Solvent extraction and taguchi method were used to optimize conditions for the antioxidant activity of Azolla fern extracts. The independent processing variables were ethanol concentration, extraction time and solid to solvent ratio. Ethanol concentration and solvent to solid ratio significantly affected antioxidant activity measured by the total phenol content (p<0.05). whereas the extraction time did not significantly affect the activity (p>0.05). Antioxidant activity of the extracts, determined by the total phenolic content, varied from 5.77 to 16.42 mg acid gallic equivalents/g of dry sample. DPPH scavenging activity percentage ranged from %20.51 to %93.71. Ethanol concentration of %50 and sample to solvent ratio of 1 to 15 were optimal for the highest antioxidant activities measured by the TPC assay and the DPPH method. The optimal extraction time was 48h. The result show that Azolla fern is suitable for antioxidant extraction.

This study was conducted to evaluate the amount of moisture, protein, lipid and ash of wild and farmed Azolla (Azolla filiculoides) for nutritional application of livestock and human. Fatty acid composition of Azolla, a key component for making decision about the nutritional value, of both Wild and farmed types was also compared. The Azolla samples were collected from Pirbazar region, Anzali Wetland and cultured in aquarium containing appropriate medium to consider the process of growth and propagation. The fatty acid composition of wild and farmed samples was determined according to the Folch method for GC Analysis after the lipid esterification. No significant difference (p>0.05) was observed between wild and farmed Azolla in the amount of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs). However, palmitic acid, margaric acid, oleic acid, cis-linoleic acid, and a-linolenic acid of wild Azolla was significantly higher than farmed type (p<0.05). In contrast, lignoceric acid amount of farmed Azolla was significantly (p<0.05) higher than wild Azolla. Given the appropriate amount of lipid, both types of wild and farmed Azolla could be used as feed for livestock, poultry and even human, although wild Azolla had more lipid content compared to the farmed type. Furthermore, speed of propagation followed by the short doubling time of Azolla in vitro provides the ability for adequate amounts of oil extraction from this fern.

Microcosm experiments were conducted under controlled environmental conditions in order to estimate growth response and phytoremediation ability of A. japonica and A. pinnata. Plants were exposed to solutions of different Cu-concentrations [Cu] (0, 1, 2, 5 and 7 mg L-1) and Zn-concentrations [Zn] (0, 0. 5, 1, 2 and 4 mg L-1) under different incubation periods (0, 3, 6, and 12 days) along with control treatments. Lower metal concentrations [< 2 mg L-1 (Cu) and < 1 mg L-1 (Zn)] enhanced plant growth; however, growth was significantly inhibited at higher concentrations during Longer Incubation Periods (LIPs). Azolla species showed substantial metal removal capacity (on an average, Removal efficiency> 80% for Cu and > 60% for Zn during LIPs). The higher the metal concentrations with LIPs, the higher the metal removal amounts. Plant`s exposure to high (Cu) and (Zn) during LIPs showed changes in color and detachment of the roots that might result in plant death due to phytotoxicity effect. Highly significant relationships (r= 0. 91** & 0. 82** for Cu and r= 0. 93** & 0. 92** for Zn in case of A. pinnata and A. japonica, respectively) between metal removal amounts and metal concentrations in biomass indicated that phytoaccumulation was the possible mechanism for phytoremediation because the metals removed from solutions were actually accumulated into the plant`s biomass. The high value of bioconcentration factor indicated that Azolla species were hyperaccumulators, and can be deployed effectively for phytofiltartion of Cu and Zn.

In order to investigate the effect of different phosphorus and radiation treatments on Azolla growth and water use efficiency (WUE), an experiment was carried out at the Agricultural Research Greenhouse of Razi University, Kermanshah, Iran. The experiment was a factorial with three factors based on a completely randomized design with three replications. The first factor was cultivation dates (4 May and 4 June), the second was radiation levels (0, 50 and 100% of full sunlight) and the third was phosphorus treatments including control (without fertilizer), chemical fertilizer and chicken manure. Results indicated that the highest dry matter produced and water use efficiency occurred at the 100% level of full sunlight. At the higher radiation levels (50 and 100% of full sunlight) chicken manure performed better as compared with the other phosphorus treatments. Moreover, at the 100% of full sunlight, there was no significant difference between the two cultivation dates in terms of WUE.

Waterferns have caused many problems in aquatic ecosystems and rice fields of northern regions during recent decades. Despite the fact that Azolla spp. are known as one of the most important invasive species worldwide, with management and applying biological control agents in natural habitats they can be used as beneficial species. For Azolla management, it is very important to have enough knowledge about the reproduction, substantial conditions for invasion and biological control agents of the plant in the area. . In northern regions favorable environmental conditions such as high humidity, suitable temperature, absence of specific natural enemies and etc, caused Azolla spp. expansion and invasion. In recent years, it has been demonstrated that some of the native and migratory species such as Cataclysta lemnata, Nomophila noctuella, Diasemiopsis ramburialis and Rhopalosiphum nymphaeae feed on Azolla spp. in the area and have high dispersal. Recently, exotic weevil, Stenopelmus rufinasus, has been recorded in the area as well. Studies indicated that C. lemnata and S. rufinasus as biological control agents and other species as biotic resistance factors can be used for Azolla spp. management in northern regions. According to these findings and existing knowledge we have enough resources to control Azolla, and by providing of the necessary facilities it can be controlled in northern regions of Iran.

Background and objectives: Considering the two environmental problems that have plagued the northern provinces of the country in the recent years, they include a high volume of waste after harvesting rice and the excessive growth of Azolla fern and the waste after collecting it from the surface waters. This research was carried out in the production of biological conditioners from these wastes and their effect on improving and strengthening the soil edge of the Anzali lagoon. Therefore, biochars have been prepared from Azolla fern and rice husk and Azolla compost was also prepared as biologicalal conditioners. The effect of these three conditioners on the chemical characteristics of the soil at the edge of the lagoon were investigated. This is the first time that two environmental problems (Azolla fern and rice wastes) have been used as an opportunity to improve and strengthen the soils of the region.Materials and methods: For this research, at first, soil samples were taken from the edge of the lagoon. After producing the remedial treatments (rice husk biochar, Azolla biochar and Azolla compost), they were mixed with the soil sampled from the edge of the lagoon at three levels of 0 (control), 2 and 4% and the treatment was carried out. The samples were incubated in closed incubation containers of 1 kg for a period of six months and the treatments were prepared in 3 repetitions. At the end of the incubation period, the chemical characteristics of the soil including: acidity, electrical conductivity, cation exchange capacity, percentage of organic matter, percentage of organic carbon, and amount of: calcium, magnesium, sodium, potassium, phosphorus, and nitrogen, were measured. This research was conducted as a factorial experiment and in the form of a completely randomized design.Results: The results of the analysis of variance showed that the effect of the type of biochar and its level, as well as their mutual effect on all the examined characteristics, was significant at the 1% level compared to the control sample. Among the remedial treatments, biochar Azolla treatment recorded the best result compared to other remedial treatments with the highest increasing performance on the available phosphorus, nitrogen, sodium, magnesium, organic matter percentage and pH. After that, Azolla compost remedial treatment with high increase performance on available potassium, electrical conductivity and cation exchange capacity recorded a better result. The best performance of the modifying treatments was mainly observed at the level of 4 mass percent of the treatment mixed with the soil. By increasing the level of the modifier compound with soil, a significant increase was observed at the level of 5% in all the measured characteristics and elements.Conclusion: The results of the analysis of variance of the effect of time, biochar type, level of polluted water and level of biochar on all the investigated parameters showed a significant effect at the 1% level compared to the control sample. According to the results of this research, by using biological conditioner such as biochar and compost, it can be seen reducing the amount of agricultural waste and the problems caused by them (depositing, burying and burning them), we can use these problems as an opportunity. Used to modify, strengthen and improve the chemical properties of soils.Keywords: biochar, Azolla compost, rice husk biochar

Phytoremediation is a sustainable and inexpensive technology and has become popular as an alternative solution to traditional wastewater treatment methods. The aim of this study was to use fish farm effluent as a culture medium for the Azolla and also to improve the effluent. For this purpose, the initial amount of 60 g of Azolla was dvided in two treatments with three replications, including Azolla in the wastewater of Beluga sturgeon farm (SW) and Azolla in the water of Anzali wetland (AL) which were grown in-vitro for 30 days. Sampling of water was performed to evaluate some water quality parameters at 10, 20 and 30 days. At the end of the experiment, the plant growth performance, fatty acid profile, and approximate composition were measured. The results showed that maximum amount of biomass (295. 22 g) and plant width (9. 64 mm) were observed in SW treatment (P<0. 05). Also, the results of fatty acid composition showed that saturated fatty acids in SW treatment had a significant increase compared to AL treatment. However, unsaturated fatty acids in SW treatment showed a significant decrease compared to AL (P<0. 05). In addition, a significant downward trend in the water quality parameters (phosphate, nitrate, and nitrite) was observed in SW treatment on day 30. The highest and lowest contents of fat and moisture were observed in SW treatment (P<0. 05). Therefore, the production of Azolla in Beluga farm effluent can be an effective and cost-effective method due to the rapid growth rate, high ability to absorb the amount of phosphorus and nitrogen in water, as well high nutritional values (protein and lipid contents) and high diversity of fatty acids.