I and others have been experimenting with Amelanchier for pear rootstock.
It is very dwarfing and quite precoscious. It isn't perfect however as
another grower has found that you should leave a shoot of amelanchier to
grow as well as the pear scion as the rootstock just isn't that happy to
have a pear on it. My own grafts just sat there for two years before
finally showing some vigor this year.
I believe it has been used by Dr. Olmo in the Pacific NW as well, with good
results however, although I am not sure if the amelanchier was a local
species or not.
I am doing breeding between my local amelanchier and pyrus ussuriensis to
hopefully come up with a rootstock that is more accepting of the pear scion,
and still dwarfing. One thing is certain, the rootstock is rock solid
hardy.
Take care,
Dean Kreutzer
Regina, Saskatchewan Canada
USDA zone 3