Wiktionary
seed stock
n. 1 (context literally English) A stock of seed. 2 Any supply for planting in general. 3 (context figuratively English) Any source of new (notably young) individuals.
WordNet
seed stock
n. a supply of seeds (or tubers) reserved for planting
Usage examples of "seed stock".
Despite the range of computerized equipment on the dock, from overhead-tracking forklifts that could shift multi-ton reactor cores to tweezerlike micromanipulators capable of extracting the black specks of monocloned seed stock from radiation-resistant transport gel, there was still a need for the kind of sheer muscle mass that could break open a wooden packing crate from one of the low-tech trading worlds.
They also took selected traditional seed stock -- grains, some fruit and lumber trees, a few herbs and ornamentals.