Evaluation of maize (Zea mays L) inbred lines for yield component traits and kernel morphology

The economical production of the seed of any hybrid maize (Zea mays L) variety is dependent on the parental characteristics of the inbred line used as the seed parent. Grain yield, thousand-kernel weight, ear length and kernel morphology are traits that are important in determining the suitability of an inbred line for use as a seed parent in a seed production field. In 2009, replicated field trials at Janesville, WI and Stanton, MN included 27 maize inbred lines obtained from the North Central Regional Plant Introduction Station in Ames, IA. Inbred line evaluations included measurements of grain yield, thousand-kernel weight, and ear length. Separation of the harvested seed into the different size classifications based on kernel morphology allowed further characterization of inbred lines. Significant differences existed among inbred lines for grain yield, thousand-kernel weight, ear length and kernel morphology. Among this group of inbred lines, ear length appeared to make a greater contribution to grain yield than thousand-kernel weight. Correlation analysis indicated that a strong negative relationship exists between kernel morphology types classified as “large rounds” and “medium flats”, with the latter group being the more desirable of the two. The results of this study suggest that plant breeders may want to consider evaluating inbred parents for their kernel morphology before beginning a breeding project or before selecting an inbred to serve as the seed parent in a production field