North American Fruit Explorers mailing list at ibiblio

[<dwoodard@becon.org>]

There is considerable overlap.
See
Plum breeding worldwide, Okie and Ramming 1999
<http://horttech.ashspublications.org/content/9/2/162.full.pdf>

[Crossing plum species], Okie 2006
<http://www.nyshs.org/pdf/fq/2006-Volume-14/Vol-14-No-1/Introgression-of-Prunus-Species-in-Plum.pdf>

Doug Woodard
St. Catharines, Ontario, Canada