Re: HYB: tetraploids & colchicine
- To: Multiple recipients of list <i*@rt66.com>
- Subject: Re: HYB: tetraploids & colchicine
- From: S* H* <w*@hargray.com>
- Date: Thu, 30 Apr 1998 20:26:53 -0600 (MDT)
> 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. 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?
The members of the Series Hexagonae (Louisiana Iris) are:
I. hexagona
I.fulva
I.brevicaulis
I.giganticaerulea and
I.nelsonii, the natural hybrid of I.fulva and I.giganticaerulea
I.versicolor is not part of the series but there are reported hybrid crosses
between I.brevicaulis x I.versicolor and I.fulva x I.versicolor. I.fulva has
also been crossed with I.spuria, I.virginica and I.pseudacorus
Tetraploids can theoretically be created by crossing triploids (e.g. TRIPLE
TREAT) with diploids. In practice, this does not often happen as triploids are
seldom fertile (there are no fertile seed of TRIPLE TREAT). Using colchicine to
double the chromosome count of diploids is much more likely to be successful.
There are a few tetraploid Louisiana iris (e.g. the PROFESSOR group) but it is
not nearly as advanced as development of tetraploid TB's.
Regards
Stephen HopkinsSo.Carolina, USA
