Use of Heterosis in Maize Breeding: History, Methods and Perspectives – A Review

Abstract

The hybrid vigor is one of the greatest practical contribution of genetics to the agricultural world and had its most significant expression in maize crops, being intensively explored by breeders and seed production companies. This review presents aspects of the genetic basis for heterosis, biometrical assessment, and improvement methods to obtain heterotic hybrids and reciprocal recurrent selection in maize. Contributions from Biotechnology and Molecular Genetics as tools for hybrid programs to diminish hand pollination work to obtain inbred lines and to form heterotic groups through molecular markers are also reported. Finally, the identification of QTLs to help select superior lines and confirm genetic hypotheses is presented to completely elucidate the heterosis phenomena