Identification of a locus conferring dominant resistance to maize rough dwarf disease in maize

Maize rough dwarf disease (MRDD) is a severe viral disease of maize that occurs worldwide, particularly in the summer maize-growing areas in China, resulting in yield losses and quality deterioration in susceptible maize varieties. An effective solution to control MRDD is to use resistance genes to improve the behavior of susceptible genotypes. Here, we employed maize F₂ populations derived from a cross between susceptible line S221 and resistant line K36 for the deep sequencing of the two DNA pools containing extremely resistant and susceptible F₂ individuals, and used traditional linkage analysis to locate the resistance-related genomic region. The results showed that MRDD resistance in K36 was controlled by a single dominant locus, and an associated region was identified within the genomic interval of 68,396,487 bp and 69,523,478 bp on chromosome 6. Two simple sequence repeat (SSR) markers 6F29R29 and 6F34R34 were tightly linked to the MRDD resistance locus. The findings of the present study improve our understanding of the inheritance patterns of MRDD resistance, and should inform MRDD-resistant maize breeding programs.