A wide cross in "Liliaceae"

J.E. Shields jshields@indy.net
Sun, 24 Jun 2012 04:47:07 PDT
This is a perennial issue in the plant community.  Basically, Tim and Max 
are right, as far as I can see (I'm a biochemist, not a geneticist).

On the other hand, I did see some wide intergeneric hybrids in 
Amaryllidaceae 20-30 years ago at a small USDA experimental station just 
outside Washington DC.  The hybrids required embryo rescue -- in vitro 
culture -- to survive.  They had essentially no endosperm with the embryos, 
as I recall.  The work was done by Margot Williams working in Dr. Bill 
Ackerman's lab.  I don't recall what cytogenetics Margot may have done, but 
the plants themselves were clearly "monsters."  Grossly distorted leaves 
and flowers.  Some had very heavy textures, so might have been spontaneous 
polyploids.  And those were all within the Amaryllidaceae.  I don't know if 
the work got published before Margot had to leave Bill's lab or not.

So, it can happen; but without compelling evidence at the DNA level, we 
have to assume that they are in 999 cases out of 1000, the product of 
someone's wishful thinking.

I think this might well have been the case with Burbank's wide hybrid; but 
regardless, there is only hearsay evidence that would never stand up in 
court or a scientific journal.

Jim Shields

At 06:05 AM 6/24/2012 -0500, you wrote:


>On Jun 23, 2012, at 11:31 PM, Max Withers <maxwithers@gmail.com> wrote:
>  successfully
> > crossed Lilium pardalinum and Trillium ovatum,
>
> >  Further
> > internet research has reinforced my doubts, as I tracked down the
> > following chromosome counts:
> >
> > Lilium pardalinum 2n=24
> >
> > Trillium ovatum 2n=10
> >
> >
>
>I can't comment on the specifics of those species.  Regarding similar 
>accounts and such here are some things that I've decided:
>
>If an amazing probably impossible cross was made yet no proof is given and 
>no offspring exists, and nobody has been able to recreate it.. It never 
>happened.
>
>In regards to chromosome incompatibility, it is extremely rare that the 
>person making a cross is the same person that did the chromosome 
>studies.  Ie numerous issues exist including misidentified plants and the 
>existence of different chromosome counts within a species.   So if the 
>hybrid does exist then the chances are the chromosome numbers probably did 
>match, just not to the documented numbers for those species.  However, 
>plants can do weird things and still end up being compatible.
>
>I use published chromosome numbers as a guide to what could work, but not 
>to eliminate anything.  It's basically impossible for the average person 
>to truly know what count all of their plants are.  Even some things that 
>"should not" work do and some that should don't.   Experiment !!
>
>Tim Chapman
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Jim Shields             USDA Zone 5
P.O. Box 92              WWW:    http://www.shieldsgardens.com/
Westfield, Indiana 46074, USA
Lat. 40° 02.8' N, Long. 086° 06.6' W




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