Breeding New Fruit Tree Landraces

It might be a “variety” definition you’re going for, Justin. Modern breeding for stable, seed-born, similar individuals. “Hansen’s Bush Cherry” comes to mind, Mr Hansen bred prunus besseyi by the 10,000’s discarding unwanted traits each generation until he could release the stable , genetically similar line he named the “Hansen’s Bush Cherry” variety.
And I could easily be wrong, been over 50 years since I was in school for the subject! :blush:


Well I personally feel that I am using the term in conformity with the way it is used in the many academic papers I have read on the subject. Admittedly, my reading is biased towards rice, potatoes, and a few other crops. So who knows, perhaps there are different crops (or animals) for which scholars tend to have a somewhat different usage of the word. But what I would say is that words’ meaning is dependent on their usage. For example, nobody (I know of anyway) says ‘gay’ doesn’t mean ‘homosexual’, because in some contexts it means ‘happy’. The word has meaning by the way the word is used. And I feel as if I have provided ample evidence for the usage of the word from many sources in botanical academia to support the way I am using it. By which I mean to say, if my use is in conformity with its already widespread usage at least in those circles I referenced, there might not be any need to ‘broaden’ it. If it is already sufficiently broad. Don’t you agree that I refuted some of your points quite satisfactorily?

So then what is your cutoff point? Exactly how many years has to pass before it qualifies for your criteria? And I ask that seriously, because without quantifying that, it’s kind of like saying nothing, right? Like, it’s not as though the 13,192 identified Laotian rice landraces all come from the ancient past - they are constantly making new ones! So if you are going to insist on a time requirement, then we should be open about what exactly that time requirement is.

What’s that meant to mean, ‘formal crop improvement’? Improving crops is very much a concern to traditional farmers. I can bet you that countless landraces have come into being because the farmer saw something in the plants that they considered an improvement, and consciously selected for that and made a new population on that basis. Let’s look again at that paper ‘Naming of traditional rice varieties by farmers in the Lao PDR’:

Some names indicate higher yield potential (broken store Lav tek, heavy grain Phannak, twelve grains yield one million Moon lan). Farmers use names like Gnod nang (superwoman) and Gna thao (grandmother) to indicate high yielding varieties.

I mean, it should be really obvious that farmers select for improvements. But to give concrete examples, those landrace names make it quite explicit that yield was one such criteria that they were specifically interested in, and named new landraces after. And I know of examples from India that were selected for their beauty - beauty which is only seen by the farmer and not even there in the final product, the naked grain - which most modern breeders would not be interested in since it doesn’t fit the capitalist model, but for sure some traditional farmers will be interested in beautiful grains in the fields and consider such things as ‘improvements’ even if a cold economist would not.

To give another example from that paper:

Good grain quality and aroma is called by such romantic names as Nang nuan (sweet and soft), or Hom nang nuan (sweet smelling soft lady).

These things are not random. They’re deliberately selecting for ‘improvements’. Here are some more examples:

Lao farmers have selected varieties that have resistance to commonly occurring stresses such as drought or flooding. Drought is important in both the rainfed lowlands and uplands. Drought tolerant varieties are called Bo ngo nam (does not care for water), Khok (upper terrace), Ea phon or phon (ant hill), among many others. Floods are a common occurrence along the Mekong River and its tributaries. Variety names indicate adaptation to flooding: for rapid stem elongation there are names such as Loy loy or Phou (floating or swimming rice), and Loy pa or Louk pa (floating fish). Many of the traditional varieties grow very tall and lodging is a major constraint.Varieties that do not lodge are called by names such as Kok lek (iron stem), Bong (bamboo stem), Aev (flexible stem) and Tia or Tam (short plant) for example. They also indicate adaptation to poor soil conditions, such as Bo hina (any field). Resistance to biotic stress like birds (hidden against birds Li nook), and good competition with weeds (win over weeds Phae nya) are common.

Maybe it’s about the word ‘formal’? Maybe this is not considered ‘formal crop improvement’ because these skilled farmers don’t wear lab coats or suits or write academic papers?

Also this bit about “associated with traditional farming systems” seems totally arbitrary to me. Suppose an expert Laotian farmer moves to France, and develops their own varieties over decades there which qualify as landraces in every respect except that France does not have the tradition of growing rice in the way she’s growing it. So then is it disqualified because she’s not using ‘French’ farming methods? Or, is she passing the criteria because her method is in fact traditional Laotian farming, just that it is in France? If so, what if she isn’t Laotian - a French woman using Laotian methods, is the population then disqualified because the ethnicity of the farmer is what is critical? If so, what if a French person develops a landrace in Laos using Laotian farming, are they disqualified on the single basis that they are French?

Or what if Italians make a new wheat landrace but use a no-dig method, are they disqualified because the well established mainstream Italian method is to use ploughing and toxic chemicals?

Also from that paper ‘Mechanisms Explaining Variety Naming by Farmers and Name Consistency of Rice Varieties in The Gambia’, this part I put in bold is worth remembering:

Millet versus Rice (Outbreeding versus Inbreeding Crops)

While in The Gambia rice varieties are often named after people, millet varieties mostly have ecotype names (Nuijten 2005). This difference is related to the fact that rice varieties are plentiful and are replaced relatively frequently, while millet varieties are few and not often replaced. Because of the small number of available varieties, millet farmers use the ecotype names (which have become part of the language) for naming millet varieties, whereas ecotype names cannot be applied to rice, which has many distinct varieties per ecology.

And I don’t have time to search for the part in one of the above papers about the frequent new creation of rice landraces in Laos, but, my most concise response to this idea of " that has historical origin , distinct identity and lacks formal crop improvement , as well as often being genetically diverse, locally adapted and associated with traditional farming" is that, like I said before, all breeding has a history. And deliberate improvement is a fundamental aspect of the development of new landraces in ‘traditional’ cultures, like the ones I have referenced above.

Also it’s worth noting that many of the landraces in Laos that these eminent rice research organisations define as landraces, are grown in quite varied conditions, like some of them being grown both in upland and lowland conditions, the two contrasting rice cultivation methods. So, as I have clearly demonstrated above, it’s not just that it’s false to think there can only be 1 landrace of a crop in a single bioregion - it’s also the case that one landrace can be grown in multiple quite different bioregions. And while that might seem somewhat contradictory to the idea of landraces being characteristically adapted to specific conditions, it makes sense when we realise that some landraces can of course do very well in a variety of conditions.

No I don’t think so. That’s precisely why I just gave so many references specifically to the academic use of the term ‘landrace’ from various different cultures and countries. I could give more from Andean potato landraces but I feel like I have made my point enough just with rice. I would say ‘variety’ is a broader term than ‘landrace’ and can be applied to landraces, but ‘landrace’ is more specific. Not all varieties are landraces. Also ‘variety’ is more easily understood by the public so sometimes that word might be used instead when referring to landraces. I will quote again from that paper ‘Rice Landrace (Oryza sativa L.) Field Survey and Collection in Xiengkhouang and Houaphan Provinces of Laos in 2014’ to give an example:

Also these are not from random unqualified sources - that was published in the Annual Report on Exploration and Introduction of Plant Genetic Resources.

I would really hope that it’s obvious that with regard to the breeding methods I have been advocating for, I have been talking quite specifically about populations that are quite deliberately genetically diverse. That’s been the very core of my focus throughout this whole discussion.

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Justin, you are missing - deliberately I think - the key part of a landrace. A landrace has been grown in a region long enough to have lost many traits not needed in that region. In other words, it is more fit for growing in the region of origin than other breeds or landraces. What you are breeding is not a landrace.


FYI, “Isolated” need not mean it is the only form of a species available within a certain country. It need only mean that it is reproducing isolated from other forms; at least in so far as to allow it to persist as identifiably distinct from them (it wouldn’t mean that no members of the landrace ever came in contact with other types, but rather this is a generalization of the overall population). Take for example the many ancient types of corn in North America. Different groups maintained different landraces of corn. They couldn’t be attributed to specific breeders, but rather to peoples of differing locations and cultures. These unique differences between landraces would have undoubtedly developed as a result of cultural preferences in combination with environmental pressures. It’s a bit different than a breeder trying to push a population to reach their personal goals.


I would say that’s a generalised observation rather than a rule - would you not? I mean, you say “what you are breeding” - what makes you think what I am personally breeding doesn’t fit that anyway? I have been talking about breeding specifically for one land, but with enough diversity to be able to adapt to the conditions of that land as our climate continues to change, so I don’t know where you are seeing contradiction there in the method I have been advocating for regarding fruit tree projects, nor about my own work on tomatoes. Naturally when you start with a highly diverse populations such as a hybrid swarm made from landraces gathered from around the world, or my interspecies breeding method, then yes as I keep saying, the initial extreme diversity quickly settles down to much less diversity, in that period of rapid adaptation as it transitions from a hybrid swarm towards becoming a landrace - a deliberately fast way of creating a landrace - so there will be a rapid loss of many traits as it adapts to the local conditions and then a further loss of traits when you start selecting for phenotype after or during that process. So I can’t see how you’re saying I missed that, I think I covered that in detail. But, we have the option of how far to take that. Landraces are still adaptive, and we have the choice how far to narrow the diversity, and how limited they are to regions/conditions.

I’ll give you an example from one of the papers I quoted from above, ‘Genetic diversity study in landraces of rice (Oryza sativa L.) by agro-morphological characters and microsatellite DNA markers’ to show how some landraces in this paper are only grown in single conditions whereas some are suited to more varied conditions:

Farmers in Kaski identified four different domains for rice. These were Mule
khet/Kule khet (irrigation by seasonal canal), Sim khet (marshy wet land), Tari khet
(rainfed good fertile land) and Pakho tari (completely rainfed marginal uplands). Kule
khet ranked the first in production potential and followed by Sim khet, Tari khet and
Pakho tari (Rana et al., 2000b). The distribution and diversity of landraces varied greatly
between these domains (Appendix 4.3a, Figure 4.6). Kule khet and Sim khet were the
most favourable domains for rice, and had the greatest diversity of rice. Tari and Pakho
tari were two domains where water was limiting and they were both less productive and
less diverse. Out of the 69 landraces, 38% (26 landraces) were specific to a particular
> domain while 62% were grown in two or more adjacent domains. Jhinuwa, a small grained, aromatic rice, was the only one reported to be grown in three domains: Tari,
Mule khet and Sim khet.
Out of 21
landraces reported in the survey, 13 (62%) were specific to domains while 38% were
grown in adjacent domains (Appendix 4.3b and Figure 4.7).

Also to your point

Let’s think about that. We know for a fact that many landraces for one crop are grown in the same region. I have shown that they’re often grown even in the same field! By your logic then, for all those (which would be many) that originate from the same region, only the single fittest landrace in that region would qualify as being called a landrace, and all the others would be disqualified! But evidently this is absolutely not the case, as demonstrated by the above papers, and countless papers on other crops such as potatoes and so on. So I ask you, where are you getting that idea from? And what is your explanation for that severe contraditions - are you saying all of these botanists and landrace experts and top international organisations are wrong in their use of the term ‘landrace’?

Furthermore, according to your logic, even the most ancient landrace of a region would be disqualified from being called a landrace the moment any local farmer were to come up with a new landrace that were more fit than the old one, or even to import one from elsewhere. I find it hard to believe that that is your view.

For whose information? I can’t tell if you are directing that at me or at @swincher . And I don’t know why you mentions countries - that is an arbitrary political boundary, so I will not focus on that category but anyway to you point… They specifically wrote:

So I agree with you, I’ve demonstrated multiple landraces being traditionally grown even in the same fields, and many landraces per village or farm.

I don’t know about corn, but I would not be surprised if also individual groups or families also grew multiple corn landraces.

Sure. Especially after the genocide. But let’s see that paper ‘Mechanisms Explaining Variety Naming by Farmers and Name Consistency of Rice Varieties in The Gambia’ again:

To study consistency in variety naming, the logical starting point is the character of variety names. Various researchers reported for a range of crops in different parts of the world that farmers name their crop varieties after plant traits or for the person who introduced or first encountered the variety.
From these examples, we conclude that new rice varieties introduced into a village which are adopted by many other farmers of the same village in a short period of time are named after the person who found or brought the rice variety to the village. Naming a variety after the person who introduced it can be perceived as giving credit to that person. After a period of time, maybe 20 years or so, the variety gets a new name based on its distinctive morphological, agronomic, or culinary traits. Possibly, when varieties get more widely diffused, the actual origin loses its meaning and is forgotten.

That’s just one example. But even in cultures were new landraces are not named after the person, the person instead naming it by its traits or some romantic name like some examples I gave from Laos, for a while at least, many people still might be aware of who started it off.

How can you explain traditional farmers deliberately coming up with new landraces by selecting for traits that please them, as we continually see in traditional landrace cultures, if you ban the application of ‘personal goals’ from the equation? Would you really strike from the list of landraces, any that came about because the farmers brought them into being because they fit with their goals for taste, aroma, disease resistance, yield, performance in drought, and so on? I can’t see logic in that.

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So apparently this was indeed about lemons and the story is reported by ‘David the Good’ in his book ‘Push the Zone’. I don’t have the book so was unable to find the name of the person.


A landrace is s landrace. How people use them does not define what a landrace is. Seems use is being used to redefine the meaning.
Looking at the subject of this thread the last thing I would want is a landrace I’m looking for diversity in flavor and ripening times. I want a mix of flavors that ripen throughout the growing season. This is a huge influence in what I breed.
I like growing white, yellow and red fleshed nectarines. The diversity is very appealing. I have a red fleshed nectarine that ripens in august and a red fleshed peach that ripens in
October I would like to cross and back cross to get a red fleshed nectarine that ripens in September. At the least it would be fun trying.
It seems to me the only good reason to stabilize genes in fruit trees would be for use as a rootstock. I know citrus is different. I can’t grow them so have no interest. Even if I could I’m not that interested in citrus which is nothing like the fruit trees I do grow.
What would be the point of a fruit tree landrace? What’s not covered by the multitude of cultivars out there? Seems to me finding a cultivar with desired traits and cloning it would be the way to go. I guess just about every tree nursery does just that. Again the only need for stabilized genes is for rootstock like Lovell peaches you can grow as seed for rootstock.


Well if we take the same approach that dictionaries generally take, then actualy usage defines meaning. Take the article ’ The Oxford English Dictionary, like the English language, is all about change’ from the National Post for example, which states:

Samuel Johnson once said a dictionary should aim to “not form, but register” the language. Indeed, a dictionary should “not teach men how they should think,” he continued, “but relate how they have hitherto expressed their thoughts.”

We tend to think of our dictionaries as tools of instruction; as books that set the standard, with a certain air of the definitive, for how our words ought properly to be used. But that was never the intention. The great lexicographers understood that the ideal campaign of a worthy dictionary was descriptive, not prescriptive. It would simply record what we’ve already agreed upon socially. It would, like the English language, live and breathe and change.

That’s why I have been making my argument against those who are saying I am using the word incorrectly, by refuting their points with direct examples from all of these professional publications showing their use of the term.

It sounds to me like you might therefore not want a landrace that doesn’t have those qualities, but that doesn’t have to mean you would not want to make your own landrace within those parameters. Or if some would consider that ‘too diverse’ to be called a landrace, no problem, let them call it whatever they want but you could still use this method I have been advocating for but calibrate your phenotypic selection process to allow for that variation you want, while still ending up with a population that is specifically well suited to your land.

Or if that would be too unpredictable for you and you might not like the various fruits that are in between the types you specified, various different blends of traits, then you could take the more common landrace approach of making (or acquiring) landraces that individually suit those goals and grow them all on your land, just like rice farmers grow different rice for the different dishes they love to cook etc… Similarly people can grow or create multiple tomato landraces, for example having some cherry tomatoes, some beef tomatoes, some paste tomatoes, some storage tomatoes, and on another variable, earlier and later ones to spread out the harvest.

I’m actually trying to work not just with SI systems but UI systems, so that outcrossing domesticated tomato landraces can be grown in groups neighbouring each other but remain distinct from each other, for example. Though one could also use larger distances to isolate them if they didn’t have inbuilt separation via UI (unilateral incompatibility), like is done with various other SI crops for seed production. I just prefer if they have inbuilt protection from mixing so that it makes things easier for other growers.

I don’t know much about SI and UI systems in fruit trees, but if there are crossable species, this might be possible - for example if fruit tree A can be a pollen donor to fruit tree B but the cross can’t go the other way, it could be possible several BxA crosses, and through selection, breed a population from them that can cross with each other but not receive pollen from B. Such a population would then be possible to grow as an interbreeding population alongside populations of B but still being genetically isolated from them. In my tomato case, that means my BxA tomato population would be protected from dilution from B, B being domestic tomatoes. So far, I have an F1 generation that is behaving exactly like this, so the next step will be to try to select in F2 for that characteristic. If there are a great many that pass that test, I might also select for other traits at the same time, maybe environmental performance and/or fruit characteristics; or if there are too few, I will wait until later generations before doing so, to not prematurely limit the diversity. And in parallel I am working on a different population with a different isolation system being brought over from another wild species, let’s call it BxC (though it’s more like Bx[DxC] since it uses a bridge species) with the hope that that can be lead to a population that is genetically protected both from B populations and from BxA populations, just like A and C are protected from B.

But it also might be the case that none of these options would suit you, and you’d rather grow from grafts or from seed but not have any continually evolving seed-grown population ongoing, adapting to your land, and that would be fine too, of course. In particular, growing multiple highly or totally outcrossing fruit tree landraces in one area which are cross-compatible, would sound like it would only be normally applicable if there were suitable separation distances between populations, so that might rule that out for various people.

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From my vantage point, There are sort of two tracks to this discussion here.

One is just broadly can and should you breed for purposes of producing seedlings as an end in itself- not rootstock, but seedling “varieties”.

The second is the semantics piece- what constitutes a landrace vs variety vs subspecies vs species. That type of analysis can go around and around in large part because words are always fuzzy at the edges of their meaning. We all know there are reptiles, amphibians, and mammals, but damned if there isnt a duck billed platypus to stick in the craw of our otherwise perfect framework.

Heck, as Ive pointed out before, the species concept itself, useful as it is, is still not flushed out and an area of active debate.,-sexually%20re-%20producing%20organisms.

Just as with grammar, there are many “special cases”, and if you poke at them a bit you realize the whole thing is a construct, a useful shorthand. So working backwards from the definition as though it were immutable will never produce totally satisfactory analysis

Not to derail the conversation with a linguistic deep dive, but properly speaking, ALL words are metaphors. Etymology makes that clear. Its only usage that leads to a concept becoming reified as though it were an actual object. We may think those meanings are bounded, but just like zooming in on a cell wall, it turns out theyre permeable.


This seems like a good, reasonable way to approach the issue, and we could probably have a great thread if we focused on the first question instead of the second. But I suspect the next 100 posts will still lean heavily toward arguments over the second part.

I think it is a great idea to create a breeding population where the long-term goal is to allow people to propagate it by seed and usually get the same fruit trees, or something close enough. I’m imagining things like Indian Blood peaches, or Antonovka apples.

The problem with one person trying to do this with fruit trees in their lifetime is even with all the tricks you can concoct to speed up maturation, or even picking the most precocious fruit species you can find, that level of stabilization will simply require too many generations of trees for a single person’s lifespan. You could start with an already stable population and select out a few specific traits, but that’s not really the same thing as creating that stable population from a diverse starting gene pool, which is really the thing that was proposed, I believe.


Yeah, that was after all the real topic. Though I’d add that it was not merely about being seed propagated, but also about being genetically diverse, and both adapted to a land (or on the way to that) and adaptive to further climate change. And the inter-species aspect of the topic was a part of that diversity aspect. The ‘landrace’ label I believe fits quite perfectly to this but those uncomfortable with that term can just use another, like ‘adaptive population’ or whatever.

I’m glad you think so. As mentioned above, from my view, that can be a great aim, and having reliably delicious but still varied fruit can be good too. That can even add a really fun aspect to it. Right now I am imagining several neighbours getting together in excitement to taste the fruits of a tree’s first harvest, or excitedly swapping fruit from their all unique trees. What fun! Maybe even inventing hyper-local food dishes or wines/beers/ciders specific for the fruit of individual trees!

That really depends on what ‘level of stabilisation’ you are aiming for! Though also, how long did you guys say it takes for a graft to bear fruit if made from a seedling? Say it’s 2 years, you could do 8 generations in 16 years. So for example (I have already given this example but I will give it again), you could make a very diverse… ok I will put this in bullet points and I will gear this to a speedy method:

  1. Start with a selection of parents, which you might already have on grafted trees, or you might even use an already distributed collection among a network of friends etc., then cross them all. You could even do this as a community, even an international community if sending pollen by post or transporting it in person.
    These would be faster but the slower option would be to obtain diverse seeds from diverse places, go to step 2.
    And for this step, this could be selecting these many parents all from 1 species, or from different compatible species, or even from already existing interspecies hybrids, though making your own would give you more control, and potentially much more diversity since you could make many different crosses with the same 2 species.
  2. End of season, plant all those seeds, and grow them under good lights in warm conditions, so you might be able to graft them by next spring or whenever the grafting season is.
  3. When those are flowering - would that be that same year, i.e. year 2, or would it be year 3? Let’s suppose it takes another year before flowers, so in year 3, then cross them all, and repeat step 2.
  4. Year 5, you have the double crossed seeds. Lots of them. Repeat step 2.
  5. Year 7, you now have a large very diverse collection of grafts, all unique in the world. It could be hundreds, or more even. Now eliminate all that don’t have acceptable fruit.
  6. With the remaining ones, plant as many seeds as you like, from all of them. You’re now growing them in the ground, so the environmental natural selection will be starting.

You might still get fruits from the next generation that’s not acceptable, but you’ve increased your chances by eliminating those ones you didn’t like. This saves space. And using the grafting method up to this point, as well as indoor seedling growing, has saved time.

  1. If you want to save more space, to rush the project you could also take a cutting from each seedling as soon as they are big enough to do that, and graft them, making it such that you will be able to sample their fruit earlier, so if you want to, for those you don’t like the taste of, you can dig up the rooted plant.
  2. If you want, from those new grafts, for those you especially like, you could even cross them and grow them out, putting them in the spaces made free from eliminating the ones you didn’t like the taste of.
  3. Just keep repeating this cycle. Once they are deliciously stable, you don’t need to do any more grafts, though you might still just out of impatience at wanting to taste each new unique fruit.

It would be better to be as lenient as you can be with the taste tests (and especially so for the first year of tasting), since keeping more diversity will mean better changes of keeping environmental/disease capabilities. And, if one doesn’t quite meet your taste criteria but is already showing some other advantages such as vigour or cold resistance more than the others, you might consider keeping it in no that basis, or you might even deliberately cross it with some delicious ones and plant those seeds, and perhaps even remove that parent, and a couple of years on taste the offspring and they might be worth keeping and have some of that added benefit.

  1. Some stage after step 4, an additional way of speeding things up would be to deliberately expose your entire population to specific diseases you need them to have tolerance to, or environmental tests such as cold. Now, if it were me I would rather do this by cloning them all via cuttings, and using those cuttings once established as the test subjects. You could then remove from your population all of those whose clones failed the worst in such tests.

Of course you could just do it all simply, just make the crosses and plant the seeds and not use grafting at all, but yes, that will take a long time and would probably be a multigenerational project, which can also be great, but if you are in a rush, the above method could dramatically speed things up. You’d just need to keep an eye on the total diversity you are keeping, and if for whatever reason your population diminishes too much (for example if in your haste for specific disease resistance you eliminated a high proportion of your population), you could add new members from new sources and cross them into the population. You might even hear of a wonderful tree that suits your needs, perhaps an old neighbour heard about your project and shows you her tree - so great, add it in, see how that goes. In the first several cycles, this attitude could be quite helpful.

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Your idealism is palpable @Justin. Your ideas bespeak the likelihood that you are in a particular stage of things. Pardon my presumption, but Im guessing you may be in your 20’s, childless, unmarried. You’re considering mass plantings, which would suggest you have access to a piece of land, but if so, you havent owned it long enough to realize how much time and energy it can and will suck up just to keep it in stasis. If you dont yet have land, youve not realized the full extent of the BS and compromises you’ll inevitably go through to attain it.

If true, that doesnt diminish the veracity of your arguments, but I suspect some of the pushback youre getting comes from a place of having lived a little (or a lot!) longer, having less discretionary time, more responsibility, and having had expectations tempered significantly by experience. The older you get, among other things, the less long range you tend to think. Similarly, having a family and a home of ones own tends to temper ones tendency to consider the greater good vs tending to ones own. Both come from similar impulses, theyre just different expressions based on what stage of life youre at and how your lived experience evolves as you age.

Theres nothing about what you’re describing and planning that seems wrong or impossible, and I dont think you should worry too much about justifying its worth. As I said earlier, the proof is in the pudding. I see that statement as equally encouraging and cautionary. Since you are clearly driven to do so, I say pursue it and let us know of your successes and failures along the way. The hurdles others have mentioned are real for sure (and your optimism may be clouding your estimation of them) , but they could be far worse. You could be trying to re-speciate extinct tortoises from limited hybrid genetics! Id wager the age to sexual maturity of a tortoise alone makes tree breeding look like child’s play.


Glad to hear it :slight_smile:

Ha ha ha :slight_smile: These days I often finish work around 11pm or later. But I figure it’s worth it. So far this year I made (well this is just for the seeds I have processed so far so the actual number is larger) 72 different crosses between domestic tomatoes (some of which are already domestic-wild hybrids) and 6 different wild species (104 in total if not only including the crosses with pure wild species), and will soon be harvesting the seeds from those crosses, some of which have been crossed again - plus I have more crosses to make before the year’s end - it should be 3 cycles in total this year, though more than that may be possible). Not to mention today having spent all day doing interspecial pepper crosses. So yes you’re right, this kind of work can take a lot of time, but that depends on how much one wants to do and how much one shares the work out amongst a community, which can be a great way. I just decided that I wanted to do what would usually take several years, in one, and figured having an intense year would be worth it. Well, it might be an intense couple of years. But the way I see it, if you start strong, especially if making a hybrid swarm, the whole project has much better chances. So I don’t expect it to be like this once I switch from speed breeding, to environmental selection. I can let nature do most of the work then, like I have done with some populations this year also. Much more relaxing at that stage, mainly just about preparing the ground, and processing the seeds at the end of the season. I imagine with the fruit tree idea also the main work would be seasonal, like the grafting stage, and the time planting and tending to the seeds. Also not forgetting that the speedy method I proposed above for fruit trees requires a lot more work than slower methods - I was deliberately giving a speedy method to address that concern. But sure, what I’m talking about does require work!

Though it’s all scalable also. I could have done a lot less work with tomatoes had I chosen lower diversity, for example. And continuing, I can chose to work with as much or as little as I like, with the seeds I’ve created up to now at my disposal for whenever I want to germinate them. I’ve already filed some away and am focusing right now on a subset of them.

But yeah I guess it takes an unusual kind of person to consider the kind of thing I’m suggesting.

Anyway thanks for the encouragement. I started this discussion really just out of curiosity and to learn more about the possibilities of fruit trees. I have no intention of making a fruit tree landrace right now. But for sure I keep an open mind about doing it in future. That’s dependent on a few external conditions. Or this discussion might even inspire some others to try!

Perhaps a good way of bringing this topic forward would be:
Which species could suit an interspecial fruit tree landrace project?

I’m thinking Prunus salicina could be a good candidate.
What other diploid species would be suitable to cross with it?
And what other interspecial combinations would you folk recommend?


Yeah I must admit I don’t get it? But hey it’s me so no worries. I just don’t see the point of it? All tomatoes grow here in the summer. Some better than others but most of the hybrids grow extremely well already. And the variety is amazing. For example I’m growing two hybrid and one heirloom cherry tomato. Each have produced around 300 fruits. The heirloom is about my 8th time I planted it. Using seed from the previous year. I decided to let it go as I prefer the hybrids although I do grow a few heirlooms I like of regular tomatoes. I like the black tomatoes and only grow them. I also grow fig and pomegranates here in Michigan but have to protect the plants. I get around 500 figs a year. Only one fig will actually grow in ground here and produce before winter. But it’s not very good. I only keep it around for ornamental reasons.
I plan to breed new pluots as the flavor range is amazing. One can get some wild crazy looking fruit too.
I also work with brambles and have five cultivars I developed so far. I met most of my goals so not sure what I will do next? Mother Nature helped me out and a volunteer purple raspberry came up in my yard. Which is a cross between reds and blacks. In this case it was a primocane fruiting black. So I have the first primocane fruiting purple raspberry. Discovered in 2022.
Unlike other purples this one has excellent flavor. Tastes a lot like a boysenberry, just outstanding!
I’m going to try and keep it going. I’m cloning two plants via tip rooting now to have a couple backups. I also developed a yellow that is very productive. Most are not. I’m trying to have various colors and I’m working on developing an orange colored Rubus idaeus. So far I have only developed a pink but I have faith! One was developed in Great Briton but not offered here else I would just buy one.
I mostly grow California developed pluots nectarines and peaches as any prunus species grows just fine here. I like what Zaiger has done so use his cultivars in my breeding. I do avoid those susceptible to bacterial spot as it’s not an issue in California so they never bred it out. Still only a few are so no big deal as we know which ones are susceptible. One could always spray if they really wanted to grow it.
Making a landrace sounds difficult. And I’m not sure when I would call it done?
With tomatoes between the amazing tasting heirlooms and the disease resistant hybrids I would not want to compete in that market. I was a member of tomatoville and although I didn’t participate, but enjoyed reading about the dwarf tomato project from the start to the finish. An amazing project that developed over 90 new stabilized varieties. Members grew out the seeds all over the world. They found it took about 8 generations to stabilize a variety. A few seed companies are now selling them.


The point with tomatoes for me is about making it easier in this environment, in which many people struggle with tomatoes outdoors. The main issue is late blight, and only some specialist hybrids are free from that problem though as late blight adapts, their resistance will likely be overcome. Those hybrids also keep costing money each year, you can’t use them in the traditional way of saving seeds, so that’s a big negative. Plus they don’t taste good. But the seed thing is twofold - the cost is real for many people here so that is important. Sustainability is important too, not to have to depend on seed companies, and we have already seen that situation’s weakness with a dramatic pause in the availability of seeds, and I expect that to happen more drastically in future. But above all, saving seeds because that’s the essential to give people the ability to adapt the populations to their land and growing habits.

Almost all of the interspecies tomatoes I grew this year tasted better than all of the fully domestic tomatoes I grew, which included some very delicious varieties including some heirlooms and some new crosses that I was using for their traits regarding climate adaptation, size, growth habit etc. And the very best tasting were all interspecies crosses.

So, this is about disease resistance (not just late blight); cold tolerance; flavour; ease of management (less de-suckering and less supporting); earliness of production in this specific climate; resistance to pests; ability to bear the new hot dry spells without being watered; and the ability to keep adapting to changing climate, pest, and disease pressures as time goes on. There are a lot of very valuable traits in wild tomato species. And a whole world of new flavours in their crosses.


Thanks for the follow up.

Yeah, planting out a bunch of lemon seeds and hoping for hardiness to miraculously appear, in this case at least, is the wrong approach. Lemons have basically no genetic potential for cold hardiness, no matter how your arrange those genes around, a few hours of more then a few degrees below zero is going to kill the tree. To say nothing of the fact that most lemon seeds will be clones of their mother plant.

There are some cold hardy “lemons” that aren’t true lemons, either rangpur (mid twenties I think), Meyer lemon, rough lemon (both low twenties), or ichang lemon (teens, though this one has no citron genetics so it really isn’t a lemon even in the loosest sense) and just enjoy that lemon. Planting out those seeds en mass still would be pretty pointless, since they’d mostly be clones, and citrus take several years to develope much cold hardiness.

If someone were really committed to breeding cold hardy lemons, and had a big greenhouse, they might could get some citrons and cross them with an appropriate cold hardy citrus. You’d need something that gave mostly zygotic seed, was quite juicy, and sour enough that the progeny would be sour enough to be good lemons. Smooth Flat Seville is hardy to the upper part of the upper teens and zygotic. But that’s not likely to get you much more hardiness than a rough lemon, even on the F2 generation. Might could try crossing with a poncirus hybrid, preferably one of the zygotic ones like US-1279, SuperSour 1 and 3, Bishop citanderin, or one of the Conestogas if any of them are zygotic. But going that route, while you’d have cold hardiness and zygotic seed, the juice content would probably be mediocre, and the poncirus yuck might come through. So maybe a second round of crosses, with the best of citron x Smooth Flat Seville and the best of citron x poncirus hybrid, at which point you’d have something ½ citron, about ¼-⅛ mandarin, about ⅛ pomelo, and about ⅛ poncirus (and a gigantic greenhouse). Given enough money, time, and luck, a true or nearly true lemon hardy to the low twenties or maybe even into the teens sounds possible. My gut feeling is it’d take about three decades, though ideally you’d tack on another five to ten years to properly trial the final generation.

I really like this.

Making really wide crosses like this, or like in my citrus example, is what gets me excited. While more challenging and failure prone, the potential reward seems higher as a general rule. And tomatoes, with the huge variety of wild relatives, fast generational turnover, and ease of working with, together with the fact that so many people grow them and that there are a lot of disease and other problems that need overcoming, are really a good candidate for this kind of breeding work. Heck, even the landrace idea makes sense here, since tomatoes have to be reseeding every year.


Sage hobilus

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For many species of fruit trees, that trick does nothing to speed things along. And even when it does help, it doesn’t do so evenly. You’d likely be selecting for what you might call “seedling-grafting precocity” (I have no idea if there’s a term for that?), which may eliminate many other linked traits you’ll want to keep in the population.

For avocados, maturity usually takes at least 4 years from seed, and occasionally 10+ years, and you can’t really judge the fruit for a few years after it starts bearing. I’d say 8 years per generation would be a safe estimate, though you could push it a little lower if one of the traits you’re selecting for is just normal seedling precocity.

Even for other types of fruit trees that bear sooner, it seems very, very ambitious to hope to get to any level of trait stabilization within a lifetime, assuming you start with a diverse population.

What other traits besides precocity would you be attempting to stabilize? Fruit size, color, acidity, flavor, flowering time, brix, cold tolerance, heat tolerance, drought tolerance, disease tolerance, unique soil parameters, resistance to pest pressure, high (or low) vigor, self-pollination, growth habit, etc.?

In a true landrace, those things all vary a bit, but have usually been narrowed over time by local climate patterns, community expectations, or farming practices. If you’re trying to reach even a much lesser level of stabilization with most of those at an accelerated pace, the logistical challenge would be daunting when it comes to tracking trees and their traits and deciding what to cull and what to favor.

I have a database of just a few hundred avocado trees grown over the last 3 years. I struggle to keep things updated often enough to be useful. And I’m currently selecting for only a single trait! Well, I guess there are many different traits that may impact being tolerant of local winters, but so far the only thing that seems to be a problem is long duration hard freeze tolerance for the above-ground parts of the tree.


Oh, damn, that really puts a spanner in the speedy plan, I didn’t realise the grafting only works speedily with grafts from adult plants! Do you know which Prunus species this would be speedy for and which it would not? And, in general for this principle, do you have direct experience with that or have heard reports from those who do? I assume so but asking just to be sure. Since I had heard that the flowering mechanisms are triggered from the… sorry I don’t know the right term but I’ll say the ‘mother plant’. For example, so far as I understand, short day tomato species will flower under long day conditions when grafted onto neutral day plants. Not sure if that’s just for mentor grafts or if grafting an entire plant onto a root stock. But that also makes me wonder, perhaps with those species you are referring to, it might not work with a full graft but might with a mentor graft? Although, a mentor graft might have other implications, since mentor grafts can bring cytoplasmic elements into the graft, so that may reduce cytoplasmic elements’ diversity, though, that might not necessarily be an issue.

Or rather than a full mentor graft (in which basically keep only the end 2 or so leaves on the grafted branch, removing all the rest as time continues, to maximise the mother (‘mentor’) influence), I wonder flowering might be accelerated even if just grafting onto a branch of a well established tree. Similar principle but just less strict, not bothering to remove leaves. Which would be easier. If anyone has tried either variations I’d be interested to hear if the results were similarly speedy to grafting an adult branch.

If it were me, I would not bother trying to stabilise size, colour etc. nor even flavour, just eliminate ones that were not useful, not tasty enough. And eliminate those that were not healthy enough for whatever reason. And yeah I guess if some had really annoying growth habit, remove those too.

Yeah so trying to be as speedy as possible to deliciousness and survivability so that it’s a workable useful population, but as you say, over a greater length of time, perhaps intergenerationally, the traits could narrow further as you say, if so desired. And that’s the beauty, continued adaptation, and the possibility for continued selection for phenotypes if desired. That can be so nice. Like take most crops … let’s say annual crops. People might keep growing an heirloom for 60 years. By the end, they have basically the identical crop as they started with. They might even have inherited it from their grandma, and pass it down to their own grandkids. But with an adaptive, your crop will be way better suited in the end than it was in the beginning, and over those 5 generations, all that growing from those family members has produced something potentially quite different than what they started with. I really like that.

In terms of tracking, the easiest way would be to track nothing. Just cull all that are too unacceptable, let nature cross them (particularly easy if an SI population), and keep planting more. Either on ones own land if one has the space, or distributed in the local community, getting other people involved in the passion of the project. Also if my grafting idea would work (whether that be due to mentor grafts or if the species were suitable or whatever), that would speed things but yes, require note taking and hand pollination, or even done without hand pollination but just faster culling of the insufficiently tasting trees, but you wouldn’t have to keep track further than knowing which graft was taken from which tree you have growing in the ground.

Like right now I am keeping track of all the crosses I’m making, all seeds kept very carefully. But this is because I’m focused on speed and efficiency. But people like Joseph Lofthouse don’t do that, they just remove the plants they dislike, and the rest, process the seeds altogether in one big mix. And that does work fine. He has great results. And it’s way less work! I’m just using a tighter method for the initial period for greater efficiency at creating a maximised hybrid swarm rapidly, as well as speeding up the creation of an (or hopefully 2) SI populations. So, there are options there on where one wants to choose on the spectrum of note taking and making specific crosses or not, vs. how urgent the speed of things is. In my opinion, note taking and keeping track of everything would pay off the most just for the initial 2 rounds of crossing for making the initial diversity. And not even in terms of tracking traits etc., just in terms of making sure one crosses everything with everything else, so you make the most diversity you can from the seeds you plant, whereas if you just let nature do the crossing, you might be planting 10 seeds that are all the same cross, and leaving out many others entirely. I’d say that’s fine once the project has been going for a while, but it’s at that initial point that you, or should I say I, would want to give the best chance of the genetics of all the individuals I have decided to start with, getting into the mix. And 2 rounds of crossing would be like shuffling the deck of cards. Once shuffled, deal them out!

Yeah, in reality, what I describe above might also end up mostly just being selection for that one trait, ‘delicious enough’. For most of the time, if where one lives is easy enough for that species or interspecial mix. It might even be a few years until a certain disease sweeps through the area, and maybe at such a time, all the neighbours’ trees are badly effected, and only 1/3 or 2/3 of ones diverse population effected! So cull all of those, and there’s your disease selection! And you have a whole bunch of really diverse seeds from those survivors to plant to replace the ones you removed. Maybe even your neighbours might be interested to have some seeds too, after such an incident!

Imagine if that kind of thing happened once every 10 years or so, maybe often different diseases or pests or weather events. Your neighbourhood might end up with very resilient trees!


More info on interspecific hybrids in case i’s useful for anyone reading this post whether now or in future:

In the last years, the interest for obtaining complex genotypes has increased, and for this reason, the interspecific hybridizations have been used.

Initially, interspecific hybridization was used to improve plum rootstocks. Thus, the plum rootstock ‘Ishtara’ is a complex interspecific hybrid between P. domestica, P. cerasifera, and P. armeniaca [30]. ‘Jaspi’ plum rootstock was obtained from the crossing between P. salicina Methley and P. spinosa. ‘Marianna’ rootstock was obtained from the combination between P. cerasifera and P. munsoniana [3].

Within the European FP 7 project, a breeding program for the creation of rootstocks with resistance to plum pox virus was carried out. Thus, at the Technical University of Munich, the ‘Dospina 235’ (P. domestica × P. spinosa) and ‘Docera 6’ (P. domestica × P. cerasifera) rootstocks were obtained [31].

In Romania, there were crossed varieties belonging to the P. domestica and P. insititia species with the same number of chromosomes, and several cultivars were named: ‘Silvia,’ ‘Ialomita,’ ‘Diana’ (‘Renclod Althan’ × ‘Early Rivers’), ‘Renclod de Caransebes’ (‘Renclod Althan’ × ‘Wilhelmina Spath’), ‘Doina,’ ‘Zamfira’ (‘Anna Spath’ × ‘Renclod Althan’), ‘Romaner,’ and ‘Iulia’ (‘Tuleu gras’ × ‘Renclod Althan’) [2, 6].

Hybridization between diploid species (P. cerasifera, P. salicina, P. simonii, P. besseyi, P. americana, P. nigra, P. munsoniana, P. angustifolia, and P. hortulana) can be very easy. For example, ‘Santa Rosa’ variety with American origin is a mixture between P. salicina, P. simonii, and P. americana [32].

In recent years, fruits of plum hybrids obtained from interspecific crosses have appeared on the world market:

  • Interspecific hybrids between P. domestica and P. armeniaca called ‘Plumcot®’ (e.g., ‘Red Velvet,’ ‘Royal Velvet,’ ‘Flavor Supreme,’ ‘Flavor Queen,’ ‘Rutland,’ ‘Plum Parfait,’ ‘Spring Satin,’ and ‘Yiksa’). In Bulgaria, Argir Zhivondov made crosses between P. domestica (‘Stanley’ cv). and P. armeniaca (‘Modesto’ cv.) and obtained the cultivar named ‘Standesto’ [21].
  • Interspecific hybrids between (P. domestica × P. armeniaca) × P. domestica and (P. salicina × P. armeniaca) × P. salicina. The name of these hybrids is ‘Pluot®’.
  • Interspecific hybrids between (P. domestica × P. armeniaca) and P. armeniaca called ‘Aprium®’ (e.g., ‘Flavor Delight,’ ‘Flavor Candy,’ and ‘Honey Rich Aprium’).

Source: Plum Breeding | IntechOpen

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