Re: Re: HYB: REB: Genetics of rebloom (was orange)
iris@hort.net
  • Subject: Re: Re: HYB: REB: Genetics of rebloom (was orange)
  • From: B* W* <a*@aol.com>
  • Date: Tue, 15 Mar 2011 13:19:31 -0400 (EDT)
1) << So as you select for earlier bloom, you will very
ikely also be selecting for less cold hardiness.>>
You do mean earlier rebloom rather than earlier spring bloom?
2) <<I just don't think Ca Rebloomers  will ad anything to other rebloom
genes.
ut  there could be a gene interaction.>>
I can't speak for Linda or others following this breeding path, but I am not
hoping to pick up additional rebloom genes from these crosses.  The crosses
are being made to improve form & branching and to add diversity in color and
patterns.  (I've tried to correct the endless sentence and can't!)
3)  <<But as FC genes act as a dominant, it will be tough to get anything
that you
ould for sure say is an effect from Ca Rebloom genes. And in process  you may
e getting  less hardiness>>

Again, I don't want or need additional rebloom genes from the CA Rebloomers.
I want their branching, form, patterns & colors.  As stated before, I'm hoping
the CA reblooomers will not block the summer rebloom genes.  (I'm encouraged
by a few of my seedlings.)  I'm looking for increased potential in the summer
rebloomers.

Seedling slection is very important.  I try not to save or use an inferior
seedling.   You have to be a bit more strict when dealing with a parent that
may be less adapted to northern climates.  Vigor is my number one criteria.
I'm also leaning toward wide fans and generally healthy looking plants.  Can
something behave well here, and then blow it in other climates?  Of course,
but it's a risk all hybridizers take.



Betty W.
Zone 6 KY



-----Original Message-----
From: Chuck Chapman <irischapman@aim.com>
To: iris <iris@hort.net>
Sent: Sun, Mar 13, 2011 6:53 pm
Subject: Re: [iris] Re: HYB: REB: Genetics of rebloom (was orange)



Here is an extract from an article I'm writing
"The temperature trigger for bud set  is same for  FC, Summer and  Cal
ebloomers. Whenever rebloomers are different in this characteristic. That is
bout 6 days with minimum temperatures  between 15 -21C (59B:-72B:F).
ollowing this bud set, the triggers for growing this incipient bud into a
lower stalk is different. A plant can sit at a mature state (as determined by
eaf count on a cultivar by cultivar basis) and not grow, but does not have
ud set until appropriate temperature conditions.
Summer rebloomers grow this bud into a flower stalk immediately, no resting
eriod or further trigger. Referred to a s a direct bloomer.
Fall cyclic and California rebloomers need a further trigger.
For California rebloomers this trigger is a certain amount of time in bud set
tage. Seems to be about 5-6 months. Basically the plant is using a back up
ystem developed by plants originating in a Mediterranean climate. Sometimes
t isnbt cold enough in a Mediterranean winter for a proper vernalization,
o if they have a long time a maturity, plant assumes they must have already
ad a winter. In a Mediterranean climate this works well, but when moved into
 warmer climate (South California and South Australia) where they have longer
rowing seasons, these signals no longer work the same way. Forgive my
nthropomorphism here. The actually term for this is process is facilitative
ernalization. Consider this a dominant gene.
California rebloomers are basically normal plants. That is, no new genes or
ene combinations involved in their rebloom.  A normal trigger, that operates
ifferently then how it does in the Mediterranean climate where it evolved.
hen grown in a climate with a longer growing season,  then where it evolved,
t gets triggered into bloom in the fall, when itbs genetics tell it that
hould be  in a  spring following a mild winter."
By nature of climate you grow California rebloomers in yoiu can't make
election for cold hardiness. And by nature of the genetics, they originate
rom warm climate plants. So as you select for earlier bloom, you will very
ikely also be selecting for less cold hardiness.
I just don't think Ca Rebloomers  will ad anything to other rebloom genes.
ut  there could be a gene interaction.   Others will have to do these
xperiments and report on result.
But as FC genes act as a dominant, it will be tough to get anything  that you
ould for sure say is an effect from Ca Rebloom genes. And in process  you may
e getting  less hardiness
Chuck Chapman




--- Original Message ----
rom: Linda Mann <lmann@lock-net.com>
o: iris@hort.net
ent: Sun, Mar 13, 2011 7:49 am
ubject: [iris] Re: HYB: REB: Genetics of rebloom (was orange)

hanks for the clarification, Chuck, and for the update on what you are
hinking about how this all works.
I know you didn't mention CA bloomers, but as I was typing, that's where the
ogic took me.
<I didn't mention  the California rebloomers.>
Luckily several of us trying to do just that, making crosses in adverse
limates with selections from OZ & CA.  So there should be lots more data
ventually.
<I'm beginning to suspect that  we could  bring rebloom from Ca rebloomers
arlier into season by selection.  But not likely able to increase plant
ardiness unless these are trialed and selected in more adverse climates.>
Can you say a little more about your thinking?   Do you think these two genes
re the same and maybe interact with other growth genes that differ (i.e.,
emperature thresholds, clock time to maturity etc) or ...
<The  summer rebloomers and Whenever rebloomers seem to be a recessive gene
ombined with at least one dominant gene.>
IMMORTALITY is a puzzle as far as passing on rebloom here.  & judging from
how
ew registered offspring it has, I suspect it's a puzzle for others as well,
iven that it seems to be "the" rebloomer that reblooms just about everywhere
n the planet.  I haven't really tried to use it for that much yet, but really
id expect to see more than just one rebloom seedling from it X MATRIX, since
oth are summers here. The cross wasn't all that strong, & last year was
aiden, so maybe this year will yield a clue or two.
Not sure how IMM behaves elsewhere, but here it gets carried away producing
ncreases rather than blooming.  Low stalk to fan ratio, which it passes on in
bout half the crosses.  Usually the ones happiest in my growing conditions.
t's a "fault", but I wonder if it is somehow related to IMM's ability to
loom so often here.  I'm still amazed that one clump of it bloomed last
ugust during heat and drought.
Linda Mann east TN USA zone 7
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