Integrating Genomics and Metabolomics to Inform Breeding for Powdery Mildew Resistance in Grapevine

Abstract

Two powdery mildew resistance loci have been identified using pedigree-connected F1 mapping families at the University of Minnesota grape breeding program. A consensus linkage map of the resistant parent (MN1264) was developed for genetic mapping. The resistance loci were mapped on chromosomes 2 and 15, with additive effects accounting for over 30% phenotypic variation. Marker haplotypes, hap+chr2 and hap+chr15, were constructed to trace the inheritance of resistance loci in grandparent-parent-progeny relationships. Both hap+chr2 and hap+chr15 in the resistant F1 progeny were inherited from parent MN1264, that originated from grandparent ‘Seyval blanc’. Additionally, two microsatellites markers (i.e., UDV-015b and VViv67) were identified to be associated with hap+chr15, and can be applied for marker-assisted selection. In a follow-up study to characterize metabolic changes attributed to hap+chr2 and hap+chr15, a metabolomic experiment was conducted on whole-plant propagated grapes in a time-course response to in vivo inoculation. The use of several multivariate analyses systematically identified 52 biomarkers that were associated with hap+chr2, and 12 biomarkers with hap+chr15. In a temporal assessment of biomarkers, the discriminating metabolic changes distinguishing resistant and susceptible individuals appeared to be occurring from 24 to 48 hours after inoculation.