Re: TB: HYB: backcrosses
- Subject: Re: TB: HYB: backcrosses
- From: Linda Mann l*@volfirst.net
- Date: Fri, 18 Oct 2002 12:30:52 -0400
< [TBs] introduced from the 1940s to the present are most certainly
tetraploids. Dorothy Willott in Northern Ohio, Zones 5/6>
Dorothy definitely knows more about this subject than I do, but I think
there might possibly be a few "tetraploids" since the 40s with a few
extra or missing chromosomes (i.e., n=46 or 50). Children of triploid x
tet crosses...
But no diploid TBs since that era.
Memory is fuzzy, but I think hybridizers were still 'adding' genes from
diploids to TB lines in the 50s. & more recently, Hager introduced
several. Going thru the list of cultivars with chromosome counts on the
worldiris website and charting pedigrees, seems like I remember several
of the F2s from that type of cross had extra or missing chromosomes, but
F3s didn't. Not enough reported to say for sure, but seems like that
would still be a possibility.
Sharon McAllister was encouraging trying to breed some of the 50
chromosome cultivars to possibly bring out some new traits.
--
Linda Mann east Tennessee USA zone 7/8
Tennessee Whooping Crane Walkathon:
<http://www.whoopingcranesovertn.org>
American Iris Society web site <http://www.irises.org>
iris-talk/Mallorn archives: <http://www.hort.net/lists/iris-talk/>
iris-photos/Mallorn archives: <http://www.hort.net/lists/iris-photos/>
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