If you cross a 4N with a regular the offspring would become 3N. Right?

If you cross a 3N with a regular the offspring would become 2N. Right?

This way or could a cross 4N x regular become a regular?

I'm a little confused about this diploid=(2N), triploid=(3N) and tetraploid=(4N) things!

I not a scientist but this is pretty easy to nail down. There are, of course, exceptions.

If you mean "regular" to be the normal state or 2N (diploid) then here are the rules:

4N x 2N = 3N (triploid and normally sterile). Sometimes 3N plants will breed.

3N x 2N = normally not possible due to sterility issues. There are some possibilities of polyploidy in such a cross, but it would be a genetic mess.

4N x 2N is never 2N, always 3N

Our in house botanists will probably disassemble all of this, but in lay terms it works.

Very useful info!

Very useful info!

:iagree::iagree:

Bill's answer is right on. The way he lays it out is pretty much what happens in paphs and frags. 3n plants should probably never be used for breeding. In phals it gets worse because many 3n plants will breed as pod parents and someone always tries it. The progeny are usually aneuploid (uneven chromosome count) and frequently sterile. Rarely, a 3n plant when crossed with a 2n will produce 4n progeny. This is the case with one famous breeding plant that is 3n, P. Golden Sands 'Canary'.
Dean

Kanab, Utah! As in "where the hell is Kanab?" t-shirts?? I have one.

You must have been a long way from home!!!! Kanab is 25 miles east of Zion National Park, 30 miles south of Bryce Canyon, 55 miles west of Lake Powell and 70 miles north of the Grand Canyon. Nice place to live but isolated and no other orchid growers near.
Dean

Must be the same one, went to all of those parks while we were out there. Beautiful area out. :D