الفهرس 
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Abstract
The present investigation was carried out at El-Mattana Agric. Res.
Station, Agric. Res. Center, Egypt, during the three successive seasons of
2000/2001, 2001/2002 and 2002/2003.
The objective of the present investigation were to estimate mean
performance, heterosis, general and specific combining abilities, as well as,
correlations between different traits. The materials used in the this study
were 7 durum wheat varieties (Triticum turgidum var. durum) differed
widely in their genetic background and origin, i.e. Kucuk, Rascn/Kitti,
Yavaros-79 (Bani Sweif 1), Terbol 97-4, Waha, Sohag 2 and Sohag 3.
Parental genotypes, F1 hybrids and F2 populations were grown in
a complete randomized block design with three replicates. The results
obtained from this study are summarized in the following:
1- Mean performance:
[1] Days to heading: Significant differences were observed among all
studied genotypes the F1 crosses were later or intermediate in spike
emergence between the respective parents, except three crosses
which possessed the same values of its parents. On the other F2
crosses were earlier or intermediate in spike emergence between the
respective parents except two crosses which were later than the
respective parents and three crosses possessed the same values of its
parents.
[2] Days to maturity: most of F1 crosses were later than its respective
parents, while most of F2 populations were intermediate or later in
values of days to maturity between the respective parents.
[3] Flag leaf area: wide variation was observed among all genotypes
under study for flag leaf area. Some of F1 crosses were higher than
their respective parents, whereas eleven of crosses of F2 populations
were intermediate while the other genotypes were lower and/or
higher than their respective parents.
[4] Plant height: all F1 crosses were either taller or intermediate in
height comparing with their respective parents. The same trend with
some modifications was found in F2 populations, except two crosses
(Kucuk x Waha) and (Waha x Sohag-3) which were shorter in height
compared to the respective parents.
[5] Number of spikes/plant: All F1 crosses were either higher and/or
intermediate in number of spikes/plant comparing with their
respective parents. Except three crosses which produce fewer tillers
than its respective parents and one crosse gave the same values of
one of its parents. whereas eleven of F2 populations were higher,
seven population were intermediate and three crosses only were
fewer in tillers than their respective parents.
[6] Number of kernels/spike: Wide variation was observed among all
studied genotypes. All F1 crosses were either intermediate and/or
higher in values of kernels per spike comparing with their respective
parents except five crosses showed lower number of kernels per
spike compare to the respective parents, whereas all F2 crosses were
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lower or intermediate in number of kernels per spike, except one
cross only (Yavaros-79 x Waha) was higher than its respective
parents.
[7] Biological yield per plant: significant differences were observed
among all parental lines, as well as, among F1 crosses and F2
populations. For F1 crosses 8 were higher, 10 were intermediate and
3 crosses were lower in values of biological yield/plant. With
respect to F2 populations 8 crosses were higher, 7 were intermediate
and 7 crosses were lower than their respective parents.
[8] Grain yield/plant: significant difference were observed among all
parental lines, as well as, among F1 crosses and F2 populations. For
F1 crosses: 9 were higher, 8 intermediate and 4 crosses were lower
in values of grain yield/plant. With respect to F2 populations: 8
crosses were higher, 8 were intermediate and 5 crosses were lower
than their respective parents.
[9] Harvest index: nine crosses of F1 crosses and ten of F2 populations
exceeded their respective parents in values of harvest index,
whereas the other genotypes were intermediate or lower than their
respective parents.
[10] 100-kernel weight: mean performance of the parental lines, F1
crosses and F2 populations were differed significantly in 100-
kernel weight most of F1 crosses, as well as, F2 populations
showed higher values of 100-kernel weight than respective
parents.