A half diallel set of crosses among six inbred lines of maize were evaluated at the
Maize Research Department (G.C.S.A.R.) in Damascus Governorate during 2010 and 2011
growing seasons to estimate heterosis and combining ability components for the n
umber of
rows per ear, number of kernels per ear, ear length (cm), ear diameter(cm), 100-kernel
weight (g), and grain yield (ton /hec).
The inbred lines, crosses, general combining ability (GCA) and specific combining
ability (SCA) mean squares were highly significant for all the studied traits, showing the
existence of a genetic variance among lines.
The ratios of GCA to SCA detected for the studied traits showed the dominance of an
additive gene action for all the studied traits except for 100-kernel weight and grain yield
which showed the predominance of a non-additive gene action.
The heterosis percentage for the studied traits was significant based on mid and
better parents.
The GCA effects showed that the lines CML.317, CML.371, CML.373 and
CML.367 were good general combiners for grain yield, while the SCA effects showed that
seven hybrids were the best F1 cross combinations such as (CML.317×CML.371) for grain
yield.
