Inosculation aka fusion

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We are all familiar with trees being grafted. All those fancy japanese maples were grafted onto a basic green maple root stock. For a long time people believed that the genetics of the 2 species were separated at the graft point. Come to find out that is completely wrong, they swap genes to a point.

I'm wondering, could this be useful in creating a new variety? Or is the genetic swapping so minimal that it wouldn't effect the physical appearance to the in trained eye. If the swapping if genetic information was substantial enough, you could Graft on multiple cultivars to hone in on a trees characteristics. In theory it sounds like somebody could graft a branch then remove it once the deed was done.

Casey.
 

Silentrunning

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Casey, could you reference where you got this new information from? I would really like to dig into it further. Thanks.
 

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Hybridizing accomplishes that mixing of genes much more efficiently. Isolating a particular characteristic can sometimes be done by back-crossing F2's, but almost always results in sterile offspring. They can be propagated by cuttings, tissue culture, etc., but are also usually less vigorous than non-sterile plants. But not always. Of course Acer p. takes ~15 to 20 years to flower...
 

Wires_Guy_wires

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Hybridizing accomplishes that mixing of genes much more efficiently. Isolating a particular characteristic can sometimes be done by back-crossing F2's, but almost always results in sterile offspring. They can be propagated by cuttings, tissue culture, etc., but are also usually less vigorous than non-sterile plants. But not always. Of course Acer p. takes ~15 to 20 years to flower...
I'm hoping that you're talking about maples only, because sterile F2's are pretty uncommon in the plant world.

As for grafting, the 'mixed' genes usually aren't mixed genes, but they are mixed cell cultures: individual cells from both plants, mixed in a single physical structure. Meaning that pluripotent cells (like stem cells, and plants have a lot of those and move them around a lot) are moved between the two varieties. When testing a sample of cells, it's pretty hard to isolate a single one. More often, it's clumps or clusters of cells that are used. Those can show up in genetic analysis as 'originating from both plants' because by default, that's how genetic testing works: we use a known sequence that differs between the type 1 and type 2.
Let's do a small exercise, but in language instead of genetic code.

We need a start codon, we type this out as START
We need a genetic code that varies between the two, let's say GENCODE1 and GENCODE10001.
We need a terminate or stop sequence, let's say STOP
We need a mix to polymerise (synthetise) the sequences. So we can check them on elektrophoresis gels or sequences.
What do we want to know?
1. We want to know if every single type is present.
2. We want to know if both types are present.
3. We want to check if our mix works, so we use a piece with random code as a control.

Mix 1: Polymerizes type 1 only.
Mix 2: Polymerizes type 2 only.
Mix 3: Polymerizes type 1 and 2.
Mix 4: Contains our control sample for mix 1
Mix 5: Contains our control sample for mix 2.
Mix 6: Contains our control sample for mix 3.
Mix 7: Contains no DNA but all the other components to check for contaminations/flaws.

Results:
Mix 1: Positive. The code we sequenced is START-GENCODE1-STOP
Mix 2: Positive. The code we sequenced is START-GENCODE10001-STOP
Mix 3: Positive. The code we sequenced is START-GENCODE1-STOP and START-GENCODE10001-STOP
Mix 4: Positive, our mix works. The code we sequence is START-RANDOMCODE-STOP
Mix 5: Same as 4. The code we sequence is START-RANDOMCODE-STOP
Mix 6: Same as 3. The code we sequenced is START-GENCODE1-STOP and START-GENCODE10001-STOP
Mix 7: Negative, no DNA has been polymerized.

Now due to limitations in sequencing techniques, Mix 3 will most likely be processed as something like START-GENCODE100-STOP. Background of sequencing: some types of sequencing make use of the DNA being polar. In a way, DNA is dragged across a laser beam, letter by letter, to generate a sequence of the code. Like some old telegraphs work actually. Sequencing sometimes works by calculating the average of all parts that have crossed that molecular-sized laser beam. If it reads different letters on the same location at the same time, it will put out a weird, non-DNA letter like S or R. A technician later has to decide, based on how the signal 'looks' on what letter was actually read. I have done this for hours, weeks on end. And it's hard to see. But if there's a "00" added to a code, nothing screws over that signal. It will read out as a hybrid, but it's actually just a sample containing DNA from mixed sources. I too have had that happen.
A practical way to solve this, would be to isolate single cells, let those grow until you have enough DNA to harvest and to actually get a solid output, and then sequence them. This takes 6 weeks at least, and will cost a couple of thousand dollars more.
This is when only sequencing is used. When using electrophoresis gels, we can distinguish lengths between DNA strands. This has an accuracy of around 10 basepairs - It's been a long time, it might be more accurate nowadays. Meaning that if one code is 10 letters longer than the other, it will show. But if it's less than a 10 letter difference, we just end up in the same blob.

Our example codes differ just by 4 letters, meaning that if we use the polarity to electrically drag it through a gel (like sifting gold particles; same sized particles end up on the same places in the seive), they basically have the same 'weight' and drag, so they'll end up in the same location in the end.

Then there's RNA, the actual message originating from DNA that gets sent around to do stuff. Like, the DNA is the main chief and the RNA is the guy on the shop floor doing all the work instructed by the chief. Well, as you might know, the people on the shop floor move around a lot, from department to department and back. The same happens with RNA in plants, and even humans - loads of RNA in our body isn't from human origin. This means that when testing for RNA, you might even find a bacteria code in a plant. Does that mean the two have hybridized? I believe not.

But, the fun thing is protoplast fusion. This is actually melting two pollen together. And it's friggin awesome. Companies are using this to incorporate sterility into their seed stock, so that no farmer in the world can copy their genetics.

I hope this makes any sense, further reading can be done by googling:
- Genetics
- Sequencing
- PCR
- Elektrophoresis
- Biochemistry
- Or any of the terms used.
 

Leo in N E Illinois

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We are all familiar with trees being grafted. All those fancy japanese maples were grafted onto a basic green maple root stock. For a long time people believed that the genetics of the 2 species were separated at the graft point. Come to find out that is completely wrong, they swap genes to a point.

I'm wondering, could this be useful in creating a new variety? Or is the genetic swapping so minimal that it wouldn't effect the physical appearance to the in trained eye. If the swapping if genetic information was substantial enough, you could Graft on multiple cultivars to hone in on a trees characteristics. In theory it sounds like somebody could graft a branch then remove it once the deed was done.

Casey.


I think the zone near the graft union is where the mixing occurs. It is usually just cells from the understock mixing with the cells from the scion in the tissue structures. So if you look at the tissue, the individual cells are not all the same, some are from understock, some are from the scion. This does happen and is noticeable in grafted cork bark Japanese Black pines. For some examples, the corky bark will begin to creep down below the point at which the tree was grafted. It won't be as well developed, because not all the bark cells are the ''cork variety''. This is not genetic remixing. This is a Chimera.

Something like a chimera is what is happening in the mixed color patterns of a Satsuki azalea flower, the random sectors of a solid color, the odd stripe or fleck of color are from cells expressing color or not, and all the cells descended from that one cell. I think it is a tiger, or maybe a zebra that the chimera of skin tissue is the cause of the pattern. The tortoiseshell pattern in cats is a chimera origin.

basically, I don't see how it can be useful for bonsai, the Chimera of ancient Greek folklore was a hideous monster, made with parts of many animals.
 

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@Wires_Guy_wires I don't understand any of that. None at all. I'm speaking of using the pollen of either parents, pod parent of one variety or pollen parent from another variety, on the offspring (a back-cross), or pollen from one seedling of the above cross on another seedling of the same cross F1 x F1 = F2). This is usually an attempt to obtain an increase in some characteristic that is exhibited, but usually at the expense of losing some other characteristic separate from losing fertility that is almost always lost by F3, but not always.
 

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@Wires_Guy_wires I don't understand any of that. None at all. I'm speaking of using the pollen of either parents, pod parent of one variety or pollen parent from another variety, on the offspring (a back-cross), or pollen from one seedling of the above cross on another seedling of the same cross F1 x F1 = F2). This is usually an attempt to obtain an increase in some characteristic that is exhibited, but usually at the expense of losing some other characteristic separate from losing fertility that is almost always lost by F3, but not always.

There can be a giant loss of vigor with F2's, called inbreeding depression. But fertility loss isn't something that regularly happens. I have some +/- 14 breeding projects going on since 2009, of 7 different plant families. Backcrossing has never caused sterility. 'Almost always' would mean that at least 1 project would have become sterile at the F2 phase. But some breeding lines have been backcrossed over 6 times by now. Some plants do express this, but only because they're self-incompatible (sterile in the sense that they don't do the sexy stuff with direct family). Introduce a new member and everything is just fine.
I'm wondering where you're getting this information, because my text books only mention it in the fine prints, all isolated cases like rice breeding or in ornamental flowers, never as a general rule.. If there's a page that says it occurs more often than not, I'd like to read it.
 

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There can be a giant loss of vigor with F2's, called inbreeding depression. But fertility loss isn't something that regularly happens. I have some +/- 14 breeding projects going on since 2009, of 7 different plant families. Back-crossing has never caused sterility. 'Almost always' would mean that at least 1 project would have become sterile at the F2 phase. But some breeding lines have been back-crossed over 6 times by now. Some plants do express this, but only because they're self-incompatible (sterile in the sense that they don't do the sexy stuff with direct family). Introduce a new member and everything is just fine.
I'm wondering where you're getting this information, because my text books only mention it in the fine prints, all isolated cases like rice breeding or in ornamental flowers, never as a general rule.. If there's a page that says it occurs more often than not, I'd like to read it.
I'm a member of Ed Elslager Hosta Hybridizing Group. I'm more like a groupie, but I do a few crosses. Mostly, I use streaked x streaked and do some selfing, and I discover the occasional neat sport. Hosta is a tiny part of the plant kingdom, but lots of new varieties are the product of the hobbyists in clubs like ours, -and the Dutch. Here's a nice batch of streaked seedlings:20190323_143618.jpg20190324_101348.jpg Here also is a pdf of our meeting schedule this year. Anyone interested is invited to join us!
 

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Forsoothe!

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There can be a giant loss of vigor with F2's, called inbreeding depression. But fertility loss isn't something that regularly happens. I have some +/- 14 breeding projects going on since 2009, of 7 different plant families. Backcrossing has never caused sterility. 'Almost always' would mean that at least 1 project would have become sterile at the F2 phase. But some breeding lines have been backcrossed over 6 times by now. Some plants do express this, but only because they're self-incompatible (sterile in the sense that they don't do the sexy stuff with direct family). Introduce a new member and everything is just fine.
I'm wondering where you're getting this information, because my text books only mention it in the fine prints, all isolated cases like rice breeding or in ornamental flowers, never as a general rule.. If there's a page that says it occurs more often than not, I'd like to read it.
Now that I think about it, there are 21 species of Hosta and most of the hybridizing has been done between varieties. Almost all of the varieties are OP of uncertain parentage, or sports, so when I say fertility problems by F3, it needs to be remembered that exactly what generation a given parent or seedling is, is uncertain. There are a lot of varieties that are very picky about pollen source or sterile. Unless someone is working with species x species which is rare, there can be any recombination in your imagination. So, we may both be right! There is now some of variety x species work, mostly newly discovered species from the Korean islands, but the new species are mostly small-ish and plain IMHO, but are contributing red color to leafs and purple flowers as two hot characteristics being pursued for the market, along with miniatures. The new genes are welcome, too. Tetraploidy is even hotter, and that is lot closer to your end of the business of creating new plants via chemical treatments than the old fashion mummy & daddy making babies pollinators'.
 
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