الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
The aim of this investigation was to determine the extent of heterosis and
types of gene action and their interaction with two environments (The first normal
treatment five irrigations and 70 kg N/ fed, and the second, one irrigation + 30 kg
N/fad) for some growth and yield characteristics, i.e. heading date, physiological
mature date, plant height, peduncle length, spikelets per spike, spike length,
number of grains per spike, 1000- kernel weight, grain yield per plant, straw yield
per plant, number of spikes per plant and harvest index. The susceptibility index
(SI) was calculated for each season (the first and second experiments in each
season) from origin data for yield and its components before using a generalized
formula [Fischer and Maurer 1978].Also, the three drought measurements
leaf temperature (LT), stomatal resistance (SR) and transpiration rate (TR) were
estimated in the second season.
Seven parental varieties of wheat representing wide range of variability in
most of the studied traits were utilized These varieties were Gemmiza 3(Pl),
Sakha 61 (P2), Giza 162 (P3), Sakha 8 (P4), Sids 9 (P5), Sids 6 (P6) and Sids 4
(P7). Crossing among the parental materials by means of diallel system was
initiated at 1995/96 season” In 1996/97 season, half diallel set of crosses involving
seven parents and 21 F1 hybrids were evaluated under two environments (two
experiments). Each experiments was sown on 7-12-1996 in a randomized
complete block design with three replications. The two experiments were planted
in two adjacent fields. The first experiment was fertilized and irrigated with the
recommended treatment i.e. five irrigations and 70 kg NI fad. applied in three
equal doses, at planting, first and second irrigations. The second one fertilized 30
kg N 1 fad in two equal dose first with sowing and the second with the first
irrigationat. In 1997/98 season, the same two experiments in the previous season
was repeated. In both seasons each experiment was designed in randomized
complete block design with three replications in the experimental farm at Sakha
Agric. Res. Sta, Kafer EI-Sheikh Governorate . In both seasons of evaluation,
each plot consisted of one row, each row was 4 m long and 30 cm apart. Plants
within row were 20 em apart. The dry method of planting was used in this
concern. Data were recorded on seven to ten chosen at random from each plot. -
The data were genetically analysis by the procedures by Griffing (1956) and
Hayman (1954).
The results obtained can be summarized as follows:
I-Growth,yield and its components:
A:Analysis of variance, means and heterosis :-
1- Environment mean squares were significant for all traits except number of
spikelets per spike in the second season and number of spikes per plant in the
first season .
2- Significant genotypes mean squares were obtained for all traits except number
of spikelets per spike in both environments as well as the combined analysis in
the second season and under stress environment in the first season and peduncle
length at the stress environment in the second season.
3-Significant genotypes x environments mean squares were obtained for all
studied traits in both seasons except plant height and number of spikelets per
spike in both seasons, peduncle length, spike length and number of kernels per
spike in the second season.
4-Mean squares due to parents were significant for all traits except for number of
spikelets per spike in both environments as well as the combined analysis over
them, in the second season number of spikelets per spike and peduncle length
in stress environment in the first season . Significant mean squares due to
interaction between parental varieties and environments in both seasons were
detected for all the studied traits except peduncle length, plant height, number
of spikelets per spike and straw yield in both seasons, spike length, number of
spikes / plant number ofkemels / spike, grain yield / plant and maturity date in
the second season and heading date in the first season.
5-The varieties Sids 9, 6, 4 behaved as the earliest ones. The parental varieties
Sakha8, Giza 162 gave the highest values for grain yield per plant
6-Significant crosses mean squares were detected for all the studied traits except
number of spikelets per spike under both environments in the second season and
peduncle length and number of spike lets / spike in stress environ ment in the
first season .Significant mean squares due to interaction between crosses and
environments were detected for all the studied traits except peduncellength,
spike length and number of spikes per plant in the second seeason ,straw yield
in the frrst season and plant height and numer of spikelets / spike in both
seasons. The four crosses (l x 2), (2 x 6), (2 x 4) and (2 x 7) had the heighest
grain yield per plant .
7-Mean squares for parent vs crosses were significant in both environments as
well as the combined analysis for all investigated traits except spike length in
both environments as well as the combined analysis in both seasons; number of
spikelets per spike and number of spikes per plant in both environments and the
combined analysis in the second and first seasons irrespectively. For maturity
date, the crosses (2 x 3) and (3 x 7) expressed significant negative heterotic
effects relative to better parent. Also, the crosses (1 x 2), (1 x 6) and (2 x 7) had
the highest heterotic effects relative to better parent for grain yield per plant.
B-Combining ability
8-The mean squares associated with general combining ability were significant for
all traits. Specific combining ability (SeA) mean squares were significant for
all studied traits except maturity date and number of spikelets per spike in the
combined analysis in the first season, maturity date under stress environment
and the combined data in the second season, peduncle length under stress
environment in both seasons, and spike length at normal and stress
environments in the second season. It is evident that additive and additive by
additive types of gene action were the more important part of the total genetic
variability for maturity date and number of spikelets / spike in the combined
analysis in the first season maturity date in stress environment and the
combined data in the second season, peduncle length under stress environment
in both seasons and spike length in both environments in the second season. For
the other studied cases • both additive and non- additive gene effeits were
involued in determining the performance of single cross progeny.
9- The mean squares of interaction between environments in separate season and
both types of combining ability were significant for maturity date and harvest
index in both seasons, peduncle length, spike length, number of spikes / plant •
IOOO-kernel weight, grain yield / plant and straw yield / plant in the first season
, and heading date in the second.
lO-The parental varieties Sids 9, 6 and 4 for spike length and number of kernels
per spike; parental variety Gemmiza 3 for 1000- kernel weight and Sakha61 for
number of spikes / plant, grain yield per plant and harvest index, gave the
highest desirable (Qi) effects for traits.
II-The parental combinations (3 x 4) and (3 x 7) for maturity date, ( I x 5) and
(2x7) for number of spikes per plant and (2 x 6) and (2 x 7) for grain yield per
plant had the desirable (Sij) effects for these traits.
C-Genetic components
12- Significant (D) valves were detected for all traits under both environments in
both seasons except pudencle length under normal environment in the first
season and harvest index in stress environment in the second season. Significal
values for the dominance component (Hl) were obtained for all the studied
traits in both environments in both seasons, except spike llength in both
environments and peduncle length in stress environment in the second season.
Values of (Hl) were large in magnitude, than the respective (D) ones for most
eases.
l3-Studies on degree of dominance revealed the existence of overdominance for
all traits except heading date spike length, number of spike / plant and number
of kernels / spike at both environments in the first season spike length and
number ofkemels / spike at both environments in the second season, maturity
date under normal environment in the first season and maturity date and
peduncle length under normal and stress environment, res pectiwly in the
second season.
14.High to moderate heritability values in narrow sense were detected for all traits
except maturity date and peduncle length at stress environment in the second
season, and peduncel length at normal environment in both seasons 1000-
kernel weight at normal environment in the second. season and at stress
environment in both seasons and harvest index in both environments in both
seasons.
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2-Sosceptibility index
A-Analysis of variance, means and heterosis
IS-Environments mean squares were insignificant for SI for all the studied trait
except maturity date, harvest index, number of spikelets per spike and spike
length.
16-Significant genotypes mean squares were significant for most cases .Also,
significant mean squares of interaction between genotypes and seasons were
obtained for heading date, peduncellength, spike length, number of spikes per
plant, 1000- kernel weight, grain yield, straw yield and harvest index.
17-The parent Giza 162 gave the desirable SI for earliness, harvest index and
peduncel length . However the parental Sakha8 showed the desirable Sf for
grain yield and maturity date.
18-Mean squares for parents vs. Crosses as an indication to average heterosis
overall crosses were significant for SI in maturity date, number of spikes per
plant, grain yield in separate season as well as the combined data, 1000-
Kernel weight, straw yield and peduncle length in the first season and heading
date and SR and TR in the second season. The best crosses for SI of grain
yield per plant were (1 x 3), (1 x 7), (2 x 4), (2 x 5) and (4 x 7) in the first,
and second seasons.
B- Combining ability
19-The mean squares associated with general and specific combining ability
(GCA and SCA) were highly significant for most casses. High GCA / SCA
ratio which largely exceed the unity was obtained ofSI for most studied traits.
Low GCA / SCA ratio less than unity was detected for number of spikes per
plant and harvest index in the combined analysis, and number ofkemels per
spike and heading date in the first season.
20-The mean squares of interaction between seasons and both types of combining
ability were significant for SI for heading date, peduncle length, number of
spikes per plant, 1000- kernel weight, grain yield per plant, straw yield and
harvest index, indicating that the magnitude of all types of gene action varied
from season to another.
21-The parental variety Sakha 61 seemed to be the best combiner for SI in number
of spikes per plant, straw yield / plant and grain yield / plant in both seasons as
well as the combined analysis, and heading date, harvest index and
transpiration rate in the second season and it, gave insignificantly (91) effects
for SI of most other traits .
22-The desirable SeA values were recorded by fire crosses (1 x 7 ), (2 x 6) and (5
x 6) for SI in number of spikes per plant and three crosses (I x 7), (2 x 6), (2 x
7), and (2 x 5) of SI for grain yield per plant in the combined analysis.
C-Genetic com.,ponents
23-Significant values for the dominance and additive component (HI) and (0) of
SI were obtained for all traits except (0) component for heading date in both
seasons, peduncle length, straw yield, harvest index and LT in the second
season.
24-Studies on degree of dominance revealed the existence of overdominance for
most traits.
25-Low heritability values in narrow sense were detected of SI for all traits,
indicating that most of genetic variance may be due to non- additive genetic
effects
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3-Drought measurements:
A-Analysis of variance, means and heterosis
26-Environment mean squares were highly significant for the three drought
measurements, indicating an overall differences between the stress and normal
conditions. LT and SR, mean values of stress condition were generally higher
than of normal. Meanwhile for TR in normal condition were generally higher
than those of stress condition.
27-Significant genotypes, parent, and FI hybrids mean squares were detected for
all the studied measurements in separate environment as well as the combined
analysis. Also genotypes x environments and crosses x environments
interactions were significant for the three measurements
28-Mean squares for parents vs. crosses as an indication to average heterosis over
all crosses were significant for all measurements in both environments as well
as the combined analysis.
B- Combining ability:
29-General and specific combining ability mean squares were significant for the
three drought measurements except GCA mean squares under stress and the
combined analysis for LT. Low GCA / SCA ratio of less than unity were
obtained for all the studied traits, except TR at normal enviromnent indicating
that the predominance of non- additive gene action in the inheritance of such
cases.
30-The mean squares of interaction between environments and both types of
combining ability were significant for the three drought measurc:~ments.
31-The parental cv. Gemmiza 3 expressed significant desirable (g.) effects for TR
in stress environment, the parental cv. Giza 162 gave insignificant (gr) effect
for the three drought measurements. The parental cv. Sakha 61 had significant
desirable (g.) effect for LT in the normal environment, where the parental cv.
Sakha 8 had significant positive (gi) effect for SR in stress environment.
32-The parental combinations (6 x 7), (3 x 5) and (1 x 7) for LT, ( 1 xl), (1 x 5),
(2 x 6), ( 2 x 7), ( 3 x 4) and (4 x 6) for SR, (l x 2), (l x 5), ( 2 x 6) , (3 x 4)
and (4 x 7) for TR, appeared to be the most promising for breeding for these
measurements.
C-Genetic components
33-Significant values for the dominance and additive components (HI) and (D)
were obtained for all traits except (D) component for LT at stress environment
and SR at normal environment Significant (h2
) values were detected for all
traits except LT at strees environment and TR at normal environment.
34- Low heritability values in narrow sense were detected for all measurements