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teddytn

Cold hardiness an acquired ability?

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Fallen Munk
10 hours ago, Jesse PNW said:

I've never heard of lizards changing organ functions over a couple generations, i would be interested in reading about that.  I have never heard any evidence of mutations occurring due to any type of external influence.  

As a former reptile breeder, it's not so much mutation as environmentally forced evolution of slight variations driven by survival of the fittest.  Take panther chameleons from Madagascar as an example.  Each locale can develop widely different color variations based on the locale foliage.  Outliers get eaten by predators because their camouflage does not hide them.  This happens over just a few generations.  

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Xenon

The environment (or people) can only select from existing variation in the population. The environment itself is not the cause of variation. Barring mutation, gene flow, or genetic engineering, you aren't going to significantly improve the hardiness of a palm beyond the existing natural variation in hardiness. 

Outside gene flow from hybridization is probably the most realistic avenue for increasing cold hardiness without splicing genes manually or shooting X-rays and hoping for the best. In theory, you could transfer genes for cold tolerance from a more tolerant species to a less tolerant species (ex: Butia odorata -> Syagrus romanzoffiana) via repeated backcrossing (introgression) to create something that is nearly "pure" Syagrus romanzoffiana with the introgressed gene(s) for greater cold tolerance. This is assuming you could identify the gene(s) responsible for cold tolerance, isolate and express it in a way that doesn't affect the phenotype (appearance) of your desired outcome i.e a pure looking Syagrus romanzoffiana. However, it's likely that cold tolerance is polygenic and tied (or synonymous) to other genes that affect phenotype (such as leaf thickness, wax production, etc). 

Palms cannot "acquire" cold tolerance, a more cold tolerant specimen represents already existing variation. Some palms like Syagrus romanzoffiana and Bismarckia nobilis have relatively high genetic variation to cold tolerance vs palms with very low variation (most lowland equatorial species). Also, it's incredibly difficult to "control" for genetic tolerance vs outside factors such as crown height, soil moisture, soil biology, etc. 

 

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Fallen Munk
20 minutes ago, Xenon said:

The environment (or people) can only select from existing variation in the population. The environment itself is not the cause of variation.

 

Agree.  If the variation has a better survival rate it will be the dominant strain.  At some point, nature creates a bottleneck.  Something all of us zone pushers need to keep in mind.  That one winter that is the bottleneck.

 

That being said, I would not entirely rule out an individual palms ability to adapt to an environment to survive.  Temperature, humidity, soil type, etc.  Non genetic of course.  Coping mechanism.

Edited by Fallen Munk
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UK_Palms

Clearly the environment is a factor in variation, otherwise we would only have a fraction of the number of species available today. Look at Chamaerops for instance, which would have just started out as the basic green type in southern Europe perhaps 20,000 years ago. At some point that spread to north Africa and in order to combat the colder nights at higher elevation in the Atlas mountain regions, it has mutated and become the 'Cerifera' or Argentea type. This is now unique to that region. Some nights go below 5F in that region, so that form of Chamaerops has clearly undergone changes to allow it to become more hardy to survive there, compared to the original green version from southern Europe which cannot.

Likewise on some of the Italian islands, smaller, compact forms of Chamaerops have been found with different looking fronds, which cannot be found anywhere else. On one island where there are lots of feral goats, the Chamaerops are way thornier than average too with thorns on the fronds even, in order to combat the goats eating them. And those feral goats weren't introduced until the 1700's at the earliest, so the changes must have come about relatively quickly. If environmental factors weren't a cause for variation, we would just have the basic green type of Chamaerops and no others. However there are about 6-7 different sub-populations of Chamaerops now. It clearly also wouldn't be present in the Atlas mountains, but underwent changes enabling it to colonise that region about 5,000 years ago. There has been some genetic testing done to show this. 

@Xenon So you're saying that you don't think Washingtonia seed produced from survivors of the Texas freeze will result in more cold-hardy specimens in the future, potentially? So you are refuting that theory, right? Given that you say that environmental factors cannot influence cold hardy genetics. The same goes for the Truth or Consequences Filifera, which by your reckoning should be no more hardier than bog standard Filifera, right? Or are they actually more hardy because they came from survivors of previous freezes and have been selected for their tougher traits, creating hardier seed stock, whether naturally or through human intervention. Continued backcrossing should in theory result in hardier seed stock.

In which case, the idea of zone pushing borderline species, selecting the survivors and toughest specimens and then forcing them to set seed over a number of generations, in less than ideal climates, clearly must produce hardier individuals further down the line, since the weaker won't survive. It may even result in mutations and different species altogether, which is how different species of the same genus have ultimately come about. I am not saying that is definitely the case, but it seems extremely plausible to me. Take Dactylifera for instance, if it did morph into Theophrasti, Reclinata and CIDP as it expanded outside of its natural range. It probably morphed into CIDP to handle the wet-cold Atlantic conditions, especially on the windward side of the Canary islands and in the mountainous interiors. Again, I am just speculating on that though.

It's also interesting that the higher elevation CIDP's on Tenerife have fatter trunks and are supposedly more leaf-hardy by up to 5F. So there is almost certainly some evidence of more cold-hardier variations of the same species, dependent on climatic factors. I wouldn't be surprised if the UK born and bred CIDP's eventually form fatter trunks and more leaf hardy traits over a number of generations, similar to the high elevation Tenerife CIDP's. How long that would potentially take is anyone's guess. 

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Xenon
1 hour ago, UK_Palms said:

Clearly the environment is a factor in variation, otherwise we would only have a fraction of the number of species available today. Look at Chamaerops for instance, which would have just started out as the basic green type in southern Europe perhaps 20,000 years ago. At some point that spread to north Africa and in order to combat the colder nights at higher elevation in the Atlas mountain regions, it has mutated and become the 'Cerifera' or Argentea type. This is now unique to that region. Some nights go below 5F in that region, so that form of Chamaerops has clearly undergone changes to allow it to become more hardy to survive there, compared to the original green version from southern Europe which cannot.

Likewise on some of the Italian islands, smaller, compact forms of Chamaerops have been found with different looking fronds, which cannot be found anywhere else. On one island where there are lots of feral goats, the Chamaerops are way thornier than average too with thorns on the fronds even, in order to combat the goats eating them. And those feral goats weren't introduced until the 1700's at the earliest, so the changes must have come about relatively quickly. If environmental factors weren't a cause for variation, we would just have the basic green type of Chamaerops and no others. However there are about 6-7 different sub-populations of Chamaerops now. It clearly also wouldn't be present in the Atlas mountains, but underwent changes enabling it to colonise that region about 5,000 years ago. There has been some genetic testing done to show this. 

@Xenon So you're saying that you don't think Washingtonia seed produced from survivors of the Texas freeze will result in more cold-hardy specimens in the future, potentially? So you are refuting that theory, right? Given that you say that environmental factors cannot influence cold hardy genetics. The same goes for the Truth or Consequences Filifera, which by your reckoning should be no more hardier than bog standard Filifera, right? Or are they actually more hardy because they came from survivors of previous freezes and have been selected for their tougher traits, creating hardier seed stock, whether naturally or through human intervention. Continued backcrossing should in theory result in hardier seed stock.

In which case, the idea of zone pushing borderline species, selecting the survivors and toughest specimens and then forcing them to set seed over a number of generations, in less than ideal climates, clearly must produce hardier individuals further down the line, since the weaker won't survive. It may even result in mutations and different species altogether, which is how different species of the same genus have ultimately come about. I am not saying that is definitely the case, but it seems extremely plausible to me. Take Dactylifera for instance, if it did morph into Theophrasti, Reclinata and CIDP as it expanded outside of its natural range. It probably morphed into CIDP to handle the wet-cold Atlantic conditions, especially on the windward side of the Canary islands and in the mountainous interiors. Again, I am just speculating on that though.

It's also interesting that the higher elevation CIDP's on Tenerife have fatter trunks and are supposedly more leaf-hardy by up to 5F. So there is almost certainly some evidence of more cold-hardier variations of the same species, dependent on climatic factors. I wouldn't be surprised if the UK born and bred CIDP's eventually form fatter trunks and more leaf hardy traits over a number of generations, similar to the high elevation Tenerife CIDP's. How long that would potentially take is anyone's guess. 

Correlation is not causation. The environment is selecting from the existing gene pool and/or chance mutation and the end product is the different forms of Chamaerops you mention. Variation is not arising de novo due to the environment. Mutation is entirely random (and usually deleterious, with the occasional exception), a plant cannot "will itself" to mutate in response to the environment. There are certain interactions (epistasis) that can occur between genes and the environment, but this concerns expression or silencing of already present genes. 

Concerning "pure W. filifera" in Texas, whatever survived XYZ low temperature just represents environmental selection from the already present genetic variation in W. filifera. The plant did not "acquire" or "will itself" the ability to survive an arctic blast, the genetic potential was already there. The Washingtonia hybrids in Texas are a more complex matter as not only do you have to account for the genetic variation present in both species of Washingtonia but also the degree of admixture in hybrids. The hybrids are not stable and from a single seed batch you will get progeny with varying degrees of admixture between the two species (and as a consequence, varying degrees of cold tolerance) due to recombination. Sure, you could select the most cold hardy forms with further inbreeding but you would probably end up back where you started by selecting against the W. robusta genes to get something that is more or less W. filifera. An interesting experiment would be to see much how cold tolerance from W. filifera you can confer to a hybrid while maintaining as much of the W. robusta phenotype as possible. It would take another 7-10 generations to stabilize a hybrid with the "magic ratio". 

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Xenon
On 8/18/2021 at 9:12 PM, Swolte said:

More recently there's been some more evidence that there are ways in which certain acquired traits can be passed on through the germline (e.g., epigenetic inheritance in yeast for a well documented one) at least for a number of generations, so its not impossible! 

Epigenetic inheritance is the passing on of gene expression and/or gene silencing i.e the genes are already present. It's not a novel source of genetic variation like mutation. 

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UK_Palms
6 minutes ago, Xenon said:

Correlation is not causation. The environment is selecting from the existing gene pool and/or chance mutation and the end product is the different forms of Chamaerops you mention. Variation is not arising de novo due to the environment. Mutation is entirely random (and usually deleterious, with the occasional exception), a plant cannot "will itself" to mutate in response to the environment. There are certain interactions (epistasis) that can occur between genes and the environment, but this concerns expression or silencing of already present genes. 

Concerning "pure W. filifera" in Texas, whatever survived XYZ low temperature just represents environmental selection from the already present genetic variation in W. filifera. The plant did not "acquire" or "will itself" the ability to survive an arctic blast, the genetic potential was already there. The Washingtonia hybrids in Texas are a more complex matter as not only do you have to account for the genetic variation present in both species of Washingtonia but also the degree of admixture in hybrids. The hybrids are not stable and from a single seed batch you will get progeny with varying degrees of admixture between the two species (and as a consequence, varying degrees of cold tolerance) due to recombination. Sure, you could select the most cold hardy forms with further inbreeding but you would probably end up back where you started by selecting against the W. robusta genes to get something that is more or less W. filifera. An interesting experiment would be to see much how cold tolerance from W. filifera you can confer to a hybrid while maintaining as much of the W. robusta phenotype as possible. It would take another 7-10 generations to stabilize a hybrid with the "magic ratio". 

I think you are overcomplicating the process, Jonathan. I totally get where you are saying, from a scientific point of view, but using big words and convoluted sentences doesn't make your point anymore valid. What I was implying is that the washingtonia's that survived the freeze will surely go on to pass on stronger, more cold-hardy genes to their offspring. That is how natural selection works. The hardiest and strongest survive and pass on their genetics, further reinforcing the bloodline. That is the case with all species, throughout history. That's not to say the next generation will be much different though, but superior genetics will be passed on, which will eventually result in major changes over a number of generations. 

In the native range, these acquired changes are less important and not an issue as plants or palms will not see abnormal temperatures or conditions in areas that they have lived for millennia. When you are introducing a species to an area that it is not accustomed to and then subjecting it to strenuous conditions outside of its comfort zone, you are going to ween out the tough ones from the weak ones, as well as the ones with more cold-hardy traits from the less cold-hardy ones. Those genetics will then be passed on through subsequent generation and reinforced under the same stressful conditions, which will eventually result in a different gene pool which has different characteristics and adaptabilities. Hence why there are so many different species of flora and fauna today.

The fact that there are so many different date cultivars too, just from a couple of hundred years of proper breeding, exclusively in hot-desert climates, shows this. If cultivators worked harder with Dacty's in cool temperate climates I am convinced there would be even more radical changes to the gene pool, certainly in terms of cold hardiness and looks (fatter trunks, bigger crowns etc). When the first Dactylifera's spread west to the Canary Islands, they probably struggled with the humidity, rainfall, wind and mountainous conditions. As a result, they developed fatter, stronger trunks, bigger more robust crowns, better wind resistance and a greater degree of wet-cold tolerance until they became the CIDP's that we see today.

I suspect it was possible to go from Dactylifera to modern day CIDP within 50 generations, or about 500 years, under such conditions. Possibly less time, depending on the extent of the mutations. The Dacty's would have been okay at sea level and on the protected leeward coasts, but gradual changes would have occurred to the Dacty's gene pool on the exposed windward coasts and inland mountainous regions where it was cooler, wetter and windier. Those changes eventually resulting in the CIDP's that we see today, which became the dominant palm in inland areas of the Canaries, which then started to outcompete the Dacty's even at sea level. Again, a lot of that is theory, but it seems very plausible. It will be a similar case with Theophrasti as well.

There is no evidence whatsoever that either of those two types were present before Dactylifera, especially when you look at genome decoding. So Dactylifera has clearly changed over time, as it has moved into new regions, becoming more hardy, especially to wet-cold. With human intervention, I would expect such changes to be amplified 10 fold with Phoenix types, such as the CIDP's being grown and self-seeded in southern England. The trunks may get fatter over a couple of generations, to increase bud-hardiness, and crowns may get bigger and fuller to absorb more sunlight in our northern location. If it has happened before in the Canary Islands, it will almost certainly happen again under even more strenuous conditions. I guess we will know in the coming decades and centuries. Or at least our grandkids will know. 

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Swolte

I think some of the confusion comes from whether we're talking about an individual palm or a palm species in general. I agree with Xenon that (if I understand him correctly), when speaking of individual palms, that cold resistance is largely dependent on the relevant genes the palms has been dealt. However, at a species/intergenerational level, propagating palms that survived cold snaps over generations can make hardier forms of palms across generations because there are ALWAYS natural levels of genetic variation within a species (e.g., caused by mutations). By propagating survivors, you increase the likelihood of propagating those mutated genes that cause better cold resistance. 

No one claimed (I believe) epigenetic inheritance was a novel source of genetic variation but it is a mechanisms through which certain 'adaptive' traits can be transferred to a next generation, based on experience during a lifetime, that could make an organism more resilient to certain environmental stressors. I am not sure there is any evidence for that in palms yet but it is theoretically possible.
 

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teddytn
54 minutes ago, Xenon said:

Correlation is not causation. The environment is selecting from the existing gene pool and/or chance mutation and the end product is the different forms of Chamaerops you mention. Variation is not arising de novo due to the environment. Mutation is entirely random (and usually deleterious, with the occasional exception), a plant cannot "will itself" to mutate in response to the environment. There are certain interactions (epistasis) that can occur between genes and the environment, but this concerns expression or silencing of already present genes. 

Concerning "pure W. filifera" in Texas, whatever survived XYZ low temperature just represents environmental selection from the already present genetic variation in W. filifera. The plant did not "acquire" or "will itself" the ability to survive an arctic blast, the genetic potential was already there. The Washingtonia hybrids in Texas are a more complex matter as not only do you have to account for the genetic variation present in both species of Washingtonia but also the degree of admixture in hybrids. The hybrids are not stable and from a single seed batch you will get progeny with varying degrees of admixture between the two species (and as a consequence, varying degrees of cold tolerance) due to recombination. Sure, you could select the most cold hardy forms with further inbreeding but you would probably end up back where you started by selecting against the W. robusta genes to get something that is more or less W. filifera. An interesting experiment would be to see much how cold tolerance from W. filifera you can confer to a hybrid while maintaining as much of the W. robusta phenotype as possible. It would take another 7-10 generations to stabilize a hybrid with the "magic ratio". 

That last statement might be what we’re all getting at with different ways to describe it. The magic ratio….the-insert palm name here- with the best genetics built for cold. Which may take genetic manipulation or just systemic breeding over generations or a combination of both. Everyone keeps hitting on genetic baseline being cut and dry, I feel like there’s room for improvement. I keep using dogs as an example, but if you took a husky and the Mexican hairless dogs and swapped them into the others environment the results would be the same as planting a palm where it has no chance of survival. You’ve mentioned a few times the variability that already exists genetically. With further human intervention I hope it’s possible to have an even cold hardier palm than we know of now. Pushing the limit to make a palm that is happy in the cold just like a husky is.

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Xenon
2 minutes ago, teddytn said:

You’ve mentioned a few times the variability that already exists genetically. With further human intervention I hope it’s possible to have an even cold hardier palm than we know of now. Pushing the limit to make a palm that is happy in the cold just like a husky is.

And selection from that variability has limits. Genetic improvement plateaus once you run out of new sources of genetic variation 

Corn, tomatoes, etc have been grown worldwide for centuries and are much more economically important than palms and they still can't take a hard freeze. Don't expect miracles! 

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teddytn

There’s a reason everyone buys up seedlings with cultivar names like Trachycarpus fortunei Bulgaria, Sabal palmetto Bald Head, Washingtonia filifera Oregon right…..I’ve been wrong about things before lol, I would bet money if there was a way to measure cold hardiness with a “test” those offspring would have a measurable difference even if very small over a run of the mill, in native range palm. 

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teddytn
1 minute ago, Xenon said:

And selection from that variability has limits. Genetic improvement plateaus once you run out of new sources of genetic variation 

Corn, tomatoes, etc have been grown worldwide for centuries and are much more economically important than palms and they still can't take a hard freeze. Don't expect miracles! 

This is all indulging fantasy anyways, outside of “us” nobody gives a rats ass about palms in general let alone cold hardy ones. I won’t hold my breath lol

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UK_Palms

This is probably the furthest CIDP from the equator in the world up at 54N in Scarborough, north Yorkshire on the far northeast coast of England. I think it was planted as a tiny seedling about a decade ago and has began flowering profusely in recent years. So far it is unfazed by any amount of cold or crappy weather, which doesn't stop it from flowering. It doesn't seem to really take any winter damage either up there, probably due to it's proximity to the coast. Just for a reference, this is more than 100 miles further north of the equator than Edmonton in Canada. I believe someone collected seed this year as well to send up to Scotland, for further trials. 

These pics are from 2020 I believe...

20210731_130756.jpg.c1959d76757834075bdc5f71b592686a.jpg

Scarborough-Phoenix-May-2020.jpg.2ca8278e9e34ca2d8741442c99462490.jpg

20210731_130619.jpg.65b06611396115f5607b0ae1939d6009.jpg

This picture is from way back in 2017 showing the inflorescence...

IMG_20171125_1245351036x1842.thumb.jpg.9f7bdd116b51884b4624255c871c3ee8.jpg

There is a rumour that this specimen came from seed stock in Cornwall, although I doubt that is true. Assuming this is a hardier than average specimen though, the genetics and resulting seeds will almost certainly be backcrossed into any experimentation into acquired cold-hardiness and reinforced bloodlines. If the resulting seeds can be germinated in Scotland and planted in the mildest location up there, protected during the early years and then further seed is cultivated from those specimens to further backcross, we could be onto something. I wouldn't be shocked if CIDP's start appearing around the entire UK coastline within the next decade, especially if tougher seed stock is produced. 

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Jimhardy

Its the ice crystals inside the palm that cause ruptured cells so yeah....ice crystals here,ice crystals there

here some ice, there some ice everywhere some ice ice baby.....old McDonald had a farm of dead palms.

 

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Yort

I have studied plant breeding and worked as a breeder at one of the worlds leading breeding companies in The Netherlands. I can confirm that Xenos is correct in the above posts.

Cold tolerance is a (genetically) complex trait, meaning that many internal processes work together to cope with the cold. However, I do believe that it is possible to create more cold tolarant lines (compared to existing lines in cultivation) by using traditional breeding techniques. One has to ask the question where did the cultivated palms of my area originated from in the wild? Usually palms were collected in places that were easy to reach and where fruit was abundant. Selecting palms in habitat from populations that are experiencing colder temperatures from for example higher elevations, latitude or inland locations would be the frist step to start with.  It is very nice to see that this is being done in the US with a.o. Sabal minor. Then elaborate testing of the offspring in a controlled environment. Cold induced ion leakage of tissue could assist for early selection in seedling stage. Then crossing the selected lines could further improve cold tolerance since they may depend on different protection mechanisms against cold, especially interspecific crosses are likely to benefit. Then again testing and selecting. The elite lines could be clonally propagated or one could choose to inbreed for seven generations to get genetically stable seeds.

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teddytn
1 hour ago, UK_Palms said:

This is probably the furthest CIDP from the equator in the world up at 54N in Scarborough, north Yorkshire on the far northeast coast of England. I think it was planted as a tiny seedling about a decade ago and has began flowering profusely in recent years. So far it is unfazed by any amount of cold or crappy weather, which doesn't stop it from flowering. It doesn't seem to really take any winter damage either up there, probably due to it's proximity to the coast. Just for a reference, this is more than 100 miles further north of the equator than Edmonton in Canada. I believe someone collected seed this year as well to send up to Scotland, for further trials. 

These pics are from 2020 I believe...

20210731_130756.jpg.c1959d76757834075bdc5f71b592686a.jpg

Scarborough-Phoenix-May-2020.jpg.2ca8278e9e34ca2d8741442c99462490.jpg

20210731_130619.jpg.65b06611396115f5607b0ae1939d6009.jpg

This picture is from way back in 2017 showing the inflorescence...

IMG_20171125_1245351036x1842.thumb.jpg.9f7bdd116b51884b4624255c871c3ee8.jpg

There is a rumour that this specimen came from seed stock in Cornwall, although I doubt that is true. Assuming this is a hardier than average specimen though, the genetics and resulting seeds will almost certainly be backcrossed into any experimentation into acquired cold-hardiness and reinforced bloodlines. If the resulting seeds can be germinated in Scotland and planted in the mildest location up there, protected during the early years and then further seed is cultivated from those specimens to further backcross, we could be onto something. I wouldn't be shocked if CIDP's start appearing around the entire UK coastline within the next decade, especially if tougher seed stock is produced. 

I have seen you post so many times the latitudinal location of spots in the UK. I just looked up a global map, and I realized how special of a place that is. Regardless of weather moderated by the ocean, everyone gets it. 54N is very close to the Arctic circle. Morocco is 31N…Tennessee is 35N…I get my winter lows and duration of cold combined with winter moisture and freak arctic blasts which we get almost yearly. Im outside in my yard almost everyday of the year, I get the weather here. I’m still scratching my head, something doesn’t add up here lol. Crazy really that palms like washingtonia and CIDP produce viable seed there at all to be honest. That says something to me. This hasn’t been brought up yet, a plant naturalizing in a given locale pretty much serves as notice that it’s comfortable enough there to birth offspring that the plant feels will survive (if you can’t handle plants making decisions sorry haha) and to me at least proves the offspring can be actually moved into less desirable conditions and most likely survive. 

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teddytn

@Xenon @Yort it’s possible people, myself included are confusing the mechanism with the result. When we refer to a genetic mutation, what role does environmental factors play in triggering this reaction, if any? Is there a possibility of genetically mutated cold resistance as a result from exposure to cold?

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DreaminAboutPalms

We’ve only really been growing palms in Texas for a hundred years or less so it’s really too early to tell. I doubt all of the Sabal subspecies were created in that time frame. If we stop importing Washingtonias from Florida and keep seed growing from old ones here that have survived freezes, over the course of 400 hundred years I wouldn’t be suprised if they are different looking than and more cold tolerant than ones coming from the desert. Same goes with the naturalized robusta in south Texas 

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UK_Palms
18 minutes ago, Yort said:

Selecting palms in habitat from populations that are experiencing colder temperatures from for example higher elevations, latitude or inland locations would be the frist step to start with.

Isn't that essentially what a few of us are saying though, that species will adapt to cooler temperatures at higher elevations or latitude in the wild. So the gene pool from ones in that location would be more resilient to cold than lower elevation or lower latitude specimens of the same species. Such as the Filifera populations in Utah, or the Santa Catarina mountain Queen Palms, or the fatter trunked CIDP's growing at the top of the Masca mountains in Tenerife. They all have slight variations in appearance as well as supposedly increased cold-hardiness, despite being the same species still.

I'm not going to pretend to fully understand plant genetics to the extent of you or Xenon do, but to me it is clear as day that higher latitude or higher elevation palms will adapt over a number of generations, to a degree. The differences are clear. In the wild it would be a very slow process as the species slowly creeps further north, or further up a mountain. With human intervention it would be a much quicker process with more extreme changes in a quicker timeframe since it is being forced more aggressively. That may still take several generations for any apparent change to be visible though, assuming they do happen. 

How did CIDP and Theophrasti come about if the original Phoenix ancestor didn't change/mutate over a number of generations as it moved into new territory? Why is Phoenix Reclinata and Rupicola only hardy down to 20-25F when CIDP's and Theophrasti can take 0F and come back? Shouldn't all the Phoenix's in theory have the same degree of cold-hardiness if they all originated from Dactylifera, or some other common ancestor. Or do palms adapt, change appearance and hardiness over a number of generations when they move into new areas, potentially creating new species? Genuine question. It's an interesting topic and discussion. 

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Swolte

 

3 hours ago, UK_Palms said:

Isn't that essentially what a few of us are saying though, that species will adapt to cooler temperatures at higher elevations or latitude in the wild. So the gene pool from ones in that location would be more resilient to cold than lower elevation or lower latitude specimens of the same species.

Agreed. I am not sure I can put my finger on the disagreement. It seemed, at first, like Xenon was suggesting that increased hardiness is not possible as "the environment (or people) can only select from existing variation in the population", which may be interpreted to say that a population would then never be able to create novel sources of variation. Not sure that is what he meant as this goes counter to main theory of natural (and unnatural) evolution. There are always sources of variation from generation to generation although, if environmental pressures are stable, for example, it is unlikely any mutation will bear an advantage to be selected upon. However, in the next sentence Xenon clearly says "Barring mutation, gene flow, or genetic engineering, you aren't going to significantly improve the hardiness of a palm beyond the existing natural variation in hardiness. " which is precisely the argument we have been making all along. 
:P
Anyway, I don't really see a contradiction. I think Xenon was just trying to make the (correct) point that it is a very hard and painfully slow process to increase palm hardiness through random mutations.  Correct me if I am wrong.

 

4 hours ago, teddytn said:

When we refer to a genetic mutation, what role does environmental factors play in triggering this reaction, if any? Is there a possibility of genetically mutated cold resistance as a result from exposure to cold?

Well, I think the standard, and possible best, answer is no.

Having said that, some humility is in order. We are learning a lot about how certain mechanisms of epigenetic inheritance may have an indirect influence on evolution. Increased levels of methylation (one mechanism of epigenetics) have been linked to increased mutation frequencies, for example. Further, methylation can also mess with repair genes. Each of these can lead to permanent genetic changes in targeted regions of the genome that aren't completely random. 
I worked in a genetics department some 15 years ago (albeit human genetics) in the Netherlands so I am a bit rusty and the epigenetic stuff is very new! We're talking the edge of science here and there is no evidence that this works for genes involved in hardiness in palms nor that its effects are large.

 

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Xenon
1 hour ago, Swolte said:

 

Agreed. I am not sure I can put my finger on the disagreement. It seemed, at first, like Xenon was suggesting that increased hardiness is not possible as "the environment (or people) can only select from existing variation in the population", which may be interpreted to say that a population would then never be able to create novel sources of variation. Not sure that is what he meant as this goes counter to main theory of natural (and unnatural) evolution. There are always sources of variation from generation to generation although, if environmental pressures are stable, for example, it is unlikely any mutation will bear an advantage to be selected upon. However, in the next sentence Xenon clearly says "Barring mutation, gene flow, or genetic engineering, you aren't going to significantly improve the hardiness of a palm beyond the existing natural variation in hardiness. " which is precisely the argument we have been making all along. 
:P
Anyway, I don't really see a contradiction. I think Xenon was just trying to make the (correct) point that it is a very hard and painfully slow process to increase palm hardiness through random mutations.  Correct me if I am wrong.

 

Well, I think the standard, and possible best, answer is no.

Having said that, some humility is in order. We are learning a lot about how certain mechanisms of epigenetic inheritance may have an indirect influence on evolution. Increased levels of methylation (one mechanism of epigenetics) have been linked to increased mutation frequencies, for example. Further, methylation can also mess with repair genes. Each of these can lead to permanent genetic changes in targeted regions of the genome that aren't completely random. 
I worked in a genetics department some 15 years ago (albeit human genetics) in the Netherlands so I am a bit rusty and the epigenetic stuff is very new! We're talking the edge of science here and there is no evidence that this works for genes involved in hardiness in palms nor that its effects are large.

 

The main point I'm refuting is that "the environment causes variation/mutation". Mutation is an entirely random process due to errors in DNA replication, DNA damage from exposure to radiation or chemical agents, etc. Growing a date palm in London is no more likely to cause a mutation for increased cold tolerance than growing a date palm on the Nile Delta. The environment can only select for a positive mutation if said mutation occurs purely by chance. The environment has no bearing on the nature of a random chance mutation. 

So at this point you are left with the more pragmatic option of selecting from existing variation or waiting for the extremely low chance of a specific mutation that confers greater cold tolerance that isn't deleterious in some other way. Once you hit the plateau of improving cold tolerance through selection from existing variation, "you're" probably going to be waiting millions of years/forever for a miraculous aligning-of-the-stars mutation that brings you another inch forward. It's not an exponential curve of "this palm survived 10F so the progeny will be more hardy and their progeny even more hardy and so on and so on". 

I guess the main takeaway is that perhaps you could breed another 1-5F of cold hardiness with intensive selection of the most cold tolerant populations but anything beyond that is probably wishful thinking. 

I forgot to mention another source of novel variation: horizontal gene transfer between species which in the case of plants mostly occurs via a viral or bacterial vector. 

Full disclosure: I'm a graduate student studying plant breeding at your local university. 

Edited by Xenon
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Yort
2 hours ago, Xenon said:

The main point I'm refuting is that "the environment causes variation/mutation". Mutation is an entirely random process due to errors in DNA replication, DNA damage from exposure to radiation or chemical agents, etc. Growing a date palm in London is no more likely to cause a mutation for increased cold tolerance than growing a date palm on the Nile Delta. The environment can only select for a positive mutation if said mutation occurs purely by chance. The environment has no bearing on the nature of a random chance mutation.

Mutation is indeed random and environment does not cause specific mutations. However environment do cause selection on specific favourable traits over generations.

I believe that by selecting in habitat or from cultivated populations that are at least a few thousand years old one can greatly improve cold tolerance compared to lines that are currently commercially grown.

@UK__Palms

The Masca population of Phoenix canariensis on Tenerife is certainly not more tolerant to cold compared to other Tenerife populations or cultivated canariensis in Europe.

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UK_Palms
32 minutes ago, Yort said:

The Masca population of Phoenix canariensis on Tenerife is certainly not more tolerant to cold compared to other Tenerife populations or cultivated canariensis in Europe.

I’m sure I remember a study where they tested the high elevation Masca population in Tenerife against low elevation specimens, as well as some others from the island of La Gomera. All 3 populations had different genetic profiles when examined, as well as slight variations in trunk girth and height, differences in leaf hardiness and seed size/shape/colour. I think they theorised that the Masca population, or high altitude CIDP’s in general on Tenerife, had changed over time to be more cold-hardy and better adapted to a high altitude climate. Whether or not that is true is up for debate as the study was done in the late 90’s I think. I can’t find the source for the study to post either, so we will consider it unverified and unproven. 

However what are your thoughts on the Porphyrocarpa (red fruit) variation of CIDP? I know people say it’s a hybrid with Dacty or Sylvestris potentially, but I have also heard that this red fruit variation was first discovered in the Canary Islands and is possibly the result of a mutation or even a separate subspecies? There are also claims that Porphyrocarpa are about 5F more cold-hardy and better suited to wet-cold climates than traditional CIDP. They look almost identical to CIDP, minus the fruit colour and fruit size and potential increased hardiness. I have no evidence of this per say, but I suspect you know what I am referring to. Has this ‘red fruit’ variant been studied or tested? Is it a different variant of CIDP or a hybrid in your opinion?

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Yort
1 hour ago, UK_Palms said:

I’m sure I remember a study where they tested the high elevation Masca population in Tenerife against low elevation specimens, as well as some others from the island of La Gomera. All 3 populations had different genetic profiles when examined, as well as slight variations in trunk girth and height, differences in leaf hardiness and seed size/shape/colour. I think they theorised that the Masca population, or high altitude CIDP’s in general on Tenerife, had changed over time to be more cold-hardy and better adapted to a high altitude climate. Whether or not that is true is up for debate as the study was done in the late 90’s I think. I can’t find the source for the study to post either, so we will consider it unverified and unproven. 

However what are your thoughts on the Porphyrocarpa (red fruit) variation of CIDP? I know people say it’s a hybrid with Dacty or Sylvestris potentially, but I have also heard that this red fruit variation was first discovered in the Canary Islands and is possibly the result of a mutation or even a separate subspecies? There are also claims that Porphyrocarpa are about 5F more cold-hardy and better suited to wet-cold climates than traditional CIDP. They look almost identical to CIDP, minus the fruit colour and fruit size and potential increased hardiness. I have no evidence of this per say, but I suspect you know what I am referring to. Has this ‘red fruit’ variant been studied or tested? Is it a different variant of CIDP or a hybrid in your opinion?

I would love to read the study that you mention about the Masca population. However the claim that the Masca population is more tolerant to cold compared to other populations on Tenerife contradicts my own results. In the tests I conducted all tested Tenerife populations showed similar cold tolerance.

Porphyrocarpa is a regular canariensis that has a genetic variation causing red colour of the fruit. I havent seen any evidence that this trait is linked to improved cold tolerance and I think it is highly unlikely. As to the origin of this trait, this is only guessing, it may be a random mutation or a trait that introgressed into the line from interspecific crossing generations back. I believe that nearly all canariensis in cultivation today have at least some foreign genes and almost non are completely pure. Even the ones growing at Masca are not 100% pure. I can give you a definitieve answer about Porphyrocarpa cold tolerance in december this year since I will be testing a few hundred seedlings in the lab.

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DreaminAboutPalms

We’re really only searching for a couple more degrees of hardiness in central Texas. All these palms do great 362 days a year it’s the freak wet cold snaps that kill off the weak ones. And there’s seems to be a big difference in hardness between individual specimens and it can’t be explained by size or planting location or wind exposure. 

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amh
On 8/23/2021 at 10:52 AM, Xenon said:

The environment (or people) can only select from existing variation in the population. The environment itself is not the cause of variation. Barring mutation, gene flow, or genetic engineering, you aren't going to significantly improve the hardiness of a palm beyond the existing natural variation in hardiness. 

Outside gene flow from hybridization is probably the most realistic avenue for increasing cold hardiness without splicing genes manually or shooting X-rays and hoping for the best. In theory, you could transfer genes for cold tolerance from a more tolerant species to a less tolerant species (ex: Butia odorata -> Syagrus romanzoffiana) via repeated backcrossing (introgression) to create something that is nearly "pure" Syagrus romanzoffiana with the introgressed gene(s) for greater cold tolerance. This is assuming you could identify the gene(s) responsible for cold tolerance, isolate and express it in a way that doesn't affect the phenotype (appearance) of your desired outcome i.e a pure looking Syagrus romanzoffiana. However, it's likely that cold tolerance is polygenic and tied (or synonymous) to other genes that affect phenotype (such as leaf thickness, wax production, etc). 

Palms cannot "acquire" cold tolerance, a more cold tolerant specimen represents already existing variation. Some palms like Syagrus romanzoffiana and Bismarckia nobilis have relatively high genetic variation to cold tolerance vs palms with very low variation (most lowland equatorial species). Also, it's incredibly difficult to "control" for genetic tolerance vs outside factors such as crown height, soil moisture, soil biology, etc. 

 

Can you recommend any chemicals for inducing mutations at home?

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Yort
8 hours ago, amh said:

Can you recommend any chemicals for inducing mutations at home?

Ethyl Methanesulfonate (EMS) is used to treat seeds for triggering mutation but you should never use this at home. It causes mutations so it is very dangerous and can easily cause cancer.

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amh
9 hours ago, Yort said:

Ethyl Methanesulfonate (EMS) is used to treat seeds for triggering mutation but you should never use this at home. It causes mutations so it is very dangerous and can easily cause cancer.

So, nothing I can pour down the sink?:P

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