Perhaps cold weather could cause the ring of satsuma cells in the Cambium layer to die off? ... Next perhaps the Trifoliate cells took over. Vienna, Austria, is fairly cold as I understand.
It's interesting to me. I wonder if it is possible to Intentionally create a chimera. I read that most garden Chimeras are from buds that form across Graft unions. Poncirus is a deciduous cold tolerant species, and is seems to be able to infer some of it's tolerance to the Satsuma cells allowing them to survive in cooler weather. So why not some other combinations?
Wow Sylvain; (interesting read) My knowledge of Cambium layers was based on grafting manuals from the 1900's. Outdated thinking. (But the grafts still work!)
I would suspect you are correct with the SSP layers at the growing tip. After all the woody structure seems to take after Poncirus Trifoliata var: Flying Dragon. Prague has the twisted flying dragon form. Now if someone could replicate the chimera with Citrange & XieShan Satsuma to get a more upright form...
Concerning regular crops of Prague - After formatting enough in number fruitlets (0,5 to 1 cm) I remove constantly every new flower (in May, June) Last year in pot there were 15 fruits: Now after I transplanted the plant in the ground in April - it is stressed, it has 7 fruits. The base is Swingle citrumelo.
Zap, what you say has no understandable meaning because meristem has 3 layers, not 2. We already found the four possibilities: MMM (mandarin), MMP (the prague), MPP (poncirus with glossy fruits) and PPP (poncirus). The other possibilities are very unlikely to be seen one day because they would involve cells skipping a layer.
M is for mandarine. I don't use satsuma because it has to be proved. P is for Poncirus. The first layer is on the left.