A low-level jet in eastern Iran: a possible factor in dust events in the region
Sharon
Nicholson
Earth, Ocean and Atmospheric Science Department, Florida State University, Tallahassee, FL 32306, USA
author
text
article
2015
eng
One of the world's major mineral dust source regions lies along the border between Iran and Afghanistan. In this studyit is hypothesized that a low-level jet may play in role in generating the intensity of this source region. The presence of alow-level jet east of the Seistan mountains is documented here for the first time. The jet exists mainly from May toSeptember and has a core at 850 mb. Maximum speeds are at 18 UTC and 0 UTC and occur in July-August. In the meanthe core speed attains 20 ms-1 in those months. The jet attains a maximum at night, a minimum during the day. However, the vertical motions associated with it do not fluctuate greatly over the course of the day. The development of the jet during a dust outbreak in 2002 is also described. It arises a day or so before the outbreak and disappears as the outbreak ends.
Desert
University of Tehran
2008-0875
20
v.
2
no.
2015
91
99
https://jdesert.ut.ac.ir/article_56473_029d11199a321e18944cdfa92a6789eb.pdf
dx.doi.org/10.22059/jdesert.2015.56473
Climate change scenarios generated by using GCM outputs and statistical downscaling in an arid region
Zhaofei
Liu
Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 100101, Beijing, China
author
Zongxue
Xu
Key Laboratory of Water and Sediment Sciences, Ministry of Education; College of Water Sciences, Beijing Normal University, Beijing 100875, China
author
text
article
2015
eng
Two statistical downscaling models, the non-homogeneous hidden Markov model (NHMM) and the Statistical Down–Scaling Model (SDSM) were used to generate future scenarios of both mean and extremes in the Tarim River basin,which were based on nine combined scenarios including three general circulation models (GCMs) (CSIRO30, ECHAM5,and GFDL21) predictor sets and three special report on emission scenarios (SRES) (SRES A1B, SRES A2, and SRESB1). Local climate change scenarios generated from statistical downscaling models was also compared with thatprojected by raw GCMs outputs. The results showed that the magnitude of changes for annual precipitation projected byraw GCMs outputs was greater than that generated by using statistical downscaling model. The difference betweenchanges of annual maximum air temperature projected by statistical downscaling model and raw GCMs outputs was notas significant as that for annual precipitation. In total, the magnitude of these increasing trends projected by bothstatistical downscaling models and raw GCMs outputs was the greatest under SRES A2 scenario and the smallest underB1 scenario, with A1B scenario in–between. Generally, the magnitude of these increasing trends in the period of 2081 to2100 was greater than that in the period of 2046 to 2065. The magnitude of standard deviation changes for dailyprecipitation projected by raw GCMs outputs was greater than that generated by statistical downscaling model undermost of combined scenarios in both periods.
Desert
University of Tehran
2008-0875
20
v.
2
no.
2015
101
115
https://jdesert.ut.ac.ir/article_56474_b1a074a31a0097b620560bf9392f12d0.pdf
dx.doi.org/10.22059/jdesert.2015.56474
First observations of the aquatic invertebrate fauna in ephemeral Atacama River (22° S, Antofagasta Region, Chile)
Patricio
De los Rios Escalante
Universidad Catolica de Temuco
Facultad de Recursos Naturales
Escuela de Ciencias Ambientales
Casilla 15-D
Temuco
CHILE
email: prios@uct.cl
author
Konrad
Górski
Departamento de Ecología, Facultal de Ciencias, Universidad de Católica de la Santísima Concepción, Concepción, Chile
author
Patricio
Acevedo
Universidad de la Frontera
Temuco
CHILE
author
Manuel
Castro
Universidad de la Frontera
Temuco
CHILE
author
text
article
2015
eng
The invertebrate communities of the northern Chilean rivers are characterised by their marked endemism andspecificity of their community structure in different basins. The river systems located in the Atacama Desert are endorheicand are affected by the rainy period of January-February commonly known as the “Bolivian winter“. The present study isthe first report on the observations of arthropods in the ephemeral Atacama River during a period of the “Bolivian winter“.The Atacama River is characterised by species with poor invertebrate assemblage dominated by diapausing crustaceans(cladocera, copepod, ostracoda) and dispersing aquatic insects (ephemeroptera and diptera larvae).
Desert
University of Tehran
2008-0875
20
v.
2
no.
2015
117
121
https://jdesert.ut.ac.ir/article_56475_b5fa9548018bff0fac9e28ee779d4356.pdf
dx.doi.org/10.22059/jdesert.2015.56475
Simulation of climate change in Iran during 2071-2100 using PRECIS regional climate modelling system
Iman
Babaeian
Head of Climate Change Division, National Climate Center
author
Raheleh
Modirian
Member of Climate Change Devision, National Climate Center
author
Maryam
Karimian
Member of Climate Change Devision, National Climate Center
author
Mahdi
Zarghami
Faculty member of Civil Engineering, Tabriz University
author
text
article
2015
eng
Parameters such as future precipitation, temperature, snowfall, and runoff were modeled using PRECIS regionalclimate modeling system in Iran with the horizontal resolutions of 0.44×0.44°C in latitude and longitude under SRESA2 and B2 scenarios. The dataset was based on HadAM3p during the periods of 1961-1990 and 2071-2100. Theoverall precipitation error of the model in the period of 1961-1990 was 5.3%. Minimum errors were found to be overAzari, north-central, and Kordi regions. Maximum and minimum monthly precipitation errors were found inSeptember and May, respectively; but, minimum and maximum seasonal biases were found in spring and winter with-0.1 and -17.2% errors, respectively. Results revealed a decrease in mean annual precipitation toward the end of the21st century by 7.8 mm in B2 scenario and 10.1 mm in A2 Scenario with maximum regional decrease of 100 mm inthe southeast of the Caspian Sea. The decrease in precipitation was higher for A2 scenario, whereas it was minimumfor B1 scenario. Mean annual temperature of Iran during 2071-2100 would be projected to increase by 4.5-5.5°C inA2 scenario and 3-4°C in B2 scenarios compared to 1961-1990. It was shown that mean annual changes in runoffover the country were negligible both in A2 and B2 scenarios. Maximum annual amount of runoff increase was foundover western part of the Caspian Sea, Zagros and Alborz mountain chains by 6.4-15. 8mm. Results also indicated thatannual snowfall would decrease by the maximum amount of 22.9-23.7 cm over Zagros and Alborz mountain chains.
Desert
University of Tehran
2008-0875
20
v.
2
no.
2015
123
134
https://jdesert.ut.ac.ir/article_56476_ca0d15a201b57f8cf63665e55ebbf0e3.pdf
dx.doi.org/10.22059/jdesert.2015.56476
Determination of optimized sediment rating equation and its relationship with physical characteristics of watershed in semiarid regions: A case study of Pol-Doab watershed, Iran
Ali
Talebi
Faculty of Natural Resources, Yazd University, Yazd, Iran
author
A.
Bahrami
Faculty of Natural Resources, Yazd University, Yazd, Iran
author
M.
Mardian
Faculty of Natural Resources, Yazd University, Yazd, Iran
author
J.
Mahjoobi
Yazd Regional Water Authority, Yazd, Iran
author
text
article
2015
eng
Managers always consider the precise estimation of sediments in watersheds due to various conditions, such assoil and water resources management, construction, infrastructure and economical and social issues. In this condition,an optimized determination of sediment rating equation (typical method until now for sediment yield estimation) isessential to investigate sediment yield in rivers. In this study, the best sediment rating equation was determined forfour hydrometric stations of Pol-Doab watershed in Markazi province using sediment rating curves types (singlelinear,multi-linear, mean loads) together with bias correction factors (FAO, Quasi-Maximum Likelihood Estimator[QMLE], Smearing, Minimum Variance Unbiased Estimator [MVUE] and β). The results showed that the optimizedequation in stations is the mean loads (MVUE), which can used for prediction of sediment yield in annual scale.Moreover, FAO factor is more accurate for the estimation of sediment yield in high variability conditions formonthly, weekly and daily scales. According to the obtained results, accurate representation of variability intensity ofsediment yield is associated with the rating curves types, since the monthly rating curve is more accurate. Also, theresults indicated that the watershed average slope has direct relation with b coefficient of rating equation, and whenusing this parameter, the rate of sediment yield can be determined for month, season and hydrological periods. Basedon the obtained results, with increase in the watershed average slope, the slope of suspended sediment concentration(SSC) equation is also increased.
Desert
University of Tehran
2008-0875
20
v.
2
no.
2015
135
144
https://jdesert.ut.ac.ir/article_56477_af59e52d4f7309a4a140886529379f1e.pdf
dx.doi.org/10.22059/jdesert.2015.56477
The most important climatic factors affecting distribution of Zygophyllum atriplicoides in semi-arid region of Iran (Case Study: Isfahan Province)
Samira Sadat
Fatemi
Faculty of Desert Studies, Semnan University, Semnan, Iran
author
Mohammad
Rahimi
Faculty of Desert Studies, Semnan University, Semnan, Iran
author
Michele
Bernardi
Food and Agriculture organization of the United Nations, Viale delle terme di Caracalla IT-00153, Rome, Italy
author
text
article
2015
eng
Zygophyllum atriplicoides is one of the important species of Iran rangelands that has special importance owing to some properties like high distribution rate, coverage percentage, density, and plant biomass that make it possible to supply a part of forage needed by livestock during spring and winter as well as to avoid soil degradation against water and wind erosions. This research tries to study the most important climatic factors affecting distribution of Z. atriplicoides using multivariate statistical methods and selecting ecological important 69 variables in Isfahan province. Four factors, such as cooling temperature, precipitation, cloudiness, and wind were determined by the factor analysis method and variables variance of 34.45, 29.43, 11.79, and 9.06 were obtained, respectively totally represents 84.74 of the changes. The mean of factor scores and climatic variables in three populations of the Z. atriplicoides species as the dominant species, Z. atriplicoides species as the associated species and regions without the Z. atriplicoides species were determined. Furthermore, the factor score matrix was used as the input of the hierarchical cluster analysis and 6 climate zones were identified in Isfahan province. The most important climatic factors affecting the species distribution were determined by incorporating the vegetation map, factors map, and climatic zones. The effect of altitude was also analyzed in the species distribution. Results showed that the temperature factor is the most important climatic factor affecting distribution of the species in the Isfahan province and the precipitation factor influences the species distribution. Also, the effect of altitude and soil salinity on analysis of Z. atriplicoides populations could not be ignored.
Desert
University of Tehran
2008-0875
20
v.
2
no.
2015
145
156
https://jdesert.ut.ac.ir/article_56478_d4ed331b2a800cf41910811df0dd0380.pdf
dx.doi.org/10.22059/jdesert.2015.56478
Climate diversity in line with agroforestry systems: studying technicalities of agroforestry systems and allied components in two diverse climatic regions (Warm climate vs. cold climate) (Case study: Kazeroun & Sepidan in Fars Province, I.R.Iran)
Pardis
Goudarzian
Faculty of Desert Studies, Semnan University, Semnan, Iran
author
Mohammad Reza
Yazdani
Faculty of Desert Studies, Semnan University, Semnan, Iran
author
text
article
2015
eng
There has been some decline in the land potential capacity in many developing countries, and depending on location,the multi objective management strategy of Agroforestry can make effective use of natural resources to be feasible.Environmental principles which are effective on Agroforestry systems and their components, together with climaticfactors, are the important parameters which been evaluated in this study. Two cities, Kazeroun (with warm climate) andSepidan (with cold climate) in Fars province, were chosen for the purpose of this research, and after proper identificationand classification of the Agroforestry systems, the effects of climatic factors were analyzed. Nineteen points wereidentified in these two cities by field investigations, with each type of Agroforestry systems and their correspondingcomponents determined in each point. From the results, most of the systems in Kazeroun, characterized with warmclimate, were Agrosilvopastoral, while Sepidan with a characteristic cold climate was the Agrosilvicultural system. Also,the components of each system clearly changed with change in climate, owing to the great importance of the livestock andcrop components in Kazeroun and Sepidan, respectively. In general, it can be concluded that the impact of climatic factorson Agroforestry systems and their components has been approved in this study, and the results can be applied indeveloping these systems in other regions.
Desert
University of Tehran
2008-0875
20
v.
2
no.
2015
157
166
https://jdesert.ut.ac.ir/article_56479_d4d064d725db5e3e8e2f299797452122.pdf
dx.doi.org/10.22059/jdesert.2015.56479
Low flow frequency analysis by L-moments method (Case study: Iranian Central Plateau River Basin)
Amir
Keshtkar
Desert management Dept., International Desert Research Center (IDRC), University of Tehran
author
text
article
2015
eng
Knowledge about low flow statistics is essential for effective water resource planning and management in ungauged orpoorly gauged catchment areas, especially in arid and semi-arid regions such as Iran. We employed a data set of 20 riverflow time-series from the Iranian Central Plateau River Basin, Iran to evaluate the low-flow series using several frequencyanalysis methods and compared the result of these methods in their ability to set low flows for the conservation ofinstream water uses. Theoretical frequency distributions including the log-normal, three-parameter lognormal, Gumbel,Pearson type III, and log Pearson type III were applied with the low-flow series. Goodness-of-fit tests including Lmomentand conventional moment methods for the observed data were applied to identify the best distributions. For eachdistribution, the calculated values of the residual sum of squares (RSS) was applied to compare between the conventionalmoment and L-moment methods, and the best method was selected to determine the most appropriate probabilitydistribution. The lowest RSS values were used to select the best distribution for each station. Then, T-year low-flow serieswas estimated using the best probability distribution. Our results suggested that, for annual low flows, based on thecomputed RSS, Pearson type III, log Pearson type III, Gumbel distributions, and L-moment method were suitablydistinguished for 85%, 10%, and 5% of the stations, respectively. Finally, Compared to the conventional moment method,L-moments method was found to be more adequate to identify low-flow series probability distributions in the IranianCentral Plateau River Basin, while Pearson type III was found to be the best probability distribution for modelingminimum flow series in the study area.
Desert
University of Tehran
2008-0875
20
v.
2
no.
2015
167
175
https://jdesert.ut.ac.ir/article_56480_6eeaa5fc9a6bdc22bbf32ee7764f1cec.pdf
dx.doi.org/10.22059/jdesert.2015.56480
Modeling of streamflow- suspended sediment load relationship by adaptive neuro-fuzzy and artificial neural network approaches (Case study: Dalaki River, Iran)
Mohammad
Tahmoures
PhD Student, Faculty of Natural Resources, University of Tehran, Karaj, I.R. Iran
author
Ali Reza
Moghadamnia
Associate Professor, Faculty of Natural Resources, University of Tehran, Tehran, Iran
author
Mohsen
Naghiloo
MSc. Graduate, International Desert Research Center, University of Tehran, Tehran, Iran
author
text
article
2015
eng
Modeling of stream flow–suspended sediment relationship is one of the most studied topics in hydrology due to itsessential application to water resources management. Recently, artificial intelligence has gained much popularity owing toits application in calibrating the nonlinear relationships inherent in the stream flow–suspended sediment relationship. Thisstudy made us of adaptive neuro-fuzzy inference system (ANFIS) techniques and three artificial neural networkapproaches, namely, the Feed-forward back-propagation (FFBP), radial basis function-based neural networks (RBF),geomorphology-based artificial neural network (GANN) to predict the streamflow suspended sediment relationship. Toillustrate their applicability and efficiency,, the daily streamflow and suspended sediment data of Dalaki River station insouth of Iran were used as a case study. The obtained results were compared with the sediment rating curve (SRC) andregression model (RM). Statistic measures (RMSE, MAE, and R2) were used to evaluate the performance of the models.From the results, adaptive neuro-fuzzy (ANFIS) approach combined capabilities of both Artificial Neural Networks andFuzzy Logic and then reflected more accurate predictions of the system. The results showed that accuracy of estimationsprovided by ANFIS was higher than ANN approaches, regression model and sediment rating curve. Additionally, relatingselected geomorphologic parameters as the inputs of the ANN with rainfall depth and peak runoff rate enhanced theaccuracy of runoff rate, while sediment loss predictions from the watershed and GANN model performed better than theother ANN approaches together witj regression equations in Modeling of stream flow–suspended sediment relationship.
Desert
University of Tehran
2008-0875
20
v.
2
no.
2015
177
195
https://jdesert.ut.ac.ir/article_56481_72c4db269ef5befa67278f3a3d4f1522.pdf
dx.doi.org/10.22059/jdesert.2015.56481
Simulation of rice production under climate change scenarios in the Southern coasts of Caspian Sea
Fatemeh
Rabbani
Natural Geography Department, Faculty of Geography, University of Tehran, Tehran, Iran
author
Hossein
Mohammadi
Natural Geography Department, Faculty of Geography, University of Tehran, Tehran, Iran
author
Ghasem
Azizi
Faculty of Agricultural Science and Engineering, University of Tehran, Karaj, Iran
author
Daruosh
Mazaheri
Natural Geography Department, Faculty of Geography, University of Tehran, Tehran, Iran
author
text
article
2015
eng
Climate change has direct and indirect consequences on crop production and food security. Agriculture and cropproduction is one of the factors which depend on the weather conditions and it provides the human requirements inmany aspects. The objective of this study is to assess the impacts of future climatic change on irrigated rice yieldusing the CERES-Rice model in the Southern Coast of Caspian Sea under three climate change scenarios of Sra1b,Sra2 and Srb1. Required data for this research includes the meteorological, soil and crop management data. Themeteorological data include the daily data of minimum temperature, maximum temperature, solar radiation andprecipitation during 1981-2010 and Global Climate Models (HADCM3, ECHAM5, IPCM4, GFCM2, NCCCSM andINCM3) during 1971-2000. Soil and product management data provided from field experiment was conducted from2008 to 2009 at the Rice Research Institute in Rasht. Validating of Global Climate Models show that ECHAM5climate model has the highest correlation with the lowest error to simulate the future temperature and precipitation.We used ECHAM5 climate model coupled with a crop growth model for simulating of the effects of climate changeon rice protection. The results of prediction of climate change scenarios show that minimum and maximumtemperature will be ascending and precipitation will be decreasing in the Rasht station. Results of simulated yield andbiomass of the rice crop base on scenarios of Sra1b, Sra2 and Srb1 show that rice crop yield and biomass decreasewith increasing of mean temperature and decreasing of precipitation.
Desert
University of Tehran
2008-0875
20
v.
2
no.
2015
197
206
https://jdesert.ut.ac.ir/article_56482_fff3eaf9038814c223ec9e5641de8177.pdf
dx.doi.org/10.22059/jdesert.2015.56482
Column leaching experiments on saline soils of different textures in Sistan plain
Elahe Sadat
Hosseini
Department of Water Engineering, University of Zabol
author
Masoomeh
Delbari
University of Zabol, Department of Water Engineering
author
text
article
2015
eng
Salinization is the main characteristic of soils in arid and semi-arid regions which reduce the agricultural potential ofirrigated lands. Therefore, soil reclamation as well as determination of the leaching requirement for salt control is veryimportant for better plant growth. In this study, the effects of leaching on saline soils of Sistan region, southeast of Iranwere examined using unsaturated disturbed soil columns. The experiment was conducted on four texture types (loam,sandy clay loam, sandy loam and clay loam) and three replications. Soil samples were purred in polyvinyl chloride (PVC)cylinders and leaching procedures were conducted in 10 stages with up to 5 pore volumes. Effluent from each columnwas collected and evaluated in terms of Na+, K+, Ca2+, Mg2+ and EC. At the end of the study, soil columns were cut andtheir corresponding samples were analyzed for Na+, K+, Ca2+, Mg2+ and EC. The results of leaching experiments showedthat the water used in this study could reduce solute concentration and thus, this soil does not need any amendment. Formost soil textures, it was also observed that almost 85% of the salts were leached after the fifth stage of the leachingprocess. According to the results, ions entry into the effluent solution is fast in the coarse textured soils. So, the differencebetween the amounts of irrigation water needed to transport the salts and leach the saline soils can be attributed to thesoil texture. It seems that the main reason for these reactions is the cation exchange.
Desert
University of Tehran
2008-0875
20
v.
2
no.
2015
207
215
https://jdesert.ut.ac.ir/article_56483_3243deabcdcf23f8d858c2369ec96041.pdf
dx.doi.org/10.22059/jdesert.2015.56483
Investigating strategies for optimum water usage in green spaces covered with lawn
Maliheh
Rabbani
Department of Horticulture and Landscape, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
author
Fatemeh
Kazemi
Department of Horticulture and Landscape, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
author
text
article
2015
eng
Water supply of green spaces in arid areas is a major challenge. A high percentage of green spacescreate lawns, which are high water consumer landscapes. Due to the environmental, recreational andathletic values of lawns, they are considered as non-removable elements in urban green space development.This paper reviews and discusses strategies for efficient water usage in lawn areas using library studymethods. According to the results, first, it was recommended that water demands of turfgrasses arecalculated using precise scientific methods. Eleven strategies including selecting appropriate plant species,clipping from appropriate height, removing the thatch layer, using wastewater as an irrigation water source,the use of superabsorbents, application of regulated deficit irrigation, the use of subsurface irrigationsystems, replacement of lawns with appropriate ground cover plants, the use of surfactants and otherchemicals such as paclobutrazol and endophyte fungi, as individual or combined strategies were suggestedfor efficient water usage in turfgrass areas. These results, in some cases, can be used as executiveguidelines by green space professionals in order to reduce water usage in this sector and in other cases,they can be used as preliminary studies for research in the field of sustainable management of turfgrasses inarid and semi-arid areas.
Desert
University of Tehran
2008-0875
20
v.
2
no.
2015
217
230
https://jdesert.ut.ac.ir/article_56484_f1e8404574750eeb8eb311d25811a7ec.pdf
dx.doi.org/10.22059/jdesert.2015.56484
Measure and comparison of economic, social and ecological sustainability of farming systems in the Marvdasht plain
Hajar
Hassanshahi
Faculty of Agricultural Economics and Development, University of Tehran, Karaj, Iran
author
Hooshang
Iravani
Faculty of Agricultural Economics and Development, University of Tehran, Karaj, Iran
author
Zhila
Daneshvar Ameri
Faculty of Agricultural Economics and Development, University of Tehran, Karaj, Iran
author
Khalil
Kalantari
Faculty of Agricultural Economics and Development, University of Tehran, Karaj, Iran
author
text
article
2015
eng
Agricultural sustainability refers to the ability of a cropping system to produce, without causing irreversible damage tothe ecosystem. There is an increasing need to view cropping systems and identify management practices in a holisticindicator-based impact assessment. The main objective of this study was to compare and rank the cropping systems of theMarvdasht plain in Fars Province; in order to show the gap between them. To achieve this aim, sustainability were dividedinto four levels based on Composite Index(CI),which is useful for the identification of sustainability and includes threedimension: (1) economical, (2) social, and (3) environmental and consist of 11 indicators. Required data were collected byquestionnaire from 200 cropping farmers who were selected through a stratified sampling design from six regions locatedin Marvdasht plain. The computer software of SPSS was used to analyse the data. Indicators were normalized using thedivision by means technique and were weighted. The weightings were derived from Principal Component Analysis(PCA). CI was used to map the sustainability levels at the plain. According to classifying CI, four categories wereidentified, which zone 6 identified as being unsustainable, while two zones 2 and 3 were considered as belonging to therelatively unsustainable and the zone 5 was identified as relatively sustainable and the remaining zones (1,4) wereclassified as sustainable. We conclude that the usage of multidimensional and holistic CI for analysing sustainability ofcomplex cropping systems is extremely important.
Desert
University of Tehran
2008-0875
20
v.
2
no.
2015
231
239
https://jdesert.ut.ac.ir/article_56485_6545d18f3e47ec9d8b1e95352d0cc528.pdf
dx.doi.org/10.22059/jdesert.2015.56485
The necessity of transgenic technology in sustainable production
B.
YAzdi Samadi
Faculty of Agricultural Science & Engineering, University of Tehran, karaj, Iran
author
M.
Valizadeh
Faculty of Agriculture, University of Tabriz, Tabriz, Iran
author
B.
Baghban Kohnehrous
Faculty of Agriculture, University of Tabriz, Tabriz, Iran
author
text
article
2015
eng
It has been more than half a century that plant geneticists and breeders have been trying to assemble a combinationof genes in crop plants, in order to make them as suitable and productive as possible. Plant transformation technology incrop plants was first undertakenin the 1980s based on the ability of foreign gene integration into host plant genome andregeneration of transformed plant cells into whole plants. Soon after, transgenic plants were to be grown by farmers.Statistics show that farmers have started to cultivate genetically modified plants (GMPs) commercially since 1996.Between 1996 and 2012, the total surface area of land cultivated with GM crops has increased from 2 million hectaresto more than 170 million hectares in 29 countries. To this extent, some concerns have been raised by ecologists andconsumer organizations in West European countries based on the possibilities of horizontal and vertical gene flow ofantibiotic or herbicide resistance from transgenic plants into human intestinal bacteria and some weeds via outcrossing,respectively. Due to consumer and ecologist concerns, different approaches have been developed to eliminate marker(and/or reporter) genes from the nuclear or chloroplast genome after selection. Some of these proposed methods are:1. Replacing selectable markers with screenable ones.2. Elimination of marker genes by co-transformartion followed by classic recombination and selection.3. Excision of marker gene by some site-specific recombinases.4. Separation of the transgene and selectable marker by transposable elements.5. Avoiding gene pollution by chloroplasts genetic engineering followed by elimination of selectable marker.
Desert
University of Tehran
2008-0875
20
v.
2
no.
2015
241
244
https://jdesert.ut.ac.ir/article_56486_1293e0fad36912ec459ec252a56b13f4.pdf
dx.doi.org/10.22059/jdesert.2015.56486
Effect of drought stress and salicylic acid on yield and mucilage content of the medicinal herb Plantago ovata Forssk
Hosein
Shekofteh
Department of Soil Science, Faculty of Agriculture, Vali-e-Asr University, Rafsanjan, Kerman, Iran
author
Hamid
Shahrokhi
Department of Soil Science, Faculty of Agriculture, Vali-e-Asr University, Rafsanjan, Kerman, Iran
author
Elham
Solimani
Department of Soil Science, Faculty of Agriculture, Vali-e-Asr University, Rafsanjan, Kerman, Iran
author
text
article
2015
eng
Since there is limited information on the simultaneous effect of drought stress and salicylic acid on yield and mucilagecontent of the medicinal herb, Plantago ovata Forssk is available, a pot experiment was conducted in factorial form basedon a randomized complete block design with three replications in Jiroft, Kerman Province, south of Iran. As the firstfactor, drought stress included four levels of irrigation: 100℅ field capacity (FC) (no stress), 75℅ FC (low stress), 50℅FC (medium stress) and 25℅ FC (high stress). In the second factor, salicylic acid had four levels: 0, 0.01, 0.5 and 1 mM. The results showed that maximum yield and yield components of P. ovata Forssk were obtained with 100℅ FC andsimultaneous application of 1 mM salicylic acid. Minimum amounts of yield and yield components resulted fromirrigation based on 25℅ FC with no application of salicylic acid. Such an outcome revealed the significant role of salicylicacid in increasing the tolerance of Plantago ovata Forssk to drought stress.
Desert
University of Tehran
2008-0875
20
v.
2
no.
2015
245
252
https://jdesert.ut.ac.ir/article_56487_468da7d702df8106fd54a99f0526dd7d.pdf
dx.doi.org/10.22059/jdesert.2015.56487