Effects of Recombinations on Variability and Heritability of Traits in Maize Populations with Exotic Germplasm

ABSTRACT

The following maize populations were encompassed by the study: a population with 25% of exotic germplasm (1601/5xZPL913)F₂R₀ and populations developed after three (1601/5xZPL913)F₂R₃, that is, five (1601/5 x ZPL913)F₂R₅ gene recombination cycles. The S₁ progeny trial was set up according to the nested design in two replications and two locations during two years (2001 and 2002). The average values for all traits except moisture at harvest increased. The changes of mean values of yields and other traits can be very important from the aspect of long-term breeding programmes. Different agroecological conditions, genotyp0e, family x location interaction and family x location interaction within the set significantly affected all observed traits of populations. Genetic and phenotypic variances for all traits except the 1000-kernel weight decreased under the effects of the number of recombination cycles, which was confirmed by the coefficients of heritability. A significant decrease was not detected in yields and ear lengths, which is particularly important for practical breeding. Three cycles of gene recombination are sufficient for this population prior to the application by various breeding methods.