Effects of humidity and light conditions /fluoroscent light, sunlight and diffuse sunlight/ on the response of 2 mm thick clear polymethylmethacrylate /PMMA/ dosimeter during irradiation and during postirradiation storage were determined spectrophotometrically at 305 and 314 nm. The results showed that irradiation of dosimeters at 12–97% relative humidity did not result in any change in the response upto 2 weeks of post-irradiation storage. However, there is some decrease in the response at higher humidities />76%/ for longer storage time. Post-irradiation storage and dosimeters at constant relative humidity conditions between 35 and 97% had no effect on the response up-to 3 weeks. Post-irradiation storage at lower relative humidity /12%/ showed some decrease in the response for longer periods. The response of dosimeter is not very sensitive to short time exposure to diffuse sunlight and fluorescent light. However, a significant increase in the optical density was observed during exposure of dosimeters to direct sunlight.
Studies were conducted to measure the effect of irradiation treatment on thermoluminescence (TL) values in dried fruits such
as apricots, dates and raisins. For this purpose, inorganic dust particulate (minerals) adhering to the fruit surface was
collected from untreated and treated (0.5, 1.0 and 1.5 kGy) samples. The TL responses of the isolated minerals was measured
in the temperature range of 80–320°C at an increasing rate of 10°C/s. It was observed that peak of the TL signals appeared
at 200°C in each case and generally the magnitude of the peak signals was almost 103 times that of unirradiated samples. Regression and correlation analysis of the data indicated strong relationship between
radiation absorbed dose and TL values at each temperature (r≥0.98). It was concluded that TL measurements could serve as a fast and reliable method for distinguishing as well as determining
absorbed dose in irradiated dried apricot, date and raisin.
Authors:Hasan Khan, Gulzar Ahmad, A. Sattar and S. Durrani
Some plastic sheets manufactured or commercially available in Pakistan have been tested as radiation dosimeters for cobalt-60 -rays. Radiation induced colouration in the plastics have been measured spectrophotometrically. The results show that 2 mm thick clear poly(methyl methacrylate) (PMMA) can be used as radiation dosimeter up to 45 kGy when absorption measurements are made at 305 nm and 314 nm; whereas 1 mm thick clear poly(vinylchloride) (PVC) is useful up to 30 kGy when measured at 396 nm. The response of PMMA dosimeter is stable for at least 15 days and that for PVC for 30 days, when stored under ambient conditions after irradiation. Post-irradiation stability at various temperatures (–10 to 55°C) has also been studied.
Authors:T. Ahmad, A. Sattar, S. Atta, A. Zeb, A. Ahmad and S. A. Nagra
Rapeseed oil was used for frying of potato fillets (French fries) for 4 consecutive days at a rate of 20 minutes per day. The quality constants such as peroxide value (POV), anisidine value (AV), free fatty acid polar compounds (FFA%) and colour index (as OD at 420 nm) were determined before and after frying. The results showed an increasing pattern in the values of quality parameters. The POV increased from 4.42 to 17.00 meq kg-1, AV from 8.37 to 65.60, FFA from 0.02 to 1.90% and colour (absorbance at 420 nm) from 0.16 to 2.20. Fried rapeseed oil was mixed separately with 3 levels of MgO (2, 4 and 6% w/w) and activated charcoal (2, 6 and 10% w/w). For all the treatments the average % improvement of quality indices was statistically analysed. Increasing levels of both activated carbon and MgO significantly affected (P<0.05) the different quality parameters tested so far.
Authors:A. Sattar, M.A. Cheema, T. Abbas, A. Sher, M. Ijaz, M.A. Wahid and M. Hussain
Late planting of wheat in rice-wheat cropping system is perhaps one of the major factors responsible for low crop yield. The main cause of reduction in yield is due to supra-optimal conditions during the reproductive growth. High temperature during reproductive phase induces changes in water relations, decreases photosynthetic rate, and transpiration rate, stomatal conductance and antioxidative defence system. Silicon (Si), being a beneficial nutrient not only provides significant benefits to plants growth and development but may also mitigate the adversities of high temperature. A field study was conducted at Agronomic Research Area of University of Agriculture; Faisalabad, Pakistan to assess the performance of late sown wheat with the soil applied Si. Experiment was comprised of three sowing dates; 10th Nov (normal), 10th Dec (late), 10th Jan (very late) with two wheat varieties (Sehar-2006 and Faisalabad-2008), and an optimized dose of Si (100 mg per kg soil), applied at different growth stages (control, crown root, booting and heading). Results indicated that 100 mg Si per kg soil at heading stage offset the negative impact of high temperature and induced heat tolerance in late sown wheat. Silicon application improved 34% relative water contents (RWC), 30% water potential, 26% osmotic potential, 23% turgor potential and 21% photosynthetic rate, and 32% transpiration rate and 20% stomatal conductance in wheat flag leaf than control treatment. Further it was observed that Si application preventing the oxidative membrane damage due to enhanced activity of antioxidant enzymes, i.e. 35% superoxide dismutase (SOD) and 38% catalase (CAT). In conclusion results of this field study demonstrated that soil applied Si (100 mg per kg soil) at heading stage enhanced all physiological attributes of wheat flag leaf. Which in turn ameliorated the adverse effects of high temperature in late sown wheat. Study depicted that Si can be used as a potential nutrient in order to mitigate the losses induced by high temperature stress.
Authors:A. Samad, P. V. Ajayakumar, M. Zaim, A. Sattar and A. Khaliq
Phytoplasma-induced yellows, little leaf, proliferation of axillary shoots, rosetting and over all retarded growth of infected plants were found in the experimental fields of Phyllanthus amarus (P. niruri) at CIMAP, Lucknow in 1999-2000. The disease incidence was ranged 10-15% in the experimental fields. Transmission electron-microscopy of naturally infected tissues revealed the presence of pleomorphic bodies in the phloem region varied considerably in size, shape and electron opacity. Generally spherical and oval forms were recognized. The bodies showed the typical ultrastructural details of other known plant pathogenic phytoplasmas. They were bounded by a smooth trilaminar membrane and contained ribosome-like granules and DNA-like strands. The symptoms of the disease were temporarily suppressed when treated with the antibiotic tetracycline-HCl. This is the first report of phytoplasma disease of P. amarus from India.
Authors:S. Atta, A. Sattar, A. Ahmad, I. Ali, S.A. Nagra and T. Ahmad
Chicken and fish have been investigated for the detection of radiation treatment using thermoluminescence (TL) technique. The samples were irradiated by 60Co gamma-source at the absorbed doses of 1, 2, 3, 4 and 5 kGy. TL response of treated and untreated samples in the temperature range of 50–300 °C was measured using TL reader with a temperature profile of 10 °C/s. The results revealed that TL values increased with temperature and maximum signal were obtained at 195 °C, in each case. It was also observed that the TL intensities enhanced with the absorbed doses (1–5 kGy) and the increase was dependent on the absorbed dose. From this study it is concluded that the TL technique is a rapid, simple and promising method for identifying chicken and fish treated with gamma-irradiation.
Authors:A. Sattar, M.A. Cheema, A. Sher, T. Abbas, M. Ijaz, S. Ul-Allah, M. Butt, A. Qayyum and M. Hussain
The impact of trinexapac-ethyl (TE) on salinity subjected wheat plants was evaluated via pot based experiment. The treatments applied to wheat seedlings included (Ck) control (no NaCl nor TE spray), foliar spray of TE (1.95 ml L−1), only NaCl (50 mM) and NaCl+ TE (50 mM + 1.95 ml L−1). Foliar application of TE was done seven days after imposition of salinity. Growth parameters (root length, shoot length, fresh weight, and dry weight) and photosynthetic pigments content (chlorophyll a, b, a + b and a/b), water relation (water potential, osmotic potential, turgor potential and relative water contents) as well as catalase (CAT) activity exhibited marked reduction in comparison to control. In addition, an increment was noted in organic solutes content (proline, soluble protein and soluble sugar) and enzyme activity of superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) in stressed seedlings over control seedlings. The foliar applied TE mostly enhanced growth of salt stressed seedlings, accompanied by reinforcement in photosynthetic pigments, organic solutes, and enzyme activity (SOD, CAT, POD, and APX) in comparison to stressed seedlings. It is worthy to mention that, TE has potential to enhance salt tolerance of wheat seedlings. Thus, our findings suggest that seedling treated with TE is an effective strategy that can be used to enhance salt tolerance of wheat crop.
Authors:S. Abdul Sattar, B. Seetharami Reddy, V. Koteswara Rao, A. Pradeep, G. Naga Raju, K. Ramanarayana, P. Madhusudana Rao and S. Bhuloka Reddy
Trace elemental analysis was carried out in various parts of 10 anti-epileptic medicinal plants using PIXE technique. A 3 MeV
proton beam was used to excite the samples and spectra were recorded using a Si(Li) detector. Data analysis was done using
Gupix Software. The elements Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Br and Sr were identified and their concentrations estimated.
The presence of some of these trace elements is correlated with the anti-epileptic curative property of these plants.