2.4 Methods for Conservation of PGRFA
37
• Furthermore, the objectives and time-frame of conservation determine the
conservation method, e.g., base collection, active collections, working
collections, community seed collections.
These three factors do not independently influence the choice of conservation
method. Rather an interdependency exists between them. Conserving crops with
recalcitrant seeds implies either only a very short conservation time of the seed, or
utilizing in vitro storage facilities, or conserving the crop in a managed natural
environment, e.g., botanical garden. Conservation in botanical gardens is
generally more cost-intensive than the seed storage in genebanks (Virchow,
1996b). Therefore, a country might decide not to conserve specific recalcitrant
PGRF A, even though they are endangered. On the other hand, there might be a
country with the objective of long-term conservation of all their PGRF A. Because
of the lack of appropriate technologies this objective is not operational. The lack
of human resources may also lead to unsatisfactory storage objectives, because
the storage methods are not appropriate for the specific PGRF A to be conserved.
Routine management operations of ex situ conservation include activities as:
• collecting including survey and inventory
• Duplication: for safety reasons the collected accessions should be duplicated
twice and stored long-term at other conservation locations in the so-called
"black box".
• Regeneration of genebank accessions: regeneration is necessary for accessions
of base collections to retain a certain level of seed viability to secure the
longevity of the stored seed.
• Multiplication: the need to multiply seed stock is defined by the recommended
quantities for base collections and the intensive exchange of specific
accessions.
• Documentation management: plant genetic resources can be of any use for
plant breeders or other present or future users only with adequate information.
For optimal conservation and utilization, the basic data (passport data,
characterization data, primary and secondary evaluation data) should be
available for each accession.
• Storage: storing the germplasm in adequate storage facilities is the crucial point
of the whole conservation management.
• Germplasm health management: the accessions should be screened for
pathogens. This is important for the health status of one's own collection as
well as for the introduction and exchange of accessions.
• Germplasm movement: it is increasingly important for the genebanks to
promote and facilitate the distribution of germplasm mainly to plant breeders,
other researchers and to farmers.
Little information is available on the germplasm movement. Only some
genebanks and national programs have drawn up some statistics. Over the past
three years, for instance, the CGIAR centers have distributed an annual average of
over 50,000 accessions to national programs all over the world. (SGRP, 1996).
Similarly, between 1992 and 1994, the USA distributed over 100,000 samples
each year (FAD, 1996h).
37
• Furthermore, the objectives and time-frame of conservation determine the
conservation method, e.g., base collection, active collections, working
collections, community seed collections.
These three factors do not independently influence the choice of conservation
method. Rather an interdependency exists between them. Conserving crops with
recalcitrant seeds implies either only a very short conservation time of the seed, or
utilizing in vitro storage facilities, or conserving the crop in a managed natural
environment, e.g., botanical garden. Conservation in botanical gardens is
generally more cost-intensive than the seed storage in genebanks (Virchow,
1996b). Therefore, a country might decide not to conserve specific recalcitrant
PGRF A, even though they are endangered. On the other hand, there might be a
country with the objective of long-term conservation of all their PGRF A. Because
of the lack of appropriate technologies this objective is not operational. The lack
of human resources may also lead to unsatisfactory storage objectives, because
the storage methods are not appropriate for the specific PGRF A to be conserved.
Routine management operations of ex situ conservation include activities as:
• collecting including survey and inventory
• Duplication: for safety reasons the collected accessions should be duplicated
twice and stored long-term at other conservation locations in the so-called
"black box".
• Regeneration of genebank accessions: regeneration is necessary for accessions
of base collections to retain a certain level of seed viability to secure the
longevity of the stored seed.
• Multiplication: the need to multiply seed stock is defined by the recommended
quantities for base collections and the intensive exchange of specific
accessions.
• Documentation management: plant genetic resources can be of any use for
plant breeders or other present or future users only with adequate information.
For optimal conservation and utilization, the basic data (passport data,
characterization data, primary and secondary evaluation data) should be
available for each accession.
• Storage: storing the germplasm in adequate storage facilities is the crucial point
of the whole conservation management.
• Germplasm health management: the accessions should be screened for
pathogens. This is important for the health status of one's own collection as
well as for the introduction and exchange of accessions.
• Germplasm movement: it is increasingly important for the genebanks to
promote and facilitate the distribution of germplasm mainly to plant breeders,
other researchers and to farmers.
Little information is available on the germplasm movement. Only some
genebanks and national programs have drawn up some statistics. Over the past
three years, for instance, the CGIAR centers have distributed an annual average of
over 50,000 accessions to national programs all over the world. (SGRP, 1996).
Similarly, between 1992 and 1994, the USA distributed over 100,000 samples
each year (FAD, 1996h).