I should mention to general readers that I always assume that most all of my lilies carry one virus and that many of my older established ones may even carry two viruses. It's the third additional and unsuspected virus that I'm concerned about. A lily can carry a virus and not show it in any way and even with two they may perform pretty good but add a third and you're in real trouble. Plants are just like people, catch a cold and you can still work and look OK, Add in the flu and pnuemonia you'll feel and look tough. Now add in Cancer brought on by that bodily stress and you're real trouble. So, weakened lily bulbs caused by viruses often succumbed to things like bulb rot, etc. Weakened lily plants (the cultivar) still can be saved through seed however, since the seed will not carry the virus(s) but then we call it a strain of the parent cultivar.
Edit Note Added March, 25th. My usage of the word 'strain' above in such a broad sense is somewhat misleading
and technically speaking, inaccurate. For a more precise difinition of 'strain', please refer to Leftwood's post of 3/24/13 and susequent posts that follow it
located in the 'sticky' Thread: Hybridizing Lilies, for a more thorough understanding.
