The entire foundation of this thread is about to be wiped out as a breeding concern. Why and how? With full genome mapping of virtually all plants on earth, we will be able to map out advantageous genome configurations. Breeders will generate a full map (using AI of course) of a desirable plant and then build it from scratch using a full genome assembler. No matter what you think about genetic diversity or grexes or landraces or other composites of a genome, it will be so far in the rear view mirror that nobody will even consider it any more. Every gene and gene configuration imaginable will be available at the touch of a few buttons.
Personally I think biotech is inevitable and would applaud some clever use of it toward actual crop improvement or especially toward creation of whole new types of crops. Im not sure thats likely though. The profit motive and even more simply the need to have such efforts pay for themselves will continue to favor “improvements” that are objectively maladaptive, like terminator gene or round-up ready. Itd be nice if someone with some actual imagination were able to get ahold of such a device though. Youd be a good candidate @Fusion_power. Id try my hand at it too, why not. Maybe someday it would be like owning a 3-D printer. Seems technotopian and unlikely, but the rate of change has yet to slow down to date.
What of the many (most? traits for which there isnt a 1:1 or even 2 or 3:1 relationship between genes and their expression? Carol Deppe, in her book “Breed Your Own Vegetable Varieties” gives the example of the first genetically engineered tomato (‘flavr savr’ ) which (ironically?) was awful even by grocery store standards. Theyd tweaked one or maybe two loci thinking theyd only be affecting those traits that were “controlled” by those chromosomes, yet to hear her tell it, the impact on nearly every meaningful trait was palpable. I think its more realistic (and smarter) to use biotech (an AI for that matter) as a shortcut to overcome some hurdle, not unlike the way an engineer might use a calculator. It doesn’t eliminate the work, but makes it easier.
It’s not. But I have yellow caps and the color is recessive. To make primocane fruiting yellows I would have to back cross. I used the yellow not for flavor but because it seems to be resistant and/or asymptomatic to virus infection. Black raspberries are notorious for becoming infected. Cultivars kept dying out on me. So far the new hybrids seem to be healthy. It’s been about four years now. I really got lucky. I also developed two cultivars of red raspberry. Well neither is red. One is yellow and the other is pink. I also work with crossing pluots, nectarines, and peaches but that has proved to be harder. I lost some good crosses to unexpected freezes. They were young. So my efforts so far have not been productive. I got discouraged and gave up for awhile. I lost breeding stock too. I now have it back and will try again next year. I’m not that anxious to do it as it takes so long with trees. Plus all three are not easy to grow here. I feel I’ll make little progress.
Flavr-Savr tomato was from kludging a chunk of reverse sense DNA onto a gene in the ethylene biopath which controls fruit ripening. Fruit would stay red ripe for months without breaking down. In effect, ethylene response was blocked by the DNA patch. Breeders do the same thing today using a few naturally occurring genes such as rin (ripening inhibitor), nor (non-ripening), and alc (delayed ripening).
As someone mentioned above, you can’t breed what is not there. Cold tolerance tends to take hundreds of years to breed into a species from the tropics. Maize is a good example taking about 2000 years to move from Mexico into the U.S. and parts of Canada.
it may have seemed the height of sense at the time. Maybe the rest of the genetics just sucked? Thats about par for the course anyway. To the extent that people even eat fruits and vegetables, their sense of the potential of flavor, texture, aroma, is based entirely on the pallid offerings at the grocery store. Since we’re extrapolating from the present, what are the chances that all the biotech goo gahs in the world will be squandered making of all things more shitty produce?
A prime flaw in a lot of those types of trials in my observation is conflating mortality of small tender trees with lack of hardiness. Obviously there are reasonable limits to hardiness, but as you push against that boundary, youre apt to find individuals that can survive after establishment but that are still too tender when young. Nursery environments are tough to begin with too, while those type of selection efforts tend by their nature to be pretty brutal. Field growing is even harsher until the tree hits maturity and can hold its own.
That’s my plan with the decentralized avocado breeding effort I’m organizing here in the PNW. I’ve got a few dozen allegedly hardy cultivars on a handful of greenhouse multi-graft trees, hoping for magical recombinations of different traits that impart cold hardiness.
So far I’ve started a few hundred seedlings from seeds I’ve sourced from other growers in cold areas (mostly northern CA and northern FL). I’ve distributed about 30 of those this spring to members, planted about a hundred (many dead now), and have another 60 or so to distribute next spring.
My greenhouse trees are large enough now in year 3 that I hope to actually have fruit next year, barring any greenhouse catastrophes.
I’m hoping I’ll be able to continue germinating and giving away seedlings from these trees for the rest of my life, and maybe by the end of that there will be a small population of Cascadian-adapted avocados that future breeders can use to select for quality.
It’s definitely a genetic bottleneck, but that is not necessarily a bad thing, especially if some of these hardy cultivars from different regions have never been crossed before. I wish I could look for isolated specimens in the colder parts of the Mexican highlands, for example, to add even more genetic diversity, but unfortunately it’s basically impossible to legally import avocado seeds or budwood from Mexico.
But in the end, I’m not thinking I’ll create a landrace, that seems like something that would be many lifetimes away for long-maturation plants like avocado trees. I guess a decentralized bioregional breeding project is basically step one towards a landrace, though.
I’m going to make a guess that such an effort will only result in a very slight understanding. I am under the impression that while we do have some understanding of the role of some genes, it might be somewhat comparable to our understanding of whale language. We know what some sounds mean, and we have catalogues countless sounds, but we have by no means cracked the language.
I would bet… well all of my money really, on that never being true in my lifetime.
And that’s not to say direct gene manipulation doesn’t have value.
Yeah, there is some really deep immorality in a lot of commercial breeding for sure! Terminator genes and male sterility being among them, and yes for sure the use of toxic chemicals. I am so much more appreciative of efforts like making perennial rice and that kind of thing, that can be geared towards enabling soil building rather than the intense efforts leading to radical soil erosion, the death of river systems, and all that devilish nonsense.
I’ve heard great things about that book! Also for an insight into why commercial tomatoes are generally so terrible (and for sure customers actually don’t want them, blaming customers is really stupid! To believe capitalism is driven merely by the demand of consumers is intensely naïve, and in particular overlooks the generally psychopathic nature of corporations), this video gives a lot of insight, and goes into breeding programs also:
And I totally agree with you about the unpredictable nature of genetics. It’s a complex system, completely different from some kind of linear mechanistic system.
Looks like a cool project but very long thread, would you be willing to give a brief summary of how the project went? I see it seems to have been started in 2019, curious of the progress. Oh wait… I meant the citrus project i the link within the quote. Funnily enough I am growing astringent persimmon though. From seed But only 2 or 3. I’d love to grow more but had limited seeds, and they’re very far in the back seat due to all my other work. But I hope they survive. I chose the older astringent type because the fruit is still delicious (when old enough) but you can also use the younger fruit to make kakishibu, which is excellent for colouring cloth, and for applying to wood to protect it. Wonderful substance.
Fantastic!
Have you just been planting the seeds you collected? Would you consider the idea I proposed, of growing the seedlings (maybe even in a greenhouse for speed and protection) then making grafts from them to an older tree so that you can speed up the time to first flowering, then cross them all, then use those seeds to plant out? I’m figuring that would be the fastest way of getting those magical recombinations.
Or if that wouldn’t be possible due to your climate, maybe grafting them to a friend’s tree in a warmer climate or well established greenhouse tree? Basically a shortcut to making that hybrid swarm. Though if not I of course wish your project the best of luck anyway!
Yeah there could be ways of working on a distributed landrace project if pollen were exchanged. Might be hard in the post depending on how long that species’ pollen lasts but I did have that thought about bananas, like sending and receiving refrigerated pollen. Just as an example, I have a tomato pollen library in my refrigerator Just from my own plants but it means they don’t have to be flowering all at once for me to still be able to make crosses.
According to the literature, that doesn’t work for avocados the way it works for some species, such as apples. I have tried a couple seedling grafts onto mature greenhouse trees, and those grafts still haven’t flowered in 2 years, despite the rest of the (mature) grafts on those same multi-graft trees flowering.
However, the largest seedling in the project is ~8 ft tall, and if this winter is mild (as El Niño usually means for the PNW), then that tree might reach flowering size by the end of next season. There’s not a whole lot of clarity about what triggers maturity in avocados, but total leaf nodes seems to be part of it. In any case, it usually occurs between 8’ and 15’ height, which typically happens in 3 to 8 years, but occasionally it takes many years beyond reaching that size.
I have already collected a wide range of Mexican-race avocado cultivars that are grafted together in one greenhouse, so at least initially I think it will produce the widest range of traits to hand pollinate these cultivars in as many combinations as I can.
Because this is just locally “distributed,” all within a relatively short drive, the plan is to exchange scions among members if we find any promising seedlings, especially any that make it to maturation outdoors here. While pollen could also be swapped, it makes the most sense to centralize the seed production at least initially, and decentralize the hardiness testing. And I’ll be continuously adding and removing grafts from the “mother trees” in my greenhouse based on the survival rates of each cultivar’s seedlings, as well as the apparent hardiness of any grafts tested outdoors.
After reading partially through this thread I came to the realization that there doesn’t seem to be a full understanding of what a landrace is among some participants.
A landrace is:
*A genetically and morphologically variable population that has some common traits which make the members recognizable despite the variation.
*Originated and maintained via some form of isolation from other types of the species.
*Generally not recognized as a landrace unless it has some history behind it, but even without the history could probably be defined as a “grex” (if it’s of hybrid origin).
*Can be considered well adapted to its native region in that it has been through enough generations of natural selective pressure to weed out some traits which may be found within the species at large, but which would be disadvantageous in that region.
A land race is not:
*A uniform population.
*Heavily culled for a narrow range of traits.
If anything, a landrace could be considered more similar to a subspecies (though artificially derived) than to a cultivar.
Good definition/summary @JohannsGarden! I hadn’t ever really thought about the Venn diagram of “population” vs “landrace” vs “grex” vs subspecies. I would have mostly thought about these kind of qualifiers:
It was with these kind of thoughts (articulated less clearly in my own head) that I said this about my own avocado efforts:
If we look at existing landraces they are attributed to regions, not individuals. I greatly respect the breeding work done by some to develop landrace plants, but realistically any breeding work is just the foundation. It’s not truly a land race until it’s moved beyond the breeder and through the rigors of time and culture.
I wonder if we shouldn’t have translated the term when we picked it up from the continent. Something like “folk breed” might have got more of the meaning across.
Yeah I’d say that all fits with the way I was using the term, except maybe for:
History is a subjective thing of course. But if a person or group of people spend time adapting a population over multiple crop generations to their land, then it has a history. Most landraces have a longer history. But everything starts somewhere. Like, most countries have a very long history, whereas some countries are very new. But they all have some kind of history, just some have a longer one than others.
As for grex, I think of a grex as a population all deriving from the same two original parents, like being siblings, where as a landrace can have potentially many more. Also my impression is that a grex might not have any specific adaptation to a particular land. So, very different from a landrace. And I would think that a grex might be a good population from which to start a landrace project, though I would rather start with something much more diverse, which I would tend to call a ‘hybrid swarm’. I’m not even sure of the strict definition of ‘hybrid swarm’, but I personally use the term to refer to a situation where one has made many F1s from many different parents, and then if possible crossed all those F1s (or maybe F2s or whatever if one wants to select a bit first) with each other, to make a richly diverse population. Welcome to correct me if I am wrong with the way I am using that term.
The kind of landrace I have been discussing is one where we’re trying not to homogenise too many phenotypes. But, my impression is that there can be quite a spectrum of this. Such that some traditional populations labelled by botanists as landraces, might still have some phenotypic variation, but way less than the approach I am advocating for, which some people might consider to be a ‘narrow range of traits’, though ‘narrow’ is of course a very subjective term. That’s my impression anyway but feel free to correct me if I am mistaken.
Actually, on that topic, in the video of Dr. Debal Deb, whose work is absolutely admirable, I did as it happens find myself wondering, when he was talking about the traditional method of maintaining rice landraces in India in the video I shared above. He was talking about a very strict method of maintaining them by selecting for… it sounded like pretty much all their phenotype traits! I couldn’t help wondering, is that really how they were maintained in pre-colonial India? Or has he perhaps been influenced by the more modern Western ‘heirloom’ trend which I have the impression is more fanatical about selecting against ‘off-types’. Like, it could perhaps be that the native Indian landrace culture really was that strict, and their landraces really were that homogenous. But at least that is not the level of strictness I get the impression some landraces were maintained with in other cultures where it seems to me they were more diverse, and more in line with what you just said about that. That part of his lecture did conflict with my own understanding of landraces in general.
By the way what is your source(/es) for your criteria?
I would qualify that by saying that it could do just that on the breeder’s land! Or on their and their neighbours land! That’s after all how so many of the ‘old’ landraces also came into being!
Of course this also brings into question, what about if I buy seeds from that breeder’s relatively new landrace, or for that matter, from a 1,000 year old landrace from some ‘exotic’ area straight from the indigenous people of that area - is it still a landrace now, in my fields? This could perhaps be merely a linguistic issue. But from one perspective, we might have to wait until it adapts to our land (if it does), to call it a ‘landrace’ again, at which point it might be then a new and different landrace! So perhaps we would have to say it’s ‘from’ a landrace until then.
But yeah, my focus is on making new landraces. The only crops I’ve grown ‘from’ old landraces are one tomato landrace from Colombia, and some rice landraces. Both for the purpose of breeding. I do hope to make a nice new rice landrace!
Another thing that comes into this is for example Joseph Lofthouse’s ‘landraces’. When they are community projects bred in various lands which are quite different from each other, I find myself not thinking of them as landraces at all, but rather, more as hybrid swarms. But the ones which are very much focused on his land, but with phenotypic variability considerably more than traditional landraces, I find myself unsure of what term to describe them by. But some of them I really can think of as landraces, really suited to his land and very successful there, often way more than any other variety there is, from the work he has done. But I see it as his kindness to deliberately keep the diversity considerably high specifically to enable the sharing of them over a wide spectrum of lands. So the aim overlaps with the traditional aim of landraces, but has that added factor of consciously wanting to share them over a wide area. in one way almost ‘proto-landraces’, or perhaps the ones bred communally in quite different places as ‘proto-landraces’ which do have some specific adaptation but are basically very highly suited to sharing for other people to use in starting their own landrace projects. But the ones more specifically adapted to his place but with a consciously shareable level of diversity, perhaps simultaneously ‘landraces’ and ‘proto-landraces’. Well anyway, all these labels are us humans just imagining conceptual boundaries in a boundless world. But anyway, there are some of my thoughts on it. It’s a rather uncommon thing to be deliberately making diverse populations to share with people, so no wonder the language isn’t quite settled!
I think you’re conflating the idea of a stabilized “heirloom” cultivar that is generally true to seed with a “landrace” (geographically isolated population sharing certain traits).
Landrace has built into it the idea that it’s been basically the only “type” within a bioregion for long enough that all the various traits within the population have relatively stabilized due to a long period of geographic isolation from other regions where the species grows.
Using the same term for a population that has been bred in a single person’s control on a single parcel of land seems like a misuse of the term. That’s just a new cultivar or breeding pool that was selected using a method of breeding that is attempting to borrow from the process by which landraces form. It is not a landrace itself.
Just from my own plants but it means they don’t have to be flowering all at once for me to still be able to make crosses.