IRANIAN JOURNAL OF BIOLOGY
Year:2004 | Volume:16 | Issue:4|Papers Count:9

Fusarium wilt caused by Fusarium oxysporum is an important problem in Chick-pea (Cicer arietinum). This disease is one of the most effective factors of Chick-pea crop losses in the West and North-west of Iran. Fusarium oxysporum produces a wide range of enzymes including polygalacturonase capable for degradation of the structural components of the plant cell wall.Purification of polygalacturonase enzymes from isolate F23 of Fusarium oxysporum was achieved by cation exchange chromatography on CM-Sepharose Fast Flow column equilibrated to pH 5.5 with 50mM sodium acetate buffer. Elution of the column was carried out with 1M NaCl gradient. The presence of PG enzymes was investigated by SDS-PAGE. The results showed two distinct bands, about 38 and 40 kDa in isolate F23. These two bands showed PG activity in gel containing pectin as substrate (Zymogram). The optimum pH for enzyme activity before and after purification was determined to be about 4.5

Biological species is a biosystematical Unit Which replaces in time and space and makes with them a unique system, which moves and evolves. In this research 384 specimens of house mouse from Khorasan and Sistan-Baluchistan provinces were studied and compared with the data. from Mediterranean Basin populations which are derived from Iranian plateau house mouse. The study of molars character states on the basis of the polarity indicates that the house mouse of Eastern Iran is older and more polymorphous than Mediterranean Basin house mouse. Also in North-Eastern Part of Iran we have M. m. musculus subspecies that is distributed until Gonabad and the unknown subspecies of Oriental type, that is distributed towards Chah-Bahar.

Since the stress influences the biological processes, in the present study the effect of prenatal immobilization stress and testostrone treatment of male rats were studied. Adult male and female wistar rats were copulated. Pregnant rats were divided into control and experimental groups. All groups were kept under the laboratory conditions (controlled temperature and photoperiod). The pregnant control rats were under no stress. Experimental groups were put in the special adjustable restrainer for 2 house every day for one week from the beginning of the. third week of pregnancy (14 th day) which is the development period of the nervous system, the sexual dimorphic nucleus and probably other nuclei of brain. The male off springs of control and stress group at the age of 80 days were divided in 5 groups. Four groups received respectively 50, 125, 200, and 300 mg Testosterone Enantate through IP injection for one week. The 5 th group received vehicle. At the age of 87 days fear behavior was measured by using elevated plus maze and different parameters were observed. Our results showed that injection of 125 ug testosterone decreased fear behavior comparing with controls which is probably through the inhibitory effects of testosterone on hypothalamus - hypophysis - axis (HPA). Prenatal stressed comparing with control were more fearful. This effect is because of the changes in some brain nuclei and increase of corticotropin releasing hormone (CRF). In conclusion it seems that prenatal immobilization affects fear behavior and testosterone treatment dose dependently decrease this behavior.

To acquire a biochemical marker of carbohydrate in the different ecological conditions and season in Eucalyptus camaldulensis, E. froticetorum and E. viminalis, this study were done. The materials were the new shoots of trees. These materials were collected during winter (January), spring (May) and summer (July) from Zagheh-Marz (in Mazandaran province), NoorAbad-eMamesani (in Fars province) and Malavi (in Lorestan province).The non-structural carbohydrates were extracted. These sugars were quantitatively and qualitatively analyzed based on spectrophotometry, thin layer chromatography, gas liquid chromatography and gas chromatography-mass spectrometery. The reducing sugars (monosaccharides), non-reducing sugars (oligosaccharides) and polysaccharides differed from 3.45 to 18.9 mg/g DW, 10.2 to 47.3 mg/g DW and 8.18 to 25.77 mg/g DW respectively among of species and zones. The decrease of polysaccharides were accompanied by increase in the reducing sugars. In the zones with cold winter and hot summer, free sucrose and raffinose were increased, which played a role in the stress tolerance. The monosaccharides were identified as glucose, fructose, ramnose, xylose, fucose and ribose and uronic acids such as galacturonic acid and glucuronic acid. Sucrose and rafinose were identified as oligosacharides. Maltose is an oligosaccharid that is present in the most of plant species but no trace of maltose was detected in this study. There were no any starch or fructanic polymer as a polysaccharide in the studied Eucalyptus species. The structural monomers of storagepolysaccharide were identified as glucose, galactose, arabinose-mannose, ramnose, xylose, galacturonic acid and glucuronic acid. These monomers are the same as pectinic compounds, which are found in the cell wall compositions. The gas liquid chromatography showed that in regions with cold winter, the structural composition of polysaccharide were more glucose-galactose as monomer than arabinose-ramnose. Because in these conditions the storage polysaccharide is degradaded and then structural monomers for producing raffinose and its galactosides is produced. The produced oligosaccharides play in role of tolerance to cold stress via decreasing of melting point of water tissue and increasing of vacuolic syrup concentration.

The biochemical responses of some olive cultivars was evaluated to select drought resistant cultivars for olive orchard developing in Iran. One-year-old and two-year-old olive (Olea europaea L.) trees cvs. Mary, Zard, Roghani, Blidi and Mission grown in 14 liter pots containing a mixture of sandy loam soil (62% sand, 24% silt and 14% clay ), were subjected to various levels of water stress. Irrigation treatments were control (soil water at field capacity, ψsoil = -0.03 MPa), mild stress (ψsoil = -0.5 MPa) and severe stress (ψsoil = -1.5 MPa). A factorial experiment based on randomized complete block design was used. Results indicated that the degree of water stress had significant effect on the amount of proline. During of the first experiment, Roghani, Blidi, Mary, Mission and Zard olive cultivars had higher proline content respectively. Increasing of proline content in Blidi, Mary and Roghani olive plants under mild drought stress was higher than other cultivars in greenhouse experiment. Mary, Roghani, Blidi, Zard and Mission olive cultivars had higher proline content under severe drought stress respectively. There was a reduction on proline content after rewatering. It was due to proline instability. Exposure of plants to drought conditions led to noticeable increases in soluble carbohydrate concentration. The amount of soluble carbohydrate increased with increasing of level of drought stress. During of the first and second experiment, Mary, Roghani, Blidi, Zard and Mission olive cultivars had higher soluble carbohydrate content respectively. Plants of Mary, Roghani and Blidi cultivars had significant increase of soluble carbohydrate under mild drought stress in compare with other cultivars. Also, Plants of Mary and Roghani cultivars had significant increase of soluble carbohydrate under severe drought stress in compare with other cultivars. The amount of soluble carbohydrate decreased in the later part of experiment, it may because of use and transport to the roots.

The genus Cirsium Adans, one of the genera in Asteraceae, has 250-300 species distributed over the world. According to Flora Iranica (Rechinger) there are 5 sections, 7 subsections, 28 species, 4 subspecies and 10 vrieties in different regions of Iran. This study was carried out on the existing species found in Khorasan, Which include 10 species. Among Cirsium species, 8 species were investigated in detail of systematical point of iew. Cirsium congestum Fisch& C.A.Mey.,C Bornmulleri Sint. Ex Bormn, C. strigosum (M.B.) M.B., C, osseticum (Adams) Petrak, C. turkestanicum (Regel) Petrak., C. vulgare (Savi) Ten., Crhizocephalum C.A. Mey., C. arvense (L) Scop.The specimens were collected and were dried with the usual methods of herbarium specimens and different parts of them (organs) were studied with stereomicroscope and drown. This investigated aimed to provide the identification and distribution maps of the Cirsium species. The presentation of the relevant keys has been done according to fundamental characters. In this study 62 qualitative and quantitative characters of taxawere recorded for a numerical taxonomy. Finally, the species were analyzed with the help of the software SPSS and through cluster analysis ward's methods. These studies showed that the Cirsium species have more differences in leaf are a dominant character in discriminating between the species. For example: in C. congestium and C. turkestanicum the baxial surface of leaf are covered with more and less of spiders web trichoms, and croweded Spiders web trichoms, respectively. The results of Cluster analysis assert the classic classification. For example: The two species, C. strigosum and C. oseticum (Sec. Epitrachys) have more affinity to each other but there are little affinity between the C. congestum (Sect. Pseudepitrachys) and C. rvense (Sect. Cephalonoplos). So, the results proved taxnomic studies are important in systematic of investigated species and through these information which phylogenetic relation of species can be determined.

Ghameshloo Wildlife Refuge, that has been protected since 1975, is situated in 45 km. northwest of Esfahan (in central Iran). This area is one of the important habitat for Esfahan wild sheep race (Ovis orientalis Gmelin subsp. isphahanica Nasonov). The area covers a surface of ca 50,000 hectars with an elevation ranges between 1800 meter to 2654 meter above sea level. The climate of the area is generally cold and dry in winter and hot and dry in summer. In present work, for the first time, the floristic compositions of the area has studied. The results showed that 497 species belonging to 266 genera and 57 families of vascular plants are grown in this area, among which, the family Asteraceae with 80 species and the genus Astragalus with 37 species are known as the largest family and the largest genus respectively. Furthermore, the plant life form spectrum snowed that these plants consists of 52% hemicryptophytes, 26% therophytes, 11% chamaeophytes, 9% geophytes, and 2% nanophanerophytes. The dominance of hemicryptophytes indicates the harsh and difficult environmental conditions in this area.