Apparently repeated meristem propagation affects plant quality - how does this work?

[Diane56Victor]

Originally Posted by camille1585

I hate shoddy translating jobs....
I don't know if we'll ever be sure of what he was really trying to say. I did find the guy's email address but I'm hesitant to bother a probably very busy person (he's the director) for a silly matter. It seems like a really big company, they have 2 sites with 14000 and 25000m2 (150000 and 270000 sq ft!) of greenhouses.

Im sure the director would be happy to find someone interested enough to make contact with him about his interview. Even if he doesn't have the time to answer himself Im sure he could pass on your question to someone who can help.

I would be very interested in hearing their answer.

[SouthPark]

Originally Posted by camille1585

I can't find more information about this though, and I'm curious to know how repeated meristeming causes a hybrid to degenerate. Anyone know?

It is a very good question. It's possible that nobody actually knows for sure at the moment.

In order to satisfactorily answer that question, workers would first need to do extensive DNA testing on the original plant (#1 plant) - to get its DNA map very accurately and precisely - that's if they can.

And then the testing could begin on meristem propagation.

They would have to grab first generation clones (where each 'clone' must be tested to ensure that it indeed is a clone - meaning exact DNA match with '#1'), and then perform meristem propagation on those gen 1 clones.

That results in gen 2 plants. And from the gen 2 batch, they need to grab sample plants and then DNA test them - in order to select gen 2 clones. And those gen 2 clones need to be propagated by means of meristem propagation.

And then they will have to define 'quality'. As in - if they have enough time on their hands to grow and flower every sample clone from gen1, gen2, gen3 batches ....... then they could do studies on 'quality' (eg. flower quality/appearance).

Now, if the DNA is known in advance to be identical for all those 'tested' plants ------ then they would be all clones. And having identical DNA would lead us to assume that the 'quality' is expected to be the same for clones.

And by 'clone', we mean exact DNA match.

Anything that doesn't have identical DNA match with #1 is not a 'clone'.

So unless there is any formal work done that goes through the steps of DNA testing etc, then there's nothing substantial or solid to go by - in terms of comments about 'degradation in quality'.

[My Green Pets]

On a related note, does anyone know of any labs that will do meristem cloning here in the US?

[estación seca]

Originally Posted by My Green Pets

On a related note, does anyone know of any labs that will do meristem cloning here in the US?

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[JScott]

Originally Posted by My Green Pets

On a related note, does anyone know of any labs that will do meristem cloning here in the US?

Laboratory Services – Gallup & Stribling

---------- Post added at 10:41 AM ---------- Previous post was at 10:34 AM ----------

Originally Posted by SouthPark

JS - I'm thinking that the chance is relatively high for getting a clone (ie. identical DNA as plant #1, where #1 means the very first original cultivar) from a cloning attempt process done on a CLONE (identical DNA to #1).

So you either received a clone (exact DNA match), or ....... if any mutation is present, then the traits you're looking for are still there, which is great. You probably got a plant with exact DNA match.

I love that peach colour. Fantastic!

Yeah, that's a very old hybrid, and I find it unlikely that it was cloned from the original mother plant, but i do believe that was cloned form a perfect clone of the original plant, and came out as a perfect clone itself (or like you said, any mutations are minor and do not affect the plant in any way) because it does look exactly like the original Serendipity, not the pink ones you often see now.

[donna133501]

I remember (many,many years ago), we did a lab experiment in college with gibberellic acid...too much or too little created all kinds of oddities, as did the stage of multiplication when it was applied.The one thing I remember was a seedling with a super long stem, it was unable to stand upright as the growth was so spindly.
So..I assume that any type of hormone, as in keiki paste, would be capable of inducing a mutation. The part that I don't get is why that would happen after multiple replications.

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Every cell division carries a low chance of mutation. Not all mutations cause an easily seen change in a plant. Orchids normally grow slowly, so the chance of a mutation is low across time. The chance of a mutation causing something a grower can see is even lower. Sometimes single mutations are noticeable, such as a different flower color.

With cloning, the amount of cell division is vastly higher than with normal orchid growth. A Cattleya that might be divided with a knife every 5 years could produce 2 plants after 5 years; 4 plants after 10 years; 8 plants after 15 years, and so on. Every time the plant makes a new growth there is a chance of a mutation happening. Sports do occur during normal growth, but they are rare.

With cloning, one can have thousands of tiny plants within a year. They are then grown out for a few years until they flower. It is as if decades of growing and dividing plants could be compressed into a brief time. There is a greater chance per unit of time to for visible mutations to occur in this huge population of cloned plants, as opposed to the small population of divided plants.

Various plant hormones needed for cloning may predispose to mutations occurring. Hence the frequency of mutations may be higher in cloned plants than in plants propagated by division.

As mentioned cloned plants may have non-visible mutations. If a clone with such a mutation or mutations is selected for repeat cloning, it will preserve the unseen mutations it came with, and some of its progeny will have further mutations. Eventually these mutations may interact to produce something the grower can see - different flower or leaf color, different vigor, different fertility.

If clones are cloned, and their progeny cloned, and cloned progeny cloned again, there will eventually be a lot of mutations in the population of clones.

This is why it is better to buy a clone made from the original plant. In some cases all the divisions of the original plant are dead, and all that are available are clones. In this case, try to get a division of a plant from the first generation of clones. Next best would be a clone made from the first generation of clones.

Some companies are careful to give this information. I mentioned Carter & Holmes elsewhere today; they provide this information. I have heard Daryl Venable of Tezula Plants, who specialized in Tolumnia, say that the company Jairak is careful only to clone their Tolumnias from divisions of the original plant. Other companies do serial cloning of Jairak plants, though, so you need to be careful of where they originated.

[SouthPark]

This is a really good thread. And it also brings up issues with words like mericlone and clone - since even though the words are used to describe all (every) orchids from a batch of orchids resulting from a meristem progagation process ----- the word 'clone' should probably be only used to refer to individual orchids that have identical DNA (to the #1 original orchid).

[estación seca]

To tell whether orchids have identical DNA one would need to sequence completely the nuclear and all organelle DNA. That's just not going to be done for cost reasons. In the plant kingdom "clone" refers to all plants propagated vegetatively from one plant. "Mericlone" refers to a clone made by culturing meristematic tissue from plants. Mericlones are a subset of clones. When people divide orchids we are cloning them.

Many Phals can be propagated (cloned) from the meristems left in flowering stem nodes that have not produced either a flower or another stem.

[SouthPark]

True ES. They probably either need to define 'clone' in discussions - from the beginning - to make sure that they really do mean 'clone'. Or if they don't mean orchids with a necessarily identical DNA match, then they definitely need to come up with a new word for mericlones that have identical DNA.

But definitely that is the issue ----- the uncertainty about whether the 'clone' is a clone (identical DNA) is the issue. That's due to the lack of cheap and reliable and quick DNA testing methods for the orchids.