Genetic parameters estimates in the maize variety BR 5028-São Francisco in the Brazilian Northeast region

Abstract

The objective of this work was to obtain genetic parameters estimates in the maize variety BR 5028-São Francisco, submitted to 13 selection cycles among and within half sib families, in Sergipe and Bahia states. The additive genetic variance estimates reduced after the first three selection cycles with a drastic reduction from cycle I to cycle II due to moisture stress. The expected mean gain when the selection was done in one environment, by selection cycle, during the first three cycles was 10.6%. In the selection cycles VI and VII, the genetic variability was stable. In cycle VIII an increase of variability was observed and then, stabilized between cycles IX and XV, when the selection was done in more than one environment. The expected and obtained mean gain (cycle/year) between cycles VI and XV were 20.0% and 4.03%, respectively. The obtained values of the genetic parameters estimates justify the continuity of maize breeding program to increase the production.