Genetic, phenotypic and environmental correlations in two cicles of selection in the "Dentado Composto" corn

Abstract

The objective of this study was to determine the genetic, phenotypic and environmental correlation coefficients among the following traits: plant height (PH), ear height (EH), ear number per plant (EN), ear number with husk problems (ENHP), Spodoptera frugiperda damage (SF), Heliothis zea damage (HZ) and grain yield (GY). Data were collected from two cycles of selection among and within hal-sib families in "Dentado Composto" corn, assessing SF and HZ damages and high grain yield. Natural infestation of these insect pests was considered. The experiments were conducted in the experimental field of IPA. No correlation was observed between PH and SF nor between EH and HZ. The GY character was negatively correlated with HZ and SF; however in the first cycle, the genetic correlation between GY x SF was positive and lower (r = 0,027**). The character SF showed negative and significative genetic correlations with HZ; this association was lower in the second cycle. There was an increase in the number of genetic correlations higher than the environmental in the second cycle.