EFFECT OF INOCULATION METHODS OF BIOZOTE-MAX (PLANT GROWTH PROMOTING RHIZOBACTERIA-PGPR) ON GROWTH AND YIELD OF RICE UNDER NATURALLY SALT-AFFECTED SOIL

A field experiment was carried out at the experimental farm of Soil Salinity Research Institute, Pindi Bhattian during 2016-17 to assess evaluate different Rhizobial inoculation methods on growth and yield of rice (Oryza sativa) cv. Basmati-385 under naturally salt-affected soil (pH= 8.12, ECe= 7.88 dS m-1and SAR=24.96). Seeds of rice were inoculated with Biozote–Max (Plant Growth Promoting Rhizobacteria-PGPR) produced in Soil Biology and Biotechnology Research Programme of Land Resources Research Institute, National Agricultural research Centre (NARC), Islamabad under PARC-Agrotech. Company (Pvt) Ltd. NARC, Islamabad in three ways i.e. rice seeds inoculated for direct seeding and nursery and dipping seedling roots in the solutions of these rhizobial strains comparable of control un-inoculated (control) by each inoculation method. The performances of Rhizobial strain Biozote–Max used as seed and seedling root dipping inoculation were superior to uninoculated control in all the parameters of the rice crop. Among the treatments, seed and seedling root dipping inoculation with Rhizobial strain Biozote–Max performed best in recording plant height, panicle length, number of tillers, 1000-grain weight and grain yield of rice crop. Maximum tillering was observed with all strains under different inoculation methods. Although, the strains performed better as compared to control, however, dipping of nursery roots produced significantly higher yield followed by seed inoculation for direct seeding. Overall, among all the inoculation methods seedling root dipping produced comparable paddy yield. The highest paddy yield (367 g m-2) was harvested with SBCC (M8) seed inoculation which was 13% more than that of un-inoculated (control)

Effectiveness of blended pedagogy for radiographic interpretation skills in operative dentistry - a comparison of test scores and student experiences at an undergraduate dental school in Pakistan

Abstract Background Utilizing Blended pedagogy (BP) in radiographic skills may prove to be an effective teaching strategy. However, studies on the use of BP in dentistry are quite limited in Pakistan, where teaching has mostly been via traditional Didactic Lectures (DL); and radiographic interpretation skills of undergraduate dental students are suboptimal. Therefore, this study aims to assess whether utilizing BP to teach radiographic interpretation skills is an effective teaching methodology in Pakistan. Methods This mixed-method study was conducted on final year dental students at Jinnah Medical and Dental College (JMDC). Two groups of students were utilized for this study, one taught by traditional DL and the other taught by BP for the same module. BP was conducted over six weeks. A post-module test was conducted in both groups. Additionally, the BP group completed a modified Community of Inquiry (CoI) survey tool and volunteered to discuss their experiences through a focused group discussion (FGD). Descriptive statistics were computed and independent sample t-test was used to analyse the difference between the scores of the two groups. Thematic analysis was performed for the qualitative data. Results The mean post-test scores were found to be significantly higher in the BP group (61.0 ± 10.2) compared to the DL group (44.4 ± 12.3) (p =  0.8). The mean scores for the modified CoI instrument were 4.0 ± 0.29 for the whole instrument; 4.25 ± 0.22 for Teaching Presence, 3.71 ± 0.23 for Social Presence and 3.97 ± 0.16 Cognitive Presence, with all three having a Cronbach’s alpha > 0.75. Thematic analysis revealed that BP students mutually agreed that BP method was beneficial with the appreciation of strong support from the facilitator. However, challenges like interrupted power supply and increased effort requirement from students were pointed out. Conclusion Students taught radiographic interpretation skills with BP in comparison to DL had higher test scores and expressed a positive experience demonstrated via a modified CoI survey and FGD. Considering the encouraging results found, dental schools should incorporate BP in their teaching methodology and follow-up studies are needed to further support the use of BP as an effective teaching methodology in Dentistry

Alleviation of Cadmium Stress by Silicon Supplementation in Peas by the Modulation of Morpho-Physio-Biochemical Variables and Health Risk Assessment

Agricultural soil quality degradation by potentially toxic elements, specifically cadmium (Cd), poses a significant threat to plant growth and the health of humans. However, the supplementation of various salts of silicon (Si) to mitigate the adverse effect of Cd on the productivity of peas (Pisum sativum L.) is less known. Therefore, the present investigation was designed to evaluate the exogenous application at various levels (0, 0.50, 1.00 and 1.50 mM) of silicate compounds (sodium and potassium silicates) on pea growth, gaseous exchange, antioxidant enzyme activities and the potential health risk of Cd stress (20 mg kg−1 of soil) using CdCl2. The findings of the study showed that Cd stress significantly reduced growth, the fresh and dry biomass of roots and shoots and chlorophyll content. In addition, electrolyte leakage, antioxidant enzymes and the content of Cd in plant tissues were enhanced in Cd-induced stressed plants. An application of Si enhanced the development of stressed plants by modulating the growth of fresh and dry biomass, improving the chlorophyll contents and decreasing leakage from the plasma membrane. Furthermore, Si addition performed a vital function in relieving the effects of Cd stress by stimulating antioxidant potential. Hence, a significant level of metal protection was achieved by 1.00 mM of potassium silicate application under the Cd levels related to stress conditions, pointing to the fact that the Si concentration required for plant growth under Cd stress surpassed that which was required for general growth, enzymatic antioxidants regulation and limiting toxic metal uptake in plant tissues under normal conditions. The findings of this research work provide a feasible approach to reduce Cd toxicity in peas and to manage the entry and accumulation of Cd in food crops

Risk Assessment of Potentially Toxic Metals and Metalloids in Soil, Water and Plant Continuum of Fragrant Rice

Globally, the demand for food is increasing day by day due to the rapid increase in the human population. Elevated levels of metals and metalloids in soils are biomagnified over time in crops cultivated in metal-contaminated soils, hence posing a risk of food chain contamination. The present investigation aimed to assess metal and metalloid concentrations in soil, water, and rice kernels which are widely cultivated in four districts of Punjab, Pakistan, and to determine the risk to human health. The results revealed that, of five rice varieties, super basmati was the most preferred by farmers due to its yield potential and consumer acceptance due to its taste and to its long kernel. A detailed analysis of metal and metalloid accumulation revealed that their mean concentration fluctuated in the soil, water, and rice samples in the study area. The decreasing trends of heavy metals and metalloids were observed to be Pb > Cu > As > Cr > Cd > Hg > Al in soil samples, Pb > Cr > Cu > Al > As > Hg > Cd in water samples, and Cu > Cr = Pb > Cd = Al > Hg > As in rice kernels. The bioconcentration factor for Cr was the highest in the Faisalabad area among all sampled sites. The pollution load index of As, Cd, and Hg registered the highest values, that were above the recommended safety threshold levels described by World Health Organization. The human health risk index was determined to be low at all sites except for As and Hg. These results point to potential health risks caused by the consumption of fragrant rice by humans. Regular monitoring is recommended to manage and control elevated concentrations and related health hazards as a result of the use of rice contaminated by the accumulation of metals and metalloids

Effect of ethyl methanesulfonate mediated mutation for enhancing morpho-physio-biochemical and yield contributing traits of fragrant rice

Background Chemical mutagenesis has been successfully used for increasing genetic diversity in crop plants. More than 800 novel mutant types of rice (Oryza sativa L.) have been developed through the successful application of numerous mutagenic agents. Among a wide variety of chemical mutagens, ethyl-methane-sulfonate (EMS) is the alkylating agent that is most commonly employed in crop plants because it frequently induces nucleotide substitutions as detected in numerous genomes. Methods In this study, seeds of the widely consumed Basmati rice variety (Super Basmati, Oryza sativa L.) were treated with EMS at concentrations of 0.25%, 0.50%, 0.75%, 1.0%, and 1.25% to broaden its narrow genetic base. Results Sensitivity to a chemical mutagen such as ethyl methanesulfonate (EMS) was determined in the M1 generation. Results in M1 generation revealed that as the levels of applied EMS increased, there was a significant reduction in the germination percent, root length, shoot length, plant height, productive tillers, panicle length, sterile spikelet, total spikelet, and fertility percent as compared to the control under field conditions. All the aforementioned parameters decreased but there was an increase in EMS mutagens in an approximately linear fashion. Furthermore, there was no germination at 1.25% of EMS treatment for seed germination. A 50% germination was recorded between 0.50% and 0.75% EMS treatments. After germination, the subsequent parameters, viz. root length and shoot length had LD50 between 05.0% and 0.75% EMS dose levels. Significant variation was noticed in the photosynthetic and water related attributes of fragrant rice. The linear increase in the enzymatic attributes was noticed by the EMS mediated treatments. After the establishment of the plants in the M1 generation in the field, it was observed that LD50 for fertility percentage was at EMS 1.0% level, for the rice variety. Conclusion Hence, it is concluded that for creating genetic variability in the rice variety (Super Basmati), EMS doses from 0.5% to 0.75% are the most efficient, and effective

Mass characterisation of elemental toxicants in popular cigarettes sale in Pakistan using ICP-OES

Environmental pollution and public health risks increase due to elevated metal levels in cigarettes throughout the globe especially in the developing countries. Herein, study is carried out to investigate the heavy metals and rare earth element contents in the popular cigarette brands (local and imported) in Pakistan. Twenty-six elements are measured in cigarette, tobacco, wrapping paper and filter (n = 168) sold in the Pakistan market in 14 brands of cigarettes using inductively coupled plasma-optical emission spectrometry (ICP-OES). The mean concentrations of Cr, V, Mo, Ni, Sn, As, Sb, Fe, Al, Mg, Ti and B (8.30, 0.22, 0.45, 1.85, 4.63, 1.32, 0.89, 378.01, 180.18, 2134.21, 6.53 & 22.20 μg/g), respectively, are slightly higher in local cigarette brands and the mean concentration of Co, Cd, Pb, Se, Sr, Mn, Cu, Zn, Ca, K, Na, Y, Zr and Ba (0.49, 0.69, 1.58, 1.47, 71.03, 68.23, 32.69, 32.33, 2906.82, 7601.73, 962.31, 0.10, 1.04 & 35.19 μg/g), respectively, are slightly higher in imported cigarette brands. The concentrations of Pb, Ni, Cd, Co, Fe and Zn in local tobacco cigarettes are approximately comparable to concentration levels of metals in imported tobacco cigarettes sold in other countries. While a strong positive correlation was observed in Cr, Sn, Mn, Ba, Ni, Co, As and Sr, while K, Mo, Ti, Ca and Mo were negatively associated with other elements. In addition, this study also provides an important information on the elemental levels such as alkali metals (Na & K), alkaline rare earth metals (Mg, Ca, Sr & Ba), transition metals (Ti, V, Mo, Y & Zr), post-transition metals (Sn), metalloids (B & As) and reactive non-metal (Se) for the very first time in Pakistan in different components of cigarettes. We believe that this study will be beneficial to the prevention of public health hazards and the reduction of human health risks through tobacco consumption.</p

Plant-Growth-Promoting Bioagents: A Sustainable Tool for Improving the Soil Health, Enhancing the Growth and Antioxidative Defense System of Tobacco

ABSTRACT: In the current era, the most crucial matter is to increase crop yields sustainably. Biological agents’ usage is an effective and environmentally friendly way to boost plant growth by activating the antioxidative defense system and improving soil health. The present investigation aimed at evaluating the bacterial (Bacillus subtilis, Bacillus amyloliquefaciens) and fungal (Trichoderma harzianum) bioagents in the sole and synergistic forms to improve tobacco (cultivar: Yunyan 87) growth by the mediation of antioxidant defense system and soil health. Bioagents were applied as root application at the rate of 100 ml suspension per plant after that same concentrations were applied 25 days of planting with four times taking 15 days intervals. Results revealed that soil application of these bioagents significantly enhanced growth, photosynthetic attributes, enzymatic antioxidants, and soil enzymatic activities. Combined application of bacterial and fungal bioagents improved the leaf area (121.50%), total chlorophyll contents (131.48%), polyphenol oxidase (PPO) (77.57%) and phenylalanine ammonia-lyase (PAL) activities (43.52%) as compared with control. Fungal bioagents marked better performance as compared to bacterial bioagents and control. The co-application of bioagents significantly enhanced the leaf quality attributes by decreasing the accumulation of proline, malondialdehyde content, and accumulation of chloride ions in tobacco leaves. The higher soil enzyme activities and essential nutrients were observed in the treatment of bacterial and fungal bioagents (application of Bacillus and Trichoderma spp.). In crux, the findings confirmed that the combined use of Bacillus and Trichoderma spp could contribute as a new cultivation practice for sustainable growth, productivity and quality of tobacco crop and can be recommended as safe and eco-friendly alternatives to preserve plant, soil, and human health for achieving the sustaibalility