Any alba forms of NF?
 

I have an Ascofinetia Apple Blossom, which according to the label is bred with Asctm ampullaceum 'alba'. The flowers on this plant are pink.

Since alba forms are recessive, this indicates that the white (but non-alba) NF dominated the recessive white in the Asctm ampullaceum, bringing back the color.

For breeding purposes, does anyone know of a an alba NF?
Perhaps we should look among the plants with green root tips?

White flowers can be caused by several different mechanisms. A normal gene product in a white NF can offset an abnormal gene in an alba Ascocentrum.

I'm wondering if you might be better served with a green "Hisui".

I'm not certain myself, but I think your best bet is to try a variety that has absolutely no anthocyanin pigmentation anywhere in the plant. While green root tips as you mention is a start, it should also show no pigmentation at the bottom of the main stem or in the peduncles.

Kogane-nishiki I think is one of the best candidates

Labels are often deceiving. There are also many mislabeled plants.

True.

However, this plant comes from one of the well known producers in Hawaii, so I have a fair level of confidence in the label.

And, I know the Cherry Blossom well. There is no doubt, that plant is labelled correctly.

The key is, how do we identify a genetic alba in a population of white flowers?

I'm with Hakumin on this one. No anthocyanin anywhere. I have Aojiku Fugaku that differs from the standard Fugaku in having a green stem. Mine doesn't have root tips at the moment but IIRC they are green. There are a number of Aojiku variants out there and these are possibilities.

BTW, NWO lists Kongane-nishiki as having mud brown roots, (I also thought these were green), so maybe there can be some variation within these cultivars to watch out for.

Another plant is Jitsugetsukou, a white tiger type that has white blotches along the leaves. It has very pale green, almost white, roots and a green stem, but doesn't flower that readily (or at least mine doesn't). Just have a hunch that this one might carry an odd mutation that might not be homologous (or line up) with alba ?

I think Orihime might be another candidate, the stems are green, peduncles green, and root tips green, however in some neo varieties the pigmention in the stem only shows up at the base in really mature growths. My Orihime is a keen flowerer and has decent flowers. You could contact NWO, I know Glen was selling some Orihime seedlings a few years back and chances are that some of them don't carry variegation and these might be available cheaper (if he hasn't binned them).

A really different one to experiment with would be Senzai, the mini bean leaf. Mine has green root tips and a green axis, but I've not yet managed to get it to flower and apparently it is a bit iffy about flowering. However, if the dwarfism was passed on, at least in part, to the hybrid it would potentially make for an interesting one. If mine ever flowers, I will try some of it's pollen on one of my broad leafed variegated types like Kinkounishiki or Takaranishiki because even if the variegation pick up is improbable at least I'd get some idea about the dwarfism genetics.

Koganenishiki should not have mud brown roots. It's greenish-yellow root tips are a celebrated and essential characteristic for the variety, and part of the official definition of the variety.

NWO listing it as mud root is incorrect.

Thanks for the clearing this up.