In order to study the effect of prime treatment (salt hardening) on maize seeds
(variety Ghouta 82) and type of irrigation water on the plant response to salt stress through
the effect on the productivity and the plant tissue contents Cl, Na and K.
Maize seeds were
soaked in Euphrates fresh water (EC:1.03 dS.m-1), or in agricultural drainage water (EC:
5.89 dS.m-1) for (12) hours, the seeds therefore were dried and planted in plots of (15 m2)
for each replicate and then irrigated with four different types of water; (100 % Euphrates
water, 50% Euph. water + 50% agri. drain. water, 33 % Euph. water + 67 % agri. drain.
water, and 100% agri. drain. water) during the growing season. K, Na, and Cl in plants
were determinated, 1000 grains weight, and grain yield production were estimated in kg.h-1
for each replicate and treatment.
The results showed that, it is possible to have 3 tons of grain / hectare by irrigation
with agricultural drainage water, which is acceptable, under semi-arid conditions. Salt
hardening of maize seeds increased seed yield by (32.80%), which is considered
satisfactory under the experimental conditions.
The effect of salinity and the treatment with fungicide on seed germination of Cupressus
sempervirens L. was investigated.
Five concentrations of salinity (0, 0.5, 1, 5 and 10%) were used. One part of the seeds was
treated with fungicides (Benomyl
), while the other part was germinated without fungicide
treatment. The results showed that seed germination was reduced by salinity, but the reduction was
more pronounced without fungicide and with salt concentration, the seeds didn't germinate at 5 and
10% NaCl.
Despite the decrease of germination indices with the increase of salt concentrations, the
statistical results didn't show significant differences in salinity concentrations and the control in
germination speed without fungicide, but they were significant with the fungicide. The statistical
results showed significant differences between the presence and absence of fungicide in all
treatments
In this study, the effect of different concentrations of sodium chloride
(NaCl) (0, 50, 100, 150 mM) on some physiological characteristics and some
growth indicators of SO4 grape rootstock propagated in vitro was studied at the
laboratories of Gen
eral Commission for Scientific Agricultural Research
(GCSAR), Damascus/Syria. Results indicated that the increase of NaCl
concentration up to 100 mM in culture medium led to reduce the growth
indicators (survival plants, average of the plant length and average number of
buds) with significant differences when compared with the control plants after
4 weeks from culturing on multiplication media, while treatment with 150 mM
of sodium chloride led to death of all plants. Using the concentrations 50 and
100 mM of NaCl also caused decreasing the total chlorophyll content in the
leaves.
This investigation was conducted at the laboratories of Horticulture
Departments, Faculty of Agriculture to study the effect of different levels of
salinity (NaCl) in the rate and the percentage of seed germination of lettuce,
Lactuca sativa L. va
rieties: Shinshar and Kabous and to determine the seedling
response to these levels of salinity with relative to root length, the length of the
cold, fresh and dry weight of seedlings. NaCl was used at 0, 50, 100, 150 and
200 mM/l. Resulted showed that a gradual increase in salinity concentrations
caused a gradual decline in all indicators studied in both cultivars. However,
the plants of Kabous variety were less sensitive to the salinity and also higher
than in the indicators studied for seedlings (rate of germination and percent,
stems and roots length, fresh and dry weight of seedlings) under salt stress
conditions.
The research was conducted on some olive
varieties known as Alsourani- Aldan- Mahazm Abu Satel- Alglet-
Alnepali, in the aim of comparing their tolerance against the stress
of salinity (sodium chloride) through some morphological and
physiological traits. Different concentrations of salt as well as to
the control (fresh water) were used in this experiment.
A hydroponic culture experiment was conducted under the green house
conditions, at the general commission of scientific agricultural research, and
the faculty of agriculture, Damascus university, during the year 2002-003.
The objectives of this in
vestigation concentrated on the influence of four
salinity levels (0-50-100-150 mM NaCl) on some physiological parameters of
eight sorghum genotypes. The experiment was designed in a RCB design with
three replications.
Different experiments were conducted under laboratory conditions, at the
Faculty of Agriculture – Damascus University, in order to develop a suitable
and efficient screening tool, which can be applied to assess the genetic
variability among 20 sor
ghum genotypes (Izraa series) for high salt stress
tolerance.
We were able to develop a screening technique involves pre- exposing
sorghum seedlings to a sub – lethal level of salinity stress (induction stress) (150
mM NaCl) for 16 hrs which can induce the genotypes to prepare defensive
means, which may differ according to the genetic potentiality of each genotype.
These protective responses may help the genotype to endure the lethal level of
salinity stress (400 mM NaCl) for 48 hrs. At a later stage, the seedlings were
transferred to distilled water for 72 hrs and the rate of recovery growth was
taken as a criterion to select the highly salt tolerant genotypes by using Zdistribution
analysis.
Results revealed that genotypes such as: Izraa 10, Izraa 15, and Izraa 18
could be classified as salt tolerant genotypes which showed higher recovery
growth and the least growth reduction over the control. Whereas a genotype
such as Izraa 22 was grouped as salt sensitive one where the percent growth
reduction over the control was greater, indicating that this genotype has low
recovery growth ability.
Our results suggest that the proposed screening technique is rapid, effective,
and match the natural screening.
This investigation is a mimesis to what usually happens in nature, where the
plants are normally exposed to sublethal environmental stresses before their
exposure to the lethal level of stresses.
The gradual increase of environmental stress, gives
plants a suffficient time
to prepare their defensive means to withstand the lethal level of stress. In order
to develope a suitable screening technique, it was essential to determine the
induction as well as the lethal levels of stress, as important components of such
proposed tool.
This technique was applied to screen some tomato genotypes, and assess the
genetic variability among them, in order to evaluate their salinity stress
response , and selecting the highly salt tolerant types.
The study showed that IAA treated cuttings were rooted earlier and bud
development was delayed. On the other hand, IAA treatment increased rooting
percentage and reduced the percentage of bud development. Increasing
NaCl salinity to ٠,١ M decrease
d the rooting ability in cuttings, while the
use of IAA could mitigate the adverse effect of salinity. The best results of
rooting were obtained in treatment of (٠,٠٥ M).
