Techniques for conservation of genetic resources

There are two major alternatives for the conservation of genetic resources: in situ and ex situ.

• In situ conservation refers to the conservation of important genetic resources in wild populations and land races, and it is often associated with traditional subsistence agriculture.
  • If the focus is only on agricultural varieties, the approach is only partially effective because traditional crop varieties, though much more diverse than elite varieties, are themselves much less diverse than wild populations and wild relatives.

  • An attractive approach is to combine nature reserves focused on protection of wild races and wild relatives with traditional agricultural practices. Note: we shouldn't expect traditional farmers to forgo the substantial economic benefits that may attend the switch to elite varieties. This may require direct economic subsidy or conservation of traditional varieties in some other way.

• Ex situ conservation refers to the conservation of genetic resources off-site in gene banks, often in long-term storage as seed.
  • Seeds of many important tropical species are recalcitrant, i.e., difficult or impossible to store for long periods.

  • Many crop plants are clonally propagated. Storing seed does no good, and tissue culture techniques for long-term storage are poorly developed.