Sum and Substance explained ?
- Subject: Sum and Substance explained ?
- From: z*
- Date: Thu, 30 May 2002 12:38:46 +0200
Some of you have, rightly so, questioned why S&S is a triploid
Gary Grosset suggested that S & S is possible an F2 of elatior x
yellow sieboldiana x hypoleuca. The problem is that crossing
diploids will not give rise to triploids or tetraploids but occasionally
that happens All sieboldianas including the fully fertile Elatior have
about 23.5 pg of DNA per nucleus, hypoleuca has 25.5
So lets assume first to cross hypoleuca x yellow sieboldiana -> an
offspring with 24.5 pg. Crossing this with hypoleuca will give an F2
with 25 pg However if some nonreduced eggs are made the result
will be 24.5 + 12.5 = 37.0 That is what I found so that is why I think
it is triploid However I once measured Eagles nest and the result is
36.5= triploid for the edge and 51 for the centre making the centre
containing 4.5 DNA sets, very weird!! If however S& S was a
tetraploid Eagles nest would be with a tetraploid edge and a
hexaploid centre However the assumption that S&S is a tetraploid
is unlikley as it would be impossible to find two parents that when
doubled would give a large plant (only the small korean species
have this amount of DNA ie 17-19 pg)
Conclusion again as in my article: S&S is a triploid This explains
too the weird results in its seedlings, that when S&S is selfed
some are sterile (Garry) and the DNA amounts I found in 10 of its
seedlings So you can now (dis) prove this by just making these
crosses. Actually I already have a hypoleuca x Love Pat...I must
remember this year to cross it with Elatior. Maybe I get a blue S&S!
Ben J.M.Zonneveld
Clusius lab pobox 9505
2300 RA Leiden
The Netherlands
mintemp-16C(5F)
Zonneveld@RULbim.LeidenUniv.NL
Fax: 31-71-5274999
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