DTSM (asker) Mar 31, 2010:

"страховой генофонд" is a term most probably coined in the nineties by главный белорусский зубровед
http://greenbelarus.info/content/view/800/200/
Google returns only 7 hits for "страховой генофонд" and they are all related to wisent conservation efforts.
I had to hand in my translation before James posted his answer and in my final version it was "conservation gene pool".

James McVay Mar 31, 2010:

I checked back with the biologist, and he said to call it "genetic diversity." Maybe "genetic diversity gene pool"? Or "gene pool for genetic diversity"? I don't think you'll find a closer English equivalent of "страховой генофонд вида."

James McVay Mar 31, 2010:

I asked a biologist ...but I'm not sure the answer helps. This is what he said: "This refers to what is considered adequate genetic diversity within the remaining individuals such that breeding by what is termed an outbred scheme will not result in significant relatedness if the individuals that are produced. In other words, you need enough unrelated individuals so that you are not breeding siblings, first or second cousins."

DTSM (asker) Mar 31, 2010:

@James I agree with 'gene pool' but 'wild stock' does not seem to be a good idea in this case. Страховой генофонд is so called because it provides an insurance against losing rare species. Unlike резервный генофонд, it cannot be used for any purpose other than wildlife conservation.