My peloric NoID

[The Mutant]

Thank you. I'm glad I knew enough about Phalaenopsis at that time to realize that what I saw on the shelf was not an ordinary one. This local supermarket does actually care for their flowers pretty well, even though the Phals are never any other than the mass-produced hybrids, they usually all look very healthy.

[camille1585]

I am not surprised that a keiki would bloom normal. Like explained in the link you provide, plant tissues are divided into 3 distinct layers. L1: the epidermis, L2: the subcuticular tissues, and L3: the 'core' part of the stem and plant, also comprising the meristem tissue.

After that, my knowledge is a bit rusty, I learned this years ago, so I may be wrong. Flower color and shape genes are in L1 and also L2. So if you have an incomplete mutation, called periclinal (only in one layer as opposed to all of them), the keikis originating from L3 will not carry the mutation! If the mutation is total, then the keiki should be peloric.

Where I'm lost is why does a meristem that grows the spike have the mutation, and not the axillary meristems? If you take the example of the plant called Mother in Law's Tongue (Sansevieria trifasciata), it seems possible. The leaves are green with a cream margin. The plant is chimeric, i.e the green and cream tissues are genetically distinct. I think it also has to do with cell layers. If you divide the plant, any new growth from the base will be green+cream. However if you take a leaf cutting, the new growth will be only green!