Principles of Plant Genetics and Breeding

located in developing countries, which frequently complain
about not reaping adequate benefits from contributing
germplasm to plant breeding. Consequently,
these nations are increasingly prohibiting free access to
their natural resources.
US historical perspectives
The US Department of Agriculture (USDA) plant
germplasm collection efforts began in 1898 under the
leadership of David Fairchild. Fairchild collected pima
cotton, pistachio, olive, walnut, and other crop materials.
Other notable personnel in the plant exploration efforts
by the USA include the following: S. A. Knapp, whose
rice collection from Japan is credited with making the
USA a rice-exporting country; tropical fruits collected
by W. Popenoe from South and Central America, also
created new industries in the US; and F. N. Meyer
made outstanding collections between 1905 and 1918,
mainly from Asia and Russia (e.g., alfalfa, apple, barley,
melon, elm, dwarf cherry). One of Meyer’s most
notable collections was the soybean. Prior to his
Chinese explorations, there were only eight varieties of
soybean grown in the USA, all for forage. This picture
changed between 1905 and 1908 when Meyer introduced
42 new soybean varieties into the US, including
seed and oil varieties that helped to make the USA a
world leader in soybean production. The current US
system of plant inventory was established by Fairchild.
The first accession, PI 1, was a cabbage accession from
Moscow, collected in 1898. PI 600,000 is a pollinator
sunflower with dwarf features, developed by ARS
(Agricultural Research Service) breeders.
Other efforts
Potato introduction to Europe and the introduction of
maize and millet to Africa and Asia are examples of
the impact of plant introductions on world food and
agriculture. In fact, the Green Revolution depended
on introductions of dwarf wheat and rice into India,
Pakistan, and the Philippines.
Plant introductions
Plant introduction is the process of importing new
plants or cultivars of well-established plants from the
area of their adaptation to another area where their
potential is evaluated for suitability for agricultural or
horticultural use. First, the germplasm to be introduced
is processed through a plant quarantine station at the
PLANT GENETIC RESOURCES FOR PLANT BREEDING 103
entry port, to ensure that no pest and diseases are introduced
along with the desired material. Once this is
accomplished, the material is released to the researcher
for evaluation in the field for adaptation. The fundamental
process of plant introductions as a plant breeding
approach is acclimatization. The inherent genetic variation
in the introduced germplasm serves as the raw
material for adaptation to the new environment,
enabling the breeder to select superior performers to
form the new cultivar.
When the plant introduction is commercially usable
as introduced without any modification, it is called a
primary introduction. However, more often than not,
the breeder makes selections from the variable population,
or uses the plant introduction as a parent in
crosses. The products of such efforts are called secondary
introductions. Some plant introductions may
not be useful as cultivars in the new environment.
However, they may be useful in breeding programs for
specific genes they carry. Many diseases, plant stature,
compositional traits, and genes for environmental
stresses have been introduced by plant breeders.
As a plant breeding method, plant introductions have
had a significant impact on world food and agriculture,
one of the most spectacular stories being the transformation
of US agriculture as previously indicated. One
of the most successful agricultural nations in the world,
US agriculture is built on plant introductions, since very
few plants originated on that continent. The USA either
leads the world or is among the top nations in the
production of major world crops such as wheat, maize,
rice, and soybean.
International conservation efforts
The reality of germplasm transactions is that truly international
cooperation is needed for success. No one
country is self-sufficient in its germplasm needs. Most
of the diversity resides in the tropical and subtropical
regions of the world where most developing nations
occur. These germplasm-rich nations, unfortunately,
lack the resources and the technology to make the
most use of this diversity. International cooperation and
agreements are needed for the exploitation of these
resources for the mutual benefit of donor and recipient
countries.
Vavilov collected more than 250,000 plant accessions
during the period of his plant collection expeditions.
This collection currently resides at the All-Union
Institute of Plant Industry in St Petersburg. The Food