EXPECTED GENETIC ADVANCE FOR THOUSAND GRAIN WEIGHT AND GRAIN NUMBER PER SPIKE OF BREAD WHEAT AND DURUM WHEAT

The research was aimed at examining variability, variance components, broadsense heritability (h^2), expected genetic advance of thousand grain weight (TGW) and grain number per spike (GNS) of 15 genotypes of bread wheat and 15 genotypes of durum wheat. Field trials were carried out during 2010–2011 and 2011–2012 growing seasons at the three sites: Rimski Šančevi, Zemun Polje and Padinska Skela. Results of this investigation showed that the genetic component of variance (σ^2 g) was predominant for TGW of bread and durum wheat and for GNS of bread wheat. The genotype × environment interaction (σ^2 ge) component of phenotypic variance was 8.72 times higher than σ^2 g for GNS of durum wheat and pointed to the greater instability of durum wheat genotypes. H^2 was very high ( 90%) for TGW and GNS of bread wheat, high for TGW of durum wheat – 87.3% and low for GNS of durum wheat – 39.5%. Considering the high values obtained for h^2 – 96.4% and the highest value for expected genetic advance as percent of mean (GAM) – 19.3% for TGW of bread wheat, the success of selection for desired values of this yield component can be anticipated. The success of selection cannot be predicted for GNS of durum wheat due to low values obtained for h^2 and GAM of 39.5% and 2.8%, respectively.