permaculture

[Lee Barnes <lbarnes@primeline.com>]

Lee Flier wrote:
> 
> Hey all -
> 
> How does everyone feel about tree propagation through tissue culture?  Call
> me paranoid, but I'm a bit leary of it.  Seems to me that it would greatly
> reduce genetic diversity, and even if a particular strain were bred to
> resist the disease of the moment, it would seem to be particularly
> vulnerable to being wiped out by a disease of the future.
> 
> I don't feel tissue culture is in the same league with propagation from
> cuttings, not only because the cuttings one could get from a single tree
> would be limited, but also the individual branches of a tree contain
> slightly different genetic material, do they not?  (hence branches which
> have seedless fruit, etc.)
> 
> Any comments about this would be appreciated.
> 
> = Lee =
> 
> ==================================
> Lee A. Flier
> lflier@mindspring.com
> http://lflier.home.mindspring.com
> Atlanta and Ellijay, Georgia, U.S.A.

From: Lee Barnes, Happy Trails Permaculture, Waynesville, NC. Katuah
Bioregion (S. Appalachian Mts.)
Re: Plant Tissue Culture
Lee Flier et al, Plant tissue culture has many varied applications for
plant propagation, mutational breeding, virus elimination, etc. We could
have long conversations about the advantages and disadvantages of plant
tissue culture (I have my PhD -1985 in micropropagation of three
endangered trees of northern Florida. Contact me by email or phone if I
can provide more info). Basically, micropropagation techniques duplicate
standard asexual propagation practices (but requires aseptic lab
conditions which are very expensive and relies on high tech equipment
and skilled labor.) I agree that massive clonal propagation should be
viewed with caution since there is no genetic diversity for adaptability
or resistance to stresses, etc. Many tissue culture techniques can be
used to expose or "create" new mutations, cell fusions, etc. that will
result in beneficial cultivars being produced. Producers may "clean-up"
many old plant varieties of internal diseases and viruses, and find ways
of propagating many plants which are difficult or impossible to
propagate. Micropropagation of existing shoot tips meristems is highly
reliable in producing genetic duplicates, but mutations do (rarely)
happen in the lab so propagators need to judge and rouge off-types (or
at least monitor the variations seen).

Someone else asked about the problem of rooting type and possible plant
decline. Cloned plants usually form adventitious roots which differ from
seedling roots in many ways such as branching patterns, by not
necessarily forming taproots, etc. This could be an advantage or
disadvantage depending on the species and cultural conditions. It is
hard to beat Mother Nature's time tested genetic diversity  and growth
development packaged in each seed.

I am a confessed horticulturist, a plant manipulator who is also a
dedicated seed-saver and bioregional activist. World food production
will not be solved by cloning, but rather by honoring and protecting
existing genetic diversity. This includes dedicated seed saving but also
preservation of remaining natural communities and restoragion of damaged
ecosystems. Each of our regions natural forest communities are our best
models for truely sustainable agriculture. We must strive to better
understand and maintain the natural systems which support us with much
diversity. Eating low on the food chain and "eating in season" of
(primarily) locally produced and marketed crops, and using low tech,
appropriate food storing strategies (drying, fermenting) is critical for
our personal and planetary health.

Happy Trails, Lee Barnes 704-452-5716.