how do orchid genetics work?
 

I was just thinking that next year I might try to actually propagate orchids from seed. The first thing that came to mind is that I want to buy a Bl. Morning glory and cross it with my brassavola nodosa. But that wouldn't be much of a cross because morning glory is already made up of B. Nodosa with L. Purpurata.
So i was wondering what would the outcome be? And how diverse are the orchid genetics? If I did a cross like that. Would I get like a Bl. Day and night lady or something? Or could it be so diverse that I could get a simple genetic like a nodosa and a Purpurata by itself?
because when I think of genetics, the reptile hobbyist pay of me kicks in. If I need a bumblebee ball python to a pastel ball python I would get some pastels, super pastels, spiders, bumblebees, and killerbees.
(For those that don't know, a bumblebee ball python is a color and pattern mutation produced when breeding a spider to a pastel.) So breeding a pastel to a bumblebee could be broken down like (pastel x spider) x pastel. so you see you're getting a double dose of pastel to get some similar results of what you started with plus some more complex results like the killerbee.
I know this might be a lot and probably doesn't make too much sense, but I'm just trying to understand how orchids genetics really work. It'd be cool if it were similar.

Orchid genetics are much more complex than that. Some traits or colors are recessive. Color dominance can occur several different ways. In Cattleya alba forms are recessive; ditto in Paphs. However, white Paphs are the result of color suppression, which comes from niveum and one other species, but not the other two species in the Brachypetalum group.

You need to do a lot of reading, to get a good understanding of orchid genetics.

that exact cross has been done and is called Bc Wonder Star - I don't know if there are photos on the internet. I have seen photos on OrchidWiz. Its not that different to Morning Glory, at a glance.
Orchid genetics can be very complicated, especially with phals that have been extensively hybridised. I suggest you research ploidy of orchids as a starting point.

One article
A Brief Look at Polyploidy

Thanks for the link orchidsarefun. Just reading it got me really confused. How do breeders or cultivators (I'm not sure how you call someone that does the crosses) make their decisions then?
Like is there a way that they can look under a microscope and see the chromosome count and make a more direct and precise decision on what they want to do? Or did they just let curiosity take over and just wonder what would happen if this was crossed with that?
personally I'm leaning more toward the curiosity of things. Like I said hopefully next year I'll be able to do into seed propagation, and since buying the brassavola nodosa I've really really gotten into cattleya orchids. As my collection grows, my imagination just keeps on going.

I don't want to lump all breeders in one bucket as there are a range with different motives. Breeding for commercial production is a prime example. Species breeders have it fairly straight-forward as most species are 2N. However this is not a 100% given as ploidy can be chemically changed in flask using colchicine for example. Yep - people want to improve on the original species ! Thankfully chemical/colchicine use is not widespread.
Ploidy can be counted and its done using a new root section. Its time-consuming and thus costly and hardly anyone does it !
Here is a phal database, though not updated for a while:
Confirmed Ploidy Database | ORCHID VAULT
I haven't come across any other database.
The basic premise of hybridising is to produce something better than the parents, for example colour, number of blooms, size of plant etc. OrchidWiz is a useful programme to have as it enables you to see what has been produced in the past. You are then able to research potential parents and see if the parents have any registered progeny. Registered progeny = good breeder.
I am sure there are thousands of 'curiosity' breeders as there are a lot of orchid registrations that are one-offs. There are equally as many hybrids that no-one has ever heard of because they have not been placed into commercial production.