Brassinosteroid Enhances Cold Stress Tolerance of Washington Navel Orange (Citrus sinensis L.) Fruit by Regulating Antioxidant Enzymes During Storage

The effect of brassinosteroid (BR) on chilling injury of Washington Navel orange (Citrus sinensis L.) fruit was investigated. BR at the concentrations of 0.75 and 1.5 ppm effectively reduced chilling injury of Washington Navel orange fruit during five months storage at 3°C, and BR at 1.5 ppm showed the best effect. BR treatment also reduced the lipid peroxidaion and peroxide hydrogen content of peel and pulp during storage. Results of physiological response in orange fruit showed that BR induced the activity of antioxidant enzymes including catalase and peroxidase. These results indicate that the elicitation of an antioxidant response in orange fruit by BR may be associated with chilling injury alleviation. Moreover, BR maintained the orange quality by decrease of lipid peroxidation and peroxide hydrogen content. The present study is the first evidence that BR enhances orange fruit tolerance to cold stress and therefore fruit quality

TDR Approach Employment in Dealing with Metropolitan Area’s Sprawl; Isfahan Metropolitan Area, District 9

Transfer of Development Rights (TDR), as a market-led mechanism, attempts to managing the urban growth and facing urban sprawl, with reference to the valuable lands, through balancing between public and private interests. This approach has been raised following the master plans inefficiencies in protecting valuable natural lands and zones. Due to the master plans failure in facing urban sprawl and managing the cities’ growth in a smart way in Iran this concept has been put forward in academics and professional arenas in recent decades. But, due to the lack of institutional context and necessary soft perquisites, it has not been realized and moved beyond theoretical fields. Similar to most of the Iran’s’ city districts, district no 9 in Isfahan Metropolitan Area- which is famous because of its orchards and landscaped lush and productive agriculture-has been exposed to the commercialization and mass unplanned constructions. As a result its valuable environmental assets, which act as a respiratory lung of the city, exposed to destruction. This is while many lands are abandoned within the city. These issues raised the necessity of TDR approaches employment for the aim of growth management. In this regard, the main question is that what the main institutional perquisites are and by which means a reliable institutional context would be provided for realization of this mechanism in the selected district as the research case study. The following research, with the intention of answering this question, is up to identify those theoretical perquisites through literature reviews methods such as meta-synthesis and field research methods. Afterwards, due to the extracted conceptual frameworks, 4 main institutions’ vision about TDR’s soft perquisites, including citizens, developer, landowners and urban experts, would be analyzed by means of statistical methods such as Friedman and T tests, Multivariate regressions and SWOT analysis. Based on the results, this approach employment requires long term smart plans to achieve successful outputs, since variety of institutional barriers such as low regional consciousness, unwillingness to participate and not providing the necessary legal grounds

Microleakage of CEM cement in two different media

INTRODUCTION: Sealing ability of root-end filling materials is of great importance. It can be investigated by measuring microleakage. The purpose of this in vitro study was to evaluate microleakage of calcium enriched mixture (CEM) cement in two different media including phosphate buffer solution (PBS) and distilled water. MATERIALS AND METHODS: Twenty single-rooted human teeth were selected. All teeth were root-end filled with CEM cement. Samples were divided into two groups of 10 each and were placed in PBS or distilled water. The microleakage was measured after 12 and 24 h, 14 and 30 days with Fluid Filtration device. Data were statistically analyzed by repeated measures test. RESULTS: Sealing ability of CEM cement was significantly superior in PBS compared to distilled water (P<0.05). This study also showed that time had no significant effect on the sealing ability of CEM cement. CONCLUSION: Media can significantly affect the microleakage of CEM cement. PBS can provide more phosphorous ions for hydroxyapatite formation of CEM cement; therefore, CEM cement can seal more effectively with PBS

Effect of Nitric Oxide Application on Reduction of Undesirable Effects of Chilling on Washington Navel orange (Citrus sinensis L.) Fruit During Storage

Introduction: Chilling injury (CI) is the primary postharvest problem of orange (Citrus sinensis L.) and many other horticultural crops during storage. Washington Navel orange fruits are susceptible to CI during storage below 5°C, and the main CI symptoms are surface pitting, browning, discoloration and decay. Several promising methods have been developed to alleviate CI symptoms of orange fruit. These include postharvest physical treatments with UV-C, modified atmosphere packaging, temperature conditioning, and chemical treatments with plant growth regulators. Oxidative stress from excessive reactive oxygen species (ROS) has been associated with appearance of chilling damage in fruits. The oxidation of ROS is due to their reaction with numerous cell components coursing a cascade of oxidative reactions and consequent inactivation of enzymes, lipid peroxidation, protein degradation, and DNA damage. Aerobic organisms have evolved well-developed defense systems to establish a fine-tuned balance between ROS production and removal plants are protected against ROS effects by a complex antioxidant system. This involved both lipid soluble antioxidant (α- tocopherol and carotenoids) and water soluble reductants (glutathion and ascorbate) and enzymes, such as catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD) and peroxidase (POD). Previous studies have shown that there is a positive relationship between the antioxidant enzymes activity and the chilling tolerance in harvested fruits. Nitric oxide (NO) is an important signaling molecule involved in many plant physiological processes. It has also been indicated that NO protects plant cells against oxidative stress by reducing ROS accumulation. When exogenously applied, NO has been shown to result in an improved chilling tolerance and reduced incidence of chilling injury in several fruits. The objectives of this study were to evaluate the effects of NO on chilling injury, lipid peroxidation content, peroxide hydrogen content, and the induction of antioxidant enzymes in Washington Navel orange (Citrus sinensis L.) fruit during storage at 5±1°C. Materials and Methods: Washington Navel orange (Citrus sinensis L.) fruits were harvested at commercial maturity from a commercial orchard in Kerman, Iran, and transported to the laboratory on the same day. Orange fruits were treated with 0.25 and 0.5 mM nitric oxide for 5 min and then stored at 5±1°C and relative humidity of 85-90 % for 5 months. No nitric oxide use was considered as control. The experiment was arranged in completely randomized design (CRD) with three replicates. Characteristics such as chilling injury, total soluble solids, titratable acidity, pH, ascorbic acid, and activity of antioxidant enzymes (peroxidase and catalase) were evaluated in the present experiment. Results and Discussion: The results showed that use of nitric oxide in fruits reduced significantly chilling injury, ion leakage, lipid peroxidation and hydrogen peroxide compared to control, though it increased activity of antioxidant enzymes. According to these results, unlike organic acids which decreased in treated and non-treated fruits, total soluble solids, ascorbic acid and pH of the fruits increased during storage, however, nitric oxide treatment reduced the rate of changes, be either reducing or increasing, in the mentioned parameters compared to control. So, fruits treated with 0.5 mMol nitric oxide showed the highest effect on the reduction of chilling injury. In the present study, the results indicated that NO significantly reduced CI of orange fruits during storage at 5±1 °C. NO has been applied to reduce the development of chilling injury symptoms in a number of horticultural crops. Thus NO has the potential of application in postharvest treatment by alleviating chilling injury and maintaining quality, and the aim of this study was to determine how NO alleviates the anti-oxidative systems, probably one of the mechanisms of improved chilling tolerance, of orange fruit during chilling stress. This indicates that the chilling tolerance of orange fruit was also enhanced by postharvest treatment with NO. Lipid peroxidation and protective enzyme systems are often evaluated in studies of plant mechanisms under various stresses. Low temperature disrupts the balance of active oxygen species metabolism, leading to their accumulation and destruction of scavenging enzymes such as catalase and peroxidase. In the present study, exogenous per-treatment with nitric oxide at 0.25 and 0.5 mM significantly decreased the lipid peroxidation content and electrolyte leakage of cold stored orange fruit compared to untreated fruits. The level of H2O2 was maintained by NO treatment, which led to an increase in chilling tolerance. It has been reported that the improvement of chilling tolerance in harvested horticultural crops is related to the enhancement in activates of antioxidant enzyme. Researchers found that chilling-tolerant mandarins have a higher antioxidant enzyme activity than the chilling-sensitive ones. A number of postharvest treatments that induce chilling tolerance and alleviate chilling injury also enhanced antioxidant enzyme activity. However, to the best of our knowledge, this is the first paper reporting the beneficial effects of NO on CI of postharvest orange fruits. In this study, there was a continuous increase in peel and pulp lipid peroxidation content in all fruits, but the application of NO significantly delayed the increase of lipid peroxidation. Moreover, the change in membrane permeability (revealed by H2O2 content) showed trends similar to lipid peroxidation content; in other words, peel and pulp H2O2 content increased with storage duration, but NO markedly delayed the increase. NO has been considered to be involved in a network of interacting signal transduction pathways, which regulate defense responses to abiotic stress. The detoxification of ROS is dependent on antioxidant enzymes such as CAT and POD. The increase in these enzymes’ activity contributes to the adaptation of plants to cold stress and ameliorates oxidative damage such as lipid peroxidation (lipid peroxidation increase as indicator) and H2O2 content. Conclusion: In conclusion, application of NO reduced CI of oranges stored at 5±1°C and maintained oranges quality as well. The chilling injury, lipid peroxidation, and peroxide hydrogen were significantly reduced by NO treatment especially at 0.5 mM. Induced cold resistance by NO treatment may be due to the stimulation of antioxidant enzymes, and protection against membrane oxidative damage, decreased lipid peroxidation and H2O2 content in orange fruits. These results may have implications for the use of NO in managing postharvest CI of other subtropical fruits stored at low temperatures

Evaluation of integrated management of soil fertilizers and summer irrigation on agronomic criteria and flower and stigma yield of saffron

In order to evaluate the effects of organic, chemical and biological fertilizers and summer irrigation on growth characteristics, corm yield, flower yield and stigma yield of saffron, field experiment was conducted as factorial based on a randomized complete block design with three replications at Agricultural Research station, Faculty of Agriculture, Ferdowsi University of Mashhad during three growing season of 2013-2014, 2014-2015 and 2015-2016. The first factor included of animal cow manure (a1), chemical fertilizer (such as Nitrogen, P and K) (a2), Thiobacillus (a3), sulfur (a4), a3+a4 and control (a5) and the second factor was summer irrigation in three levels such as conventional irrigation (A: without summer irrigation), A+ once summer irrigation (23 July), A+ twice summer irrigation (22 June+23 July). Studied characteristics were number and fresh weight of flower, dry weight of stigma, corm diameter, corm weight in four groups (16 g), corms with contractile roots, number of flowering buds per corm, leaf length, dry weight of leaf and dry weight of tunic of saffron. The results in the third of experiment revealed that the interaction effect between fertilizers and summer irrigation were significant (P≤0.01) on all studied traits of saffron except stigma dry weight, corms with weight more than 16 g and dry weight of daughter corms. The highest flower number (282.7 per m2), flower fresh weight (103.2 g/m2), stigma dry weight (1.73 g/m2), leaf dry weight (13.33 g/m2), buds dry weight (4.61 g/m2), flowering buds number per corm (2.627), corm percentage with cractile roots (58.41%), corm diameter (2.97 cm) and corms in different weight were obtained in animal manure and A+once summer irrigation. About simple effects, the highest stigma dry weight and dry weight of daughter corms were observed in animal manure and the highest amount of this traits were obtained in treatment A+once summer irrigation. It seems that summer irrigation increased the flower and stigma yield of saffron due to decreasing soil temperature

Mapping Spatial Distribution of Forest Fire using MCDM and GIS (Case Study: Three Forest Zones in Guilan Province)

Fire in forests and rangelands degrades vast part of natural resources. Although predicting the exact time and location of fire occurrence is a difficult task due to various parameters affecting wildfires, but application of Geographical Information System enables us to identify and control areas with high fire potential. The purpose of this study was to achieve a fire hazard map, developed by integrating several data layers such as topography, climate, vegetation cover and socio- economical factors. Some forest sites of Guilan province of I.R. Iran were selected for the study project due to their high cover density and their frequent fire occurrence history. Because the fire influencing parameters do not affect fie occurrence and distribution equally, a multi criteria method was used to grade them. The Fuzzy Analytical Hierarchy Process (FAHP) was used to consider uncertainties and to weight the criteria within 0 and 1 values. After calculating the Fuzzy weights and allocating them to the raster maps of the influencing parameters, finally the weighted informational layers were integrated and overlaid in the GIS. To assess accuracy of the applied method, the final fire hazard map was compared to further layer consisting of areas with high fire frequency during the last five years. Results showed that 66% of the hazard fire points were completely overlaid on sites with high and vey high fire risk, which reveals the capability of the study method in predicting forest fire potential. Furthermore, short distance between forests, roads and residential areas, identified as the main factors affecting fire occurrence and forest degradation more than the topographical parameters

Effect of Aloysia citrodora essential oil on biochemicals, antioxidant characteristics, and shelf life of strawberry fruit during storage

Strawberry fruits are highly susceptible to cold burning, resulting in low storage periods at low temperatures. Plant extracts or essential oils (EOs) can potentially be used as preservatives in fruits throughout the refrigerated period. In the present study, the biochemicals, antioxidant characteristics, and shelf life of treated strawberries with Aloysia citrodora essential oil (ACEOs) were evaluated during keeping time. The treatments were produced as follows: T1, control; T2, 250 ppm ACEOs; T3, 500 ppm ACEOs; and T4, 750 ppm ACEOs. Total soluble solids (TSS), weight loss, titratable acidity (TA), antioxidant activity (DPPH assay), total phenolic (TPC), flavonoid and anthocyanin contents (TFC), and enzymes activity (peroxidase and ascorbate peroxidase) were evaluated during the refrigerated period (5 °C with relative humidity of 85–90% for 20 days). The results revealed that weight loss and TA were reduced in all treatments during storage, being that the rates were lower in samples treated with ACEOs. TPC, TFC, TSS, antioxidant, and enzymes activity were higher in treated fruits than control