Cardinal grape parentage: a case of a breeding mistake.

The grapevine (Vitis vinifera L.) is one of the most widely grown fruit plant, with table grapes accounting for at least 20% of the total world production. A few traditional table grape cultivars have achieved great international prominence. Among the most important cultivars is ‘Cardinal’, an historical Californian grapevine obtained by E. Snyder and F. Harmon in 1939 by crossing ‘Flame Tokay’ (syn. ‘Ahmer Bou Amer’) with ‘Ribier’ (syn. ‘Alphonse Lavallée’) at the Horticultural Field Station of Fresno, Calif.. In the course of DNA-typing of grapevine varieties collected in Algeria and in other Mediterranean countries, we found, surprisingly, that ‘Cardinal’ could not result from this cross. Here, we present molecular genetic evidence that ‘Cardinal’ has no parentage relationship with ‘Flame Tokay’. We also show, for the first time, that ‘Flame Tokay’ is a mutant version, at the VVs5 microsatellite locus, of the table grape ‘Ahmer Bou Amer’, which is considered its synonym.