Re: CULT: rot avoidance vs rot management (was aspects of rot)

Bill B. in Mississppii said
<I expect most hybridizers make a conscious effort to avoid introduction
of
                       rot prone irises.>

I agree - however, sometimes the 'big guys' do introduce 'weak growers'
and mention it in describing the cultivar.  STARSHIP ENTERPRISE was
described as not being a strong grower (I think).  Keith Keppel used to
talk about his "biodegradeable" breeding lines,  & said in his catalogue
that he moved to a worse climate to improve his ability to select
tougher seedlings.  (hope I'm not quoting him incorrectly - apologies if
so)

.<....the plant is worthy of introduction regardless of rot tendency
since the fallacy is already so prevalent in irises in general.>

So, are you saying that 'the fallacy' (rot?) is so prevalent in irises
in general that hybridizers intentionally introduce new cultivars with
that fallacy?  Not sure I understand what you meant...

< Genetically speaking, in breeding can be just as responsible for
eliminating
                       rot susceptibility as it can for creating that
susceptibly. Out crossing has
                       no higher probability or lower probability for
increasing or decreasing that
                       susceptibility either. The deciding factors being
selection of the initial
                       parents and evaluation of the seedlings and their
offsprings.>

Definitely.  My point is that hybridizers working in 'iris heaven'
climates have a MUCH greater pool of genetic material to work with than
I do (and probably ever will have), a lot of which won't grow all that
well elsewhere. The opportunities for 'aha, this mixed with that will
produce something new and interesting' are much greater, but the
opportunity for rot sensitivity is also much greater.  Looking at
pedigrees of irises hybridized in various parts of  iris heaven, most of
the interesting breaks (? not sure that's what I mean, because the ones
I've thought about are combinations of a lot of bloom qualities...) come
from inbred lines that dont' have a lot of supertough components.  If
there are suitable parents that are much tougher but still carry the
'right' genes I feel quite certain that hybridizers in iris heaven would
be using them, if they know about them.

<If indeed there is a gene responsible for rot susceptibility, >

From everything I've been reading re: pathogenesis related proteins,
hormone production, not to mention nutrient availability, moisture
stress, grub, cricket, & borer damage etc etc, it's inconceivable to me
that rot sensitivity would be the result of the presence of one gene.
Rot results from the way the individual cultivar or even the individual
plant at any given time responds.

<....once that gene  is incorporated in a line, for practical purposes,
it is always there no matter how many crosses are made or how unrelated
the two parents are. >

Assuming rot susceptibility is a suite of genes and modifiers, dependent
on all kinds of external stuff, I think so too.

However, if rot susceptibility is the cumulative result of a lot of
genes and modifiers, with the worst rotters having a hard time staying
alive even in iris heaven, then cultivars can have almost an infinite
combination of rot susceptibility, depending on which combinations of
problems they can't cope with - good example is CELEBRATION SONG, which
is an absolute weed for me and rots/blooms out in NM (or is it AZ? -
sorry Francelle - somewhere in the southwest where it's hot and near
desert climate).  In other words, from what I see of rot, it doesn't
appear to be a simple - rot prone/not rot prone situation.

<I suspect, but do not know, that this gene exists as a recessive in
virtually all pink irises for example.>

I had two starts of PINK FORMAL - after a few years, one nearly died
(more gravel, less shade); the other is doing very well, sets pods, and
has produced 4 rampantly growing, rot defying bee pod juveniles (born
this spring).  Gary Sides OCTOBER SPLENDOR is another tough one here -
very slow growing, but no signs of rot (that I've noticed).  It has been
growing adjacent to the start of PINK FORMAL that died.

<I believe it is too late to close the barn door. I believe the gene
pool so mixed and mingled that untangling it is virtually impossible.>

I hear that a lot, but I'm not sure I believe it.

<I do not want to do without lace, the modern flower form, branching,
rebloom or triple  sockets. I do not want to be without pink irises, or
lumanatas, plicatas,
 reverse bitones, amoenas, or bitones. I am a greedy person.>

Aren't we all <g>.  Iris that don't rot here have lace, modern form (I
don't like the horizontal falls, but like modern substance & width),
excellent branching, rebloom, and even a few (ugh <g>) triple sockets.
There are pinks, luminatas (CLARENCE), plics, amoenas, & bitones galore
that aren't particularly rot prone.  I don't think I have tried any
reverse bitones.

< I do not want to go back to the species irises, select two that never
rot and have never rotted, and attempt to bring them forward to the
forms and improvements of today's irises.  I'm far too impatient, lazy,
and only have about 30 more years to mess with this stuff. >

I've heard that this approach is not for the faint of heart <g>  But you
don't have to go THAT far back to get rot resistance.

<Certainly, I would like an effective treatment to cure soft rot. >

I would too!  Then I could keep the rot prone weaklings alive long
enough to produce viable pollen to cross with the tougher guys.

< I believe your hybridizing objectives admirable nor do I find them out
of step with most other hybridizers.>

Well, I'm not so sure about that....

<The difficulty I see is finding two iris that have never rotted
anywhere to cross with each other. Then they need to be certain colors
with certain  patterns. <g>>

Nah, they just need one set of the right genes, then thru careful
linebreeding and backcrossing, we can wind up right back where we
started from, only 50 yrs later.. oops, we won't still be here...<g>

The difficulty for all of us is identifying the rot resistant ones (for
our conditions) before we buy them and/or finding a sure cure for rot in
case we are wrong.  I think there are a lot of the former & am not
inclined to mess with the latter (unless maybe it's EURHYTHMIC...)

Thanks for your comments Bill - wish we'd get some more 2 cents from
folks.

I broke the Massey F this AM, so am stuck here till the repair guys
come, so am once again talking too much...
--
Linda Mann east Tennessee USA zone 7/8

Tennessee Whooping Crane Walkathon:
<http://www.whoopingcranesovertn.org>
American Iris Society web site <http://www.irises.org>
iris-talk/Mallorn archives: <http://www.hort.net/lists/iris-talk/>
iris-photos/Mallorn archives: <http://www.hort.net/lists/iris-photos/>




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