الفهرس 
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Abstract
Two pot experiments were conducte III the green-house of the
National Research Centre, Dokki, Giza it 1996 and 1997 growing
seasons to study the effect of some growth r gulators and irrigating with
different levels of salinized water on growth, orne physiological aspects.
yield and seed constituents of sunflower cv, y-sun,
Each experiment included 21 tr atments which were the
combinations of three levels of salinized wate (0, 3000, 6000 ppm) in the
form of chloride type and seven growth r gulator treatments as seed
soaking in 10, 20 % Polyethylene glycole ( smotic stress) for 24 hours,
Paclobutrazol (PBZ) and Uniconazole (Uni .) (growth retardants) of 10,
20 ppm for each for 5 hours. in addition to ontrol treatment (untreated)
seeds.
Treatments were arranged in rando ’zed complete block design
system in 10 replicates. The obtained res ts could be summarized as
follows:
I. Effect of salinity:
1. Germination percentage:
Salinity significantly decreased ermination percentage of
sunflower seeds. The reduction was more su stantial under 6000 ppm and
the percentage of depression was 24.3 % as c mpared with the control.
2. Vegetative growth characters:
Salinity tended to decrease signific ntly different characteristics
of plant growth represented in plant heig t, number and area of green
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leaves as well as dry weight of leaves, stern, head and the whole plant
compared with control treatment (irrigation ith normal water). Salinity
caused an increase in leaf thickness repres uting in decreasing S.L.A.
(cmvg.)
3. Photosynthetic pigments content:
Salinity tended to increase photosyntl etic pigments slightly as
chlorophyll a, chlorophyll b and carotenoid content in sunflower plant
leaves under both 3000 and 6000 ppm sa inity level. Also, salinity
increased tile ratio of total chlorophyll a + b carotenoids, but decreased
tile ratio of chlorophyll alb.
4. Stability of chlorophyll-protein-Iipid co plex:
Increasing salinity level up to 300 ppm tended to decrease
stability of chlorophyll in tile tissues of s nflower plant leaves. The
decrease was much more when salinity lev I increased to 6000 ppm
compared with control treatment.
5. Cell sap concentration and proline con ent :
Cell sap concentration (T.S.S.) and 0 motic potential as well as
proline content were increased by increasin salinity level. The rate of
their increase was according to the level of sali ity in water of irrigation.
6. Yield and its components:
Irrigating sunflower plants with s line water significantly
decreased head diameter, head weight, seed yi Id/plant, shelling %, 1000
seed weight (seed index) as well as oil yield/pi- t. Salinity reduced head
weight by 20.3 and 40.2 %, seed yield/plant y 33.3 and 51.1 % and oil
yield by 48.5 and 65.3 % under 3000 and 6000 ppm salinity level,
respectively as compared with the control.
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7. Oil, Protein and carbohydrates content:
Saline water decreased the concentration 01 oil percentage as well
as protein % in sunflower seed tissues com ared to irrigation with
nOllnal water. However, soluble and total -arbohydrates % were
increased by increasing salinity level and the ·ate of increasing was
substantace as salinity level raised up to 6000 ppt
8. Nitrogen, potassium and sodium contents
Total nitrogen in sunflower seeds dec eased as salinity level
increased in water of irrigation up to 6000 pp . potassium and sodium
concentrations as well as NaiK eased in sunflower seed
tissues as salinity level increased in root mediu
9. Fatty acids concentration:
Increasing salinity level in the water irrigation to 3000 ppm
decreased palmitic acid concentration in sunflo er oil, but it increased as
salinity level increased up to 6000 ppm. Oleic id, however, behaved in
an opposite manner, where it increased by increasing salinity level.
Linoleic acid concentration linearly decreased a salinity level increased.
n. Effect of growth regulators:
1. Germination percentage:
Paclobutrazol (PBZ) and Uniconazole ( nic.) under the two tested
concentrations (10 and 20 ppm) as well as 20 % polyethylene glycole
(PEG) as osmotic stress significantly nhibited the germination
percentage. However, soaking seeds in 10% ’EG significantly increased
gennination percentage.
2. Vegetative growth characters:
Soaking sunflower seeds pre-sowing in ei ier uniconazole (Uuic.)
or paclobutrazol (PBZ) at both concentrations exhibited remarkeable
.effect on decreasing plant height as well as dry eight of different plant
organs. The effect was significant for all of th studied developmental
plant stages. The rate of. decreasing was incr ased as concentl’ation of
growdl retardants increased. However, Polyethy ene glycole (PEG) at the
concentration of 10 and 20 % significantly i reased plant height and
total dry weight at all of the studied plant stages.
Generally all seed soaking treatments aused an increase in leaf
thickness representing in decreasing S.L.A. and af area/plant.
3. Photosynthetic pigments content:
Soaking sunflower seeds pre-sowing ill either PBZ or Unic.
solutions tended to increase photosynilietic p gments as chlorophyll a,
chlorophyll b and conseqeuntly total chlorop yll as well as carotenoids
content in plant leaves. However, the highe t concentration (20 %) of
PEG decreased both green and orange pigment .
4. Stability of chlorophyll-proteiD-lipid co plex:
Both PBZ and Unic. growth r tardants with their two
concentrations tended to increase stability , f chlorophyll-protein-lipid
complex in sunflwoer plant leaves. Treatm nt with 20 % PEG gave the
lowest value of chlorophyll stability.
5. Cell sap concentration and proline con ent :
Soaking sunflower seeds pre-sowin’ in any of tested growth
regulator tended to inc;;reasethe accumulatio of proline in leaf tissues as
well as the cell sap concentration and osmoti potential.
6. Yield and its components:
All soaking treatments in growth regula rs solutions recorded
higher values 111 yield and its components than untreated one.
Uniconazole at 20 ppm surpassed all of the ther treatments as for
increasing head diameter, head weight and see yield/plant followed by
10% PEG and 10 ppm Unic. treatments.
7. Oil, Protein and Carbohydrates content:
Soaking sunflower seeds pre-sown in eith riO % PEG or 10 or 20
ppm Unic. tented to increase oil percentage sightly. However, protein
percentage as well as soluble and total carbo ydrates increased due to
soaking seeds in all of the tested growth reg lator solutions compared
with those of untreated ones.
8. Nitrogen, potassium and sodium contents:
Growth regulators tended to increase nitrogen, potassium and
sodium in seed tissues. However, they caus reduction in Na/K ratio
compared with untreated seeds.
9. Fatty acids concentration:
The lowest ratio of oleic/linoleic was recorded when using
20% PEG (the best one). Also the lowest ra io of saturated/unsaturated
fatty acid ratio was obtained from soaking see in 10% PEG.
III. Effect of the interaction between salnity levels and growth
regulators:
J. Germination percentage
Soaking seeds in J 0 % PEG solu ion tended to increase
gennination percentage significantly under i igation with normal water
or 3000ppm salinity level. However, the inc ’ease was not significant
under 6000 ppm level of salinity. Generally, a Itested growth retardants
as PBZ and Unic. reduced germination per entage under all salinity
levels.
2. Vegetative grwoth characters:
All growth retardant treatments d reased plant height, dry
weight of all plant parts as well as the area f leaves, except that of 20
ppm Unic. which surpassed control treatme t. These results were hue
under 3000 and 6000 ppm levels of salinity at oth budding and flowering
stages, while soaking seeds in 10% PEG si ificantly increased plant
height and dry weight of whole plant under 000 and 6000 ppm salinity
level and insignificantly increased leaves ea under both levels of
salinity at flowering stage.
3. Photosynthetic pigments content:
At vegetative growth stage, soaking eeds in either 10 or 20 %
Unic. and irrigated with 3000 or 6000 ppi salinized water formed the
highest photosynthetic pigments content. H wever, at budding stage, 20
ppm Unic. combined .with 6000 ppm salin ty level surpassed all of the
other interactions as for increasing chl.a, cl I. a+b and carets. compared
with the other interactions. AI flowering slag soaking seeds in any of the
tested growth regulators as PEG. PBZ and Unic. increased total
chlorophyll (a+b) compared with untreated sods.
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4. Stability of chlorophyll-protcin-lipid COl plex:
The most promising interaction for increasing stability of
chlorophyll was when seeds soaked in 10 pp Unic. and irrigated with
normal water. 20 % PEG tended to decrease s ch paramters under 3000
and 6000 ppm level of salinity.
5. Cell sap concentration and proline cont nt:
Soaking seeds in any of the tested gro regulator as PEG, PBZ
and Unic. solution at the two concentra ions increased cell sap
concentration as well as prolien content in leav s under all salinity levels.
Proline content increased with increasing bo salinity level and growth
regulator concentrations.
6. Yield and its components :
Under irrigation with normal water, soaking seeds in 20 ppm
Unic. significantly increased both seed and 0 I yield/plant. The treatment
of 10 % PEG recorded the highest seed inde . Under 3000 ppm salinity
level, 10 % PEG recorded the highest seed d oil yield/plant as welI as
seed index. However, under irrigation with 6 00 ppm salinized water, 20
ppm Unic. gave the highest seed and oil y eld, but seed index was the
highest due to 10 ppm Unic. treatment under t e same salinity level.
7. Oil, Protein and Carbohydrates conten
Generally 1soaking seeds in any of e tested growth regulator
tended to increase oil percentage slightly un er irrigation with 3000 and
6000 ppm salinity level. Such increase was nore obvious as for protein.
soluble and total carbohydrates percentage co pared with untreacd seeds.
8. Nitrogen, sodium and potassium cnnc ntrations :
Under saline condition, soaking see s in solutions of the tested
growth regulators increased nitrogen, sodinm and potassium
concentrations. However, it decreased the rati of Na/K compared with
the untreated seeds.
9. Fatty acids concentration:
Soaking seeds in 20 % PEG gave the higl est value of linoleic acid
under 3000 ppm salinity level. However, 10% PEG treatment increased
the unsaturated fatty acids: Under 6000 ppm Ie el of salinity, 10% PEG
recorded the highest value of linoleic acid, while 10 ppm Unic. caused the
highest concentration of the unsaturated fatty aci .