science.howstuffworks.com/environmen...d-bank2.htm
A seed bank is only as good as the seeds it houses. Our planet hosts millions of varieties of plant species. Who decides which types of seeds should be stored? All of them? Only the "best" ones? How deep is this library of seeds?
There are about 1,400 seed banks around the world, so which seeds get chosen for storage varies from location to location. Local seed banks may focus on the storage of indigenous wildflowers or specialty vegetables, for example. Other banks have a more global focus. For example, the Global Crop Diversity Trust concentrates solely on a selection of priority crops determined to be the most globally beneficial.