Identification of Single Nucleotide Polymorphism Markers Associated with Northern Corn Leaf Blight Resistance in Sweet Corn

Abstract

Northern corn leaf blight disease (NCLB) is a foliar disease of corn (Zea mays L.) caused by Exserohilum turcicum (Pass.). The Ht1, Ht2 and HtN1 genes in corn were found to control NCLB resistant traits. There has been an ongoing effort to identify various types of molecular markers associated with these genes in order to use them in marker-assisted selections. The objective of this study was to identify Single Nucleotide Polymorphism (SNP) markers which are associated with the Ht1 resistant gene. Ninety-three SNP markers were found in Ht1 regions, which are located on chromosome 2. Five SNP primers (MZSNP-0055106, MZSNP-0065744, MZSNP-0070164, MZSNP0063922, MZSNP-0073150) showed polymorphism between susceptible and resistant lines. The Chi-square test of genotypic data of 184 F2 plants (NT58WS6#4 x ChallengerS6-1) amplified by five markers fit a 1:2:1 ratio with Chi-square values of 0.82, 1.08, 1.08, 0.64 and 0.64 respectively. These 5 SNP primers may be useful as molecular markers for NCLB resistance in sweet corn.