الفهرس 
LITERATURE REVIEWOnly 14 pages are availabe for public view
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Abstract
Our study revealed that about 59 plant species collected from North Sinai area, it was found that
53 plant species had arbuscular mycorrhizal fungi and 6 plant species were non mycorrhizal. Most
cultivated plant species were infected with mycorrhizal fungi. Some field crops were heavily
infected by AM fungi e.g. Olea europea, Psdium guajava, Allium sativum, Lactuca sativa, Coriandrum
sativum, Foeniculum vulgare, Prunus amygdalus and Medicago sativa. Some species from the survey
were considered as non-mycorrhizal where they appeared to be incompatible towards mycorrhizal
fungi. These include Malva parviflora, Ammophila arenaria, Acacia sa ligna, Nitraria
· retusa, Zygophyllum coccineum and Salvia controversa.
There was no obvious relationship between soil extracted spores’ number of AM and percentage of
mycorrhizal infection of plant roots of the surveyed samples. Furthermore, the spores were
generally absent in soils of non-mycorrhizal plants. All the soils collected during this study were
sandy or sandy loam and slightly alkaline. Soil samples which had high levels of organic matter
had high spore numbers.
According to the recent keys of identification, the spores collected belonged to the following
genera: Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe, Glomus clarum (Nicolson & Schenck),
Glomus monosporum (Gerdemann & Trappe), Glomus caledonium (Nicol. & Gerd.) Trappe, Gigaspora
margarita (Becker & Hall), Acaulospora laevis (Gerdemann & Trappe).
Spores number had a modest positive correlation with soil organic matter and actinomycetes count.
Non-significant correlations appeared between the spores’ number of the
examined soils and infection%, available P, salinity level, fungal count, bacterial count, soil pH
and soil CaC03 .
In this study, a pot experiment was carried out to evaluate
the changes of growth criteria, photosynthetic pigment, main metabolites ·concentration, some water
relations and some enzymes activity in tillering, booting and anthesis stages of wheat plants
irrigated with under ground saline water. Furthermore, polyamines level was also investigated in
the anthesis phase. The following results were obtained:
1- Salinity stress significantly reduced shoot fresh and dry
weights of wheat plants at all evaluated growth stages. Furthermore, increasing the salinity level
increased these adverse effects. Mycorrhizal inoculation, spermine treatment and their combination
significantly increased shoot fresh and dry weights of wheat plants in relation with non
mycorrhizal (NP) plants. In this respect the dual treatment with VAM and spermine was more
efficient than in case of each alone.
2- Salinity stress significantly reduced root fresh and dry weights of wheat plants at studied
growth phases. Mycorrhizal infection either alone or in combination with spermine decreased the
root fresh weight of wheat plants as compared with non VAM plants, but the spermine treatment
significantly improved the root weight. Mycorrhizal inoculation treatments either alone .or in
combination with spermine decrease the ratio of root/shoot.
3- Shoot length, total leaf area, specific leaf area, of wheat plants significantly reduced by
salinity stress at all evaluated growth stages. AM infection either alone or in combination with
spermine significantly increased these parameters in relation with non VAM plants.
4- Chlorophyll”a”, Chlorophyll”b”, carotenoids and total pigments level was significantly decreased
in wheat leaves in response to salinity stress at all studied growth phases. Mycorrhizal
inoculation, spermine and their combination treatments improved Chlorophyll”a”, Chlorophyll”b”,
carotenoids and total pigments.
5- Salinity stress markedly decreased polysaccharides content
of wheat plants and significantly increased sucrose and total soluble sugars at all studied growth
stages. Additionally, this effect increased with increasing the salinity level. The main effect
of mycorrhizal infection, spermine and their combination was to increase the polysaccharides level,
sucrose and total soluble sugars of the used plants as compared with non mycorrhizal plants.
Moreover, the VAM fungi either alone or in combination with spermine appeared to add more increase
than the spermine alone
6- Mycorrhizal infection, spermine and their combination significantly increased the protein
concentration of wheat plant grown in control or stress conditions as compared with non VAM (NP)
plants. In this direction, the combination treatment (VAM + spermine) induced more increase in
protein content than the mycorrhizal treatment, which exhibited more increase than the spermine
treatment. Salinity stress markedly increased free proline and protein concentrations in wheat
leaves as compared with control plants, but the increase in protein content greatly reduced under
high salinity levels (6800 ppm).
7- In general, moderate salinity stress (4900 ppm) greatly increased the total nitrogen of wheat
shoot and root tissues, but decreased with high salinity levels. Mycorrhizal combination
(VAM+Spm) and mycorrhizal treatments
alone significantly improved nitrogen uptake of wheat plants. Also, spermine treatments increased
nitrogen uptake, but less than the mycorrhizal ones at low salinity levels.
8- Phosphorous, potassium content and K+INa+ ratio of
salinity stressed wheat leaves and roots were greatly reduced and sodium content was increased at
all growth stages. This effect increased with increasing salinity level. Mycorrhizal fungi,
spermine and their combination treatments significantly increase the total P, K+INa+ ratio and
potassium levels, but decrease sodium content of wheat leaves and roots in relation with non
mycorrhizal (NP) plants.
9- Mycorrhizal inoculation, spermine treatment and their
combination treatments significantly reduced the E.L. and greatly increased RWC of wheat leaves in
relation with non VAM (NP) plants under non saline and saline conditions. On many occasions, the
VAM plants had a lower E.L. than the non VAM plants. These results indicated that the mycorrhizal
fungi mitigated the detrimental effect of salinity on wheat plants at least partially by reduction
of the electrolyte leakage.
10- Salinity stress reduced acid and alkaline phosphatases activity of wheat roots, while induced
more peroxidase and a- amylase enzymes in leaves, this effect was increased with increasing
salinity level. In all treatments, the soluble acid phosphatase activity was much higher than
the alkaline phosphatase activity. Mycorrhizal inoculation, spermine and their combination
treatment (VAM + spermine) greatly improved the soluble acid & alkaline phosphatases, a- amylase
and peroxidase activities of
wheat roots as compared with non-mycorrhizal wheat plants. J
ll-Spermidin’t1spermine contents of wheat leaves were
decreased, while putrescine content and estimated putrescine/ (spermidine+ spermine) ratio was
increased in wheat leaves in response to salinity stress. Under salinity stress as well as control
conditions, mycorrhizal infection, spermine and their combination significantly decreased the
putrescine content and the estimated putrescine/ (spermidine+ spermine) ratio, and increased
spermine and Spermidine levels of wheat plants as compared with non VAM (NP) plants.
The intensity of mycorrhizal infection of wheat roots was significantly higher in inoculated plants
as compared with non inoculated wheat plants at all evaluated growth stages. No mycorrhizal
colonization was observed in uninoculated wheat plants. The imposed salinity stress significantly
decreased the mycorrhizal colonization of wheat roots and the effect was more elicited with the
highest salinity level. On the other hand, combination of spermine with inoculation of wheat roots
by VAM fungi leads to a significant improvement of mycorrhizal colonization at all evaluated growth
stages.
At yield stage of wheat plants, salinity stress significantly reduced the length of wheat spikes,
shoot dry weight, grain yield, grains number, grain biomass and harvest index, and the effect was
more pronounced in the case of high salinity (6800 ppm). Under stress conditions, the mycorrhizal
inoculation, spermine and their combination significantly improved these parameters of used plants
as compared with non VAM (NP) plants. The combination treatment (VAM+spermine) exhibited a better
effect than mycorrhizae and spermine each alone.
The imposed salinity stress significantly decreased total carbohydrates and proteins level, while
increased lipids and ash contents of the developed wheat grains and this effect increased with
increasing salinity level. In control as well as. stress conditions, mycorrhizal infection,
spermine and their combination significantly increased these contents of wheat grains as compared
with those of non VAM (NP) plants. On most occasions, the combination treatment induced more
increase in these substances than mycorrhizal treatment which in turn exhibited more increase than
the spermine treatment.