الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
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SUMi.-1ARY
The present investigation was carried out to study
the mutagenic effects of is -ray: and EMS, as single
treatments, on M1 germination, plant height, number of
tillers per plant, number of sterile spikelets per s~ke,
spike length, and number of spikelets per spike on two
durum wheat varieties i.e. Gerardo vz, stork1s’ .and two
barley varieties G •.121 and Bonus. Plant height, nuiDber
of tillers per plant, number of spikelets per spike,
spike length, number of kernels per spike and chlorophyll
mutations were studied, in iot” generation in one durum ”,
wheat variety Gerarda vz and one barley variety Giza 121
Seeds of each variet? were -irradiated with different
doses i.e. 10, 20, 30, 40, 50 and 60 fr or treated with
solutions of different concentrations (0.2%, 0.4%, 0.6%,’
0.8% and 1.0%) of EMS.
The results obtained are summarized as follows:
1- Effects on M1 germination:
A- Durum wheat:
The p entage of M1- seed germination was found
to be decreased about linearly with increasing the d-ray
dosage or EMS concentrations. Almost complete seed lethality
was obtained with the ~-ray dose 50 kr and with the
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EMS concentration, 0.3% in both durum wheat varieties.
B- Barley
complete seed lethality was not obtained with any
)-ray dose in the two barley· varieties where complete
seed lethali~ was found with EMS concentration O.~%.
II- Effect on M1 generation:
A- Durum wheat
Reduction in plant height, spike length, number of
spike lets per spike and fertility were found with two
mutagens in both two varieties increasing in number of
tillers per plant was obtained with ~ -ray. in Gerardo vz
and stork’s’.
B- Barley
Reduction in plant height, number of tillers per plant
fertility, Spike length and number of spikelets per spike
were obtained in the two barley varieties with gamma-ray
doses and EMS concentrations. These reduction were about
linearly with increasing the gamma-ray! d~sages or EMS concentrations.
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III- Effects on M2 generation
1- Plant height
A- Durum wheat
High significant decrease was obtained in plant
height at all radiation doses. Greated heritability value
is estimated at lower dose, while the lowest- heritabili~y
value was observed at the dose 40 Kr. EMS treatment caused
decreased in plant height. Greater heritability value was
found at 0.4 EMS concentration, while the lowest value was
found at 0.6%.
B- Barley
The plant height was decreased proportionally as
~-ray doses increased. Highest value of genetic variances ·.a.obtained at )).-ray dose of 30 KJJ. And it were aiuddenly
decreased at the~-ray doses higher than 30 Kr. Lower
coefficient of genetic variance and heritability values
wereQStimated at gamma-rays dose of 60 Kr.
The mean of plant height was decreased as EMe concenttration
increased. The values of both phenotypic and
genotypic variances were higher after all EMS treatments
and were greater than that after )(-ray •
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2- Effects on number of tillers per plant:
A- Durum wheat
The greatest heritability value was estimated with
the highest ~-ray’ of 40 kr, and it is moderate at EMS
concentration of 0.2% and 0.4%, lower value was found at
0.6% concentration.
B- Barley
The mean value of tillers per plant, phenotypic and
genotypic variances were proportionally increased as d-ray.
increased. EMS caused an increased in the mean number
of tillers per plants. phenotypic and genotypic variances
were increased as EMS concentration increased.
3- Effect on spike length:
A- Durum wheat
Either ~-ray or EMS resulted in reduction in the
length of the mean spike. EMS doses were more effective
than ’I-ray’, while the mean genetic variances after lI”-ray.·
averaged high than the average of genetic variation of the
EMS concentrations.
Boo: Ba-rley Rada1at1on and chemical mutagens resulted in reduction in
the spike length-GaMma-ray doses were more effective than
~-’~--~--~EMS·concentration.- Phenotypic and genotypic variances-·were----·~--- ..
increased as ’If -ray doses increased, lower her! tabili ty
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value was estimated was larger at EMC concentration as
it was compared with this ~-ray doses.
4- Effects on number of kernels per spike
The lower means were obtained under 40 Kr and 30 Kr
doses and the heritability estimates for the number of
kernels per spike increased as ~ -ray doses increased.
Highly significant differences between all treatments
and the control were obtained. The mean value decreased
gradually as the concentration of EMS was increased.
Highest genetic changes was found with 0.4% of EMC concentration.
B- Barley
Radiation treatments had little effect on the means
number of kernels, highest genetic va~iance and heritability
were obtained with 40 Kr. Chemical mutagens produced
high genetic variation than that produced by )(-ray .•
5- Effects of number of spikelets per spike:
A- Durum wheat
Decreasing of the number of spikelets per spike were
obtained after the higher doses of ~-ray • Lower doses
10 kr and 20 kr and 20 had greater effects OB genetic
changes than the highest doses. Phenotypic variances were
greater after chemical treatments than that after ~-ray
treatments.
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B- Barley
Lower doses had slight effect on the number of
spikelet per spike while the highest dose of ~ -ray:.
produced significant reduction. Genetic variance was
larger at 30 Kr dose. Lower genetic variance was estimated
at higher dose of ~-ray (60 Kr). High estimates for
phenotypic and genotypic variances were obtained after EMS
treatments.
6- Effect on mutation rate
A- Durum wheat
The two mutagens, ’l5-ray” doses and EMS concentration
induced chlorophyll mutation. The percentage of M
2
families segregation for chlorophyll on the average were
.
4.6% while after E}.·l”Streatments the percentage was 3.39.
B- Barley
The EMS is mostly efficient in inducing the chlorophyll
mutation than ’t -ray. The chlorophyll mutation
was increased as the ~-ray doses or EMS concentration
increased.