THE GENETIC MAPPING OF XIPHINEMA INDEX RESISTANCE DERIVED FROM VITIS ARIZONICA
A breeding program to develop rootstocks with resistance to Xiphinema index, the dagger nematode vector of grapevine fanleaf virus (GFLV), has been underway for many years at UC Davis. A mapping population (0705) derived from 161-49C × R8916-22 was created in 2007 to develop an SSR-based linkage map for X. index resistance. 161-49C is a commercial rootstock susceptible to X. index feeding and R8916-22 is a heterozygous resistant cross originating from b40-14, a form of Vitis arizonica. Preliminary results suggest a 1:1 resistant:susceptible segregation ratio for X. index under greenhouse conditions. Previous studies showed that X. index resistance was controlled by a single homozygous locus. To date, 190 of 400 SSR markers were polymorphic, with coverage on all 19 linkage groups. These markers and others are being applied to the entire 0705 population to complete a genetic map of this excellent source of X. index resistance.
Van Zyl, S., Vivier, M.A., Riaz, S. and Walker, M.A. (2014). THE GENETIC MAPPING OF XIPHINEMA INDEX RESISTANCE DERIVED FROM VITIS ARIZONICA. Acta Hortic. 1046, 165-168
SSR markers, QTL, linkage groups, polymorphic markers