فرزانه نیکوخواه

One of the sources of pollution in rivers is effluent discharge from fish farms, which decreases water quality for downstream usage. This study investigated the effects of trout farms’ effluent on the levels of physicochemical parameters in Sardab spring.

To assess contamination from the effluent, five trout farms along the margin of the river were selected. In summer and autumn 2016, this study analyzed the levels of physicochemical parameters of trout farm effluent, such as pH, temperature, dissolved oxygen, electrical conductivity, nitrate, ammonia, phosphate and turbidity.

According to the obtained results, no significant differences were detected between pH, temperature, dissolved oxygen, ammonia, phosphate, and turbidity in the two seasons (t-test, p>0.05), but a significant difference between levels of nitrate was found in these time periods (t-test, p<0.05).

The overall level of physicochemical parameters in that summer was higher compared to autumn. The increase in the levels of the investigated parameters in warm weather is probably due to increased temperature and decreased discharge. Rapid population growth in the area of Ardal and the demand for protein foods makes monitoring of the levels of physicochemical parameters of fish farms necessary. In addition to the mentioned factors, increasing the metabolic activities and density of fish in this season can increase the amount of physical and chemical parameters.

 Investigating the diet of fishes is important in order to investigate the ecological role and understand their position in the food web chains.

In this study, Feeding ecology of Aphanius vladykovi in Choghakhor wetland of Chaharmahal-O-Bakhtiary Province was evaluated seasonally. In this reason, the relative index of gastrointestinal (RLG), condition factor (CF) vacuity index (VI) and food items between male and female, two size classes in the hot and cold seasons were investigated.

Fish diet was primarily composed of crustaceans (Ostracoda, Ampipoda), mollusks (Gastropoda, Bivalvia), aquatic insect larvae (Ephemeroptera, Diptera) and detritus. There was no significant sex and size-related variation in food items. Diet composition was significantly different between hot and cold seasons (p < 0/05). Furthermore, the average of RLG index was 0.885±0.51that indicated the fish was carnivorous.

 In general, in this study, based on the average relative length of the intestine, A. vladykovi is introduced as a carnivorous fish. It is also at an average level in terms of nutrition. The change of season had an effect on the diet of this species, but the studied biological variables such as gender and size were not effective in determining the choice of food items.

In sustainable agriculture, cow manure is used for greater productivity, a rich source of E-Coli pathogenic bacteria. The objective of this research was to investigate the simultaneous effect of the fractionation size of cattle manure and irrigation water salinity on the retention of E-Coli bacteria in the depths of the sand column with a height of 10 cm under saturated flow. Four different particle fractions of cow manure (1-2, 0.5-1, 0.25-0.5, and smaller than 0.25 mm) were added to the surface of the sand column at the scale of 30 tons per hectare, then leaching was done with different salinities (0, 0.5, 2.5, 5, and 10 dS/m) up to 10 pore volumes, then samples were taken from the depths of 0, 3, 6, and 12 cm. The number of bacteria in each sample was determined by the live counting method. The results showed that the effect of all sources of change and their interaction effects on the retention of bacteria in the soil is significant at the level of 5%. Salinity had a negative effect on the retention of bacteria, and the highest and lowest values of the relative concentration of bacteria (the result of dividing the number of bacteria in each soil depth by the initial number of bacteria in the desired manure treatment) were in 0 dS/m and 10 dS/m salinity of leaching water, respectively. By decreasing the size of cow manure particles due to the increase in hydrophobicity and blocking of preferential pores, the retention of bacteria decreased in all investigated soil depths. The highest and lowest retention of bacteria in the soil were investigated in the largest cow manure particle size (1-2 mm) and the smallest cow manure particle size (less than 0.25 mm), respectively. In addition, the highest relative concentration of bacteria in the soil was seen in the depth of 0-3 cm, and no significant difference was seen in other soil depths.

Periphyton communities serve as vital component of stream ecosystems and they are the principal primary producers of the aquatic river ecosystems. Periphyton is useful as biological indicator of water pollution. Taxonomic diversity and abundance of periphyton depends on a range of factors like; temperature, disolved oxygen and nutrient availability. Yet, no study has been conducted on physicochemical parameters and periphyton composition of the headwater of the Beheshtabad River. Therefore, the present study aims to determine the influence of physicochemical parameters on periphyton composition of the Beheshtabad headwater stream ecosystem, which is prone to anthropogenic pressures. Sampling will be conducted monthly from seven stations along the reservoir. A monthly investigation was carrird out at seven sites over the period October 2015 to September 2016. Accordingly, density of periphyton communities was lowest in winter, with highest production was in summer. Considering the density of periphyton communities along with the dominance of the genus diatoms, the genus Naviculla showed the highest distribution, so that it was present at all stations and in all stages of sampling and constituted the dominant density.

Fish and other aquatic animals, directly and indirectly, can be contaminated with Listeria monocytogenes and consequently, fish and their products are considered a carrier for this bacterium. The present study investigated the contamination of farmed rainbow trout and common carp with this bacterium as well as the phylogenetics of the isolates. A total of 50 samples of farmed fish were obtained from local fish supply centers in Shahrekord City from July to September 2018. Based on the molecular experiments, 18 (36%) of the 50 studied samples were contaminated with L. monocytogenes as 26% and 10% of the isolates were found in trout and carp, respectively. From 18 isolates, 12 samples (66.66%) belonged to serotype 4b, one belonged to serotype 1/2a and the other 5 samples belonged to serotype 1/2b. According to the results of the present study and regarding the importance of the bacteria in terms of public health, continuous and accurate hygienic monitoring seems to be necessary.

Although many studies have been done on the effects of agricultural land abandonment, there is very little information about the impact of climate conditions on the restoration of abandoned agricultural lands. Human has changed most of rangelands to agricultural lands causing a decrease in carbon sequestration, depending on land management and tillage operations. One of the methods for rebuilding the land cover is the land abandonment, which results in enhanced organic carbon and decreased CO2 emission. Understanding the storage and dynamics of soil organic matter, especially in relation to changing land use, is fundamental to evaluate the role of soil as a carbon source or sink. After land use change from rangeland to cropland, agricultural practices decrease the C stored in soils and cause a net release of C into the atmosphere, which has strongly influenced the atmospheric CO2 levels and global C balance over the last centuries. For this purpose, this study aimed to assess the effect of interaction between agricultural land abandonment and climatic conditions on organic material reserves of primary soil particles.

The study area was located in semi-steppe rangelands of Sheida and Khargosh in about 60 km northwest of Shahrekord city, Chaharmahal-va-Bakhtiari province, central Iran. In this study, four treatments including rangeland, agricultural and cultivated land abandoned in the time series of 10-15 and 15-40 Year were selected. The sample plots were placed in the distance of transects, and the soil samples were collected from 0-30 cm depths with different rainfall conditions from two above-mentioned regions in three replications. For each region, the soil samples were transferred to the laboratory and then analyzed. The selected locations had same soil shape, topography, parent material, and slope. The soil samples of three plots were then combined and 24 samples were prepared. The distribution of carbon and nitrogen concentrations was determined at different soil particle components.

The results showed that the rangeland change to cultivated land did not have a significant effect on the amount of organic carbon, total nitrogen, and total carbon to total nitrogen ratio. However, the values of these indicators decreased significantly in the Sheida region. Under all land management, the amount of carbon and nitrogen of soil particles increased with decreasing the particle size from sand to clay. Hence, the abandoned agricultural land and rangelands did not significantly affect the amount of carbon and nitrogen concentration in sand, silt and clay particles. The amount of carbon, however, increased with the abandonment time and non-agronomic activity of carbon in sand and silt particles, although the carbon content of clay particle was not influenced. Agricultural practices may negatively or positively impact natural ecosystem depending on climatic condition and soil quality in unchanged lands. However, despite suitable climatic conditions (in terms of precipitation) and land cover in the rangelands over Sheida, the cultivation adversely influenced the soil quality and organic matter of the unchanged land. Although, the precipitation and soil quality were relatively lower in Khargosh region, the agricultural activities seem not to negatively affect the land quality. Moreover, rangelands change to cultivated lands did not have a significant effect on the amount of soil nitrogen in this region. The greatest nitrogen amount was measured in clay fractions of cultivated and abandoned lands for 40 years, and the minimum nitrogen content was detected in sand particles of lands abandoned for 15 years. The highest and lowest amount of nitrogen over all three fractions was, respectively, found for unchanged and abandoned lands in Sheida region. Therefore, the cultivated land depending on climate condition and management may considerably increase or decrease the organic carbon content in sand, silt and clay particles.

The results indicated that the agricultural land abandonment may differently affect the rangelands restoration measures such as the vegetation reclamation and soil carbon sequestration depending on climatic condition

Drought stress is one of the most important factors limiting plant growth all around the world. Plant Growth Promoting Rhizobacteria (PGPR) can significantly reduce drought stress effects on plants growth. This study was aimed to investigate the influence of PGPR (inoculation by Azospirillum lipoferum, Azotobacter chroococcum, Pseudomonas aeruginosa, and Bacillus cereus) on seed germination, seedling growth and photosynthetic pigments of Astragalus caragana under four levels of drought stress (0, -0.2, -0.4, -0.8 MPa) in laboratory conditions in Shahrekord University, Iran, 2017. Among the four PGPR treatments, A. chroococcum was eliminated because seeds failed to germinate and were identified as agent pathogenies. The results showed that inoculation by PGPR had a significant effect on all germination traits except shoot length. The effect of drought stress was significant on all traits expect mean germination time. The PGPR by drought stress interaction effect was significant on shoot length, embryonic leaf and seedling fresh weight, embryonic leaf and seedling dry weight, and root length. The highest and lowest seed germination indices and seedling length were related to first (control and -0.2 MPa) and second (-0.4, -0.8 MPa) levels of drought stress, respectively. It was concluded that P. aeruginosa was more effective in embryonic leaf fresh weight (0 and -0.2 MPa), embryonic leaf and seedling dry weight (total levels of drought stress); B. cereus (0 MPa) and A. lipoferum (0, -0.2, and -0.4 MPa) showed relatively better performance on root length and B. cereus (0 MPa), A. lipoferum (total levels of drought stress) and P. aeruginosa(-0.2 and -0.4 MPa; total levels of drought stress, respectively) improved growth of shoot and seedling fresh weight of the Astragalus caragana.

This study was aimed to investigate the effects of seed biopriming with plant-growth-promoting bacteria (PGPB) on some characteristics of germination and growth of Astragalus ovinus Boissunder drought stress. This study was conducted as a factorial experiment in a completely randomized design, with three replications. Percentage, rate of germination, mean germination time, vigor, chlorophyll a, b, carotenoids, fresh and dry weight of radicle, shoot, embryonic leave, seedling and radicle length, shoot and seedling were determined. Plant-growth-promoting rizobacteria at five levels including Pseudomonas aeruginosa (Schroeter) Migula, Azospirillum lipoferm (Beijerinck) Tarrand, Bacillus cereus Frankland, Azotobacter chroococcum Beijerinck and the control treatment were considered as the first factor. The second factor was applying drought stress at four levels of 0.0, -0.2, -0.4 and -0.8 MPa. Among the four biopriming treatments tested, A. lipoferm and A. chroococcum were eliminated, because the seeds were failed to germinate and identified as agent pathogenic. Results indicate that the use of these two PGPB increase the characteristics of germination (percentage, rate of germination, mean germination time and vigor) and growth (fresh and dry weight, length and photosynthetic pigments) of A. ovinus. It can be concluded that these two bacteria increase effectively the growth of A. ovinus under different levels of drought stress. In general, these two bacteria play a role in reduction of the negative effects of drought stress on A. ovinus.

Plants can be used as a suitable replacement for synthetic drugs such as antibiotics due to fewer side effects. Celery (Kelussia odoratissima) is a native plant of Iran along with anti-bacterial effects. This study aimed to compare the efficacy of anti-bacterial antibiotics with Ethanol extract of celery against four strains of Streptococcus iniae isolated from rainbow trout. In this regard, five treatments with different concentrations of 6.25, 12.5, 25, 50 and 100 µg/µl of extracts was developed. Then, Well Diffusion and Discs on Mueller Hinton methods were used to determine the antibacterial activity. Collected data were statistically analyzed using one-way ANOVA and the significant level of p< 0/05. The results showed that ethanol extract of celery in concentrations of 6.25 and 12.5 µg/µl had no effect on the studied bacteria. Also, there is no bacteria inhibition zone in bacteria concentration of 25µg/µl in 3, 4 bacterial isolates addition to 6/25 and 12/5 µg/µl. The most bacteria inhibition zone diameters were respectively recorded 19.33, 19.33, 18.67 and 15.33 mm that showed the difference between different concentrations (p<0.05).

In this study phylogenetic relationships among Garra sp. in the Karun, Karkheh and Dez basins were compared to Garra rufa, Garra mondica and Garra typhlops in the Tigris, Mond, Karkheh and Dez Basins. A total of 26 Garra spp. specimens were collected from different localities in the Karun, Karkheh, Dez, Mond, and Tigris basins. The specimens were compared using Cytochrome Oxidase Subunit I (COI) sequences. In existing reports it is indicated that the members of the genus Garra in Karun and Dez Basins lack scales in the area between pectoral fins and in thorathic region, which discriminate them from G. rufa. Based on such differences the fish in Karun-Dez basins are named as Garra gymnothorax. In this study it was tried to compare genetic differences among specimens collected from above noted basins. To sequence the 5’ end of COI gene forward and reverse primers were used. For the phylogenetic analyses Niebuhr-joining and Maximum likelihood methods of phylogeny reconstruction were used and for the analysis of the relationships among different haplotypes a haplotype network was drawn. To compare the differentiation levels among the studied species, K2P distances were calculated. In total 10 haplotypes were observed for the specimens sequenced in this study. On the phylogenetic tree reconstructed three sub-clades were resolved. The average genetic distance between G. rufa and G. gymnothorax was 5.87%. The maximum and minimum genetic distances were observed between G. gymnothorax and Garra tibanica and G.mondica and Garra elegans, respectively. The mean genetic distance among G. gymnothorax haplotypes was 0.33%. Based on the results of this study it can be indicated that Garra specimens in the Karun, Dez, and Karkheh Basins differ from G. rufa and belong to G. gymnothorax, which is concordant with the morphological differences reported in other studies. Opposed to G. rufa that has a vast distribution in Tigris, Euphrates and the Iranian Basins including Mond and Kor Rivers, G. gymnothorax is only distributed in Karun-Dez and Karkheh Basins. This limited geographic span of G. gymnothorax besides its closer affinity to G. typhlops may indicate that the species has been originated in the Karun-Dez and Karkheh Basins. In conclusion it should be noted that in this study only one gene was used and to make robust inferences it would be better to use other genes especially nuclear genes such as RAG7, Rhodopsin and the Next Generation sequencing approaches using more specimens from other localities in Karun, Karkheh, Dez, and other aquatic systems adjacent to these systems.

In the present study, the efficiency of the total flavonoids and aqueous extracts of M. communis L. tree leaves, as a recognized medicinal plant of Iran flora were assessed in vitro on the growth of the isolated fungi, Saprolegnia and Fusarrium using the agar disc and well diffusion methods in flat-bottom microplates in presence of the various extract concentrations. The isolated fungi were sampled from the fertilized eggs of rainbow trout fish incubation farms. The collected leaves from the natural habitats of Chaharmahal-o-Bakhtiary province at early-summer were extracted by maceration methods with water solvent as well by flavonoids extraction methods with methanol solvent. During the succeeding trials, the antifungal effects of the flavonoids extracts (by the well diffusion method) and the aqueous extract (by the well diffusion method) against isolated Saprolegnia were revealed by MFC (Minimum Fatal Concentration) values 50 and 100 mg/ml, respectively. The only effect of the methanolic and aqueous extracts of M. communis leaves revealed in vitro inhibiting effect on growth of isolated Fusarium by MIC values 25 and 12.5 mg/ml, in disc diffusion and well diffusion method, respectively. The antifungal obtained effects by the extracts had more effective aspects on isolated Saprolegnia in comparison to Fusarium. The results of the study indicate that M. communis could be considered as a potential candidate for designing effective antifungal suitable for treatment of the fish eggs fungal infections.

The bacteriostatic and bactericidal activity of the ethanol extract of Kelussia odoratissima and chicory, Cichorium intybus L., against Streptococcus iniae and Lactococcus garvieae isolated from rainbow trout was investigated. Antibacterial efficiency of the plants was examined using agar well diffusion method and minimum inhibitory concentration. The MIC of the ethanol extract of K. odoratissima for S. iniae and L. garvieae were found to be 100 and 50 mg/ml, respectively and the MIC of the ethanol extract of C. intybus L for S. iniae was 50 mg/ml. Chicory didn’t have any inhibitory effect on L. garvieae.

This study was performed in order to isolate lead (Pb)-tolerant plant growth promoting rhizobacteria in Pbcontaminated soils and to evaluate their potential for production of plant promoting substances. The isolated Pbtolerant rhizobacteria were identified as Rhodococcus sp., Bacillus stearothermophilus strain A, Corynebacterium sp., Bacillus pumilus, Mycobacterium sp., Bacillus stearothermophilus strain B, Bacillus licheniformis and Bacillus sp. The results showed that all isolates were able to tolerate high concentrations of Pb. The minimum inhibitory concentration (MIC) of these bacteria was in the range of 1100 1720 mg l-1 (3.3-5.19 mM). In addition, all isolates produced IAA (ranging from 3.53 to 43.64 mg l-1) and siderophore (ranging from 57.74 to 86.24%). However, only two isolates (i.e., Bacillus licheniformis and Mycobacterium sp.) had the ability to produce bacterial enzyme ACC-deaminase. Inoculation of medium containing poorly soluble PbCO3 with bacterial strain Corynebacterium sp. significantly increased the available concentration of Pb.

To study of microbial and some of heavy metal in forage corn and soil، field experiment was conducted in wastewater treatment plant in Shahr-e- kord in summer، 2011. Plots were arranged in a randomized complete block design in 3 replications and 2 treatments، well water with fertilizer (W1) and effluent (W2). Results showed that total number of positive lactose bacteria، total and fecal coliforms in depth of 0-5 cm was 42% more than depth of 5-15 cm. In old leaves، total and fecal coliform was 88 and 40 MPN /100 ml، respectively. Also، for new leaves، it was 38 and 2 MPN/ 100 ml، respectively. During the time، number of indicator bacteria in soil was decreased (about 35%). Heavy metal contents in W2 was more than W1 in stem and leaf but there was no significant difference between them. In soil and plant heavy metal contents were in acceptable level.

In arid and semi-arid regions، wastewater reuse has become an important element in agriculture. However، irrigation with this resource can be either beneficial or harmful، depending on the wastewater characteristics. The aim of this research was to investigate the soil bacterial and crops quality irrigated with treated wastewater. This research was conducted on a maize field near the wastewater treatment plant in Shahr-e-kord in summer،2011. Plots were arranged in a randomized complete block design in 3 replications and 2 treatments، well water (W1) with fertilizer and effluent (W2). At the end of growth season، soil samples were collected from depth of 0-5 and 5-15 cm and plant samples consisting of old and new leaves and seeds were collected for bacteriological analysis. According to bacteriological analysis، total number of positive lactose bacteria، total and fecal coliforms in depth of 0-5 cm was 42% more than depth of 5-15 cm. In the case of old leaves، total number of coliform and fecal coliform was 88 and 40 MPN/100 mL respectively. Moreover، for new leaves، it was 38 and 2 MPN/100 ml respectively. According the results، number of indicator bacteria in soil is decreased (about 35%) by passing time.