الفهرس 
REVIEW Of LITERATUREOnly 14 pages are availabe for public view
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Abstract
A diallel cross set was carried out among six parents of common wheat
without reciprocal crosses to study the inheritance of heading date, maturity date,
plant height, spike length, number of spikes per plant, number of kernels per
spike,1000 grain weight and grain yield per plant using Griffing (1956) , Hayman
(1954) , Jones (1956) and the graphical analysis Johnson and Aksel (1959). The
parental varieties and their possible 15 crosses were sown under two different
nitrogen levels i.e.,70 kg/faddan (normal)and 35 kg/faddan (stress) using
randomized complete block design with three replicates per each nitrogen level.
A. Griffing method:
Mean squares for fertilizations were found to be significant for all traits
studied except days to maturity and plant height, indicating differences between
the two different nitrogen fertilization levels for most characters.
Genotypes, parents and the resultant crosses mean squares were found to be
highly significant for most traits studied at the two different nitrogen levels and
their combined data.
The interaction of genotypes with the two different nitrogen levels was
found to be highly significant for all traits studied except days to heading and
maturity date, plant height and 1000 grain weight, reflecting the fact that these
entries behaved differently from nitrogen level to another.
The interactions of the two different nitrogen levels with parents were found
to be significant for all traits studied except days to heading, plant height and 1000
grain weight.
SUMMARY
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The interactions of the resultant crosses with the two different nitrogen
levels were found to be highly significant for no. of spikes per plant, no. of grains
per spike and grain yield per plant.
General combining ability (GCA) and specific combining ability (SCA)
mean squares were found to be highly significant for most characters under
examination under the nitrogen fertilizer levels and their combined data.
The GCA/ SCA variance ratios revealed the greater importance of additive
and additive x additive types of gene action in the inheritance of days to heading,
days to maturity, number of grains per spike and spike length at both nitrogen
fertilizer levels and their combined data.
The interaction of the two different nitrogen fertilizer levels with general and
specific combining ability mean squares were found to be highly significant for
number of spikes per plant, number of grains per spike, spike length and grain
yield per plant.
The parental varieties Sids 12 and Gemmeiza 11 showed highly significant
negative general combining ability effects for days to heading at the two nitrogen
fertilizer levels and their combined data, also Gemmeiza 11 proved to be good
combiners for days to maturity at the two nitrogen fertilizer levels and their
combined data. The parental variety line 4 proved to be a good combiner for spikes
per plant. The wheat varieties Sids 12, line 3 and line 4 proved to general good
combiners for number of grains per spike. The three parental varieties Sids12,
Gemmeiza11 and line4 (P6) proved to be excellent combiners for spike length. As
for 1000-grain weight, varieties Sids12, Gemmeiza11 and line4 proved to be
excellent combiners. The three wheat varieties Sids12, Gemmeiza11 and P6 (line4)
proved to be excellent general combiners for grain yield per plant.