Terminology question

"Clone" is a very loose term when it comes to orchids and I think it can be used to refer to any orchid (noun). An orchid that is made by asexual propagation is a cloned orchid.(verb)

Any orchid can have a varietal name or a name in single quotes - usualy referred to as the clonal name. Any orchid, that is asexually propagated, should have the same name as all others with the same exact genetic background. Thus any orchid can and may be referred to as a clone, but not all orchids are cloned. Now I'm confused!!!

It's my understanding that alba means a lack of purple.

I always thought that sib cross was a crossing of two orchids from the same parents (both).

 

Latecomer to this thread, but here goes...



The origin of the word clone is a Greek word for twig. Use of the word clone (or clon, in early use) predates laboratory techniques in micropropagation by several decades at least. Both those facts should be strong clues that it does not just refer to laboratory procedures or the clones that result from them.

It first referred to a cutting (twig) and the plants resulting from propagation by cuttings – a purely horticultural use. That use can be traced to the very early 1900s in writing, but may have existed as a connotation of that form of the Greek word from much earlier. Botanists adopted the word as a term for plants and fungi resulting from the many asexual reproduction mechanisms occurring in nature. In both horticultural and botanical uses it has always been both singular (one such plant) and plural (the whole population resulting from propagation from a single original) – one clone or the whole clone.

Other biological sciences have also expanded the use of clone – you can clone cell lines, genes, antibodies, etc. It wasn’t until laboratory processes were in use in the 1950s that the word cloning really came into use, and clone became a verb as well as a noun.

A modern understanding of genetics ties the word clone to a unique genotype – an original organism and all the genetically identical copies, collectively and individually. In orchids this makes all cultivars clones no matter how the plants are propagated, though clones are not necessarily a cultivar unless someone gives them a name or designation. Even before a plant is ever propagated it is correct scientific usage to refer to it as a clone – a unique genotype - even though it is a single individual for the time being. Any plant with multiple viable meristems has already virtually cloned itself, and if you divide or take a cutting it is arbitrary to designate one as the original and the other as the clone, and if you could the original is definitely part of the collective clone.

 

Agreed!

 

Hi all just to throw another view in? (was a plant nurseryman for 40years) A 'Clone' refers to a seedling, so in each seed pod the seedlings each represent individual clones. Clones can only be produced by seed ie they are genetically distinct.
The term 'meri-clone', comes from the technique of mass reproducing one individual clone by dissecting out the meri-stem (growing tissue in the apical (shoot) tip under sterile conditions & getting it to grow on artificial medium, then dividing the tissue up into many new tissue clumps which under the conditions will form plant-lets each identical to the original clone.

Hence from a seed pod of geraniums which produces red, white, pink seedlings is where we get the red clones, pink clones & white clones etc., though if the plant is to be propagated in mass so that we have lots of red clones then one red seedling is selected & the meri-stem is cut out & grown on medium hence many plants all identical r produced with the red flower.

'Alba' in flowers & animals refers to; the recessive colour form of a given colour gene set. example in the (bird) budgerigar gene pool the wild type is green though due to continuous breeding a separation in the base colour occurred where blue budgerigars appeared. The blue budgerigar is considered to be an alba form of the green wild type bird.

Though due to continuous breeding many colour forms r now available & hence when u remove the blue gene from the green budgerigar it will give yellow which is considered to be an alba form, while if u take the blue gene out of the blue budgerigar then the alba form is white.

Alba forms r relative to the gene pool u r playing with, it is possible to have many alba forms in the same colour gene pool.
The alba form of a green budgerigar is yellow hence yellow birds r produced from green or green allied gene pool, while the alba form of Blue budgerigar is white etc.,

In flowers the same is noted as being an alba or alba marginata in foliage refers to the absence of green &/or pink pigment in foliage, or alba in the Paphiopedilum insigne is yellow, this means the base colour is yellow when u take away the brown or pink pigments, though in lavender cattleya gene pool an alba clone will be white as this is the base colour while the darker purple to red in lip may have a yellow base colour hence an alba cattleya refers to a white flower with a yellow spot in the flower lip.

The following images may help with my description;

 

This last part is an interesting and deep thought. Basically, the sporophyte in plants (or organisms with haplodiplontic life cycle) is a mean (or vehicle) to make multiple copies of the zygote. During the transition from water based life of algae to the land plant, producing the zygote becomes a challenge. This point gets well illustrated by considering how the lifecycle of bryophytes are. Even though they live on land, the sperm has to swim in the water to find eggs. So forming a zygote becomes challenging (compared to aquatic life). It is advantageous if one successful zygote can be multiplied by mitosis. So this might be one of the reason why all land plant adapted the haplodiplontic life cycle. So mitosis is cloning the genetic materials in zygote by producing near exact copies as you said.

But at the same time, it seems to be a bit twisted view. As we all know that there are several modern usages of clones, but in orchids, we are talking about clonal "reproduction", right? Reproduction produces self-sustaining individuals. Let's say that you decide to cut off one of your ear. From your definition, would you call this detached organ a clone of yourself? I wouldn't, unless a separate copy of you is produced from the ear. Plants are modular, so they have potential to create clones. But unless they are separated into different individuals, they share the fate, and all of the meristems coordinate the growth of the individual as a unit. Once they are separated, the behavior isn't the same.

I'm most familiar with ecology, genetics and evolution, but I'm pretty sure most biologists would use "genet" to mean the unique genotype. So a genet is a collection of ramets (which is same as clones), which shares the identical genotypes. They wouldn't use "clone" in place of "genet".

 

allanladd - I think we are in agreement. There are 2 distinct uses of the word clone as a noun. The copy - the more pop culture meaning of the word, specifically the result of "cloning" - but also close to the original meaning, the cutting and the plant grown from it. And the distinct genotype - singular or in all its copies - the modern scientific view. The original of a clone can only arise through sexual reproduction or mutation. Confusion arises when some with the pop culture view don't understand that.

noaki - Genet and ramet are correct, of course, but if referring to a grove of poplar trees or a fairy ring of mushrooms a botanist or ecologist would use the word clone in my experience, and the significance would be the origin from the first of the shared genotype. A molecular biologist would see a DNA sequence being replicated in many copies in a similar way. And the original would have to be the same clone. For any orchid, if it lives long enough it can have multiple active growing points, which will eventually be distinct plants as older tissues die out, or a slug or falling tree branch severs the connection. It exists as multiple members of a clone. If we see that random falling tree branch as a significant event in the existence (or not) of a clone, then the discussion may be more about existential philosophy or the theoretical physics of linear time than about biology.

The severed ear is a false analogy. Multiple viable meristems in the plant were already assumed. But slice a cancerous growth into halves and both are still viable, and composed of cells of the same clone that already existed.

 

PaphMadMan, I understand what u r talking about, though it is all getting a bit busy so will leave this forum up to all u enthusiasts. Thankyou

 

AAAAHHHHH!!! ORCHID INFO OVERLOAD!!!


There I contributed my opinion to the thread lol

 

When you think about a grove of poplar, you are right, I can see that people do use clones in place of genet (and I casually use it, too). But I started to wonder if it is the correct way to use it, and now I'm not completely sure which is correct.

Well, even if plants have multiple meristems, some plants don't produce individuals from each meristem, right? Some annuals are difficult to produce cuttings. You could clone with some meri-cloning. So it is similar to the ear cutting (with enough technology, we might be able to produce cloned human from a ear).