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HYB: 1/4 x TB Crosses

From: Sharon McAllister <73372.1745@compuserve.com>

Message text written by Donald Eaves:

>> but there have also
>>been examples counted as having three TB sets of chromosomes and one set

>  It's this last that intrigues me.  Why wouldn't this begin to stack aril
genes in
a TB-like plant?  And why wouldn't you begin to line breed here?

Unfortunately, I can cite several reasons:

1.      It's extremely rare, detectable only through chromosome analysis
[which is a tad more demanding than chromosome counting].

2.      The mixed set of chromosomes is less likely to be passed on than
normal sets, and detecting its presence in the next generation is just as
difficult as finding it in the first place.

3.      The gene pool is much too small for line-breeding to be practical.

>  If you
accumulate more aril genes while maintaining TB hardiness, it seems that
line breeding would be the means of doing so.  If I were doing it, it would
the plant I was after, not necessarily how it could be registered.  I
that the genetic knowledge would be important, but I haven't grasped the
whole picture somehow.  It seems to me that the proper selection of crosses
which added more aril genes, even if only bit by bit, would move them
being more accessible as garden subjects.  Those that picked up the less
hardy or more difficult aril aspects could be discarded or used just as the
ones currently are being used.  Fill me in on what I'm not seeing here.

There's nothing wrong with your proposed scenario, except that it is
subject to the limitations I outlined above and there are easier ways of
accomplishing this objective.   The simplest is just selecting seedlings
for growth habits as much as flower characteristics.  

For example, many years ago some of Gene Hunt's introductions were
criticized for having "lost" their signals.  But signals are an onco trait,
at that time still closely linked with onco growth habits.  Gene broke the
link by developing lines with TB cytoplasm and plant characteristics [for
example, WISHED FOR CHILD & KOKO KNOLL] or  regelia cytoplasm and plant
characteristics [for example: ESTHER, THE QUEEN].  With outcrosses, he then
reintroduced signals to these lines, while maintaining gardenability.

Following up on his work, I found that plant characteristics tend to be
most like those of the pod parent.  For example,  EQ gave me far more
selected seedlings when used as a pod parent than a pollen parent, even
though I was able to make many more crosses using its pollen.  That's why
I've come to recommend choosing the pod parent for its expressed plant
characteristics and genetic potential in flower characteristics.  I
certainly don't claim a monopoly on this.  If you study some of Howard
Shockey's last 3/4-bred introductions, which are exceptionally gardenable
for the class,  you'll see that he also capitalized on this principle.

My long-term experiments have also included attempts to accumulate as many
TB genes as possible in a plant with aril cytoplasm, and vice versa --
mostly to learn about the genetics.  [You might want to explore the Sibling
Sheets on my web site to see more about this.]  But there have been enough
payoffs that I can recommend this approach to others.....

For a specific example, let's look at DRESS PINKS.  From (LOVELY BLANCHE x
EUNICE) X SUNRISE IN GLORY, you might expect it to be a halfbred.  Nope. 
Its pod parent was a Hunt seedling, which appears to be triploid [its pod
parent was a tetraploid TB and pollen parent was a diploid RC, so that's
not surprising]. The Hunt seedling wasn't introduced because its only aril
characteristics are limited branching, low bud count and superior substance
-- but it is a clear coral pink [the color that just "doesn't appear" in
arilbreds] and has given me some spectacular seedlings.  

Coming from a triploid x amphidiploid cross, DRESS PINKS could be either of
the parental types.  Extensive testing, however, convinced me that it is a
triploid of limited fertility.  That means it gave me a significant number
of seedlings, but not nearly as many as I'd expect from a halfbred.   The
plants are quite TB-like, although it performs better for me than any TB.
When I saw it in Lu Danielson's more hospitable-to-TBs garden, it was
threatening to take over the place.

So what does this mean for future generations?  Even with its limited
fertility, it's an excellent pod parent for use with half-breds.  That type
of cross takes advantage of its ability to pass on its growth habits, with
a 50/50  chance of fertility in the first generation.  Careful selection of
its mate can also capitalize on its recessive color & pattern.  [Yes, it
even has a small signal patch.]  

That's not to say that DRESS PINKS is the ONLY one of its type worth using
in such a program -- this is just one example.  IMO, any quarterbred with
good growth habits and receptive-to-aril flower characteristics is worth
trying as a pod parent with halfbred pollen.

>  In a way, didn't Mr. Seligmann achieve exactly what aril breeders were
looking for with SATAN'S MISTRESS?  It's got intense color saturation,
strong substance, superior texture on a gardenable plant much like a
TB.  It just didn't have the onco appearance.  But it doesn't quite look
just like the TBs either, tho it's difficult to pinpoint exactly why.  It
somehow to do with the above, but I can't quite explain what it is.  Still
it is a remarkable iris and is selected as THE standout even by visitors
here when it is in bloom.  Without any prompting.  Something is visible
even to the untrained eye or that wouldn't happen.

Yes, in that sense SATAN'S MISTRESS was a success.  But he registered it as
a TB because it didn't have the aril traits most people had come to expect.
 The Coronel was a self-professed "pollen dauber".  He enjoyed raising a
variety of seedlings and showing them off to garden visitors.  His
arthritis had progressed to the point that he was reconciled to giving up
hybridizing about the time I got serious about it so we started working
together.  Sometimes, it seemed like he put up with my study of pedigrees &
planning of crosses only because I'd make whatever crosses he wanted before
spreading my own selections on the remaining fresh flowers in his garden --
but we certainly had fun.  Another MVIS member also stopped by frequently
to make crosses for him, and I still believe their prime consideration was
coming up with outlandish crosses that would get the biggest "rise" out of

>   Soooo, that
means more planning. It's likely that at age 52 this just ends being an
exercise for fun, but I can make it serious fun.

IMO, you still qualify as a youngster!  One of the last letters I got from
Gene Hunt outlined a program he found interesting, "but it would take 40
years".  At the time, he was in his mid-70s -- but he closed that letter 
with "I may try it anyway"!  Unfortunately, he never got the chance as his
life was soon ended by an unfortunate encounter with a drunk driver.  But
he had taken the time to think it through and tell me about it, so I was at
least able to follow through on the portions for which I could find the
requisite breeding stock.

>   May I begin with the above?  If not, what's the best approach
for the first generation end-of-line scenario?

I've tried to answer the above questions, but the approach I'd recommend
for a first-generation, end-of-line scenario is relatively simple:  Follow
the advice I've given before regarding the production of quarterbreds with
aril characteristics.  The TB x halfbred cross and its reciprocal produce
quarterbreds in sufficient quantity for evaluation and selection.  The TB x
quarterbred cross and its reciprocal produce fewer seedlings and only half
of them can be expected to be quarterbreds.  The odds are worse, but the
underlying principles are the same.  The added challenge is simply that of
determining WHICH of the offspring are actually TBs and which are
functional quarterabreds.

1.      Early-season rebloomers not only have desirable growth habits but
also provide an opportunity for a reciprocal cross. In conventional crosses
for quarterbreds, I've found the highest ratio of good seedlings in crosses
with an arilbred pod parent but have introduced more with a TB pod parent
simply because I've had so many more to choose from.  If you want to learn
as much as possible from these experiments, reciprocal crosses will be of
enormous value.

2.      Plicatas, bicolors, and bicolor-plicatas -- expecially those with
pink ground -- are most likely to let aril traits show through. The plicata
pattern is recessive.  Pink is recessive.  Bicolors are a combination of
dominant and recessive genes.  These patterns are more likely to let aril
characteristics be expressed in their offspring than are selfs -- even
light-colored ones that owe their appearance to the presence of a dominant

I've answer on-list because others saw your questions and may be interested
in the answers.  I'll certainly continue the discussion off-list, if you

Sharon McAllister

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