Establishing Genetic Relation between a Marker Locus and Fungal Disease in Grapevine Using Multidimensional Scaling Analysis

Abstract

In a hybrid population of ‘Italia’ (female) and ‘Mercan’ (male) grape cultivars with their 60 offsprings, a classical two-point linkage analysis was attempted with 300 RAPD, 20 SSR and 24 AFLP primers using Mapmaker/Exp 3.0. Linkage groups of 12 in ‘Italia’ and 4 in ‘Mercan’ were attained with 25 and 8 marker loci, respectively. Resistance phenotypes and segregating characteristics were scored as quantitative traits in two growing seasons. MDS analysis was performed to examine the relationship between the marker loci and the fungal diseases, powdery and downy mildew, both of which developed naturally on the progenies. Results of the MDS showed that five and eight marker loci were in close relationship with the powdery and downy mildew, respectively. The R2 was 62.12%, which considered as acceptable fit and the stress coefficient was 0.26.