Re: RE: HYB: Getting It Straight For the Simple Minded - RePost

Hi, Steve,
    Yes, it does help to have the genetics of hybridizing explained.  I did
some equine breeding years ago, so I have a slight understanding of the
process.
Sorrel (red) is the Dominate gene in horse breeding and an easy color to
produce,
unlike the elusive red iris.   But between horses or irises, I prefer the
irises.
They step on me alot less and don't eat near as much!!  Happy Irises to You!
Vicki


----- Original Message ----- 
From: "Steve Szabo" <steve@familyszabo.com>
To: <iris@hort.net>
Sent: Tuesday, May 10, 2005 9:31 PM
Subject: RE: [iris] RE: HYB: Getting It Straight For the Simple Minded -
RePost


> Vicki,
>
> I'm the Steve Neil refers to. I am, more or less, like you when it comes
to
> iris and other plants (maybe worse).  I see something I like, I buy it,
and
> then plop it in the ground. If it grows, fine, If it doesn't, something
else
> takes its place. (See, maybe worse than you <g>.) I do have another hobby,
> where I am familiar with the taxonomy, and the genetics, or, at least how
> the genetics work. I don't know how long you've been on this list, but,
> eventually, you'll see the heavy duty threads on hybridization and
genetics,
> among other things, if you haven't already. In these threads, there are
> assumptions made that others understand the underpinning of iris genetics,
> at least to some extent. I just wanted to try to gain that ground for
those
> of us who do not understand this stuff, so, perhaps, we can follow those
> threads a bit better, with a greater understanding.
>
> Now Neil is retired, as I understand it. Perhaps I will be retired
sometime
> in the future. Mayhap, then, I can put some work into doing a little
pollen
> dabbing as well, and se what happens. Then, again, by then I may be truly
> simple minded <g>.
>
> \\Steve//
>
> -----Original Message-----
> From: owner-iris@hort.net [o*@hort.net] On Behalf Of Vicki
> Gatling
> Sent: Tuesday, May 10, 2005 8:32 PM
> To: iris@hort.net
> Subject: Re: [iris] RE: HYB: Getting It Straight For the Simple Minded -
> RePost
>
> Gosh, after reading this email, I feel so "simple minded".  As a newcomer
to
> the iris world, all I know about an iris is if I think it's pretty or not!
> And I know how to grow the ones I like.  But I am glad there are others
that
> DO know  about hybridizing them!  You smart ppl just keep developing new
> pretty ones and I'll just keep looking at them!!  Thanks!  Vicki Gatling
>
>
> ----- Original Message ----- 
> From: "Neil A Mogensen" <neilm@charter.net>
> To: "Iris-talk" <iris@hort.net>
> Sent: Tuesday, May 10, 2005 5:42 PM
> Subject: [iris] RE: HYB: Getting It Straight For the Simple Minded -
RePost
>
>
> > Steve, you have asked some questions about which I believe a number of
> > others may also have a degree of curiosity.  I will make an attempt to
> > respond "for the Simple Minded."
> >
> > There is a difficulty about reducing what is incredibly complex stuff to
> its
> > essential elements without making hash of what occurs in the conception
> and
> > birth of new plants from the sexual process.  Plants are not quite as
> simple
> > as animals, but the matter is actually pretty much the same except for a
> few
> > matters that make no difference as far as your question is concerned.
> >
> > Normal "simple" plants and animals have two matched chromosomes in the
> > cell's nucleus for each chromosome in their basic set.  These are
> "diploid"
> > organisms, a word from Greek meaning simply "two-fold."
> >
> > The pollen and the egg are "haploid," also Greek, meaning "half-fold."
> Each
> > of those chromosomes is unique, and the "how many" is described as the
> > "x=number," even though one often sees the expression misstated as
> > "n=number."  I'll use "x" below.
> >
> > Old diploid bearded irises from Europe, like *I. pallida* or *variegata*
> and
> > the hybrids between them have an "x" of twelve.  There are twelve
unique,
> > different chromosomes in the set.
> >
> > With bearded irises, around 1890 or so a few irises collected in Asia
> Minor
> > (modern Turkey) and other areas scattered from Greece to Afghanistan and
> > Kashmir on the border between Pakistan and India began to drift into
> > circulation in England and France, and later in the United States.
These
> > clones,
> > species, or whatever (some confusion reigns about these identities),
> several
> > of which are still available, were larger, heavier plants, bigger
blooms,
> > but almost monotously blue-violet bitones in color .  AMAS is one of
those
> > collected clones, and is listed by a number of major growers for its
> > historical interest.
> >
> > Many crosses were attempted between these Asiatics and garden varieties
of
> > bearded irises.  Very few of the crosses were successful, and when they
> > were, usually only had one or two seeds.
> >
> > It turns out that many of these Asiatics have the same "x=12" of the
> > European irises, but have a total of forty-eight chromosomes, where the
> > older, colorful and hardy European varieties had only twenty-four.  They
> > were "tetraploid," again, the same Greek, but with "four" as the first
> part
> > of the word.
> >
> > What happened to account for these one or two seeds is that something
had
> > gone awry during development of the occasional ova (or more rarely, the
> > pollen grain) that was involved in these hybrid seedlings, and the
result
> > was a "tetraploid" hybrid because *all* of the diploid parent's
> chromosomes,
> > two of each, had gone into the ovum or sperm (pollen grain), and when
> > fertilized with the Asiatic, produced colorful, beautiful, big hybrids
> that
> > were fertile.
> >
> > All of our "tetraploid" TB's are descended mostly from these hybrids.
> >
> > In a few cases, natural, wild tetraploids of *I. aphylla,* and *balkana*
> > have entered into the mix, and some other diploid species such as the
> dwarf
> > *suaveolens,* *reichenbachii,* (which also has a tetraploid form, I
> > believe), *imbricata* and others have been mixed in also.
> >
> > You may notice that Jim and Vicki Craig in Oregon have a line of
> tetraploid
> > Miniature Tall Bearded irises (which are a classification normally
diploid
> > in their chromosome makeup) that have been bred down in size by the use
of
> > normal Tall Beardeds with *I. aphylla* in complex pedigrees.
> >
> > None of this has depended on the chemical "boost" that colchicine has
been
> > used to double the chromosome counts in JI's and Siberians.  Tetraploid
> LAs
> > also exist.
> >
> > Your question about the arils and aril hybrids is a more complex one.
The
> > "x" of Regelia (Hexapogon) irises is eleven, and that of the Oncocyclus
is
> > ten.
> >
> > Several decades ago various people in California and elsewhere began
> trying
> > to get hybrids between these aril irises from the Middle East, from
Israel
> > to Iran and Turkey and the bearded irises.
> >
> > By an extraordinary streak of luck a hybrid occurred sometime before
1910
> > between the diploid Oncocyclus species *iberica* with twenty chromosomes
> and
> > the collected wild tetraploid Macrantha.  This produced a hybrid with
all
> > twenty of the chromosomes from the Onco, and the normal half of
> twenty-four
> > from Macrantha.  Following a rule no longer allowed, the species name
and
> > Macrantha were combined as IB-MAC, which has pollen that is quite
fertile.
> > It has forty-four chromosomes, four "x" counts, two each of the ten from
> the
> > Oncocyclus set, and two sets of the twelve from Macrantha
> >
> > When these chromosomes pair up to begin the process of pollen or ovum
> > formation, the ten Oncocyclus chromosomes pair with the other ten like
> > themselves, and the same thing happens with the twelve from the TB
> > Macrantha.
> >
> > This behavior makes the plant behave as if it were a normal diploid with
> an
> > "x" of twenty-two.  However, that isn't what the hybrid is.  So a new
term
> > comes in.  This is "Amphidiploid," again using the Greek.  There are
other
> > amphidiploid hybrid varieties and a few species among other kinds in
> irises.
> >
> > Modern ABs that are neither "+" nor "-" are only slightly more
complicated
> > than this.  They often involve a mix of chromosomes from the Regelias,
the
> > Oncocyclus and the various classifications of Beardeds.
> >
> > That evolution has had the hands of many heroic, extraordinarily patient
> > people mixed in.
> >
> > Your comment, "Arilbred iris are crosses with various bearded iris and
> aril
> > iris. For the most part, these crosses are fertile" opens a Pandora's
Box.
> > The truth is, by far the largest majority of the early crosses produced
> > hybrids that were as sterile as they could be.  It was only by
> extraordinary
> > persistance, and according to one source I ran across years ago, helped
> > along through the throwing of IB-MAC into the mix, that the jump up to
> > "amphidiploid" fertile hybrids occured. This history makes great
reading,
> > and I highly recommend it.
> >
> > Curiously, there are other possibilities than "tetraploid," by the way.
> >
> > If I remember rightly, edible modern potatoes are a product of some
> > extraordinary collecting and plant breeding by South American Natives
that
> > involve at least five different wild species.  They are "Octoploid,"
> meaning
> > "eight-fold" in their chromosome makeup.
> >
> > Such things as "triploids" and "penta-" and "hexa-" hybrids of various
> kinds
> > also occur, including in irises.
> >
> > In animals, on the other hand, any combination above diploid is usually
> > fatal.
> >
> > Neil Mogensen  z 7  Reg 4  western NC mountains
> >
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