The Rural Voice, 1991-04, Page 28CANADA'S MOST IMPORTANT BANK
The deposits here ensure the future of our food supply
by preserving important plant genetic material in frozen dormancy
In an unobtrusive white building,
tucked in behind the Sheep Showcase
and the Agricultural Museum on the
Central Experimental Farm in Ottawa,
is one of the most important banks in
Canada.
The bank is operated by Plant
Gene Resources of Canada (PGRC),
and the deposits it protects are not
currency or documents, but seeds of
major agricultural crops. Some
92,000 samples of seed, the majority
of them cereals, sit in various stages of
dormancy, in an attempt to ensure that
their unique genetic information is not
irrevocably lost.
PGRC is part of an international
network of gene banks established in
1974 in response to the widening
problem of genetic erosion in agricul-
tural crops. Once only a concern for
specialists, the past few years have
seen terms such as "genetic erosion"
and "biological diversity" become part
of our everyday language as we watch
the unprecedented burning of the trop-
ical rainforests and become aware of
the number of species becoming
extinct every day.
However, the implications of ex-
tinction have been more difficult for
us to comprehend, for as a society we
are used to re-creating things. If all
known copies of Hamlet, for example,
were destroyed or Lost overnight, the
play could be pieced together in its
original form by consulting with the
people who have memorized all or
part of it. The re -written work would
be identical in content and form to the
original, and a play performed using
the re-created script would be indistin-
guishable from one performed using
the original.
This is not possible with living or-
ganisms. Although we have "copies"
of the extinct passenger pigeon in
museums and books, the original bird
can never be re-created from those
"memories" — the biological mould is
gone and can never be regained. If,
• by Ian Wylie-Toal
through great effort, a bird was bred to
look like the passenger pigeon, it
would never be the passenger pigeon.
The geneticinformation of that bird
would be radically different from the
genetic information of the extinct bird,
and so it would live and behave
differently.
The consequences of the irrevers-
ible loss of genetic information for
agricultural crops has been known for
years. In order to create a new variety
of plant, a breeder has to work with
traits that already exist within that
species of plant. If a breeder wants to
make a drought resistant wheat plant,
he or she has to look for that genetic
information in other wheat plants.
The drought resistant characteristics of
other plants, barley for example, don't
"fit" onto wheat, and can't be used in
a breeding program (generally — gen-
etic engineering has made the species
This
terior of the mid term
storage unit, jiving an idea of the
layout.
barrier a little less absolute). As new
crop varieties spread throughout the
world, the old ones are not grown, and
if they are not grown, their genetic in-
formation will be lost. And within
those old varieties are many of the
genetic "pieces" that breeders may
want to create the next generation of
plants.
A partial solution to this problem
has been to organize a worldwide
collection of seeds, with the aim of
gathering and storing as much of the
genetic diversity contained within
each species of crop plant as possible,
both from cultivated and wild sources.
PGRC's contribution to this pro-
cess is twofold. The curator of the
seed bank, Dr. Guy Baillargeon, says
they collect seeds from all crops of
interest to Canada, with a special
emphasis on cereals. As well, they
have an international mandate to col-
lect oats and barley as well as to be a
backup collection for pearl millet. Re-
ferring to the oats, Baillargeon says
that PGRC has "the finest world col-
lection" which includes "all wild
species."
When PGRC receives a seed
sample, either from Canadian or inter-
national sources, the first task is to
enter its "passport" information in a
database. This information includes
such details as where the sample was
collected, who collected it, when the
collection was made, and why.
After the passport information is
recorded, the seeds are fumigated and
placed in mid-term storage (4°C and
20 per cent relative humidity). In
mid-term storage, samples are held in
paper pouches, which allows the seeds
to dry out to ambient humidity while
they are waiting to be assessed. Mid-
term storage units are extremely sen-
sitive to a change in humidity —
leaving the door open for even a
minute will cause the monitors to
register a sharp rise in humidity. This
excess is quickly removed, restoring
24 THE RURAL VOICE