Observations of graft compatibility between Citrus spp and related Aurantioideae taxa

Although Citrus has long been known to be graft compatible with the genus Poncirus, compatibility betweenCitrus and other genera of the Aurantioideae is less well characterized. Graft compatibility between Aurantioideae genera has historically been associated with the use of the related taxa as rootstocks for Citrusspp. However, the use of Citrus spp as rootstocks for related taxa can be useful in maintaining germplasmaccessions, in propagating specimen trees or specific commercial taxa, and biological indexing in a sanitationprogram. One of the largest collections of taxa related to Citrus is maintained by the University of Californiaand the United States Department of Agriculture in Riverside, California. This paper reviews historicalobservations made in Riverside of graft compatibility between Aurantioideae genera and updates them withcurrent observations. Specific combinations have been observed to be incompatible whereas others haveshown either short- or long-term compatibility and survival.