Plant Acclimatization

I posted this topic in the GardenWeb forum and would like to seek more opinions on this matter especially from those specialized in genetics.
Here by acclimatization I am implying that a deciduous plant can adapt to survive in tropical conditions. I have known of certain species of deciduous plants which have been successfully cultivated in the tropics. The best example is the Wrightia religiosa which is the favorite plant for bonsai in South-East Asia. It has adapted to do without winter dormancy and as a result it does not flower unless you defoliate the plant completely. Also many types of temperate evergreens have survived the tropical heat like the pines and others too.
Now the point I am looking for is whether the modifications or adaptations have become inheritable traits for its progeny. I believe they are inheritable, as the seedlings grown from Wrightia religiosa mother plant cultivated in the tropics show they thrive in a tropical environment, without the stress and modifications which their temperate ancestors have had to undergo. In fact when these seedlings are grown in temperate climate, they do poorly and their growth is incredibly slow. Thus it can be inferred that there must be changes in their genes when they have become acclimatized to a tropical environment. I greatly appreciate if anyone can shed some light on this point.

 

Plants have been here much longer than us, and have seen many changes in their environments, it stands to reason that many would still remember in their gene's what to do when under differing conditions, if they do not they die, or become a very small part of the flora. Seed plants especially have to remember in their gene's, to be able to pass on the information. When a plant is moved out of its, todays favorite environment, it has to slowly adapt, by by making the gene's needed more dominant, to deal with its new found environment.
rough science 101.

 

Yes: individual specimens do not adapt. Each one comes with predetermined parameters outside of which it will not function well, if at all. To see adaptation to new conditons you have to wait for a species to evolve it.

 

I have and perhaps others too, experimented with borderline hardy seedlings. Grown under indentical conditions, some fail within the first year, others the second. Some manage to pull through and exceed the known limits of hardiness and stresses not normally encountered over time. Adaptation without evolving? It's not exactly what jamkh is speaking of in the initial post, but similar to the point where some will survive where others of the same seed batch and condtions don't.

Cheers, LPN.

 

Ron & LPN
If getting the plant to modify and respond to tropical conditions is slow and difficult, then it may be better to resort to hybridization. Here breeders have succeeded to bring forth hardier hybrids by selective cross and back breeding to accentuate the the gene carrying the hardiness trait to become dorminant. So in this case breeders can activate the dormant gene that constitute less hardiness to become dorminant. Thus the process is a direct reversal of what they had already done. An interesting idea I would say.

 

If some seedlings live and others don't, those came with different built-in parameters. The survivors did not 'adapt' to the new environment.

 

Ron,
A plant with its unique genetic make-up has its own built in parameters. But these parameters are not rigid like prison bars but rather pliable/stretchable. It is this elasticity that makes acclimatization possible. Acclimatization is not just limited to the moderations to accomodate the heat or the cold, it covers a whole range of plant attributes.
Why I just read the thread by Tweetie that she dung her bonsai tree and pot into water, let it sit there for an hour and then take them out.
Of couse everybody would claim that that's not a good way to water your bonsai. But I am positive that her plant is happy with her way and it looked no worse with that treatment. What I am inferring is that her plant has become acclimatized to her way. As long as both are happy who are we to pass judgement; as Shakespeare puts it "to each his own". Tweetie, I suspect you're a non-conformist, so just continue to do it it "MY Way" HeHeHe.

 

Tweetie's bonsai has not 'acclimatized' to the dunking treatment, it is tolerating it. As long as the thresehold at which rot root or root drowning occurs is not reached, the plant will be fine. A good analogy would be dunking yourself underwater....you are able to tolerate it but you don't somehow become more physiologically capable of staying underwater longer. You could 'train' for it by increasing your fitness level, but that increases your tolerance of the situation only by a very small %.

Both you (Jamkh) and Ron are correct in your thoughts regarding a plants ability to 'adapt' to a cultural condition.

Ron's statement that plants have genetic "built-in parameters" is correct and that allow plants to tolerate a range of cultural conditions. If the plant experiences conditions outside of those parameters, it will die, not adapt.

Your statement on 'adaptation' is also correct but you often seem to apply it to situations that constitute major cultural changes beyond what the plant "built-in parameters" can tolerate. Plant 'adaptation' to a situation consitutes minor structural changes to minor cultural changes. It might include root structure & density variations caused by soil structure or water availabilty, crown structure influenced by light or wind, trunk thickness by wind, etc. All these 'adaptations' are pre-existing "built-in parameters" that allow the plant to be competitive within it's environment but require years to establish. Major cultural changes, (major drought, waterlogging, extreme cold, lack of nutrient, etc.) beyond the allowance of the "built-in parameters" will cause the plant to die, not 'adapt'.

I believe Daniel refers to it as "phenotypic plasticity" and some plants have it more than others.

I really like that phrase "built-in parameters"
Simon

 

"built-in parameters" ?

Here's an example of exceeding known parameters.
In the spring of 2004, started 50 fresh Phoenix caneriensis seed sent to me from a friend in California. All 50 germinated and where potted up into 2 gallon pots. As an experiment, I left them out over winter in our rainy and sometimes cold climate. These poor seedlings where put to the test on one night when temps dipped to -7C (19.4F), and where treated to a couple of slushy snow falls as well.
The following March I was doing some spring cleaning around the yard. I spotted my dead seedlings and was amazed to find 2 seedlings still alive. How could these manage to have survived these extremes while all the others perished? What sets these 2 apart from the rest, and how where they able to survive beyond the known limits?

Cheers, LPN.

 

Genetic variation.

 

LPN
I had encountered your experience more than once already. It is the genetic diversity existing in seeds that first fired my interest in botany 5 years ago, prior to which I had never lifted a finger in any garden.
Rather than accepting the norm or proven path, I prefer to walk on unproven grounds, just because I like the unexpected. Your case proves my claim that these built in parameters are pliable and allow a small percentage of plants to go beyond their limits of endurance. In hybridizing hosta, I already had come across one where it is able to delay its flowering until the following spring. Not probable you may say but it has been achieved already. As I continue digging in I am hopeful to get more surprises from nature; maybe a blue rose...Haha.

 

There is no [WIKI]exceptionalism[/WIKI] in the case of LPN's seedlings.

Something exceeding "known parameters" does not mean something miraculous has occurred. It only means that the "known parameters" were incorrect, and new "known parameters" have become known.

Similarly, plants cannot exceed the limit of their endurance and survive. Only three possible scenarios exist:

1) They go beyond their limit of endurance and die
2) They reach their limit of endurance
3) They do not reach their limit of endurance

 

Daniel,
I stand corrected, I should have used this term "....and allow a small percentage of plants to go beyond the ( normal known) limits of endurance. You use the term, phenotypic plasticity, but I would prefer to call my case as 'phenotypic elasticity'.

 

By the very nature of our planet, all plants must carry a certain flexibility.

Plants must be able to adapt but within the limitations of evolution, with the information they were given by the previous generation, and to pass on the very slight adaptations to the new generation would be evolution.
They must pass on adaptations or there would be no evolution........each new generation would just be growing on its limits like its parents.

so my answer would be yes they must be able to adapt.

 

or 4) God steps in and gives them a helping hand, allowing them to exceed their known limitations

 

Well, the discussion has now shifted beyond the realm of the sciences of botany and horticulture, so it's gone beyond the scope of these forums. Closing the thread.