Genetic Control of Maize Hybrid Performance Using Complex Pedigrees and Microsatellite Markers.

The purpose of this study was to determine the importance of epistatic effects on maize heterosis by means of a single model, based on analyses of di-, tri- and tetrallelic and also with the information from microsatellite markers. For that reason, 51 lines from different backgrounds were used, thus obtaining 6 double hybrids, 14 three-way hybrids and 58 single hybrids, for a total of 78 hybrids. Seventy-nine microsatellite markers were used in the genotyping of the 51 lines. These markers are distributed along the 10 maize linkage groups. This information was used in construction of the relationship information matrix. According to this study, it was possible to break down heterosis and better understand the participation of epistatic effects in it when jointly analyzing single, double and three-way hybrids under the same model. Under this approach, it is possible to understand heterosis in its diverse components. It was also possible to verify that with the use of molecular markers there was a trend toward improvement of the accuracy of the epistatic and dominance genetic effects. Thus, with the computational resources currently available, advanced statistical techniques and use of molecular markers, it is possible to better understand heterosis and the factors that control it.