I know how complex it can get. I was trying to understand all the hybridization and the chromosomal numbers and I gave up. Plants seem to be quite tolerant of vast variations in chr. numbers. Quite frankly animals seeem to be less tolerant and humans even lesser. I think in humans , even slight changes in DNA will result in aborting further development. But ,of course, rare instances of extra chromosome is tolerated ( Down's syndrome) where Chr15 or Chr21 or both could be replicated.
Colchicine , though quite poisonous , is used to treat extreme gouts and is very effective in reducing inflammation. It makes sense in what you said about it being used in orchid hybrids. Its use is not very common since it, though not classified as DNA altering drug, has caused 'mutations' in blood cells (leukaemia).
It is interesting that plants and animals have many things in common
Thanks for the info, Orchidflowerchild.