In the 50's that was probably hybrids created using cross-polination. And I think that's only true of some hybrids.
Some of the Frankenfood like the genetically engineered corn, does self-reproduce, because farmers have complained that the genetic traits are jumping into adjacent fields.
So I think we have already crossed that bridge.
Maybe we have. My money is on transgenic chickens. It's going to be the Island of Doctor Moreau down here on this planet if we don't watch out.