GENETIC-BASIS OF RESISTANCE IN MAIZE TO 5 MAIZE-DWARF MOSAIC-VIRUS STRAINS

Maize dwarf mosaic (MDM) is a widespread viral disease of maize (Zea mays L.) in the souther U.S. Corn Belt. An understanding of the genetics for resistance to maize dwarf mosaic virus (MDMV) will provide a rational basis for effective selection. Our objective was to determine the genetic basis of resistance in inbred Pa405 to Strains A, B, D, E, and F of MDMV by examining the association between host symptom responses, and chromosomal translocation and morphological or molecular markers. Twenty-six translocation markers and the morphological marker y1 were incorporated into inbred M14. Linkage relationships with molecular markers were determined by restriction fragment length polymorphism (RFLP) analysis, using molecular markers UMC85, BNL6.29, UMC59, and UMC21. The three approaches all indicated a gene or genes on either the short arm or the proximal region of the long arm (proximal to Y1) of Chromosome 6 in inbred Pa405 controlling resistance to all five strains of MDMV.