Genetics 101

[Bikerdoc5968]

While I'm new at this orchid thing, I am finding orchid genetics somewhat mind-boggling. I have some educational background for understanding this stuff, but must be brain-dead regarding orchids...is it all simple Mendelian genetics....autosomal dominant/recessive...sex linked??????? I have five (couldn't upload all) orchids I recently aquired all named Dtps Leopard Prince 'K H' x Dtps Chain Xen Pearl 'BS'. They are from, what I believe, a reputable grower in Florida. They all look "major" different! Is this given to seed crossing and just what happens, i.e., some show dominant traits while others show recessive traits? If this is the case, then I guess orchids are just like human variation...so I guess there are lots of Tom's, Dick's and Jane's out there in the orchid population. So if anyone is willing to educate me more or at least make reference to reading material....thanks... just keep it simple. Remember, I'm brain-dead!

[catfan]

Seedlings can show a great variety of forms and color combinations. Plants that are cloned should all be relatively the same.

[smartie2000]

harlequin patterns are recessive traits I believe. However I think it is much more complex than the chi square
I see that only the first one is a true harlequin. The last one has a few spots
The second one looks a lot like what one should expect from leopard prince.
These guys can vary a lot....the have been hybridized and selfed and sibbling crossed so many times (sometimes we don't know what the parents are like anymore). I have had people ask me what they will expect from their seedlings and I just give suggestions of the best possible outcome if they are lucky, not that I am a phal expert at the moment. And they are way more complex than a slipper orchid
Buy a flask or compot if you really want a winning plant
Apparently two harlequins bred together will give more harlequin offspring. Other crosses with a harlequin just give a 25% chance

where is the member that breeds phals....? I haven't heard from him for a while

[pavel]

A short version:

Even in humans, there are many physical traits that are not simple dominant/recessive. Some genes exhibit codominance meaning if both are present, both influence that trait but each adding its own "spin" on things. Some physical traits are not the result of a single pair of genes but rather several pairs. The more pairs involved, the more unpredictable the outcome of a cross [because you now have that many more possible combinations that could be created]. Add to this that during gamete [sperm/ovum] formation, mutations like genes from one chromosome crossing over to become part of a different chromosome can occur and you've just made matters even more complex. And just to really make your head spin, remember too that unlike animals, many plants are polyploidal -- that is they have more than the "normal" two sets of chromosomes. In humans having even just one extra chromosome is generally lethal to a developing embryo. In the few cases in which it isn't, such a state has severe consequences like Down's Syndrome ... the result of just one extra chromosome #21. Plants, however, often don't seem to suffer and may even demonstrate improved vigor as a result of having extra chromosomes.

[IdahoOrchid]

When you get back to the "pure" species it is a lot closer to what you expect, but there is still quite a bit of variability.

With these it is like Smartie has explained.

[Piper]

Wow, Pavel...and I thought you were merely an expert on reptilian bums!

McImpressed