Gene banks are a type of biorepository that preserves genetic material. For plants, this is done by in vitro storage, freezing cuttings from the plant, or stocking the seeds (e.g. in a seedbank). For animals, this is done by the freezing of sperm and eggs in zoological freezers until further need. With corals, fragments are taken and stored in water tanks under controlled conditions.^[1] Genetic material in a 'gene bank' is preserved in a variety of ways, such as freezing at -196 °C in liquid nitrogen, being placed in artificial ecosystems, or put in controlled nutrient media.

In plants, it is possible to thaw the material and propagate it. However, in animals, a living female is required for artificial insemination. While it is often difficult to use frozen animal sperm and eggs, there are many examples of it being done successfully.

In an effort to conserve agricultural biodiversity, gene banks are used to store and conserve the plant genetic resources of major crop plants and their crop wild relatives. There are many gene banks all over the world, with the Svalbard Global Seed Vault being considered the most famous one.^[2][3]

The database of the largest gene banks in the world can be queried via a common website, Genesys. A number of global gene banks are coordinated by the CGIAR Genebank Platform

Types of gene bank

Seed bank

A seed bank preserves dried seeds by storing them at a very low temperature. Spores and pteridophytes are conserved in seed banks, but other seedless plants, such as tuber crops, cannot be preserved this way.^{[citation needed]} The largest seed bank in the world is the Millennium Seed Bank housed at the Wellcome Trust Millennium Building (WTMB), located in the grounds of Wakehurst Place in West Sussex, near London.^{[dubious – discuss][citation needed]}

In vitro bank

In this technique, buds, protocorm and meristematic cells are preserved through particular light and temperature arrangements in a nutrient medium, which is either a gel or in liquid form. This technique is used to preserve seedless plants and plants that reproduce asexually or that require preservation as clones such as commercial cultivars.^[4]

Cryobank

In this technique, a seed or embryo is preserved at very low temperatures. It is usually preserved in liquid nitrogen at -196 °C. This is helpful for the conservation of species facing extinction.^[5] Cryobanks are utilized for the cryoconservation of animal genetic resources^[6]

Storage of pollen

This is a method in which pollen grains are stored. Using this technique, plants with one set of chromosomes can be made. The pollen is stored in liquid nitrogen. This method is useful for crossbreeding.

Field gene bank

This is a method of sowing plants for the conservation of genes. For this purpose, an ecosystem is created artificially. Through this method, one can compare the differences among plants of different species and can study them in detail. It needs more land, adequate soil, weather, etc. Germplasm of important crops are conserved through this method. 42,000 varieties of rice are conserved in the Central Rice Research Institute in Orissa.^{[citation needed]}