Author Topic: Origin of Yuzu, ichang lemon, sudachi and where does its resistance to cold come  (Read 1033 times)

Lauta_hibrid

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It is somewhat confusing where they come from since they are ancient species, but there is some research work, using genetic markers, that is allowing us to understand their ancestry and perhaps clarify where their resistance to cold comes from.

I have to search more, because I no longer remember what name the article had where it showed that Yuzu came from crossing a wild Chinese mandarin x ichang papeda.  It would be good to get someone from the forum who is from that area of China and goes out to look for these ancient seeds that would be a good contribution for resistant genetics.  On the other hand, yuzu has generated other hybrids such as sudachi and Ichang lemon.  but I just found an article that ends up clarifying where the motherhood of ichang lemon comes from: the C. maxima.

https://pubs.acs.org/doi/10.1021/acs.jafc.0c07894




Lauta_hibrid

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https://www.nature.com/articles/s41467-021-24653-0#:~:text=Citrus%20ryukyuensis%20is%20a%20new,ryukyuensis%20sp.

Here I found him, he is presenting a new species of wild mandarin from Japan that separated from the Chinese population.  To understand the graphs I give them the classification: PU=pummelo (C. maxima), RK=C.  ryukyuensis, MS=mangshanyeju, MA=common mandarin, MM=generic C. reticulata without subspecies assignment (MS vs MA), UNK=unknown.




mikkel

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I think there is new research that says yuzu is a descendant of a species closely related to ichangensis, but not ichangensis itself.
@Ilya11

Ilya11

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It was shown here (corrected):

link1
link2
« Last Edit: February 09, 2024, 05:09:24 PM by Ilya11 »
Best regards,
                       Ilya

Lauta_hibrid

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It was shown here:
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0166969
https://www.hst-j.org/articles/xml/0R08/

I couldn't open it directly, but by searching the links on Google I found 2 works, but none of them mention anything about a species related to C. ichangensis that is not the same.  Could you take a screenshot of where it mentions it?  to see if you take it as a statement or just a speculation or hypothesis.  From what I see there are times that separate "populations" in nature can have genetic variability that distinguishes what is in the collections.  It's like what happens in one of the works I uploaded, which talks about wild populations such as wild Mangshyan mandarin (I think it separated from the common mandarin 2 million years ago) but it is still classified as the same species.


SoCal2warm

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I think there is new research that says yuzu is a descendant of a species closely related to ichangensis, but not ichangensis itself.
In my opinion, it's unknown whether yuzu is descended directly from ichangensis.
There are several indicators that strongly suggest yuzu descended from ichangensis, or a close relative or ancestor of ichangensis.

As one of the rare people who have had the opportunity to smell and taste both fruits freshly picked from the tree, in my opinion the aroma strongly seems to indicate to me that yuzu probably descended from ichangensis (combined with some other mandarin orange type presumably).

Genetic marker analysis does not always give the most definitive results of ancestry, but it is generally agreed the two are very closely related.

Likewise, as far as I know, it's not known for sure whether Ichang lemon descends from yuzu or from ichangensis, precisely. But it must be one of those two. 

Lauta_hibrid

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I think there is new research that says yuzu is a descendant of a species closely related to ichangensis, but not ichangensis itself.
In my opinion, it's unknown whether yuzu is descended directly from ichangensis.
There are several indicators that strongly suggest yuzu descended from ichangensis, or a close relative or ancestor of ichangensis.

As one of the rare people who have had the opportunity to smell and taste both fruits freshly picked from the tree, in my opinion the aroma strongly seems to indicate to me that yuzu probably descended from ichangensis (combined with some other mandarin orange type presumably).

Genetic marker analysis does not always give the most definitive results of ancestry, but it is generally agreed the two are very closely related.

Likewise, as far as I know, it's not known for sure whether Ichang lemon descends from yuzu or from ichangensis, precisely. But it must be one of those two.

Thank you very much for clarifying that doubt, here in Argentina I think no one has citrus ichangensis, but this year I will be able to harvest my first fruits, luckily.  I use taste and smell a lot to investigate, we practically have a "mass spectrometer" in our senses, we can find molecules just by feeling them 😊.  My yuzus are very green since they are harvested in July here, but from what I can find, green is a smell (close to the peel) that reminds me more of the Common mandarin (in the US they call it Willow left).  but when it is ripe I will be able to analyze it in more detail, I don't know if you tried that variety to see if you found something similar or it is just an appreciation due to lack of tools to compare.  The publication was to present these research works that shed some light, obviously they are not final, but they all coincide in certain characteristics.  I find it more useful to take research work done by professionals and provide their conclusions before just speculating or inventing because "it seems to Lautaro" 😋.  Each investigation overlaps and does not contradict others, so I see it as quite solid.  In the longest one it talks about types/populations/subspecies of mandarins, and it seems that a wild population is the closest to Yuzu, the manshangyeju, meaning that the common one would not be its parent.  and the seed came from C. ichangensis.  It is logical because of the story told in the Riverside collection, where it mentions that it grows wild in China.  To my understanding, Ichangensis trees may have been planted near wild populations of these mandarins and only the pollen passed from one flower to the other.  This is because ichangensis is used for its aroma in China.  (this is just my idea).  What is it for us?  Well, it could be to repeat the experience and recreate the Yuzu, perhaps using another type of mandarin, as I make many hybrids, I could see what happens,😋.  and the other thing is to try to understand that maybe the Yuzu's resistance does not come from Ichangensis... maybe it comes from its Mandarin Parent (from the wild cultivar).  and for our hybrids it may be better to use tangerines.  Then I see if I can make a graph with the visual image and in proportion to what this research says and comparing sizes with the wild mandarin.

mikkel

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I agree that genetic tests are only ever meaningful in relation to the material tested and that results can change if the test is extended. However, in relation to the material that was analysed, genetic studies are absolutely conclusive and definitive. What you can ask is whether it might be better to investigate other species, whether the question could be improved.

With regard to yuzu and ichangensis, however, it is the case that ichangensis cannot genetically be the parental species of yuzu. Whether the true parent species is a close relative or just an as yet unknown type of ichangensis, who knows, that is speculation.

However, sensory impressions are not proof that genetic tests are wrong, they are at best indications.

@SoCal2warm In Europe, ichangensis and yuzu are quite common and not so rare. I wouldn't go so far as to doubt genetic studies just because I've tasted both fruits once.  You can make an assumption and others can make contrary assumptions, but none of that is proof!
« Last Edit: February 12, 2024, 02:31:05 AM by mikkel »

Till

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I agree with Mikkel. The idea that Yuzu descents from C. ichangensis was first of all a mere guess of Walter Swingle. It was a plausible guess. But that his idea has been repeated many thousand times in the last 100 years does not make it more true than genetic studies. Ichang Lemon is according to genetic studies a descendant of Yuzu.
There is a rule in science that we must not cast doubt on any believe without a good reason. Taste is not a very good reason I would say because C. ichangensis is a quite variable species. Different varieties have different fruits. And taste of hybrids is not necessarily conform to the taste of parental species.
Tanaka, by the way, was never convinced by Swingle even before genetic studies could be made.
Yuzu is an extremly old cultivar. It is well possible that its ancestor has died out.

Lauta_hibrid

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Yes yes, I totally agree with @mikkel, the sensory part is just a field tool, just as in geology mineral samples are sometimes tested to deduce some things.  I remember that from college.  It also helps to ingest things, like what happened to me with the fukushu kumquat, which I see old descriptions that talk about it being its own species and when I scrape the leaf it smells perfectly like tangerine (from which it was discovered that it could not be a hybrid ?).  or as in Orangequat (I still put into play that I do not have a registered strain but rather a collector's plant) according to my plant its fruits are both round and oval, how can they be oval if it is assumed and repeated that it is a hybrid of Meiwa x satsuma?  It would have to be round or flattened, and its seeds are zygotic... those two characters are only in Nagami.  These are field and morphological tests that make me disagree.

But there is something that does puzzle me, which is why it is being inferred that there may be an unknown species or subspecies of Ichangensis?  because in everything I read that was published, none of the researchers propose that, that's what I don't understand.  work after work accept and confirm that ichangensis is the mother of the seed, what is the source to infer that it is not?  If it is an assumption of the members of the forum, because the analyzes do not give 100% the same, that is only with respect to the samples, just as the Common mandarin is not 100% the wild Mangshan mandarin, that is because it is a separate population, but it doesn't say that both are not mandarin oranges, in fact they are both C. reticulata.  Is there any research work that you provide me that infers another species or variety of Ichangensis?

SoCal2warm

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My yuzus are very green since they are harvested in July here, but from what I can find, green is a smell (close to the peel) that reminds me more of the Common mandarin (in the US they call it Willow left).  but when it is ripe I will be able to analyze it in more detail, I don't know if you tried that variety to see if you found something similar or it is just an appreciation due to lack of tools to compare.
I have seen once and bought yuzu fruits at a luxury supermarket near where I live. Very surprised to see that. But they most have been picked unripe, because the fruits were much more on the green color side than yellow. I know it certainly was yuzu, but the fruits were very different from the ripe yuzu fruits I have picked off the tree. The skin of the green fruits was much harder and not edible. Whereas the skin of the very ripe yellow-orange fruits was soft tender, similar to citron (Citrus medica), and the skin is somewhat edible.

I think the best time to pick yuzu is when the fruits are yellow and beginning to become orange, but have not become too orange yellow in color. Before then they have not developed a strong aroma and are very unripe and dry, but after that they start losing sourness and becoming just a little bit insipid, maybe also lose just a tiny bit of aroma.

I realize in different climates, more tropical climates, citrus fruits often remain green and do not turn orange. I do not know how that affects yuzu fruit. But I am saying in other climates, if yuzu is green it is unripe and will not be so good. It will not give you a good idea of what yuzu fruit is supposed to be like.

The peel of yuzu is very important and is where most of the flavor is. It is nothing like an edible kumquat, but if you process the yuzu it has many culinary uses. Think of it like a lemon. 

In the longest one it talks about types/populations/subspecies of mandarins, and it seems that a wild population is the closest to Yuzu, the manshangyeju, meaning that the common one would not be its parent.  and the seed came from C. ichangensis.  It is logical because of the story told in the Riverside collection, where it mentions that it grows wild in China.  To my understanding, Ichangensis trees may have been planted near wild populations of these mandarins and only the pollen passed from one flower to the other.  This is because ichangensis is used for its aroma in China.  (this is just my idea).  What is it for us?  Well, it could be to repeat the experience and recreate the Yuzu, perhaps using another type of mandarin, as I make many hybrids, I could see what happens,😋.  and the other thing is to try to understand that maybe the Yuzu's resistance does not come from Ichangensis... maybe it comes from its Mandarin Parent (from the wild cultivar).  and for our hybrids it may be better to use tangerines. 
I could not speculate on precisely what the other ancestral parent of yuzu is. But it seems that ichangensis must have crossed with some sort of mandarin orange or sour orange type species. Because the aroma of yuzu has much in common with ichangensis, but whereas ichangensis leans more towards a "pure lemon" citron and lime aroma, yuzu is shifted much more in an "orange" or mandarin orange direction, or perhaps almost fragrant sour orange. Based on the tenderness of the peel, I would have to guess the ancestor is much closer to mandarin orange than orange. The peel of yuzu reminds me most of Satsuma mandarins, but the peel of yuzu is even more tender and less bitter than Satsuma. The genetic studies of yuzu have shown no signs of pomelo (Citrus maxima) ancestry, but that does not absolutely mean it could not be there.
The hypothesis that the ancestor might have been some sort of more wild sour mandarin species is not an unreasonable one. You can look up Citrus indica. It might have been something like that. But this is complete speculation, I really do not know.

 
Then I see if I can make a graph with the visual image and in proportion to what this research says and comparing sizes with the wild mandarin.
The genetic marker studies I have seen on yuzu show very strong dominance of ichangensis in its genes. That means yuzu may not be a direct single generation hybrid, but rather propagated on its own, sexually, and over time the ichangensis genes dominated. I have not seen any genetic studies giving any indication more specifically what type the other ancestor of yuzu might be.

You can consider that, although mandarin oranges are not very cold tolerant, they are usually much more cold tolerant than ordinary sweet orange.

I am thinking it is possible yuzu got some moderate cold tolerant genes from its mandarin orange type ancestor, but almost certainly yuzu must have gotten most of its cold tolerant genes from ichangensis.

Every source I have found says ichangensis is supposed to be much more cold tolerant than yuzu, but my personal experience seems to contradict that.
I have tried growing two ichangensis plants and they were unable to survive here. They went through the first winter but were unable to recover well, which meant they were unable to recover after the second winter. But the yuzu plants I have grown seem to have been more cold tolerant and survived better. Although some of the yuzu plants declined after 2 or 3 years and finally died.
I know with certainty what I grew was ichangensis. I do not know why my experience is different from others. Perhaps it has to do with climate, or perhaps I got a bad ichangensis variety.
I have some Yuzu and a Changsha mandarin plant that appear to be surviving well.

I even tried growing two seedlings that came from an Ichangquat (kumquat x ichangensis) cross, and they finally did not end up surviving outside, seemed less able to survive than Yuzu seedlings I have grown. I am thinking it might not have to do with just actual cold tolerance, it might have to do with vigor and ability to grow after winter. The climate where I am does not get much heat until late June into the year.

Perhaps ichangensis is better in climates that get more heat earlier after winter. I do not know.
« Last Edit: February 12, 2024, 03:26:52 PM by SoCal2warm »

SoCal2warm

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@SoCal2warm In Europe, ichangensis and yuzu are quite common and not so rare. I wouldn't go so far as to doubt genetic studies just because I've tasted both fruits once.  You can make an assumption and others can make contrary assumptions, but none of that is proof!
I was not doubting the genetic studies. My taste of the fruits confirms what the genetic studies say.
The two agree.

With regard to yuzu and ichangensis, however, it is the case that ichangensis cannot genetically be the parental species of yuzu. Whether the true parent species is a close relative or just an as yet unknown type of ichangensis, who knows, that is speculation.
I was not claiming it was the direct actual parent. Just that it is the ancestral parent.
Sort of like Adam and Eve are our parents.

If it is not a direct ancestor, then the parent is probably very closely related. The same species, or almost the same species. We know there are a couple different phenotypes of ichangensis. This species has a lot of genetic diversity and variability, and probably had even more diversity in ancient times.

I am not saying you are incorrect, but I also do not believe it is incorrect to say that ichangensis is the parent of yuzu, if we are talking about it in a general sense, one that might not be entirely precisely accurate. Sometimes it is better to just simplify things to express a truth, even if that simplification does not capture all the details and might technically be inaccurate.

I suspect after first coming into existence, yuzu must have been propagating by itself, occasionally sexually, in its own genetic pool. That it is not just a simple direct hybrid.

In my opinion, the fact that most yuzu seeds are nucellar (genetic clones of the parent) is an indicator that yuzu probably does not represent a true species (though does not prove it). Typically hybridization between two disparate citrus species results in nucellar seeds, whereas the original species have zygotic seeds. Although it is possible over time for hybrids to start becoming their own distinct separate species.

In conclusion, we might not know with absolute certainty precisely and exactly where yuzu came from, but we have a very good indication and know generally (in a more vague sense).
« Last Edit: February 12, 2024, 04:01:40 PM by SoCal2warm »

mikkel

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"I could not speculate... But it seems that ...
I see a certain contradiction in the line of argumentation
 8)

I`am out...

Lauta_hibrid

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Perhaps the commotion was created because this article was overlooked:

https://www.nature.com/articles/s41467-021-24653-0#:~:text=Citrus%20ryukyuensis%20is%20a%20new,ryukyuensis%20sp

This talks about the description of the "Origin of mandarins", postulates that in Japan there is a different, monoembryonic population and designates it another species name.  In the analyzed population of wild, semi-domestic and domestic mandarins from China he finds a new "wild" population that contributed genes to many current varieties from China and Japan.  This one is called MS=mangshanyeju .  When he extends the graph he adds the genetic composition of many varieties and hybrids and it is elucidated that "MS = mangshanyeju" is the father of Yuzu, he means that this variety is the one that created yuzu.  the other parent indicates it as C. ichangensis.  (like all the other research works that we put in this Post).  He states that through multiple investigations it is confirmed that Yuzu is a hybrid of C. ichangensis x C. reticulata (from the population = mangshanyeju).  Now I have not seen any research looking for the correct population, genetically closest, of C. ichangensis, let us keep in mind that it is a pure species with a wide distribution, you can see it in other populations of oysters species such as C. medica that there are countless forms , sizes and various characteristics.  the same should happen with ichangensis.  In other words, the one in each person's yard "does not create the yuzu" but rather its seed mother is a member of the "C. ichangensis species" and nothing has refuted that nor does any research contradict it.

Here is the graph of how the Chinese mandarin populations were separated.:




here where they mention Yuzu and confirm ichangensis in their genetics (the other color represents Manshangyeju):




and finally a graphic of mine showing the varieties with the photo of Manshangyeju so you can see what it is like.  There may be a problem with the scales, I will make a better image later, but it serves as a reference.  (Notice that the leaf of this mandarin is narrow and long... similar to Willow left mandarin. (in the research it shows quite pure genetics with very little contribution of genes from C.maxima):




caladri

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My yuzus are very green since they are harvested in July here, but from what I can find, green is a smell (close to the peel) that reminds me more of the Common mandarin (in the US they call it Willow left).  but when it is ripe I will be able to analyze it in more detail, I don't know if you tried that variety to see if you found something similar or it is just an appreciation due to lack of tools to compare.
I have seen once and bought yuzu fruits at a luxury supermarket near where I live. Very surprised to see that. But they most have been picked unripe, because the fruits were much more on the green color side than yellow. I know it certainly was yuzu, but the fruits were very different from the ripe yuzu fruits I have picked off the tree. The skin of the green fruits was much harder and not edible. Whereas the skin of the very ripe yellow-orange fruits was soft tender, similar to citron (Citrus medica), and the skin is somewhat edible.

I think the best time to pick yuzu is when the fruits are yellow and beginning to become orange, but have not become too orange yellow in color. Before then they have not developed a strong aroma and are very unripe and dry, but after that they start losing sourness and becoming just a little bit insipid, maybe also lose just a tiny bit of aroma.

I realize in different climates, more tropical climates, citrus fruits often remain green and do not turn orange. I do not know how that affects yuzu fruit. But I am saying in other climates, if yuzu is green it is unripe and will not be so good. It will not give you a good idea of what yuzu fruit is supposed to be like.

The peel of yuzu is very important and is where most of the flavor is. It is nothing like an edible kumquat, but if you process the yuzu it has many culinary uses. Think of it like a lemon. 

Yuzu grown in California are very different to yuzu grown in various parts of Japan even before one gets into the reality of multiple varieties of yuzu in commercial production. Green yuzu have distinct uses in Japan. I am a little surprised at the claim that yuzu are terribly rare to find fruit of in western Washington. Buy a box from Pearson Ranch some time. Uwajimaya used to have them. Pretty sure the Yard Birds supermarket in Centralia/Chehalis used to have them (they used to buy in every kind of citrus they could, including mandarinquats).

If you find yourself in BC at the right time of year, I can point you to multiple sources of Japan-grown yuzu you can try.

SoCal2warm

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When he extends the graph he adds the genetic composition of many varieties and hybrids and it is elucidated that "MS = mangshanyeju" is the father of Yuzu, he means that this variety is the one that created yuzu.  the other parent indicates it as C. ichangensis.  (like all the other research works that we put in this Post).  He states that through multiple investigations it is confirmed that Yuzu is a hybrid of C. ichangensis x C. reticulata (from the population = mangshanyeju).
The pictures of mangshanyeju mandarin fruits (Citrus mangshanensis) do look extremely similar to Yuzu.

One thing I will point out is that most pictures of mangshanyeju show very elongated leaves, which is not how the leaves of Yuzu look.
But I have found one picture of mangshanyeju showing more regular stocky leaves, which look like yuzu.
(accession MS3 from Lun Wang et al. 2018 that came from Mangshan Mountain, shown in the French language Wikipedia page)

SoCal2warm

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What I notice is if you look on a map of China, Hong Kong to Mangshan mountain to Changsha to Yichang are all in a straight line going north.
(each separated by a distance of about 245 kilometers by air)

Mangshan is where Citrus mangshanensis comes from, Changsha - the Changsha mandarin, and Yichang is the area where ichangensis comes from.
So it's probably not a coincidence.

This does sort of suggest to me that more likely Yuzu came about caused by human civilization. Trees of one of the two species were probably moved out of their native range, which allowed cross-pollination to happen.
« Last Edit: February 12, 2024, 05:52:41 PM by SoCal2warm »

Lauta_hibrid

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   Well, the topic went on, I like that everyone contributes.  I hope to soon get some buds and so please have a c tree here.  ichangensis 😊.  maybe create some new crazy hybrids hehe.  but for now I'll settle for yuzu that I was able to pollinate several things (kumquat, satsumas, lemons, grapefruits, dekopon, ortanique and limequat).  but in the meantime I'll just investigate more.  Here I found a research paper on this species and a supposed distribution... perhaps it provides a little more of the history of how a wild mandarin crossed with ichangensis.  This is the publication and here is a clipping of a graph.

https://www.researchgate.net/publication/313230114_Molecular_phylogeography_and_population_evolution_analysis_of_Citrus_ichangensis_Rutaceae




Lauta_hibrid

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When he extends the graph he adds the genetic composition of many varieties and hybrids and it is elucidated that "MS = mangshanyeju" is the father of Yuzu, he means that this variety is the one that created yuzu.  the other parent indicates it as C. ichangensis.  (like all the other research works that we put in this Post).  He states that through multiple investigations it is confirmed that Yuzu is a hybrid of C. ichangensis x C. reticulata (from the population = mangshanyeju).
The pictures of mangshanyeju mandarin fruits (Citrus mangshanensis) do look extremely similar to Yuzu.

One thing I will point out is that most pictures of mangshanyeju show very elongated leaves, which is not how the leaves of Yuzu look.
But I have found one picture of mangshanyeju showing more regular stocky leaves, which look like yuzu.
(accession MS3 from Lun Wang et al. 2018 that came from Mangshan Mountain, shown in the French language Wikipedia page)

If you refer to this article, be careful, whoever did it mixed photos from the original article, in the investigation there is a complementary text that has photos of the collected samples, there are several wild mandarins and there is also the new species, which has nothing to do with it. see with the mandarin (it is evolutionarily distant) which is C. mangshanensis.  but the cover photo is a tangerine.  I leave you an evolutionary tree where I managed to collect all the natural (pure) citrus fruits that exist and were presented in research work.  It took me more than a year to do it, I hope it helps you (they are scaled so you can compare sizes) 😊💪

https://fr.m.wikipedia.org/wiki/Mangshanyegan




mikkel

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"Swingle considered it a unique variety related to papeda, and regarded yuzu as a chance seedling of C. ichangensis [11]. However, the allele-sharing test clearly refutes this proposal, with 31 out of 123 DNA markers not shared between yuzu and C. ichangensis. Because the cytotype of C. ichangensis was unique, but the lemon-type cytotype was found in 13 varieties "

"These observations hypothesized that C. ichangensis could an offspring of an unidentified papeda lemon, and yuzu might also be an offspring of this unidentified papeda."


in "Results" Paragraph 8
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0166969


Lauta_hibrid

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I read it back and it says the same thing, here I took screenshots of the parts of the analysis.  C. medica appeared in the graph in the same place as C. ichangensis, they are clearly different and were raised in large multidisciplinary and international works.  There in the text it says that possibly discarding some results could be the reason that C. ichangensis and C. medica will be placed together and that Yuzu is still closer to C. ichangensis and C. reticulata, confirming what has already been stated in others occasions.  Furthermore, if multiple research projects reach the same point and one proposes something different, science is consolidated by evidence and because its results are repeatable, not by exceptions.  I had already seen other research articles that, if they cared, raised c.  medica as homologous to C. ichangensis, which those who do comparative morphology clearly disagree on everything.  There was also a similar genetic phenomenon when research into the origin of citrus fruits was done.  The results showed that C. medica was related to Australian citrus trees, but only in the chloroplast genome. This was considered an error and it was clarified that it made a phylogenetic tree that was not very parsimonious, meaning that it posed more problems than solutions.




SoCal2warm

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However, the allele-sharing test clearly refutes this proposal, with 31 out of 123 DNA markers not shared between yuzu and C. ichangensis. Because the cytotype of C. ichangensis was unique, but the lemon-type cytotype was found in 13 varieties "

"These observations hypothesized that C. ichangensis could an offspring of an unidentified papeda lemon, and yuzu might also be an offspring of this unidentified papeda."
It's interesting, but I think you have to take the interpretation of these genetic marker analyses with a huge grain of salt and some skepticism.

C. ichangensis is a lot more closely related to citron (C. medica) than most any of the other varieties (despite the huge difference in cold tolerance, with citron having less cold tolerance than even most ordinary citrus fruits).

So we could postulate there are "citron-type" genes in C. ichangensis, convenient genetic markers that ichangensis shares with citron.
If ichangensis hybridized with something else (such as mangshanensis), then not all the ichangensis genes would have carried over. It could be possible all the citron-type genes did not get passed on. Especially if Yuzu went through a series of sexual propagations to get to its present gene profile.

When the Japanese researchers refer to "lemon type", I assume it is very likely what they actually mean is "citron type". (citron is the primary ancestor of lemon, where lemon gets most of its distinct character from)

So it might only appear that ichangensis had some other ancestry that yuzu does not. That is a possibility.

Another possibility (which I find to be much less likely) is that human civilization might have grown potted citron near the Yangtze River around Yichang, and then the citron plant contaminated the gene pool of the entire population of native papedas.
Citron used to be a common ornamental plant in Chinese civilization.
For that to have happened, something in the citron genes would have had to confer some advantage that the original papeda species did not have, which I think is not so likely.

mikkel

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I read it back and it says the same thing, here I took screenshots of the parts of the analysis.  C. medica appeared in the graph in the same place as C. ichangensis, they are clearly different and were raised in large multidisciplinary and international works.  There in the text it says that possibly discarding some results could be the reason that C. ichangensis and C. medica will be placed together and that Yuzu is still closer to C. ichangensis and C. reticulata, confirming what has already been stated in others occasions.  Furthermore, if multiple research projects reach the same point and one proposes something different, science is consolidated by evidence and because its results are repeatable, not by exceptions.  I had already seen other research articles that, if they cared, raised c.  medica as homologous to C. ichangensis, which those who do comparative morphology clearly disagree on everything.  There was also a similar genetic phenomenon when research into the origin of citrus fruits was done.  The results showed that C. medica was related to Australian citrus trees, but only in the chloroplast genome. This was considered an error and it was clarified that it made a phylogenetic tree that was not very parsimonious, meaning that it posed more problems than solutions.




if you compare different papers you will find that the species and types sometimes fall into different clusters. Depending on which genetic markers were analysed.  This is not surprising. The study only provides an answer to the specific question, everything else remains interpretation.
I think it is difficult to try to force a clear answer here, there are studies that have delivered results. They were not wrong, the overall picture emerges until the next study comes along, which can change or confirm everything.
If some people here reinterpret research results based on taste and personal impressions, turn lemon into citron, turn the results upside down to suit their own personal preferences (I'm not talking about you, Lauta!), then this is not helpful, it creates confusion and is pure speculation and certainly not scientific.
I don't think the question of yuzu ancestry is clear one way or the other, but the results show that there are several possible interpretations, depending on the genetic markers analysed.
The two links Ilya posted point in the direction of non-parenthood. This cannot simply be ignored or overruled by the majority. The categorisation of the results is an interpretation, we must be aware of that. And our interpretation is amateur interpretation


drymifolia

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And I think it's worth reiterating that recent papers have shown that some of the most popular methods of doing genetic testing using markers were deeply flawed and gave false positives for markers at a much higher rate than anyone realized. Also, that the statistical software used to produce those phylogenetic trees also had major flaws apart from the false positives. Basically, it seems likely that any study using genetic markers over the last 25 years is going to need to be redone using whole genomes because it was inaccurate.

So you will have to wait for whole genome analysis to get a real answer to the question.
« Last Edit: February 14, 2024, 03:00:41 AM by drymifolia »

SoCal2warm

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Furthermore, if multiple research projects reach the same point and one proposes something different, science is consolidated by evidence and because its results are repeatable, not by exceptions.
Unfortunately I think you are confusing "science" with what this actually is.
(You are making an error in reasoning known as equivocation fallacy)

You are treating this as if these are different experiments that each prove the same thing. In actuality, each of these studies are just examining certain markers. Probably many of those markers overlap between the different studies.
It is not really fair to say that because multiple studies have pointed to the same result that it means this is much greater evidence than if it were just one of these studies.

It might be more appropriate to view this in terms of mathematical statistics, but even to do that you would have to compare exact genetic markers between these studies, which would be difficult (for us).

If some people here reinterpret research results based on taste and personal impressions, turn lemon into citron, turn the results upside down to suit their own personal preferences (I'm not talking about you, Lauta!), then this is not helpful, it creates confusion and is pure speculation and certainly not scientific.
I accept your criticism, and you have a point, but I think the specific example you pointed to, turn lemon into citron, is a really bad example to point to, on your part.

True, I did a lot of other speculation in my post, but that specific thing (lemon into citron) is a very obvious thing, I think. I might not have precisely logically derived it from the specific data, but it is common sense.

Unfortunately I am afraid there may be a little bit of a language barrier between us, so communication about some of these precise things might be difficult.
« Last Edit: February 14, 2024, 05:19:47 AM by SoCal2warm »

 

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