The People's Seed Bank

Brian Sandle bsandle at
Wed Dec 20 21:39:14 EST 2000

On Wed, 20 Dec 2000, David Kendra wrote:

> "Brian Sandle" <bsandle at> wrote in message
> news:Pine.LNX.4.21.0012201431400.18054-100000 at
> : On Tue, 19 Dec 2000, David Kendra wrote:
> : But you are claiming (i) that any and every tissue culture book deals also
> : with transgenics.  (ii) that though transgening produces a major change in
> : the protein structure of the plant it does not change the genetic
> : structure enough to have any effect on the somaclonal variation of the
> : tissue cultured plants. What percentage figure do you give for
> : signifcance?
> :
> : How about a book title & page reference. If any one has it in, you must
> : have one readily at hand.  And I am interested to see whether it tells
> : genes wedged into varying places in the chromosome, and any effects of
> : that.
> :
> : Dodo
> Brian, Thanks for the nice ending to your comments.  You ask for specifics
> which I was about to cite but after reading your slam at the end you are on
> your own.

No, this is supposed to be a bit educational. Maybe you would like a less
emotive word than `wedged'?

In the biolistic process DNA (genes) is introduced to plant cells via
micro-projectiles. Genes can enter the chromosomes at many different
`sites' and only some of the resulting plants will survive. Many of the
survivors will be somewhat impaired - less photosynthesis might be traded
for more Bt or RR in the choice of which to keep.

The plants which survive are field tested and also examined as to which
site in which chromosome the genes have `lodged.' Then the products from
those are tested for some generations. 

So I was referring to that process when I wrote:

 And I am interested to see whether it tells
> : genes wedged into varying places in the chromosome, and any effects of
> : that.

But I should have added the effects under varying conditions of stress,
heat cycling, drought, fungal, viral and animal pests, varying light

It is claimed that a plant is breeding true after 10 generations when what
percentage of the progeny have their phenotypes and genes cheacked?

Then back-crossing needs to be checked, too. Is there a program keeping a
constant watch on the structures of the transgenic weed rape in Canada?

  It is clear that you lack all common respect for anyone who
> disagrees with you.  I wrote the one line reply during my lunch break while
> scanning the newsgroups.

Thankyou for taking part.

> Sorry that you cant do you own homework.

I suppose that isn't an excuse for delaying the inevitable out of the
knowledge of trouble?


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