Genetic diversity of maize lines for traits related to maturity and yield components

Abstract

Grain yield and maturity class are among the commercial traits that most often direct maize breeding that aims to meet the requirements of the seed market. Thus, the aim of this study was to evaluate genetic diversity in maize inbred lines for grain maturity and yield components. The phenotypic attributes of 81 maize inbred lines were assessed in a field experiment in a square lattice design with three replications. Analysis of variance and multivariate analysis were performed considering complete randomized blocks due to the equivalence to the estimation for lattice efficiency. The results of analysis of variance indicated genetic diversity in the germplasm for all the traits, showing high variability for number of days to male flowering (DMF) and female flowering (DFF). Genetic diversity was also detected for grain water loss, which was determined by the area under the water loss curve (AUWLC), an index representing the dynamic progress of field water loss, based on area under the disease progress curve (AUDPC). The high magnitude of genetic correlation between the AUWLC and the moisture content of grain (0.98) collected at different moments in the R6 stage suggests the possibility of its substitution by the moisture content evaluation in only one collection. Weak genetic correlations (0.07 to 0.45) between yield and maturity components indicated the possibility of selection for earliness without compromising yield. In addition, the results of the Tocher method and the UPGMA were compatible, enabling classification of the germplasm and suggestion of hybrid combinations among inbreds that might have a higher heterotic effect on yield associated with earliness.