Partial diallel analysis between maize inbred lines

Resumo

Diallels in maize provide the knowledge of genetic parameters of lines and heterotic groups used. In this study, the general combining ability and specific combining ability, GCA and SCA respectively, were estimated in a partial diallel cross between maize inbred lines in five crop environments. In the 2011/2012 crop, some important agronomic characteristics were evaluated in five environments of southern Brazil. The difference of hybrids and environments was significant for all characters, however, the hybrid x environment interaction was significant only for plant height (PH) and grain yield (GY). GCA effects for the two heterotic groups and SCA effects were significant for all characters when hybrids were evaluated by the average of environments. Only for PH and GY the SCA x environment interaction was significant. The heterotic group I (female), arising from commercial single hybrids with high grain yield, showed interaction only between GCA x environment for PH, indicating predominance of additivity for the other characters in these lines, which do not vary according to different environment conditions. In most cases, hybrids with the best SCA values are not obtained from lines with the best GCA values.