Re: Re: HYB: spots (was another terminology question)
iris@hort.net
  • Subject: Re: Re: HYB: spots (was another terminology question)
  • From: C* C* <i*@aim.com>
  • Date: Thu, 28 Feb 2013 08:50:14 -0500 (EST)
I don't have time to look up how much variability there is in pumilla. I remember that there is various populations, but that doesn't mean variability in chromosome sets. The variability in aphylla is very unusual, and not likely to be found in other species. Iris aphylla (in 2003 study) indicated that aphylla is rare, and in isolated populations, which allows for genetic drift. (not sure what their definition of rare was, probably more like uncommon) Pumilla is not at all rare, and lots of gene flow between populations, so such type of population differences based on genetic drift is not a likely scenario. 

For information on unbalanced chromome number look at.

http://en.wikipedia.org/wiki/Aneuploidy

Chuck Chapman

-----Original Message-----
From: Linda Mann <lmann@lock-net.com>
To: iris <iris@hort.net>
Sent: Thu, Feb 28, 2013 8:28 am
Subject: Re: [iris] Re: HYB: spots (was another terminology question)

Sooo, with all the bazillion afore mentioned crosses with spotted
pumilas, not 'moving' the pumila spot pattern (as opposed to the
variegata spot), maybe there are some pumilas out there that match
better with some of the existing genetically scrambled up TBs.

Theoretically.

Speaking of the (theoretically) variegata spot, does it occur in I.
pumila?  Or did Jazzamataz get it from I. variegata?  I didn't follow
the pedigree very far for Zing Me.

On 2/28/2013 8:08 AM, Chuck Chapman wrote:

I pulled out a couple of papers I had on hand.  Simonet  in  doctoral
thesis in 1934 looked at a number of aphylla clones. The drawings are 
in

his paper. What was obvious was there was differences in chromosome
confirmation. The drawings don't allow good comparison of arm length,
but satellites were indicated. Of the 7 shown, 6 had chromosomes with
satellites Three had a chromosome pair with satellites on each end. 
One

had 4 pairs of chromosomes with a satellite on each end. One had 4
chromosome pairs with one satellite on one end, one had two 
chromosomes

with one satellite.
Satellites are where chromosomes narrow dramatically, and then bulge 
out

with a short length of a wider area. This occurs at the end on some
chromosomes in some species, both plants and animals.

Another paper "High levels of Genetic diversity in populations of Iris
aphylla ....." Wroblewska et al 2003 found a large variation between
populations of aphylla studied. Including banding pattern differences 
on

chromosomes.
So, there can be chromosome mismatching of aphylla x aphylla crosses 
as
well as aphylla X teraploid with a 12 chromosome full or partial set. 
Or
possibly a full match. Depends on aphylla clone used. And if only a 
few

chromosomes mismatch, sorting out can produce viable offspring in
unbalanced chromosome sets. Or amphidiploids in situations with 4 sets
of 12 chromosomes.
So there is some validity to aphylla X 4n-48 being amphidiploid, but 
it

would appear to be the situation only in some cases, and in others
sorting out could produce tetraploids.

Chuck Chapman

-----Original Message-----
From: Bill Chaney <billchaney@ymail.com>
To: iris <iris@hort.net>
Sent: Wed, Feb 27, 2013 6:41 pm
Subject: Re: [iris] Re: HYB: spots (was another terminology question)
Thanks Tom for the info and insight. I think the aphylla derived MTBs 
have

proven themselves fertile with most classes, with some interesting
exceptions,
usually one way or the other (ie pollen sterile and pod fertile, or 
the
reverse). I find that interesting from an genetic standpoint and 
would love

to learn more about it.


Bill





________________________________
From:
Tom Waters <irises@telp.com>
To: iris@hort.net
Sent: Wednesday, February 27,
2013 1:41 PM
Subject: Re: [iris] Re: HYB: spots (was another terminology
question)

A very typical tet MTB parentage is seen in 'Classic Image'. Of
its four
grandparent, three are ((aphylla X TB) x TB), the fourth is TB x TB.
If
aphylla and TB chromosomes were not homologous, those first three
grandparents should have been sterile, yet two produced a fertile 
seedling
crossed with each other, and the other produced a fertile seedling 
crossed
with a TB. Furthermore, 'Classic Image' itself is fertile, and when 
crossed
with an (aphylla x TB) seedling produced 'Saucy', which is also 
fertile.

This
is not to say that aphylla chromosomes are as homologous with TB
chromosomes
as the TBs are amongst themselves, just to say the aphylla x TB
seedlings
behave more like tetraploids than like amphidiploids.
Tom




Tom Waters
Telperion Oasis ~ www.telp.com/irises


Cuyamungue, New Mexico, USA (zone
6)

----------------------------------------
From: "Chuck Chapman"
<irischapman@aim.com>
Sent: Wednesday, February 27, 2013 11:38 AM
To:
iris@hort.net
Subject: Re: [iris] Re: HYB: spots (was another terminology
question)

I'm just going on what I recall. Re-reading the paper would help.
But remember we have even more generations of SDB X SDB crosses, and
they
still are amphidiploids.

If mismatching is only a few chromosomes. sorting
out will happen over
time. If like SDB, number of generations won't make a
difference.

Chuck Chapman

-----Original Message-----
From: Tom Waters
To:
iris
Sent: Wed, Feb 27, 2013 12:58 pm
Subject: Re: [iris] Re: HYB: spots (was
another terminology question)

Surely not so mismatched as to function as
amphidiploids, not with all
the
hundreds of advanced-generation aphylla/TB
hybrids (tet MTBs) that have
been produced with multiple backcrossings, etc.
Tom Waters

Telperion Oasis ~ www.telp.com/irises

Cuyamungue, New Mexico, USA
(zone 6)

----------------------------------------
From: "Chuck Chapman"
Sent: Wednesday, February 27, 2013 5:10 AM
To: iris@hort.net
Subject: Re:
[iris] Re: HYB: spots (was another terminology question)

I vaguely something.
Unfortunately I don't have time this week to look
it up. but from what I
think I recall, basically it was that aphylla
chromosomes didn't match up well
with the TB chromomes, even if same
number is set. So that crosses with
aphylla X TB were amphidiploid.

We are very lucky with iris species, with so
many being able to cross
and be fertile. This is possible with many closely
related species
that are tetraploids, just because of having two sets of
chromosomes, you get amphidploid , and thus fertility. But we also 
have

many
diploid interspecies crosses that are fertile. This is not the
usual situation
with diploids, in the plant kingdom. It is precisely
because of this that we
are able to combine so many genes and get such
a wide variety of plants,
colours etc.

When I look across so many plant genus, Iris seem to be rater
exceptional in number of species that can interbreed and produce
fertile
offspring. I haven't seen anything even close, in other
genus. eg Roses ,
daylilies, carnations, violets, tomatoes, etc,
usually involve no more then
about 20 (daylillies) the others are much
less. With iris we seem to have at
least 100.

Chuck Chapman

-----Original Message-----
From: Bill Chaney
To:
iris
Sent: Tue, Feb 26, 2013 6:25 pm
Subject: Re: [iris] Re: HYB: spots (was
another terminology question)

I seem to remember someone once quoting a Bee
Warburton article on this
issue.
Does anyone happen to know if that is true,
or better yet have a copy
of such
an article? I think it was in relation to
crosses with I. aphylla
specifically.

________________________________
From:
Tom Waters

To: iris@hort.net
Sent: Tuesday, February 26, 2013 1:41 PM
Subject: Re: [iris] Re: HYB: spots (was another terminology question)

There
have been observations of four pumila chromosomes pairing with four
TB
chromosomes in IBs and (I think) 36-chromosome MDBs. These unbalanced
tetraploids are not completely infertile by any means, and relatively
fertile
ones seem to be becoming more common with time, which I have no
explanation
for. Some used to give a "rule of thumb" that if the bivalents
outnumber the
univalents, some fertility can be expected. If you have the
pairing of four
chromosomes I mentioned, an IB has 12+4=16 bivalents, and
8+4=12 univalents.
We also see partial fertility in the 1/4 aril arilbreds.
I think the
supposition is that unpaired chromosomes do not necessarily
stop the plant
from making gametes, and the unpaired ones just end up in
the gametes
randomly. It's possible to have a viable plant with one of two
extra
chromosomes (or one or two missing ones); these are aneuploids. So
the
fertile
gametes from these unbalanced tetraploids are those that
randomly
receive an
approximately complete set. The probability of that is
small, but
can be great
enough to get some good seeds in some cases.
Tom

Tom
Waters

Telperion Oasis
~ www.telp.com/irises

Cuyamungue, New Mexico,
USA (zone 6)
----------------------------------------
From: "Bill Chaney"

Sent: Tuesday,
February 26, 2013 12:02 PM
To:
"iris@hort.net"
Subject: Re: [iris] Re: HYB:
spots (was
another terminology question)

I don't want to distract the
discussion that
is ongoing, but I can't
resist
jumping in when Chuck brings up
the 12/12/8/8
ploidy because I am trying
to
understand how some of these IBs
are so fertile
with TBs and MTBs.
Especially
if the 12/12 side comes from
aphylla
background. Would anyone care to
comment
on that or point me to a
good
source of information?

Thanks
Bill
________________________________
From:
Chuck Chapman
To: iris@hort.net
Sent: Tuesday, February 26, 2013 8:06 AM
Subject: Re:
[iris] Re: HYB: spots (was another terminology question)
Amphidiploid is
12/12/8/8 these are SDB

There can't be cross overs between
any chromosome
from 8 set and 12 set, as they never pair up in meiosis.
Crossovers only
occur
in paired chromosomes. No pairs = no crossovers. Like,
never ever. If they
ever did, their would be unbalanced chromosomes, and it
wouldn't be
viable.
that is the meiotic cell would die, or any zygote
formed
would die.

IB is
12/12/12/8 So can be pumilla spot, on one of the
chromosomes
from the "8
chromosomes" set.

RE; Chocolate Truffle. TB X
pumilla = SDB
No exceptions.
And for kickers, ruffles" a recessive trait that
just isn't
present in
pumilla
species. So where are genes for ruffles coming
from?
Hell's Fire is a
reddish
black, with multiple dosages of Ae (check
pedigree)
Thus all seedlings
will
be purple in a cross with a yellow. So
are you still
believing this
pedigree?
Chuck Chapman

-----Original
Message-----
From: Linda
Mann

To: iris
Sent: Tue, Feb 26, 2013 10:41 am
Subject: Re: [iris] Re: HYB:
spots (was another terminology question)
Amphidiploid version could.

On
2/26/2013 9:09 AM, Chuck Chapman wrote:

The

pumilla spot is only on the "8
chromosome" set. So can't show up
in TB,
Agree, spots are interesting.

TB
e-register from pumila, first generation.
There is another one
registered as a
TB, but class is probably a typo - it's
IB height.
Others SDB breeding?
fertile IBs? cross overs?

CHOCOLATE TRUFFLE
(Mark Grumbine, R. 2006) Sdlg.
MG04-407-7. TB, 29"
(74 cm), EM S. light
yellow-brown; F. dark mahogany
brown, light
yellow area around beards and
shoulders; beards orange; ruffled.
Hells
Fire X I. pumila, yellow

eagerly
waiting to see the '39 checklist
(Mike, any more TBs registered
from that era
from pumilas?)

Are there more?
What about the pumila spot work that Blyth
was doing,
trying to bring spot
'up' to TB size? Zing Me.
---------------------------------------------------------------------
To
sign-off this list, send email to majordomo@hort.net with the
message text
UNSUBSCRIBE IRIS
---------------------------------------------------------------------
To
sign-off this list, send email to majordomo@hort.net with the
message text
UNSUBSCRIBE IRIS
---------------------------------------------------------------------
To
sign-off this list, send email to majordomo@hort.net with the
message text
UNSUBSCRIBE IRIS
---------------------------------------------------------------------
To
sign-off this list, send email to majordomo@hort.net with the
message text
UNSUBSCRIBE IRIS
---------------------------------------------------------------------
To
sign-off this list, send email to majordomo@hort.net with the
message text
UNSUBSCRIBE IRIS
---------------------------------------------------------------------
To
sign-off this list, send email to majordomo@hort.net with the
message text
UNSUBSCRIBE IRIS
---------------------------------------------------------------------
To
sign-off this list, send email to majordomo@hort.net with the
message text
UNSUBSCRIBE IRIS
---------------------------------------------------------------------
To
sign-off this list, send email to majordomo@hort.net with the
message text
UNSUBSCRIBE IRIS
---------------------------------------------------------------------
To
sign-off this list, send email to majordomo@hort.net with the
message text
UNSUBSCRIBE IRIS

---------------------------------------------------------------------
To sign-off this list, send email to majordomo@hort.net with the
message text UNSUBSCRIBE IRIS

---------------------------------------------------------------------
To sign-off this list, send email to majordomo@hort.net with the
message text UNSUBSCRIBE IRIS


---------------------------------------------------------------------
To sign-off this list, send email to majordomo@hort.net with the
message text UNSUBSCRIBE IRIS

---------------------------------------------------------------------
To sign-off this list, send email to majordomo@hort.net with the
message text UNSUBSCRIBE IRIS
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index