European hybrid fruit: Sharafuga, peach x plum x apricot hybrid

[Justin]

@GrapeNut

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 would argue that the bolded part refutes your point, since my point which you bolded stated:

@Justin

did do the work to create a great population of fruit trees that could then be planted by anyone around the world in the right climate

Perhaps I should have been more specific - when I said ‘planted’, I meant planting the seeds.

Also:

1. A major point of mine is the adaptability of a landrace. Our climate is now highly unstable.
2. I still think you are in fact correct that it has been done already, since we do in fact have landraces propagated by seed, such as those I mentioned in Ladakh, and it sounds like @tbg9b 's trees were also derived from a seed propagated landrace or landraces, from the sound of the relative stability of phenotype.
3. While there are evidently already existing landraces, there is great value in combining various landraces within a species, or even crossing species, to form new landraces. The resulting increase of genetic diversity can greatly accelerate adaptation to a new area or farming method. Also, maintaining a higher genetic variation can keep the population more adaptive to our rapidly changing climate.

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:

Nourishing Biodiversity - an interview with Salvatore Ceccarelli e Stefania Grando

@GrapeNut

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.

Ah thanks. I was really wanting to know about Prunus, but perhaps it is similar.

@GrapeNut

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?

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’

@GrapeNut

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.

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.

@GrapeNut

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. 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.

@GrapeNut

Yes, but it’s much easier to stabilize an annual plant than a perennial.

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.

@GrapeNut

Delicious? Maybe. Edible? Yes. Good enough for the purposes of obtaining calories without being thoroughly disgusted by your food? Probably.

Is that your direct experience? Because it seems to directly conflict with @tbg9b 's direct experience.

@GrapeNut

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.

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.

@GrapeNut

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.

Interesting, thanks for sharing.

@GrapeNut

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…

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.

@GrapeNut

@Justin

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

The key part of the text you quoted is low genetic diversity.

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.

@GrapeNut

@Justin

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.

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.

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.

@a_Vivaldi

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.

Thanks. So I guess you save a year or two by grafting.

@a_Vivaldi

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.

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!

@a_Vivaldi

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.”

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’.

@a_Vivaldi

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?

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.

@a_Vivaldi

Why add the step that can take longer than you live and might just ruin your whole population through inbreeding depression?

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_Vivaldi

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.

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.

@a_Vivaldi

It’s not for convivence, because establishing a landrace of fruit trees is kinda a lot of work.

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.