Heterotic Patterns among Algerian, US Corn Belt, and European Flint Maize Populations under the Mediterranean Conditions of North Africa

Algerian maize (Zea mays L.) landraces could play an important role in improving commercial maize hybrids under stress conditions. To study this, we identified heterotic patterns by crossing six Algerian maize populations from a collection of accessions (defined by germplasm accession codes) that represent Saharan maize in a diallel design without reciprocals. Furthermore, to define heterotic relationships among Algerian germplasm and previous heterotic groups, these populations were crossed, following the North Carolina II (NCII) mating design, with two representatives of the heterotic pattern north Spain x south Spain (European flint) and with one population from US Corn Belt dent. The populations per se, their respective crosses, and checks were evaluated in Algiers, Algeria, in 2015 and 2016. Highly significant varietal effects for early vigor, reducing flowering time, and increasing yield production were observed among Algerian maize populations. Among Algerian crosses, AOR x IZM presented significant and positive specific heterosis for early vigor, whereas AOR x IGS and IZM x MST were the most outstanding crosses for yield. Concerning the NCII, AS3(HT) C3 x IZM had the highest performance for early vigor and yield, followed by EPS13(FR)C3 x BAH, EPS14(FR)C3 x MST, and AS3(HT)C3 x SHH. We found a high degree of genetic divergence among Algerian maize populations and between Algerian maize populations and Corn Belt dent and European flint germplasm from northern and southern Spain. These populations, particularly AOR, IGS, and IZM, could be used for intrapopulation and/or interpopulation selection, or for further inbred line development.