Four-Parent Maize (FPM) Population: Development and Phenotypic Characterization

To measure the effectiveness of multiparent population design in maize (Zea mays L.), an unprecedented, four-parent maize (FPM) population was developed, incorporating a series of different mating designs. The FPM population incorporated up to three generations of intermating to allow for comparison of traditional biparental, multiparent, and multiparent intermated populations for phenotypic diversity. A total of 1291 inbred lines were evaluated per se with at least one replication among 5551 total progeny plots across two inbred trials 2013 and three inbred trials in 2014 at College Station, TX. These trials were phenotyped for days to anthesis and silking, plant and ear height, leaf rolling, and cob and kernel color (yellow endosperm, blue aleurone). Significant genetic variation was found for all traits analyzed, as well as substantial environmental variation for days to anthesis and days to silking. Overall, single replications of population entries performed well for agronomic trait analysis as indicated by low residual variation. Although mean flowering time did not show a particular relationship to specific subpopulations, greater variance was observed for plant height in some of the FPM populations than in the biparental populations. The creation of this population and the analysis of these traits serve to showcase the advantages and disadvantages of traditional and complex mating designs and reveal the potential to research agronomic and other traits within this population resource.