MAP BASED IDENTIFICATION AND POSITIONAL CLONING OF XYLELLA FASTIDIOSA RESISTANCE GENES FROM KNOWN SOURCES OF PIERCES DISEASE RESISTANCE IN GRAPE

• Author(s): Riaz, Summaira; Walker, Andrew;
• Abstract: Development of an SSR genetic linkage map based on the 9621 family is continuing. The family segregates for PD resistance and is based on the cross of PD resistant D8909-15 x PD resistant F8909-17. We expanded the mapping population size from 116 to 188 genotypes. The current genetic linkage map consists of 217 non-AFLP markers (SSR, ESTSSR and ESTP) in 19 linkage groups. The PD resistance locus PdR1 maps to linkage group 14 of the male parent (F8909- 17), which now consists of 30 markers, 9 of which are localized within 10 cM of PdR1. To avoid confounding affects from resistance inherited from D8909-15 additional families derived from a susceptible by resistant cross are currently being evaluated for map based cloning of the PdR1 locus. A family from the cross of F2-7 (a cross of two V. vinifera wine grapes, Cabernet Sauvignon x Carignane) x F8909-08 (a PD resistant sibling of F8909-17) has been made and is currently being screened for PD resistance via our standard greenhouse testing procedure. To saturate a narrow region around the resistance locus with molecular markers, bulk segregant analysis (BSA) in concert with the AFLP marker system has been initiated in cooperation with our report titled Optimizing marker-assisted selection (MAS) for resistance to Xylella fastidiosa to accelerate breeding of PD resistant grapes.
• Publication Date: Dec 2004
• Journal: 2004 Pierce's Disease Research Symposium