Quantitative trait analysis of resistance to plum pox virus in the apricot F1 progeny “Harlayne” × “Vestar”

Plum pox virus (PPV) is a devastating stone fruit disease of major importance, and better understanding of the genetic control of resistance to this trait would be useful for more efficient development of resistant cultivars. Previous studies have reported a locus of major effect from PPV resistance on linkage group 1. The current study confirms these results by mapping plum pox virus resistance in a F1 progeny issued from a cross between “Harlayne”, as a PPV-resistant parent, and “Vestar” as a susceptible parent. The hybrids were grafted simultaneously and subsequently inoculated with the PPV-M and D strains. The symptom scoring on leaves was performed nine times over two vegetative cycles. Marker-trait associations were analyzed using the Kruskal-Wallis (KW) non-parametric test, and the PPV resistance loci were mapped using composite interval mapping (CIM). We show that both analyses (KW and CIM) highlighted the upper part of linkage group 1 of the apricot “Harlayne” genitor.