Re: HYB: tetraploids & colchicine

Secondly, I have a number of varieties (color variations) of iris versicolor
>(versicolor is one of the 5 species which contribute genetic material to the
>Louisanas).  Besides colchicine treatments (which I don't know how to do)
>is there any way to get these dips to become tets?

I. versicolor is not involved in the Louisianas.  Tetraploid versicolor
have been produced and seed has been regularly available from SIGNA.  I
have some seedlings coming up now and one or two from last year that may
possibly bloom.  The foliage is much larger and more robust than the
diploids, and growth seems significantly faster.  I do not know how these
tetraploid versicolors were produced.  Tetraploid versilaev (versicolor x
laevigata) seed has also been available; I got three seeds in the fall from
SIGNA and all have germinated.

>I. verna is the sole member of its series, as is i. prismatica the sole
>member of its series (or at least so I have read).  Are there any known
>attempts at crossing these with other series such as Louisianas?  Could it
>work?  Would the chances be better if they were raised from dip to tet
>levels?

Chances of crossing these two species with Louisianas are not at all good.
Verna is perhaps related to ruthenica of Europe.  It has never been used in
hybridizing, though supposedly there was a hybrid with I. pallida at one
time. Prismatica is evidently close to the siberians, and crosses with them
have been made, as well as with I. lactea.

Species books tend to list all kinds of wide, inter-section crosses, based
on old literature reports.  I am very skeptical of such lists, which
include spuria x louisiana crosses, etc., etc. They are usually offered
without any supporting literature citations or even the names of the people
who supposedly made the crosses.

Bill Shear
Department of Biology
Hampden-Sydney College
Hampden-Sydney VA 23943
(804)223-6172
FAX (804)223-6374
email<bills@hsc.edu>
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