Seeds from grafted trees carrying improved genes, or not?

Yes, plastids. Thanks for the Science link - it’s a high quality article. From other sources I’m aware that some combinations of fruit/nut rootstock and scions have no improvements while others have resulted in better disease resistance, or fruit production, or even fruit coloration (in one Citrus I’m aware of).

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This https://outline.com/ allows you to grab the web address of any article and view it.

Never in a million years did I see this topic going in this direction. I have a lot to learn. Richard I appreciate your links to Phys.org. I’ve got it on the top-line of my browser. I like it.

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I have no knowledge of what is referred to in the above articles. So I am ignorant of this.
However , the commonly accepted belief in horticulture being. There is no gene transfer from rootstock to scion .
There can be spontaneous bud mutations, resulting in " bud sports ",that can differ genetically from the original scion variety. This is not thought to come from the rootstock, but just random mutation.
But they did not teach me about horizontal gene transfer in bacteria when I was in school, as it was not generally accepted at the time, …now it is !
So who knows ?
We have a lot to learn yet !

A exception to this may be viruses being transferred from rootstock to scions .

Yes but I would attribute all of that to improved nutrition via a superior root system. Not to any genetic transfer. Why we graft at times, just like the fig varieties that develop poor roots. Grafting can help a lot. As some one who has actually worked with cells. One study means nothing, can the results be duplicated? It is so easy to mix cell contents, I still am suspect of actual DNA exchange. Have they ruled out contamination? I assume they are doing it right. All the same I would not be surprised if they are mistaken. What mechanism did the transfer? What rejection issues are in play? I could not read either link so as to what they found and how they found it I’m clueless? Doesn’t matter I don’t know enough about it to contribute anyway… I can say 99.9% of grafts are unremarkable. I would expect genetic material from both to mix extracellular, as they have a circulatory system. Yet to combine intracellular material? By what mechanism? How did they determine the transfer and the transfer molecules in play?

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@Drew51
I agree that the study does not show any RNA or RRNA transfer occuring – nor do I believe there would be. The paper is from 2009. Perhaps those or some other authors have since fingerprinted offspring of rootstock+scionwood combinations.

There was a related thread on this subject here a few years ago. Create new species of plants by grafting!

Maybe I’m missing something, but after reading the article, it doesn’t sound like that big of a deal to me.


The DNA transfer was limited to the graft union only. The Scion and rootstock both showed no sign of DNA transfer in the testing, and the disease resistance was not passed past the graft point. It sounds like a graft chimera to me: Behold the Graft-Chimera! | unconventional stories from an apple farmer
While graft chimeras are cool, they’re not easily created (although easily propagated once created). So while it’s cool, it’s not like there’s evidence of fireblight resistance passing past the graft union from a rootstock to a scion.

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Well Dan, just the title alone is an oxymoron. Apparently someone is unclear about the definition of species.

There is a lot to learn here.

I won’t comment on the process of gene transfer (or lack thereof) but here’s my experience. In 2014, I grafted Methley Plum onto 3 different varieties of Chicksaw of Hybrid trees. In 2015 they all flowered , set fruit and ripened at the same time as the original mother tree. There was no noticeable difference in the size, texture, color and taste of the fruit from the mother tree to the grafted branches. In 2016 they all continued to flower and set fruit together. However, at harvest time the grafted branched ripened about 10 day later and the fruits were about 20-30% larger, but same taste and texture. Come 2017, all started the same. At harvest the grafted branches matured about a month later than the original mother tree. This year the fruit was about 50% larger and they took on a elongated (drupe) shape and the color became blushed red/green. The fruit also became really firm. 2018 – 2019 almost everything was the same as 2017, except now they mature at least 2 months later (they hang forever, so I remove them from critters) and they now taste similar to the AU producer plum.
All three (3) varieties has shown the same characteristics regarding Methley.
Strange as it may seem, that’s my experience with grafting change.

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Very good info, thanks. I agree. Cells wounded at the union could easily pick up intracellular material from other wounded cells. So explains the graft area. Interesting subject!

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Yeah, after I posted that I tried to find other supportive studies but had no luck. I believe its safe to say that genetic transfer could happen at the graft site and the grafting could result in physical changes to what is grafted (and the fruit), but gene transfer from rootstock to fruit appears to be unlikely.

Further reading the actual article:

[…] our finding that gene transfer is restricted to the contact zone between scion and stock indicates that the changes can become heritable only via lateral shoot formation from the graft site. However, there is some reported evidence for heritable alterations induced by grafting (7) and, in light of our findings, these cases certainly warrant detailed molecular investigation.

The paper it sites as (7) is 7. Y. Ohta, P. V. Chuong,Euphytica24, 355 (1975)

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There are peer reviewed articles indicating some chemicals can transpose across graft unions and directly affect DNA in the scion. One example easily found on the net is of grafting a white tomato variety onto a rootstock that has all the genes to produce red tomatoes. The white tomato scion will produce pink fruit. Not only that, seed saved from the white tomato scion will produce plants that make pink fruit. The evidence - and it is very solid - is that some DNA changes do occur in the scion caused by rootstock influence. For some relevant reading. Lamarckism - Wikipedia Epigenetics - Wikipedia Genomic imprinting - Wikipedia

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Lots of interesting ideas in this thread. I have always wondered how some of this worked in relationship with grafts and seeds of different fruit. Now you all have me thinking about planting apple seeds and seeing what I can come up with! :grinning:

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I think there is plenty still to chew on here. We have come quite far in the new field of Epigenetics with regards to humans, yet we have barely scratched the surface of the truth. With regards to epigenetics in plants, have we even thought about scratching the surface? I also think that what we currently call “random genetic mutations” might one day seem not so random after all.

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Actually to me it appears to be going more the other way. More genes are formed randomly than we thought. We discovered the purpose of junk DNA. It is a reserve gene pool. Mostly untested randomly formed DNA sequences. Sometimes a strange gene appears and we could never explain it’s origins. Now we know it was in the junk DNA. Why only occasionally a sequence or sequences are used from that portion the chromosome are not really understood yet.

What I was getting at is that I believe there is an element of intelligence involved. Of course we can’t prove it yet, but I don’t believe anything regarding creation is random. I think we’ll only discover that intelligence is involved increasingly more than we previously assumed.

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OK, I get it. I guess you should not rule out anything.

You know many trees will merge roots . The roots run into each then grow into each other. Sometimes this is accomplished by mycorrhizal fungi linking the trees of the same or similar species. I saw a study on peas or beans? Forget? Where they were linked by mycorrhizal fungi, and when the first plant got aphids, all three produced insect defense chemicals. as all plants in the network were alerted of the danger by the fungi connecting them. Unreal what we are finding out. A whole forest can be connected. Some mycorrhizal fungi are one organism 20 miles or more wide.One was found in my state Michigan. These large fungi produce mushrooms the size of the Stanley cup! Very rare to find. I have seen pictures of the mushrooms. They also produce a nectar that the bees drink in old growth forests.

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WHAAAT!? Bees drink mushroom nectar? New niche honey crop.

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Yes and bees who consume the nectar are resistant to colony collapse disorder. It is believed that the destruction of old growth forest and the decrease in these fungi have contributed to colony collapse disorder due to weakened immune systems. Currently studies are underway. the fungi is being propagated for use in the study.

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