Re: Virus clean-up

Loren Russell (loren@PEAK.ORG)
Sun, 18 Feb 1996 16:16:49 -0800 (PST)

Concerning viral transmission and seeds: I certainly can't claim
that NO viruses are transmitted through seed, but it would be
exceptional! It's a general rule throughout plants and animals that
germplasm has an effective "firewall" to vertical transmission of
pathogens. Considering the ubiquity of pathogens and vectors, little
would survive otherwise. As a practical matter, propagation by seed does
"clean up" strains in other plant groups subject to viruses, and I'd
expect it to work in CPs.

Vertical transmission of viruses is known, at least in insects,
but it's associated with "latent" viruses which may be asymptomatic for
generations. Virulent strains that are also vertically transmitted would
go extinct with their hosts.

The mention of "rapidly growing tissue" being virus-free was
intended to illustrate why Tissue Culture can also work. Not especially
a recommendation for the home gardener.

Loren Russell, Corvallis, OR