Keith,
This is encouraging; using some of the tricks of biotechnology to
enhance traditional breeding techniques.
No gene contamination.
The goal: Improved crops and livestock
The technique: Marker Assisted Selection (MAS)
MAS helps to select the "parents" that offer the best potential for
breeding success even if the desired features are determined by many genes.
As I understand it:
Genetic markers are easily identified DNA segments, or genes that
confer traits that are easy to recognize. They have been used to determine
which organisms were successfully transformed .... genetically modified.
Ex: How do you recognize which soybean cells were transformed to be
resistant to the herbicide "roundup" or sunflower cells that produce their
own pesticide? Include in the DNA to be spliced into their DNA a segment of
DNA that enables them to glow in the dark when exposed to UV light. If they
glow in UV, they have the "desired" gene as it was attached to the glow in
the dark gene..
Marked Assisted Selection (MAS) seems to be a way to help identify
organisms that are the best candidates for passing desirable traits to
their offspring. As mentioned in the article, most genetic modifications
involve traits determined by a single gene pair. Most features in plants and
animals, including those of greatest agricultural significance are the
result of polygenic (many genes) inheritance and/or the interaction of
several gene pairs.
Because of this two organisms with the same phenotype (appearance) may vary
significantly in the reproducibility of the desirable features. One is a
better candidate for breeding than the other ..... how do you select? MAS
helps breeders make the decision w/o having to perform several test
breedings.
Although most features are determined by many genes, often one gene
has greater significance than the others. This gene is sometimes referred to
as a "major gene". The marker in MAS is an easily recognizable segment of
DNA that is associated with, or even a part of the desirable form of the
major gene. The presence of the marker suggests the presence of the
desirable major gene.
This, along with the Pedigree Studies of classical breeding would aid in the
selection of best organisms to mate and should accelerate improvements in
crops and livestock.
Far less threatening than transgenic organisms.
Tom
----- Original Message -----
From: "Keith Addison" <[EMAIL PROTECTED]>
To: <biofuel@sustainablelists.org>
Sent: Thursday, July 06, 2006 9:21 PM
Subject: [Biofuel] Beyond Genetically Modified Crops
http://www.washingtonpost.com/wp-dyn/content/article/2006/07/03/AR2006
070300922_pf.html
Beyond Genetically Modified Crops
By Jeremy Rifkin
Tuesday, July 4, 2006; A15
For years the life science companies -- Monsanto, Syngenta, Bayer,
Pioneer Hi-Bred, etc. -- have argued that genetically modified food
is the next great scientific and technological revolution in
agriculture and the only efficient and cheap way to feed a growing
population in a shrinking world. Nongovernmental organizations,
including my own, the Foundation on Economic Trends, have been cast
as the villains in this unfolding agricultural drama, and often
categorized as modern versions of the English Luddites, accused of
continually blocking scientific and technological progress because of
our opposition to genetically modified food.
Now, in an ironic twist, new, cutting-edge technologies have made
gene splicing and transgenic crops obsolete and a serious impediment
to scientific progress.
The new frontier is called genomics, and the new agricultural
technology is called marker-assisted selection, or MAS. This
technology offers a sophisticated method to greatly accelerate
classical breeding. A growing number of scientists believe that MAS
-- which is already being introduced into the market -- will
eventually replace genetically modified food. Moreover, environmental
organizations that have long opposed genetically modified crops are
guardedly supportive of MAS technology.
Rapidly accumulating information about crop genomes is allowing
scientists to identify genes associated with traits such as yield,
and then to scan "crop relatives" for the presence of those genes.
Instead of using molecular splicing techniques to transfer a gene
from an unrelated species into the genome of a food crop to increase
yield, strengthen resistance to pests or improve nutrition,
scientists are using MAS to locate desired traits in other varieties
of a particular food crop, or its relatives that grow in the wild.
Then they cross-breed those related plants with the existing
commercial varieties to improve the crop.
With MAS, the breeding of new varieties always remain within a
species, thus greatly reducing the risk of environmental harm and
potential adverse health effects associated with genetically modified
crops. Using MAS, researchers can upgrade classical breeding and
reduce by 50 percent or more the time needed to develop new plant
varieties by pinpointing appropriate plant partners at the gamete or
seedling stage.
While MAS is emerging as a promising new agricultural technology with
broad application, the limits of transgenic technology are becoming
increasingly apparent. Most of the transgenic crops introduced into
the fields express only two traits -- resistance to pests and
compatibility with herbicides -- and rely on the expression of a
single gene. This is hardly the far-reaching agricultural revolution
touted by the life science companies at the beginning of the era of
genetically modified crops.
Of course, marker-assisted selection researchers emphasize that there
is still much work to be done in understanding the choreography --
for example, between single genetic markers and complex genetic
clusters and environmental factors, all of which interact to affect
the development of the plant and produce desirable outcomes, such as
improved yield and drought resistance.
So, of course, a word of caution is in order. It should be noted that
MAS is of value to the extent that it is used as part of a broader,
agro-ecological approach to farming, one that integrates introduction
of new crops with a proper regard for all the other environmental,
economic and social factors that together determine the
sustainability of farming.
The wrinkle here is that the continued introduction of genetically
modified crops could contaminate existing plant varieties, making the
new MAS technology more difficult to use. A 2004 survey conducted by
the Union of Concerned Scientists found that non-genetically modified
seeds from three of America's major agricultural crops -- corn,
soybeans and canola -- were already "pervasively contaminated with
low levels of DNA sequences originating in genetically engineered
varieties of these crops." Cleaning up contaminated genetic programs
could prove to be as troublesome and expensive in the future as
cleaning up the viruses that invade software programs.
As MAS technology becomes cheaper and easier to use, and as knowledge
in genomics becomes more dispersed and easily available over the next
decade, plant breeders around the world will be able to exchange
information about "best practices" and democratize the technology.
Already, plant breeders are talking about "open source" genomics,
envisioning the sharing of genes. The struggle between a younger
generation of sustainable agriculture enthusiasts anxious to share
genetic information and entrenched company scientists determined to
maintain control over the world's seed stocks through patent
protection is likely to be hard-fought, especially in the developing
world.
If properly used as part of a much larger systemic and holistic
approach to sustainable agricultural development, MAS technology
could be the right technology at the right time in history.
Jeremy Rifkin is the author of "The Biotech Century" and president of
the Foundation on Economic Trends.
© 2006 The Washington Post Company
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