Grafted mulberries


#41

Then I did word it wrong. I was strictly referring to the aging process, excluding outside circumstances. In the mentioned discussion it seemed to be scientific conformity that no clonal propagation of plants can reset mutations.

I am only discussing your argumentation. As you said a theory must be falsifiable. To say something isn`t aging (to death) cause it has not been observed to do so, is a purely historic argument. It has to be acknowledged. But observation is not sufficient cause you could simply have to wait longer. So observation is not able to falsificate the claim something will not happen. The historic argument is supporting your point but that doesn’t mean other theories are bullshit. Thats not possible to say from a pure historic view.

The argument about mutations ultimately leading to death of a variety seems logical to me. But you are right I myself are a poor defender of this argument. I simply lack scientific knowledge. And I will not call out for help by other. But did you follow the linked discussion?


#42

My observation is that there exists zero empirical evidence of aging (manifested by loss of vigor or productivity, decreased health, or some other observable decline) of fruit tree varieties over practically relevant periods of time (read: hundreds of years). Can mutations potentially kill a variety over thousands or millions of years? Probably, they can, but this is a hypothetical question of zero practical relevance.


#43

I do agree with the point the above discussion is of no practical relevance in growing fruit trees.


#44

You did exactly right. i would add though with trees we are talking thousands of years here. So not really a factor for us to worry about.


#45

It’s extremely likely that the ability for us to directly reset those mutations is within the practical lifespan of most of the various varieties we’re interested in. Which also is theoretical but just as relevant. It mostly means if there’s a variety you like, grow a bunch of it so you increase your odds of clean genetics is improved.

It’s also worth noting that genetic accumulation of flaws isn’t why the vast majority of trees die. They don’t ‘die’, they are killed. Putting the genetics into a fresh root system is indistinguishable, aside from genetic testing, from rejuvenating the tree back to youth. Much of the aging process of the tree comes from physics, not genetics. Trees are hydraulic thermal pumps. Hormones are pulled by the forces of gravity, heat, and concentrations. ‘Maturity’ also involves the physical properties of the tree. So yes, if you reset all the ratios of trunk to root and remove the root mass, for practical definitions you have reset the tree physically. If you could then treat the genetics you had to correct the DNA for known virii, you could reset it entirely.

Or put shorter: It’s not that trees have lifespans it’s that our world collaborates to prevent trees from living longer. Errors just add up. Most of the damage is physical, not genetic.


#46

Anybody who knows genetics will not dispute that clones age and all cultivars eventually will die out. Nobody in the science community argues that this is not true. It is established science, not a theory. As far as a way to prolong it, you can to some degree, maybe?? Nobody can ever stop time, so even stored tissue cultures are going to be subject to the wrath of aging.


#47

As to the initial question:
In 1998, I saw what was probably a 40+ yr old grafted Illinois Everbearing tree at Les Wilmoth’s (NRNTN’s John Brittain’s mentor) place at Glendale KY. Huge… probably 35-40 ft tall, if not more… two men couldn’t have touched one another’s hands in trying to reach around the trunk.
Looked totally healthy to me…I was in awe of it. Certainly would have been a great ‘shade tree’ for any yard.
Les indicated that there’d been two, but they removed one because popcorn disease was so bad on it.


#48

glad to see the exchange of ideas resumed, although probably best to move it to another thread if @Botanical_Bryce feels it is way off original topic. .

anyway, while my views run counter to @Barkslip and @Richard, i don’t claim that my views are conclusive, since nobody knows everything(hey, even einstein and newton have been proven wrong about certain stuff they were cocksure about or were wagering on). There’s always that risk, that some time in the future some of us will be proven wrong. Much like how we think the folks hundreds of years ago were backward and clueless

now, the conclusion definitively brought up by @Barkslip and @Richard is that once a rooted airlayer from a tree is removed and replanted, then it reverts to the chronological equivalent of a young seedling, other than being able to bear fruit so much faster.

it is so hard for me to accept that juvenility is conferred by a simple removal from the mother plant. Also, you can’t be labeled juvenile AND considered mature at the same time, can you?

if you plant certain citrus from seed, you will realize that you have to wait many years before tree ‘gets old’ enough to start flowering and bearing fruit. Certain citrus from seed grow wicked 3" spines as juveniles, but will lose this trait as they age. An airlayer from a fruiting citrus will not produce spines, because, well, apparently it is only for youngsters.

a better elaboration would be to bring up extremes in the fruit-growing world. If anyone here had experience growing tropical stuff, you’d have realized that certain long-lived species have long gestation periods when planted from seed. Some longer than a decade, and some even longer. A legendary lychee tree reportedly took half a century to start blooming. The only way you could skip juvenile stage is if you airlayer that 50 yr old tree.

quoted below seems to bolster my argument, plus adding a tangible novelty with regards to age of roots and the value of grafting to younger rootstock. Ageing/senescence of a perennial tree is reportedly tangible, at least with avocados, but the good news is that it can be ameliorated or diluted by grafting to young rootstock. As implied by the report, taking an airlayer from that avocado tree equates to a clone as old as the mother tree-- not a rejuvenated one. I lifted it from this official FAO webpage.

Grafting is widely used because it is clonal. But graft takes about 10 years to fruit, sometimes more. It is apparent that the seedling rootstock imparts juvenility on th escion. Some tissue culturist know that shoots from an old tree as avocado, that has lost their capacity to regenerate, when grafted to a seedling, can revert to juvenile phase that responds to in vitro culture. This study is the first report of the influence of a seedling rootstock on imparting juvenility on the scion that in return results in delayed first fruiting. The prospects of reducing the juvenility period of a fruit tree into half, say 5-6 years in lanzones, means a tremendous commercial advantage in early and higher revenue. Ten lanzones seedlings planted in 1984 fruited after 21 years. Three plants from rooted cuttings planted in the same area fruited after 8 years while it seems that juvenility was overly extended in both sets, the relative difference is apparent. These trees were never fertilized, watered or pruned. Dr. Romulo Davide had 2 lanzones trees planted in 1959 that did not fruit for 30 years. |Rooting of cuttings is apparently the ideal propagation method for lanzones partly because it combines the efficiency and convenience of seedlings and grafting, and more importantly because it advances first fruiting and shortens the gestation period.

will post more stuff, just couldn’t find it at the moment.


#49

Hopefully Carbon-14 dating and dendrochronology services get more affordable. I so wish to have funds to finance central core(heartwood) testing of reportedly millennial trees still alive today, or those which recently died.


#50

Why do peach trees only live for 10-20 years?
A scion taken from such a peach tree at the end of its life will live another 10-20 years, am I not correct?
If this isn’t regeneration, what is the process involved?


#51

I don’t know much about woody plants but I do know bananas have been grown by cuttings for thousands of years. Even that process which should only create identical plants has resulted in unique cultivars. I personaly have observed plants have random juvenile reversion mainly cactus but also bananas. Cloned banana cultivars can revert even after decades of no reversion. Old tree collards have almost unviable cuttings but young cuttings propagated over and over have been around for at least 200 years. There was recently some research in DNA rejuvenation of certain plant species. I personally think the topic can go forever but I don’t believe the answer is one size fits all.


#52

Except for a lot of plants, like plum trees, the lifespan isnt hundreds and hundreds of years. Yet we have gages and other plums going back to the 1600s and further. I am pretty sure their mother trees would have died centuries ago.


#53

We need to be sure which topic we are talking about. Your question is perfectly fine. But you need to differentiate between the lifespan of a tree and what I called lifespan of the variety. The lifespan of a tree is strongly influenced by the environment.
I don’t know why especially peaches in my climate are so short lived. It probably has to do with cultural practices and pressure of different pathogenes.


#54

a scion taken from a declining peach tree will live another 10-20 years ad infinitum, if it is grafted to seedling rootstoc, but if you let it grow on its own roots, i have serious doubts, even in a sterile disease/pest-free environment.

as per study i posted earlier about avocados, grafting to young rootstoc ‘dilutes’ the age of old, ancient avocado scions from hundreds of years ago. The age of the roots seems to be the most critical in the equation. Roots seem to have this crude analogy to car engines. Electrical components are more durable, but with most cars, the engine wears out and gets old relatively quickly, so replacing it with a new one prolongs the car’s functional life. Even more intriguing is that young rootstoc also have hormonal effects on old avocado scions, such that it is impossible to perform tissue culture on the scions(which are just too old to respond to tissue culture), unless grafted to a young rootstoc first.


#55

You are right but the age of a tree doesn’t reach its potential lifespan because of environmental influences. But besides that Andrew refers to a biological clock which tetermines the absolute end of a variety. It then will no longer be able to live, not by grafting and everything.
Again I didn’t know about this before…


#56

I dont think there is any condition that would have let the parents of say reine claude de bavay just keep ticking…i just dont see an event where over a decade or so rhe world loses ashmeads kernal or mirabelle de metz due to a global senescence event where all clonal samples got old and died


#57

I am not sure that is right. You should be able to clone a peach variety until the lifespan of the variety is spent. I don’t know how long this will be for a peach. But it also should be a very long period of time.


#58

it is evidently a long time, since many supposedly ancient nectarine cultivars are still around and being propagated. But i have serious doubts about nectarines being propagated/grown on their own roots. They have to be grafted to young roots. The thing here is that the roots of an airlayer is as old as itself, whereas the root of a seedling is so much younger. This happens to be one of the reasons behind my assertions, that airlayers are just as old as the mother plant, and that it does not revert to a juvenile stage once removed from the tree.


#59

With some stamina we could try to test this thesis. Peaches and nectarines generally are hard to root from cuttings, it is possible though. One problem might be to get the needed “young” shoots from an old peach tree.
I am hesitant to try cause I don’t know an old tree worthy of propagation. I know two old peach trees. Those probably are seedlings and the fruit quality is nothing to speak of. I am lacking space for such an experiment. I will think about it.


#60

So a variety is found growing on its own roots from seed. It has desirable qualities and is grafted to rootstock to propagate it. Over time a sport is identified that has mutated. Is it more likely to occur in a variety that has only been propagated for twenty years or a variety that has been propagated for a hundred years? Is what we consider an exact replica of the mother tree really that exact? It seems sometimes that a variety splits, one source with a distinctly different set of characteristics. I wonder if one of the lines may have been replicated less and is therefore closer to the same as the mother tree? Is it possible that the scion and the mother tree are not quite as closely linked as we may think?