مجله زیست شناسی ایران
سال بیست و یکم شماره 2 (تابستان 1387)

The Hyoscyamus genus has been always regarded as a medical herb because of the therapeutic effects attributed to its contained tropan alkaloids. Hence, propagation of this plant in a fast and cost-effective manner is very important. Somatic embryogenesis is a great help in this field. The aim of the current study is to gain knowledge about mechanism of somatic embryogenesis via protein change's assessment in different stages of embryo formation. In this study leaf culture on MS medium containing BAP and IAA lead to embryogenesis. Quantitative protein evaluation in different stages of embryo development showed changes in protein content. The qualitative evaluation of proteins was performed using electrophoresis of two types of poly-acryl amide jells in discontinued system (PAGE and SDS-PAGE). Molecular mass of peptide as well as peptide separated bonds were calculated, and it cleared that during embryogenesis different proteins and peptides undergo up-regulation, down-regulation, and modulation. In addition, main and fundamental proteins and peptides were known.

In many aquaculture operations where selected rotifer species are mass cultured for feeding fish larvae; it is considered highly desirable to provide the optimal prey size for maximizing larval survival and growth selection. A suitable strain and manipulation of culture conditions (algae food quality and quantity, temperature and salinity) are two possible approaches towards this goal. Laboratory population of the rotifer Brachionus calyciflorus were grown with two green algae (Chlorella sp. & Scenedesmus obliquus) at different food densities (0.1, 1, 10×106 cell/ml). The body size (lorica area) of individual rotifers and the size of eggs borne by them were measured at k-phase of population growth. The body size of rotifers fed Scenedesmus obliquus was larger with compared those fed Chlorella sp. The body size of rotifers fed higher food level (10×106 cell/ml) of Chlorella sp. significantly larger than those fed lower and medium levels(0.1, 1 ×106 cell/ml). Rotifers fed Scenedesmus obliqqus at 1×106 and 10×106 cell/ml density grew to a significantly large size(p<0.05) than fed at 0.1×106 cell/ml density. The size of eggs produced by adult females significantly larger at higher food level of both Chlorella and Scenedesmus. A significantly positive correlation was also observed between the adult body size and the size of egg produced.

Knowledge of patterns of genetic diversity enhances the efficiency of germplasm conservation and improvement. In this study 96 Iranian landraces of Triticum turgidum var durum was originated from different geographical areas of Iran, and 18 durum cultivars from ten countries were evaluated for variation in high molecular weight glutenin subunit (HMW-GS) composition. Three alleles were present at the Glu-A1 locus and 11 alleles at Glu-B1. In both cultivars and landraces of durum wheat, the null allele (Glu-A1c) was observed more frequently than the Glu-A1a and Glu-A1b alleles. Two alleles, namely Glu-B1a (subunit 7) and Glu-B1e (subunit 20) represented the most frequency alleles at Glu-B1 locus. The results showed that the evaluated Iranian landraces formed an interesting source of favourable glutenin subunits that might be very desirable in breeding activities for improving pasta-making quality.

Drought stress is one of the most important environmental factors that it is effective on growth, development and production of plants. This investigation was conducted to evaluate the effects of the drought stress on seed germination of carthamus cultivars, in order to an experimental factorial was conducted based on randomized complete block design (CRD) with three replications. The experimental factors were four cultivars (Hatman,CW-74,Yenice and LRV-5161) with five levels water stress (0,-2,-4,-6,-8 bar). The results showed that different treatments of drought stress had considerable effect on the germination percentage, uniformity of germination, radicule and plumule weight, proportion of radicle to plumule and seedling total dry matter. Increasing osmotic potential decresded germination percentage, it the amount was 81/02% in control treatment and 6/03% osmotic potential -8 bar. The highest germination percentage was belonged to CW-74 cultivar (62/9%) and the least it was in Yenice cultivar (42/66%). Maximum uniformity of germination was obtained in control treatment and the least it was in osmotic potential -6 and -8 bar. Cultivars had different response to drought stress. Minimum uniformity of germination was obtained in LRV-5161 cultivar (with 53/47 hours) and maximum it was in CW-74 cultivar (with 42/71 hours). Under water stress condition CW-74 cultivar had longer radicle and higher proportion of radicle to plumule than the other cultivars. Study of the other parameters such as radicule and plumule weight, seedling total dry matter showed that CW-74 cultivar was more resistance to water stress.

Drought stress is a major constraint to rice (Oryza sativa) production for which the reproductive period is the most sensitive stage. One of the most important reasons for the impact of drought is the inhibition of peduncle elongation, resulting in panicle retention inside the flag leaf sheath so that the unexserted spikelets remain sterile. This research was focused on studying the peduncle elongation pattern in rice plants under well-watered and drought-stress conditions as well as analyzing the effects of phytohormones (gibberellic acid, abscisic acid and auxin) on elongation of detached peduncles. The inhibitory effect of drought stress on peduncle elongation was observed since leaf rolling up to the end of stress time. After re-watering, the peduncles did not achieve the same length as well-watered plants, since there is only a limited opportunity for peduncle elongation. Peduncle elongation in an elongated uppermost internode IR64 mutant, eui-10, is also inhibited by drought stress. However, after re-watering, its peduncle grew even longer than well-watered IR64 plants in the limited time left. As the peduncle elongation rate of this mutant is much higher than IR64, panicle is fully exserted. In order to study the effect of candidate hormones on the peduncle elongation, a simple and efficient experimental design was employed. The peduncles were detached from the tillers at heading stage, and floated in the desired solutions. The presence of auxin (IAA) had no significant effect on the elongation of detached peduncles while gibberellic acid (GA3) activated peduncle elongation in a concentration dependent manner. Abscisic acid (ABA) antagonized GA effect leading to complete inhibition of peduncle elongation. The effect of GA, as an inducer, and ABA, as an inhibitor, on peduncle elongation was highly significant in Moroberekan (japonica rice), IR64 (indica rice) and eui-10. These data indicate the possible role of hormonal control on peduncle elongation in response to drought stress.

Studies have shown that salicylic acid (SA) is the caused of resistance the plants to environmental stress (cold, heat, salinity and drought stress). The effects of salicylic acid are probably caused by inhibition of ethylene biosynthesis. In this research the effects of ethylene and salicylic acid treatments on the quantity of carotenoid, anthocyanin, flavonoids, lipid peroxidation, ascorbic acid, dehydroascorbic acid and total ascorbate in leaves of canola were studied. The plants were grown in pots until they grow to 4 leaf stages. Therefore the leaves were sprayed with salicylic acid at 4 levels (0, 0.5, 1 and 1.5 mM) lasted for 2 days. Plants were treated with 4 level of ethylene (0, 50, 100 and 150 ppm) for 3 days. Triton X-100 was used as surfactant. At the end of ethylene treatment parameters were measured. Study showed that in those plants which were treated with ethylene and salicylic acid (lower than 1mM), anthocyanin were decreased. Combination treatment of salicylic acid and ethylene caused significant increase in flavonoids, ascorbic acid, dehydroascorbic acid and total ascorbate. Lipid peroxidation in plants that were treated with either salicylic acid or ethylene was increased significantly but combination treatment with salicylic acid and ethylene caused decreased in lipid peroxidation. Our results showed that salicylic acid at 1mM concentration or lower can be used as a antistress agent to reduce oxidative stress caused by ethylene but salicylic acid at 1.5 mM salicylic acid will enhance stress. Therefore we concluded that application of salicylic acid at lower than 1mM can protect plants against oxidative stress.

The objective of the present study was to investigate the effect of electromagnetic field (88 and 128 µT) and exposure times (12 and 24 hours for weed seeds and 10 and 30 minutes for crop seeds) on annual medics (Medicago radiata, Medicago scutellata and Medicago polymorpha), barley (Hordeum vulgare), dodder (Cuscuta monogyna) and barnyard grass (Echinochloa crusgalli) seed germination. There were differences among different treatments (P≤0.01) for root, shoot and seedling dry weight in barnyard grass. Fresh weight and seedling vigor index were different between treatments (P≤0.05). There was no significant difference among treatments for germination percent, index and rate coefficient in barnyard grass. Electromagnetic intensity affected root dry weight of barnyard grass and increased this parameter in comparison with control. There were differences among treatments for germination percentage, shoot length and dry seedling and shoot weight and seedling vigor index in dodder seeds (P≤0.01). Seedling vigor index and dry weight decreased in dodder seeds under different electromagnetic intensity. Electromagnetic intensity enrichment increased germination rate and percentage and shoot length of annual medic species. The greatest germination rate and percent of crop seeds were obtained at electromagnetic intensity of 128 micro tesla, when they exposed for 10 minutes.

Rotaviruses are recognized as the most important cause of sever diarrhea illness of infants and children world-wide. These viruses consist of triple-layered protein capsid The inner layer is composed of VP2. In this study, the expression of VP2 gene of the bovine rotavirus RF has been evaluated in human epithelial lung cells (A549) under CMV promoter. First, the rotavirus gene was cloned in pcDNA3 plasmid and then recombinant plasmid transferred to a human lung epithelial cell line by a carrier namely dendrosome. Western blotting analysis has revealed expression of the gene in the cells after 48-72 hrs post infection. The expression of VP2 gene was confirmed by observation of core like particles (CLPs) with electron microscopy and immunocytochemistry by using gold conjugated protein A. The results indicated that the used eukaryotic cells in this study can serve as a suitable host for expression of VP2 gene; since the cells expressed the proteins correctly and made the VP2 protein to be self-assembled and form native structure.

In recent years, Microthrix parvicella has been identified as the main element of sludge bulking in wastewater treatment plants by activated sludge process.

(1) the measurement of lengthy chain of fatty Acids (2) Pilot study.(3) Laboratory Study.(4)Microscopic Study.

(1) Microthrix parvicella is a gramm positive bacteria. Its presence in the urban wastewater treatment plants depend on the low Sludge loading (less than 3 grams of the lengthy chain fatty acid for each kilogram of solid material per day.) (2) The critical Growth of the bacteria is being observed at less than 15º Celsius. (3) The utilized main substrate of the bacteria is the lengthy chain fatty acid.(4) The bacteria is being accumulated in sludge foam where there is a suitable place for the Growth of the bacteria.(5) Polyaluminum chloride (PAC) will prevent the Lipase production as well as Enzyme activity of the bacteria, consequently, it has negative effect on the amount of substrate absorption(hydrolysed fats) by the bacteria. If 2 to 3 grams of Al3+ are used for each kilograms of solid material per day, which is selected proportionate to the sludge life, the bacteria can be eliminated completely. (6) If the primary sedimentation is utilized for about 20% eliminated load of the solid material, concerning the remarkable elimination of mentioned bacteria, there is not a noticeable change in the Sludge volume index.

Listeria monocytogenes is a gram positive bacterium which through the contaminated foods causes Listeriosis in the human and abortion in livestock. This bacterium is widely available in the nature that the possibility of the food contamination is very high. Therefore, one of the possible ways of controlling the bacterium in the food and environment is the biocontrol of this bacterium. For this purpose bacteriophages might be used. To get rid of bacteria using phage depends on complex physical and chemical conditions. In this study we evaluated the effect of pH and temperature for 5 separate phages from lysogenic Listeria monocytogenes of aborted fetus on 4 strains of Listeria monocytogenes. The common bacteria in the ewes’ fetus abortion in different regions of Isfahan were investigated for two years. Lysogenic Listeria was inculcated in liquid medium. Five Listeria phages were extracted by a 0.45-μm filter. Then, 5 phages with a titer of 109 PFU/ml were selected and mixed together. Subsequently the selected mixtures were poured equally into 3 test tubes. The tubes’ pH s was adjusted to 4, 7, and 9. At temperatures 0◦ to 7◦C, 8◦ to 14◦C, 15◦ to 25◦C and 26◦ to 37◦C 2.5ml of each bacteriophages mixture with the same pH were mixed separately with 4 strains of Listeria monocytogenes and were incubated for 24 hours. Thereafter, a drop of each tube’s content was cultured on the blood agar. Lytic or lysogenic colonies of the bacterium were assessed. More than 2/3 of Listeria monocytogenes causing the abortion in the ewes are in lysogenic forms. The best pH for the attachment of the bacteriophages to the host bacterium is a neutral pH. To transform the bacterium into all pH s, a wide temperature range of (15◦C to 37◦C) was used. There was a significant difference (p = 0.0 5) between the formed lysogen from the bacterium having a 1<pH<7 and worth mentioning the bacterium form was transformed to lysogen forms. For biocontrol of Listeria monocytogenes in the environment and foods it is essential to know all the effective factors for the bacteriophages attachment to the Listeria monocytogenes and the conditions of the infected cells with the bacteriophages.

In order to study the activity of Thiobacillus ferrooxidans bacterium on bioleaching process and also to evaluate the optimum copper recovery from sulphidic ores, various w/v percents of this ore containing 0.62 percent copper were applicated on basal medium of this bacterium. Every four days, the amount of copper, ferric ion and pH of the solutions were measured. The results of measuring showed that the pH on total solutions was decreased. Amounts of released copper by bacteria were increased on the total of treatments versus the time. The highest released copper was observed on 50 and 60 percent w/v sulphidic ores which was 93.1 and 94.7 percent respectively. The amount of ferric ion increased on 1- 10 w/v percent sulphidic ores versus the time. The highest ferric ion was observed on 20 percent w/v sulphidic ores. The concentration of ferric ion was increased on 20 – 70 w/v percents during the first 20 days and then was decreased. The color of culture media changed more than 20 w/v percent sulphidic ores. The results of this study are effective on bioleaching practical plan in order to optimize copper recovery from sulphidic ores.

degrade the β-1,3 glucan a biopolymer into its component residues by breaking the β-1,3 glycosidic bonds. As a producer of a variety of glucacase enzymes, the filamentous fungus, Trichoderma, has become an important means of biological control for fungal diseases. The bgnI gene encodes one of the glucanase enzymes which can be used for degradation of β- glucan rich cell wall of various fungal phytopathogenes. In this study two specific primers (RbgnI/FbgnI) and genomic DNA from T. virens (10) with high β-1,3 glucanase activity were used for bgnI amplification. The amplified DNA fragment (about 2.3 kb) was analyzed by restriction pattern using HindIII, pstI, SalI, EcoR1, BamHI and HindII enzymes. BamHI, pstI, HindII and SalI demonstrated unexpected pattern. The amplified fragment was cloned into pUC19 and designated as pUCRM1. The cloned DNA fragment was sequencedand compared with those deposited in NCBI, confirmed the sequence of bglI. This gene is 2345 bp long and contains a short (65 bp) intron and open reading frame encoding a polypeptide with 760 amino acid and molecular weight of 79.4 kDa. The deduced polypeptide shows 60 to 91% homology with other reported related polypeptides.

In this study, the suitability of three live traps including sherman, havahart and locally made traps were investigated for rodent sampling. Traps were distributed as sampling points on the line transect. At every station, three types of traps were used. Traps were checked the next morning to record the species caught. A total of 195 rodents belonging to 7 species were trapped, included: Calomyscus bailwardi, Acomys cahirinus, Rattus rattus, Tatera indica, Gerbillus nanus, Meriones persicus and Meriones lybicus. A significant difference was identified through comparison of the success of traps in the rodents sampling. In this regard, sherman traps showed the highest rate of success(6.88 %), while the locally made traps indicated the least success rate (2.83 %). More over, a significant difference was identified between the rodents species and the different types of traps (P<0.05). For example, Significant differences was in the success of traps for caught of C. bailwardi (P<0.05) and A. cahirinus (P<0.05), but for R. rattus (P>0.05) and T. indica (P>0.05) there was not significant differences.

Study about systematics of the species and subspecies of the saw-scaled viper (Echis) has not come with decisive results. Latifi (2000) recorded only one subspecies of saw-scaled viper Echis carinatus sochureki Stemmler 1969 from Iran. For analysis systematic status of this genus, 47 specimens from the Gheshm, Bandarabas, Turan, Shiraz, Damghan, Zabol and Tabas were examined based on 12 meristic, six morphologic and two morphometric characters. Statistically significant difference demonstrated between the south populations (Gheshm and Bandarabas) and central-north populations (Turan and Tabas) based on ventrals (P<0.001), obliques (P<0.002), dorsals (P<0.001) and circumorbitals (P<0.001). Hotelling T2 test (permutation with 2000 randomzation) showed significant differences between mean vectors of the characters in the mentioned populations (P<0.005). Principle coordinate analysis (PCO) of the our specimens in compare with E. c. sochureki from Pakistan and Afghanistan and E. multisquamatus cherline 1981 from Middle east and Afghanistan ordinate the south populations with the E. c. sochureki and the central-north population with E. multisquamatus. Cluster analysis classified the central-north population with E. multisquamatus specimens, that described by Cherlin, in the same cluster.

Among injurious mites on ornamental plants identified in indoor and outdoor conditions, some species reported as a major pests in Iran and other parts of hhe world. An investigation of injurious and predacious ornamental plant mites were carried out in controlled and natural conditions in three main ornamental growing regions (Tehran and Markazi, Esfehan Provinces) in Iran during 2002-2003. More than 100 ornamental plant species belong to 45 botanical families were checked which 81 of them along with 17 weed species belonging to 11 botanical families were observed as mite harboring. Six spider mite species in three genera found injurious which host ranges of Tetranychus urticae, T. cinnabarinus observed with more than 70 ornamental species. Botanical families of Asteraceae and Araceae observed with maximum host plant species. Four species of Tenuipalpid mites from 7 host plants identified and population and damages of Brevipalpus sp. on Agloanema commutatum and Cissus rhombifolia found higher than other one. Phytocoptella yuccae damages on terminal leaves of Yucca gloriosa caused white powdery spots d at based of leave along with growth retardation which led to ugly appearance of infested Y. gloriosa leaves under controlled condition. Rhizoglyphus robini and R. echinopus (Acaridae) injuries on bulbs of Gladioulus grandiflorus, Polianthes tuberose caused noticeable damages and protect normal bulb growth in large infested area. Density population of an unidentified oribatid mite on petals of Anthurium andraeanum caused brown spots appearance of infested plants in some greenhouses in Varamine region. Among predacious mites from Tydeidae, Trombidiidae, Euplapsellidae, Phytoseiidae Parasitidae families collected on some ornamental plants, only two phytoseiid species i.e. Neoseilus umbraticus and Phytoseius sp. observed in less number on Magnolia grandiflora and Peteris cretica respectively. Maximum host ranges of predatory mites recorded for tydeid mite in comparison to other.

In this investigation the effect of paraquat in concentrations 10, 15 and 20 mg/ kg b.w. have Been worked out in spematogenesis of Balb/C mice. The male mice from 9-10 weeks old age received above mentiond paraquat for two weeks intraperitoneally. The studied variables were the body weight,weight of testis, volume of testis,cell counting inside seminiferous tubules including sertoli cells, spermatogonia, primary spermatocytes, spermatids, sperm and Leydig cells, hormonal assay and fertility.The results of this study showed no significant effect on the body weight and weight of testis. Furthermore, a significant decreasing FSH level was detected in animals treated with paraquat. Also fertility was decreased in treated groups. It is suggested that paraquat may decrease cells kinds into seminiferous tubules in Balb/C mice in male repoductive system and its may decrease fertility ability.

Use of medicinal plants for attenuation of hyperglycemia and restoration of lipids to normal level is clinically important. In this respect, there are evidences for antidiabetic potential of derivatives of Allium latifolium (AL). Therefore, the effect of chronic oral administration of this plant on serum glucose, triglyceride, total cholesterol, and HDL- and LDL-cholesterol level of diabetic rats was investigated. For this purpose, male Wistar rats (n = 32) were randomly divided into 4 control, AL-treated control, diabetic, and AL-treated diabetic groups. The treatment groups received oral administration of plant-mixed pelleted food (6.25%) for 6 weeks. Serum glucose, triglyceride, total cholesterol, LDL- and HDL- cholesterol levels were determined before the study, and at 3rd and 6th weeks after the study. Serum glucose level in diabetic group increased 6 weeks after the experiment as compared to data one week before the study (p<0.001) and AL treatment of diabetic rats did have a significant hypoglycemic effect (p<0.01). In addition, triglyceride level in diabetic group increased 6 weeks after the experiment in comparison with related data one week before the study (P<0.05) and there was no significant change in this parameter in AL-treated diabetic rats.. Furthermore, a similar significant reduction was obtained for treated-diabetic group as compared to diabetic group regarding serum cholesterol level (p<0.05). On the other hand, HDL- and LDL- cholesterol levels were significantly higher (p<0.05) and lower (p<0.01) in AL-treated diabetic group as compared to untreated diabetic group respectively. Therefore, oral chronic administration of AL has a significant moderate hypoglycemic effect and leads to appropriate changes in total cholesterol, HDL- and LDL-cholesterol levels.

Zinc is an essential dietary element for many biological processes that modulates neurotransmission in brain regions. Zinc is also necessary for many homeostatic processes in the brain, some of which indicate neurotransmitter function. Zinc is essential for normal central nervous system development and function. Imbalances of this metal, either excess or deficiency, can result in neuronal apoptosis. Some researches indicate that zinc deficiency in animals cause to malformations and abnormal motility and motor coordination. But other researches has been shown, that the level of zinc in Parkinson disease unchanged or increased. In this study, we examined the effect of the different doses of Zinc Supplementation on motor activity in young male rats, with rotarod. To evaluate the peripheral effect, oral administration of zinc chloride in five different doses (20, 30, 50, 70,100mg/kg/day) for two weeks were used by gavage methods. The criteria which have been used for the movement test were motor resistance and coordination. This experiment showed that among of the different doses of zinc chloride, just 30 and 50mg/kg/day doses had positive effect on motor coordination (P<0.05). Motor coordination in groups which received zncl2 (100 mg/kg/day) were decreased (P<0.05).