Potential of Grain Physical Traits to the Study of Variability in Maize

Aims: The identification of new traits that can be used as phenotypic markers as well as potential indirect selection tools is interesting for plant breeding. The objective of the study was to investigate the potential use of physical traits of grains to study phenotypic variability in maize.

Methodology: Ten maize varieties were evaluated, one commercial variety and nine local open-pollinated varieties. After harvesting, the following traits were evaluated: mass of 1000 grains, weight of ears, grain yield per hectare, estimated from plot production; real volume and apparent volume; real density and apparent density; sphericity and volumetric weight; obtained in samples of 50 grains of each of the studied varieties. A principal component analysis was performed on the data. First, those traits that showed a strong correlation with components capable of explaining a smaller portion of the total variation were excluded from the analysis. A new principal component analysis was performed with the remaining traits.

Results: The result revealed the possibility of excluding five of the ten analyzed variables: mass of 1000 grains, weight of ears, apparent volume, real density, and volumetric weight. Some possibilities of trait exclusion can be explained by correlation and method of estimate among them. The genotypes G2 and G3 showed great difference, mainly due the grain yield. The porosity and real volume contributed to the majority variation among genotypes.

Conclusion: Some physical grain traits showed potential for use in divergence studies. Apparent density can be used in indirect selection strategies for higher grain yield.