Seed Gene Banks

Seed gene banks are technical facilities where plant genetic resources (PGR) are conserved ex situ, outside their natural habitats. These facilities store seeds after drying them to low moisture levels and keeping them at low temperatures for long-term preservation without losing viability. Plant genetic resources serve as a vital source for ensuring food and nutrition security, enhancing the resilience of agricultural production systems, and adapting to future environmental conditions such as climate change. Seed banks are the most common ex situ approach adopted for the conservation of these resources.

Representative Seed Bank (Generated by Artificial Intelligence)

Historical Development

Efforts to collect and conserve plant genetic resources in Türkiye began in the 1920s to meet the country’s food needs. During this period, in 1925, the Sazova Seed Improvement Station was established in Eskişehir under the name Islah-ı Büzûr. Agricultural engineer Mirza Gökgöl collected cereal seeds, primarily wheat, from various regions of Türkiye between 1925 and 1950. He characterized thousands of wheat samples, identifying over 18,000 distinct types and 256 new wheat varieties, and published his findings in the work titled "Türkiye Buğdayları".

Systematic collection and scientific conservation of plant genetic resources began in the 1960s under an agreement with the United Nations Food and Agriculture Organization (UN/FAO). As part of this initiative, the Plant Research and Introduction Center was established in 1964 and later renamed the Ege Agricultural Research Institute (ETAE). Türkiye’s first seed gene bank meeting international standards was established within ETAE in 1972. This institution operates as the National Seed Gene Bank (NSGB).

In 1988, a second gene bank was established within the Field Crops Central Research Institute in Ankara to serve as a security backup for the ETAE collections. This facility moved to a new building on 2 March 2010 and continues its operations under the name Türkiye Seed Gene Bank (TSGB). Both seed gene banks maintain reciprocal security backups of their respective collections. In 1976, the National Plant Genetic Resources Research Project was organized to coordinate Türkiye’s plant genetic resources activities.

Theoretical Approaches and Conservation Methods

Two complementary approaches are used for the conservation of plant genetic resources: in situ (on-site) conservation and ex situ (off-site) conservation.

In situ (On-site) Conservation

This method involves conserving genetic resources within their natural habitats. It allows the evolutionary processes of plant populations to continue within their native ecosystems.

Ex situ (Off-site) Conservation

This method involves conserving target plant species outside their natural habitats. It enables the safe and controlled storage of genetic material. Major ex situ conservation techniques include:

Seed Banks

The most widely used ex situ technique. It is suitable for orthodox seed species that tolerate drying and low-temperature storage. Seeds are dried to a moisture content of 5–6% and stored long-term at temperatures such as -18°C or -20°C. This method offers advantages including minimal space requirements, low labor needs, and the capacity to conserve large numbers of samples at low cost. However, it is not suitable for recalcitrant seed species that are sensitive to drying and freezing.

Field Gene Banks

This involves maintaining living collections of perennial plants propagated vegetatively, such as fruit and vine crops, or species whose seeds cannot be stored easily. This method facilitates the evaluation of material in breeding and research programs. However, it has limitations including the need for large land areas, high maintenance costs, susceptibility to diseases and pests, and vulnerability to climatic conditions.

In Vitro Conservation

This technique involves storing plant tissues or cells under slow-growth conditions in a laboratory environment. It provides ease of access for research purposes but is less preferred for long-term conservation due to high maintenance costs.

Cryobanks (Cryopreservation)

This method involves freezing plant materials such as seeds, meristems, and embryos in liquid nitrogen (-196°C) or in the vapor phase of nitrogen (-130°C to -196°C). These ultra-low temperatures halt all metabolic activity, allowing materials to remain intact for extremely long periods. It is a cost-effective method due to minimal space requirements and the absence of regular renewal needs, but species-specific protocols must be developed for each type.

Pollen Conservation

This involves storing pollen to enable cross-pollination between plants that flower at different times, particularly in breeding programs. This method preserves only the nuclear genes from the paternal parent, and the pollen of many species cannot be stored for extended periods.

DNA Banks

This is an emerging technique in which genetic information is stored in DNA form. While effective and suitable for long-term preservation, technical challenges remain in reintroducing isolated DNA into viable plants.

Applications and Functions

Gene banks are facilities where genetic material is safely conserved, cataloged, and made available to scientists and plant breeders. Their main functions include:

• Conservation of Genetic Diversity: They create a reservoir of genetic material for future breeding programs by preventing the loss of genetic diversity in local varieties, wild relatives of crop plants, and other wild species.

• Providing Resources for Breeding: Plant breeders use materials from gene banks to develop new varieties resistant to diseases and pests, and tolerant to abiotic stresses such as drought and high temperatures.

• Supporting Food Security: Conserved genetic resources contribute to the sustainability of agricultural production in meeting the food demands of a growing global population amid changing climate conditions.

• Supplying Research Material: Gene bank collections provide material for scientific research in fields such as genetics, genomics, botany, and taxonomy.

National Seed Gene Bank (NSGB) Collection and Operations

The National Seed Gene Bank (NSGB) carries out the mission of conserving Türkiye’s plant genetic diversity. As of 2024, the NSGB collection contains over 55,000 accessions representing approximately 3,090 species.^【1】 The biological composition of the collection is as follows:

67% are local varieties,

32% are wild relatives of cultivated plants and other species collected from natural flora,

1% are modern (registered) varieties.^【2】

When categorized by plant groups, cereals lead the collection with 12,667 accessions. Vegetables (11,340 accessions), food legumes (9,983 accessions), and forage crops (9,057 accessions) follow in sequence. Among cereals, wheat (Triticum sp.) accounts for the largest share at 47%^【3】.

The NSGB operations encompass the following key activities:

• Conservation: Collected seed samples are divided into two sets. One set is designated as the “base collection” and stored at -18°C for long-term conservation and is not available for distribution. The other set is maintained as the “active collection” at 0°C for medium-term storage and is available for distribution.

• Distribution: Seed samples from the active collection are distributed upon request for research and breeding purposes. Distribution is conducted under a signed “Material Transfer Agreement” (MTA), and users are required to report their research outcomes.

• Regeneration: Seed samples whose viability or quantity falls below established standards are re-produced under controlled conditions to preserve their genetic integrity.

• Documentation: Data on collection (passport), conservation, characterization, and distribution for each conserved accession are recorded in a database for easy access and management.

• Herbarium: Dried plant specimens corresponding to the seeds conserved at the NSGB are stored in the ETAE Herbarium, registered in the international herbarium index under the code “IZ”.