SNP5044 polar cluster plot. A) Genotype plot created by GeneMapper software v. 4.0 (ABI). The software analyzes the electropherogram and uses a clustering algorithm to assign the correct genotypes. SNP genotypes are displayed as a polar plot in which the intensity of the peaks is measured on the x axis and the ratio of both peak heights is measured on the y axis. B) Sequences flanking the target SNP5044 in Syrah (sy, bottom), Pinot Noir (pn, center) and one progeny (I49, top). The red asterisk indicates the unexpected additional polymorphism in Syrah and I49 near the target SNP represented by dark asterisk. The presence of the unexpected polymorphism explains the artificial homozygous cluster (C*T) shown in part A.