Sometimes I muse at how much import I place on my efforts vs how little they seem to matter. Its funny how we consider broad issues like hunger, the state of society, extinction, genetic diversity- our mental maps are veritable houses of cards. Realistically, in the end, we might hope to have only a very small impact. Probably no small measure of that impact will be nothing more than passing the torch and keeping the discussion alive so that progress (of one kind or
another) can continue to churn.
Weāre fortunate to be able to be here to have the conversation, knowing in the end itās probably relegated to the annals of obscurity. Lets not let our passions carry us away. I certainly never have
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 āimprovementsā 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 āBreed Your Own Vegetable Varietiesā gives the example of the first genetically engineered tomato (āflavr savrā ) 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 ācontrolledā 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 doesnāt eliminate the work, but makes it easier.
Itās 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. Itās 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. Iām not that anxious to do it as it takes so long with trees. Plus all three are not easy to grow here. I feel Iāll 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 canāt 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 weāre 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.
Thatās my plan with the decentralized avocado breeding effort Iām organizing here in the PNW. Iāve 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 Iāve started a few hundred seedlings from seeds Iāve sourced from other growers in cold areas (mostly northern CA and northern FL). Iāve 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.
Iām hoping Iāll 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.
Itās 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 itās basically impossible to legally import avocado seeds or budwood from Mexico.
But in the end, Iām not thinking Iāll 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.
Iām 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 betā¦ well all of my money really, on that never being true in my lifetime.
And thatās not to say direct gene manipulation doesnāt 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.
Iāve heard great things about that book! Also for an insight into why commercial tomatoes are generally so terrible (and for sure customers actually donāt want them, blaming customers is really stupid! To believe capitalism is driven merely by the demand of consumers is intensely naĆÆve, 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. Itās 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 waitā¦ 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. Iād love to grow more but had limited seeds, and theyāre 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? Iām figuring that would be the fastest way of getting those magical recombinations.
Or if that wouldnāt be possible due to your climate, maybe grafting them to a friendās 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 speciesā 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 donāt have to be flowering all at once for me to still be able to make crosses.
According to the literature, that doesnāt 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 havenāt 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 NiƱo usually means for the PNW), then that tree might reach flowering size by the end of next season. Thereās 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 8ā and 15ā 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 ādistributed,ā 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 Iāll be continuously adding and removing grafts from the āmother treesā in my greenhouse based on the survival rates of each cultivarās 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 doesnāt 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 āgrexā (if itās 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 hadnāt ever really thought about the Venn diagram of āpopulationā vs ālandraceā vs āgrexā 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. Itās not truly a land race until itās moved beyond the breeder and through the rigors of time and culture.
I wonder if we shouldnāt have translated the term when we picked it up from the continent. Something like āfolk breedā might have got more of the meaning across.
Just from my own plants but it means they donāt have to be flowering all at once for me to still be able to make crosses.