Inheritance of yield components in tomato

Abstract

The aim of the present study was to estimate, on the basis of diallel crossing, superior-parent heterosis, components of genetic variability and trait heritability for three yield components in tomato, and to perform the VrWr regression analysis. Six different tomato inbred lines originating from local and introduced breeding material were selected for the study. The hybrids expressed greater mean values for the majority of the traits than the inbred lines. The value of additive component of variance (D) was higher than the value of the dominant variance (H1 and H2) for the number of fruits per plant and the average fruit weight, while the value of the dominant component of variance was higher for the fruit weight per plant. Positive values of additive x dominant genetic effect interaction (F) for the observed traits point to a greater participation of dominant alleles in the inheritance of these traits, which was confirmed by the coefficients H2/4H1 (0.208-0.228) and by the ratio KD/KR being greater than unity (1.129-1.536). The values of the average degree of dominance H / D 1 , lower than unity for the number of fruits per plant and the average fruit weight, indicate that these traits were inherited by partial dominance. Furthermore, values of the degree of dominance greater than unity for the fruit weight indicate that this trait was inherited by dominance or superdominance. These conclusions were also confirmed by high values of the broad- and narrow-sense heritability that varied from 98.88% to 99.44%, i.e., from 45.06 to 87.51%, respectively, as well as, by the VrWr regression for the observed traits in the F1 generation.