Components of genetic variability and heritability of the number of rows per ear in silage maize

Abstract

The aim of this study was to estimate the following components for the number of rows per ear in silage maize: variability of inbred lines and their diallel hybrids, superior-parent heterosis and components of genetic variability and heritability on the basis of diallel hybrids. It was determined that the variability of this trait was significantly affected by a genotype, year and their interaction. Inbred lines ZPLB 402, ZPLB 403 and ZPLB 405 had a higher number of rows per ears than majority of hybrids in both years of investigation, which resulted in negative values of heterosis. The analysis of components of genetic variance indicates that the additive component (D) was higher that the dominant (Hi and H2) genetic variance while a positive value of the component F and frequency of dominant (u) and recessive (v) genes for the observed trait point out that dominant genes prevailed over recessive ones. Furthermore, this is confirmed by a dominant to recessive genes ratio in parental genotypes for the number of rows per ear (Kd/Kr>l) in both years. The evaluated average degree of dominance a/h^7d was below 1, indicating to a partial dominance in heritability of this trait in both years. Results of the Vr/Wr regression analysis point out to a partial dominance in heritability of the number of rows per ear. Moreover, a presence of non-allelic interaction was detected, which indicates to a need to study effects of epistasis as it can be more important in certain hybrids. The greater value of additive variance resulted in greater narrow-sense heritability for the number of rows per ear in both years of investigation (86.83% and 69.44%, respectively).