This study was undertaken at Experimental and Research Center, Faculty of Agriculture, at Moshtohor to
estimate genetic variance components as well as the expected gain from different methods of selection in maize.
A design 1 mating system consisting of 36 males crossed to four females was developed in new synthetic
"Moshtohor2" in 17
th
May 2008 season. These entries were evaluated in 30
th
May 2009 season. The studied traits
were: tasseling and silking dates, ear length, ear diameter, no. of rows/ear, no. of kernels/row, 100-kernel weight
and grain yield/plant. Genetic components were calculated according to Comstock and Robison, (1948). The
estimates of genetic and environmental variances were used to calculate the expected genetic gain in intrapopulation according to Hallaur and Miranda, (1981). The male and female variance components were
significant for all traits. The additive genetic variance was significant for all traits except ear diameters.
However, the dominance genetic variances were significant for all traits except ear length and no. of
kernels/row. Ratio of
2
D/
2
A was over dominance for all traits except ear length and no. of kernels/row where
partial dominance was detected. In general, the dominant genetic variance was more important than additive
variance for all traits. Low to moderate heritability values in narrow sense were obtained for all traits. The
heritability values ranged from 0.68 for no. of kernels/row to 0.10 for ear diameter. The expected genetic
improvement gain% from selection for grain yield/plant was 7.54, 15.08, 3.61, 7.22, 9.02, 12.57, 24.1 and
18.94% ∆g%/cycle by mass selection one sex and two sexes, modified ear-to-row one sex and two sexes, halfsib selection, full sib selection, test cross and s1 selection, respectively. The most efficient scheme would be test
cross population followed by S1
selection.
Key words: Maize, Genetic Variance, Additive, Dominance, Heritability, Selection Methods. |
