Maize is one of the world's most important crops, serving as the main source of food in many countries around the globe. According to FAO estimates, maize production reached 817 million tonnes last year, while rice and wheat yields reached 678 and 682 million tonnes respectively. This high productivity can be explained by the widespread use of hybrids worldwide. Their superior traits are due to the phenomenon of heterosis, which was first realised by Darwin and is used by breeders in their continuing efforts to improve crop plants. Hybrids have slowly replaced landraces and inbred lines in a country's germplasm. But the latter constitute an invaluable genetic resource that can be used to create new hybrids. The ways of assessing genetic diversity today vary, but the most widely used are those from the field of molecular biology. While studies using isoenzymes or RFLP markers are a thing of the past, they have the merit of having paved the way for marker-assisted breeding. New technologies, such as mass sequencing and microarray analysis, are providing a new perspective. In this context, we propose to use SSR and SNP markers to assess the existing genetic diversity in inbred maize lines in the country, define heterotic groups for them and then use the data thus obtained to compose a cross breeding scheme resulting in new hybrids with superior traits and increased productivity. We will analyse the heterosis effect in these new hybrids at three levels: molecular, biochemical and morphological. In addition to the immediately applicable results of our research, the data generated have potential in understanding the mechanisms underlying heterosis in plants.