fruit the next year. Growing from seed, it would take maybe 4-5 years to get the first fruit. That’s if it doesn’t die from phylloxera first.
Again, we have enormous amounts genetic and phenotypic variation existing in major fruit crops. I guess my question for you is why reinvent the wheel? People all over the world have spent generations selecting and evaluating these crops already. Now that we are connected in a way that our ancestors couldn’t even dream of, it’s possible to evaluate hundreds of cultivars from all over the world.
Hybrid vigor, as far as I understand it, is usually due to increased heterozygosity, but why that makes a difference hasn’t been explained. But yes, its increased heterozygosity relative to the mostly homozygous parents, generally in a species that is already fairly homozygous.
Yes, but it’s much easier to stabilize an annual plant than a perennial. Even then you can have issues depending on the species. Where I lived in Davis, you can often see fields of sunflowers grown for hybrid F1 seed production with alternating strips of the seed and pollen parents, which are both homozygous lines. And the difference in vigor between those and a typical hybrid sunflower is pretty striking.
Delicious? Maybe. Edible? Yes. Good enough for the purposes of obtaining calories without being thoroughly disgusted by your food? Probably.
With largely self fertile European plums, your chances of getting something similar to the parents is probably pretty good. For outcrossing, more recently domesticated, more genetically diverse Japanese plums, the chances are lower.
Grapes aren’t the most aromatic fruit so differences in chemistry are harder to pick out (having tasted strawberry breeding outcomes, the differences there can be striking). Even then, it’s easy to have a flavor compound that is pleasant in the parents be found at levels in the progeny that taste unbalanced or unpleasant.
Fruit size is complex and governed by multiple genes in most fruits. Generally that means that offspring will be on a bell-curve with the range between the two parents. The trait can be transgressive though. Also, there are several ways of arriving at larger fruits, and I assume each one is inherited differently. You can increase size by increasing the number of cells, multiplying and fusing the carpels, increasing the response to phytohormones produced by the seeds, etc. I would guess most of these traits are quantitatively inherited, but it’s possible some fruits have a dominant mutation for one aspect of fruit size.
Peaches are mostly self-compatible in the wild and consequently have lower genetic diversity, especially in the cultivars that made it out of China. So I would expect you to have a fairly good chance of obtaining decent fruit. Plumcots and plums of East Asian ancestry have a lot more genetic diversity.
With European plums, not only are they partially or entirely self fertile, they are also hexaploid. So recessive deleterious alleles that will negatively affect plant health have less impact, and it would be harder to affect fruit quality as well…
The key part of the text you quoted is low genetic diversity.
The flip side is that there is a higher chance you have deleterious alleles. Those have mostly been lost in European plums (I’m guessing). In a highly outcrossing (at least originally before domestication) species like grapes, planting out self-pollinated seeds gets you mostly runts. Even in grape breeding programs, it’s difficult to introgress traits like disease resistance from wild species because you cannot cross back to the original parents, not for many generations.
It depends on species, variety, and growing conditions. With some citrus in places with long growing seasons, for example, having fruit the year after grafting is not unimaginable. But someone growing American persimmons at the northern edge of their hardiness limits might have to wait quite a while for fruit (though not nearly as long as from seed in those same conditions). For plums specifically, I don’t know. I think most nursery stock is sold at two years old and fruits the following year, but I could be wrong.
To your broader argument about landraces vs grafted clones:
Realistically, the reason we often (but not always, and commercially probably not even the majority of the times) use landraces for vegetables and grafted clones for fruits is first and foremost about the timescales involved, and everything else is a distance second. Vegetables are so short lived that it is rarely worth the effort to clone and graft them. Fruit trees are so long lived and take so darn long to fruit it is rarely wroth the effort to grow them from seed. Heck, even some plants take too long even when grafted: the biggest commercial impediment on pecan producers is how gosh darn long it takes to get your money back, hence why pecans, despite how awesome they taste, are not commonly grown outside of the southern US.
So that’s just the realistic, pragmatic argument.
If we were to get into a theoretical discussion on landraces vs grafted clones, we’d need to work out a lot of pretty thorny issues, since we’d want to really pin down the meaning of things like “adaptable,” and “true from seed.” But, even before that discussion, there’s one other question that looms large: why bother with going through the herculean task of trying to get certain traits stabilized through decades or centuries of in-breeding, when you can just have a curated population with sufficient genetic diversity and more importantly lots of the genes that are actually worth having and clone from it the varieties that express the traits you want? Why add the step that can take longer than you live and might just ruin your whole population through inbreeding depression? It’s not adaptability, because a landrace is going to be far more genetically uniform and less diverse than the highly unstable population of crossbreeds that modern breeders are pulling their clones from. It’s not for stability, because a clone is far more genetically stable than any landrace. It’s not for convivence, because establishing a landrace of fruit trees is kinda a lot of work. So, why do it?
The only reason I can think of would be some sort of ideological notion that having some locally breeding population is somehow superior because it’s more “natural.”
Just to be clear this is exactly what I was referring to when I said seedlings were of good quality. I know that seedlings of apples, pears, and many other species rarely breed true to type.
I am not the only one on the forum that has seen good quality seedlings spring up from Euro prune plum stock. I would in no way claim this is commonplace with most other, species/varieties of fruit. Atypicaly, Euro prune plum stock seems to have a decently large chance of seedlings breeding fairly true to the parent stock.
I am not by any means advocating for anyone to try and start an entire orchard from seed. I use dwarf rootstocks on the section of land around my home that has limited space and plenty of water. On the section of land I own with far more room I grow the trees on full size vigorous rootstocks. On this section of property I have plenty of room, but water is not as available. The larger trees also keep the fruit branches away from the deer in this unfenced section of property. To me it makes more sense to grow full size trees in this location. I’m sure my kids will thank me for it when I’m gone. You know what they say, plant pears for your heirs.
100% this.
Also, as tbg9b and randyks’ experiences have shown, the inherent difficulties and feasibility of a sexually propagated landrace are species-specific. A peach, apricot, or European plum landrace is doable and has been done. If you’re mostly interested in cider apples, you can grow apples from seed. With citrus, there’s no predicting what you’ll get, or so I have read, not including seeds resulting from apomixis. With grapes, unless you emasculate and hand pollinate every single flower, the majority of your seedlings won’t survive past the seedling stage and those that do will lack vigor.
I don’t envy the scientists trying to breed citrus greening resistance into oranges.
I would argue that the bolded part refutes your point, since my point which you bolded stated:
Perhaps I should have been more specific - when I said ‘planted’, I meant planting the seeds.
Also:
This is a very different kind of crop, but it’s a great example showing the value of combining landraces for creating a highly adaptive crop. You might enjoy this video, an interview with Salvatore Ceccarelli and Stefania Grando on evolutionary plant breeding in the context of wheat. Skip to 2:50 if you want to go straight to the interview:
Ah thanks. I was really wanting to know about Prunus, but perhaps it is similar.
There is a great difference in genetic variation in the world of clones, and genetic variation within an interbreeding population. The latter results in an adaptive population, whereas the former does not. Also, it’s not reinventing the wheel - the landrace method is as old as agriculture itself. And still being used in many cultures around the world. Furthermore, I have detailed numerous benefits in my comments above, which might answer your question as to why.
Also just to give you a plum example:
Besides, most planted plum orchards in other extensive production regions of Argentina derive from a few introduced cultivars of global distribution.
By contrast, European immigrant growers early in the last century who settled in the Paraná River Delta (PRD) introduced old traditional cultivars from their European countries. They selected wild plants emerged by the spontaneous sowing of seeds of the introduced varieties that they cultivated based on good performance and high-quality traits. Growers from the PRD had to face a particularly harsh environmental ecosystem.
The PRD is a unique ecosystem dominated by floods because of water discharges mainly from the Paraná River followed by discharges from the Uruguay and Gualeguay rivers. Tidal and storm surges from the Río de la Plata estuary as well as local rainfalls also contribute to generate these wetlands [3]. Precipitations in this region are influenced by the El Niño Southern Oscillation (ENSO) [4]. Indeed, three important floods associated with El Niño took place in PRD in 1982, 1998, and 2007 [3,5]. Furthermore, the alternation of wet and dry periods in the PRD influences the variability of the ecosystem. All these features give place to at least 15 landscape units [3] with a high ecological diversity distinctly adapted to annual hydrological cycles [6].
In this climate context, growers from the PRD generated local plum landraces that were cultivated after multiplication by grafting or from seeds, and therefore obtained the best wetland-adapted plants. In this way, they intuitively created a specific fruit tree germplasm for fruit production in an ecosystem with harsh environmental conditions that alternates river flooding periods with extreme dry season. The generated germplasm, which presents different harvest times (November to February, Table 1), is highly variable regarding pulp and skin coloration, as well as in its organoleptic characteristics.
Thus, Japanese plum landraces selected in the PRD are a unique genetic resource in the world, and one of the few adapted to delta edaphic conditions and to humid temperate climate [7]. These landraces could constitute the closest reservoirs of “useful” alleles for future genetic improvement in the context of climate change. They contain the genetic variants naturally or artificially selected by growers because of their adaptation, productivity, or resistance to different stresses in the territory.
Source: ‘Characterization of Genetic Diversity in Accessions of Prunus salicina Lindl: Keeping Fruit Flesh Color Ideotype While Adapting to Water Stressed Environments’
Well please for a moment think of this - we are so connected today that it is easier than ever (if we overlook the rapid and continuing loss of many landraces around the world) to bring landraces together to make excellent genetically diverse new landraces, which can help greatly in extending the range of a species, or in facing new climate and disease pressures. This is one of the most important things about genebanks, for example. If you have the time to watch the video I shared above, this might help convey some of those benefits I am talking about of this kind of method.
Yes. And sustaining genetically diverse landraces is a great way of maintaining that heterozygosity. Again, this is one of the advantages of growing genetically diverse landraces, and also connected to my own project of creating an SI tomato landrace. Though this can also be avoided to some extent in an SC population if the flower structure gives a sufficient rate of outcrossing. And this is rather common in wild SC tomato species, many (or most?) populations still having exserted stigmas, which would result in a more adaptive population than the very low outcrossing rate of most domestic tomatoes, which generally have inserted stigmas, possibly caused by domestic pressures such as being grown in very small populations over many generations.
Yes, of course, as I have acknowledged. Though I have also shared how individuals and communities need not stabilise to the same degree as are required in the common capitalist model, so the time required, whilst obviously being more than for annual plants, may be considerably less than it would be for professional breeders breeding for modern commerce.
Is that your direct experience? Because it seems to directly conflict with @tbg9b 's direct experience.
Ah, I had been wondering about that - I read in one academic paper that “European plums are variable between self-incompatibility and self-compatibility” but cold not find the relative rates. I read also on michiganplum.com “Most European plum varieties require cross-pollination from another European plum tree variety.” But perhaps it would be safer to try to landrace Japanese plums, to make sure they’re SI, especially if my guess of them being more genetically diverse as a species, is correct. I’d also be really interested to know if they are or have been until recently, grow as landraces in some areas rather than by grafting. I think it should likely be a better idea to start a new landrace project by gathering old landraces together, rather than starting from modern clonal varieties of Japanese plum. I would expect that would give faster results in terms of reliable deliciousness.
Also, are you saying the Japanese plum, i.e. Prunus salicina, was domesticated more recently than P. domestica? I have searched and cannot find an estimated time for when it was first domesticated but it seems at least thousands of years ago, in South China.
Interesting, thanks for sharing.
I would assume that in SI landraces maintained via seed propagation, there would be a lower change of finding deleterious alleles in the population compared to clonal populations, since they would be selected against. This is another reason why I would assume it is better to start with established landrace seeds/plants if one wishes to continue a population via seed, or create a new landrace.
Well, if you would start a landrace from the offspring from a single interspecial F1 cross, then that would presumably be the same or lower in genetic diversity that that example you are referring to.
I don’t know about grapes so it’s hard for me to comment. But, I would guess that if there are populations that are now or were until recently, propagated by seed, then the risk should be minimal, no? I understand that that would however be a danger in clonal populations that are not coming from reliably delicious seed propagated populations.
Thanks. So I guess you save a year or two by grafting.
Yes, indeed. Commercially it would not make sense. Socially, it would take dedication and best done with community effort. There are such landrace tree projects I have come across. I think it might even be useful to combine it with selling timber! 
Well just to deal with that briefly - by adaptable I am referring to genetic adaptation, which requires sexual reproduction (aside from more minor epigenetic changes). And I was focusing on relatively stable phenotype in terms of reliable deliciousness, rather than a stricter idea of ‘stable’ in terms of identical fruit etc. One could think of it in terms of ‘good enough to delight a community’, as opposed to ‘homogenous enough to be sold in corporate supermarkets’.
I feel as if I have answered that many times already. To reiterate, primarily: to be adapted to specific conditions; and to continue to adapted to changing conditions.
Because I care about future generations? Also I do not think inbreeding depression has to be a problem. If someone didn’t have enough space for sufficient population size on their land, it’s still possible to do it collaboratively. And there are such collaborative tree breeding projects going on - the ones I heard of might have been nut trees, I forget now. But anyway, that doesn;t have to be an issue.
A population of clones is not adaptable at all. The only adaptation that can take place is the farmer choosing to replace trees with other clones, isn’t it? That seems like saying a car with no wheels is more mobile than a car with wheels, because you can use a crane to pick the car with no wheels up and move it somewhere. Genetically diverse outcrossing populations are definitively adaptive, clones are not, right? I don’t understand where you’re coming from disagreeing with that. I mean, I do agree with you that the population the breeder has, is diverse, so, so long as you depend on that person, you can buy new genetics. But I am talking about a democratised, sustainable approach which is not reliant on our current easy access to the commercial products of professional breeders. Personally I value natural adaptability. And this also means more choice, in some respects. Just to take tomatoes as an example again - not many tomatoes are bred for low input organic farming, for example, nor for my specific climate. Crossing with wild species and making new landraces is a fast way to adapt delicious food to my specific area and growing methods. So, it’s lucky that I’m working on that, since I don’t think I know anyone else who is! Well, maybe 1 or two of my friends in similar climates and with similar growing styles, so I am glad to collaborate with them. But, you get the idea I hope. I do however think that many people would love to grow the results, if we succeed well enough. As it is now, outdoor tomato growing here is extremely prone to blight, coupled by the need for earliness. And the only good blight resistant varieties available are more expensive than most people want to pay for, and generally deficient in taste! Many other crops are dependent on toxic chemicals, and seed companies have little incentive to breed for environmentally friendly growing methods. Anyway these are among the reasons why it is not always pleasing enough to rely on commercial breeders. I have mentioned some other reasons above.
You confuse the short term with the long term. It would be very convenient for example, to have delicious disease resistance OP tomatoes for this climate. It is very inconvenient for me to breed them. Yet when I do the maths, some years of personal inconvenience to me seems insignificant compared to the great convenience so many others could derive for so many years to come, from the fruits of my labour.
Oh, sorry I just realised you said ‘convivence’ not ‘convenience’. I cannot find that word in my dictionary. Perhaps my interpretation of your statement was correct? If not please explain.
My bad, twas a typo.
Sounds like we are going to have the much harder conversation of pinning down our terms and seeing things through to the end. This might not be the place to have that discussion though. Probably best to create a separate thread.
In casual terms even by nurseries and universities who should know better, “salicina” is lumping quite a few diploid plum-type species under the same banner. True salicina, americana, cerasifera, maritima, besseyi, simoni, cordata, nigra, pumila and others have been used in the parentage of modern “salicina” plums.
On a different note, Mr. Burbank used to encourage people to plant the seeds of any locally grown fruit tree that was exceptional. 
I do wish people did that sort of thing more. Despite my harping against the practicality and efficacy of fruit tree landraces, I’d maintain there is palpable benefit in people growing out some fruit from seed, even if just OP.
That makes sense. It would be interesting to know if @tbg9b 's seed planted trees are SI or SC. But anyway, I would definitely not rule out SI populations. In fact, I would deliberately chose them over SC populations, due to the greater adaptability. Though having said that, if the SC anyway have an acceptable rate of outcrossing, there’s no need to rule them out, and it would after all give the added benefit of folk being able to grow just 1 tree.
It would also be interesting to know if the Ladakhi landrace apricots are SC or SI. And, whether or not there are or have been seed propagated populations of Prunus salicina - if there are, that would seem a great species to start a new plum landrace from. And if there are other species that have been thus propagated which are crossable with P. salicina, that could be a great source for starting an interspecial landrace project.
Funnily enough I heard of someone breeding citrus (I forget if it was lemons or what…) way beyond its natural range, by continually planting … maybe it was thousands of seeds… each year. Finally they succeeded. Not sure if they continued via sexual reproduction or grafting, but it anyway sounded like a cool project.
When I used the term, I was referring specifically to the species domesticated in Southern China, which also spread to Japan; not to the American hybrids.
Sounds like a cool dude!
Hey I’m glad to hear you saying that too!
I’m going to create a new topic for this discussion, because it’s been like 50 comments since anyone mentioned anything about Sharafuga.
@a_Vivaldi I don’t know if you have the power to do so, but if you want to move the whole of the discussion I initiated over to a different thread, you’re welcome to do so. I suppose you could call it something like ‘On the question of creating a new Prunus landrace’?
Hello Jose, as a Ukrainian, thank you very much for your support, political correctness and clear position on this issue! Actually, there was some misunderstanding there, so I want to clarify that Globus was produced at the research station in city Krymsk which sounds very similar but is not located on the Ukrainian Crimean peninsula, but in the Krasnodar region of russia which located not far from Crimea. So, Globus is indeed a russian variety.
Sharafuga (which is also called here as Nectacotum) is definitely not a Globus variety, since i have both. It is probably one of the varieties of Zeiger (it’s not 100%,
but if it is true, it is not known which one exactly and definitely not from the widely known ones). The same fate also applies to a newer (and, as for me, more interesting) variety, which is here called just as Nectarine Pruim (or Nectaprium).
Welcome to the form Viktor, and thank you for the information about Krymsk, Globus, and Sharafuga! I hope you enjoy the site.