Development of a molecular marker for the Pi1 gene based on the association of the SNAP protocol with the touch-up gradient amplification method.

Genetic resistance is the most effective and eco-friendly approach to combat rice blast. The application of resistance genes may be facilitated by the availability of molecular markers that allow marker-assisted selection during the breeding process. The Pi1 gene, considered to be a broad-spectrum resistance gene, might contribute to enhancing resistance to rice blast, but it lacks a suitable marker that can be used. In this study, we investigated nucleotide polymorphism in the Pik locus and combined the SNAP protocol with the touch-up gradient amplification method to develop a SNAP marker. The Pi1 SNAP marker could distinguish Pi1 from Pik alleles, and when used for screening a germplasm bank and an F2 population, it consistently identified germplasms carrying the Pi1 gene. The P1 SNAP marker offers as advantages to involve only the presence/absence analysis of PCR amplicons resolved on an agarose gel.