What is a "strain"

[travis]

Originally Posted by Fusion_power

What is the difference between a glass half empty and a glass half full?

Nothing.

But I was thinking more that a breeding line would be stable to 99% or greater, and essentially beyond segregation except for the rare occurences of somatic or spontaneous mutations.

And I don't think of segregating expressions of purposeful crosses to be individual strains of a breeding line. For example NC 58S, NC 127 S, and NC 132 S, all of which are stable breeding lines developed by NCSU from Amelia F1. Should I consider the previously segregating lines of Amelia toward those three now stable breeding lines to have been strains on their way to being breeding lines?

I guess I thought a strain was stable, such as Platfoot Strain of Yellow Brandywine supposedly is a stable selection.