Salt stress reduced the germination capacity, the root and shoot lengths, the production of fresh and dry matter, and the water content in sorghum (sorghum bicolor L.) seedlings. This reduction was concomitant with a decrease in the contents of soluble proteins, free amino acids and nucleic acids (RNA and DNA), while proline and quaternary ammonium compounds (qacs) increased, especially at low and moderate (50 and 100 mM NaCl) salinity levels. Pre-soaking sorghum grains in either cytokinin or gibberellic acid (GA3) partially or completely counteracted the adverse effects of salinity on the rate of germination, seedling growth and some metabolic mechanisms. Generally, exogenous applications of cytokinin or GA3 enhance the metabolic processes of sorghum plants and improve their tolerance to salt stress.
The effect of different concentrations of salinity (NaCl up to 250 mM) was studied on the germination, dry matter production and some relevant metabolic parameters of two lines (Sakha 69 and Sakha 164) and one variety (Stork) of wheat (Triticum aestivum L.). During the germination and seedling stages the experimental lines tolerated lower and moderate doses of salinity, while the variety was significantly retarded at the lower and moderate levels and completely inhibited at higher doses of salinity. The water content remained more or less unchanged in the two lines under saline conditions, whereas in Stork increasing salinity resulted in a significant decrease in water content. A stimulation of the net photosynthetic rate in both lines, Sakha 69 and Sakha 164, was observed at moderate salinity, but the highest levels proved to be inhibitory. In the Stork variety all salinization levels inhibited photosynthetic activity. The respiration rate in the two tested lines was influenced from salinity levels of 150 mM upwards and increased progressively with the salinity level. In Stork plants increasing salinity levels increased the respiration rate. The soluble sugar and soluble protein contents of the lines increased with increasing salinity. The opposite pattern was revealed in the case of Stork. The amino acid content, including proline, increased significantly with an increase in salinity in all tested plants. the potassium/sodium ratio decreased significantly with a rise in salinization.
Authors:M. M. Heikal, A. M. Ismail and M. M. Azooz
Salinity adversely affected the photosynthetic pigment biosynthesis and carbohydrate fractions in two broad bean lines, 67 and 13. The accumulation of proline and other amino acids was also altered. The interactive effects of salinity and exogenous treatments with vitamin pyridoxine (B6) on these parameters were also tested. These treatments included soaking the seeds or spraying the shoots with vitamin solution. The vitamin treatments generally counteracted the adverse effects of salinity. The importance of these treatments to the salinity tolerance of broad bean lines is discussed.
Authors:M. Ismail, M. Ali, A. El-Milligy and M. Afifi
The effect of impregnation time on the physico-chemical and mechanical properties of polyester-cement mortar composite has
been investigated. The samples were soaked in unsaturated polyester resin containing 40% styrene monomer at impregnation times
ranging from 1–15 hours and then exposed to 50 kGy of γ-irradiation. The effects on polymer loading, compressive strength,
apparent porosity, and water absorption in addition to IR spectra and TGA of the samples were studied. It was found that,
the polymer loading and compressive strength increase with the increased of soaking time up to 4 hours and there is no significant
improvement of the polymer loading and compressive strength increase with the increased of soaking time up to 4 hours and
there is no significant improvement of the polymer loading and strength. Whereas, the apparent porosity and water absorption
behave in an opposite direction. These are attributed to the presence of polymer in the pores of the samples. IR spectra showed
that, new bands appeared as result of the reaction between polyester and set cement. TGA showed that, the polyester cement
composite has higher thermal stability as a compared to irradiated polyester.
Authors:M. M. El-Araby, S. M. A. Moustafa, A. I. Ismail and and A. Z. A. Hegazi
Seeds of tomato (Lycopersicon
esculentum Mill., variety Castle rock)
were osmoprimed in polyethylene glycol 6000 (PEG; 20%) or K2HPO4
(200 mM) solution for 8 hours, 3 days or 7 days, while another group of
seeds were left in water for the same periods. The GA3/ABA ratio was
the most important hormone factor, which promoted germination in seeds soaked
in H2O and led to improved germination performance. This ratio
showed slight variations between hydroprimed and osmoprimed seeds after 8
hours, but afterwards, from 3 to 7 days, it was gradually increased in the
osmoprimed seeds and was substantially elevated in seeds germinating in H2O.
Changes in the concentrations of phenolic compounds suggested their possible
role in germination silencing in the osmoprimed seeds, but at relatively low
concentrations. Protein patterns showed no marked variations in hydroprimed and
osmoprimed seeds after 8 hours, but different types were observed, particularly
after 7 days. A comparison of the protein banding patterns of seeds after 1 day
and 7 days in the osmoconditioning solutions (PEG or K2HPO4),
H2O, GA3 or ABA showed certain treatment-specific protein
bands, particularly in PEG and ABA solutions. Longitudinal sections of seeds
(after 3 days) showed lysis of the micropylar endosperm and radicle protrusion
in H2O or GA3, whereas in PEG or K2HPO4
solution the radicle expanded inside the seed and the micropylar endosperm was
completely intact. In ABA solution, the whole endosperm was compact and the
seed became extensively desiccated.
Authors:K. El-Azony, M. Ismail Aydia and A. El-Mohty
Triton X-100 cerium(IV) phosphate (TX-100CeP) was synthesized and characterized by using IR, X-ray, TGA/DT and the elemental
analysis. The chemical stability of TX-100CeP versus the different concentrations of HCl acid was studied before and after
its exposure to the radiation dose (30 K Gray). The effect of HCl concentration on separation of Cr(III) from Cr(VI) by using
TX-100CeP as surface active ion exchanger was also studied. A novel method was achieved for the quantifying of Cr(III) and
Cr(VI) ions by using the high-performance liquid chromatography (HPLC) at wavelength 650 nm, a stationary phase consists of
reversed phase column (Nucleosil phenyl column; 250 × 4.6 mm, 5 μm), and a mobile phase consists of 0.001 M di-(2-ethylhexyl)
phosphoric acid (DEHPA) in methanol:water (70:30 v/v). The retention times were 7.0 and 8.5 min, for the Cr(III) and Cr(VI),
respectively. The exchange capacity of Cr(III) was quantified (2.1 meq/g) onto the TX-100CeP.
222Rn concentrations were measured in 50 dwellings in Celein region, west of Al Khums city in Libya. Time-integrated passive
radon dosimeters containing CR-39 detectors were used in this study. The measurements were done in living and bedrooms for
each dwelling. After 3 months detectors were collected. Then, applying chemical etching to the exposed detectors, nuclear
track numbers and corresponding indoor radon concentrations were determined. The arithmetic mean is 76.1 ± 49.4 Bq m−3 and the geometric mean is 63.8 Bq m−3 with a geometric standard deviation of 1.8. Data distribution is well fitted by a log-normal curve. The fractions of rooms
where radon concentrations exceed the reference levels of 148 Bq m−3 is 7.8%. Risk of lung cancer ranges from 4 to 32 per thousand dwellers for nonsmokers and smokers respectively.
Authors:M. Ismail, M. El-Fass, H. Abd-El-Rahman and A. El-Milligy
The influence of methyl metharcylate and gamma exposure dose on the physico-chemical and mechanical properties of polymer-alite
composite have been investigated. The hardened alite samples were impregnated with a methyl methacrylate monomer and then
subjected to γ irradiation doses from 10–50 KGy. The effect of polymer loading (%), compressive strength, bulk density and
the microstructure (scanning electron microscopy SEM), in addition IR spectra were studied. The results indicate that, polymer
loading, compressive strength and bulk density increase with increasing absorbed dose. This is attributed to the deposition
of the polymer in the pores of the samples. SEM showed the voids between the particles in the samples before the impregnation,
whereas, the formation of new products in the pores appeared after impregnation.
Authors:S. L. Krishnamurthy, S. K. Sharma, D. K. Sharma, P. C. Sharma, Y. P. Singh, V. K. Mishra, D. Burman, B. Maji, B. K. Bandyopadhyay, S. Mandal, S. K. Sarangi, R. K. Gautam, P. K. Singh, K. K. Manohara, B. C. Marandi, D. P. Singh, G. Padmavathi, P. B. Vanve, K. D. Patil, S. Thirumeni, O. P. Verma, A. H. Khan, S. Tiwari, M. Shakila, A. M. Ismail, G. B. Gregorio and R. K. Singh
Genotype × environment (G × E) interaction effects are of special interest for identifying the most suitable genotypes with respect to target environments, representative locations and other specific stresses. Twenty-two advanced breeding lines contributed by the national partners of the Salinity Tolerance Breeding Network (STBN) along with four checks were evaluated across 12 different salt affected sites comprising five coastal saline and seven alkaline environments in India. The study was conducted to assess the G × E interaction and stability of advanced breeding lines for yield and yield components using additive main effects and multiplicative interaction (AMMI) model. In the AMMI1 biplot, there were two mega-environments (ME) includes ME-A as CARI, KARAIKAL, TRICHY and NDUAT with winning genotype CSR 2K 262; and ME-B as KARSO, LUCKN, KARSA, GOA, CRRI, DRR, BIHAR and PANVE with winning genotypes CSR 36. Genotypes CSR 2K 262, CSR 27, NDRK 11-4, NDRK 11-3, NDRK 11-2, CSR 2K 255 and PNL 1-1-1-6-7-1 were identified as specifically adapted to favorable locations. The stability and adaptability of AMMI indicated that the best yielding genotypes were CSR 2K 262 for both coastal saline and alkaline environments and CSR 36 for alkaline environment. CARI and PANVEL were found as the most discernible environments for genotypic performance because of the greatest GE interaction. The genotype CSR 36 is specifically adapted to coastal saline environments GOA, KARSO, DRR, CRRI and BIHAR and while genotype CSR 2K 262 adapted to alkaline environments LUCKN, NDUAT, TRICH and KARAI. Use of most adapted lines could be used directly as varieties. Using them as donors for wide or specific adaptability with selection in the target environment offers the best opportunity for widening the genetic base of coastal salinity and alkalinity stress tolerance and development of adapted genotypes. Highly stable genotypes can improve the rice productivity in salt-affected areas and ensure livelihood of the resource poor farming communities.