Iâ??m sending a photo of a pigment extraction of Thai Orange, with a
before and after photo of a fall. I may have to send this photo in a
separate response. When you look at the photo you will see that the
amount of lycopene is significant, probably as much as the darkest
lycopene pink iris. Not trace amounts, and significantly more then the
amount in apricot or peach flowers. My â??Kitchen chemistryâ?? methods are
not able to pick up on trace amounts as it is more of a tape measure
measurement, not a micrometer. I have found that the yellow in orange
flowers to be a recessive gene and completely independent of lycopene
and regular carotene inheritance. This is based on an analysis of many
crosses involving these pigments. We can get a yellow with red beard,
such as Throb (many other examples). These prove to be recessive in
breeding, and crossing with a pink will produce all pink seedlings as
long as there are none of relevant recessive genes present.
As the ya and t genes are on separate loci, and not alleles, the one
is not dominant or recessive to the other, but completely independent.
You will not have read anything about this in the literature for the
simple reason that I have not published anything yet. I will at some
point, but need to follow up with a few more test crosses so when I
publish I can describe its action in more detail. I have discussed
this alternative yellow gene here and on iris-talk, so you can look up
the information in the archives for more information and details.
I didnâ??t say Girl Pixie doesnâ??t have any ya genes, I said that if it
doesnâ??t have any ya genes that there would only be pink carotene
(lycopene) in any offspring of the cross you made. With the
alternative yellow, and tttt we have orange. With only one Ya gene we
then have pink flowers. (This is not considering the recessive
reduction of cartenoid gene which produces the white with red beard)
To say that there is an â??orangeâ?? gene because there are orange flowers
is the same as saying that there is a red gene because there are red
flowers, a purple gene as there are purple flowers, a brown gene as
there are brown flowers etc etc. All of these are wrong of course, so
evidence requires some genetic test results. What would you expect
from a cross of orange X pink without any of your theoretical â??oâ??
genes? I would expect all pink offspring, such as you got so far with
The AIS never chose the â??oâ?? symbol for the orange break. You are
referring to the book by Vallette, that was independently published,
not an AIS publication. There are lots of things published by AIS
members, that does not make them â??officialâ?? AIS position, even if they
are published as an article in the AIS Bulletin. If ther is any
official designation of gene it would be The World Of Iris, and there
is no discussion of orange genetics there.
There is an advantage to hybridizing as then you can observe results
yourself and collect data. I suggest you need to do some test crosses
with orange flowers to test out your ideas further. Theory does need
to be grounded in facts and observation. We do indeed have enough half
baked ideas that do not have experimental or scientific backing. That
is why I waited until I had some good evidence before discussing the
â??alternative yellowâ?? and why I will wait for some more test crosses
before publishing. I would like it if everyone was a carefull with
--- In firstname.lastname@example.org, "Dan Meckenstock" <dmeck@...> wrote:
> I am surprised at your comments since I am unaware of a double
> homozygous recessive genotype in the carotenoid pathway producing any
> color other than that of the first loci being blocked. I assume `t'
> precedes `ya' in your pathway and in which case the (tttt, ya ya ya
> ya) genotype would have a pink phenotype or lycopene would be the
> dominant color.
> If you are finding lycopene in an orange flower it is because not all
> of the lycopene is converted into beta-carotene which, when
> beta-carotene is the predominant carotenoid, makes the flower orange.
> Recall, lycopene is the substrate for beta-carotene. Thus, there will
> always be lycopene in orange and yellow flowers at trace levels.
> Also, if the orange genotype is (tttt, yayayaya) then what is the pink
> genotype? You say Girl Pixie doesn't have any ya genes, isn't that the
> same as saying the ya locus is homozygous recessive? As presented,
> your genetic explanation does not explain the difference between pink
> and orange.
> The best evidence I have right now that orange has its own gene is the
> simple fact that orange flowers exist. Also, Aitken and other authors
> in the AIS literature have stated orange is a recessive trait. Since,
> their claim is consistent with the carotenoid pathway as it is
> understood today, I agree with them.
> On another note, the AIS chose the symbol `o' for the orange break in
> 1961. I suggest you not make any changes to the nomenclature by adding
> ya until you can show how it relates to the pathway. There are already
> too many half baked ideas in iris genetics.
> --- In email@example.com, "irischap" <irischapman@> wrote:
> > This is indeed a nice photo of an snow resistant flower.
> > I do differ with you re interpreting the genetics of this. I view
> > Infanta as having four sets of the tangerine gene that is tttt.
> > As well as with all oranges it also has four sets of a recessive
> > yellow gene that seems to only be associated with the orange iris.
> > (research still pending) that I will call , for the time being
> > "alternate yellow", and label it ya, so that Infanta is tttt
> > To check this out further I would suggest that you either grind up an
> > Infanta petal in methyl alcohol and filter it. As lycopene is only
> > partially soluble in alcohol, the residue would show the typical
> > lycopene pink colour. An alternative would be to boil an intact petal
> > of Infanta in methyl alcohol, this will reveal the underlying
> > Thus Infanta X a pink, will produce all flowers with lycopene. If
> > Girl Pixie doesn't have any ya genes then all the seedlings will be
> > pink. Of course there are the anthocyanin genes in Infanta which,
> > depending on the mix of anthocyanin genes in Girl Pixie, will show in
> > various ways.
> > Thus when we have a cross of two orange iris, we have a cross of tttt
> > yayayaya X tttt yayayaya and thus all the offspring will be tttt
> > yayayaya and thus orange.
> > I have not seen any evidence that would convince me that there is a
> > seperate gene for orange, or that it is anything other then a mix of
> > yellow and lycopene.
> > Please feel free to send any information you have (evidence, not
> > theory) that there is a gene for orange, that can not be explained by
> > what I have outlined above.
> > Check the colour of the rest of the seedlings in this cross.
> > Chuck Chapman
> > --- In firstname.lastname@example.org, "Dan Meckenstock" <dmeck@> wrote:
> > >
> > > This special SDB ice pink is the product of years of breeding and,
> > of course, divine intervention. Last night while I was sleeping the
> > skies opened up and miraculously turned this early bird into an ice
> > pink. Note the exceptional cold tolerance of this seedling. If this is
> > not proof intelligent design then I do not know what is. I think I
> > will release this little miracle for use in Barrow Alaska--call it
> > PINK ICE CREAM.
> > >
> > >
> > >
> > > On a more serious note, this seedling is an F1 derived from the
> > cross (Infanta x Girl Pixie). Where Infanta is a light orange glaciata
> > and Girl Pixie is pink. We know from this F1 that the genotype of
> > Infanta is heterozygous TTtt, and homozygous oooo where T promotes the
> > conversion of lycopene into beta-carotene and 'o' blocks the
> > conversion of orange beta-carotene into yellow zeaxanthin. It is quite
> > possible that Infanta's TTtt genotype reduces its concentration of
> > beta-carotene thus producing its light orange appearance.
> > >
> > >
> > >
> > > Girl Pixie is pink and carries the tttt genotype.
> > >
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