Re: HYB: SPEC: I. versicolor

I think if you want success with this cross, your best bet is to get high
ploidy levels in your parent plants.  Then you get enough duplication of
chromosome material from each parent that the incompatibilities are less
likely to affect the viability of the offspring.  Even so, you may well
find them so different that nothing happens anyway.  You might get
pollination, but aborted seeds; you might get some mature seed, but then
these may be unable to germinate; and even if you get seedlings, they may
funk out on you right after they germinate.  If you do get mature
offspring, they will probably be sterile, but the higher the ploidy, the
more likely they will be fertile (at least with one another).  It's
definitely a long shot.  However, plants of perhaps considerably more
distant relationship have been crossed successfully in the past, but it is
a rare thing.

Another long shot way to get them crossed is to physically mix the tissues
from two plants and produce a chimera, but this isn't exactly genetic
hybridization as much as putting the tissue in a blender and seeing what
you get (most often deformity and really ugly plants).  Most often the
resulting plants do not actually have genetic material from both parents
mixed into the same cells, but rather separate cells from the two plants
growing together in a mix (though genetic mixing can apparently occur to
some degree too).  I don't know much about doing this on purpose, but it
can be done if the tissues aren't too incompatible, and it has happed by
accident with great results in the past.  However, the best results are
usually using two plants of the same species with different coloration.
I've never heard of it happening in an Iris (but I've heard the term
misused for Irises with odd leaf or flower coloration).  This is a real
unlikely way for getting anything worth growing, but again, you never know
till you try.  Usually in a chimera, the traits of the two parents to not
actually blend, but occur together in a patchwork sort of like some of
those weird Picasso paintings.

I don't know the ploidy of I. versicolor, because I don't know the base
number(s) involved, but from the count I would guess it is high (likely 8x
or 10x ?), so that seems like a good place to start.  There are cultivars
of TB Iris that have higher ploidies than tetraploid, and they might be
where you want to go for material.  However, I don't know off hand which
ones they are, nor if they are available.  I've heard of hexaploids
(probably +/-72) and octaploids (probably +/-96), but don't remember names.
There is no reason these wouldn't be fertile themselves (depending of
course on parentage, but most TB's have pure base 12 ancestry, with no
reduction in fertility from hybrid incompatibilities).  I haven't heard of
higher ploidies in smaller classes, but they probably exist, and would
probably be good to try too.

Good luck,

Dave

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