RE: SPEC-X: Christy's seedlings
From: Bill Shear
Auurgh, here we go again.....
>> Originally, the cross was reported as having been made BOTH ways, now
as JI X Sib only.<<
Perhaps you misunderstood. I have said all along that I used pollen from
*both* Siberians on *both* JIs. FYI, my notes from 1992 show that both JIs
>> Now if it was JI X Sib only, it becomes very difficult to explain, <<
Which is exactly the reason I've been trying to enlist the help of as many
skilled people to find out as much about these plants as I can. Know any
>> A survey of wide-cross progeny in the history of iris breeding shows
that the F1 generation is almost always a mix of the characteristics of
Not necessarily. I've heard hybridizers speak of dozens of crosses that
should have been perfect but show no hybrid characteristics. The knee-jerk
reaction is to throw the whole lot on the compost because they don't fit
the stereotype. Anything that might have been learned is lost.
>>The evident easy fertility of both the original cross, repeated several
times, and the offspring with the parents and among themselves, also does
not fit what we know of plant genetics. <<
Then, perhaps we just don't know as much as we think we do about plant
I am still testing to try to find out who likely came from which exact
pairing. The seedlings *will* cross easily with their own kind. To be
perfectly clear... There are 2 distinct kinds of SIB types suggesting
different parentage. *In controlled crosses*, the SIB types will cross to
SIB types and the easiest crosses will be those who have exactly the same
parents in common. They will not cross as easily to related pure Siberians
and I have not been able to cross them at all to unrelated Siberians.
The JI types show the same kind of behavior.
I have gotten only 1 cross of opposite type F1s and am seeing reasonably
consistent takes using JS-C pollen on the SIB type F1s. Crosses to pure JIs
have shown no positive results except for ROSE QUEEN. Since pure JIs do not
tolerate our heat and drought well, I have had few chances to try such
>> Wouldn't you reasonably expect that from types as divergent as JI and
Siberian, which have never been crossed before in the history of iris
breeding, the progeny would be sterile or almost so?<<
Indications are that as the seedlings are becoming more balanced in
appearance they are also becoming less fertile. The seedlings from the
cross of 92JS2A and SUMMER SKY are nearly all sterile.
>> The chromosome counts (at least one of them) suggest intermediacy,<<
*One* count showed only 24 C as is common with JIs. The other *three*
showed 26 C.
>> cytogeneticists routinely repeat such counts many times. Was Sam's
count from one cell or did he survey several cells and root tips (assuming
the count was made using root tip cells)? <<
The counts were made using root tips and Sam told me he repeated them a
number of times to be certain they were correct. I have the Polaroids of
the clearest of those spreads.
>>The 26-chromosome plant should certainly be sterile or have limited
fertility with either parent, because it would produce 13-chromosome
gametes, and in crosses with either parent there would be a univalent
Fertility *has* been limited in parent X seedling and seedling X parent. It
could also explain the high mortality rate in those crosses.
>> was dismayed at the quotes from "The Experts Speak," a mischievious
little book that suggests that "experts" are usually wrong,<<
Lighten up! I tossed it in to underline the fact that experts are not
always right just as novices are not always wrong. Judgements, by anyone,
can only be made using the facts available at the time. When new
information surfaces that doesn't seem to fit, I would rather find out why
than simply discard the information and cling to the safety of established
ideas. How many of the people quoted would be considered experts today if
they had stopped searching for an answer because a guess was wrong or
because conventional wisdom at the time said something was impossible.
>>When the original crosses are repeated by a second hybridizer or even a
third or fourth, under rigorously controlled conditions and repeated
chromosome counts or intermediate appearance and limited fertility confirm
the results, I'll be happy to switch.<<
Let me see if I have this straight....
Someone else.. a REAL hybridizer (or 2 or 3) must duplicate the cross under
laboratory conditions and have C counts done repeatedly.
If these plants had looked intermediate and were sterile from the first,
they would also have offered no chance to learn, no chance to develop new
types, and no challenge to those who believe there is more to learn of
genetics than is already on the books.
As frustrating as it's been at times, I'll go with the chance to learn
something new rather than settle for immediate gratification and plants
which are genetic dead ends.
THE ROCK GARDEN
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