Re: HYB: Tetraploid Nomenclature
- To: Multiple recipients of list <i*@rt66.com>
- Subject: Re: HYB: Tetraploid Nomenclature
- From: T* T* L* <t*@rt66.com>
- Date: Fri, 28 Mar 1997 11:31:58 -0700 (MST)
Sharon writes
:
:An AUTOTETRAPLOID is a special type of tetraploid that has four sets of
:chromosomes from the same species. Examples: a cultivar with only I.
:stolonifera ancestry, or one with only I. pumila ancestry.
and just to be a nuisance, I'll remark that I. pumila is not a very good
example of an autotetraploid, because it apparently resulted from a natural
hybrid of I. attica and
I. pseudopumila, so that two of its chromosome sets are noticeably
different from the other two (refer to the idiogram on p.152 of _TWoI_). A
purist would probably describe I. pumila as an amphidiploid or at least an
allotetraploid. However, the attica and pseudopumila sets apparently pair
very readily, so for practical breeding purposes I. pumila behaves like and
autotetraploid.
What breeders need (and don't have) is a standard terminology for plants
that _breed like_ autotetraploids, amphidiploids, or unabalanced
tetraploids, even when those terms are not technically applicable because
of the multiple species involved in their background.
I sometimes refer to effective autotetraploids as "full tetraploids", but
I'm not really happy with the lingo.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Tom Tadfor Little telp@Rt66.com
Iris-L list owner * USDA zone 5/6 * AIS region 23
Santa Fe, New Mexico (USA)
Telperion Productions http://www.rt66.com/~telp/
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