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| Articles
by
Samira R. Mansour |
Total Records (
3 ) for
Samira R. Mansour |
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Abdel-Raouf
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A. Moustafa
and
Samira R. Mansour
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The present study aimed to establish Acacia tortilis seedlings with a minor amount of water through improving the soil physical properties by adding different soil conditioners during the early growth stages of Acacia. Three soil conditioners were added to the soil holes in the field before transplanting; gel, organic matter and a mixture of both. Four hundred Acacia tortilis seedlings at the same age and height were transplanted in the field on different treatments and many vegetative parameters were used to measure the growth rate of the seedlings. These parameters included shoot height, number of compound leaves, vitality, water content of both shoot and root system, number of lateral roots and both length and width of the root system. Results showed that seedlings transplanted on soil enriched with gel produced the highest values of leaflets, shoot height, vitality, width of root and water content of both shoot and root system and the lowest values in root length. While the mortality rate were very low for the seedlings cultivated on gel-enriched soil, it was the highest for seedlings cultivated on the organic matter-enriched soil and soil enriched with mixture of both gel and organic matter. |
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Samira R. Mansour
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Some factors affecting the
establishment of Casuarina-Frankia
symbioses were studied by following the survival of some Frankia strains exposed to different environmental soil
conditions. This was accomplished by examining the effect of soil desiccation
at 30oC temperature or to intermittent exposure of desiccated soil
to 50oC (3h on three consecutive days) and different soil pHs on
nodulation. Six Frankia strains
were isolated from different Casuarina
plantations and were used in this study. Frankia
survival, was measured as the persistence of nodulation capacity using the
plant infection technique. The survival of introduced Frankia fell markely in soils undergoing drying. The extent of
decline varied with strain and soil. The decrease in numbers for all strains
after desiccation was greater in reclaimed soil than other soils tested. The
survival of all Frankia strains in
response to desiccated soil was higher with intermittent exposure to 50oC
than when desiccated at 30oC. The survival of introduced Frankia varied with adjusted soil pHs.
Survival was often higher at pH 8, but usually was adversely affected by
higher pH (pH 8.5). Recovery of introduced Frankia into autoclaved soils, exposed to different treatments,
was significantly higher than non-autoclaved soil. |
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Samira R. Mansour
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Antibiotics Penicillin G and Rifamycin were screened for their effect on morphology, growth and
infectivity of two Frankia strains CeI5 and R43. Rifamycin at concentration 10µg ml-1 was found to
produce morphological changes and alternation in infectivity of Frankia strain R43. Penicillin G showed
no effect at the same concentration and had inhibitory effect at higher concentrations as Rifamycin. |
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