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.

Cilj istraživanja je da se za tri komponente prinosa paradajza procene: heterozis u odnosu na boljeg roditelja, komponente genetičke varijabilnosti, heritabilnosti osobina na bazi dialelnog ukrštanja i izvrši VrWr regresiona analiza. Odabrano je šest različitih linija paradajza poreklom iz domaćeg i introdukovanog selekcionog materijala. Hibridi su u odnosu na linije ispoljili veće srednje vrednosti za većinu osobina. Vrednost aditivne komponente varijanse (D) veća je od dominantne (H1 i H2) za broj plodova po biljci i prosečnu masu ploda, dok je za masu ploda po biljci dobijena veća vrednost dominantne komponete varijanse. Pozitivne vrednosti interakcije aditivni x dominantni efekat gena (F) za ispitivane osobine ukazuju da je u nasleđivanju ovih osobina veće učešće dominantnih alela, a to potvrđuju i koeficijenti H2/4H1 (0,208-0,228) kao i odnos Kd/Kr koji su veći od jedan (1,129-1,536). Vrednosti prosečnog stepena dominacije H / D 1 manje od jedan (broj plodova po biljci i prosečna masa ploda) ukazuju da se ove osobine nasleđuju parcijalnom dominacijom. Za masu ploda po biljci vrednosti stepena dominacije veći je od jedan, što ukazuje da se ova osobina nasleđuje dominacijom ili superdominacijom. Ove zaključke potvrđuju i visoke vrednosti heritabilnosti u širem i užem smislu koje su varirale od 98,88% - 99,44%, odnosno 45,06-87,51%, kao i VrWr regresije za ispitivane osobine u F1 generaciji.