جستجوی مقالات مرتبط با کلیدواژه "خوزستان" در نشریات گروه "زیست شناسی"

Two species, green toad (Bufotes viridis) from true toads (Bufonidae) family and Marsh frog (Pelophylax ridibundus) from true frogs (Ranidae) family have the most distribution in Khuzestan province. These species have many taxonomic problems and the chromosomal studies have been done in the country are few. In the field studies, 28 samples of anura including 17 green toads and11marsh frogs were collected from northwest and south of Khuzestan province (Shush, Khorramshahr and Hendijan). Sampling was done between the summer of 2018 and the summer of 2019. Chromosome studies showed all green toads have 22n=22 chromosomes that were classified into two groups.  The first group included 6pairs of large chromosomes and the second group composed of 5pairs of small chromosomes. In the toads of all three studied regions, the fourth and seventh pairs of chromosomes were submetacentric and the rest chromosomes were metacentric. Results showed all collected marsh frogs have 2n=26 chromosomes, which were divided into two groups. The first group included 5pairs of large chromosomes and the second group had 8 pairs of small chromosomes. The karyotype formula of the frogs of the three sampling areas are not the same. The karyotype formula of Khorramshahr, Shush and Hendijan frogs are 8m+1sm+4st, 7m+3sm+3st and 6m+6sm+1st, respectively. Sex heteromorphic chromosomes were not observed in any of the collected samples. Current study on marsh frogs and its comparison with other investigations shows a significant diversity in terms of karyotype in the country, which strengthens the possibility of the existence of a species complex.

Horizontal vision is the maximum horizontal distance that a person with the naked eye can clearly detect features on the ground.The location of Khuzestan provinc at the top of the basin of dusty winds known as the north wind, which spread dust from the deserts of Syria and Iraq to southwestern Iran, frequently reduces the horizontal visibility in these areas The aim of the present study is to study the trend of horizontal vision changes using horizontal vision data and mean values of aerosol optical depth. The data used in the present study include daily horizontal vision data of synoptic stations in Khuzestan province in the period 1998 to 2020. Ridit statistical method was used to analyze the horizontal vision data. Horizon of view in the studied stations was grouped into five categories and the frequency of each category was determined and the value of Ridit was calculated for each category. Then the relevant diagrams and maps were drawn. Also, the fluctuations of the average monthly AOD in the statistical period under study in the geographical location of meteorological stations were calculated and their values were extracted. Comparison of the graphs of the studied stations shows that in all stations except Masjed Soleiman station, the horizontal visibility has a decreasing trend.

Heavy metals, due to their indestructible nature, pose a serious threat to the health of aquatic animals as well as humans if a high concentration of them accumulates in the tissues of aquatic organisms. For this purpose, the present study was done with the aim of investigating native Bunni and Shabout fishes in tropical fish breeding farms of Khuzestan province with the perspective of contamination by heavy metals and risk assessment for consumers. In present study, the concentration level of thirteen heavy metals (arsenic, cadmium, cobalt, chromium, copper, iron, mercury, manganese, molybdenum, nickel, lead, tin and zinc), in the muscle tissue of (Mesopotamichthyssharpeyi) and (Barbus gryous) was measured. The results of this study showed that there were no significant difference between the concentration of heavy metals measured in Bunni and Shabout fishes. The findings of the research indicated that iron and arsenic had the highest and lowest concentrations in the muscle tissue of Bunni and Shabout fishes, respectively. Comparison of measured heavy metals with international health standards showed that the concentration of all metals except lead were significantly lower than the permissible limit (p < 0.05). The concentration of lead was significantly higher than the permissible limit (p < 0.05). The assessment of health risk showed that daily and continuous consumption of these products by consumers is completely safe, except for cadmium and lead and there is no risk for them. The average concentration of all measured metals except lead were lower than international standards. The estimation of daily intake of all measured heavy metals except cadmium and lead were less than global standards. The estimation of daily intake in all metals except cadmium and lead showed that the consumption of Shabout and Bunni fish currently does not pose a risk to human health, however, in order to prevent possible contamination in the future, management should pay more attention to these pollutants and their possible sources.

The science of ethnobotany is the collection of reliable data about the medicinal uses of plants in different cultures, which can be the basis for the discovery of new drugs. This research was conducted with the aim of identification and introduction of native medicinal use and ethnobotanical indicators of plant species of Susan in Susan region of Khuzestan province in Iran with an area of 1016 ha. Using a questionnaire, the data was collected from 80 (55 men and 25 women) native participants in the age range of 30-75 years old. Also, 109 species of medicinal plants belonging to 40 plant genera were collected and identified from Susan region in the northwest of Izeh city, Khuzestan, Iran. According to the obtained results, Asteraceae with 16 species, Lamiaceae with 12 species, Apiaceae with 8 species, Fabaceae with 7 species, and Brassicaceae with 6 plant species had the most medicinal uses. The results of the investigation of the traditional use of plants in this region showed that medicinal plants are mainly used for the treatment of digestive diseases, respiratory diseases, skin diseases, and blood circulation diseases (fat, high blood pressure, and blood sugar), urinary tract diseases, and as a sedative.

Nowadays, climate change causes abundant worries in different spots in the world. For this reason, a study was conducted to find the trace of this global phenomenon in Khuzestan province. Therefore, we used meteorology data including temperature parameters, rainfall, evapotranspiration and relative humidity for 15 weather stations in a period of 21 years (1996-2016) and Mann Kendal graph to determine the trend. The result illustrates that there is a meaningful downward trend for rainfall parameter in SafiAbad, Hendijan, Masjedsoleiman and Bandar-E-Mahshar with confidence level of 95% and Omidiyeh with confidence level of 99%. Moreover, there is a meaningful upward trend with confidence level of 95% in tempe-rature parameters in most stations, while this level is 99% in Bostan, Hendijan and Izeh. In addition, a meaningful upward trend in evapotranspiration in two station of Bostan and SafiAbad with confidence level of 95% and 99% and a meaningful downward trend with confidence level of 99% for Shushtar, Izeh, Abadan, Masjedsoleiman and Ahwaz as well, is visible. There is a meaningful downward trend in relative humidity in Bostan, SafiAbad, Izeh, Omidiyeh and Masjedsoleiman, which all present the climate change effect in region.Climate change is one of the most important challenges in the 21st century. Global warming has caused very unstable changes in climate parameters such as: changes in rainfall patterns and frequency and intensity of climate changes. The issue of climate change has become one of the main concerns of scientists related to atmospheric sciences due to its impact on various dimensions of human life and the dependence of human activities on it, and many researchers are trying to understand the various dimensions of this important phenomenon. The change in climatic elements, especially temperature and precipitation, is one of the most important signs of this phenomenon. Changes in temperature and precipitation in different parts of the earth do not follow the same trend, and climate change does not necessarily mean simultaneous changes in precipitation and temperature. The amount, distribution and temporal and spatial changes of precipitation and temperature are essential factors for decision-making, management, planning and design, especially in areas such as Iran, which is geographically located in the 28 to 48 degree north latitude and It has a dry and semi-arid climate. In order to detect the trend in the time series of water and meteorological variables, various tests are used, and these tests can be divided into two categories, parametric and non-parametric. Parametric tests are more powerful in detecting trends than non-parametric tests, and when using them, the data should be random and have a normal distribution. On the other hand, non-parametric tests can be used if the data is random and are not sensitive to the normality of the data. Mann-Kendall's test is a non-parametric test that is used in researches to investigate the trends of water and meteorological variables. To carry out this research, climatic data (average rainfall, average evaporation and transpiration, average humidity and temperature parameters) prepared by the meteorological organization of Tehran province for a statistical period of 21 years from 1996 to 2016 have been used. Mann-Kendall test was used to analyze the trend of climatic parameters, which will be explained in detail below.• Mann-Kendall non-parametric testThis test was first presented in 1945 by "Mann" and then developed by "Kendall" in 1966. This test does not require a normal frequency distribution or linear behavior of the data, and it works very strongly compared to the data that deviates from the linear behavior and is used to evaluate the trend (Darabi et al., 2015). In this test, the null hypothesis (H0) and the opposite hypothesis (H1) are respectively equivalent to no trend and the presence of a trend in the time series of observational data. Mann-Kendall diagram test:The steps of the test are briefly as follows:We rank the data and calculate the ti statistic, which is defined as the ratio of rank I to its previous ranks, and then we obtain the cumulative frequency of the statistic ( ). Mathematical expectation, variance and Mann-Kendall index are calculated based on the following formulas (Zahedi et al., 2016):In these relationships, ni is the time order of the data. To check the changes, the index Ui' should also be calculated: rank the data and determine the statistic t'i, which is defined as the ratio of rank I to its next ranks, and then calculate the cumulative frequency of t'i we do The mathematical expectation, variance and index Ui' are as follows:In the above relationships, N is the statistical sample size under study. The intersection of the index Ui and Ui' is a sign of a sudden change in the time behavior of a statistical series. The non-intersection of the curve or their placement within the 95% confidence range does not indicate significant changes in the data, but if the mentioned lines intersect within the critical range of 1.96 and 2.58 and then leave the critical range, it is a sign of a sudden change and a significant trend at the 95% and 99% confidence levels, respectively. If the U curve moves to the positive side, it has a positive trend, otherwise it has a negative trend. Crossings outside the critical range indicate a sudden change in the behavior of the series (Alijani et al., 2009).In general, the results showed that during the studied statistical period, rainfall in all stations had a decreasing trend. Also, the minimum and maximum temperature parameters have been increasing in most of the stations. The parameters of evaporation and transpiration and relative humidity in most of the stations had a non-significant decreasing trend. Based on the results of Mann-Kandall charts, it was found that Safi Abad, Omidiyeh and Handijan stations were more affected by these changes than other stations. It is obvious that dealing with the effects of climate change and its consequences, such as the increase in the temperature of the earth's surface or the decrease in rainfall, requires a detailed investigation of the causes of this phenomenon and the provision of appropriate solutions in order to prevent endangering food security, increasing soil erosion, desertification and other problems.

The only navigable river is the Karun River in Iran. Karun shipping history dates back to Nasser al-Din Qajar Shah. Climate change and drought, harvests more water and reduce its capacity, the existence of new railways and highways as the main competitors of cargo from the port of Mahshahr and Khorramshahr to Ahvaz due to the boom in river water transport has been falling. There are few studies on water transport in Karun river. In this study, some of their results are discussed in general. Then, based on the acceptance of the latest research, the most important physical barriers to river transportation have been identified and their remediation strategies adapted to the current situation. Then shipping Signs required of navigation and auxiliary's equipment for sailing have also been offered. Previous studies included :(Iranian structural consulting engineers, 2004; Adabdanan Consulting Engineers, 2004) and Especially (Scott Wilson and Piesold, 2005) It has been attributed to the heavy losses of water transportation, especially in the high tonnage of annual freight. The most recent study, ongoing surveys at the Khuzestan Water and Power Organization (Mansouri Kia, 2018) show that the transport medium (in the pessimistic scenario optimistic scenario about 700 thousand tons and 2133 thousand tons in the target year 1425), together with previous studies is the development of tourism can be no economic losses. Water transport is the base year 2020. Heavy financial losses were previously assumed for river transportation. The most important results of recent research suggest that these losses are reduced by modifying the design vessel dimensions.Another important result of the present study is identifying the physical problems for the Iranian rivers transportation and to provide solutions (except for the sediment removal problem that is being investigated at another study). Applying the research results on solving physical barriers and financial support by private investment (or other financing options), revive water transportation in Karun it is possible.

The aim of this study was to estimate the amount and species composition of discards in bottom trawl fisheries in the Bosif fishing ground in the coastal waters of Khuzestan. Furthermore, the biological parameters of discarded species were assessed. Specimens were collected from commercial catch data of trawl vessels in three seasons, autumn and winter 2017 and summer 2018. The results showed that discarded samples included 33 species from 28 families. Orangefin Pony fish and striped piggy species were the most frequent species in this study. The results also showed that the mean length of most of the discards species was below 30 centimeters. The amount of discards per unit of catching effort was 57.33±9.87, 27.50±16.64 and 32.33±7.50 in the autumn, winter and summer seasons, respectively. The catch per surface area in autumn, winter and summer were 2.77 ± 0.064, 0. 73 ±0.39 and 1.73 ± 0.44 kg/nm2, respectively. The results showed that CPUE and CPUA in winter were significantly higher than those in autumn and summer (p<0.05). In general, the results of this study represent high fishing pressure on ecologically important species in Bosif fishing ground especially in their critical life cycle which may affect local ecosystem structure and function in future.

The water frog (P. bedriagae) is considered as an important part of the food network balance in most ecosystems, it is affected by many environmental stresses and the distribution of its populations is strongly dependent on ecological factors. In this study, extensive sampling of swamp frog populations in the northern and southern parts of Khuzestan province was performed and the analysis of changes in morphological traits under the influence of geographical separation was performed. The results showed the presence of sexual morphology between morphological traits (T-test, ANOVA). In addition, the results of MANOVA and T2 Hotelling test showed demographic separation between males and the absence of demographic separation in females in the northern and southern regions. To prove such a difference, multivariate principal component analysis (PCA) was performed. According to the results of the test, the male populations were divided into two separate groups, while in the female populations only a few were scattered and the rest formed a single group. Finally, the cluster analysis of the studied populations was divided into two groups based on morphometric traits, the population of Shush region and the population of the southern regions and parts of the northern regions. According to the results, despite the two morphologies and demographic separation in males based on morphological traits, demographic separation was not fully confirmed. Thus, despite the geographical separation of the populations of the two northern and southern regions of Khuzestan province, they still show a single population in terms of morphological traits.

This research was aimed to investigate the concentration of heavy metals (including copper, vanadium, lead, and nickel) in water, sediment, muscle, and liver tissues of Sillago sihama living in the Khour-e-Mousa, Khuzestan province. Samples were picked randomly from three stations during winter and summer and the concentration of heavy metals was measured using atomic absorption spectrometry (flame and flameless GF AAS). Based on the results, the bioaccumulation index (BI) of liver tissue for these four elements was measured 183.33, 0.05, 0.29, and 2.35 in winter, and 21.7, 0.07, 0.25, and 1.05 in summer, respectively. Moreover, the BI for muscles was measured 130, 0.02, 0.07, and 1.45 in winter and 18.3, 0.02, 0.07, and 0.49, in summer, respectively. The results showed that there was a significant linear relationship between the concentration of heavy metals in sediment with their accumulation rate in muscle and liver tissues of Silver sillago. According to the results of this study, the ecological risk potential index (RI) was however rated low at the ecological risk range, since, Khour-e-Mousa is known as one of the most sensitive ecological and environmental areas and there are signs of an increasing trend of metal pollution. It raises serious concerns for the region in terms of ecology and public health.

Mesquite (Prosopis juliflora) belonging to Fabaceae that is originally a Native American plant, was brought to Iran to develop urban green spaces in the past decades. At present, it is an alien invasive plant and occupies a wide range of natural habitats in Khuzestan province (southwestern Iran). The aim of the present study was the assessment of genetic diversity in some populations of this species in Khuzestan province using Conserved DNA Derived Polymorphism (CDDP) molecular markers. Twenty samples from four distinct populations were evaluated using 20 CDDP primers. The resulted data were analyzed by NTSYS, Popgene and GenAlex softwares. The primers generated 212 bands, from which 194 bands (91.94%) were polymorphic. The highest and lowest means of genetic diversity were 0.221 and 0.114 for the populations of Khorramshahr and Ahvaz, respectively. Clustering analysis using Jaccard's similarity coefficient and UPGMA method classified the samples in two separate groups at 22% similarity level, reflecting their genetic variations. Molecular Variance Analysis also showed that the genetic diversity in intra-population was higher (51%) than inter-population (49%). This study indicated the high potentiality of the CDDP marker for assessing genetic diversity of Prosopis juliflora populations.

The most essential oil compounds in the A.sieberi L., A.aucheri L. and A.vulgaris L. were alpha-pinene, camphene, sabinene, limonene, artemisia-ketone, borneol, caryophyllene, germacrene-D and beta-eudesmol.  The purpose of this study was to investigate the effects of climatic conditions of two different regions of Khuzestan province (Masjed Soleiman and Izeh) and phenological stages (vegetative, flowering and seeding stages) on ​​the quantitative and qualitative characteristics of essential oil of three species of Artemisia (sieberi, aucheri and vulgaris) belonging to the Asteraceae family. This research was conducted in a completely randomized design in 3 replications. After collecting the shoots of plants in different stages, the essential oil was extracted by steam distillation and GC and GC / MS was used to identify the compounds. The most effective essential oil compounds were alpha-pinene, camphene, sabinen, limonene, artemisia-ketone, borneol, caryophyllene, germacrene-di and beta-odemsol. In addition, the amounts of volatile components and monoterpene hydrocarbons such as alpha-pinene and limonene in essential oils decreased from Masjed-Solieyman (tropical) to Izeh (temperate), however the percentage of sesquiterpene hydrocarbons such as caryophyllene increased. Therfore to obtain the most essential oil in the three studied species of Artemisia, harvesting in tropical climate at the beginning of flowering stage is suggested.

The city of Ahvaz is considered the most polluted city in the world by blowing dust from neighboring countries which makes this study important. The results show that the smaller the particles, the more permeable they become and pass through the respiratory filters and causing disease. In this study, the effect of fine particulate matters in different cities of Khuzestan province of Iran was compared on the liver histology and oxidative stress enzymes of male rats. 30 adult male rats were divided into six equal groups including control, Ahvaz, Ramhormoz, Andimeshk, Abadan, and Susangard which were treated for two months. The results of serum oxidative stress enzyme activity increased only for the glutathione peroxidase in Ramhormoz and Abadan groups. The histological examination of liver revealed bleeding, mild hyperemia, and changes in hepatocyte cells. The nuclear area in central vein region, hepatocyte area in portal, and vein regions showed significant changes. Moreover, kupffer cell number of the portal region significantly increased in Ahvaz, Abadan, and Andimeshk groups. Therefore, due to different heavy metals composition, fine dusts have different effects on blood and liver parameters which depend on their amount and duration of exposure.

Particles in fine dust have the first rank of carcinogens, making their study necessary. The previous results showed that particles with aerodynamic diameters of 2.5 and 10 micrometers are more permeable and pass through respiratory filters and are the main cause of damage. In this study, the effect of fine particulate matters in different cities of Khuzestan province of Iran on blood cells of male rats was compared. Thirty adult male rats were divided into six equal groups, including control, Ahvaz, Ramhormoz, Andimeshk, Abadan, and Susangerd and were treated for two months. The results of blood cell analysis showed an increase in the number of white blood cells, especially lymphocytes in Ahvaz group, while the volume of platelets was significantly reduced. In most groups, a significant decrease was observed in RDW and the amount of hematocrit in Ramhormoz and Susangerd groups showed a significant increase compared to the control group. Therefore, given the different heavy metals composition, fine dusts have different effects on blood parameters, depending on their amount and duration of exposure.

Study on ecology and biology of scorpions is very limited and the basis of this information the country, Iran, is the identification of habitats, and morphology of scorpions in different regions of Orthochirus species are widely distributed in the world. So far, 17 species have been identified throughout the world, of which 7 species have been found in different regions of Iran. In this study, Orthochirus specimens were collected from different regions of Khuzestan province and evaluated based on 27 morphometric values and 18 morphometric ratios. Four species, O. iranis, O. zagrosensis, O. farzanpay, and O. stackwelli were identified from different regions of Khuzestan province. Orthochirus. iranis and O. stackwelli had the most (41.6%) and the least (13.8%) frequencies, respectively, in the various regions of the province. The results of morphological studies and statistical analyzes on morphometric showed the complete separation of four types. Differences of species were confirmed based on the characteristics and ratios of the fourth segment of metasoma, carapace and telson sizes, the position of the median eyes, and pedipalp chela length and movable finger. The result of cluster analysis indicated that O. stackwell is morphologically distinct from other groups and had the most similarities between O. iranis and O. zagrosensis.

Skeletocronology is a reliable method for estimating the age but in amphibians little researches have been done in this field. In the present study, for the first time in the country of Iran, the age structure of the population, growth pattern and reproductive primary age were studied in the populations of marsh frog in the northern and southern regions of Khuzestan province. For this purpose, 20 female and male marsh frog samples were fished alive in the Khuzestan province and transferred to the laboratory. After biometric studies, the specimens were prepared and after the removal of the bones of the limbs, bone samples were passaged as routine histotechnique. The number of growth stop lines and samples age were determined. In order to determine the relationship between age and body weight, body length and age with eye lens weight, the data was analyzed statistically. the maximum number of loops counted in this population is . The adult age of males of northern and southern, males of the northern and males of the southern regions was determined 2,2 and 3 years respectively. with increasing age of females, the co-integration rate of females was reduced which is explainable by the reduction in bioavailability due to the increase in biological age. According to the results, there was a significant correlation between age of animals with body and  eye lens weight, but there was no significant correlation between age of  animals with body length, except a limited number of males in northern regions (P<0.05) There was.

Nowadays, climate change causes abundant worries in different spots in the world. For this reason, a study was conducted to find the trace of this global phenomenon in Khuzestan province. Therefore, we used meteorology data including temperature parameters, rainfall, evapotranspiration and relative humidity for 15 weather stations in a period of 21 years (1996-2016) and Mann Kendal graph to determine the trend. The result illustrates that there is a meaningful downward trend for rainfall parameter in SafiAbad, Hendijan, Masjedsoleiman and Bandar-E-Mahshar with confidence level of 95% and Omidiyeh with confidence level of 99%. Moreover, there is a meaningful upward trend with confidence level of 95% in tempe-rature parameters in most stations, while this level is 99% in Bostan, Hendijan and Izeh. In addition, a meaningful upward trend in evapotranspiration in two station of Bostan and SafiAbad with confidence level of 95% and 99% and a meaningful downward trend with confidence level of 99% for Shushtar, Izeh, Abadan, Masjedsoleiman and Ahwaz as well, is visible. There is a meaningful downward trend in relative humidity in Bostan, SafiAbad, Izeh, Omidiyeh and Masjedsoleiman, which all present the climate change effect in region.

Aromatic herbs are considered the most valuable antioxidant source in nature. In this research, 3 different ecotypes of Oliveria decumbens vent. were collected from three important regions in Khuzestan province, including Behbahan, Shushtar and Masjed Soleyman in flowering stage. Essential oils were extracted by hydrodistillation method (Clevenger apparatus) and d were analyzed by GC /Mass and the antioxidant activities were specified by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Results were showed that the highest thymol (29.67) and carvacrol (27.88%) were dominanted in Behbahan region oil. The percentage of degradation of DPPH free radicals in different concentrations of essential oil including 50, 100, 200, 300, and 400 μl were calculated to determine the antioxidant activity of the essential oil. The IC50 values were calculated 34.21, 26.85 and 21.23, respectively from Shushtar, Masjed Soleyman and Behbahan regions. Finally, Behbahan ecotype with the highest source of thymol, carvacrol and antioxidant properties can be considered as a new best natural source of antioxidant supply.

In this study age, growth and maturity of Hilsa shad in Khuzestan province were analyzed. 394 number of fishes from marine habitat (Life-Boseif), estuaries (Bahmanshir and Arvand) and rivers (Bahmanshir and Karoon) from February 2014 to September 2014 were collected using commercial fishing with gill net. Total length and wet weight of each fish were measured with precision of 1 cm and 1 gram. Sagittal otoliths were extracted for age determination of the fish. Then abdominal cavity of each sample were opened for determining sex and maturity stage. Growth parameters were calculated using von Bertalanffy growth function (L∞=58.365, K=0.26, t0=-0.16). Phi-prime constant was obtained 2.95. Length and age at first maturity were obtained 27.32cm and 2.4 g respectively using logistic model to fit a and b parameters with observed data in spawning season.

The purpose of this study is to investigate the dust and predict the best time series models for the cities of Khuzestan province during the years 2019-2023. The statistical method of the library and using the annual data, eight cities selected from Khuzestan province to identify and predict the best time series models using the software Minitab17, spss19 Excel 2013. For this purpose, annual dust data from eight meteorological stations of Khuzestan province during the period of 1990-2010 were collected and analyzed using the ridge test of homogeneity of dust data. Using time series models of dust walnuts and the best model for identifying fitted dust, the accuracy and accuracy of the models were based on absolute error (MAE), absolute error (MAPE), root mean square error (RMSE average), and The BIAS standard has been approved. The results of the most suitable models of Dust Time Series for the cities of Masjed Soleyman and Behbahan are Halt Winters forecast model, Dezful city alone in the model of Arima (1.0.1) and Ahwaz, Ramhormoz, Aghajari, Abadan and Omidieh models Nemo is smoothly achieved. Also, the results of the dust show that the city of Omidieh with the highest difference of dust increases to 79 days and the city of Dezful reaches the lowest number with 9 days. And the rest of the cities are Abadan, Aghajari, Ramhormoz, Ahvaz, Masjed Soleyman and Behbahan, respectively, 75, 45, 45, 41, 36 and 25 days a year.

Diesel oil is the major product of crude oil. This product is the main pollutant of environment and has hazardous effects on the environment. Bioremediation is the best method for remediation of this pollutant, because this method use nature potential for remediation and also this method has a low cost.
In this study, for isolation of diesel-oil degrading bacteria sampling performed from contaminated regions. The prevalent diesel-oil degrading bacteria were identified by biochemical and molecular methods. Some properties in these bacteria were analyzed such as: hydrophobicity and emulsification activity. The percentage of diesel-oil degradation was assayed for each strain by Gas Chromatography (GC) and qualitative test.
In this research 34 diesel-oil degrading bacteria were isolated. From these strains 10 strains were selected according to diesel-oil degradation. These strains belong to Achromobacter¡ Enterobacter and Klebsiella. The half percentages of diesel-oil were removed by these strains in 10 days of incubation. The best strain for degradation of diesel was Enterobacter cloacae strain L2 (72%). The highest hydrophobicity is related toKlebsiella oxytoca strain K2 (76%) and the best emulsification activity belongs to Achromobacter denitrificans strain B2 (58 %).
Discussion and The results of this research confirmed that diesel degrading bacteria have sufficient diversity in soil contaminated in Iran. These bacteria have good potential for remediation of diesel pollution from soil.