Date: Wed, 24 Sep 1997 17:22:12 +1000 From: Andrew Bernuetz <andrewb@camden.usyd.edu.au> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg3675$foo@default> Subject: Re: inbreeding, etc
Jeff writes:
>A simple way to begin producing new cp clones/varieties/cultivars is
>careful breeding of selected plants. Inbreeding will allow mutations to
>surface that may have been hidden and if desirable tissue culture can be
>used to quickly propagate the individual clone(s).
Rand replied:
>I am not sure if you mean to use the term "inbreeding" in quite the fashion
>that you have. Are you talking about recessive genes expressing themselves
>through inbreeding?
I guess he is.
>If so, these types of expression most often lead to things such as
>albinism, single testicles, congenital dysplasia, sterility and other such
>abberations which are not lightly tolerated in nature for any length of
>time.
Yes, but many other traits are also recessive, but beneficial. Also, you
are relating back to animal genetics in which inbreeding is less tolerated
than in plants, which ofetn have higher levels of tolerance due to
polyploidy and other factors. Did you know that commercial wheat and oat
cultivars are both so inbred as to be almost totally homozygous? This is
why they grow true from seed, as with many other inbreeding plants.
>I would rather save the species and the habitats that are left. I
>believe this would be more in focus with the "conservation" part of the
>subject header of your post:
I totally agree, but wouldn't it be better if some breeding work was done
to make the plant more easily grown/more attractive, etc, while also
maintaining the original wild material?
> "Re: Production of new CP varieties and conservation"
>I believe that hybridization is a judgement call and desirability depends
>upon perspective. Having said that:
>Skeins of "purebred" dog lines have been genetically disfigured by
>"inbreeding for **desirable** traits."
This is usually due to 'too much' inbreeding, how else is it possible to
produce a uniform breed?
>Other examples of ornamental breeding gone wrong by "scientific method"
>abound.
Can you name any?
>This is not to condemn ligitimate research, but to suggest that we quite
>likely have started down a long road without really knowing where we are
>going.
With many things this is the case, but how can you know where you are going
if you have never been there before, it is a road of discovery.
>"It ain't as simple as all that."
>Why not look for and to the marvellous plants that are already out there
>(in this CP context), try to understand and preserve them, and leave nature
>to make the variants, or mutants, for us to find? By most reports, there
>are enough of them out there. Surely we are not so bored?
The problem with finding mutants, or leaving nature to produce them, is
that it takes a long time, and in nature only mutants which are
advantageous in the environment in which they are growing will usually
survive and prosper.
Andrew
Andrew Bernuetz
University of Sydney
Plant Breeding Institute
107 Cobbitty Road, Cobitty
Private Bag 11 Camden NSW 2570
Australia
Phone +61 02 9351 8804
Fax: +61 02 9351 8875
Email: andrewb@camden.usyd.edu.au
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