If I were to tissue culture a mature apple tree, would it already be past the juvenile phase and have it ready to flower as soon as it is large enough? Or would it be more likely to revert to its juvenile phase and I would have to grow it on for several years to fruit?
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It would act just like a baby tree planted from seed. Sorry, no shortcuts other than grafting a piece of that tree onto dwarfing rootstock.
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So hypothetically, if there was a particularly good apple that I can buy at the fruit shop, but plants/scions are not available for whatever reason, and I tissue cultured the apple stem so now have a small clone in a jar. I would have to grow it until it passes the juvenile stage?
Thank you, that is good to know!
i actually think that the long gestation periods of some tissue-cultures(of dicots) are due to absence of strong taproots of tissue-cultured clones, unlike seedlings which develop vigorous taproots.
always found it hard to explain my take on this, but will try(yet again): if the source of the tissue culture was taken from an already-fruiting tree, and if you were to let the tissue cultured specimen grow big enough to be able to provide budwood to graft onto seedling-grown rootstock, that budwood will flower and produce fruit way sooner when grafted to the seedling-grown rootstock(sooner than the rooted tissue-culture it was taken from–in identical growing conditions). And comparatively, will also produce fruit way sooner than if you were to get budwood from, say, a 6 month old seedling grafted to another 6 month old seedling-grown rootstock. Budwood from a 6 month old seedling grafted to another 6 month old seedling will essentially be just 6 months old. A budwood clone from, say, a 10 yr old(already-fruiting tree) grafted to a 6 month old seedling will be considerably more precocious, shaving off several years’ wait, especially if seedlings of the species have inherently long gestation periods if let to mature on their own with no mature grafts whatsoever.
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So if a pecan was tissue cultured and let’s say the pecan got to bearing size in 7-8 years - I’m going to assume it will produce pecans vs. the typical 15-20 years from a seed. That is correct, right?
Dax
I think it depends on which method of tissue culture. Some revert the plants to a seed-like state and others do not.
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Is that accomplished by chemical additives in the tissue culture used to influence gene expression?
Maybe, I think somatic embryogenesis produces mutations but I’m just going off of what I read when I wanted to micropropagate figs (it is very time consuming and technical and didn’t work out for me). Somatic embryogenisis is more efficient in removing viruses and can produce many plants quickly, but using shoots or the apical meristem does not revert plants to a juvenile state and has fewer mutations.
Everything you’re trying to do is better accomplished by using a dwarfing rootstock like Bud.9, which will fruit the second year. Tissue culture in apples is mainly limited to rootstocks that do not produce well in the stoolbed. Unfortunately, they still have problems elongating once planted
This very well may be true, but I don’t understand why? Is it the hormone level? It has been proven time and again that trees know their clonal age. Clonal age of anything can be tested. Your example both are the same clonal age, so not sure why what you say would happen? The best example of clonal age was demonstrated around 1990 when a very popular bamboo became 120 years old and flowered. Bamboo dies after flowering. And thousands of clones of this bamboo across the USA began flowering and dying. Clones not big enough to flower, flowered when they became big enough. All died.
Also the case of Aspens loosing the ability to sexually reproduce due to DNA damage from their clonal age. Clonal age can be measured by the mutations in the DNA due to aging.
that is a great example of proving that age does get conferred to clones, Bamboos, like bananas(which ‘die’ after bearing fruit), are monocots though, so people who believe in eternal life or reversion to juvenility of dicot perennials will have reason to argue. Incidentally, and intriguingly— if bamboos don’t breed true by seed, then every bamboo cultivar is doomed to extinction, as all the succeeding generations of bamboo from seed will have a different dna(due to meiosis of flowering) from previous and subsequent generations. Not many people know that bamboo can be propagated from seed, primarily because it takes so long for bamboo clones to flower and fruit. Moreover, we also tend to use human lifespans as the ‘reference’ for longevity, but plants know not of this and will follow their own. Some like determinate tomatoes will die within a year or so, while indeterminate tomatoes will regress and ultimately die after several years. Some people say indeterminate tomatoes will live forever if grown in disease-free environments, and while i wish that to be true(hey, who wouldn’t want that?), i think ageing is real and unstoppable and those tomato vines will ultimately regress and die. And seriously doubt if their airlayers or tissue-cultured clones will resume juvenility as if grown from seed and assume the same lifespans or productivity rates of seedling-grown tomatoes.
definitely a hormone level, plus true age level This thread is about tissue-culture, and some might not think this true, but grafting is in fact a type of tissue culture, where there is an interplay of hormones between scion and rootstock which rejuvenate budwood but also keep its true age/maturity level. Our tissue-culture technology seems to be still at an infancy. From what have posted previously at several similar threads: very old avocado stem tissue cannot be coaxed to grow roots with hormonally-induced(by humans) tissue-culture, unless grafted to juvenile rootstock first. Which means young rootstock has to ‘feed’ very old budwood with still unknown substances before it can undergo somatic development(in this case-- root development). but not reverting it to an absolute juvenile avocado wherein you’d have to wait 6 years or more before the clone starts blooming/fruiting–say-- if you graft a bud from the clone to a rootstock that is well-developed, as opposed to growing the clone on its own roots(feeble adventitious roots)
and quoting myself, i forgot to mention that conversely-- budwood from a 6 month old seedling will continue to be a juvenile even when grafted to mature(already fruit-bearing) rootstock of the same clone. Japanese researchers have done this on citrus(which bear true to seed), in the hopes that grafting seedlings to old rootstock would result in early maturity of seedling budwood, but unfortunately not. Will post the study once i find it.
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I have no experience with tissue culture. But, I know the leaf cuttings from a MATURE ivy plant…the ones with no indentions…have not reverted in the past 12 years I’ve grown them from cuttings.
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LOL! yes, well 98% die, they have developed techniques to try and save the bamboo. It is possible to save 2 out of 100 tries, sometimes more, in nature 2% live. . Very good info on what we have observed in grafting and tissue cultures. The fig community complains about the length of time TC’s take to grow. We have found wood to be thin, spindly, after some pruning it appears to grow out of it, or dies in some cases, as the tree seems to get into trouble easier than a rooted cuttings. Rooted cuttings from the TC plant seem like any other cutting.
Because of alpha, beta, and gamma radiation their is no escaping clonal age. Stone gives off more radiation than organic building materials and can result in more mutations, say if you work in the Capital building. Presidents seem to greatly age after office! 
Another example of clonal aging.
i successfully rooted a honey jar jujube from a lateral which died on its second year, apparently due to weak root formation or the specimen itself assuming its true age. As many of us think of it-- the age of trees is a great deal determined by the age of their roots. So budwood from hj grafted to a younger rootstock seems to carry on with life(much like a 10 yr old car with a rattly old engine will start purring again with new engine), whereas an hj stem on its own roots would have roots as old as the original seedling the hj cultivar was grown from(of course that was just one specimen, so my hypothesis might not be accurate, apart from actually wishing to be false) I currently have another jujube cultivar on its own roots which seems to have produced abundant roots despite being what seems to be also a lateral stem, which i find extremely intriguing. It is a case-study which elicits so much curiosity and value.
am thinking this cultivar(sihong) is a much younger cultivar, since, using my old wood analogy with avocados, stems from aged clones will have poor root formation compared to younger ones. Incidentally, the same applies to citrus as well, which is why citrus airlayers don’t grow fast and will have poor root formation. Of course, it is still possible that sihong might be genetically longer-lived than hj, so even if is so much older as a cultivar, its clones may still outlive clones of younger cultivars.
tissue culture is not as naturally occurring in nature as cuttings are. Quite likely that the hormones used for tissue culture(even though successful in getting to root) results in ‘damaged goods’. You have the clone alright, but that does not mean it is going to perform, since it was an artificial attempt.
anyone who’s familiar with creeping figs(Ficus pumila) is very well aware that the genus has a tendency to take root well above the ground, and will grow from cuttings/inarch naturally with no extraneous hormones/chemicals.
Different plants respond differently to tissue culture; all those flowers and plants you see in flats at Home Depot are TC, and most blueberries grown commercially are TC. This is in order to rapidly propagate them in a disease-free environment. Even rural parts of Africa have tissue culture labs set up for propagating banana seedlings. The bananas from TC produce quicker and heavier than their non-TC counterparts, but only because the viruses and disease inherently passed on by vegetatively propagating them are absent in the TC plantlets.
The apple scion grafted onto dwarfing rootstock fruits earlier because the tree reaches maturity faster. It has nothing to do with the age of the tree that the leaf that was cultured came from, as the leaf always comes from the current season’s growth. It may spend a year in vitro being divided again and again before the hormone is switched to induce rooting.
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at some point, tc is probably the only way of propagating certain clones of bananas(and many other disease-prone species), wherein disease-free cultivars will be secured and propagated in sterile environments, and released to farms until subsequent pups get afflicted with lethal diseases. The lakatan cultivar(which imo is the banana connoisseur’s choice), may just be treated as an annual or biennial some day, unless some biotech company produces one that is resistant to bunchy-top.
glad that hormonal induction to micropropagate bananas and many other fragile species have been perfected without compromising the explants’ progeny. Perhaps someone will come up with protocols for certain figs and other inscrutable species, which seem to suffer from the botanical version of 'roid-rage
i beg to disagree with this, if you clone a 2-month-old apple-seedling’s tissue and graft to dwarfing rootstock or any other precocity-inducing rootstock, i’d find it hard to believe that that tissue-clone will behave like it was taken from a mature tree.
The first TC fig plants available grew so weird someone swore up and down that the BT they bought at a local nursery was a mislabeled rare form of fig. There used to be a picture on Agristarts site of a tree 10’x10’ with probably a hundred suckers and not a single fruit.
Later on they seemed to behave more normal, although places like Wellspring started to root microcuttings on their own, I got a Petite Negri microcutting with a couple figs forming on a 3" plant so what people think is a TC fig might not be, but Olympian I’m sure was a TC and seemed normal too.
glad some of those tc figs did well for you. Figs are some of the most valuable, and sadly-- also some of the most under-appreciated fruit species around. I sometimes suspect that the runty kadota’s have been growing are tc duds.
did you just say your 3-inch tall clone is bearing figs?! That’s pretty cool, just when i thought my 5" tall fruit-bearing honey jar jujube(grafted low) was impressive! We should probably start a thread about fruit-bearing micro-trees.
That PN only had a few roots when I got it, I immediately broke the figs off because it was weak. It still ended up dying by the next spring after a fig bud mite infestation and extra cold winter.
Have you tried hard pruning the Kadotas?
unfortunately there weren’t enough branches to prune-- the specimens were super runty. Alive and growing, but painfully slow and uneventful