Re: Re; HYB: rebloom genetics
iris@hort.net
  • Subject: Re: Re; HYB: rebloom genetics
  • From: R* P* <r*@embarqmail.com>
  • Date: Fri, 14 Jan 2011 16:18:31 -0500 (EST)
Chuck: I have not seen all of this thread, but I think you are refering to the petunia study where two dark colored petunias where crossed trying to get a very dark to black petunia and the result was white. The explanation was that in trying to produce too much of the color the cells thought this was a virus or some malignancy and in defense they shut down the pathway altogether.
 
----- Original Message -----
From: "Chuck Chapman" <irischapman@aim.com>
To: iris@hort.net
Sent: Friday, January 14, 2011 3:48:25 PM
Subject: [iris] Re; HYB: rebloom genetics

 The petunia article has an explination of its effect. But can't recall it
right now. It is a very famous study, and is posted on several websites. I
have a copy buried somewhere on my computer. I'll need to look it up.

Another example is the effects of glaciata and luminata genes on each other.?
There will be sceptics and? potestors here. So be it. Much thought has gone
into this.

Consider? plicata locus with only luminata genes and? glaciata genes. No
regular plicata genes.

Now Luminata phenotype, as we know it is? a? mixed gene? or hyterozygous
condition. Long assumed to be a? genotype. It is? a mix of glaciata genes and
luminanta genes.?? Luminata X luminata? usually gives some glaciata (not
always) seedlings. Mostly it is a genotype? consisting of three glaciata genes
and one luminata gene.? Sometimes it is? two of each.? Now it has been asumed
that? the luminata gene is putting anthocyanin into central part of petal,
between the veins.? But my perception is that? it is increasing dosages of
glaciata gene pushing? anthocyanin away from? the veins. A reverse
perception.(Such as, is a zebra black with white stripes or white with black
stripes)? Glaciata and luminanta are? partially dominant to each other. Three
luminata and one glaciata gene is the zonal plicata factor. Adding each
glaciata gene pushes more anthocyanin out. At three dosages of? glaciata we
have typical phenotype? "luminanta" pattern.

Having said that , the question? that remains, "What does a flower look like
that has four sets of luminata genes?"? I'm not the only one looking at this
and thinking this way. Ther are now a few others looking.

I noticed some of my posts have the "?" in them.? I use "US" keyboard here.
Computer offers me "Canadian " keyboard as an option, but that does very wierd
stuff. But? if a computer is trying to translate my message as having a
"Canadian" keyboard, as I'm in Canada, then the wierd? stuff creeps back in.
Nothing I can do from this end. Perhaps something can be done at archive
level.

The dormancy gene seems to be a recessive. Growth factors need to be turned?
off. In absence of dormancy (or deciduous gene as some call it)? leaves
continue to grow, as weather permits.

The "vernalization needed" gene is a recessive, that turns off flowering
signal, or put anopther way, inhibits flowering.? When not homozygous,? the
"stop flowering"?? signal is turned off. So now flowering can proceed.

The "Stop flowering " signal? can only work? if in a homozygous condition.
That is all genes are? the same, or similar enought (various vernalization
alleles that will work together) .

For more detalis look up "MADS-Box genes and flowering"? on the web.? Warning,
it is a hard go, and will need several re-reads. But if you are looking fo?
the complex answers, they are found there.

Here is one link to look at.


http://www.ndsu.edu/pubweb/~mcclean/plsc731/flower/flower7.htm

Chuck Chapman


-----Original Message-----
From: Linda Mann &lt;lmann@lock-net.com&gt;
To: iris@hort.net
Sent: Fri, Jan 14, 2011 1:21 pm
Subject: [iris] Re; HYB: rebloom genetics

   Re: multiple dosage of dominant genes?
?
 The examples (in irises) that I could think of where multiple doses of
dominant genes do something different (i.e., I(s)) than a single dose  (and
the one you mention for Petunia?) would effect different stages of
development of particular cells in a flower - i.e., the cells that
differentiate to form the rims vs those that develop the center of the  petal
etc.?
?
 I haven't been able to understand how that could work - it's almost as  if
one copy of the gene does one thing (inhibits or induces pigment  chemical
changes while those particular cells are forming) while the  other copy
"rests', then when it's finished, & some other cells are  developing & forming
pigments, the other copy starts working.?
?
 Or if all those petal cells are at the same (temporal) stage of  development
and the genes are activated simultaneously, how are  different cells affected
by the "same" gene??
?
 So what I was wondering about is how the multiple doses of cycle  dominants
would work and what that could do, which cells are affected,  and at what
stage of development.  Plus I confess I still get a little  mixed up about the
various mechanisms that are being turned off and on  by the genes you are
proposing as dominant vs recessive (not to mention  the ones you aren't as
sure about yet) - plus all the question marks  that are showing up in your
archived posts lately make it a little  harder to figure out what you are
saying.  I need a visualization of it  all.  Schematic.  Any engineers/system
modelers out there want to try to  make one to post??
?
 The power went off for a couple of hours right in the middle of this  message
composition, so I lost whatever other train of thought there  might have been
;-)?
?
 Linda Mann east TN USA zone 7?
 31oF and climbing, with SUN, and NO snow showers!  Hoping "they" are  wrong
about freezing rain/sleet coming soon.?
?
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