I have a Phrag. Appalachian Sunset, Eric Young 4N x Caricinum 4N.
In researching I found that Appalachian Sunset is comprised of 50%Caricinum, 25% Bessae, and 25% Longiflorum. So what does 4N indicate?

Thanks.

it indicates the number of chromosones. most plants are diploid (2n) with the normal number of chromosones (i don't know how many). 4n means it's a tetraploid with double the chromosones of the normal plant. it can be induced by various chemicals and sometimes occurs naturally. it often leads to bigger flowers than a 2n...

I recently wrote an entry on my blog entitled "What is ploidy?".

You can check it out here:

www.slipperorchidblog.com

It is the January 1st (and still current) post.

it indicates the number of chromosones. most plants are diploid (2n) with the normal number of chromosones (i don't know how many). 4n means it's a tetraploid with double the chromosones of the normal plant. it can be induced by various chemicals and sometimes occurs naturally. it often leads to bigger flowers than a 2n...

I agree!!:iagree: Colchicine is one of the chemicals used comes from the Autumn crocus plant.

Ramon:D

Are there any potential drawbacks to inducing 4N plants?

some of the chemicals used are very dangerous...

...... The idea is the age-old “more is better.” In other words, if you increase the number of genes that determine, say, size or color intensity, the better the flower will turn out.

Does it work?

That’s a subject for another post!

So where is the other post? I'd sure like to know!

Great article, D.H. Thank you very much

Hi Helga,

The short answer to "does it work?" is yes. As I mentioned, it's the more-is-better principle applied to genetics. Many genes have the equivalent of a volume dial, and the level can be turned up or down (depending on what the cell wants to do). Induction of increased ploidy does something similar, but it does it across the board.

Here's a way of looking at it:

Imagine you are looking for a new flat screen TV at Best Buy or someplace like that. Imagine also that on one wall there are 50 TVs. Now imagine that each TV is set to a different channel, and set to a different volume. Let's say the Simpsons is playing on one of the TVs.

Now, let's increase the "ploidy" of the TV showroom by DUPLICATING the wall of TVs with the same shows and same volume. Now there are 100 TVs, and 50 shows playing.

What you have now is a double dose of each show on each TV. You've got twice as much Simpsons blaring out as you had previously.

A similar thing happens when you increase ploidy -- you increase the number of genes and what the genes make (called the "gene product" which is usually a protein).

So if you increased the number of genes involved in making red pigments by increasing the number of chromosomes, you are that much more likely to have redder flowers.

In real life it's more complicated, of course, but hopefully this gives you a framework to think about ploidy.

Hope that helps!

Thanks for the analogy DH; it's really helpful.

What an excellent description. Took me a minute to put the picture (no pun intended) together, but now I get it.

thanks!

min

Very informative thread and I learned something new today!:hyper:

If you're not already a teacher, DH, you should be! Thank you very much for the explanation. Lets hope there is lots of 'red' in my Appalachian Sunset. It's in bud right now.

Helga.

D.H. if you are not already a Teacher, you should be. Thank you for your discriptive Explanation.
Helga.

One of the major reasons for creating 4n versions of phrags and paphs is that chromosome numbers differ between the species of different groups within each of these genera. This difference in chromosome number has resulted in a great deal of infertility in hybrids. By increasing the number of chomosomes to 4 pairs of each specific chromosome (2 pairs in pollen or ovule) it is possible to reconstitute some fertility in hybrids allowing further hybridization and development of specific lines. In genera like Phalaenopsis almost all species have the same number of chromosomes so the reasons for developing 4n lines is primarily larger size, more substance and more intense color.
Dean