Re: Re: rebloom Auto-tetraploid versus amphidiploid was Hyb spots
iris@hort.net
  • Subject: Re: Re: rebloom Auto-tetraploid versus amphidiploid was Hyb spots
  • From: C* C* <i*@aim.com>
  • Date: Wed, 13 Mar 2013 15:51:12 -0400 (EDT)
History is unlikely to sort out the chromosome pairings. It would seem to vary from cultivar to cultivar. The only way to know for sure would be be via a meiotic division study, with one of the chemicals which arrests development at the right stage. Andeach subsequent generation would be different, depending on the cross.
The classifications re height has changed over the years. So using old records is rather hit and miss. Randolph published several studies of chromosome #'s and published them in AIS bulletin and in his book. Check those sources. 

Chuck Chapman

-----Original Message-----
From: Linda Mann <lmann@lock-net.com>
To: iris <iris@hort.net>
Sent: Wed, Mar 13, 2013 1:41 pm
Subject: Re: [iris] Re: rebloom Auto-tetraploid versus amphidiploid was Hyb spots 

I went back and re-read the chapters on rebloom in TWOI.  It says G.P.
Brown's foundation line came from one of his own reblooming diploids
(variegata? something else?) crossed with Autumn King (n=46). which was
then crossed with AUTUMN ELF, which is in the 1939 checklist as an IB
GERTRUDE X GRACCHUS?.  Both of which are listed as TBs.

Wish I knew what to make of that.

TWOI goes on to say that this 'tetraploid' was then crossed with
AMBROSIA to produce SEPTEMBER SPARKLER, which is in the background of
nearly all of G.P. Brown's subsequent rebloomers, including IMM via
ENGLISH COTTAGE from AUTUMN SENSATION, which comes from both FALL FAIRY
and GREEN DRAGON, both of which have SEPT SPARKLER as grandparents.

TWOI also talks about R. Smith's early rebloom breeding attempts and
that he was specifically looking for fertile IBs - the writeup is a bit
confusing.  It says he was looking for fertile IBs, but then went back
and tested some older ?IB's? and found several that were fertile
tetraploids.?  I guess that means they were fertile in crosses with
tetraploids.

There were also a lot of earlier rebloom crosses with chamaeirises - I
<thinK> TWOI says none of those are in current bloodlines, but am not
sure about that either.  Abandoned by the people who were working on
them at the time, but no idea if these were among those that Brown or
Smith tried to work with later.

I'm sure this has been written about in more detail in subsequent
rebloom recorders or the Bulletin - can anyone point me to a more recent 
writeup?

Just wondering how much amphidiploidy might be affecting the various
types of rebloom inheritance, might help? explain why some types of
rebloom x rebloom crosses don't work as well as others.  i.e., harder
for the other genes needed for rebloom (not just the 4 types of triggers 
Chuck has talked about) to match up right.

Linda Mann

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