Last year I was given 1 cutting of Brogiotto Nero by a generous friend sharing theirs. I encountered a fast rooting followeed by months of the small tree barely making it. All the leaves came out deformed as is so common with FMV. Late summer it shot up to about 4 feet that was all wood growth with a plume of deformed leaves on the top. 

I decided to air layer it before winter so if it finally kicked the bucket I might have one left. I got a decent 20" airlay done and into a 1 gallon pot before winter and stuck the layer in the garage. It is finally breaking bud and the leaves on the air layer are showing no visable signs of the virus but the mother tree is still showing it.

While I know they have to both have it I was wondering if any of you have had simular experience with an air layer looking better?

some times, even on same tree one branch will show the issue and other won't. the Calvert that i'm keeping had small side branch that was showing severe problem. so i cut that off and kept the other branch.

the branch i kept looks good this yr. most of other Calverts are looking good too. decide to give them away.

My VdB from UCD was so ugly and deformed I planted in the ground, the top all died back and then it shot our suckers huge and healthy, then one of the dogs chewed it up so it's no more.  My thought is you get some growth that has a better immune system than the rest and a means to survive like a sport but not a mutation, just a healthy version of the plant.

The cutting may be less stressed than the original plant had been. I think a lot of people find that when the trees are stressed deformed leaves are more numerous and pronounced. Both trees should have the virus, as it would be passed down through the propagation process. Rooting cuttings is asexual reproduction - essentially cloning. There is the possibility of a mutation from UV rays or other environmental factors that may slightly alter the DNA of the plant, but it is unlikely.

Hi,
What you thought was fmv was perhaps a sign of bad feeding to the tree.
I saw at a nursery late august a small fig tree with leaves patterned as some photos I saw about fmv - the tree was stressed and lacking nutrients and water - It had been like that for weeks.
It was a brunswick and although I've been chasing for it, I left it at the nursery - the tree was not worth the risk - one never knowns ...
So basically, you perhaps just fed more properly the tree afterwards and thus the tree got in better shape.
Keep on feeding her well with fertilizer and/or manure.

As for cuttings, the cloning technique is not perfect and you can still find cuttings with differences when compared to the mother plant.
I have a test running about an 1,5 meters of height tree that died back to the ground but the roots died as well .
She came back at 1cm above ground - she has done an auto-airlayer of the only cells that resisted the 2012 cold spell .
That small tree is for now a shy grower. She should bear fruits this year - that will help me to see more of what got mutated in that tree .

The tree got the same nutrients and water as the rest and it is without a doubt FMV. That being said I think that stress may absolutely be a factor fig tree. The original was started as a cutting last year.

It can't be the different branch theory because it is the same branch just air layered in two. All I know for sure is, I'm really happy the air layer wants to look good while it's growing :)

I've experienced the same as Pete on my Verdal Longue.  Some limbs are stunted with deformed leaves while others are vigorous and healthy... This even happens with two limbs at the same fork in a branch.  The difference can be very dramatic.