Are you able to advise on how exactly we do the graft? I was just thinking of jamming the tomato seedling scion into a thin vertical slit of the goji scion.
This year I did plug grafting of seedlings and sealed them with glue. You can use a toothpick to make a hole in the rootstock, prune the roots off the tomato seedlings and just plug them in there, then put little super glue around the junction. If a toothpick isn’t the right diameter to match your small tomato scions, you can get a jewelry drill but set like something that goes from .5mm to 1.5mm to make the plugs. This works really well and allows you to work with a variety of different seedling diameters for different species.
Then you have to have them in low light and high humidity, where you gradually decrease the humidity over the span of a couple weeks.
Very useful, nothing beats practical experience. What do you use to control the humidity?
I used those mini greenhouse domes since you can gradually reduce the humidity easily.
Things I have occasionally observed in tomatoes:
1- Solanum peruvianum may re-sprout from the roots after a freeze.
2- Some plants in the lycopersicon/habrochaites/pennellii interspecies hybrid clade have rhizome looking roots.
I read that goji berry and tomato can cross. Goji survives zone 4/5 winters.
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Do you recall where you read that?
There’s a thread on the OSSI forum with a link to that paper. They used embryo rescue, and if I remember there was a good bit of sterility.
Ha! I read every thread on the Open Source Plant Breeding Forum.
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Thulahn,
Here are some of the patents for goji tomato graft hybrids. There are more of these, so for sure a lot of work has been done there.
EDIT: Never seen a graft hybrid method like this before, this is so cool ! They induced adventitious roots to form at the graft union which are “transformed.” These could potentially be cell fusion hybrids or chimeras, but in this case it seems like they are “transformed tomatoes.” Very cool!
Substitue “goji” for “medlar” below
“Therefore, on the basis of establishing a high-efficiency grafting system by reducing the lignin content of the medlar cells, a technical system of the level gene transfer between medlar and tomato cells is established, and the tomato transformed root obtained by researching the induction method of adventitious roots of tomato is an effective way for solving the current strong root biological breeding of tomatoes.”
This seem to indicate that they used this method developing tomato cultivars with more vigorous root systems.
Another related one regarding the vigorous “chimeric roots” !
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This is the first one I remember looking at, from 2010. “Medlar” is an incorrect translation for “goji”–that’s often what it gets auto translated as.
Another new one I haven’t looked at yet:
This one definitely has better photos than that old one. You can see this is not mentor grafting, as there is no Lycium leaves and lots of tomato leaves.
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@Ascentropic This is wild. I feel like I’ve arrived very late to the game! How would these patents even be enforced? How can you police someone’s actions to such an extent.
Most of the west is very late to the game on this. Chinese not only likely invented grafting but have several references in old texts to graft hybridization and distant grafts, so they don’t have the same mental blocks there. Many people still don’t believe its possible, even with all of this data. I’ve been posting on this subject trying to get amateur breeders interested since more than 10 years ago. Its starting to change a bit now I think with a continuing influx of studies, and well known biologists like Michael Levin discussing graft transformation and the power of plasticity more generally.
There are several reasons I wouldn’t worry about the patents. For one thing I think the mentor graft method will be more powerful than the above patents. One thing to understand is that these type of methods are trying to transform an already stabilized cultivar, and do it at scale.
Stick to the original mentor method, at first anyway. Breeders like us don’t mind starting with unstable wide hybrid seeds and doing mentor pruning on one or two plants, purely to generate the highest amount novel variation. The above research they are trying to get particular tomato cultivars to propagate vegetatively that are more vigorous and cold resistant. They aren’t trying to maximize transformation of the scion, or select from seedling variants. All of this has to be understood on a spectrum rather than on/off. Even in the above patents there are different degrees of selective force applied to the scions depending on the age of the Lycium rootstock, whether it’s allowed to have leaves or not, chimeric adventitious roots or not, or simply just being a wide graft like that last one I linked. Mentor grafting wide hybrid seeds is still going to be stronger transformation than those in principle.
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What are your thoughts on using wide mentor grafting versus wide hybrid crossing? I think there are pros and cons to each method. In mentor grafting, there is more control in some ways as we mechanically join one plant to another. Not all plants within a family are pollen compatible and mentor grafting gets round that. But wide crosses if successful will lead to a much larger mixture of genes in the offspring.
Its case dependent, but I agree generally if you can do the cross sexually you’ll go that route first because of the reasons you mentioned.
Some factors to consider: in wide crosses, sometimes you can do the cross but there are too many problems — fertility, linkage drag, bad combinability etc. Mentor grafting in one study was shown to de link traits that are otherwise only transmitted in tandem. Sometimes there isn’t an available relative to cross to, or there just isn’t what you’re looking for in the gene pool. Sometimes the biology of the plant makes it harder to do a mentor graft, such as with grasses. It’s easier to mentor graft two hardy woody plants, since you don’t have to collect seed and make the graft each year.
A productive angle is to consider how sexual and graft hybridization can mutually support each other. Firstly, for mentor grafting to work well, you want to use hybrid seed in the first place. If you didn’t or couldn’t use hybrid seed for mentor grafting, another route is to polyploidize your seedlings. Or if the graft is very wide, that will destabilize the little scions anyway. You can also use mentor grafting prior to crossing 2 species to break down hybridization barriers, this was shown in domestic tomatoes x peruvianum (it was regular grafting, mentor grafting will have a stronger effect).
In the case of tomatoes x goji, I think the embryo rescue plants had too much sterility, but I’ll have to go back and look at that paper to be sure.
I would approach this project by first acquiring domestic x wild tomato seeds, with wild genetics already giving some degree of the cold tolerance and perenniality you’re looking for. I think Joseph mentioned hybrids with arcanum, peruvianum, or other species can have some of these qualities. These seeds being wide hybrids will also be mentor able, they will have genomic plasticity (unless they’ve been stabilized for years). I would mentor some of these seedlings on goji plants, keeping this grafts in pots and overwintering protected for several years. That way you can transform the tomato scion at the same time as collecting transformed seed from them. Who knows, maybe doing this will even allow you to make a sexual cross without embryo rescue. Lycium species can hybridize easily, so you could do the reverse also.
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Right, I see. By allowing the mentor graft to proceed for multiple years we should see increasing amounts of genetic material migrate into the tomato scion, and therefore each year that we plant the seeds should yield tomatoes with increasingly goji like characteristics.
Could you talk a bit about why it’s important to have a hybrid tomato scion versus just a normal tomato scion? I get the sense that you’re after the genetic “instability” of a hybrid offspring.
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When you read Michurin, he is very emphatic on using hybrid seeds for mentor grafting. He noticed that using non hybrid seedlings produces hardly any transformation in the graft. He also noticed that mentor grafting older (already stabilized) hybrid scions didn’t work either. It was only the seedlings that were both young and hybrid that had the necessary plasticity. Likewise, the seedlings of the mentor grafted plant will have more variation than the graft itself (Michurin was mostly working with transforming the graft itself). You could add a polyploidy layer to this, to say a young allo-polyploid seedling would have still more plasticity compared to a diploid.
The spectrum of plasticity vs stability is related to stresses response. Basically Michurin was combining the stress of early developmental hybridity and (mentor) grafting. In his words plasticity is gained by “shaking loose” an organism from its (genomic and developmental) stability. You start to see the amount of plasticity as related to the total amount of stress. A distant graft is more of a stressor than a closely related graft and a mentor graft is more stressful than a normal graft.
We now know that transposons are a key part of the cellular mediation of plasticity, together with the epigenome. In my experience, reading about “genomic shock” and the “epi-transposon” system is very consistent with what Michurin is saying. In a wide hybrid, transposons from both patents are no longer silenced epigenetically, and they start to cut or copy and paste themselves around the genome like weeds. At this time, early on in a hybrid’s development, the genetic regulatory networks are not yet set up. We know that when transposons are mobilized, horizontal genetic transfer is also promoted. That genomic instability allows the young seedling to be more easily imprinted by the flood of foreign genetic material caused by the mentor graft. But it’s not necessary to get this granular to observe hybrid plasticity. For example, Reed talks about 2 different colored sweet potatoes coming from the same seedling shoot. I’ve noticed hybrids having changing leaf shapes, changing flower colors, and other traits that are plastic in a single plant.
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Correct, the seeds as well as the scions – its a twofer! I’ve never seen a study that did such a comparison, it should be interesting compare each year. You can get very creative and for example grow out the seedlings and cross transformed types back to the mentor grafted scion. You can add more species, cross different mentor grafted plants, use multiple different rootstocks, or a rootstock that has multiple species to mentor the scion with. You can really take it a lot of directions.
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I was reminded of this thread as this video came into my stream yesterday:
Grafting citrus
AI Summary:
In the YouTube video “WHAT HAPPENS When You Graft Orange to Lemon?”, the creator discusses his attempt to create a two-in-one citrus fruit by grafting an orange to his lemon tree. He explains that this process is possible due to the formation of a grapheme Chimera, but faces challenges due to the lemon tree’s survival and the potential compatibility issues with grapefruit. The creator also shares the difficulties of grafting citrus trees in California due to diseases and the importance of using disease-free budwood. He conducts an experiment comparing the effectiveness of aluminum foil and paper bags in protecting grafts and shares his experience with grafting Mandarin oranges onto a lemon tree, resulting in poor-quality fruit. Despite his efforts, the process of inducing a grapheme Chimera is difficult and ultimately unsuccessful. The creator invites viewers to share any easy methods for inducing this phenomenon.
It highlighted the mechanisms of gene transfer through grafting and the ultimate goal of inducing a chimera shoot that is a major conglomeration of mixed up genes.
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I’m trying to wrap my mind around this. When you eventually wanted to factor taste into the equation, would you then graft a tasty tomato variety on to the great (x whatever) grandchildren of repeated graftings?
I I imagine the first step is creating enough crosses to test cold tolerance. Once varieties are found to be cold tolerance selections can then be followed to select for fruit shape size color taste, but the biggest change is inducing cold hardiness first.
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