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Re: iris DIGEST V1 #502

The time between spring bloom and fall bloom for Queen Dorothy and Immortality is about 8 weeks. That gives time for some maturity. But there still needs a trigger for bloom. The other Summer rebloomers also rebloom here but about 3-4 weeks later. For example Again and Again.

Above 40C, most plants put out a chemical to protect themselves from heat damage. This would likely vary between plants. I suspect Forever Blue did that this summer during our hot dry weather. Thus the difference in rebloom times. between yourself and Louisville. Not all plants do this. I had a number of plants in a cold greenhouse , and it got very hot in the summer. Still Rosalie Figge bloomed in August, about 3-4 weeks ahead of when it bloomed outside.

I have Romantic Evening, Pure as Gold , Cantina, and Renown. There has never been bloom on Romantic Evening or Pure as Gold outside. I did get bloomstalk on Pure as Gold in greenhouse in November, but it froze off before blooming. Cantina and Renown rebloom here. But Early to mid September. Later then that, this year.

Hot temperatures have been reported to undo estivation chemicals.

We still need a bloom trigger. If it was just time to maturity, then these others should rebloom here and earlier.

All SDB are half Iris pumilla, with the two sets of 8 chromosomes, and the other two set are two sets of 12 , from mixed species. The sets of 8 don't exchange genetic information with the two sets of 12 as they are amphidiploid.

One thing that happens when you mix genes from different species, is the bio-chemical signals sometimes misfire. That is because they have different pathways etc and when some things change, they don't work the same way. Thus some of what we see with rebloom could be mixed signals, such as cultural differences where body language can convey very different messages. Thus a trace back to species would unlikely produce any useful information. As we are no longer dealing with a species, but a mix.

Some of Dykes crosses of two clones of aphylla, produced a rebloomer. The rebloom wasn't there in either clone, but in the combination it was. Any species that has wide latitude distribution, will develop latitude clines. That is the bloom triggers, specifically photoperiod, can vary from from latitude to latitude. When different clines are crossed, the offspring have a bloom time between the two parents. And, the triggers don't work exactly the same. This made a difference between two aphylla clones, and these are more closely related then the mix we have now. Trigger signals sent, but the receptor is different then what it was expecting, and vice-versa.

We have the biology and the environmental triggers of the biology. We need to identify both.

It seems clear that we are dealing with three different sets of genes. I checked my records and this year I had fall cyclic rebloom on some of FB seedlings. Some on a cross of FB X Autumn Tangerine, a fall cyclic rebloomer. Also on a cross of FB with Summoned Spirit. Summoned Spirit has no rebloom blood that I can tell, but it has the same incredible growth rate that FB has.

So my experiments with FB go as such. FB crossed to summer bloomers, Immortality, Queen doroty Baby Blessed, Cry baby etc, yields nada, incompatible genetics. FB crossed to fall cyclic reboomers, Autumn Tangerine, Victoria Falls, yield fall cyclic rebloomers, some compatible genetics. Thus three sets of separate triggers that have gone awry.

I would suspect that Romantic Evening and Pure as Gold as Gold have the same genetics as Immortality and Queen Dorothy, but have some of the modifying genes that are different.

There was an experiment that involved crosses between Iris fulva and Iris tenax. Two species that share an environment, but have species differentiation that involves having bloom times that don't overlap when they are in the same environment. They crossed some of F1 back to each parent, and then compared the bloom times. The F1 individuals all bloomed in same time period. The back cross of F1 to fulva had a varying range of bloom times between fulva and F1. Like wise the cross of F1 to tenex yielded an array of bloom times between F1 and tenax. Thus a mix up of various components of bloom time, not a set time for all F2, as would be expected if one and only one gene was involved. The crossing of different species results in a reshuffling of very carefully balanced genetic triggers, that work differently after the reshuffling. It is not just the species used, but the clone and latitude cline as well.

Chuck Chapman

Date: Thu, 28 Feb 2008 07:00:01 -0500
From: autmirislvr@aol.com
Subject: Re: [iris] Re: HYB: Daylength independent

This is typical since your summer is shorter.? Conditions appear earlier in colder climates.?

Region 7 (TN & KY) usually have their fall meeting the third week of Sept.? People from Louisville often had fall stalks to bring to the meeting,?while I?had nothing.?Louisville is only about 100 miles north of me, but their temperatures cool earlier in the fall.

I started searching the zone 4 & 5 reports for the things that fell between their spring & fall seasons.? A certain group of irises seemed to do so consistently.? Richards in California grows or grew?a number of cold climate rebloomers, and the same irises tended to bloom for him during the months between his spring and summer.? Noting that he really doesn't have seasons . . . but there still was a correlations between the two climates.?

Since I don't live in either climate, my observations are simply speculation based on things I saw as consistent and "ah-ha" worthy.?

Things like Romantic Evening & Pure As Gold did appear on both lists along with Renown, Cantina etc..? Now, this doesn't mean that I ignore the weaker rebloom of the first two, only that I see them as having certain genes or potential that others irises (EX: Silverado) do not.?

Reports are important.?

I get cyclic rebloom, although much earlier then the rebloomers that are cyclic southern rebloomers.?

Date: Thu, 28 Feb 2008 08:54:45 -0500
From: Linda Mann <lmann@lock-net.com>
Subject: [iris] Re: HYB: Daylength independent

Chuck, have you tracked FB's ancestry back to species?  Any
intuition/thoughts/wild guesses as to sources of rebloom?

Anybody tracked back cycle (spring/fall only) vs "summer" rebloomers to

Just wondering if the different types may originate from different
species (aphylla vs ?) or maybe different clones (i.e., time periods) of
aphylla.  Probably somebody has already speculated about this in the
Bulletin or Recorder, but I can't remember.

If some of the summer and cycle rebloomers come from the same source,
that lends support to the idea that summer rebloom might be a series or
dosage effect (i.e., same gene in cold climate summer, cc cycle, and
California summer). With a temperature trigger added to cold climate (or
subtracted from warm climate).

Which would be encouraging since several of us are trying to make 1)
[(cold climate cycle or cold climate summer) X california summer], 2)
sibs of the former, and 3) [(cold climate cycle x california summer) X
ditto] type crosses to get summer rebloom (either cold climate <or>
California) to improve form, increase color range, and get summer (or at
least earlier fall) rebloom.

- --
Linda Mann east Tennessee USA zone 7/8

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