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HYB: Chuck's yellow plicata rant

Chuck, I hope you don't mind, but I decided to re-post your "rant" about
yellow plicata here on iris talk with a subject line I can find again
when I want to go back and re-read in the future.

<                   You do have yellow , pink, blue etc amoenas even if
the carotenoid and
                   anthocyanin pigments are controlled by separate genes
and a yellow amoena
                   will not afect the distribution of the anthocyanin
pigment. Look at the two
                   attached pictures of a chimera of Summer camp. The
exact same distribution of
                   the anthocyanin and the carotene pigments are obvious
when the anthocyanin is
                   removed. the original idea was that plicatas are a
pattern of the anthocyanin
                   and that thus you couldn't have carotenoid plicatas
as the plicata gene
                   didn't control the cartenoid pigments. A lot of the
original "yellow
                   plicatas" were a plicata pattern of anthocyanin on a
yellow ground. This
                   basically was called a misuse of the term and I agree
fully with this. Thus
                   the terminology was very incorrect used this was and
we now call these
                   plicata on a yellow ground. Now when people say
yellow plicata they refer to
                   a stitching of yellow  in a plicata pattern on a
white ground. When Light
                   Beam (Blyth 1985) was first introduced Barry called
it a yellow plicata. It
                   was from Broadway X Beverly Sills. He got called to
task for using such a
                   term. Broadway is a plicata with intense , unmarked
yellow standards and
                   falls with red plicata markings around the falls
which are white in the
                   centre. A close look shows that there basically is a
yellow rim around the
                   standards and the anthocyanin is on top of this, not
what I would call a red
                   on white plicata but a plicata on a Joyce Terry
ground. Beverly Sills is a
                   pink but it and its parent Vanity throw lots of
plicatas. Either one or both
                   could be a plicata with the anthocyanin removed by
one of the anthocyanin
                   removal genes (recessive or dominant) and with BS I
suspect "I". I used LB in
                   a plicata cross and got all plicata offspring. Barry
also has done this and
                   has gotten the same result. Jean Witt had written an
article (I'd have to
                   look up the reference) where she was a heretic (my
term) and presented an
                   argument for there being yellow plicatas with the
yellow pigment distributed
                   in a plicata pattern just like the  anthocyanin is.
                   In the cross of mine with light beam I got some
seedlings with a purple
                   plicata stitching on a Joyce terry pattern. The
colour of the stitching is
                   red when it is on the yellow ground and violet-blue
where it is on the white
                   ground on the falls. There also was one seedling with
yellow stitching in
                   exactly the same pattern as in a plicata. Dots and
veins and not solid as in
                   a JT pattern.

                   Facts are facts, theories try to explain facts, if
they don't then we need
                   another explanation. I have accepted these facts to
mean that we can have
                   carotenoid pigment distributed exactly like
anthocyanin apparently controlled
                   by the same factor. You don't check out something
that you don't believe in
                   its existence so this hasn't been researched as it
doesnbt exist, right?
                   Well my first thoughts were that perhaps the yellow
was a flavanoid so I
                   checked this out. That is not the case, it really is
an oil based yellow
                   pigment, not water based. Currently I'm trying to
find out if we can call on
                   a structural explanation. That is a difference in the
cell structure  that
                   somehow prevents any pigment from being present. It
seems to be related to
                   the original genes from Iris variegata where we can
and do have both water
                   based and oil based pigments distributed exactly the
same way, 100 percent
                   matching. You can't have this if one gene controls
yellow and one controls
                   violet, there is no way then can be aligned this
precisely. With all the
                   evidence supporting  I. variegata as being one of the
ancestor species  of
                   the plicata pattern  there does seem to be a
                   I present a program  I call "Pigments and Pattern"
exploring and explaining
                   how we put all the various gene controls and pigments
togther to make the
                   various iris flowers we have. I always trot out my
data on "Yellow plicatas"
                   It appears to be quite convincing.
                   Once there is a general (or increased )
acknowledgement of its existence then
                   there be research into how it is so. Right now there
is a dearth of research.
                   After all why research something that doesn't exist.

                   Saying "By definition, a plicata must  contain
anthocyanin!" is an attempt
                   to define it out of existence.
                    I have heard various explanation that could possible
explain some
                   situations, but they don't really seem to be able to
explain all things,
                   especially  something like Time Warp where even if
there is some anthocyanin
                   there on top the yellow to make the dots stand out,
you can see that the
                   yellow is there in dots. I have taken several good
close ups of a number of
                   my yellow SDB  patterned from plicata genetics that
show dotted and streaked
                   yellow on white that even if there is some
anthocyanin there, it couldn't
                   possibly account for what is seen.

                   Sorry for the long rant but the more I study
Pigments and patterns the
                   more I realize that there are factors influencing
them that haven't been
                   fully explored. This is one, flavanoids are another
                   and there is Anthocyanin Enhancement ( anthocyaninic
vacuole inclusions) and
                   a couple more I suspect and have good documentation

                   I feel there is a lot of research that could be done
that is not being done.
                   Dr. Randolf did some nice genetic research with three
generation of crosses
                   with good data collected. This data is still
available in his book and only
                   recently have I been able to properly analysis it. We
need more research like
                   this. WE now have the tools needed. The digital
camera is an excellent tool.
                   Randolf's research involved other people making the
crosses and sending
                   seeds to him. He had to grow them as it needed an
expert to examine the
                   seedlings. We can now economically take photos of all
the seedlings and
                   examine at them at leisure. Seedling donbt have to
be grown by the person
                   doing the evaluation as good photos can provide lots
of useful   information
                   and be distributed to as many people who can all do
their own analysis in
                   their area of expertise.

                   Many of the crosses that can provide the data are
being made. It's just
                   necessary to collect the data that is there and get
it to those willing and
                   able to analysis it.

                   Enough ranting for now.

                   Chuck Chapman >

Linda Mann east Tennessee USA zone 7/8
East Tennessee Iris Society <http://www.korrnet.org/etis>
American Iris Society web site <http://www.irises.org>
talk archives: <http://www.hort.net/lists/iris-talk/>
photos archives: <http://www.hort.net/lists/iris-photos/>
online R&I <http://www.irisregister.com>

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