Very rarely, if ever, will a 3N X 3N produce any off spring. In orchid
breeding I have learned to never say never. Instead, 3N are most often
crossed with 2N with the hope that the 3N will produce a few unreduced
gametes (6N pollen or ovule). This type of cross is in fact looking for a 6N
X 2N (or 2N X 6N) mating producing 4N offspring. When flasking a crossing
like this, you hope for a couple of viable plants out of a pod. In my
experience, most times the cross will not take . . . but it could happen.

Most 4N Phrags can be traced back to the Eric Young Foundation. The
foundation converted 2N besseae (and other phrag species) to 4N using
colchicine. The various 4N phrags were then crossed to produce some
stunning 4N hybrids. The Foundation sold a lot of 4N besseae hybrid flasks
a while back (Baltimore EOC timeframe). We are now seeing what came out of
those flasks as well as the next generation of hybrids on the market. They
seem to plentiful, inexpensive, and very high quality this year.

Pat




"Xi Wang" wrote in message
news:Ujt0e.767329$6l.713106@pd7tw2no...
Ploidy refers to how many sets of chromosomes a cell nucleus contains.
Usually, every cell has two copies of a chromosome, and is designated 2N.
Usually, higher ploidy number means more robust plant (sequoiae are 6N and
are huge trees, and some of the most robust)- if some genes get damaged,
they have more backup genes to work with. However, a 3N plant can only
produce progeny with a 3N plant, and 4N plants, preferably with other 4N
plants.

Cheers,
Xi

wrote:
I've most recently seen it (4N) on a phragmipedium given to me. Thank
you.