Re: HYB: ploidy

Recent efforts to use triploid IBs for hybridizing have resulted in
quite a few babies also.  A while back, someone on this forum was
putting together a list of IBs known to be fertile.  There was also an
article in the Bulletin about successful crosses with IBs.

I don't know whether "most" babies from these crosses are tets or
triploids or what.  Can't remember whether the article discussed it.

Dave said:
<So, when pairing gametes from a diploid with those of
                     a tetraploid, it would seem to me that it would be
almost inevitable that
                     some small percentage would come out as fertile
tetraploids on a regular
                     basis........   More often an unreduced
                     gamete would pair with a normal gamete to produce a
sterile (or nearly
                     sterile) triploid, which would be a dead end and
produce few

......I have seen many wild triploid
                     hybrids produce fertile seed (mostly cacti, not
Iris, but the principal is
                     the same), even though they aren't supposed to.  In
most cases this seems
                     to be achieved by the production of unreduced
gametes that pair with
                     gametes of the appropriate number from another
plant (often yet another
                     species).  The offspring from these seeds are often
totally fertile with
                     normal ploidies (often they are not).>


--
Linda Mann east Tennessee USA zone 7/8
East Tennessee Iris Society <http://www.korrnet.org/etis>
American Iris Society web site <http://www.irises.org>
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