HYB: Paltec
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- Subject: HYB: Paltec
- From: S* M* <7*@compuserve.com>
- Date: Tue, 19 Sep 2000 15:12:46 -0400
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Message text written by Dennis Kramb:
>
Is Paltec totally sterile? Is it diploid? I just received a piece of it
and started wondering if I could use it in my hybridizing efforts.
<
The easy question first: PALTEC is a 26-chromosome diploid.
Whether you use it really depends on your basic approach to hybridizing --
so, for the benefit of any newcomers who may share your curiousity, I'm
going to digress a bit in answering that part of the question.
At one extreme is the hybridizer who wants to be able to cross any two
breeders with the expectation of a reasonable number of seedlings of
predictable type. Many have followed this proven path to success. To
join them, you must limit your breeding stock to members of the same
fertile family. They would tell you to forget about PALTEC and I would
agree completely, IF this were the approach you had chosen.
At the other extreme is the experimenter who is more interested in
information than introductions. Not only is this the "path less traveled",
but the iris world may remain completely unaware of them. Tom and Wiloh
Wilkes are an exception that quickly come to mind. They did introduce a
few iris, but their significant contribution was a combination of
information and breeding stock. They made a lot of crosses exploring the
origin and future possibilities of the C. G. White amphidiploidlike
hybrids. Wiloh corresponded with many hybridizers and freely shared
seedlings, as evidenced by the frequency these appear in registered
pedigrees. Tom wrote technical articles for both AIS and ASI
publications. PALTEC is just the type of subject that such experimenters
relish!
Now, should you choose to take up the challenge....
Purge the word "sterile" from your vocabulary. Fertility is relative.
PALTEC is an interspecies diploid, like WILLIAM MOHR but with different
ancestry. Consider how long WILLIAM MOHR was dismissed as "sterile" and
then look at the long list of offspring that were produced after compatible
mates were discovered. PALTEC's current position is much like that of
WILLIAM MOHR until the late 1940s -- except that, according to TWOI, it is
probably the sole survivor of its type.
We have the advantage now, though, of knowing more about chromosome
conjugation and that means we can confidently map out an experimental
program for it.
1. Cross PALTEC with tetraploid beardeds. This is most likely to
produce BBB- or BBT-type triploids, but can sometimes produce a BBBT-type
tetraploid. Cull the BBBs by selecting for tectorum characteristics.
2. Cross F1 seedlings back to PALTEC. It's a long shot, but
unbalanced diploids do sometimes produce unreduced gametes and an F1's
BT-type gametes are the right type to fertilize an unreduced gamete and
thus produce a fully fertile amphidiploid in the second generation.
3. Cross F1 seedlings among themselves. Not quite as much of a long
shot, but among all the non-viable combinations is the BT + BT, so this is
another way to get a fully fertile half tectorum in the second generation.
4. Cross F1 seedlings with tetraploid beardeds to widen the bearded
portion of the gene pool. Again, cull any BBB- or BBBB-types by selecting
for tectorum characteristics.
What we can NOT predict is how long it will take to get any F1 seedlings at
all, or any F2 seedlings -- much less when the fertility barrier might be
broken. But you can certainly have some fun along the way.
Sharon McAllister
73372.1745@compuserve.com
