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Why are Seed Banks Important?

The wild relatives of staple crops used today are the world's repository for genetic diversity and are essential for ensuring future food security. In the early 1970s, a new corn genotype was released in the US, the Texas male sterile (TMS), that has a number of desirable properties and quickly became a popular and highly planted genotype. This breed was resistant to all the common corn diseases, but it was not resistant to a previously unimportant strain of a fungal disease, the southern corn leaf blight. 90% of the corn sowed in the US in 1970 contained the TMS trait and also shared a susceptibility to this fungus. 1/4 of the US corn crop was destroyed in 1970, a loss of over one billion dollars in production. Of the nearly 8,000 varieties of apple that grew in the US about 100 years ago, more than 95% no longer exist. In Mexico, only 20% of the corn types recorded in 1930 can now be found. Only 10% of the 10,000 wheat varieties grown in China in 1949 remain in use. India farmers have over the last 50 years used 30,000 varieties of rice, each adapted to their local environments. It is estimated that in 2005, 75% of the rice planted in India will be one of 10 varieties. Nine varieties of wheat occupy half the US wheatland. 71% of the US corn crop is one of only six varieties, despite the problem that happened only a few decades ago with Texas male sterile corn. India, Afghanistan, and Western Pakistan have all had epidemics in green revolution varieties of wheat, with yields reduced as much as 85% in some years. Year-to-year fluctuations in yields have been greater since the introduction of new, better performing, green revolution breeds that have been widely planted. Maximum production in some years has been traded for reliability and consistency of production. There are short term and long term effects of the reduction in biodiversity brought about by monoculture of specially bred plant varieties. Over the short term, there is an increased use of pesticides as new threats arise because all of the plants react in the same way to these new stressors. Over the long term, there is the loss of biodiversity, reducing reliability of the plants and permanently losing some of the traits that would have allowed the natural plants to react to new stessors without human intervention. Prior to the green revolution, different regions within a country would have a number of different varieties growing that all had their unique ideal growing conditions, a huge amount of biodiversity that allowed to changes if the environment changed ever so slightly. For example, in the US in 1903, there were 408 edible pea varieties catalogued. Only 25 of those varieties still exist in any form, and 96% of the commercial pea crop is from 2 varieties. It is estimated that 90% of the varieties that existed in the US 100 years ago are gone forever, not being grown or stored in seed banks. Seed banks allow these genetic resources to be conserved under controlled conditions, although they are still only a second-best alternative to conserving wild-relatives that are actively evolving to meet current environmental demands all over the world. There are a number of threats to world seed collections, including civil wars, international wars, natural disasters, and other simpler concerns originating from a lack of funding or proper management. Whenever one of these disasters occurs, unique varieties of important crops can be lost forever. In the 1500 or so plant gene banks around the world, these banks had 2 million distinct samples of genetic diversity that had become much less stable than was previously thought and some samples are already being lost due to failing infrastructure, a lack of funding, and political disturbances. The green revolution has tried to help end hunger in Africa by producing plants that have proven high yields, however, they have proven high yields in the West, with water and fertilizer regularly applied. The trade-off is that they have weaker root structures and less of an ability to compete with weeds. These plants are replacing traditional African plants that actually perform well in the African climate and agricultural environment. There is now a movement in Africa to attempt to breed more regionally-appropriate crops and to use conventional breeding of traditional species rather than genetic engineering. The future is going to require that crops produce more food on the same amount of land with less water, more expensive energy, and a changing climate, making crop diversity a hugely important thing to invest in. Crops will need to double their yields within the next 50 years, according to estimates. \"There is no such thing as a post-agricultural civilization\". Smart breeding has a viable future, but having genetic material to work from is very important, which is where seed banks become important. Examples of seeds in gene banks are the dream of some breeders, such as corn that matures in 60 days and beans that thrive at 112 degrees on 9 inches of rain a year. 3/4 of the nation's food supply rely on just nine crop species, not all of which grow well in extreme climates. The nine crop species are wheat, rice, corn, sorghum, millet, potatoes, sweet potatoes, soybeans, and sugar. Wheat, rice, and corn provide half the world's energy intake. These nine species are only found in one or two varieties, making them very susceptible to disease and pests.

Regeneration:

Regeneration is an important, often overlooked, part of story seeds in seed banks. Like all living things, seeds grow old, even in the cold dry conditions of seed banks. The seeds much be planted, grown out, and fresh seeds harvested so that the conservation can continue indefinitely. This also allows new information to be collected about the plants grown by each seed for breeders and researchers to use. Finally, it allows for the creation of duplicates of seeds that can be sent to different seed banks as a safety.