مجله زیست شناسی ایران
سال بیست و یکم شماره 4 (زمستان 1387)

The purpose of this study was to investigate plant population ecology of Ribes khorasanicum, an endemic species to north of Khorasan, in Hezar-Masjed mountains. The soil analyses, anatomical studies, life form, phenology, regeneration strategies, distribution in Khorasan Province and responses to environmental conditions of the plant were considered. Some plant characteristics such as cover percentage, abundance, height, number of flowers and buds, dry matter percentage of each organ and age of individuals were recorded in two patches of its distribution. The results showed that R. khorasanicum is a woody deciduous shrub with phanerophyte life form (Micro-phanerophyte with 2-8 meter tall) which contains rhizome and mainly regenerates by vegetative method. It grows in natural and non saline soils with a pH ranging from 7.3 to 7.5 dominated by lomy ones with good drainage and a high amount of N and K and low amount of P. The plant is scattered on north aspects of Hezar- Masjed mountains up to the altitude of 2400 m.a.s.l. The leaves get sunburn and fall by the high temperature and sunlight intensity. Percentage of dry weight of organs is high in aerial stems and low in the roots. Phenological studies of the species revealed that vegetative growth, appearance of leaves and flowers as well as unripe and ripe fruits were in early to late of April, early of May (for 20 days), and early of June to late of July, respectively. The dormancy of plant is in the autumn and winter. On the whole, plant population ecology of R. khorasanicum showed that it is a valuable plant in some aspects such as medicinal properties, utility of fruits, palatability to grazers, soil protection and ornamental habits. According to WCMC, the species was assigned to Vulnerable (VU) category.

Land trials were conducted in Hezarmasjed mountains to study the effects of nurse plants (planting under nurse plant or planting in open areas) and their planting geographical position (north, south, east, west) on survival and height growth of Juniperus excelsa seedlings. The layout was randomized systematic design. With three replicates and 30 seedlings in every replicate. In total 720 seedlings was planted. Seedling survival and seedling height were measured twice a year (middle spring and middle autumn). Results showed that seedlings survival under nurse plants and in north directions were higher than others. Seedling height in open area and north directions were relatively higher rather than other directions. In conclusion, seedlings planted under nurse species such as Cotoneaster sp, Rosa sp. have more growth survival and establishment in primary years than seedlings planted in open areas.

Cadmium is a non-essential element that negatively affects plant growth and its development. In this study, the effect of an arbuscular mycorrhizal (AM) fungus Glomus intraradices on some growth and physiological traits such as fresh and dry weight of root and shoot, photosynthetic pigments, total sugars, total protein content, lipid peroxidation and oxidative stress in wheat (Triticum aestivum L. cv. Azar2) plants under the toxic levels of cadmium was investigated. The experiment was performed by using two treatments (mycorrhizal and non-mycorrhizal) and four cadmium concentrations (0, 250, 750 and 2500 µM CdCl2). Plants received 40 mL nutrient solution (with half P content) three times a week and also 40 mL test solution (contained cadmium) three times a week, alternatively. Plants were grown in a growth chamber with temperatures ranging from 23 to 27ºC and a 14/10 light/dark period. Leaves and roots from 60-day-old plants were taken and used for investigation. Arbuscular mycorrhizal fungi had a significant influence on root and shoot fresh and dry weights, where the presence of AM fungus caused a decrease in the negative effect of Cd toxicity. Root length decreased due to an increase in Cd concentration, but there was no corresponding effect on the shoot length. Colonized plants showed less negative effect of Cd on their root length than non-AM plants. Determination of chlorophyll a and b content showed decreased chlorophyll content in both AM and non-AM plants by increasing Cd concentration, but this decrease in the mycorrhizal plants was lower than in non-mycorrhizal plants. By increasing in metal concentration, the content of total sugars and total proteins increased in both shoots and roots of AM plants. The amount of malondealdehyde (MDA) increased in roots and shoots of mycorrhizal and non-mycorrhizal plants under Cd toxicity, indicating lipid peroxidation. Activity of detoxifying enzymes, guaiacol peroxidase (GUPX) and ascorbate peroxidase (APX) in AM and non-AM plants increased but the increase of these activities in mycorrhizal plants was higher than non-mycorrhizal ones. Root length colonization was measured by gridline intersect method. Mycorrhizal colonization decreased due to the Cd exposure significantly. According to these results, it is suggested that this fungus (G. intraradices) can help wheat plants to tolerate Cd toxicity.

Planktonic algal samples were taken from Zayandeh Rood Dam lake of four stations, and from surface, 0.5, 3 m depths. Triplicate samples were gatherd by Nansen sampler in each sampling occasions. Additional samples were taken from the surface with plankton net. Samples fixed with 4% formaldehyde and were centrifugated to final volume 300 ml. In this study 112 species belonging to 53 genera were identified. Cyclotella meneghiniana kutz, a centric diatom, was dominant species in the period of study. Physico- chemical parameters such as temperature, salinity, pH, EC, DO, BOD, COD, NO3, PO4, SO4 were also determined. The present study revealed that Zayandeh Rood Dam lake is an oligo- mesotrophic water, and some phytoplanktons can be use as indicators for evaluating of water quality.

Salinity and water stress are the major factors limiting plant growth and productivity. Against these stresses, plants adapt themselves by different mechanisms including change in morphological and developmental pattern as well as physiological and biochemical processes. Ultraviolet radiation has important morphological and physiological effects on plants. In this research the effects of UV-C and salinity stress on some biochemical parameters in two varieties of wheat (Dez and Darab) were investigated. seeds were exposed to UV 10 minutes every day up to 3days. Then seeds were sown and when seedlings were 21days old were treated with NaCl (5, 10 and 15 ds/m). two weak after salinity treatment, a, b and total chlorophyll content and carotenoid, anthocyanin and flavonoid content and electrolyte leakage were measured. Results showed that salinity stress had significant effects on a,b and total chlorophyll, carotenoid, anthocyanin and flavonoid contents and electrolyte leakage. Interaction of UV and salinity stress had significant effects on chlorophyll b, carotenoid, anthocyanin and flavonoids which had absorption at 300 and 330nm. Our results showed that UV pretreatment could only mitigate these reduction when salinity is not high (10 ds/m). But when salinity was high pretreatment with UV had no effects.

Little information is available regarding genetic variation in Triticum boeoticum, as a common wild wheat relative in Iran. In order to study floristic, phytochemical and molecular classification of this species, an analysis was conducted on populations of the T. boeoticum collected from different regions of Iran. All three markers nearly showed a high variability in T. boeoticum populations. In another word, distinguished grouping of populations in floristic method was confirmed by both phytochemical and molecular methods. The results from our study indicate that floristic classification in some way is still useful, efficient, and economic tools for characterizing the amount and distribution of genetic variation in natural populations.

Salicylic acid (SA) or orthohydroxybenzoic acid and related compounds which are be-long to this group are plant phenolics that play a major role in regulation of many phys-iological processes e. g. growth, development, ion absorption and seed germination. The effect of SA on germination, shoot and root fresh and dry weights, shoot and root length, leaf area, sugar and protein content were investigated of pepper (Capsicum an-nuum L.) under UV-A, UV-B and UV-C radiation. The plants were grown in vermicu-lite. Before applying the treatments, plants were subjected to a based nutrient solution (Long Ashton) for 5 weeks. After 5 week, leaves of plants were sprayed with 1. 5 mM salicylic acid and plants were treated under treatment UV-A، UV-B and UV-C for 2 week. Results showed that the percentage of seed germination significantly increased under UV-A and UV-C with salicylic acid. Rate of germination significantly decreased under UV-C and salicylic acid. In addition decreased leaf area in the UV-applied group were restored by SA application. Shoot and root fresh and dry weights significantly in-creased under UV-A, UV-B and UV-C with SA in comparison with only UV-A, UV-B and UV-C. UV-A, UV-B and UV-C stress and salicylic acid treatment increased stem length but only UV-B and UV-C stress and salicylic acid treatment increased root length. Therefore we concluded that the application of salicylic acid can protect plants against UV-radiation and in terms of improving the measured plant growth criteria. Sugar content significantly increased under UV-A, UV-B and UV-C when salicylic acid were applied. Protein content significantly increased under UV-A when salicylic acid were applied.

In order to study on effects of some extenders to prolong sperm motility in Huso huso, was used of five treatments. Sperm was added to the extender medium and diluted at different ratios of: one part sperm to 0 part extender, 1:1, 1:2, 1:3 and 1:4 respectively and three replicates run for each treatment. Sperm samples were extracted of five fish in Feb 2004, the samples were transferred in central laboratory of Agriculture Science and Natural Resources, Gorgan University. In order to prolong duration of sperm motility was used composition of extender solution: 1.0 g sodium chloride, 0.2g potassium chloride, 0.5 g sodium bicarbonate, 0.05 g calcium chloride (anhydrous), 0.05g magnesium sulfate, 0.15 g sodium phosphate dibasic (anhydrous) and 9 g glucose to 1 L of distilled water. for estimating the duration of sperm motility, the diluted semen was transferred to microscope slide. In this study, significant difference is observed in the motility duration between different treatments 2 days after adding extender solution. In treatment 2; duration of sperm motility was higher than treatment 1 and in treatment 3 and 4 was significantly lower than treatment 1. 6 days after increasing extender solution, duration of sperm motility in treatment 2 showed significant difference in the ratio of treatment 1 and in the others treatments were not significant difference, (P>0.05).Results finally indicated that use the extender solution in 1:1 dilution ration prolonged the spermatozoa viability in short-term storage of Huso huso semen and this ration significantly prolonged the sperm motility for up to 21-28 d at 4ºC.

Drug of abuse causes tolerance and dependency in brain and diversity of behavioral and cognitive deficiency. The effect of morphine dependency on learning and spatial memory is controversial. So in this study role of NO in CA3 region of hippocampus on learning and spatial memory in normal and morphine dependent rats was investigated. After anaesthetization of male rats, cannulae is implanted bilaterally in CA3 region of hippocampus via the stereotaxic instrument. After recovery period (7 days), animals divided in the normal and morphine dependent groups. Then normal group of animals divided in 4 subgroups that received 1μl saline (Sham), L-Arginine (63 or 3μg/rat), L-Name (71μg/rat), centrally. Morphine dependent group divided in 3 subgroups that received 1μl saline (Sham), L-Arginine (63 μg/rat), L-Name (71μg/rat), centrally. Two groups were control and morphine dependent that only cannulated. Morphine dependency was induced by subcutaneous injection of morphine (10mg/kg first day and 20mg/kg for four days). Last dose of morphine (20mg/kg) was injected daily to maintain morphine dependency during the test period (5 days) that animals were trained in morris water maze to evaluate learning and spatial memory. Results showed that in normal rats L-Name(NOs inhibitor) decreased learning and spatial memory and 3μg/rat of L-Arginine(precursor of NO) improved learning and spatial memory. Morphine dependency decreased spatial memory but it did not affect learning. In morphine dependent animals both L-Name and L-Arginine decreased learning but did not affect spatial memory. So morphine dependency could prevent the improving effect of NO on learning and spatial memory in CA3 of hippocampus.

Bream (Abramis brama orientalis) is one of the species of Cyprinidae that lives in Caspian Sea and its watershed. During the recent decades by several reasons such as over fishing, pollution increase, destroying of spawing regions, the fish stock decreased in south coast of Iran, Caspian Sea. Because of that, during the previous years, Iran Fishing Organization decided to recover the fish stock by the usage of artificial reproduction of a broodstocks of Bream population in Iranian Caspian Sea coast. So it has been decided that by entering Bream from Azerbaijan Republic coast an increase can occur in population diversity of that fish, thereby from each 3 mentioned regions 30 were hunted and carried to the genetic laboratory. After extracting DNA by Phenol-chloroform method for genetic-molecular research PCR-RFLP technique was use on a mitochondrion genome piece by the length of 3500 contains tRNA-glu, tRNA-leu, ND 5/6 and Cyt b. Between 17 used enzyme, 4 enzyme DraI, BCLI, Hae III and BanII showed diversity which generally 6 haploids was recognized. The most nucleotide diversity 0.58% by presence of all haploids was observed in Azerbaijan Republic coast samples while Anzali wetland and Iranian Caspian Sea coast, Bream had no diversity. Also, statistical analysis by the usage of Monte Carlo test by 10000 repetition showed a significant differences between Azerbaijan Republic coast fishes (p<0.0001) but there was no significant differences between two regions (p>0.5).

White muscardine is one of the current diseases at the sericulture industry. This disease is not remediable. Therefore selection of the resistant varieties is one of the best strategies for decrease of damages among farmers. Furthermore recognition of resistant varieties is essential for transition of resistance genes in the breeding of silkworm varieties. This experiment was conducted to determine the performance of commercial pure lines of silkworm Bombyx mori under stress of white muscardine fungus. In this experiment that was accomplished during summer and autumn seasons, 9 commercial pure lines by means of a completely randomized design with 5 replications for each treatment were used. The economical traits including number of live larvae and pupae, percentage of vitality of pupae, number of produced cocoons, number and percentage of the best, middle, low and double cocoons, the best cocoons yield, single weight cocoon, cocoon shell weight, percentage of cocoon shell and larval duration were recorded and analyzed. From the obtained results, lines of Y-2 and 103 showed the highest vitality of larvae. Furthermore these mentioned lines showed the highest number of produced and the best cocoons. In this manner lines of 109, 107, 31 and 103 showed the highest vitality of pupae (P<0.05). Likewise line of 31 significantly (P<0.05) had the superior performance in comparison to other lines from the aspect of single weight cocoon. Also line of 31 significantly (P<0.05) showed the highest cocoon shell weight. Furthermore line of 32 showed the highest percentage of cocoon shell significantly (P<0.05). Likewise lines of 103 and 31 had the superior average of the best cocoons yield.

German cockroach is one of the worldwide pest with high potential of reproduction, and a carrier of many pathogens and allergen factors in human. Thus, control of this insect is very important from the view point of public health. In this research, the contact effects of pyriproxyfen on histological structure of internal reproductive organs of German cockroach were investigated. The last instar nymphal stage were treated with different concentrations (10, 1, 0.1, 0.01 and 0.001 ppm) of pyriproxyfen until the adults were emerged. To investigate the effects of juvenoid on reproduction, each of the treated insects were kept with an untreated opposite sex leading to the formation of the first egg capsule. Then, for histological investigations, the reproductive organs removed. Morphological studies on treated insects and their reproductive organs compared with untreated insects showed that pyriproxyfen in high concentrations caused sterility of the insects due to incomplete development of the these organs in both sexes, and the imagoes were not emerged either. Histological investigation of testis and ovaries in infertile insects indicated degeneration of ovarian follicle cells, defective vitellogenesis, hypertrophy of testis walls, spermatogenesis disorder and a decrease in the number of spermatocyts and spermatozoa.

Assessment of sperm parameters in Associated Reproductive Techniques (ART) such as Intra-Cytoplasmic Sperm Injection (ICSI) and In Vitro Fertilization (IVF) is very important. Some of the factors considered in selection of infertile males for treatment by ICSI and IVF procedures, are sperm concentration, motility and morphology. There are several markers for assessment of sperm maturation, such as; plasma membrane remodeling and formation of receptor for sperm Hyaluronic acid (HA) binding. The aim of this study, survey relation between sperm binding ability to hyaluronic acid with human sperm parameters. Semen samples from 36 infertile couples referring to Isfahan Fertility and Infertility royan center were assessed during this study. Sperm parameters such as morphology (Papanicolaou staining), motility and density were assessed according to WHO criteria. By incubating sperm to hyaluronic acid within microinjection dishes, percentage of sperm binding to hyaluronic acid was assessed. Percentage of sperm bound to hyaluronic acid has significant negative correlation with percentage of abnormal morphology (P=0.001, r = -0.524), whereas a significant positive correlation was obtained with sperm concentration (P=0.002, r = 0.499) and motility (P=0.015, r = 0.402). According to result of this study concludes sperm selection for ICSI can be carried out based on the ability of sperm bind to hyaluronic acid.

Down syndrome is the most common chromosomal abnormality associated with mental retardation affecting 1/800 in live births. The origin of extra chromosome 21 has been shown to be maternal in 93% of cases, with 7% of cases due to paternal non-disjunction. Impairment in folate metabolism due to common polymorphism in enzymes coding genes in folic acid pathway is one hypothesis in etiology of chromosome 21 trisomy. Cystathionine beta synthase is a key enzyme in this cycle. In this study, we investigated 844ins68 polymorphism this gene, in Iranian mother having Down syndrome child. We have studied 93 mothers with DS children and 116 control mothers. Genomic DNA was extracted from blood Leukocytes by salting out procedure. DNA analysis was carried out by PCR amplification of a DNA fragment containing exon 8 of the CBS gene. Prevalence of 844ins68 polymorphism was investigated in both case and control mothers group. Frequency of polymorphism were 8 (8.6%) in Iranian mother cases and 18 (15.5%) in control mothers. No Homozygous mother was found for mutation in both case and control group. Statistical analysis showed no association between 844ins68 polymorphism in cystathinine beta synthase and risk of Down syndrome in Iranian population (P=0.146).

Removal of organic sulfur compounds is important because of causing environmental pollution. In this research a strain of Trichosporon was isolated from phenol contaminated wastes that was able to utilization phenol and dibenzothiophene (DBT), as a model cyclic sulfur compound. The yeast was able to remove 0.3mM DBT from BSM medium in 14d by co-metabolism reaction with other carbon sources. This strain was used for detection of growth characteristics on DBT as sole sulfur source by microtitre plate assay. In BSM medium containing DBT with various carbon sources including ethanol, glucose, glycerol and succinate, Trichosporon had the best growth on glucose and succinate. Also this strain had highest respiration on succinate and biofilm formation on ethanol. Microtitre plate assay showed that the yeast had highest growth in 0.3mM DBT and was able to grow in 0.1-4 mM; also it was tolerated to DBT up to 10mM. The yeast had highest growth and respiration on 0.1 mM HBP. In presence of inorganic sulfur as sole sulfur source in 1.4mM the growth and respiration was higher than in DBT as sulfur source. The maximum growth of Trichosporon was in pH 6.5. This strain did not grow on solvents such as acetone, ethylacetate and dimethylformamide in presence of DBT and glucose, and only grew on ethanol as solvent or sole carbon source.

Staphylococcal enterotoxins (SEs) are emetic toxins and are one cause of food poisoning in humans and animals. These toxins have been divided into more than fifteen serological types (SEA through SEQ) on the basis of their antigenicities. However, the relationship between these SEs and human food poisoning is not fully understood at present. Recently a new type of SE (SEQ) has been repoted, which the gene of seq is encoded by a genomic island, νSa1 (SaPI3). For detection of staphylococcal enterotoxin Q gene, the 95 Staphylococcus aureus isolates were confirmed by biochemical test. Primers were designed and the PCR was used to amplify the staphylococcal enterotoxin Q gene (seq) and the staphylococcal nuclease gene (nuc). DNA amplification fragments of 397 bp for the staphylococcal nuclease gene (nuc) and 122 bp for staphylococcal enterotoxin Q gene (seq) was confirmed by digestion enzymes. Among the 95 isolates, only eight (8/4%) isolates were associated with the seq gene. This is the first report about Staphylococcal enterotoxin Q in Iran.

Extracellular lipase production was studied in a Gram-negative moderately halophilic bacterial strain that was isolated from Garmsar river and temporary identified as Salinivibrio sp. ZG13-2 by phenotypic characterization. Lipase activity and stability were assayed with Paranitrophenyl butyrate as a substrate in different pH values, salts and temperatures. The optimum conditions for lipase secretion were: pH8, temperature 35°C, aeration 150 rpm, NaCl 1M and olive oil 2%. Carbohydrates (glucose, galactose, fructose and starch) and glycerol didn’t induce lipase production. The maximum lipase activity was at NaCl 1M, pH 7.5 and at 50 C and CaCl2 0.01M. Lipase Enzyme was stable at pH 7.5-8 for 4 hours and retaining 90% activity in 80 C for 30 minuets. Different concentrations of salts have no effect on stability.

Manipulation of regulatory elements is usually considered as a major act for the improvement of production of recombinant proteins. In this regard introns with the potential of regulatory function have provided useful means. Human beta globin gene has two introns with 130 and 850 bp lengths, in silco analysis of these two introns show that they carry a number of potential regulatory elements which make them useful to be applied for the expression of recombinant proteins in mammalian host cells. With the aim of the production of recombinant human factor IX (hFIX), a hFIX minigene carrying the human beta globin introns (hBGIs) was inserted in a CMV regulated vector. In the constructed vector the hBGIs was inserted in the corresponding position in hFIX-cDNA. In a separate line an intron-less hFIX-cDNA was inserted in a similar vector to be used as negative control. Chinese Hamster Ovary (CHO) cells were transfected with the constructed plasmids, based on lipofectoin method. The culture media taken from the transfected cells were examined for coagulation activity with a single stage clotting test performed on FIX-deficient plasma. The data obtained from the expression analysis of the two groups of transfected cells in comparison with the cells with the intron-less cDNA indicates in the expression of hFIX by both groups of cells. The same data shows a relatively higher coagulation activity in the culture media taken from the cells with intron-containing hFIX-cDNA.