We got into a discussion on another thread about which species of Acers can be hybridized with each other. This started out specifically referring to Japanese Maple species, but I would expect there are a number of American species that could possibly be compatible with Japanese species when it comes to hybridization. So what is the complete list of inter-breeding capability? Anyone have the answer or a resource we could go to? Thanks!! i.e. : ACER SPECIES HYBRIDIZATION COMPATABILITY A. palmatum x A. shirasawanum = TRUE A. shirasawanum x A. japonicum = ?? A. palmatum x A. saccharum = FALSE A. palmatum x A. circinatum = TRUE A. japonicum x A. circinatum = ?? etc. etc. etc.....
That doesn't really tell me anything. Which species are closely related? I'm looking for specifics. Thanks!
Sorry, was assuming you'd be familiar with the classification system included in e.g. van Gelderen's maple books. The details are here: http://web.archive.org/web/20070812014108/http://www.inh.co.jp/~hayasida/Ebunrui1.html though a little awkward to follow (you need to visit each of the pages to see which species are in each group, the world overview doesn't list the species).
Michael, Thanks for this info; it was quite helpful. Off the top of your head, do you know of any notable exceptions to the general rule that only maples in a species sub-section are 'crossable'?
None that I know of that have been verified. There was a plant posted on this forum a few months ago said to be A. griseum × A. pseudoplatanus, but it had not been genetically verified yet.
Michael, What are your sources?, Cor van Gelderen (the 'selector') has stated (to me) that genetic tests have indeed confirmed the claimed hybridization. Gomero
OK, so if I'm getting this right, trees in the Plamata section, in the Palmata series could cross-pollinate. If I take the various lists and combine them all for that section and series, it would look something like this: Red = Japanese Blue = North American Green = Chinese PALMATA Section, Palmata Series, Species and Sub-species are: A.palmatum, A.matsumurae, A.japonicum, A.sieboldianum, A.shirasawanum, A.tenuifolium, A.circinatum, A.pseudosieboldianum, A.linganense, A.ceriferum, A.duplicato-serratum, A.pubipalmatum, A.pauciflorum A.changhuaense, A.robustum, A.anhweiense So in theory these should all be able to cross with each other. Whereas this grouping: A.sunyiense, A.sichourense, A.yaoshanicum, A.kweilinense, from the Sinensia Series could not cross-breed with species in the Palmata Series, even though they're in the Palmata Section. Right?? Wrong? Comments? Thanks!
Sorry, missed that! But equally, it is such an improbable combination, I'd really prefer to see it verified by an independent third party. That seems reasonable, unless any have evolved additional barriers to hybridisation to prevent potentially deleterious gene flow. This can sometimes occur; not maples of course, but as an example, northern populations of Pinus muricata cannot hybridise with southern populations of the same species. Don't know. I'd be surprised if they have even been tested, given their rarity.
Dr. Susan Wiegrefe, in addition to organizing the Tokyo Symposium ;o)), is a well known researcher in Maple Interspecific Hybridization. She has an article on the subject in the Proceedings of the 2002 International Maple Symposium. Concerning the Section Palmata, she found that hybrids of palmatum and japonicum were not viable whereas both of them separately crossed easily with pseudosieboldianum. Gomero
Based on the information presented so far, and excluding the uncommon/rare varieties from consideration, and already knowing the amoeum, matsumurae, palmatum, dissectum, linearlobum, sub-species interbreed, we come up with a list something like this: Red = Japanese Blue = North American Green = Chinese ACER SPECIES HYBRIDIZATION COMPATABILITY A. palmatum x A. shirasawanum = TRUE A. palmatum x A. japonicum = FALSE A. palmatum x A. circinatum = TRUE A. palmatum x A. pseudosieboldianum = TRUE A. japonicum x A. circinatum = TRUE A. japonicum x A. shirasawanum = TRUE A. japonicum x A. pseudosieboldianum = TRUE A. circinatum x A. shirasawanum = TRUE A. circinatum x A.pseudosieboldianum = TRUE A.pseudosieboldianum x A. shirasawanum= TRUE
If Dr. Wiegrefe has investigated it and found that to be the case, I don't see why not. Even very closely related taxa can evolve barriers to hybridisation, if the two taxa occur together and their hybrids are less fit than the parents - hybrids will not survive, and plants which avoid producing hybrids will have a selective advantage.
shirasawanum used to be thought of as a japonicum until it was re-classified if palmatum and shirasawanum will hybridise I am genuinely surprised if palmatum and japonicum will not .....
Re: O.T. Japonicum & Shirasawanum Shirasawanum was considered to be a subspecies of Japonicum and to some people still feel it is a subspecies of Japonicum. I suggest some people read the Delendick dissertation sometime and stand back from it and ask what procedural error of omission was made in the study. Essentially, a certain plant was wanted to be proved that it existed in cultivation prior to the Shirasawa's Maple officially being discovered. Today, we have Maples that have come into various countries as being a Japonicum that others now want to call Shirasawanum and for Ogurayama call it a Sieboldianum. Much of this is utter nonsense in my opinion but others are trying to get a better handle on what they had come in years ago and are expecting chemical tests to better prove that they are correct in changing the species grouping for a few cultivars such as Junihitoye (not to be confused with the palmatum Junihitoe). The dilemma for me is not so much thinking that the 20th century Japanese botanist views were wrong but to change the spelling of the names, even adding in hyphens, to correspond to others thinking that never owned or had access to the old books, manuscripts and plant catalogs that all were written, not all of them were published, in Japan wreaks of a hidden agenda conspiracy by Europe and others to claim ownership of Maples that were never theirs. To enlist China into the fray, whom had to resort to learning much of what they know about the Chinese Maples from the Japanese and merge the desires of the Europeans to coincide with Chinese recent versions and then include a sect from Japan that never really knew of the old teachings from Japan, spells trouble for those of us that learned these plants from people that actually had them, not simply said they did and spent years of studying them. There has always been some expressed jealousy in England garnered around one person that had access to anything in the US and with that in mind anything he wanted from Japan as well. To illogically blame or resent others for opening the door to have plants come into various areas such as Europe and Australia and even China and now claim their steadfast views on these plants are the only ones that are correct, simply slaps everyone in the face that spent their years of study with these plants just to have a few upstart intellectuals that really never had many of these plants around to know them well, tell the rest of us we have it all wrong and have since put all of us (alive and still capable of grazing) out to pasture. The one solace that some us do have is that we can help identify the cultivar when we see it and the "big sticks in the sky" (ready to pounce on any contrary opinion, even when it was the mainstream views held by the pioneers in Maples for many years in these plants) have not shown they can do that yet. We've seen enough proof in this forum in that the people wanting to force the rest of us to comply haven't a clue as to what some of the Maples are in the two photo galleries in this forum. The photos that members have shared is a treasure trove of cultivars that are and have been around in the nursery trade and from collections and we see no comments from the intellectual world as to what those Maples are based on their actually knowing them. If the old true form Tsuma beni is shown in this forum then tell people but it cannot be me to do it, thanks in part to how and what I am perceived as being as a person in this and other plant forums. Yet, I was present in the nursery when the old plant was purchased by the source that the member in this forum stated their plant came from. The intellectuals cannot do that either as they were not there and they have probably not ever seen the old plant from Japan which was the Maple that the Wada and Kobayashi selected forms came about from. I believe you people have access to a couple of photos of them but there will be no more photos of my plants in this forum in the future as all I did was waste my time hoping to encourage others that forms of these plants can be more important to know than the new names that others want to give them. If we look at the Geisha of mjh1676, I will be proved right that, that Maple does indeed produce a Fu but I may have to show him where it is and when he will see it. The crazy thing herein is that the nurseryman that many of you are so enamored with will already know that I have a pretty good idea what is going on with these plants based on who he knows of that taught me Maples. Let him tell it and when he gets it wrong or has someone else be his sounding board I will tell him in person but not in a forum format (a little professional courtesy can go a long way and besides, we know of each other!). A query of sorts: where does the Hohman Japonicum f. filicifolium fit in, to coincide, with the new age concept that both forma aconitifolium and filicifolium would now be considered a Shirasawanum? Mr. Hohman had that Maple in his collection for over 30 years before Shirasawas Maple had been discovered in Japan also.. Jim
It may certainly be counter-intuitive, but is far from impossible – Acer shirasawanum and A. japonicum are ecologically separated in Japan (A. s. has a warmer, more southerly distribution). I don't know the full details, but this could easily lead to a situation where A. palmatum occurs together with A. j. and has as a result evolved barriers to hybridisation; but not together with A. s., and therefore has not had an opportunity to evolve barriers to hybridisation.
Re: O.T. An applied viewpoint Another way to look at this is to think in terms of which species can be used as a rootstock for another species such as using a Shirasawanum scion onto a Palmatum, Japonicum, Sieboldianum, Semenovii, Buergerianum, Circinatum, etc.. rootstock. Generally if the scions are compatible to another species rootstock then by postulating there can be gametic union of the two species as well, depending on which species is the pollen parent and which one is the seed parent. The trouble here is that some species are compatible when one is grafted onto another such as grafting Palmatum onto Semenovii but the reverse process may not work too well such as grafting Semenovii onto a Palmatum rootstock as an example. What does the above tell us? In this case Semenovii is more likely to be receptive to Palmatum pollen than Palmatum will be to Semenovii pollen. So, in the instance of Vine Maple used as a cross with Sycamore Maple I'd want to know which one was the seed bearing parent and I'd want to know if the reverse process was ever tried to introduce variegation from Sycamore Maple into Vine Maple? Aside from application of the means of using the merging of protoplasts to breed Maples in a petri dish and then grow the unified cells on using tissue culture techniques, I am curious to know from the genetic test which species was confirmed to be the seed parent, if there indeed was one? It used to be incumbent to know which was the seed parent in proposing a hybrid just like it used to be imperative to know which Maple the limb sport came from. Today, so few people know the answer as to how a Baby Lace (only used as an example here, don’t get nervous) came about and which red dissectum it was found on as a branch sport. Some crossbreds have indeed occurred from asexual means as well as in other plants and can also be bred in Maples by way of using a parent rootstock more than once to introduce its recessive genome into a dominant scion genome. In the case of two species, the scion is dominant to the recessive species rootstock. Think of it as to how two-brown eyed parents can produce a blue-eyed offspring and you will know the basis of how a rootstock can be used as a tool in Plant Breeding (has been used in breeding Citrus for many years). Providing of course that someone can state with certainty that palmatum type Maples and their cousins are capable of crosspollination among themselves in the first place. Other means have been used to fool people into believing that a true hybrid had come about and one way to trigger a mutation in a plant is to double the chromosome number and for that an alkaloid Colchicine (from the root of the Autumn Crocus or Meadow Saffron) was used to do just that in other plants. Immerse and macerate the seeds in solution and then germinate the seeds on and see how much larger and different the leaves became from the seed parent plant. The real "Holy Grail" herein can be found in the vigorous growth these treated seedling plants could yield as the new growth could be wildly different than the seed bearing Mother plant was from which the seed came from. Graft only the vigorous growth from the seedlings and in a few years a series of newly named plants could be given to a whole spectrum of Maples. The problem will be and has been in the past is that few to none of the proposed hybrid improved plants were proved to be stable from seed, a majority of offspring that continually looked the same as the parent plant that produced them. From what katsura has written about his Maples and the lack of crosspollination he is seeing in the seedlings is a rather common event found from stable plants that are accustomed to being selfed - the female egg either does not need pollen to produce seed or that the same plants anthers provide enough pollen to fertilize the female egg. Unstable plants that were treated with Colchicine could give us a wide range of variance in the seedlings was the original premise. The dilemma was keeping the seedlings alive long enough to take wood from those seedlings so young in their development and graft them as scions onto various rootstocks hoping to settle the wild and vigorous growing plants down so that the offspring from them looked alike or closely resembling the other grafted offspring. In this case it did not matter if the seedlings looked like the Mother plant, the results meant more to some people if the seedling progeny did not look like the Mother. The former above did not always hold true of which F1's (filial one generation) could differ from each other and when the F1's were themselves grafted back onto a green seedling they themselves could change back and show the physical attributes of the non treated parent plants they originally came from. From a breeders or from a plant manipulators point of view that is not what they wanted to see at all (although seeing the plants return to wild type was not all bad as the frequency rate that some of these plants could send out limb sports later on went way up). To some people that was the whole benefit of trying new ways to generate abnormal growth and it worked pretty well for some Maples such as Kasagiyama and its known forms (purple, red, white and pink) and for Beni shigitatsu sawa and its counterpart white form Shiro shigitatsu sawa. Even limb sports have been grafted and called a hybrid when in fact they are not a bona fide hybrid at all. When a Bloodgood can produce a broom, then we have a mutant form of Bloodgood and we may even name it but it is not a genetic hybrid of Bloodgood. The tale of the tape lies in the seedlings raised from the broom sport. How many of the discarded seedlings were closer to being a Bloodgood than they were closer to being the broom (an exception are the witches brooms with the stubbed middle lobe in that these plants seldom if ever produce seed, let alone viable seed.)? In most cases in which experiments were conducted this far along from brooms, more than 95% of the offspring resembled the Bloodgood. Most of the time we only get at best the standard deviation used in laws of probability of +5% or -5% at best and even five plants out of 100 is an Earth shattering number of broom seedling progeny coming from any broom plant. Some plant breeders felt getting five broom plants out of 1000 seedling progeny would be considered fantastic results, even five plants out of 10,000 would be pretty darn good numbers. Pygmy Pines can and have produced cones. Not all pygmy forms will produce a cone but some have, whereas witches broom Pines and palmatum type Maples are considered to be female by some people but I've often wondered are they male-sterile instead, sterile males such as we have in some other plants? I told two members in this forum a while back of how red coloration was introduced into Seiryu by using the same red parent rootstock over and over to do it for us. By the time the F6's came about there was enough red coloration introduced into enough of the seedlings that one plant was selected out and was called a Red Seiryu prototype plant in that nursery. It took five more generations of plant selection to get an all red plant that remained red when grafted as scions onto green seedling rootstock. This was all done by asexual propagation. The same procedure can be used to introduce red coloration into Japonicum and Shirasawanum. I never doubted that someone could have figured out a way to get their 'Red Dawn', it is the procedural methods they used in order to get it will better determine if it is indeed a hybrid or not. If it came about from asexual means it is not a true hybrid unless it has shown it has the ability to breed true from seed into the seedlings. Even seed from the Red Seiryu finished plant yielded a high percentage of all green offspring. If it were a hybrid then 51-95% of the seedlings raised from it should have been red and not just show a red overtone for a while either. Not even 10% of the seedlings were all red from the Red Seiryu seedling trails. The only way to propagate this Maple from then on was to perpetually graft it or root cuttings from the all red trees that remained all red - some of the rooted cuttings didn't stay red either as some of them returned to being green again shortly after they produced leaves or within a few years but the grafted plants on red seedling rootstock did stay all red. Jim
I like the notion of trying to determine which species are compatible with each other for breeding potential hybrids but so many people have failed in their attempts in the past. The prevailing problem has been in many cases that the proposed hybrid crossbreds did not live long enough for people. It is not a matter that we cannot attempt to breed Maples but the bugaboo has been keeping the hybrids alive for any length of time. What good is it to say that this species can cross with another species and then none of the seedlings live for a year or up to five years for us? We still have not figured exactly out why such a small number of seedlings live right under the canopy of the parent plant in the ground either. Yet, seedlings from the same tree a few feet away from the tree seem to do a whole lot better or why seedlings from another type Maple do better grown under the canopy of that same tree. Even when people said they bred a certain Maple, they usually fail when they have to defend how they got it. It is not so simple to say that our hybrid cross is from Acer circinatum x Acer shirasawanum. The other constant for us is that crossbreds die out in the wild soon after germination. I wish it was different and I applaud people for trying but the "old guard" in Maples “kinda” gave up trying to breed Maples using sexual reproduction as their means they were using proved futile much of the time. If we can ever get past and able to move beyond how to keep the bona fide crossbreds alive long enough to do something with them then, until then, we really do not have a whole lot going for us. It was due to several failed attempts at trying to breed Maples that a technique used in Citrus and Camellia breeding was attempted in Maples and other plants later such as Dogwoods and even Magnolias. We can create a hybrid rootstock using asexual means to get there but in select trials the so-called hybrid rootstock was not pure enough to call it a hybrid but we can still use this mulatto to help us for what we are wanting in our cultivars. One of the reasons why seedling and cutting Kagero was used as a rootstock, to introduce variegation into some non variegated cultivars and to enhance other variegated cultivars, was its ability to do it by the third generation. How nice it is to take seed from our variegated Maple and see a majority of the seedlings be variegated, even when the scion portion of the plant is grafted onto a non variegated green rootstock. Does not happen too often as people tend to go bonkers over the one plant that is what they had hoped for, while not saying a word about all of the non variegated seedlings that may have to be or were discarded. We should not try to wantonly discard the non variegated seedlings. We saved them and used them as a rootstock for variegated cultivars. Not only did we have a high degree of variegation in the cultivar we want to use as scions but we also have a small degree of variegation already introduced into the genotype of the seedling, even when the seedling or seedlings from it may not show any variegation at all in its or their phenotype. We have the ability to breed a whole spectrum of variegated cultivars but it will take years to see the results of our work. May take 10-20 years to get what we wanted but if we put in the time and effort we should be rewarded later on. What a few people wanted was a standardized variegated rootstock to use on other cultivars such as Bloodgood, Burgundy Lace, Crimson Queen, Viridis and Ever Red but the real hope was to use these rootstocks to introduce variegation into the linearilobums, ribbon leafs, Pine barks, Cork barks, even the Snake Bark palmatums. The problem now is that most of the Snake bark, Cork bark and ribbon leaf palmatums have died out on us in cultivation but that does not mean there aren't some of those plants still around although there aren't many to choose from now. Not like there were in the 60's and 70's. People had the Maples and lost them over time due to disease factors such as Tight Bark and rather soon after grafting those plants due to soil introduced quick decline form Verticillium dahliae and further complicated along with Verticillium alboatrum already in the plants system and never really recovered from there. Now we can see a photo of one ribbon leaf Acer palmatum in the Ganshukutei web site when there used to be ten to twelve known cultivars 30 years ago - not a good, sustaining percentage of that distinct form of palmatum is it? We had them and we lost them and now we have little recourse to help bring them back! Back to topic now: interspecific breeding has been more proficient than intraspecific breeding has been. We are more likely to be able to cross known species forms easier than we can Maples of the same species such as palmatum to palmatum. Oddly enough we should have better results using amoenum with palmatum than we may get from palmatum x palmatum. The hard part to figure out is which pollen and which seed parent to use as one cross of amoenum x palmatum may have some results but palmatum x amoenum may be futile for us. For a long time the only natural occurring hybrid in palmatum type Maples was felt to be 'Shojo nomura' in that in one plant we could see physical attributes of both the Shojo red group and the Nomura red group of Maples. Many of the proposed intraspecific hybrids have come from limb sports instead and we have had people tout their newly named plants as having come from seedlings to the mass media and to close friends in the nursery trade tell them those plants all came from branch sports. I believe they come from branch sports until they can say with certainty how their so-called hybrid can be proved to have come from seedling selection. When I ask them about what technique they used to ensure crosspollination they usually want to go somewhere else and hide as the answer is not so simple to tell people. I know, I've been there and done the same thing, when I've asked myself okay, “fella“, how do you prove it is a hybrid when the test of proof is in the seedlings from that proposed hybrid plant and when the numbers of progeny do not add up, how can I call it a hybrid? I can't, in actuality or on paper. Now you know that 'Red Seiryu' was a created plant, did not come about naturally and there is a photo of that Maple in this forum - I was real surprised and somewhat overwhelmed to see it, although it had changed a little after being grafted onto green seedling rootstock for who knows how long since it was selectively released. Jim
