Mapping resistance to Alternaria cucumerina in Cucumis melo

Infection with Alternaria cucumerina causes Alternaria leaf blight (ALB), a disease characterized by lesion formation on leaves, leading to substantial yield and quality losses in Cucumis melo (melon). While fungicides are effective against ALB, reduction in the frequency of application would be economically and environmentally beneficial. Resistant melon lines have been identified but the genetic basis of this resistance has not been determined. A saturated melon genetic map was constructed with markers developed through genotyping-by sequencing of an MR-1 (resistant) by Ananas Yokneum (susceptible Israeli cultivar) a recombinant inbred line (RIL) population (F6-F10; N=82) derived from single seed descent of a F2 population from a cross between the ALB resistant parent MR-1 and the ALB susceptible parent Ananas Yokneum. The population was evaluated for A. cucumerina resistance with an augmented block greenhouse study using inoculation with the wounded-leaf method. Multiple quantitative...