Ok, I just found what's probably the best resource on phyllotaxy I found so far, especially when including the references at the bottom
Phyllotaxis: In Search of the Golden Angle
http://www.sciencedirect.com/science/article/pii/S0960982211006415
Excerpt:
"
The regularity of the arrangement of leaves, flowers or floral organs in plants, a phenomenon called phyllotaxis, can not only be easily observed by anyone, but it is also the source of inspiration for scientists since the classical antiquity. [...] For instance, if leaves grow one by one, each at a constant angle from the previous one, the phyllotaxis is called distichous when the angle is 180° or spiral when the divergence angle is close to the golden angle, about 137.5°. When two evenly spread organs are formed on a node, the phyllotaxis is decussate, and whorled when three or more organs arise simultaneously. Although phyllotactic patterns tend to be stable, they are affected by environmental factors and may change during the development of the plant. For instance, in the model plant Arabidopsis thaliana, the embryonic leaves and the two first vegetative leaves show a decussate pattern before switching to a spiral phyllotaxis for later vegetative leaves and flowers, and finally to a whorled pattern for floral organs"
Mine go from decussate (regular opposite) to whorled (3 leaves on same level), then switch to spiral (because they start alternating) and then revert to whorled when the internodes shortened at the end of the transition to flowering, and spiral again in the buds.
It's the first transition that matters, the rest is then inevitable.
"
genes of the PLETHORA family have been shown to modulate these transitions by fine-tuning the mechanisms of polar transport of auxin, a key effector of organogenesis."
Further research shows the PLT1 and PL2 genes are responsible.
"The response to auxin signals may be mediated, at least in part, by the
PLETHORA genes:
PLT1 and
PLT2."
The same genes are also responsible for root development. This raises two questions, can I spot the tris faster by looking at roots, and do the plethora family of genes follow mendels simple rules of inheritance.
I also ran into something called expansin, which combines with phyllotaxy leads to a load of additional info to go through. Theoretically it may be possible to create tri-whorled in a bottle...
The
book The Molecular Life of Plants talk about what I mentioned in an earlier post, that the different than usual phyllotaxy is caused by a different interaction of cytokinin and auxin, as has been shows in a mutated gene in a maize variery that encodes a cytokinin signal transduction protein.
Possible influence of sulfur availability:
"Low sulfate levels also downregulate the genes involved in auxin biosynthesis and transport, and elevate the accumulation of PLT1 and PLT2. This study suggests that sulfate level affects the primary root elongation by regulating the endogenous auxin level and root stem cell niche maintenance."
Plastochron
The difference between the whorled and semi whorled/spiral may be all due to a plastochron difference. Cool word, plastochron, like a super villain. Plastochron is the time between leaf initiation. Plastochron is however regulated by different genes than phyllotaxy. I've had whorlers with a non-optimal plastochron as in one of the three starting a little later.
I did top it, which I believe was suggested it wouldn’t continue. Don’t know if it was the topping or it would just grow out of it. I originally was going to pollen chuck it, but after researching didn’t bother.
