الفهرس 
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Abstract
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SUI.tLtARY
The :present investigation was carried out aiming to
study th~ halophytic features of barley plants (Sahrawy
cultivar) grovmunder different salinity levels. Some
biuchemiQal measurements representing by the analysis of
crude protein, total carbohydrates, amino acids and mineral
contents in shoots and grains were taken as indications
for the $daptabil~ty of such pla~t species. Besides, complementary
~nformations on growth and yield characters were
tested t$ evaluate the relevance of the biochenical measurments
to pla~t adaptation. On the other direction, the
corrective influence of some cytokinins and growth retardants
on growth, yield and metabolism were also tested under
different levels of salinity.
Two pot-experiments were conducted during 1978/79 and
1979/80 seasons under green-house conditions. Seeds were
sovm in November, 15 for both seasons in glazed porcelain
pots filled with 25 Kg sandy soil of EI-Tahrir Province.
Thinning was performed 44 days from sovdng leaving 20 plants
per pot.
The cytokinins used were kinetin and benzimidazole
whereas the growth retardants were Alar and Phosphone.
Such growth regulators were applied twice as foliar spray
20 and 44 days fram sovnng in the levels: 20, 10, 500,
500 ppm, respeotively.
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Four HaCl salinity treatments, in addition to control
(tap water), were used namely: 6000, 8000, 10000,and
12000 ppm. Salinity treatments were applied 34 days after
so,nng. The treatment conditions were arranged in randomized
block desingn with 5 replications.
Combined fertilizer (NPK) was applied together with the
first irrigation of saline water 34 days from sovdng.
For both seasons, three samples of shoots were taken
stem elongation, boating and heading stages (44, 62 and 80
days from sowing, respectively). At such growth stages,
plant fresh weight, plant dry weight, plant height and leaf
area as well as the content of total carbohydrates, ctude
protein, free amino acids and mineral content were measured.
Grain yield per plant and number of tillers as well as some
.other characters representing by grain weight per spike,
number of grains per spike, lOOO-grain weight, were measured
at harvesting time (110 days from sowing). Similarly, the
biochemical measurments that carried out in shoots were also
determined in grains except of free amino acids that detected
only in shoots. Instead, protein amino acids were
measured in grains.
The obtained results can be summarized as follows:
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:. Salinity Effect2
1. Values of fr cch ·;!eight./plant, Leaf area arid pLan t
heigh t vtex:« not grea t Ly aff cc t ed af t CY’ she !,t ) cri.o d 0:
salini ty exposure. Howev er-, .;i th pr oLong oo exposure
period, the retarding effect of salinity was noticed even
under the low’ salinity levels.
2. Dry wei&~t/pl&~t was not greatly affected during
the stem c.l onga t.Lon ard boating stages at most levels of
salinity. A significant increase, ho~ever, was noticed at
the boating stage in plants treated with 6000 ppm level and
sometimes with 8000 ppm level. The depressive effect of
high salini ty 1 evels app eared only at ’~heheading stage.
The lowest level of salini ty (6000 pnn ) ViaS 2till st1.~:.:le..-
tive for dry ~eight accumulation.
J. Number of tillers was not signific~~tly affected
with the application of low salinity level (6000 ppm), whe~eas
a signifi cant decrease resul ted ’xith further ri ee Ll
salini ty 1 evel .
4. The increase of salinity level has resulted in a
significant decrease in grain yield, it ~as enhanced only
at the 1st season under low s~linity level (6000 ppm) but
being slighly lower than the control at the 2nd season.
5. Numb ar- and Y{eight of grains per spike showed gradual
increase vrith increasing salinity levels up to 8000 ppm.
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Values of grain ~eight/spike were more or less similar to
the control in the highest salt treatment (12000 ppm),
whereas thODe of grain number being still higher.
6. The average weight of lOaO-grains decreased gradually
with increasing the level of salinity, in some cases,
the lowest salinity level appeared without a marked effect.
7. Total carbohydrate content (gig dry weight) was not
greatly affected with most salinity levels at stem elongation
and boating stages, a decline in carbohydrate content
being noticed at boating stage with the application of
either 6000 ppm level or 12000 p)m level. However, the
depressive effect of salinity on carbohydrate content became
more obvious at the heading stage.
8. Protein content (mg/g dry weight) was not affected at
stem elongation stage with the application of 6000- and
8000 ppm tre~tments but tended to decrease with the further
rise-in salinity level. In the boating stage, however, the
rise in salinity level resulted in a gradual and marked
decrease in protein content.” Plants treated ~ith 8000 ppm
level showed on the other hand, a marked rise in their
protein content. At the heading stage, protein content in
plants treated with 6000 ppm salinity level was lower than
that of the control, a tendency for recovery was noticed
however vdth the rise of salinity level.
_. -,’- ..- - ---_.-_ .. _-,. __ .-.~-----
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9. Salinity resulted in a marked accillDulatiunof freeamino
acids content that being more obvious at the stem
elonation stage. The composition of free amino acid pool
of barley shoots exhibited remr:.rkablevariations under
different levels of salinity and growth stages, as well.
The obtained results showee, in general, that salinity had
in most samples a pronouncing effect on raising the proportion
of amino acids that being de}endent on the activity
of Kreb’s cyc~e (K-family), but had, on the other hand,
depressive effect for amino acids derived from triose and
pyruvic acid (TP-family). Among the former group (K),
proline, as a particular recorded a noticeable augment in
their content with salinity •. The increas~ in proline content
was coincided with a marked decrease in glutarric acid.
Aspartic acid was not detected in the free form at any
growth stage; instead, B-alanine composed a marked proportion
that being increased mostly with increasing salinity
level.
10. Gradual accumulation of sodium and chlorides was
clearly shovm in most growth stages with the rise in
salinity level. On the other hand, potassium content was
diminished to some extent at the stem elongation stage with
the application of the lowest salinity level (6000 ppm);
some fluctuations were noticed, however, vdth further rise
in sali~ity level. At the boating stage, however, potassium
level remained more or less stable regardless the rise in
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salinity level up to 12000 ppm level, but being diminished
gradually at the heading stage with the rise of salinity
level. Kg++ content sho~ed in most erowth stages a 2-phase
pattern, so it was diminished Gradually ~ith the rise of
salinity level:”up to 8000 ppm level, then increased to reach
values exceeding those detected in the control ~hen concerning
the rise of salinity level from 8000 to 12000 ppm level
(2nd phase). Despite the increase in salinity level, Ca++
content, however, appeared in most growth stages more or
less similar in the salinized plants but being mostly higher
than that of the unsalinized ones. Data reveal, in addition,
that salinity had not any marked affect on phosphorus
content at the stem elongation and boating stages but being
effective only at the heading stage, at which phosphorus
content recorded gradual increase by increasing salinity
level.
11. Grain analysis reveal that grains produced from plants
treated with 6000, 8000 and 12000 ppm salinity levels were
lower in th~ir carbohydrate content than those untraated.
Vfuereasmore or less similar carbohydrate content to the
control was noticed vath the application of 10000 ppm level.
Protein content in ·.grainsshowed somwhat increase than
the control with the application of 6000 ppm salinity level
only, but showed gradual decline with further rise of
·l
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salinity level.
Na, K and Mg contents increased in grains with the
rise of salinity level. Calcium and phosphorus contents
were not greatly affected in most cases.
The application of low salinity level (6000 ppm), as
being stimulative for protein accumulation in barley grains,
induced at the same time a clear effect on amino acid composition
and appeared different than that exhibited by high
levels of salinity. The application of 12000 ppm salinity
level resulted in a greatly altered protein composition,
since the detected values for the proportion of amino acids
belonging to triose-pyruvic acid family (TP) exceeded those
of Kreb~s cycle. The reverse figure appeared, however,
when concerning unsaline or low salinity levels.
II. Growth Regulators Effects
1. Fresh weight was significantly increased at stem
elongation stage vdth the application of growth regulators
only at the 2nd.season. Kinetin and to less extent Phosphone
were the most effective. Whereas, at boating and heading
stages the stimulative effect of growth regulators on
fresh weight,that detected at both seasons,was more obvious
with the application of Phosphone. Alar, in contrast, was
the least effective. The effectiveness of Kinetin appeared,
---- -- ---------
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however, to be more or less similar to that of benzimidazole
at boating stage but being lower at heading stage.
2. The applied growth regulators exe~ted in most cases
a significant rise in dry weight throughout the growth
period particularly when concerning the 2nd season. Comparatively,
Phosphone and Kinetin proved in most samples to
be the most effective.
J. The effect of growth retardants on plant height
appeared to be contradictory to that shown with cytokinins.
The retarding effect of growth retard~~ts was shovm at both
seasons. Cytokinins, however, exhibited always a significant
increase in plant height in the 1st season; the same
effect was noticed in the 2nd season byt only at heading
stage.
4. Leaf area decreased significantly in both season with
the application of growth -retardants particularly when
concerning later rather than earlier grovah stages. On the
other hand, cytokinins appeared more stimulative at the
earlier than the later stages.
5. Number of tillers was markedly decreased in both
seasons with the application of cytokinins. On the other
hand, growth retardants were without a significant effect.
6. Grain yield per plant was significantly increased in
ibo th seasons wi th the application of growth regulators,
-- -._ .._---~
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particularly Kinetin and Phosphone.
7. Grain weight per spike increased significantly in both
seasons with the application of Kinetin. V~lereas, with
other growth regulators, grain weight/spike was significantly
increased only in the 2nd season.
8. Number of grains per spike increased significantly in
both seasons viith the application of Kine tin and Phosphone.
Alar eL~ibited the same effect at the 1st season only.
Benzimidazole, in this regard, appeared not effective in both
seasons.
9. lOOO-grain weight decreased significantly at the 1st
season with the application of Alar and Phosphone. At the
2nd season, a significant increase on lOaD-grain weight
exhibited by Phosphone and Kinetin. Benzimidazole, however,
had no significant effect on weicht of 1000 groins in both
seasons.
10. The application of growth regulators resulted in
most cases in a lower carbohYQrate concentration (relative
content, mg/g dry weight). Although, at the stem elongation
stage, Phosphone and Kinetin resulted in a slight increase
in the relative content of total carbohydrates. Absolute
content (mg/plant) showed marked increase particularly with
Alar and Kinetin at boating and heading stages. On the
contrary, marked decrease was recorded with Alar and Phosphone
at stem elongation stage and Benzi~dazole at heading
stage.
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11. Crude protein content (relative content) increased
during th€ stem e1o~gation and to less extent at the boating
stages with most the applied growth regulators, but
decreased at heading stage. Absolute content (mg/plant)
increased, however, \nth all growth regulators at boating
stage, but showed some fluctuations with other growth
stages.
12. Free amino acids: a) The application of growth
regulators induced in most growth stages a clear increase
in the content of total free ami~o acids. At stem elongation
stage, the magnitude of such rise appeared greater in
case of Alar but tended to decrease gradually vnth the application
of Prtosphone, Kinetin and Benzimidazole. Alar at the
boating stage was still effective for raising the content of
free amino acids, whereas more enhanced effect was noticed
with Phosphone and Kinetin. The least rise was noticed,
however, vdth Benzimidazole. At the heading stage, however,
the stimulative effect of Alar diminished to great extent,
whereas that of Phosphone, Kinetin and Benzimidazole was
still noticed. b) Data showed, in addition, that the composition
of free ami~o acids ap~eared also to be greatly altered
with the application of growth regulators. In this
regard, the proportion of Kreb’s cycle dependent amino acids
(K) recorded a remarkable increase \uth the application of
Alar at the stem elongation stage only. Such group of amino
acids recorded a similar increase with Phosphone, Kinetin
and Benzimidazole only at the heading stage. The increase
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in the proportion of K-group of a~i~o acids appeared to oe
mainly attributed to t~e increase in the proportion of
B-alanine. On the 0 ther hand, among ami.no acids beloncing
to K-group, glutamic acid showed a marked decrease with
the application of growth regulators particularly at the
stem elongation and boating stages. The reverse effect
proved to be true at the heading stage. Proline e7~ibited
a marked increase only at stem elongation stage with the
a)plica~ion of Alar or Phosphone, whereas the reverse effect
was noticed in the other growth stages particularly with
cytokinins. Proportion of threonine was diminished in most
cases with the application of growth regulators, stimulative
effect was noticed only at the stem elongation stage ~~th the
application of cytokinins. Accordingly, the ratio of a’nino
acids generated from glutamic acid to those generated from
aspartic acid (G/A ratio) was in most cases much lower in
growth-regulators-treated plants. c) In the other direction,
the composition of free amino acids belonging to triosepyruvic
acid family (TP) was also a1 tered ”:,t-hi the application
of growth reguls..tors. The ratio of pyruvic depe.iderrt
amino acids to those of triose (PIT) recorded,vrith most
growth regulators, a remarkable rise at the stem elongation
and boating stages, ~hereas the reverse being true at the
heading stage. The increase in such ratio was attributed
mostly to the increase in the proportion of leucine, alanine
and sometimes valine.
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13. Grein analyses reveal that the application of gr-o.r th
regulators stimulated in most cases the accumulation of
total carbohydrates, whereas the reverse effect was noticed
when concerning protein content. Most of the applied
growth regulators resulted in the reduction of Na content
in grains but being without a~y marked effect on K content.
The content of Ca and Mg increased rnarkedly \rithAlar and
Benzimidazole·unly, but showed unconsistent effect with
other growth regulators.
III. Effects of the interaction betv/een levels of salLli ty
and growth regulators
,1. All growth regulators,in the 2nd season only,
ey~ibited a significant stimulative effect on plant fresh
weight during the boating and heading stages under 1000 and
12000 ppm level of salinity. Similar effects were shown by
phosphone treatment under 6000 and 8000 ppm level at boating
and heading stages.
2. Dry weight/plant was significantly increased at most
growth stages in the 2nd season only with the application
of Phosphone and Kinetin in most salinity levels.
J. Generally, the cytokL:ins, Kinetin and Benzimidazole,
exhibited stimulative effect on plant height under most levels
of salinity in two seasons. On the other hand, growth retardants,
Alar and Phosphone, appeared depressive for plant
height at most levels of salinity.
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4. Leaf area was not significantly affected, in both
seasons, by the interaction between salinity levels and
growth regulators at stem elongation stage. On the other
hand, Alar and Phosphone showed remarkable retarding effect
on leaf area under moderate salinity levels (8000 & 10000
ppm) at boating and headin6 stages. However, cytpkinins
resulted at heading stage only in a significant increase of
leaf area at the high levels of salinity (10000, 12000 ppm)
5. At the 1st season only, cytokinins induced a depressive
effect on ti1lering number under the low salinity
level (6000 p~m) only. Whereas, the reverse behaviour was
observed only with Alar under 8000 ppm level of salinity.
No significant effect has been detected at the 2nd season.
6. Kinetin and Phosphone exhibited stimulative effect on
grain yield/plant under most of the applied salinity levels.
The stimulative effect of Benzimidazole on yield/plant that
has been detected at the 2nd season only appeared to be
exerted under low rather than high salinity levels.
7. At the 2nd season only, Phosphone and Kinetin induced
a stimulative effect on grain weight/spike at most of the
applied salinity levels. Benzimidazole appeared effect~ve
only at 8000 ppm level. Vfuereas,Alar being effective under
10000 ppm salinity level. No significant effect has been
detected at the 1st season.
--- -- ----------------------------- ---
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s. Si~nifica~”1t interaction on grain nur:lber/spike ’::as
schieved only at the 1st season. Phosphone and Kinetin
were efi’ective on rai sing the nuube r of grains/spike at
most levels of salinity. Alar, however, appeared stimulative
at 10000 ppm salinity level oaly. Benzimidazole
appeared without any significant effect. 1000-grain weight
decreased significantly under unsaline conditions with Alar
and Phosphone
9. The relative content of total carbohydrates increased
markedly at stem elongation stage with the application of
Alar and benzimidazole under 10,000 P?m salinity level. Also,
Benzimidazole was still stimulative for carbohydrute accumu-
Laci on at 6000 and 12000 ppm levels. On the other hand,
depressive effect was shovm always with Phosphone and Kinetin
but being detected at 12000 ppm level when concerning Alar.
At the boating stage, relative content of carbohydrates,
showed marked increase vrith most of the applied growth regulators
at 6000 and 12000 ppm levels, whereas the reverse
being true at 8000 and 10000 ppm levels. At the heading
stage, Phosphone appeared enhansi,ve for car-bouydz-a t e accumulation
at most levels of salinity, whereas no consistent
effect was noticed with other growth regulators.
10. The relative content of crude protein that showed
somewhat increase at stem elongation stage with the application
of growth regulators under unsaline conditions, tended
to be counteracted with most levels of salinity. However,
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at the boating stage, growth regulators appeared more
effective in inducing crude protein accumulation under
saline conditions, particularly hioh salinity levels as
compared with their effect under unsaline conditions.
Although, at the heading stage, growth regulators exhibited
some depressive effect under unsaline conditions;
stimulatory effect had been shoym mostly under 6000 &
8000 ppm levels but tended to disappear under other salinity
levels.
11. The ability of growth regulators-treated plants to
accumulate free a~ino acids under unsaline conditions
appeared to be varied greatly with the application of
different salinity levels. In this regard, the applied
growth regulators were still effective for inducing the
accumulation of free amino acids either under the low
or the highest salinity levels. Vlhereas, under moderate
salinity levels (8000 & 10000 ppm), where the accumulation
of free amino acids was more obvious, the application of
growth regulators counteracted, in most cases, the ability
to accumulate free amino acids.
The application of growtt regulators under different
levels of salinity had resulted in a clear regulatory
effect on the compositional characteristics of free amino
acids pool as indicated from the values of the ratios :
Kreb’s cycle dependant amino acids/Triose-Pyruvic-derived
amino”acids (K/TP ratio), Glutamic-generated amino acids/
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Aspartic acid-generated runinoacids (G/A ratio) and Triosegenerated
amino acids/Pyruvic a~td-generated amino acids
(T/P ratio). In this regard, the applied growth regulators
induced at any salinity level a clear enhancement for
raising the K/TP ratio at the stem elongation stage. However,
at the boating stage and heading stage where the
enhansive effect of salinity on K/TP ratio was more obvious,
growth regulators exhibited variable effect according to the
~ype of growth regulators and salinity level, as well. In
the other hand, the effect of 6rowth regulators on G/A ratio
appeared less fluctuated as compared with that noticed under
most levels of saliDity irrespective to tfietype of the
applied growth regulators. The magnitude of such augment in
G/A ratio was ~ore greater with the interaction as compared
with that of salinity or growth regulators separately. In
addition, a clear tendency for raising the ratio; G/A, was
noticed wi th growth advancement reaching, in most cases, t~ie
highest value at the heading stage.
The rise in G/A ratio appeared to be related ~~th the
increase in the proportion of proline particularly under
lower rather than higher levels of salinity. Glutamic acid,
that showed low proportion vdth growth advancement, tended
to be accumulated at the boating stage due to the effect of
growth regulators under most levels of salinity. Concerning
B-alanine, that belonging to aspartic acic group, data reveal
that the applied growth regulators particularly cytokinins
appeared in most growth stages to oe vrith a depressive effect
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at 6000 ppm level, wher-e a.sthe reverse proved ture at the
stem elonation and boating stages.as far as the highest
level of salinity is concerned. However, under moderate
level of salinity (8000 & 10000 ppm) the application of
growth regulators diminished, in most cases, the proportion
of B-alanine, though a somewhat increase was noticed with
Phosphone.
12. Data of the mineral balance reveal that values of
KINa ratio, that showed a substantial decrease with tilerise
of salinity level, tended to be corrected with the application
of growth regulators at 6000 ppm level at the stem elongation
stage as well as under leOOO ppm level at the boating
stage. The reverse effect was shovm, hOTIever, lath other
levels of salinity. On the other hand, marked depressive
effect of growth regulators on KINa ratio was clearly shovm
in most levels of salinity at the heading stage. In addition,.
the ap)lication of growth regulators enzhanced, in most
cases, the rise in the values of Ca+Mg/Na+K ratio at 8000 ppm
salinity level, but being less effective at 10000 and 12000
pm levels. On the other hand, the ap~lication of gro\r.th
egulators at 6000 ppm level tended, to great extent, to
counteract the depressive effect of salinity on K/Ca ratio,
vhereas the reverse being true ~v.itht~herise of salinity
eve1.
13. Grain analyses showed that carbohydrate content in
rains of plants treated with salinity exhibited marked
---~-~ .. _-_... _~~~-
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r€ase, as compared with those of the control, with the
application of Phosphone and Alar. Less effect was noticed,
however with Benzimidazole, whereas no marked effect could
be detected vrhen concerning Kinetin. Protein content
decreased in most cases wi~h the interaction treatments,
but being increased only under 12000 ppm salinity level.
At such high salinity level, Phosphone appeared the most
effective for raising protein content in grains.
Composi tional characteristics of gz-af.n-ep ro t e.Lncanu.no
acids had been greatly altered wi~h the application of growth
regulators under different salinity levels. All the applied
:growth regulato~s were able to enhance the rise of K/TP ratio
under the highest level of salinity, ~hereas any 6f them
xtent under the highest level of salinity (12000 ppm).