Revista Brasileira de Milho e Sorgo (Aug 2007)
POPCORN INTRAPOPULATION RECURRENT BREEDING WITH HALF-SIB FAMILIES
Abstract
Half-sib selection is the most common corn breeding procedure. As theinformation about efficiency of this method is generally based on predicted gains, the objective of this paper is to discuss its efficiency considering realized gains. The base population, named Beija-Flor, is of the popcorn type. The analyses considered the progeny tests of the four first cycles of half-sib selection and four other trials, with improved populations and checks. The first three cycles, with among family selection based on index with expansion volume (EV) and yield, and within progeny selection based on EV, determined improvement in EV and yield, but the genotypic variability was reduced. In relation to EV and yield, the average of the realized gains per cycle were 5.6% (5.5%, 5.4% and 5.9%) and 8.1% (– 11.3%, 67% and – 31.5%), respectively. The correlated responses relative to traits not considered in the selective process were, as expected based on predicted gains, of reduced magnitude.
