Meristem is just the same plant....4rd, 5th etc meristem is the same, full identical with mother plant, same as a division....the problem is with meristem is oldering...telomers renew at fertilisation, but don t in meristems or divisions....weird, but if you make a meristem from an 100 years old plant, tiny plants from that are also 100 years old, genetically...
Waldor just re-meristemed George King ‘Serendipity’ from their original plant because they noticed a decrease in quality in those meristems out there from others. Quality of meristems does seem to diminish over future generations. And just because someone has the OP and has meristemed it, it might be they are selling meristems done by someone else because theirs’ sold out long ago.
Toshie Aoki ‘Pizzaz’ was meristemed to death (meristem of meristem of meristem…) and most meristems today show tremendous variation from OP. There are no known OP of this still available. Carter and Holmes offered a division of their early meristem a couple of years ago. I grabbed it. C&H’s is the one that’s like the OP that they’ve used for breeding (crossing) for years. It looks like the original Toshie in their photo. I have had 3 or 4 ‘Pizzaz’ that were awful. Two from Akatsuka and one from Plato Matthews. Two were virused, maybe some was cultural but very muddy colors, not clear yellow with red flares. Terryros and I are growing one separately to see how much culture affects them.
One other factor is how many meristems are taken at once. Frank Smith told me they never do more than 300 at a time as quality decreases.
This is way out of my wheelhouse, as I can’t even tell you what a telomere is, and I’m sure some of you who are more scientifically minded can critique my statements. But I know from multiple breeders, there are meristems not as good, as good or better than the OP. Is that because they were taken or not taken from OP? I don’t know.
But one example of ‘better than’ is Pamela Hetherington ‘Coronation’. Dave Off (this is his favorite Catt) says the meristem is better than the original, in his opinion. I have the original from him and the meristem from him. When I saw the meristem for the first time it really got my attention. The meristem is a much stronger plant and better flower from the blooms I’ve seen, so I agree. This is all empirical/anecdotal, but… Genes do interesting things. Think natural (4N), as an example.
George King ‘Southern Cross’ came from a meristeming of ‘Serendipity’ by someone in Australia, if I remember correctly that Carter & Holmes got.
We have identical twins. Genetically identical on the genetic testing to the point each of their children show to be the children of both twins. However, the twins have different genetic variants. It does not appear anything in this universe is identical, not even identical twins where the egg divided.
Having said that, your point about a meristem taken from a 100 year old OP, is indeed that same 100 year old plant (but perhaps with variants??). But a division of that original 100 year old plant would be that exact plant genetically.
