Which preposition to use with rootstock

of Occurrences 2%

Asplenium Ruta-muraria Rootstock of Lady Fern (Two parts) Sori of Lady Fern.

after Occurrences 1%

As the jointed stipes, harking back to some ancient mode of fern growth, fall away from the rootstocks after their year of greenness, they leave behind a scar as in Solomon's seal.

as Occurrences 1%

The young ferns should be transplanted in early spring with as much of the long, running rootstock as possible.

Which preposition to use with  rootstock