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<DIV><FONT face=Arial size=2>TITLE: Crop improvement: A dying
breed<BR>SOURCE: Nature 421: 568-570, doi:10.1038/421568a, by Jonathan
Knight<BR> sent by
checkbiotech/Syngenta<BR> <A
href="http://www.checkbiotech.org/root/index.cfm?fuseaction=newsletter">http://www.checkbiotech.org/root/index.cfm?fuseaction=newsletter</A>&<BR>
topic_id=1&subtopic_id=1&doc_id=4645<BR>DATE: Feb 6,
2003</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>------------------ archive: <A
href="http://www.gene.ch/genet.html">http://www.gene.ch/genet.html</A>
------------------</FONT></DIV>
<DIV> </DIV><FONT face=Arial size=2>
<DIV><BR>----------------------------------------------------------------------------<BR>
"Changes in the intellectual-property environment have also taken
their<BR> toll. From the late 1960s onwards, developed nations
introduced a<BR> legal framework of plant breeders' rights,
giving new varieties and<BR> cultivars patent-like protection.
The goal was to stimulate innovation<BR> in corporate labs,
but the reforms also meant that public-sector<BR> breeders
were no longer free to tinker with plants grown from<BR>
commercial seed. "Plant-variety protection was the death knell
for<BR> public breeding programmes," says Michael Gale, head
of comparative<BR> genetics at the John Innes Centre in
Norwich, Britain's leading public<BR> plant-science research
institute."<BR>----------------------------------------------------------------------------</DIV>
<DIV> </DIV>
<DIV><BR>Crop improvement: A dying breed</DIV>
<DIV> </DIV>
<DIV>Public-sector research into classical crop breeding is
withering,<BR>supplanted by 'sexier' high-tech methods. But without
breeders'<BR>expertise, molecular-genetic approaches might never bear fruit.
Jonathan<BR>Knight reports.</DIV>
<DIV> </DIV>
<DIV>Normally, at this time of year, agricultural scientists from around
the<BR>world would be converging on the headquarters of the International
Maize<BR>and Wheat Improvement Center, known as CIMMYT, in Texcoco, near
Mexico<BR>City. They would then travel together to a desert field station
near<BR>Ciudad Obregón in northwestern Mexico to study the current crop
of<BR>experimental wheat cultivars, planted at the beginning of winter.</DIV>
<DIV> </DIV>
<DIV>But not this year. For the first time in half a century, the
research<BR>centre that helped to sow the seeds of the 'green revolution' of
the<BR>1960s and '70s has been forced to skip a cycle of wheat breeding
trials,<BR>because of a lack of money. More than half of CIMMYT's fields in
Obregón<BR>lie fallow, and the trainee plant breeders are staying at home.</DIV>
<DIV> </DIV>
<DIV>CIMMYT is not alone. All over the world, conventional plant breeding
has<BR>fallen on hard times, and is seen as the unfashionable older cousin
of<BR>genetic engineering. "Plant breeding is getting dumped along the
wayside<BR>for not being sexy enough," claims Greg Traxler, an
agricultural<BR>economist at Auburn University in Alabama. Government funding of
plant-<BR>breeding research has all but dried up in the United States and
Europe,<BR>and the World Bank and donor nations have recently slashed their
support<BR>for the Consultative Group on International Agricultural
Research<BR>(CGIAR), the international research consortium of which CIMMYT is a
part.</DIV>
<DIV> </DIV>
<DIV>Meanwhile, a steady push by companies to claim exclusive
commercial<BR>rights to new plant varieties has progressively tied the hands
of<BR>publicly funded efforts at crop improvement. If this trend isn't
halted,<BR>some experts claim, tomorrow's supercrops may end up like many of
today's<BR>medicines: priced out of the reach of much of the developing
world's<BR>growing population. "We are headed down the same path that
public-sector<BR>vaccine and drug research went down a couple of decades ago,"
says Gary<BR>Toenniessen, director of food security at the Rockefeller
Foundation in<BR>New York.</DIV>
<DIV> </DIV>
<DIV>Sowing success</DIV>
<DIV> </DIV>
<DIV>Classical breeders improve crops simply by crossing plants with
desired<BR>traits, and selecting the best offspring over multiple
generations.<BR>Sometimes they use chemical mutagens to disrupt crop genomes, in
the hope<BR>that some of the resulting mutants will have useful new traits.
Crosses<BR>may be as simple as letting two plants grow together, or they may
require<BR>pollination by hand. And for crops such as wheat, one parent must
first<BR>be emasculated to prevent self-pollination. In some ways, breeding
is<BR>like accelerated, targeted evolution, and as long as test crops and
seed<BR>banks are maintained, the possibilities can never be fully
exhausted.</DIV>
<DIV> </DIV>
<DIV>These methods, applied intensively at CIMMYT and the International
Rice<BR>Research Institute (IRRI) near Manila in the Philippines, provided
the<BR>impetus for the green revolution. Breeders produced dwarf varieties
of<BR>wheat, maize and rice that were less likely to fall over in wind
and<BR>rain, and which could carry larger seeds. Thanks to these
varieties,<BR>farmers could use more fertilizer without risking losing their
crops, and<BR>grain harvests in some areas have doubled or even trebled over the
past<BR>three decades.</DIV>
<DIV> </DIV>
<DIV>Central to CIMMYT's success in wheat was the practice of
'shuttle<BR>breeding', in which two seasons of plant selection could be
completed in<BR>one year. Grain would be rushed from the fields in Ciudad
Obregón after<BR>the harvest in April for summer planting in Toluca, near Mexico
City.</DIV>
<DIV> </DIV>
<DIV>This year's cancellation of the Obregón end of the shuttle was part of
a<BR>10% reduction in CIMMYT's programmes in the face of budget cuts, says
the<BR>centre's director general, Masa Iwanaga. This was a result of
the<BR>reduction in support for the CGIAR, which supports CIMMYT, IRRI and
14<BR>other agricultural research centres around the world.</DIV>
<DIV> </DIV>
<DIV>Whereas the CGIAR's funding crisis has come to a head in the past
couple<BR>of years, exacerbated by the global economic downturn, the
world's<BR>academic plant-breeding labs have suffered steady attrition over a
far<BR>longer period. Molecular genetics and transgenic technologies hold
great<BR>promise for crop improvement, and have consumed a growing portion of
the<BR>limited funding pie. University administrators have reinforced
this<BR>trend, tending to replace retiring plant breeders with
molecular<BR>geneticists who are more likely to produce high-profile journal
articles.</DIV>
<DIV> </DIV>
<DIV>Changes in the intellectual-property environment have also taken
their<BR>toll. From the late 1960s onwards, developed nations introduced a
legal<BR>framework of plant breeders' rights, giving new varieties and
cultivars<BR>patent-like protection. The goal was to stimulate innovation in
corporate<BR>labs, but the reforms also meant that public-sector breeders were
no<BR>longer free to tinker with plants grown from commercial seed.
"Plant-<BR>variety protection was the death knell for public breeding
programmes,"<BR>says Michael Gale, head of comparative genetics at the John
Innes Centre<BR>in Norwich, Britain's leading public plant-science research
institute.</DIV>
<DIV> </DIV>
<DIV>Root of the problem</DIV>
<DIV> </DIV>
<DIV>The figures reinforce Gale's view: until the 1960s, breeding for
crop<BR>improvement was largely a public endeavour, but a survey of US
plant<BR>scientists in the mid-1990s found more than twice as many breeders in
the<BR>commercial sector than at universities and government agencies
combined.<BR>And although breeders' skills are still alive in the private
sector, they<BR>are now working to subtly different ends. For seed companies
and<BR>agribiotech firms, the top priority has been developing crops that
can<BR>maximize profits from the intensive agricultural practices that
are<BR>widely used in the developed world. Sadly, there is less money to be
made<BR>in seeding a second green revolution for the world's poor.</DIV>
<DIV> </DIV>
<DIV>In recent years, of course, the big news in the commercial and
public<BR>sectors has been transgenic technology, rather than
conventional<BR>breeding. Genetically modified (GM) crops that are resistant to
the<BR>effects of broad-spectrum herbicides or that carry genes for
insecticidal<BR>toxins have been widely planted across North America -- but
simultaneously<BR>shunned by European consumers, who are deeply suspicious of
the<BR>technology. The welter of media coverage has obscured recent
achievements<BR>in classical breeding, and although breeders generally view
transgenics<BR>as a valuable tool, they stress that conventional breeding is far
from<BR>obsolete.</DIV>
<DIV> </DIV>
<DIV>In fact, for many GM crops, there is a comparable conventionally
bred<BR>variety. The seed company Pioneer Hi-Bred, based in Des Moines, Iowa,
for<BR>instance, produces a conventional, herbicide-resistant oilseed rape,
or<BR>canola, that has similar advantages for weed control as its
GM<BR>counterparts. And whereas the GM 'golden rice', engineered to contain
a<BR>gene that boosts the production of vitamin A by people who eat its
grain,<BR>has attracted much publicity, conventional breeding is also
being<BR>deployed to improve the nutritional value of this staple crop. IRRI
has<BR>produced a cultivar of rice called IR68144 that bears grain rich in
iron,<BR>and so could be used to combat anaemia. Even for crops such as
the<BR>banana, which is unable to reproduce sexually without specialist
human<BR>intervention, conventional breeding may still have a role to play
(see<BR>"Bananas in the fertility clinic").</DIV>
<DIV> </DIV>
<DIV>What's more, the GM crops developed so far generally involve only
the<BR>addition of a single gene. Looking to the future, it's unclear
whether<BR>complex traits, which are thought to involve multiple genes, will
be<BR>amenable to manipulation through genetic engineering. "In the long
term,<BR>you need heat tolerance, salt tolerance, greater yield and so on,"
says<BR>Paul Gepts, a crop geneticist at the University of California,
Davis.<BR>"Some say you can do it with genetic engineering, but we just don't
know<BR>how those systems work and how those genes interact." By
contrast,<BR>practical experience has shown that conventional breeding can be
used to<BR>improve a suite of subtle traits simultaneously.</DIV>
<DIV> </DIV>
<DIV>All of this makes Donald Duvick, who was head of research at Pioneer
Hi-<BR>Bred until his retirement in 1990, concerned about the future of
crop<BR>improvement should the agribiotech giants lose their enthusiasm
for<BR>transgenics. "I worry that the results will be so far in the future
that<BR>industry will say 'we can't wait that long'," he says. If so,
the<BR>depleted public-sector effort in plant breeding may be ill-equipped
to<BR>take up the slack.</DIV>
<DIV> </DIV>
<DIV>There are already hints that some companies are pulling back from
long-<BR>term investments in high-tech crop improvement. Only last month,
the<BR>Swiss-based multinational Syngenta closed its Torrey Mesa
Research<BR>Institute near San Diego, which was a major force in crop genomics.
And<BR>both Syngenta and its US rival DuPont, which owns Pioneer Hi-Bred,
have<BR>recently withdrawn funding from the John Innes Centre. "The industry
is<BR>in turmoil," says Gale.</DIV>
<DIV> </DIV>
<DIV>Against this sombre background, can anything be done to safeguard
future<BR>progress in crop improvement by reviving the science of plant breeding
in<BR>the public sector? There is no easy answer, but some experts suggest
that<BR>the future lies in boosting the power of conventional breeding
by<BR>marrying it to genomic and other molecular-genetic techniques,
while<BR>making a concerted effort to break with the proprietary approach
to<BR>intellectual property that is currently blighting the field.</DIV>
<DIV> </DIV>
<DIV>One beacon of hope comes from a consortium of researchers at
12<BR>institutions headed by Jorge Dubcovsky, a wheat molecular geneticist
at<BR>the University of California, Davis. Its primary tool is 'marker
assisted<BR>selection' (MAS). This technique, enthusiasts claim, could offer to
plant<BR>breeding what the jet engine has brought to air travel.
Traditionally,<BR>breeders have relied on visible traits to select improved
varieties. For<BR>pest resistance, for example, that means examining mature
plants in the<BR>field over successive generations to see which survive best in
the face<BR>of attack by pests, before carrying out new crosses. MAS, however,
relies<BR>on identifying marker DNA sequences that are inherited alongside
a<BR>desired trait during the first few generations. Thereafter, plants
that<BR>carry the trait can be picked out quickly by looking for the
marker<BR>sequences, allowing multiple rounds of breeding to be run in quick
<BR>succession.</DIV>
<DIV> </DIV>
<DIV>Superior breeding</DIV>
<DIV> </DIV>
<DIV>MASwheat, as the consortium is known, aims to select for 23
separate<BR>traits in wheat, conferring resistance to fungi, viruses and
insect<BR>pests. Its members also hope to breed the grain to produce bread
and<BR>pasta of superior quality. Notably, the consortium is making all of
its<BR>marker sequences and research protocols freely available. "If you go
to<BR>our website, you have all the tools to do this anywhere in the
world,"<BR>Dubcovsky says.</DIV>
<DIV> </DIV>
<DIV>For wheat, this admirably open approach was relatively easy to
adopt,<BR>because it is one of the few crops to remain largely in public
hands.<BR>Because wheat is self-pollinating, many farmers simply plant a portion
of<BR>their harvest each year, safe in the knowledge that it will retain
its<BR>desirable characteristics. Not surprisingly, this has restricted
the<BR>interest of commercial seed producers, who don't see a robust market
for<BR>their products.</DIV>
<DIV> </DIV>
<DIV>Elsewhere, however, intellectual property is creating a heavy
burden,<BR>with universities and other institutions facing barriers to the
free<BR>exchange of seed, and restricted access to cutting-edge
molecular<BR>technologies. "I wish it would all go away," says Kent McKenzie,
director<BR>of the California Rice Experiment Station, which develops new
varieties<BR>of the crop in its test fields at Biggs, north of Sacramento.</DIV>
<DIV> </DIV>
<DIV>Extending the MASwheat consortium's approach to other crops may
require<BR>public institutions to band together to end the practice of
granting<BR>exclusive licences to individual companies each time they develop
a<BR>powerful technology for crop improvement. To this end, Toenniessen
has<BR>been meeting with representatives of ten 'land grant' universities
--<BR>which form the backbone of agricultural research in the United States
--<BR>to hammer out a plan. "If those in the public sector worked
collectively,<BR>they could solve their problems," says Toenniessen. He hopes to
pioneer<BR>the approach in speciality crops such as peanuts, broccoli, lettuce
and<BR>tomatoes, in which the seed and agribiotech industry does not have
strong<BR>commercial interests.</DIV>
<DIV> </DIV>
<DIV>Richard Jefferson would go further. His Center for the Application
of<BR>Molecular Biology to International Agriculture (CAMBIA) in
Canberra,<BR>Australia, is trying to put cutting-edge technology for crop
improvement<BR>directly in the hands of developing-world scientists and farmers,
rather<BR>than leaving them to depend on the continued health of labs in
rich<BR>countries. "The money is drying up and that is not going to change,"
he<BR>says. "We need to rethink the way crop improvement is done."</DIV>
<DIV> </DIV>
<DIV>In part, Jefferson says, this will involve the transfer of
transgenic<BR>technologies. But extending access to molecular-genetic
enhancements to<BR>conventional breeding methods will also be crucial.
Researchers at<BR>CAMBIA, for instance, have developed a DNA microarray that
will boost<BR>MAS. In many crops, it is difficult to search for specific
genetic<BR>markers, because very little of their DNA has actually been
sequenced.<BR>But by immobilizing fragments of DNA from a variety of cultivars
on a<BR>microarray and then seeing which of them bind to DNA sampled
from<BR>individual plants, it is possible to look for the presence of
genetic<BR>markers in these plants in the absence of any sequence
information.</DIV>
<DIV> </DIV>
<DIV>This technology has already been adopted by the International Center
for<BR>Tropical Agriculture in Cali, Colombia, for cassava improvement. "It
is<BR>extremely useful," says Joe Tohme, the centre's director
of<BR>biotechnology. By making such techniques freely available, and
allowing<BR>scientists anywhere in the world to tinker with and improve them at
will,<BR>Jefferson hopes to speed progress. Essentially, he wants to create
a<BR>crop-improvement counterpart to the 'open-source' software movement
that<BR>has managed to flourish alongside the proprietary approach of giants
such<BR>as Microsoft, which keep their programs' codes under wraps.</DIV>
<DIV> </DIV>
<DIV>'Open-source molecular agronomy' is certainly a sexier label
than<BR>conventional plant breeding. But will it have sufficient cachet
to<BR>reverse the current decline in public-sector crop improvement? The
food<BR>supply for future generations in the developing world could hinge on
the<BR>answer.</DIV>
<DIV> </DIV>
<DIV>CIMMYT <A
href="http://www.cimmyt.cgiar.org">http://www.cimmyt.cgiar.org</A></DIV>
<DIV> </DIV>
<DIV>IRRI <A href="http://www.irri.org">http://www.irri.org</A></DIV>
<DIV> </DIV>
<DIV>MASwheat <A
href="http://maswheat.ucdavis.edu">http://maswheat.ucdavis.edu</A></DIV>
<DIV> </DIV>
<DIV>CAMBIA <A href="http://www.cambia.org">http://www.cambia.org</A></DIV>
<DIV> </DIV>
<DIV>Jonathan Knight writes for Nature from San Francisco.</DIV>
<DIV> </DIV>
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