My point being ... if you have 20 Black Ischia trees with the same genetic makeup, and they are infected by FMV, one of them is not going to be "worse" because it is "more heavily" infected. If it's infected, it's infected. The virus is there. It's not like some trees have "twice as much" virus inside them, therefore they are "worse off". They're either infected or they're not.
If they are genetically the same plant material, they should be affected by FMV in the same way, to the same degree, and FMV should distribute amongst the cells of the plant to a similar fashion. It shouldn't be possible for two genetically identical plants (taken from cuttings of the same tree) to be more or less affected, if you follow me.
Or maybe I'm just crazy.
I think the "more affected" plants are probably infected with more than just FMV, and the presence of two different viruses allows for one of the two viruses to more heavily affect the plant.
PS - Martin, I will email. You have PMs turned off.