Plant Molecular Biology 35: 61–67, 1997.
1997 Kluwer Academic Publishers. Printed in Belgium.
Conservation of rice genetic resources: the role of the International Rice
Genebank at IRRI
Michael T. Jackson
Genetic Resources Center, International Rice Research Institute, P.O. Box 933, 1099 Manila, Philippines
Key words: rice, genetic resources, genebank, conservation, characterization, evaluation
Rice genetic resources, comprising landrace varieties, modern and obsolete varieties, genetic stocks, breeding
lines, and the wild rices, are the basis of world food security. The International Rice Genebank at the International
Rice Research Institute in the Philippines conserves the largest and most diverse collection of rice germplasm. The
facilities of the genebank ensure the long-term preservationof this importantdiversity. In ﬁeld research, factors that
affect long-term viability of rice seeds have been identiﬁed, leading to the introduction of modiﬁed practices for
traits for rice breeding and the economic impact that germplasm utilization has on rice production and productivity.
The application of molecular markers is changing perspectives on germplasm management. International policies
affecting access to and use of rice germplasm are discussed.
Rice is the world’s most important staple food crop,
and the rice genetic resources stored in the Interna-
tional Rice Genebank (IRG) at the International Rice
resent the largest and most diverse collection of rice in
any genebank [2, 9]. In fact the collection comprises
about 20% of all rice germplasm samples conserved
worldwide, donated from more than 110 countries.
The collection of more than 80000 registered samples
generations, modern and obsolete rice varieties, some
breeding lines and special genetic stocks, the 21 wild
species in the genus Oryza [28, 30], and related genera
in the tribe Oryzeae (Table 1). In the future, transgenic
rices that even incorporate alien DNA should be con-
sidered part of the rice genepool, but they are not yet
part of the IRG collection.
Most samples in the collection are landrace variet-
ies of O. sativa. Ecological differentiation involving
cycles of hybridization, differentiation, and selec-
tion was enhanced when ancestral forms of O. sativa
were carried by farmers and traders to higher latit-
udes, higher elevations, dryland sites, seasonal deep-
water areas, and tidal swamps . Two major eco-
geographic races differentiated as a result of isolation
and selection; indica and japonica . The differ-
entiation also involved morphological and serological
characters as well as intervarietal fertility . Selec-
tions made to suit cultural and socioreligioustraditions
added diversity, especially in grain size, shape, and
color, and endosperm properties. Today thousands of
varieties are grown in more than 100 countries .
Genetic erosion and germplasm collection
eties are needed to meet the food demands of ever-
increasing human populations, there is a price to pay
in terms of loss of genetic diversity or genetic erosion.
In many areas, high-yielding modern varieties were
adopted by farmers and the cultivation of the landrace
extinction through changes in land use, extension of
agriculture into marginal areas, and deforestation.
GR: 201001871, Pips nr. 130297 BIO2KAP
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