HYB: Pink Inhibitor (was pink sdlgs from Photos)

Adam, you may be misunderstanding what inhibitor is being talked about.

The "I" gene, or dominant inhibitor (see TWOI, p. 397ff, where this situation
is symbolized as "RA," for "reduced anthocyanin") is a factor that
more-or-less disrupts or prevents the last step in anthocyanin synthesis
before "Delphinidin" (the parent compound in iris blue) is reached in the
synthesis sequence.  The pigment remains in the flower in a transparent or
white form, known as "Leucodelphinidin."

The inhibitor is on the blue side of the fence, not the pink.  It has no
direct effect on the pink at all.

What it does do, in reference to pinks, is to allow "pink" as such (as in
VANITY, HAPPENSTANCE, or countless other modern pinks) to be seen as pink
instead of pink with violet.

Pink with blue or violet gives the flower a color like that in the historic
MARY RANDALL, or the current VIENNA WALTZ .  In these varieties *both*
Lycopene pink (oil-soluble) and Delphinin mauve-blue (water-soluble)  is
present in visible form.

There are two main, separate and distinct pigment families--one is the
Carotinoids, among which is Lycopene, the pigment in "pink," and the other is
the Anthocyanins, among which is Delphinin ("Violanin" in some texts), the
pigment in violet and blue in bearded irises.

These two families are different in solubility, differently synthesized, and
differently located within the petal.  Both, either or neither may be present,
with all sorts of variation in color of the two types making possible the
"rainbow" range of color in irises.

With this in mind, a re-reading of Sharon McAllister's post will probably
bring her comment to mean something different from what you may have
understood there previously.

This whole matter of pigment and pattern in modern irises can get terribly
confusing.  It is difficult to grasp because we cannot easily see what really
goes on inside the cells where pigments are located without complex and
technical equipment.

What we *can* see with the bare eye or even a 20-power magnifying glass
doesn't make the pigment distinction visible.

What we experience is a combination of two remarkably different ways colors
can mix, resulting in an array of hues and tints or tones that amaze the mind
and delight the eye.

Where an understanding of the pigments, how they are inherited--and sometimes
blocked--becomes useful is in trying to understand what the heck is happening
in the seedling patch.  The reaction, "Where did *that* come from?" is a
familiar question to all who have raised more than a few seedlings.  After
that, genetics and pigments may become rather fun.

Neil Mogensen  z 7  Reg 4  western NC mountains

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