Re: AB: To be or not to be Lady Mohr

In a message dated 3/11/2002 8:48:33 PM Mountain Standard Time, 
laurief@paulbunyan.net writes:


> I'm quite afraid to ask this as I seem to have absolutely NO aptitude for 
> iris genetics, and I'm embarrassed to admit every tutorial you have 
> offered on this list over the last couple years has gone so far over my 
> head as to require telescopic magnification ... but ... am I correct in 
> understanding that the "real" LADY MOHR, as an OGB-, has low fertility, 
> whereas the imposter, as a presumed OGB, has increased fertility?  If 
> this is correct, is the imposter both pod and pollen fertile?  Can it be 
> crossed successfully with TBs or only with other ABs?

You DO have the correct overview, although I didn't supply the nomenclature 
of the period and you've tried to express the situation in modern terms.  The 
catch is that LM is an OB-, not an OGB-, and we don't know whether the 
imposter is an OB or an OGB although it does appear to behave like a halfbred.

The real LADY MOHR seems to be equally compatible with OOBB-type oncobreds 
and BBBB-type TBs.  That is, if you cross her with both types you can expect 
to get relatively few seedlings but roughly an equal number for each type.  
OTOH, the imposter gives relatively few seedlings when crossed with TBs and 
many more when used with halfbreds.

LADY MOHR was officially registered with the pedigree ((Alta California x 
King Midas) x (William Mohr)) X Ib-Mac.  By modern chromosome-set theory, her 
pod parent could have been a BBB-type triploid, an OBB-type triploid, or [if 
Wm. Mohr had produced one of those unreduced gametes for which it was famous] 
an OOBB-type tetraploid.  LM could thus be an OBB-type triploid, an OBBB-type 
quarterbred, or an OOBB-type halfbred.  The answer should lie in chromosome 
counts....

LM was once counted as having 45 chromosomes, which doesn't fit any of those 
scenarios, so there was some speculation that an imposter was already in 
circulation at that time.  Contemporary reports, however, give her pedigree 
as (Alta California x King Midas) X Capitola: (William Mohr X Ib-Mac).  That 
would make LM an OBBB-type quarterbred.   CAPITOLA was counted as having only 
43 chromosomes instead of the expected 44 -- which could well produce a 
45-chromosome quarterbred.  On balance, I believe that the chromosome-count 
supports the theory that her pollen parent was actually CAPITOLA.

> >Didn't expect an easy answer from me, did you?
> 
> Actually, your answer was surprisingly straightforward.  ;-)  However, it 
> begs the obvious question - if I should desire to purchase the "real" 
> LADY MOHR for side by side comparison with my unknown, how and where 
> could I be assured that I was, in fact, purchasing the "real" thing and 
> not just another imposter?

I eventually obtained a LADY MOHR from the HIPS sale, which not only matched 
the photo in Mitchell's book but exhibited the expected breeding behavior.  
You may be able to obtain one from an individual interested in historic iris 
AND hybridizing experiments that involve them.  

In the meantime, you could go ahead and make some test crosses -- you might 
well prove Dave to be right and me to be wrong in this case!

Sharon McAllister


[Non-text portions of this message have been removed]


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