Ecoscience: Preserving Genetic Diversity With Seed Banks

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PHOTO: FOTOLIA/JOHNNY007PAN
Seed banks help protect plants, national security and more.

Humankind is fortunate that the extreme seriousness of the
loss of genetic variability of crops is balanced by the
relative ease with which the situation could be
improved. “Seed banks” can, you see, be used to preserve samples of
diverse crop strains, as well as populations of their wild
relatives. The seeds of most species will keep in cold
storage for a number of years before the majority of those
in each sample die. Every few years, then, it’s necessary
to sow the saved seed, allow the plants to mature and
harvest the seeds once again for storage.

The Need For Genetic Diversity

However, although seed banks are simple in principle, their
operation requires skill and care. The preservation of
samples often amounts to little more than allowing the
process of natural selection to choose those seeds that
most readily survive the storage conditions. Unfortunately,
seeds that survive well in storage don’t necessarily
produce plants with the characteristics that are most
useful to farmers.

The rate that a plant strain undergoes selection for
survival in storage can, however, be retarded by frequent
planting out. But it’s also important that seeds be planted in the region from which they came… or at least under
conditions very similar to those that occur in the home
area. Otherwise, the strains will lose their unique
characteristics, because — once again — selection
will gradually adapt them to their new environment.

Seed Banks Are Underfunded

A recent survey, conducted by the government’s General
Accounting Office (GAO), found that seed-bank operations
in the United States leave much to be desired. Our nation’s
main facility is the Department of Agriculture’s National
Seed Storage Laboratory at Fort Collins, Colo. Smaller
collections are held by various federal and state
experiment stations and by commercial seed companies.

The Fort Collins laboratory is currently filled to
capacity. It contains more than a quarter-million stored
seed samples, but only about half are catalogued so that
they’re accessible to plant breeders, and the information
on many samples is inadequate. Worse than that, the
refrigeration equipment suffers periodic breakdowns, and
funds aren’t available for growing out the seeds as
frequently as that should be done.

For example, the bank’s large collection of seeds home
guayule, a plant with high potential as a new
source of natural rubber, hasn’t been planted out since
World War II, and it’s very likely that all of
those seeds have died by now. Indeed, well under half of
the seeds of any planting from the facility’s collections
normally germinate, since they’ve had to endure too long a
wait before being sown. Such low survival rates, of course,
imply strong selection for storage characteristics.

Protecting Seeds Means Protecting the Nation 

Overall, the GAO found that there was no effective
seed-bank system in the nation, and that centralized
management was badly needed. As you’d likely imagine, the
niggardly level of funding for these crucial operations is
near the core of the problem. At present, the federal
government spends a total of about $12 million a year on
germ plasm collection and storage. . . which is less, in
constant dollars, than was spent in 1967! Worse, the Reagan
administration may well cut funding even further.

Now it seems to us that the productive capacity of American
agriculture is clearly an important facet of the security
of the nation. Not only does it abundantly feed our people,
but the surplus production available for export provides a
major portion of the foreign exchange needed to purchase
oil (among other things). Yet each year the United States
devotes only about 6 percent of the cost of a single B-l
bomber to preserving the irreplaceable genetic base of
our crops!

Indeed, for the cost of two such bombers (they run about
$200 million apiece), a network of perhaps 20 experiment
stations, each superbly equipped for gene conservation,
could be established worldwide. And for an annual
expenditure equal to the cost of only three F-18 fighters
(at approximately $30 million each), those stations could
be very well staffed with plant geneticists, botanists, and
support personnel.

A well-managed system would have field crews constantly at
work making seed collections (each of which would be
accompanied by careful notes on the source plants), while
continual planting and reevaluation would insure that the
quality of the stored samples did not deteriorate with
time. A computerized data storage and retrieval system
could be used to connect all the stations — providing
both easy access to material by users and control of
distribution, so that key strains would be represented at
several stations to guard against accidental loss.

In addition to running the entire network of stations, the
hypothetical budget proposed above would be able to support
appropriate local crop subsidy programs. With the
experiment stations coordinating such a system, farmers
would be paid to grow some traditional crop strains in
place of present high-yield varieties. This practice would
assure that extensive plantings of the older strains were
always present in agro-ecosystems, providing a key backup
for the seed-bank operations.

Worldwide Benefits to Seed Banks

And who — you have every right to demand — would
pay for all this? As indicated, the United States
government could easily afford to do so with only a slight
shift in priorities and it would be one of the best
“national defense” investments we could make.

But it would be even more reasonable to run such a network
as an international enterprise. All rich nations should be
eager to participate on a fair-share-of-GNP basis. The
Soviet Union, for example, would not only find such a
system invaluable to help brace up its own — currently
faltering — agriculture, but also reap benefits through
the improvement of American crops, on which it on often
heavily depends.

Poor nations should also participate. In fact, many of the
experiment stations should be located in less developed
countries (LDCs). For one thing, such lands are the
sources of many wild relatives of today’s important crops.
Most poor nations, moreover, have had increasing difficulty
feeding their rapidly growing populations and would profit
from research to develop new crop sources from
wild plants — an effort that will require careful genetic
husbandry to succeed.

Benefits For Less Developed Countries From Seed Banks

LDCs would benefit from the employment of LDC scientists
and local laborers, as well. Furthermore, the stations
could serve as on-site research and training centers in
plant genetics and conservation, which would be of great
value to researchers from other parts of the world.

In capitalist countries, seed companies might be expected
to contribute to the cost of maintaining the system of
stations, probably by paying fees for the use of the
program’s information systems and samples. Major
international seed and/or grain companies might also help
support research and preservation efforts in LDCs. Thus,
there are equitable ways that the relatively small costs of
the system could be shared.

Preserving the genetic diversity of crops is, of course,
just one part of the crucial goal of preserving the
diversity of all life on Earth. But it’s a task
for which the immediate need is evident . . . one that
humanity knows how to perform and one that can be done at a
reasonable cost. Because every delay can result in the loss
of irreplaceable resources, failure to start at once is
insanity.