There are named forms (raised by division), as well as seed strains.

But the Pentagon refused to share the seed strain for its program with the civilian program.

But this loss, he argues, is almost certain to be overwhelmed by a century's worth of improvements in seed strains and growing techniques.

The use of better fertilizers and seed strains became widespread.

Almost all the variations and hybrids retain that primrose charm, only the modern F1 seed strains have lost their elegance in the foolish search for larger and more garish flowers.

Because the antigenicities of the wild viruses evolve, vaccines are reformulated annually by updating the seed strains.

However, when the antigenicities of the seed strains and wild viruses do not match, vaccines fail to protect the vaccinees.

New crops, new seed strains and new rotations were introduced.

The Jack Herer Cannabis hybrid was created in 1994 by the Sensi Seed Bank in the Netherlands and was released as a seed strain in 1995.

Oh, and you've got to buy the right seed strain.