Cultivar vs. Clone?

[kavanaru]

Originally Posted by Andrew

Ray,
The term clone is a biological term to refer to any organism that is reproduced by asexual reproduction. The term can legitimately be applied to any asexually reproduced plant both in cultivation and in the wild including keiki's and divisions. It's a descriptor of the genetic combination of the asexually reproduced plant group, akin to how cultivar is used for cultivated plants, with the individual clone being referred to as a ramet.

The term mericlone, which is usually shortened to clone, specifically refers to a clone that has been produced by micropropagation of the meristem. It's still legitimate to call keiki's, divisions, etc clones. They just can't be called mericlones.

While people refer to cultivars as clones and vice versa the two terms are not strictly interchangeable. Cultivar can't be used for wild clonal populations and in non-orchid areas of horticulture where cultivars can be sexually reproduced (such as in annuals) the use of the word clone would be inappropriate.

:Really picky pain in the backside pedent who places too much emphasis on semantics: (just in case the admin ever make that emoticon)

Thanks Andrew, while reading Ray's post I was going to provide teh same explanation. But you have been quicker than me and did in a fantastic way

I can only add that in-vitro clining does not necessarily need to be with meristematic tissues. You can use other tissues for in-vitro cloning. However, using meristematic tissues is the easiest method, and therefore widely used commercially in horticulture. Furthermore, meristematic cloning, when done correctly, can also be used to ensure virus free plants, and the rate of growth of meristem tissues is faster than the rate of tissue invasion of viruses (Note: Doing this is also not very easy as you need to use only the very very very apical cells of the meristem, and probably will need to do it a couple of times to achieve the desired result)

[Bolero]

This is a really worthwhile discussion, thanks for bringing it up!

[Andrew]

Originally Posted by kavanaru

Furthermore, meristematic cloning, when done correctly, can also be used to ensure virus free plants, and the rate of growth of meristem tissues is faster than the rate of tissue invasion of viruses (Note: Doing this is also not very easy as you need to use only the very very very apical cells of the meristem, and probably will need to do it a couple of times to achieve the desired result)

From what I understand, the success of this method depends on the virus. A lot of success has been had when removing CyMV from Cyms. I've read that OSRV can be much harder eradicate though.

[Ray]

Thanks for the clarification, Andrew!

I only think of clones in the orchid world, where the meristem is usually the key. Better broaden my horizons!

[kavanaru]

Originally Posted by Andrew

From what I understand, the success of this method depends on the virus. A lot of success has been had when removing CyMV from Cyms. I've read that OSRV can be much harder eradicate though.

Indeed, some viruses are easier to eradicate than others. It depends on their specific rate of infection of new cells. My personal experience was eradicating viruses from Rice, Sugarcane and Tobacco plants. You do not always have success (some strains more than for others) and it is important to work very precisely and clean to avoid contamination of the meristem... That's why I noted that "when done correctly"... it is hard work, but sometimes really needed... I can understand that large commercial cloning do not put much attention on this, and if they have a plant infected, when they clone it, they "keep" the virus in the new plants...