Gene (Germplasm) Banks

An institution where valuable plant genetic material is preserved in a viable condition to prevent its loss or extinction is called a gene bank.

Institutions that preserve valuable, threatened plant materials in viable conditions to prevent extinction in the wild or cultivation.

Materials Stored: Seeds, pollen grains, and vegetative parts (corms, bulbs, tubers, tissues).

Utility: Safeguards threatened species and provides genetic material for global breeders to develop novel plant varieties.

Storage Conditions:

• Seeds are the most convenient storage method.
• Maintained in cold, dry environments at –10 to –20°C.
• Seed moisture is strictly reduced to 5% to prevent damage.

1. IPGRI (Rome): International Plant Genetic Resources Institute; evolved from IBPGR (supported by CGIAR in 1974).

2. G-15 Countries: Created a network of gene banks specifically for medicinal and aromatic plants.

3. India:

• National Facility for Plant Tissue Culture Repository established at NBPGR (New Delhi) in 1986.
• The Indo-US Project was initiated in 1988 to establish a national gene bank.

4. CIFOR: Focuses on long-term ex situ conservation of woody plant gene pools.

5. IRRI (Philippines): Developed the widely planted IR 36 rice variety, highlighting the success of international germplasm cooperation.

1. Tissue Culture: A space-saving, cost-effective method for storing large numbers of genotypes and multiplying endangered plants for reintroduction.

2. Shoot Tip Cultures: Eliminates viruses, making it the ideal method for international germplasm exchange.

3. Molecular Markers: DNA markers (RFLP, RAPD, microsatellites, and DNA amplification fingerprinting) facilitate modern conservation strategies.

4. Cryopreservation (-196°C):

• Involves storing materials in liquid nitrogen; essential for recalcitrant seeds and seedless plants.
• Offers long-term storage, prevents ageing, saves space, and maintains genetic stability.
• The overall conservation system spans field collection, disease indexing, in vitro culture, and active gene bank distribution.
• The basic shoot tip process includes culturing, adding a 5% DMSO cryoprotectant, plunging into liquid nitrogen, and eventually thawing in warm water

Basic steps in cryopreservation of shoot tip

Causes of Genetic Erosion:

• Major habitat loss, fragmentation, and overgrazing.
• Targeted management activities like selective thinning or harvesting.
• Revegetation efforts using narrow genetic collections.
• Replacing naturally occurring local plant varieties.

Steps to Stop/Slow Genetic Erosion:

• Preserve natural habitats and create wildlife corridors for animal migration.
• Carefully release new members of a species into their natural habitats.
• Strictly avoid introducing non-native species into local ecosystems.
• Establish seed banks and cultivate non-GM crop varieties.
• Actively guard against genetic pollution.

• Gene banks actively prevent plant extinction by preserving viable seeds, pollen, and tissues for future breeding and conservation.
• Standard preservation involves drying seeds to 5% moisture and storing them at –10 to –20°C.
• For rare or recalcitrant plants, cryopreservation uses liquid nitrogen at -196°C to maintain genetic stability long-term without ageing.
• Advanced techniques like tissue culture save space, reduce costs, and ensure virus-free material for global exchange.
• Habitat destruction drives genetic erosion; combating it requires protecting natural wildlife corridors, avoiding non-native species, and establishing seed banks.