This study was carried out during the period from 2004/05 to 2006/07 growing seasons, at
Faculty of Agriculture, Sohag University, Egypt to estimate observed and expected response
to selection and other genetic parameters and calculate drought
susceptibility index. Results revealed highly significant differences
between F3 and F4 families under normal and drought conditions
for days to heading, spike length, no. of spikes/plant, no. of
kernels/spike, 100-kernel weight and grain yield/plant.
Observed direct response to selection for days to heading was
negative and highly significant compared with bulk and the
check cultivar in F4 with values of -5.58 and - 13.88 % and -6.13
and -13.88 % under normal and drought conditions, respectively.
The expected response to selection was 3.15 and 3.68% under
normal and drought conditions,respectively. Observed direct
response to selection for grain yield/plant was positive and
highly significant compared with bulk, better parent and the check
in F4 with values of 28.19, 18.59 and 26.09 % and 27.49, 16.67
and 21.20 % under normal and water stress conditions, respectively.
On the other hand, the expected response to selection
was 11.98 and 9.06% under normal and drought conditions, respectively.
Phenotypic and genotypic coefficients of variation under
normal conditions for days to heading of the early families
were 4.75 and 4.26% in F3 and 5.17 and 4.84% in F4 generation,
respectively. While under drought stress conditions those
values were 4.26 and 4.05% in F3 and 4.84 and 4.78% in F4 generation,
respectively. Phenotypic coefficient of variation for grain
yield of the highest yielding families under favourable conditions
was 14.57 and 13.40 % in F3 and F4 generations, respectively,
while, it was 13.32 and 12.43 % in the same generations,
respectively under water stress conditions.