PAPER TITLE :INFLUENCE OF POPULATION SIZE ON ESTIMATES OF GENETIC VARIANCES, HERITABILITY AND PREDICTED GAINS IN TWO TROPICAL MAIZE POPULATIONS

APPLIED TROPICAL AGRICULTURE | VOLUME 23 NUMBER 2 2018

Paper Details

  • Author(s) : Oloyede-Kamiyo Q.O.*
  • Abstract:

The cost of evaluating large sample size is a limitation in population improvement programme. A study was
conducted in Ibadan and Ikenneto assess the influence of population size on estimates of genetic variability and
predicted gains in two maize populations. Four population sizes tagged P-250, P-200, P-150 and P-100 were
generated from each of the two maize populations using NCII mating scheme. The experiment was laid out in a
randomized incomplete block design in two replications. Data were collected on agronomic and yield traits. Genetic
parameters and narrow-sense heritability were estimated from combined analysis of variance. The type of gene
action controlling each trait is consistent in all the population sizes although values were higher in other population
size compared to P-250 for most of the traits studied. Means, heritability estimates and predicted gains were higher
in P-200 and P-150 compared to P-250 especially for yield and yield traits. Estimates of heritability and gains were
also high in P-100 but this was not consistent especially for yield traits. Considering the cost of evaluating large
number of samples in population improvement programme, sample size of only 150 could be used without
compromisingvariability and genetic progress.
Keywords: Heritability; Maize (Zea mays); Population size; Predicted gains; Recurrent selection
Running title: Genetic gains as influenced by population size in maize.