Definition - What does Compatibility mean?
Compatibility is one of the four criteria for creating a successful graft of a scion on a rootstock. It is defined as having a sufficiently close taxonomic (genetic) relationship between the scion and the stock.
The limits of compatibility include the family, genus, species and clone. As the similarities grow further from the species, compatibility decreases.
WineFrog explains Compatibility
In order to have a successful graft union, the genetic compatibility of the scion and the rootstock is pertinent. It first helps that the two are of the same species. If that is not possible, then they must fall within the same genus or family.
However, further studies have been performed to evaluate three isoenzyme systems and the protein profiles among fifteen different grape cultivars and twelve American rootstocks. The compatibility between the rootstocks and the cultivars were determined by the similarities in their bands and their total protein profiles.
This information can help vineyard managers determine how successful a graft union may or may not be.