Re: HYB: Louisa's Song/umbrata

Vertical slices through the petal show three basic layers--two epidermal
(outside and inside) and a central layer of parenchemal cells which give the
flower its stiffness, form, and petal expanse, including ruffling I would
expect.

It does not require an additional layer of cells to get plicata or luminata
pigment distributions.

Some set of external factors to the basic pigment sequence for
Delphinidin/Violanin probably set the pattern by establishing where in the
petal and which cells do not complete the synthesis of the pigment.

I emphasize "probably" as to my knowledge the rather complex experiments and
chromotomographic analyses of pigmented vs. unpigmented cells of  the flowers
in which the pattern the various pl alleles place the pattern have never been
attempted.  But I suspect "plicata" and all the rest of the series is
actually, speaking genetically, determined by where the pigment is *not*
expressed, not by where it is.

The tools appear to exist to follow this sequence all the way from DNA
sequence(s) to expressed pigments, but the process of doing so requires
megabucks and lots of concentrated, careful work.  As there is no economic
incentive for anyone to do so, it hasn't and possibly won't ever be done.

Likewise with the kind of pattern of LOUISA'S SONG.  Some factor(s) in the DNA
sequence set in motion through a series of intermediary steps the synthesis of
dark pigment(s) or more of the pigment (?) present in all of the fall except
the "Corona," if present.  An extra layer of pigment-bearing cells would not
necessarily be required--just like in the plicata allelic forms.

I do know, however, where reduplication of the epidermis has affected color of
fruit--in apples.  The old original DELICIOUS variety, which was colored about
like ROYAL GALA, usually marked "Gala" in the supermarket.  Through several
"generations" of bud sports appearing in orchards, Delicious has gradually
progressed to the deep, almost black, red of what is now offered in
Supermarkets.  They don't taste nearly as good as the old original, but they
sure look "Extra Fancy" and bring rather high prices.

The same thing has happened to ROME BEAUTY.  The old original was colored much
like ROYAL GALA as well.  The deep red modern sorts, most of them derived from
the "Law Strain," have a surface skin, just like the modern RED DELICIOUS of
various strains that is so tough it takes strong teeth to bite through, and is
unpleasant, in my notion.

The color in these two sequences of "improvements" was the result of
reduplication and re-re-duplication, I have no idea how many times, so that
the red anthocyanin producing cells are in multiple layers, coloring the apple
in solid red color. My source for that bit of information was Dr. Lief Verner
from the University of Idaho.  The apple IDA RED, grown widely in New York, I
have been told, was a seedling from a cross he made.

I lived through these changes, generation by generation, as I was born into a
western Idaho orchard-growing family, and ended up the principal stockholder
and Operator/Manager of the whole shebang.  Those activities, as I gradually
was given more and more of the responsibility for the daily operations and
record keeping for the orchards, sure did interfere with my iris
hybridizing.....but circumstances finally intervened and it became possible to
pursue another driving impulse and interest...which made dropping out of the
AIS a necessity, ending my status as a Garden Judge

Retirement has allowed me once again to get involved--thanks mainly to Keith
Keppel..

Neil Mogensen   z 7 western NC mountains

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