Genetic and phenotypic variability of yield components in wheat (Triticum aestivum L.)

Variability, heritability and components of variance for number of grains per spike and grain weight per spike have been studied in 10 winter wheat varieties from different selection centers (Arsenal, KG-56, Gruza, Mironovskaya 808, Norin 10, Rana Niska, Spartanka, Sterna, Osjecanka, and Szegedi 765). The experiment was performed in randomized block design in three replications on the experimental field of Small Grains Research Centre, Kragujevac in three years. Average estimated values for number of grains per spike and grain weight per spike differed significantly among years and among varieties. The highest average value for number of grains per spike had Szegedi 765 variety ( x = 75.1) and the lowest value was found in Spartanka ( x = 56.0). During investigated period the highest average value for grain weight per spike was determined in Gruza ( Norin 10 ( x = 2.9 g), and the lowest value in x = 2.0 g). The average variation coefficient for number of grains per spike was 17.4%, and for grain weight per spike was 21.4%. The lowest variability for number of grains per spike and grain weight per spike was established in Sterna variety (V = 13.0%; 16.2%, respectively) and the highest in Norin 10 variety (V = 21.6%; 25.1%, respectively). Obtained heritability value in broad sense for number of grains per spike was about 60%, and for grain weight per spike about 40%. Statistical analysis of variance established highly significant differences in mean values for number of grains per spike and grain weight per spike. Phenotypic analysis of variance indicated that ecological factors had higher impact on the expression of number of grains per spike and grain weight per spike than genetic factors