Lab-Grown Esrogim

I was wondering:

Would posqim who say that lab-grown meat is no more kosher or pareve than
the cells it was cultured from say the same about esrogim? Would they
consider a lab-grown esrog to be kosher?

There is another wrinkle -- murkav. An esrog branch grafted on a lemon
tree will grow murkavim even though there is no genetic impact on the
citrons.

So, for example, I would be surprised if an esrog cloned by putting esrog
DNA into a lemon pit that had all the lemon DNA scrubbed would be kosher.
The pit seems too much like a lemon tree's trunk.

But what about a straight lab-grown esrog, let's say the matrix it is
grown on would be no more alive than dirt.

Tir'u baTov!
-Micha