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MANY seed banks may be failing to save the genetic diversity of the plants
they store. Heiko Parzies and his colleagues at the Scottish Agricultural
College in Edinburgh and the University of Edinburgh looked at varieties of
ancient barley from Syria called landraces. They found that landraces stored for
72 years had lost up to 70 per cent of their diversity compared with recent
collections (Heredity, vol 84, p 476). This may be because the seeds
must be sown every few years and fresh seeds gathered to maintain viability. If
only part of a collection is sown, diversity is lost. Deep-freezing is another
option, but Parzies says that most gene banks don鈥檛 have the facilities to do
this. The solution is getting gene banks to change their practices, and
encouraging farmers to grow old varieties in situ, he says.