I was reading a thread earlier discussing seed of citrus was geneticly affected by rootstock. It was said that seeds germinated from meyers lemon more closly resembling the root stock. One said it was affected by rootstock buy genes which had made its way through scion to the flower. I have a hard time understanding this. The way I see it is the original genes of the parents of the meyers lemon are still present in a meyers lemon clone or scion. So the seeds that come up has the variablity of producing plants with caracteristics of the both parents, itself or , totaly different characteristics. Not related to the genes of the rootstock but from the genes present in the scion. Also, It was stated that a cutting produced more seeds which which more closly resembled the parent because it was not infuenced buy stock. Could this be due to more vigor not genes. I collect Acers so I'm tring to understand how rootstock could directly infuence a scions genes. A.***. are grafted on A.palm. Seeds are not hybrids? Also use of interstocks. Finally; seeds are a product of genes present in plant/clone and genes present in pollen which pollenates? Thanks Elton
A recent scientific study appears to prove the possibility of genetic transfer between rootstock and scion. Here is a link to an article discussing the findings: Unintentional genetic engineering - grafted plants trade genes I have seen various claims with regard to Japanese maples in this respect. For example: Red versions of green cultivars were created asexually by repeated grafting over several generations onto certain red rootstocks; and variegated cultivars are less likely to "revert" to a non variegated form if grafted onto variegated rootstocks. I have no way of knowing if these claims are true but they were previously posted in these forums by a seemingly reliable source and not disputed as far as I am aware. By the way I am not a biologist or anything, just an interested amateur maple collector, so cannot claim to be an authority on the subject. It's just something I've read up on a little out of a similar curiosity to your own. Hopefully someone can supply more information on the subject.
If genetic transfer is the case and the stock genes are present inside the clone. If a cutting or layer take from the grafted clone, which now has stock genes present, would the cutting or layer not also carry those same genes. I don't know if possibily chemical differences may have any controling factor with genes selected to be recessive.
Interesting link, thanks Maf. The authors do find a certain locality to the transfer, which in itself is puzzling as it suggests some sort of damping mechanism related to propagation over distance. Based on some of the anecdotal evidence we've seen in Maples it's certainly easy to speculate that the damping is different in different species. Perhaps less effective in Citrus or Maples but very sharply defined in some other less polymorphic species? If we hypothesize genetic drift from the graft, that means every maple cultivar is nothing but a grex... So the only way to propagate successfully would be what: to clone rootstock from the scion in a petri dish (is this even possible?) and then graft to scion to it's genetically identical base? -E
No expert here but may I offer an opinion. The Scion would contain both a primary or apical meristem which is responsible for shoot growth and secondary meristems which cause growth in the cambium layer. The root stock would only be a suppler of secondary meristem tissue. While there might be some swap of genes at the graft fusion what would the final result be at the apical meristem. Would the supply of nutrients affect the apical meristem enough to result in any noticeable change???? I would think the greatest affect would be to see an increase in the growth rate if a slow growing variety of tree was grafted to a faster growing rootstock. The rootstock is simply supplying nutrients to the scion and the genetic makeup of the scion would be the dominate factor in the final product. I think Emory has hit it squarely on the head about the genetic drift. Has anyone seen enough variation occurring through grafting that new varieties are being produced. If so name one???? I'm always game to add to my collection....... It is possible to micropropagate Japanese Maples through tissue culture. Would it not be just as easy to root cuttings to achieve nearly the same results. Hope there is more discussion on this matter.......... Lee
Indeed an interested subject, mainly for plant geneticists (of which I do not hink we have many contributing to the forum ;o)), I reckon. We, amateurs, can just observe and comment. Observations from propagators could give good insight since those guys may graft hundreds of plants of the same cultivar and, if the scions come from the some mother plant, the rootstocks are all different. So they are well placed to tell if they have seen noticeable differences in their grafted plants which could be attributed to rootstock influence. Gomero
I believe Mr. Shep made the post about creating a red cultivar by grafting a green cultivar on red rootstock. The difference, as I recall, is that multiple successive generations were grafted onto red rootstock, such that scions taken from that original plant were then grafted onto red rootstock, then scions from THOSE plants were grafted onto red rootstock again, etc. etc. The eventual outcome after a number of generations was a red plant. Conversely, propogation methods employed today typically consist of a "mother plant" that is used for scion production, and each generation of plants produced from that mother plant is grafted onto fresh rootstock each time, so there is normally only one generation from mother plant to grafted plant. This may not be enough to induce the radical changes Mr. Shep saw in his experiment with successivly grafted generations of plants.
Indeed, that was the process I was referring to. Iirc it required eleven successive generations of such grafting to create the red version of the green cultivar, Seiryu in this case, that was stable enough to be grafted back onto green rootstock and remain red. The variety of rootstock, I believe, was specially selected for this experiment, ie not just any old red seedling. Once you accept the scientific possibility of limited transfer of genetic material between rootstock and scion, such an incremental change caused by grafting successive generations onto a selected variety of rootstock does not seem that far fetched. If these methods, or similar, are used by professional maple propogaters they might be considered "trade secrets" and not a subject they would discuss in an open forum such as this. As an aside, I often see examples of the same cultivar that look slightly different to each other, and wonder if different rootstocks may be influencing the appearance. I know many other factors could be in play, such as different mother plants, but I wonder all the same.
There does seem to be some variability. For example, I was comparing notes with another maple addict and we both have 'Hogyoku' with mediocre fall color - not the acclaimed "pumpkin" orange. Is this cultural, climate, or the result of so many scions being grafted onto rather ordinary understock over the generations? We will never know the answers until someone with $$$ invests in REAL scientific research about these and other questions on this genus. Has anyone tried to get Bill Gates addicted to maples, per chance?
I haven't spent enough time grafting maples to confirm my suspicions that gene swap may be possible. However, I have seen enough evidence from cultivars coming in from oregon that show some variability in color. In this case a certain well known nursery produces large quantities of crimson queen maples, and most of them exhibit poor color retention compared to some crimson queens coming from some other nurseries. I am currently observing this closer after comparing the two "strains" side by side in the same growing conditions. I can't say for sure that gene swap is the cause, but I can say that there are distinct color variations amongst groups of same named cultivars (with apparently the same leaf shape). In fact I have seen this with several red cultivars, and I am pretty confident that it is not because there was a mix up of naming or due from selected seedlings getting named improperly, due to the same leaf shape and relative habit.
It can not be uncommon for a particular rootstock to influence plant characteristics such as growthrate, spring leafout, fall folage, or other visual differences. For instance a chosen cultivar was selected. Two different rootstocks had been selected; one of which show extreme clay and drought tolerance, the other suitable in low wet areas. The choosen cultivar has compatabilities with both stocks and will most likely be happy where the roots are happy. When you put the tree grafted onto water loving stock in the hard dry clay it will most likley show visiable changes. vise>ersa... One reason why I chose ***. maple forum is because of the history of japonese propogators date well over 2000 years ago. Some trees still in cultivation surving hundreds of years being grafted on possibly hundreds of different rootstocks.....
I'll come out of veritable hiding for a quick reply. I have not looked in the UBC forums for a few months. Received a phone call last evening in regards to this thread. I must admit I was not wanting to come back in to reiterate and expand on what has been done in the past. I like the article on tobacco. Today we do have a better ability to measure if and where in the plant that movement has occurred. In years past all we could do is let what we see from these plants dictate to us if phenotypic changes had occurred or not based on a series of progeny year after for year for a number of years. Citrus people used various rootstocks to induce cold tolerance into their production trees. It was not immediate that some Lemons and Oranges became more cold tolerant over night but over time there was some cold resistance built into some of those cultivars that seemingly was not shown to be so prevalent in colder temperatures before. Thanks in most part to the rootstock parent or rootstock parents. We know in Pomes (Apples and Pears) what dwarfing rootstocks have done over time to scale down standard trees in height and in overall spread. There are historical records that show beyond any doubt that rootstocks can and do influence a variety of plants. The question that has evaded us is how can we prove genetically that the rootstock has influenced the scion parent and now we have better techniques to use to help us along that we did not have access to back in the 70's, 80's and 90's. Now we can show that although we can measure change in chloroplast DNA, that chromosomal DNA has not yet been changed yet, or the induced recessive traits are being sloughed off, present during mitosis, in the gene prior to meiosis as one example. I still think the E.W. Sinnott view on what causes variegation in Citrus may still hold truest from cytoplasmic DNA, that the devoid green color is not solely due to "code" errors in plastid functions but more so due to chemical and perhaps genetic changes in cytoplasm that the plastids reside in. Then again we are still not sure how a plant can yield more than one chlorophyll internally anyway such as a Lemon or even a variegated Maple or a Camellia having both chlorophyll a and chlorophyll b in their systems. There probably are more different chlorophylls that we have not isolated and identified yet but to some of us that have seen the layered look of some of the variegated leaves of highly variegated Citrus, it makes us wonder if there was been a mutation that has occurred to yield the dark green and light green shades as well as the dark yellow, almost golden colored yellow and the cream to almost white colored yellow in the same leaf. Now we are into what has intrigued people over time about the Goshiki, five colored, Maples such as Goshiki shidare, Goshiki kotohime and Goshiki kaede. Why is it that we do not see the five colors any more in these plants? We felt over time that continually grafting these cultivars onto non select green seedling rootstocks would cause these Maples to become more green and bronze in color rather than be two-toned green with pink or red and cream and white. We've seemed to have lost much of the cream and white that should be pronounced in these plants in the Spring. Even the red form of Aka kotohime does not have five colors, the most we will see is three - green, red and light green. The same has been true in more recent years with the Beni kotohime, of which many current day plants sold as Goshiki kotohime either have been reduced to being now or several were Beni kotohime all along with the green, pink and lighter shade of green. The lighter shade of green may confuse us thinking that it will fade to yellow but it is not a true yellow in the same coloring of a true Goshiki, any of three mentioned above. We rarely see the cream and yellow in the Goshiki shidare any more. Some of us feel this was due to us continually propagating this Maple onto green seedling rootstock instead of a select form of variegated rootstock such as Kagero or even better yet the old form Kingsville nursery or Burbank nursery Roseomarginatum. Whip (wood to wood branch) grafts in Maples has been done for many years by the Japanese but grafting scionwood onto rootstocks really was in its infancy worldwide as little ago as the 60's and 70's and then only by very select Maple propagators. I never wrote that I was against grafting, there are several Maple cultivars that would have perished had they not been grafted years ago. Filigree and Silver Lace would have surely died out in the mid 70's and early 80's had they not been grafted. We already know that Acer pentaphyllum would have died out back in the teens had it not been grafted to hold it over until a more universal rootstock came along for that particular Maple. Jim
This is a marvelous topic (thank you, Elton) & genetic questions like this fascinate me so I have to read academic monographs and/or talk with very bright friends (like mr shep). The reddening 'Seiryu' information that mr shep put on this forum in the past and which maf & Kaitain rightly recapped for us is downright amazing. A lot of work has been done in academia on fruit & citrus and one can access some of these works on Google (like the great link maf put into his post), but as Kaitain says because there is no money in maples for academia there has been no genetic work done there on our beloved maples although some of our gifted nursery people have vast working knowledge in expressed genetics. I have talked this subject with academic friends and am struck with how little is definitively known in plant genetics. On this specific topic it is simply not known if rootstock chemistry changes nuclear chromosomal, mitochondrial or chloroplastic DNA. It is "thought" that hormones like cytokinin and/or brasinolide affect or simulate genetic signals as growth regulators as they move up thru the rootstock from the roots into the scion and/or whether RNA moving up from the rootstock into the scion is showing effect by regulating gene activity. I was talking with a fine academic today who did the definitive studies on the various effects of 7 different rootstocks on Gala apple scion & the 1 fact he told me they do KNOW is that the different rootstock must be continuously applied to the Gala scion to get the changes they were modelling because as soon as they grafted the Gala scion back onto a Gala rootstock, the changes they had seen disappeared. I continue to experience this incredible lack of genetics knowledge in my pursuit of maple witches broom genetics on which there is no work anywhere. As I read and learn more about this rootstock/scion chemistry I will be glad to share what I learn in understandable English and I hope others will share their knowledge because this is exciting.
I do believe we can change the genetic composition of the scion parent plant by way of using a rootstock to do it. The dilemma has been which rootstock to use to help us along. In the olden days of grafted Maples palmatum Aureum, the same plant as shown in the Vertrees second edition book was the rootstock of choice to use for both red and green scionwood grafts in very select nurseries for many years. The feeling was that Aureum was a neutral rootstock in that the rootstock did not change the coloring of the green scion parent and did not lead to reducing the color of the red scion parent. In other words in the case of a shojo group red like Inaba shidare was and still is in some collections and perhaps an arboretum or a botanical garden or two, we would not see the grafted progeny become an atropurpureum over time as readily by using Aureum as our rootstock for grafting and budding. Even seedlings grown from the shojo group red Inaba shidare stayed pretty much shojo. This was important to a few people that worked with this Maple as a few years later many Inaba shidare were grafted onto green seedling rootstock which had a greater propensity to yield a number of atropurpureum seedlings. It stands to reason that a mixed blood (red and green in its background) can yield wood that may not all be identical progeny when grafted onto green seedlings. We assume the wood from an Inaba shidare or a Crimson Queen will look the same when grafted onto green seedling rootstock but many times the batch group plants may and usually do not look the same for color as the growing season progresses. Just like in seedlings we can see variance in the reds for color in that some plants will show more green coloring either as an overtone or an undertone than others do but we also can see more of these individuals have more green in the centers of the lobes which may not be undertone at all but may indeed be a blending of the red and green colors. A modifying effect if you will which will only become more pronounced over time in progeny when we take wood that have the modifier color in their systems and continue to graft them onto non select green seedlings. This is precisely why in some cultivars we do not assume that all wood on a Crimson Queen will yield grafted offspring that will all be alike to its parent. We need to be more selective in which wood we take for grafting, note which branches have varying color from the others on the tree and only select wood for grafting or budding that more closely matches the color we want our grafted youngsters to be like from that Maple. Now that many to most of our once was shojo group red Inaba shidare have become atropurpureums that we should see much more evidence of greening in the leaves from various grafted offspring than we ever saw from the shojo group red Inaba shidare. Either we take wood from an old shojo group plant to graft onto a green seedling one time or we only take cuttings and root them to perpetuate the original color for this Maple. It is too late now to go back in and try to return this Maple back to being a shojo group red by using a red rootstock to do it with so many current day plants being an atropurpureum but we can create a nigrum form of Inaba shidare in the process of our grafting. This scenario is not so bad a thing as the nigrum group Inaba shidare may be a better colored Maple in many more areas than the atropurpureum form plants have been. In other words the red color retention should last longer and show less bronzing with less green coloration in the leaves if we compare a nigrum form red to an atropurpureum form red in this case. Compare an old Ever Red that is perhaps 25 years old to a batch produced five gallon sometime and wonder why the five gallon pales in color expression year round to the old plant over time. Take the 25 year plant and use it as your check plant and then compare the seven year old to it for the next five years and tell me or ask yourself if the then to be 12 year old ever looked as rich in red color during the growing season as the specimen plant does or perhaps did, if it is still alive. We have overlooked the fact that today we want to graft fast and furious but we have also lost a lot of our quality control (color retention) in our Maple cultivars because of it. We do not need a genetic read out to know that our wood selection process probably has lead to faster change in these plants than a green seedling rootstock has. We do not select our best wood for grafting. Some nurseries take any wood on the mother plant, no matter if the wood has Tight Bark showing or not. This is not a good sign for the future at all as all we do is advance the likelihood of more and more plants having Tight Bark instead of taking unaffected wood and lessening the affects of it in our Maples. Today we even have Tight Bark symptoms seen in one and two year old green seedlings we want to use as a rootstock, which in my mind, will be the death knell for a host of cultivars, especially for the known Verticillium susceptible cultivars, if we do not immediately clean up our act from a propagators standpoint. A well known nurseryman in the Pacific Northwest is working on just this. He is trying to outrun Tight Bark by raiding new wood for Spring and Summer grafting. As long as his rootstocks are free of Tight Bark, in time he will succeed in limiting the affects of Tight Bark in his plants. So that once they get up to about 15 years old or more and start to go stagnant we may then see the overall effects of Tight Bark. From then on selective pruning and perhaps some nutrient accompany will keep the plants alive longer in the ground. Whereas many other plants from other growers may not ever get up to the 15 years and older for age. There is no funding for that, just a conscientious nurseryman that knows what it will take to see these plants more likely become adult plants for people. No one has been able to guarantee we will end up with a mature Maple yet and someone it seems is working on it. There is a nursery or two in Holland that may be working on it also. My hat is off to all of them. The genetic equation is not very well known but we do have other plants such as Citrus that have had much more scientific work done on them. Some Hilgardia articles back in the mid to late 20's and 30's produced by the California Experimental Station at Riverside are still considered light years ahead of their time. The works of Halma and Haas in regards to how rootstocks affect scion Citrus still may be felt to be a treatise on the subject. The University of California considered some of these works and the offshoot reference books from Walton B. Sinclair on the Orange, Grapefruit and the Lemon unparalleled in their scope. I feel they still are, this many years later. The Biochemistry and Physiology of the Lemon and other Citrus Fruits book from Sinclair is second to none on the subject in my opinion. Go to Plant Physiology.org and use a keyword author search on Haas, Halma, Bartholomew and Sinclair and see what you come up with for the effects of a rootstock on Citrus trees and on Citrus fruit. While you are at it do a keyword search on Maples and then locate and read some of the European, Japanese and more recent Chinese studies on Maples. Jim
Jim, You are a veritable treasure-trove of information! Thank you so much for sharing your vast experience with us newbies. Truly fascinating!
I would also like to thank mr.shep for his contribution to this thread and agree with katsura, K4 and others that this is a fascinating topic worthy of continued discussion, and hope that others may have more information they would like to share. My own knowledge of genetics and biology is superficial at best; I am having to learn the meaning of new words to fully understand some of what is being said here and in the tobacco article I referenced above. If I may precis what I think I have learned of the subject, the key seems to be that the genes that are traded between rootstock and scion (or at least those that have been shown to be traded) are limited to chloroplast DNA, which is separate from the main DNA of the plant. Since the chloroplasts contain the light absorbing pigments, such as chlorophyl and carotonoids, it can easily be seen how they affected the colour of the reddened 'Seiryu' without, as far as I am aware, affecting leaf shape or branch structure. Going back to the mention of seeds of grafted plants in Elton's original post: Most flowering plants inherit chloroplasts only from the female parent, so a grafted maple could pass on rootstock genes in the chloroplast via its seeds, but not via its pollen. As for telling the difference between shojo, atropurpureum and nigrum colouring in 'Inaba shidare', depending on rootstock, it is hard for me to know exactly what colour a shojo should be, having only seen specimens that are more than likely grafted. My understanding is that shojo is the darkest group, almost a black red when opening, but I would one day like to see these colours (shojo, nigrum, atropurpureum, nomura, rubrum) explicitly defined; the maple books I have read are not much help in this respect. I can say that the 'Inaba shidare' I bought from Batsford arboretum about 9 or 10 years ago is darker than the next one I bought from a mainstream garden centre about 6 or 7 years ago. Whether that means it is from a better mother plant or not I do not know, but it would be nice to think the people at Batsford did their own grafting from old trees in the arboretum.
This is all very fascinating and brings up some points I had not considered before. Pardon my ignorance but could you explain in greater detail what you mean by tight bark. Thanks Guy
Good to hear from you again Jim. I was getting a little worried about ya. I think Jim has already gone into some detail somewhere in the forum regarding tight bark...I would suggest trying a search for it if you are interested for a more detailed response (unless he wants to come give another lesson). However, here is the skinny: My understanding is that it is a bacterial or fungal canker-like "disease" that spreads on the stems of some maples. I say "disease" because I don't know if that is the best description. It is commonly seen on dissectums and appears as small discolored bumps on the stems. Some folks say it is only sunburn, but I think there is more to it than that. Sun burn may be a catalyst to the spread, but I've seen Crimson Queens 25 ft apart...one in the shade is covered in it and probably will not survive a couple of more years, the one in the more sun seems to be clean and vigorously growing. As Jim will mention it isn't the tight bark alone that can severely hurt a tree, it is the tight bark coupled with verticillium and/or other pathogens that will slowly weaken a tree until it perhaps dies on us.
Re: O. T. Reds and Tight Bark Inaba shidare can exist in all five groups of reds - shojo, nigrum, atropurpureum, rubrum and even nomura. We tend to want to give any new colored Maple a new name, even when it existed before as a form of an older Maple. Even Red Filigree Lace can exist as all five forms but to my knowledge only the shojo, nigrum, atropurpureum and the rubrum forms have existed. I'd love to see a nomura form of Red Filigree Lace but I may not live long enough to see one. The original Red Filigree Lace plant sent to Mr. Goddard from Jean Iseli was a black red shojo group red. Years later Bob Baltzer in Oregon was credited by some people for originating the rubrum form. Unfortunately the name for this Maple, given the name by another nurseryman, already existed in some circles in the nursery trade as Ruby Lace. In fact Don Kleim had exclusive rights to Ruby Lace soon after William Goddard got his plant from Jean Iseli which was purported to be a sister seedling to Red Filigree Lace. Well, the old Ruby Lace was a nigrum form dissectum. The newer Ruby Lace is a rubrum form dissectum. Only the second Ruby Lace more closely resembles the Red Filigree Lace, while the former Ruby Lace was felt to be more of an improved 9-lobed Ever Red. The red dissectums have been troubling to learn for many years. A few mistakes have been made along the way when some people wanted to call a nigrum form of Inaba shidare an Oregon Garnet when the original Oregon Garnet is not even remotely related to the great Esveld Garnet Maple. Atropurpureum is a major headache as years ago even Wada's Nigrum was felt to be an atropurpureum by people that never had seen the Maple. Thus at one time there was a Maple called atropurpureum Nigrum. The crazy thing is that in Europe there was a Maple that probably should have been called atropurpureum Nigrum but the Wada plant was a Nigrum form all the way, not a black purple red but a richly colored purple red. Even my Superbum does not quite fit the profile of the writings on that Maple. I still feel that Esveld's Attraction probably should have been given that name as it surely is not the same Maple in color as mine is. Even through the wood for my plant originally came from Europe if we want to consider England as part of Europe. The reason why some of us came up with the shojo, nigrum, atropurpureum, rubrum and nomura group names was to help us along to know what the Maples were when we saw them when grown elsewhere in the ground. If we knew which Maples were a shojo to us we could better spot a Shojo Maple when we saw it somewhere else. The groupings have not ever been published. I am sure that there are some people that feel I am "nuts" but it does help me when I visit them and see their Maples as opposed to them knowing what we have when they see supposedly the same Maple they have. Mr. Vertrees did a great thing to list Maples by name in their prospective groups such as palmate, deeply divided, dissectum, linearilobum, variegated and so on. It was up to us to know when someone mentioned a Maple by name which group it resided in. Say the name Sotoyama and I knew it was a green dissectum, thanks to the groupings that Mr. Vertrees had, even if the Maple was listed as a synonym name for another Maple. Sotoyama could very well be the Japanese equivalent plant for the European Ornatum. The two Maples do not turn the same Fall color, one has golden tones with some red splashes, the other can have allover scarlet to crimson tones in some areas in some years but one is a green Maple and the other is a red dissectum. Even when both start out red in the Spring. The old line thinking was that a red dissectum had to start out red in the Spring and turn red in the Fall. Even the deeply divided Maple Azuma murasaki can start out red in the Spring and be golden tones with some red splashes in the Fall. I've always felt Otto's dissectum was a green Maple even though it starts out a rust red in the Spring. I've never seen one turn red in the Fall but I've seen some glorious orange tones in the Fall from our plant in some years. The leaf shape is almost identical to Ao shidare, a green dissectum. Could Otto's be a form of Ao shidare? I've felt it is and still do. I cannot fault people that feel that Otto's is a red dissectum but it does not turn allover scarlet in the Fall but in the right location, in the right setting it just might do it and probably has back in Pennsylvania and perhaps in northern Oregon as well but in central to southern Oregon it will turn golden to orange tones in the Fall. Talon might see scarlet Fall color in Gaston or Andre in Boring but Greer and Baltzer won't in and near Eugene or will Munn in Salem. Tight Bark is a bacterium. Will not kill a Maple by itself but can be lethal in conjunction with Verticillium alboatrum to a Maple that goes stagnant, no longer producing vigorous new growth. Dieback is such that more old growth is killed off quicker than the tree can replenish itself with enough new growth to sustain itself. In a matter of three years the Maple is usually killed off. The quick decline form of Verticillium is the most lethal to palmatum type Maples. It does not need Tight Bark to help it along. It still is the number one killer of all juvenile Maples all by itself. Generally is already in the Maples system via propagation. The old stock plant that we got wood from may only show signs of alboatrum but in juvenile plants we tend to only see the affects of quick decline. Here today and dead the next, about that quick once we see the terminal tips wilt and the leaves shrivel. With Tight Bark and alboatrum we have some time to do something about it. May not ever correct the condition but we can help the plant better adapt to that condition with some help from us if we do not wait too long. A hard prune and a nutrient boost usually but not always helps the plant out. Some plants will further their decline no matter what we do and the thread on Red Filigree Lace of my old plant will serve as proof. You can see alboatrum in the killed off shoots but it was Tight Bark that killed the tips of those shoots first. It only took three years to decimate what was a real nice specimen plant into nothingness. Tight Bark exists as a dry lesion. What looks to be sunburning to the wood may be Tight Bark instead if we look closely at the wood to separate colored streaks seen in the wood as opposed to lesions on the wood. Jim
Thanks for sharing mr.shep, I always find your information fascinating. There are not many people with your breadth and depth of knowledge of Japanese maples who would be willing to put that knowledge in the public domain like this. If you ever decide to publish that book I will be waiting in line to buy it.
Yes many thanks for the follow up information. From reading through this thread it would seem that the initial discussed problem of the rootstock effecting the scion over successive propagation generations & tight bark may require opposite practices to overcome! It would seem that to lessen the effects of rootstock modification you would be better to plant a stock plant and always return to this plant for scion material rather than take wood of successive generations of plants that you are producing. Tight bark problems on the other hand would seems to be compounded by using old stock plants & helped by taking scion wood from new young generations of plants. Over the last 10 years I would say that more & more scion wood has been taken from production crops rather than stock plants as was more common in the past. Several reasons being the market demand for these plants, less land tied up with stock blocks & the fact that generally grafting takes are higher when the correct kind of wood is taken from vigorously growing "production trees".
Re: O.T. Tight Bark "It would seem that to lessen the effects of rootstock modification you would be better to plant a stock plant and always return to this plant for scion material rather than take wood of successive generations of plants that you are producing." For better quality control of the cultivar, yes this practice has been rather widespread in the industry. I must admit I am turned off going into a nursery and not seeing any viable stock plants on location. It was the stock plants from which wood was gathered from is what I wanted to see much more than a few one to five gallons that I was not sure were ever propagated at or by that nursery. Sometimes with certain cultivars the stock plant may only be one Maple, more likely 20 years and older in age with select wood taken from that plant for grafting and perhaps later in the year for budding. "Tight bark problems on the other hand would seems to be compounded by using old stock plants & helped by taking scion wood from new young generations of plants." Many of the old stock plants that still show some vigor in the new shoots are not so much the problem. The issue is much more problematic with juvenile plants that are showing signs of Tight Bark that we take wood from to use as grafting material. Tight Bark spreads faster on a younger plant once it loses its vigor than an old plant that has learned to live with the bacterium for a few years. Not all Maples that show Tight Bark are a problem for us but when we graft infested wood onto a cultivar that is known for having issues with Verticillium alboatrum that we speed up the likelihood that other progeny will have Tight Bark as well. One thing we can certainly expect is dieback once the young plant becomes overly stressed or after the plant has experienced a series of stresses. All we do is exacerbate the problem even more when we use any seedling or rooted cutting for a rootstock that is showing any signs of Tight Bark on the plant for use as a rootstock [What should have been vigor in the rootstock has been decimated by the Tight Bark. Lift the rootstocks out of the containers and see how much or in these cases what little root shoot development we have with the Tight Bark infested rootstocks]. We can take wood on one side of the tree in which Tight Bark has not spread to yet and hope we do not see it in our grafted offspring. We may not see any adverse effect of the Tight Bark then until the plant goes stagnant or becomes slowed down in its growth rate due to unforeseen or induced stresses. Then again if we were dealing with quick decline form of Verticillium, one stress is all that fungus needs to kill a Maple. I've had some two and three year old plants in the past come in from Oregon via mail order that endured 110 degree weather in full sun without any real major problems other than some expected wind scorch to the leaves and then a week to 10 days later back in the mid to high 90's wilt, shrivel up and be dead in one day. It makes little sense at times to us that while the tree was experiencing and seemingly enduring a heat stress that it (they) died soon after we had a cooling effect. Lost a fifteen gallon Tsuma gaki this year after it endured the hottest part of the year unscathed and then wham with temperatures back in the 80's for one day decided to die on us. The difference is that the much older Maple had endured a few stresses in recent years. It was after the first major stress a few years ago that any signs of Tight Bark was seen on this Maple but after another heat related stress the following year Tight Bark was seen allover this plant. May not have made a difference at all to the older Maple if I had it been in the ground or not. Has been rather common with Tsuma gaki in very warm areas for many years now, at least 30 years. Used to be this Maple dropped over dead at the drop of a hat many years ago for us here - one reason why we never grew it for resale. The two, same aged, companion Tsuma gaki to the one we lost are still alive and hanging in there but both Maples as a result are in the ground now as well. Jim
I've been looking all over for the thread where Mr. Shep explains turning a green palmatum red through successive grafting. Please help? Also, how many of you have experience/success grafting on red rootstock? I've had one grafter tell me his success rate went way down, but then he only tried it one year. I was going to suppliment my rootstock order for next year with some red, but that gave me pause. Any input would be appreciated.
