seedstock

or seed stock

[seed-stok]
noun
  1. seed, tubers, or roots selected and kept for planting.
  2. animals, especially pedigreed livestock, maintained for breeding purposes.
  3. the animals needed to replenish a population, as after hunting or fishing.

Origin of seedstock

First recorded in 1925–30; seed + stock
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018