ABSTRACT
Considerable attention is paid in the Egyptian National Wheat
Research Program to develop early maturing and high yielding cultivars.
Therefore, six early to moderate maturing bread wheat lines were crossed to
produce three cross populations. The six populations model was used
through three growing seasons from 2017/18 to 2019/20. The objective was
to determine the intra- and inter-allelic gene interactions controlling
earliness and some agronomic traits as well as identify the best germplasm
which had accumulated early maturing gene pool. Results showed that late
sowing date in end of December decreased all studied traits. Both additive
and dominance gene effects and variances were important in inheritance of
the studied traits. Additive effects and variance were larger than
corresponding dominance ones in most cases. Heritability in broad and
narrow sense and expected genetic advance as percent of F2 mean were
moderate to high for all the studied traits. Negative and significant
phenotypic and genotypic correlation between grain yield and earliness traits
were obtained. Generally, most biometrical parameters resulted from cross 2
(line 3 x line 4) and cross 3 (line 5 x line 6) were higher in magnitude
compared to cross 1 (line 1 x line 2), thus, these two crosses would be used
in breeding program for improving earliness and grain yield traits.