الفهرس 
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Abstract
The main objective of this investigation was to determine
the extent of heterosis and combining ability estimates and their
interactions with environments for some agronomic characters
and susceptibility index (SI) for yield and its components in
some faba bean genotypes and their hybrids. Seven parental
genotypes namely, Giza blanka (Pj), Giza-717 (P2) Triple-white
(P3), Giza-643 (P4), Giza-461 (Pj), Moshtohor-109 (P6) and
Moshtohor-l03 (P7) representing wide range of variability in
most of the studied traits were utilized.
In 1999/2000 season, two experiments were conducted,
each experiment include the seven parents and their 21 Fl
hybrids, which were sown on zo” ovember 1999. in a
randomized complete block design with three replications. The
two experiments were planted in two adjacent fields. The first
experiment was normally irrigation and the second one was
irrigated at sowing, then plants were left to grow under rainfed
(stress environment).
Data were recorded on 10 guarded plants, randomly
sampled from each plot for F1 generation where the studied traits
were plant height, first fruiting node, yield and some of its
components.
The susceptibility index (SI) was calculated for the two
environments (normal and rainfall irrigation) from origin data for
yield and yield components before, using a generalized formula
(Fischer and Maurer 1978).
An ordinary analysis of variance was firstly performed
for each experiment and then a combined analysis was carried
out whenever homoge eity of error variances was realized.
Heterosis was computed as mean squares and as the percentage
deviation of FImean performance from either the mid-parent or
the better parent average values for each individual cross.
General and specific combining ability estimates were obtained
by employing Griffing s diaIlel cross analysis (1956) designated
as model-1 method -2.
The obtained results can be summarized as follows:
1- Growth, yield and yield components:
A-Analysis of variance, means and heterosis:
I) Environments mean squares were significant for all the
studied traits. The mean values of all traits in the normal
irrigation were significantly higher than those in rainfall
condition.
2) Significant genotype mean squares were obtained for all traits
in both environments as well as the combined data.
Significant genotype environment mean square was
obtained for all the studied traits.
3) Mean squares due to parents were significant for all the
studied traits except plant height under normal irrigation and
number of branches/plant under rainfall and the combined
data. Significant mean squares due to interaction between
parents and environments and were detected for all the
studied traits except plant height number of branches/plant
number of seeds/plant and 100-seed weight
4) The variety Giza blanka (Pj) gave the highest values for seed
yield and number of seeds/plant number of branches/plant
and seed index in both environments as well as the combined
analysis.
5) The variety Giza-717 (P2) gave the highest values for plant
height in both environments as well as the combined analysis.
6) Crosses mean squares were significant for all the studied
traits revealing an overall differences between these hybrids.
Significant mean squares due to interaction between crosses
and environments were detected for all traits.
7) The cross; Triple white (P3) Giza 461 (Pc) showed
significant higher mean values for number of pods/plant in
both environments as well as the combined data followed by
cross Giza blanka (Pj) x Moshtohor 109 (P6) under normal
irrigation and cross Giza-717 (P1) x Triple white (P3) under
rainfall and the combined data.
8) The two crosses’ Giza blanka (Pj) x Giza-7l7 (Pz) and Giza
blanka (Pt) x Moshtohor 109 (P6) under normal irrigation, the
two CTossesGiza blanka (Pt) x Giza-461 (Pj) and Giza blanka
(P 1) Giza- 717 (Pz) under rainfall and the combined data
gave the highest number of seeds/plant.
9) The two crosses; Giza-717 (Pz) x Giza-461 and Triple white
(P3) x Moshtohor 103 (P7) under normal irrigation, Giza-717
(Pz) x Moshtohor 103 (P7) under rainfall and two crosses
Giza-717 (P2) x Moshtohor 103 (P7) and G12a-717 (P2) x
Giza-461 (Ps) in the combined analysis gave significant
higher lOO-seed weight than other crosses.
10) The four crosses; Giza blanka (P,) x Giza-717 (P2), Giza
blanka (PI) x Triple white (P3), Giza blanka (PI) x Giza-46I
(Pe) and Giza-717 (P2) x Moshtohor-103 (P7) gave the highest
mean values for seed yield/plant under normal inigation. The
four crosses; Giza blanka (PI) x Giza-461 (Ps), Giza-717 (P2)
x Triple white (PJ), Giza-717 (P2) x Moshtohor-109 (P6) and
Triple white (P3) Moshtohor-l09 (P6) gave the highest
values under rainfall irrigation and four crosses; Giza blanka
(Pj) x Giza-717 (P2) Giza blanka (PI) x Triple white (P3),
Giza blanka (PI) x Giza-46 I CPs) and Giza-717 (P2) x
Moshtohor 103 (P7) gave the highest seed yield/plant under
the combined data of both environments.
I I) Mean squares for parents vs. crosses as an indication to
a erage heterosis overall crosses was of appreciable
magnitude in both environments (normal irrigation and
rainfall) as well as in their combined analysis for all traits
except plant height and number of branches/plant in rainfall
condition. Significant parents vs. crosses x environment
interaction was detected for plant height, first fruiting node
and number of pods/plant.
12) For seed yield/plant seven, nine and twelve crosses
significantly surpassed the mid-parent alue in the normal
rainfall irrigation and the combined data respectively. Of all
hybrids, four, three and two ones hybrids exhibited
significant positive heterotic effects relative to better parent
in the same order. In the combined data the two crosses’
Giza-717 (P2) x Mo htohor-103 (P7) and Triple white (P3) x
U1\.1MARY _
ltohor-103 (P7) showed desirable heterotic effects
ve to better parent with greatest advantage being 25.8%.
bining ability:
mean squares associated with general combining ability
.A.) and specific combining ability (S.C.A.) were
significant for all the studied traits. The mean squares of
interaction between inigation treatments (Env.) and both
types of combining ability were significant for all traits.
2) High G.C.A./S.C.A. ratio exceeded the unity for all the
studied traits except number of pods/plant in both
environments as well as the combined data and 1DO-seed
weight under normal irrigation, indicating the predominance
of additive type of gene action in the inheritance of such
traits.
3) The ratios for S.C.A. x Environment/S.C.A. was higher than
ratios of G.C.A. x Environment/G.C.A. for all traits except
plant height, first fruiting node and number of pods/plant.
4) The parental varieties Giza blanka (Pi) and Giza- 717 (P2)
gave significant positive gi for yield and one or more of its
components in normal irrigation and rainfall as well as the
combined data.
5) The combination Giza blanka (PI) x Giza-461 (Ps) and Giza
717 (P2) x Moshtohor-103 (P7) appeared to be the best
promising for breeding to increase seed yield per plant which
gave significant positive Sij for yield and some of its
component in both environments as well as the combined
data.
2: Susceptibility index (SI)
A- Analysis of variance, means and heterosis:
1) Mean squares of genotypes, parents, crosses and parents vs.
crosses were highly significant for SI of yield and its
components except parents vs. crosses for SI of number of
pods/plant and IDO-seedweight.
2) Of all hybrids eleven, thirteen, thirteen and fourteen ones had
the highest tolerance of stress environments for number of
pods and seeds/plant, seed yield/plant and 100-seed weight,
respectively. While the crosses; Giza- 717 CP2) x Moshtohor-
103 (P1) and Giza-717 (P2) Triple hite (P3) for number of
pods/plant, Giza blanka Il’j ) x Giza-461 CPs) Giza-717 (P2) x
Triple white (P3) and Giza-643 CP4) x Giza-461 (P-) for
number of seeds/plant, Giza-717 (P2) x Moshtohor-l03 (P1)
Giza-717 (P2) x Moshtohor 109 (P6) Giza blanka (PI) x
Moshtohor 109 (P6), Giza-717 (P2) x Giza-643 CP4) and Giza-
461 CPs) x Moshtohor 109 (P6) for IDO-seedweight and the
crosses Giza blanka CPt) x Giza-461 CPs), Giza-717 (P2) x
Moshtohor-l09 CP6) and Giza-643 (P4) x Giza-461 (P-) for
seed yield/plant seemed to be the best tolerant crosses for
these traits.
3) Ten and six parental combinations significantly exceeded
mid-parent and better parent, respecti ely for SI of seed
yield/plant. The crosses’ Giza-643 CP4) Moshtohor-l09 (P6),
Giza blanka (PI) x Giza-461 CPs), Giza-643 (P4) x Giza-461
(Ps), Giza blanka (PI) x Giza-643 CP4) and Triple white (P3)x
Moshtohor-109 (P6) had the best desirable heterotic effects
for thi strait.
B- Combining ability:
1) The mean squares associated with general and specific
combining abilities were significant for 81 of yield and the
three yield components. Also, low G.C .IS. CA. ratios of
less unity were detected for number of seeds/plant seed
yield/plant and 1aO-seed weight.
2) The parental cv. Giza-717 (P2) seemed to be the first
combiner for SI of number of pods/plant and the second one
for 51 of number of seeds and seed yield/plant and it ranked
the third combiner for IOo-seed weight.
3) The parental cv. Giza-461 (Pj) seemed to be the best
combiner for 81 of number of seeds and seed yield/plant. At
the same direction, it gave significant negative value for S1 of
100-seed weight. The parental cv. Triple white (P3) e pressed
negative significance SI for number of pods/plant and 100-
seed weight. While, the parental cv. Giza-643 (P4) was highly
tolerant for 1DO-seedweight. Therefore, the two parental c s.
Giza-717 (P2) and Giza-461 (P5) could be considered as an
excellent parent in breeding programs towards releasing
tolerant variety for drought stress.
4) Six, nine, eight and eleven hybrids exhibited significant
negative Sij for number of pods and number of seeds/plant
1Ou-seed weight and seed yield/plant respectively which
indicates their tolerance for drought stress.