Relationships between Stalk Resistance and Corn Borers, Agronomic Traits, and Cell Wall Hydroxycinnamates in a Set of Recombinant Inbred Lines from a Maize MAGIC Population

Abstract

Corn borers are the most important pest affecting maize. Resistance to corn borer attack may compromise plant fitness being detrimental for some important agronomic traits such as yield. Against the attack of this pest, cell wall-bound hydroxycinnamates have been previously described as a possible defense mechanism. In this study, agronomic characterization and cell wall-bound hydroxycinnamates quantification was performed in a subset of Recombinant Inbred Lines (RILs) from a Multiparent Advanced Generation Intercross (MAGIC) population that showed contrasting behavior against corn borer attack. Resistant lines showed greater concentration of p-coumaric acid, the only hydroxycinnamate that could have a role in the resistance in these particular materials. In addition, results indicated that resistant lines showed precocity, low grain moisture at harvest, and reduced plant height, thus, selecting for resistance may be detrimental for yield. In this way, a breeding strategy directly targeting grain yield in order to tolerate corn borer attack would be the recommended one.