Identification of Molecular Markers for Barley Yellow Dwarf Virus Resistance in Maize By Genome Wide Association Study

With increasing winter temperatures in Europe, barley yellow dwarf virus (BYDV) is expected to become a prominent problem in maize cultivation. Breeding for resistance is the best alternative to control the disease and break the transmission cycle of the virus. The objectives of our study were (I) to determine genetic variation with respect to BYDV resistance in a broad germplasm set, (ii) to identify genes which are involved in the BYDV resistance mechanism and (iii) to provide markers for selection on BYDV resistance.

An association mapping population with 267 genotypes representing the worlds maize population was grown in the greenhouse. Plants were inoculated with the virus BYDV-PAV transmitted by aphids of the species Rhopalusiphum padi.

In the association mapping population we observed considerable genotypic variance for the trait virus content as measured by DAS-ELISA (double antibody sandwich enzyme-linked immunosorbent assay) and the infection rate. In a genome wide association study we observed significantly (FDR=0.05) associated SNPs with the BYDV resistance in 3 genes. The functions of these genes were linked to virus resistance mechanisms.

The SNPs, significantly associated with BYDV can be used in marker assisted selection and will accelerate the breeding process for the development of BYDV resistant maize inbreds.