Recently, Underwater Wireless Sensor Networks (UWSNs) have attracted much research attention from both academia and industry, in order to explore the vast underwater environment. However, designing network protocols is challenging in... more
Recently, Underwater Wireless Sensor Networks (UWSNs) have attracted much research attention from both academia and industry, in order to explore the vast underwater environment. However, designing network protocols is challenging in UWSNs since ...
... Communications: A Survey ... 5. COMPARITIVE DISCUSSION This section describes qualitative discussion and the pros & cons of the above mentioned protocols. ... Then the node with a high priority, based on some metrics, will... more
... Communications: A Survey ... 5. COMPARITIVE DISCUSSION This section describes qualitative discussion and the pros & cons of the above mentioned protocols. ... Then the node with a high priority, based on some metrics, will broadcast the packet. ...
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ABSTRACT Multi-hop communication in Underwater Acoustic Sensor Network (UASN) brings new challenges in reliable data transmission. Recent work shows that data collection from underwater sensor nodes using Autonomous Underwater Vehicle... more
ABSTRACT Multi-hop communication in Underwater Acoustic Sensor Network (UASN) brings new challenges in reliable data transmission. Recent work shows that data collection from underwater sensor nodes using Autonomous Underwater Vehicle (AUV) minimizes multi-hop data transmission, improving energy efficiency in UASN. However, due to continuous movements, AUV has limited communication time to collect data from sensor nodes in UASN. We therefore propose a novel underwater routing protocol, namely AEERP (AUV aided Energy Efficient Routing Protocol). In AEERP, an AUV collects data from gateway nodes. Among all the nodes, selected nodes play the role of gateway node for communication with AUV. Gateway nodes are selected based on RSSI values of the hello packet received from AUV. In addition, after consuming energy up to a certain threshold by a gateway node, another high energy node is selected as a gateway node. This adaptive selection of gateway node balances energy consumption increasing network lifetime. Mathematical analysis and NS-2 simulation show that AEERP performs better than Travel Salesperson Problem (TSP) in terms of energy cost and data delivery ratio.
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Desert flora shows a range of morphological and anatomical features under natural and simulated saline conditions. The morphological characteristics include smaller leaves, fewer stomata, increased succulence, thick cuticle and deposition... more
Desert flora shows a range of morphological and anatomical features under natural and simulated saline conditions. The morphological characteristics include smaller leaves, fewer stomata, increased succulence, thick cuticle and deposition of wax. The anatomical ones include salt secretory trichomes and glands at leaf level, thick and many layered epidermis and well developed water storing tissues in the cortex of stem, and reduced cortical area, widening of casparian band and enhanced development of root endodermis. Of these, the most important ones are salt-secretary trichomes and salt glands. With few structural differences, they are similar functionally and are associated with the secretion of ions. In this review an attempt has been made to present a detailed account of salt glands and trichomes in relations to their functions, together with the pathways and mechanisms of ion-secretion, in the halophytes endemic to desert environments.
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Water shortage is the main constraint limiting crop productivity across the globe especially when it occurs at reproductive and grain filling stages. This study was conducted to monitor the mechanisms of drought resistance, during... more
Water shortage is the main constraint limiting crop productivity across the globe especially when it occurs at reproductive and grain filling stages. This study was conducted to monitor the mechanisms of drought resistance, during reproductive stages (booting, heading anthesis and post-anthesis stages) by monitoring the stay green character, water use efficiency, grain filling rate, grain filling duration, grain yield and harvest index. Seeds of wheat cultivars C-591, Mairaj-2008 were sown in 10 kg soil filled pots on November 25, 2011. The drought stress was applied at the respective reproductive stage, which continued till maturity. Controlled plants were well-watered throughout the crop ontogeny. Pots were maintained at 70% water holding capacity (WHC; well watered) till booting stage and then managed drought stress was induced as per treatment maintaining 35% WHC (drought stress). Drought stress at all the stages significantly influenced the crop performance in all the tested cu...
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This study was conducted to determine the growth, mineral nutrient responses of selected heat-resistant (Sadaf) and heat susceptible (Agatti-2002) varieties of maize to simulated glasshouse (GH) conditions during Spring and Autumn seasons... more
This study was conducted to determine the growth, mineral nutrient responses of selected heat-resistant (Sadaf) and heat susceptible (Agatti-2002) varieties of maize to simulated glasshouse (GH) conditions during Spring and Autumn seasons at seedling, silking and grain filling stages. Fifteen day old plants were shifted to plexiglass-fitted canopies to create GH conditions. Mean radiation intensities inside and outside the canopy during the Spring and Autumn seasons were 1085 μmol m-2 s-1 and 976 μmol m-2 s-1, respectively. Simulated GH conditions increased the canopy temperature 4-7C in the Spring season and 3-5 C in the Autumn-season, but increased relative humidity by 2-3% in the Spring season and 5-9% in the Autumn-season. Such an increase in temperature, referred to as heat stress, was more damaging to the absorption of potassium (K+), calcium (Ca2+) and nitrate (NO31-) during Spring season. Heat stress hampered the shoot K+, Ca2+ and NO3- in both varieties, especially in Spri...
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Weeds are stringent biological constraint to direct seeded rice (DSR) growth and yield. Cultural practices alter patterns of crop growth and can modify dynamics of weed-crop competition, and hence need to be investigated as a tool for... more
Weeds are stringent biological constraint to direct seeded rice (DSR) growth and yield. Cultural practices alter patterns of crop growth and can modify dynamics of weed-crop competition, and hence need to be investigated as a tool for sustainable weed management in DSR. Field studies were carried out during summer 2010 and 2011 to explore the growth response of DSR to different tillage systems, sowing times and durations of weed competition. A commonly grown rice cultivar, Super Basmati was sown on 15th June and 7th July under zero (ZT) and conventional tillage (CT) and was subjected to different durations of weed competition (10, 20, 30, 40, 50 DAS and season long competition). Weed free plots were maintained under each tillage system and sowing time for comparison. Crop growth rate and dry matter accumulation by DSR varied significantly under tillage systems, sowing times, duration of weed competitions, and their interactive effect. During 2010, season long weed free plots sown un...
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Salinity and high temperature are amongst the highly damaging factors for crop production. The exogenous application of thiourea, due to its distinct properties, can potentially reduce these adverse effects. In this research, we... more
Salinity and high temperature are amongst the highly damaging factors for crop production. The exogenous application of thiourea, due to its distinct properties, can potentially reduce these adverse effects. In this research, we investigated the possible role of foliar spray of thiourea in improving the salinity tolerance threshold (EC e) and high temperature tolerance of five wheat varieties at seedling, pre-anthesis and grain filling stages of growth. Data were recorded for changes in length and dry weight of shoot and root and leaf area at seedling and pre-anthesis stages, while yield and yield components were recorded at maturity. Results revealed great varietal differences in the salinity and high temperature tolerance at all growth stages. Foliar applied thiourea improved EC e (6-11%) and high temperature tolerance (4-10%) in these varieties at different stages. Correlations of growth and yield attributes substantiated the effectiveness of foliar spray of thiourea in promoting...
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Upcoming increase in global warming is potential threat to crop production, which necessitates determining responses of crops to cope with this ever-increasing adversary. This study focused on the responses of two differentially heat... more
Upcoming increase in global warming is potential threat to crop production, which necessitates determining responses of crops to cope with this ever-increasing adversary. This study focused on the responses of two differentially heat tolerant maize (Zea mays L.) varieties Sadaf (heat tolerant) and Agatti-2002 (heat sensitive) to glasshouse condition at three growth stages across spring and autumn seasons (by keeping the plants inside the glass canopies). Results revealed that growth and yield responses of maize varieties were quite differential across the seasons and treatments, which was evident from the interactions of varieties and treatment present in one season and disappeared in the other. Among the growth attributes, silking and grainfilling stages during spring season were more sensitive to glasshouse effect as most the interactions of varieties and treatments were evident for various growth attributes. Although glasshouse condition diminished all the studies growth and yiel...
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Delay in wheat sowing in rice-wheat cropping system is perhaps the one of the major factors responsible for low crop yield. This reduction in yield is due to the sub-optimal temperature during the germination, stand establishment and... more
Delay in wheat sowing in rice-wheat cropping system is perhaps the one of the major factors responsible for low crop yield. This reduction in yield is due to the sub-optimal temperature during the germination, stand establishment and supra-optimal during the reproductive growth. In this study, performance of wheat cultivars (viz. Lasani-2008, Faisalabad-2008, Shafaq-2006, Sahar-2006 & Inqlab-91) sown on November 10 and December 10 was evaluated. Crop emergence was impaired when sowing was delayed owing to low temperature prevailing during stand establishment, which resulted in poor stand establishment and reduced the number of productive tillers and ultimately the final yield. With delay in planting, high temperature (32-39ºC) at reproductive stage during March and April reduced the patterns of dry matter accumulation as was evident from decrease yield related traits and the final yield. Nonetheless an increase in grain protein contents was observed in late sown crop. To conclude cu...
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To cite this paper: Ahmad, I., S.M.A. Basra and A. Wahid, 2014. Exogenous application of ascorbic acid, salicylic acid and hydrogen peroxide improves the productivity of hybrid maize under at low temperature stress. Int. Abstract Maize... more
To cite this paper: Ahmad, I., S.M.A. Basra and A. Wahid, 2014. Exogenous application of ascorbic acid, salicylic acid and hydrogen peroxide improves the productivity of hybrid maize under at low temperature stress. Int. Abstract Maize being subtropical crop is sensitive to low temperature at early growth stages. Exogenous application of ascorbic acid (AsA), salicylic acid (SA) and hydrogen peroxide (H 2 O 2) can improve the seedling growth of maize at early growth stages. In these studies, the effect of exogenous application of AsA, SA and H 2 O 2 to improve the maize performance at sub-optimum temperatures was investigated in pots and field experiments.. In pot experiment, AsA, SA and H 2 O 2 were foliage applied at 20 or 40 mg L-1 at 3rd leaf stage. In field experiment, these three substances were applied as seed priming or as foliar spray. In pot experiment, foliar application of AsA, SA and H 2 O 2 at each concentration improved seedling growth, leaf relative water, chlorophyll...
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Heavy metals greatly alter plant morphology and architecture, however detailed mechanisms of such changes are not fully explored. Two experiments were conducted to investigate the influence of cadmium (CdCl2 .2.5H2 O) on some germination,... more
Heavy metals greatly alter plant morphology and architecture, however detailed mechanisms of such changes are not fully explored. Two experiments were conducted to investigate the influence of cadmium (CdCl2 .2.5H2 O) on some germination, morphological, biochemical and histological characteristics of developing embryonic tissue of maize. In the first experiment, maize seeds were germinated in increased levels of CdCl2 (200 to 2000 μM) in sand and measurements were taken for changes in germination and seedling development attributes. Based on these parameters, 1000 μmol/L CdCl2 level was chosen for detailed biochemical and histological measurements. In the second experiment, the seeds were germinated in petri-dishes and supplied with 0 (control) and 1000 μmol/L CdCl2 level (Cd-treated). Radicle, plumule, coleoptile and coleorhiza were measured for biochemical and histological changes. Highest amount of Cd was noted in coleorhiza and radicle. Free proline, soluble sugars, anthocyamins...
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ABSTRACT This study investigated the impact of allelopathic crops residue amendments and a nitrification inhibitor DMPP (3, 4-dimethylpyrazole Phosphate) on germination, growth, yield and nitrogen (N) use of wheat. In the first study,... more
ABSTRACT This study investigated the impact of allelopathic crops residue amendments and a nitrification inhibitor DMPP (3, 4-dimethylpyrazole Phosphate) on germination, growth, yield and nitrogen (N) use of wheat. In the first study, wheat cultivars [Lasani 2008 (LS-08) and Faisalabad 2008 (FSD-08)] were grown in soil filled pots (18 kg soil) amended with sorghum and sunflower residues (0, 8 and 12 Mg ha(-1)) in presence and absence of nitrogen fertilizer sources [urea and ammonium sulphate (N at 110 kg ha(-1))]. Plants were raised up to maturity; sorghum residue amendments improved the performance of both wheat cultivars; however sunflower residues initially inhibited wheat germination and stand establishment but at later growth stages, the inhibitory effects were diminished. Both N sources improved grain yield of wheat cultivars with greater by ammonium sulphate in LS-08. Sorghum residue at 12 Mg ha(-1) in addition with ammonium sulphate had significant influence on grain yield of cv. LS-08 than other treatments. In second experiment, cv. LS-08 was grown in soil filled pots amended with sorghum and sunflower residue (16 and 32 Mg ha(-1)) in presence or absence of DMPP (0.36 mu g g(-1)) in greenhouse. DMPP in combination with N in the absence of crop residues improved dry matter production and reduced the C:N ratio; however any residue addition at any rate immobilized N and decreased the dry matter accumulation. In crux, residue amendments in combination with inorganic fertilizers could improve wheat grain yield, while combined use of DMMP and N can improve plant N availability and dry biomass. (C) 2015 Friends Science Publishers
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... Toxic Cadmium Levels in Plants Molecular and cytological processes Physiological and biochemical processes Impaired growth, development and reduced yield ... Disturbance inAnatomical and developmental events ... A s abo v e T obacco (... more
... Toxic Cadmium Levels in Plants Molecular and cytological processes Physiological and biochemical processes Impaired growth, development and reduced yield ... Disturbance inAnatomical and developmental events ... A s abo v e T obacco ( Nicotiana tabacum ) L eaf As abo ...
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Cadmium (Cd) is a highly toxic soil contaminant affecting crops growth particularly at early stages. Objective of this study was to find varietal differences in mungbean (Vigna radiata (L.) Wilczek) for growth and seedling survival under... more
Cadmium (Cd) is a highly toxic soil contaminant affecting crops growth particularly at early stages. Objective of this study was to find varietal differences in mungbean (Vigna radiata (L.) Wilczek) for growth and seedling survival under the increased Cd-levels. With substantial varietal difference, applied Cd enhanced the seedling mortality more notably at higher levels. Leaves of all the varieties showed
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Research Interests: Genetics, Agronomy, Plant Biology, Water Availability, Food Security, and 17 moreWater Demand, Water use efficiency, Profitability, Water Saving, Methane, Soil organic matter, Greenhouse Gas Emissions, Soil sciences, Water Conservation, Drought tolerance, Integrated Approach, Nitrous Oxide, System of Rice Intensification, Production System, Water Productivity, Nutrient dynamics, and Integrated Natural Resource Management
Research Interests: Sustainable agriculture, Sustainable, Drought Stress, Environmental Sciences, Water use efficiency, and 24 moreWater balance, Plant growth, Marker assisted selection, Potassium, Oscillations, Transcription Factor, Enzyme, Drought tolerance, Water Loss, Auxin, Amino Acid Profile, Plant production, Management Strategy, Root System, Plant Water Relations, Water Deficit, Crop Yield, Salicylic Acid, Leaf Size, Osmotic Adjustment, Drought Resistance, Low molecular weight, Organic Acid, and Adenosine Triphosphate
Influence of NaCl salinity was studied on four mungbean (Vigna radiata (L.) Wilczek) genotypes to decipher the changes in visual signs of salt damage, growth and seed yield, mineral nutrient and pigment composition at early vegetative... more
Influence of NaCl salinity was studied on four mungbean (Vigna radiata (L.) Wilczek) genotypes to decipher the changes in visual signs of salt damage, growth and seed yield, mineral nutrient and pigment composition at early vegetative (EVS), late vegetative (LVS) and reproductive (RS) stages of growth. Although the genotypes exhibited sensitivity to salinity at all stages, salt tolerance (mM50; NaCl
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Sugarcane (Saccharum officinarum L.) an important sugar crop, shows high sensitivity to salinity at vari- ous growth stages. This study was conducted to determine the comparative response of a salt-tolerant (CP-4333) and a salt-sensitive... more
Sugarcane (Saccharum officinarum L.) an important sugar crop, shows high sensitivity to salinity at vari- ous growth stages. This study was conducted to determine the comparative response of a salt-tolerant (CP-4333) and a salt-sensitive (CP-71-3002) sugarcane clone to the toxic or osmotic effects of sodium chloride at two growth stages. Clones indicated significant differences in terms of reductions in dry
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Studies on the functional roles of dehydrins (DHNs) in heat tolerance of plants are scarce. This study was conducted to immunohistolocalize DHNs in leaves of heat-tolerant (CP-4333) and heat-sensitive (HSF-240) sugarcane (Saccharum... more
Studies on the functional roles of dehydrins (DHNs) in heat tolerance of plants are scarce. This study was conducted to immunohistolocalize DHNs in leaves of heat-tolerant (CP-4333) and heat-sensitive (HSF-240) sugarcane (Saccharum officinarum L.) clones at three phenological stages in order to elucidate their putative roles under heat stress. CP-4333 indicated greater amounts of heat-stable proteins than HSF-240 under heat stress. Western blotting revealed the expression of three DHNs in CP-4333 (13- and 15-kDa peptides at 48 h and an additional 18-kDa band at 72 h) and two (13 and 15 kDa at 48 h) in HSF-240 at formative stage; two DHNs in CP-4333 (20 and 25 kDa) and one in HSF-240 (20 kDa) at grand growth stage, while two DHNs in CP-4333 (20 and 22 kDa) and one in HSF-240 (20 kDa) at maturity stage. Tissue-specific immunohistolocalization showed that DHNs were expressed in stele particularly the phloem and the cells intervening bundle sheath and vascular bundles. Furthermore, DHNs were also found scattered along the epidermal and parenchymatous cells. Recovery of sugarcane from heat stress manifested a gradual disappearance of DHNs in both the clones, being quicker in sensitive clone (HSF-240). Results suggested specific implications for DHNs synthesis. Their synthesis in epidermis appears to protect the mesophyll tissues from heat injury. When associated to vascular tissue, they tend to ensure the normal photoassimilate loading into the sieve element-companion cell complex. DHNs diminution during recovery suggested that their expression was transitory. However, prolonged retention of DHNs by tolerant clone appears to be an adaptive advantage of sugarcane to withstand heat stress.
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Heat stress adversely affects plant growth and development, while glycinebetaine (GB) plays a protective role under stressful conditions. The objective of this study was to assess the optimum level of GB for use as a presowing seed... more
Heat stress adversely affects plant growth and development, while glycinebetaine (GB) plays a protective role under stressful conditions. The objective of this study was to assess the optimum level of GB for use as a presowing seed treatment and the subsequent effect on the heat tolerance of barley (Hordeum vulgare L. cv. Haider-93) seedlings. Among a range of GB levels,
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ABSTRACT Boron (B) is amongst the important micronutrients required for rice from start till physiological maturity. This study was conducted to explore the role of boron application in seedling emergence, leaf appearance and elongation,... more
ABSTRACT Boron (B) is amongst the important micronutrients required for rice from start till physiological maturity. This study was conducted to explore the role of boron application in seedling emergence, leaf appearance and elongation, chlorophyll content, water relations and yield related traits of fine rice. Boron was applied as seed priming. For priming seeds of fine rice cultivars Super Basmati and Shaheen Basmati were soaked in 0.001 and 0.01 % aerated B solutions (w/v); while untreated dry seeds and water soaked (hydropriming) seeds were taken as control. Substantial improvement in seedling emergence was noted by seed priming in 0.001 and 0.01 % solutions. Rate of leaf emergence and elongation and tiller appearance were also improved in seedlings raised from seeds primed in 0.001 % B solution in the tested cultivars. Likewise, leaf chlorophyll contents were significantly improved by B especially with 0.001 % concentration; as was the case for water relations of rice cultivars. At final harvest, all yield contributing parameters were improved by B priming. Increase in yield was due to decrease in panicle sterility by B treatments. A linear increase in leaf and grain B contents was observed with increase in concentration of B priming solution. Overall, B application at very low rate substantially improved seedling emergence, leaf appearance and elongation, tillering, chlorophyll, water relations and yield related traits resulting in better yield and grain B contents. In this regard, seed priming offers an effective and pragmatic way of B application.