The influence of genes on genetic and phenotypic variability of yield in maize exotic population

Abstract

The investigations included mean values, genetic variability and phenotypic variability, heritability and genetic and phenotypic coefficients variability of yield in basic maize with 25% of the exotic germplasm incorporated and also, in the population after three and five cycles of gene recombining. To investigate influence of different cycles of gene recombinations, the trial was established after Nested Design method in two replications, on two locations. On the basis of the results obtained, it was concluded that the mean values had increased more significantly to the third than from the third to the fifth cycle of free hybridization. The additional gene recombinations influenced on the nonsignificant decrease of the genetic and phenotypic variability of grain yield. Estimated values of heritability were high and significant for yield, which indicates that they are mostly determined by the additive variance. The additional cycles of gene recombinations caused the decrease of heritability and coefficient of genetic and phenotypic variability. Bigger grain yield after three and fife gene recombination cycles, relating to the basic population, indicates to the positive effect of the additional recombination cycles to the increase of gene frequency in case of desirable traits, and the frequency of the more yielding genotypes.

Proučavanjem je obuhvaćena populacija kukuruza koja u sebi ima 25% egzotične germ-plazme (1601/5 x ZPL913)F2R0 i populacija nastalih posle tri (1601/5xZPL913)F2R3 odnosno pet (1601/5 x ZPL913)F2R5 godina rekombinovanja. Ogled je postavljen po metodu Nested dizajna u dva ponavljanja na dve lokacije u toku dve godine (1993. i 1994). Prosečan prinos se povećao, a genetička i fenotipska varijansa za prinos se nisu značajno smanjile pod uticajem broja ciklusa rekombinacija i dovoljno su visoke da omoguće uspešno oplemenjivanje. Ovu populaciju treba u daljem procesu selekcije podvrgnuti delovanju metoda rekurentne selekcije.