نشریه یافته های نوین در علوم زیستی
سال چهارم شماره 3 (پیاپی 13، پاییز 1396)

Thirty eight ecotypes of watermelon were collected from different parts of Iran. After the preparation of the field, these eotypes were cultivated in a completely randomized block design with three replications. In order to invest-igate genetic diversity, genomic DNA samples were extracted from leaves and Polymerase chain reactions were optimized using 14 SRAP primer pairs. One hundred thirty six polymorphic bands were detected, of which the EM10-Me4 was the most abundant primer pair with 19 bands and EM16-Me4 and EM16-Me14 were the least primer pairs with 7 bands. PIC index varied from 0.20 to 0.32 and genetic diversity was 0.17 to 0.28 on the basis of Nei index. Fisher's Linear Detection Analysis showed that the UPGMA method and the grouping accuracy of about 90% are more appropriate than other cluster analysis methods. Cluster analysis, using Jakard method, was performed and the ecotypes studied were classified into five distinct groups. Based on the PCA, the first and second components included 92.5% of the variation, which represents the proper distribution of the markers on the whole genome.

Several therapeutic effects have been reported for Peganum harmala and Piper longum. These plants contain flavonoids that probably can affect reproductive endocrine system and reduce fertility. In this study, the impacts of hydroalcoholic extracts of Peganum harmala and Piper longum on pituitary-gonadal axis were investigated. Male mice were divided into one control group and three experimental groups. The first experimental group received the extract of Peganum harmala (200 mg/lit), while the second experimental group received the extract of Piper longum (200 mg/lit) and the third experimental group received the combination of both extracts (200 mg/lit) for 30 days. After the treatment, spermatogonia, spermatocytes and spermatids were counted and serum levels of testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were measured. Data were analyzed by SPSS software. Levels of testosterone, FSH and LH showed a significant decrease in the first and third experimental groups in comparison with the control group. Moreover, the number of spermatogonia, spermatocyte and spermatid decreased in these groups. The results of the present study demonstrated that hydroalcoholic extract of Peganum harmala and Piper longum can decrease the pituitary gonadal axis function and spermatogenesis in male NMRI mice.

Of different types of bio-compatible nanoparticles, iron oxide nanoparticle has attracted attention for its applications especially in medicine and magnetic resonance imaging (MRI). We decided to study histological changes in testis and spermatogenesis in mature male mice that are affected by ironoxide nanoparticles (Fe2O3) during fetal period. In this study, the mice were divided into three experimental and two control and sham groups. Iron oxide at do-ses of 10, 30, 50 mg/kg were injected into pregnant mice during 10th, 12th and 14th days of the critical period of fetus testis development. After the maturation of the mice which were born, slices with the thickness of 0.06 µm were prep-ared from adult male testis and epididymis, stained with hematoxylin and eosin. The cells were counted, then the obta-ined data was analyzed with one-way ANONA and Tukey testes. The results showed that the number of epididymis sp-erms at the doses of 10 and 30 mg/kg, testis weight at the dose of 30 mg/kg, primary spermatocytes at the dose 10mg/kg had increased, while the testis diameter in all the three experimental groups and the volume of the testis at the dose of 50 mg/kg had decreased. Disorganization and vacuolization were observed at high doses. Passing through the cell me-mbrane, and considering its oxidation and reduction potentials, it was observed that Iron oxide nanoparticle acts as anti-oxidant at low doses and shows toxicity at high doses. The fact obtained in the paper reflects the dual potential of the ir-on oxide nanoparticle.

Water stress is one of the most important factors limiting the growth and yield of plants in many parts of the world. In order to evaluate the effects of water stress on some morphological, physiological and antioxidant enzyme activity traits of lentil, four lentil cultivars (i.e. Gachsaran, Kimia, Ziba and Robat) in four water deficit treatments including 25%, 50%, 75% and 100% of the field capacity (control) were studied in a factorial experiment, based on a completely randomized design with three replications. Water stress at 25 and 50% field capacity significantly decreased morpho-physiological traits and significantly increased antioxidant enzyme activity, proline and protein contents of all genotypes in comparison with the control group. Gachsaran and Robat cultivars were superior in most traits in comparison with the Kimia and Ziba cultivars. Under severe stress, the amounts of proline and protein contents, CAT and SOD enzyme activity were significantly higher in Robat and Gachsaran cultivars than those of the Kimiya and Ziba cultivars. Results showed that Robat and Gachsaran cultivars were probably affected less by water stress due to more stress tolerance using various mechanisms such as more antioxidant enzyme activity, increased proline, proteins and photosynthetic pigments contents. Studied traits were introduced as suitable markers for identification of drought tolerant genotypes. Accordingly, Robat and Gachsaran cultivars were introduced as tolerant cultivars for cultivation under rainfed conditions.

To investigate the Artemisia vegetation in Isfahan Province, two rangelands of Khorous Galu in the southwest and Ashan in the west of Isfahan were selected. These rangelands are mountainous with semiarid climate. In Khorous galu, 68 species belonging to 50 genera and 24 families were identified. Life forms included hemicryptophytes (39%), therophytes (27.5%), chamaephytes (19%), geophytes (13%) and phanerophytes (2%). Chrotypes existent in Khorous Galu were composed of 56 Irano-Turanian species, 3 Euro-Siberian-Irano-Turanian species, 4 Euro-Siberian-Irano-Turanian-Mediterranean species, 2 Irano-Turanian-Mediterranean species, 1 Irano-Turanian-Saharo-Sindian species and 1 cosmopolitan species. In Ashan area, 88 species belonging to 67 genera and 29 families were identified. Hemicryptophytes (39%), therophytes (28%), geophytes (17%), chamaephytes (15%) and phanerophytes (1%) were the life form composition of the region flora. 73 Irano-Turanian species, 7 Euro-Siberian-Irano-Turanian species, 4 Irano-Turanian-Mediterranean species, 1 Irano-Turanian-Mediterranean-Euro-Siberian species and 1 cosmopolitan species were identified. 2 species were recorded from Isfahan Province for the first time. With regard to the similarity of flora in both regions, that is due to effective similar environmental factors, a uniform management plan for A. aucheri rangelands in Isfahan Province could be selected.

In this study, fungal strains with crude oil biodegradation activity were screened from Shazand oil refinery (Arak). Twelve fungal strains were isolated in PDA medium. TPH assay in the presence of 1% of crude oil showed that the ADH-02 was the most capable strain of oil degradation with an efficiency of 75%. FTIR analysis was revealed that 91% of aliphatic hydrocarbons were degraded by ADH-02. This strain proved to belong to Gliomastix genius with a similarity of 99%. Polycyclic aromatic hydrocarbons degradation analysis with HPLC demonstrated that this strain is capable of removing 67% of anthracene in 14 days. The results showed that Gliomastix sp. was a potent fungal strain in bioremediation of crude oil and polycyclic aromatic hydrocarbon.

Three types of chitin as α (exoskeleton of crustaceans), β (cuttlebone of cephalopods) and γ (some fungal cell wall) exist in nature. Chitosan is the most important derivative of chitin, which has various biological activities. In this study, α, β and γ-chitosans were extracted from Portunus segnis exoskeleton, Sepia pharonis cuttlebone and Aspergillus niger cell wall, respectively. Samples of crab and sepia from Bandar Abbas coastal waters were gathered in the summer of 2014 and samples of Aspergillus niger (PTCC 5223) were obtained from the Iranian Research Organization for Science and Technology (IROST). The amount of chitosan extracted from the Crab was significantly higher than other samples. Antimicrobial properties of these three types of chitosan were explored against 9 bacterial and 2 fungal strains using disc diffusion method. On average α chitosan and γ chitosan revealed to have highest and lowest antimicrobial activities, respectively. Antibacterial properties of chitosan extracts were more than their antifungal properties. Gram negative bacteria as well as gram positive bacteria were sensitive to three types of chitosan. According to observed results, all three types of chitosans have good antimicrobial activities, and further investigations are suggested.

Thyme plants are considered to be one of the most widely consumed herbs well-known for their essential oils and secondary metabolites. In order to evaluate the effects of temperature on antioxidant activity, total phenolics, agronomic traits and essential oil of two thyme species (i.e. Thymus vulgaris and Thymus caramanicus), a greenhouse experiment was conducted in 2015 with split plot in a completely randomized design with three replications. The results of this experiment showed significant differences between the two species and different temperatures in terms of the tr-aits measured. The essential oil percentage, antioxidant activity, total phenolics and plant height of Thymus carama-nicus proved to be more than those in Thymus vulgaris. The comparison of mean interaction effect for essential oil pe-rcentage showed that the value of this trait in Thymus caramanicus specimens treated with a temperature of 30°C was more than other treatments. The IC50 rates of Thymus vulgaris and Thymus caramanicus ranged from 24.37 to 54.43 µg/ml in different conditions and total phenolics ranged from 36.63 to 89.37 mg GAEg-1. In addition, the highest anti-oxidant activity, essential oil percentage and phenolic compounds were observed at a temperature of 30°C for both species.

Hyrcanian forests in northern Iran have important tree and shrub elements of Euro-Siberian and rare forest communities, among them beech community widely covers the mountainous forests from Western to Eastern (Gorgan) Hyrcanian region. In order to identify the floristic characteristics and affecting factors on the species richness in pure beech stands in Eastern Guilan, using systematic-random method 54 plots were recorded. A total of 111 plant species belonging to 84 genera and 44 families were identified, with Orchidaceae having 9 species and genus Carex with 6 species being the largest family and genus, respectively. The highest frequency inter-species is Galium odoratum, an understory herb species forming communities in different areas of beech forests in Hyrcanian region. Since the studied region is forest and mountainous, hemicryptophytes and geophytes are the most life forms, respectively in these areas and Euro-Siberian elements (with 30.6 %) form the highest frequency from a chorological point of view. Also, the size of the microrelief and percentage of tree cover create different ecological conditions in plots such as moisture retention and change in the amount of incoming light into the plots, which are the most influential factors on species richness of these areas.

Fish oil in the diet of fish is constantly at the risk of oxidation. In this study, the effects of feeding sturgeon hybrid (Huso huso ♂ ×Acipenser ruthenus ♀) with different levels of oxidized fish oil (OFO) on thyroid hormones were investigated. Three experimental diets were made by replacing 0 (control), 50 and 100% OFO were made. Ninety hybrid sturgeon, with the initial weights of 212.6 ± 07g were distributed in 9 fiberglass tanks (2 m3) randomly after 2 weeks of adaptation with experimental conditions. Feeding was performed three times daily (08:00, 14:00 and 20:00) for 6 weeks for satisfaction. At the end of the period, blood samples were taken and their serum was separated. Serum thyroxine and triiodotyronine were measured by radioimmunoassay in blood samples. Serum thyroxine, triiodotyronine and thyroxine/triiodotyronine level showed no significant change related to dietary OFO. Our findings showed that dietary-oxidized oil had no effect on blood thyroid hormones levels.