Combining Ability for Nitrogen Use in a Selected set of Inbred Lines from a Tropical Maize Population

Abstract

Tolerance rather than resistance, is the crop response mechanism sought by maize breeders for cultivation under low levels of nitrogen. Although improved nitrogen use is in intensive research by maize breeders, little is known about its inheritance on tropical maize germplasm. The objectives of this study were to evaluate the N use through yield and other traits, and to determine the importance of general (GCA) and specific (SCA) combining ability effects in the inheritance of N use, for yield, using a diallel of crosses among a selected set of tropical maize lines under two levels of N.