Identification of RAPD markers tightly linked to the dwarf mosaic virus resistance gene in maize

Random amplified polymorphic DNA (RAPD) based on the polymerase chain reaction (PCR) was adapted for molecular marker applications in maize. The objective of this study was to identify RAPD markers linked to maize dwarf mosaic virus (MDMV) resistance genes using segregation analysis. Genetic segregation of all polymorphic markers tested in F ₃ progeny fit the expected 3:1 Mendelian ratio, 436 random UBC primers were screened for the amplification of polymorphic DNA fragments on two pools of genomic DNA isolated from plants that were homozygous for resistance or susceptibility to the MDMV. Four RAPD markers were mapped within 25cM in the region containing the target gene. The 650bp fragment amplified by primer UBC376 was tightly linked in coupling to the MDMV gene. Based on these results it is concluded that RAPD markers can be a valuable tool for maize breeding and useful for indirect selection for traits difficult to score like maize virus diseases.