IRANIAN JOURNAL OF BIOLOGY
Year:2007 | Volume:20 | Issue:2|Papers Count:18

There is not enough information about the effects of various environmental factors, on cell division and pigments synthesis in Iranian strain of Dunaliella salina (isolated from salt marsh of Gavkhoni, Isfahan). Therefore, more studies must be carried out. In this study, influence of different concentrations of sulfate on cell division, content of pigments and photosynthesis were investigated. The algal cells were cultured in four concentrations (0, 0.25, 0.75 and 5 mM) of MgSO4. Trend of cell growth, content of pigments and rate of photosynthesis were measured in four replicates during 30 days of experiment. The results showed that sulfate deficiency led to decrease in cell division and content of chlorophyll but increased beta-carotene cell content. Also sulfate deficiency decreased the photosynthesis.

In order to measure the amount of minerals and vitamins in various cultivars of kiwifruits and to compare them with vitamins of orange, varieties of Abbot, Bruno, Hayward and Monti Kiwifruits and Novel Thomson orange were harvested from orchards under the control of Council of kiwi Producer and Research Center of citrus fruit in Tonekabon city, respectively. The fruits were transported to the laboratory and the levels of K, Ca, Mg, Fe, Zn, P, B and Na and vitamins of C, A, E and B1, B2, B3 and B6 were then determined. The results of the analyses confirm that kiwifruit is a rich source of minerals and vitamins; and that their amounts are much higher compared with orange. Comparison of mineral contents in the various cultivars of kiwifruits show that the level of K, Ca and Mg in Brono variety, Fe and Zn in Abbot variety, P and B in Hayward variety and Na in Monti variety are higher. Additionally, the content of vitamins in all the varieties of kiwifruits is high and a significant difference is not present between them but, the comparison between kiwifruit and orange show that the content of vitamin C in kiwifruit is about four times and vitamins B2, B3 (PP) are about two times higher than in orange. However, the content of vitamins A, E, B1 and B6 in Novel Thomson orange are higher than the investigated varieties of kiwifruits.

Eight species from Mn and Cu rich sites in Azerbaijan, NW of Iran, were used for physiologic studies in hydroponic culture medium under environmentally controlled conditions. These species were either important elements of flora of Mn and Cu rich soils or have considerably low frequency on these soils compared to ecologically similar sites. Tolerance to toxic concentrations of Mn and Cu, accumulation in shoot and root as well as uptake kinetics were studied. Alyssum strigosum and Salvia sclarea demonstrated a high tolerance to toxic concentrations of Mn, growth of these species even stimulated significantly in response to Mn concentrations as high as 100 mM. In addition of growth stimulation, a high accumulation of Mn was observed in these species implicated involvement of detoxification mechanisms. In contrast, Acillea millefolium and Chicorium intybus were detected as susceptible and includer species which was in accordance with low frequency of these species in the natural habitat. A high susceptibility to Cu was observed in Papaver somniferum and Chicorium intybus which as associated with a high Cu accumulation in shoot and root. Accordingly, these two species were detected as includer and susceptible species, which was also in accordance with previous ecologic results. Salvia sclarea and two species of Astragalus tolerated high Cu concentrations, in Astragalus species it was attributed mainly to low transport into shoot and sequestration of Cu in roots. Copper uptake parameters in two contrasting species Chicorium intybus and Astragalus aharicus demonstrated that Km was similar between two tested species, but Vmax was higher in Chicorium intybus than Astragalus aharicus. In kinetic study, enhancement of Cu transport into shoot during time course and in response to increasing Cu concentrations in Chicorium intybus was also demonstrated.

Considering appropriate adaptability of different wild Pistacia species in different Arid and Semi-Arid environment of the country as well as its high value from the point of view of Resin and other chemical production, oil, and pharmacological consumption of their seeds, founding their habitats in the different areas of Markazi Province seems to be important. In this study first of all, the basic information including topography, soil, climate, geology, and land use map of the Saghez area of Tafresh which is located between 1850-2030m above sea level with 1/50000 scale were prepared and digitized. Then the boundary of areas covered by wild Pistacia species were visited and recorded by GPS and digitized. In order to study the habitat characteristics of the species, 1 sample plot were taken from the area of 1600m2. The parameters, such as the number of trees in the sample, trees height, trees width, trees diameter in height breast, the crown height and diameter, growth type and, etc were recorded in sampling areas. After establishing the DEM of the areas, aspect and slope map were also produced using dfdx and dfdy filter in ilwis academic program Package. On the basis of this investigation the following result were obtained. Total area covered by the species is 16/2h and the trees density is 45-70 individuals per hectare. Environmental relationship were determined using maps integrating and data overlying such as slop, aspect, height, climate, landuse and soil. The Maximum distribution was observed in SE and the minimum in NW aspects. The Maximum distribution was observed in 10-20 slop degrees.

For studying of woody plants biodiversity in different soils types in two main plant associations under different management system, sampling was preformed systematic randomly with 60 sample plots with an area of 1000 m2 and 200*200m sampling network. The selected surface of two plant associations was 250ha including 125ha per association. For consideration of woody plants biodiversity current indices of diversity, richness and evenness with Simpson, Shannon wiener, Margalef, Menhinick, Pilo and Hip were used respectively. The results showed that Fageto-carpinetum in forest brown soil and Fagetum in memorized brown soil have the most diversity index and Fagetocarpinetum in classic brown soil and bleached brown soil has the lower amount of diversity index.

In this investigation allelopathic potential of some wheat cultivars for in view of weed suppression was studied. The aerial parts aqueous extracts of 10 wheat cultivars (Atrak, Dez, Pishtaz, Chamran, Darab2, Shiraz, Shirodi, Star, Marvdasht and Tagan) at vegetative (27 days after swing) and harvest stages were investigated on germination, shoot and root length, shoot and root fresh/dry weight of H. spontaneum and L. rigidum seedlings. As results the allelopathy of wheat extracts significantly differed among cultivars. Two cultivars of wheat (Chamran, Pishtaz) significantly reduced germination, shoot and root length , dry weight of H. spontaneum and L. rigidum. Two cultivars of wheat (Marvdasht, Star) showed least allelopathic effect against H. spontaneum and L. rigidum.thus Chamran and Pishtaz have high allelopathic potential and after further research we can suggest these cultivars against H. spontaneum and L. rigidum.

In this study, the germination percentage, the start time of germination ( MT1), ,the final time of germination( MT2), seed viability index of Sorbus torminalis from different seed source during two years preservation in normal refrigerater conditions and comparison with the first year preservation were studied. The seed source namely Pasand, Sangedeh and Ashek in Mazandaran Province were selected for this research. The results showed that the effect of seed source was only significant on MT1 and MT2.The survey of seed preservation time has shown that the effect of seed preservation time was significant on germination percentage and MT2. The MT2 has also respectively increased to 28.2, 23.2 and 31.8 days for Pasand, Sangedeh, Ashek sources. The result indicated that trees with difference diameter have significant difference in seed germination , so that , trees in 40 cm diameter classes (35< x <45 ) have the most seed germination and trees with more than 55 cm diameter and less than 35 cm diameter have the lowest seed germination . Generally, from this examination, it can be deduced that, there are variation (between and within population) in the seed characteristics of Sorbus torminalis from populations. It’s also recommended that to collect seeds for gene bank, we should avoid from preserving them in refrigerator more than one year. Also, it can be deduced that seeds of tree with 36-55 diameter range more germination than other trees.

Iranian population with an Indo-European origin is one of the oldest populations in the world. Historical evidences suggest the close similarity in the origin of Iranian, European and north Indian population. However, there are few anthropological and genetic evidences on this subject. This study, which is the first report from Iran, was performed to investigate the genetic basis of Iranian population using a polymorphism in Cystathionine Beta synthase (CBS) gene known as 844ins68bp. The normal fragment is 174bp long (N) and the fragment containing the insertion is 242bp in length (I). Genotyping were done by using PCR standard methods. Ascertainment of Hardy- Weinberg equilibrium in the population was checked. Results indicated that 418 (87.08%) out of 480 individuals had a normal (N/N) genotype, 59 (12.29%) were heterozygote (N/I) and 3 (0.63%) had a mutated genotype (I/I). The total frequency of 844ins68bp allele was found to be 65 (6.8%) in 960 tested chromosomes which is comparable with the reported frequencies in Caucasians. Comparison of the genotype frequencies of this study to those of other populations revealed that southern Iranian population has a great similarity to other Caucasoid populations especially populations of south Italy, Spain and North America. It was also revealed that south Iranian population is highly far from East Asian and African populations. These results are in agreement with the previous results from studies of other genetic polymorphisms. Therefore، we conclude that despite the great admixture of Iranian population with the neighboring non-Caucasoid populations during the time, South Iranian population still shares a genetic background with other Caucasian populations.

Among prokaryotes, there are certain soil bacteria known as rhizobacteria which are very significant owing to their N2 fixation ability in legumes. The nucleotide sequence of the intergenic spacer (IGS) fragments residing between the 16S and 23S rRNA genes (16S-23S IGS) are not very conserved and thus are very useful in the grouping of rhizobial strains. In this research, 52 superior plant growth promoting rhizobacteria (PGPR) were grouped based on 16S-23S IGS PCR-RFLP and plasmid profiles. The results showed that the 16S- 23S IGS fragments of different rhizobial strains vary in size (600-1486 bp) and the number of IGS copies (1-3 copies). Based on the 16S-23S IGS PCR-RFLP profiles all 52 strains were located in 48 groups with 11 groups showing 70% intraspecies similarity. By using the above method, 77% of the strains (except 12 strains Bj 53, Bj 54; Rlv 27, Rlv 28, Rlv 23, Rlv 24; Rlp 16, Rlp 17; Sm 10, Sm 11, Sm 12 and Sm13) were separated into different groups. Therefore, this simple method which possesses minimal lab requirements is highly reliable and applicable for the genetic grouping of rhizobacteria in comparison to other molecular methods. The grouping based on the plasmid profile of rhizobial strains was in agreement (to some extent) with the results of the 16S-23S IGS PCR-RFLP method. For example, grouping of the Bj 53, Bj 54; Rlv 23, Rlv 24; Rlp 16, Rlp 17 and Sm 11, Sm 12 and Sm13 strains in both methods were completely similar and located in separate cluster groups.

Cell death in plants is a response to abiotic and biotic stresses. There are different signaling molecules, which downstream biochemical and molecular mechanisms in cell death. Salicylic acid is one of the most important signaling in plant response to biotic factors. Therefore, the effect of salicylic acid on the breakage of Poly (ADP-ribose) Polymerase (PARP), an enzyme participating in repairing DNA breaks, and DNA fragmentation on potato cell suspension was investigated. Results from western blotting shows that potato PAPR has a lower molecular weight despite of its homologue in animals. Also, potato PARP has similar epitopes with that of animals, because it is recognized by the animal anti-PARP. Also, it breaks after 12 hours of treatment with different concentrations of salicylic acid. Determination of DNA fragmentation was carried out by Diphenylalanin Method, Mono and Oligonucleosome determination ELISA kit and gel electrophoresis. The results show that DNA fragmentation after 6 hours of treatment with different concentrations of salicylic acid is lower than 12 and 18 hours. It is concluded that salicylic acid can proceed the Poly (ADP-ribose) Polymerase breakage in potato cell suspension followed by DNA fragmentation, which are markers of cell death.

Since mangrove forests are locating in intertidle zone, they had evolved specific adaptations to survive rough environmental conditions such as floods, hurricanes and hypersalinity. Undesirable conditions (like huge installations of the oil companies, overgrazing …) will accelerate destroying rate of the forests. In present study, isoenzymatic variation of 60 individuals of Avicennia marina determined. NTSYS software (pc-2.02e) with UPGMA program and Jaccard coefficient classified the genotypes. Then, these enzymatic groups of Avicennia marina lied on the pollution stresses. Qualitative studies of peroxidases showed individuals sensitive to pollutants in a short time. Among all the treatments NiCl2, and oil & gasoline complex and mixture treatments put the minimum and maximum effect, respectively. CdCl2, PbNo3 and HgSo4 didn't show constant behaviour during the times and individuals, as the time of the treatments increase, peroxidase activity will decrease following an initial increase.

Muridae is the most diverse of family among mammals. This family has seventeen subfamily, of which five are present in eastern Iran. In the order to investigate phylogenetic relationships among different genera of Muridae in the eastern Iran, thirteen genera from five subfamilies selected as ingroup and genus Allactaga belong to family Dipodidae as outgroup. Valuable characters were extracted from various references. Characters with specific polarity and transformation series in multistate characters were determined. Fifty cranial and dentary characters were used. In order to investigate polymorphism in the groups statistically determined number of individualsfrom each taxon were used and the results were recorded in character-taxon matrix. Choosing the most parsimonious cladograms, using Branch-bound and wagner’s optimizatation, resulted in finding six most parsimonious trees (MPCs) with the lenth 73. Strict consensus tree is chosen as resulted cladogram. Compatibility test of the characters led to the extention of thirteen homoplasis states in the characters and two clique diagrams with the largest length of 48 steps. The results show an unsolved node in the basic location for Calomicinae (BP=26). Arvicolinae, Gerbilinae, and Murinae (BP>96) clades monophyly and confirmation of Gerbilinae-M urinae. Clade containing Cricetinae-Arvicolinae is moderately confirmed (BP=48).

For ecological study and species identification of Gorgan Bay (Bandargaz Coast) polychaetes, some seasonal samplings were carried out at depth of 1, 2 and 3 meter in 2004. During the study, only three species polychaetes were obtained that Streblospio gynobranchiata species was observed for the first time in the Caspian Sea. The oneway ANOVA analysis results (P<0.05) showed that this invasive worm has been able to be the dominant species of area polychaetes at all depths and in all seasons. Study of population dynamics and biomass of polychaetes indicated that at all depths, the maximum and minimum biomass was in spring and winter, respectively. Also, the maximum density was obtained at one meter, two meter and three meter in spring, autumn and summer, respectively and minimum density was observed in winter at all depths. The maximum and minimum of Diversity and Evenness Index was obtained in spring and winter, respectively while it was vice versa for Dominant Index.

In this study, the cytogenetic characteristics of F1 progeny produced by artificial crossing between female grass carp and male big head carp Ctenopharyngodon idella ×♀ Hypophtalmichthys nobilis  ♂ were investigated using tissue-squashing of head kidney and giemsa staining method. A total 75 methaphase plates obtained from 15 individual hybrid fish (average weight 18 g) were investigated and different chromosomal characteristics such as chromosome no, NF, short and long arm length, centromic index, arm ratio, total length of chromosomes and its variations were determined and karyogram and ideogram of chromosomes were created using suitable samples. The final results showed that, in comparison with parents, the hybrids were triploid with 3n=72 and NF=132. The karyotype showed that these hybrids had 27 metacentric (m), 33 submetacentric (sm) and 12 acrocentric (a) chromosomes. The karyological parameters of triploid hybrids showed that the centromic index, arm ratio, relative length and length variation range of chromosomes were 19.20-46.80, 1.13-5.60, 7.53-2.54 and 1.27 -3.83 mm respectively. The total length of chromosomes in haploid series and NF were 50.51 mm. Longest and shortest chromosomes of triploid hybrids were a series of acrocentric and submetacentric respectively.

A survey on dite of Silurus glanis of Amirkelayeh wetland was investigated seasonally during of 2001-2. Fishes were caught using different gears such as gillnet, common haul sciene, cast net , dipnet and electroshoker. Caught fishes were biometry, age was determinated and then necropsy. Results on diet survey of 132 Silurus glanis showed that this fish was fed on 16 food types. Includings Tinca tinca and Amphipoda each with frequency of 36.3% and Blicca bjoerkna, Silurus glanis, Pungitius Platygaster, Perca fluviatilis , Rat , Bird , Water buge, Pleochoptera each with frequency of 2.2% show the highest and lowest values respectively . Also Proterorhinus marmoratus , Odonata , Carassius auratus gibelio, Frog, Cobitis taenia and water beetle had meadium frequency. Amirkelayeh wetland Silurus glanis were in age groups of 1+- 7+ (No any specieman was not at 6+ age group were catch), had average Total length of 50.6 cm (32.5 – 73 cm ), average weight of 944.2 gr ( 200 - 3000 gr) , average relative length gut of 0/71 (0/4 – 1/12 ), average Index of flulness of 292.5 (58.8 – 707.6) and average fullton’s condition factor of 670 (399.9 – 936.6 ). Meanwhile, vacuity index was zero. It is noteworthy that most of food types were in the stomach of Silurus glanis and intestine had digested foods or food wastes, that express the palatability of these foods and ability of fish selection according to prey size and use of vision and olfactory. According to results of present study, Silurus glanis is a carnivores, piscivores and shows cannibalistic deheviour. It’s diet change according to season , age and sex which is related to diversity of food types, but there is no significant differences between these values and relative length gut , Index of fullness and fullton’s condition factor.

Study of scales of 44 Aphanius ginaonis (Holly, 1929) specimens including 28 males and 16 females revealed that the index of relative length of scale in male and female specimens were 3.41 and 3.63 respectively and female scales were significantly larger than male scales (p<0.05). The index of relative width of scale was 3.795 in males and 3.82 in females indicating no significant differences. SEM studies showed presence of fine conical shape structure at the posterior end of the scales hence this scale is a fine ctenoid scale characterized by weak ctenii. The focus of the scale is clear and sharp located almost in the centre. Primary radii which originate from very near the focus divide the anterior position of the circuli into compartments. The radii are absent laterally and posterially. Originating far away from the focus, the secondary radii are seen. The scanning micrographs showed the presence of definite teeth-like structures on the anterior and lateral circuli. These are known as lepidont. The lepidonts have either conical blunt ending or bear a hook. At the posterior edge circuli end and round granules called tubercles are formed called tubercles. These are arranged in U shape fashion. At the posterior most end of the scale, the tubercles are replaced by conical projections of different size which are named ctenii. The skin covering the posterior field of scale is perforated by a number of pores of different diameter. These pores probably indicate the position of mucous cells situated in the epidermal layer. A distinct break in the circuli points towards the formation of an annulus is observed. The annuli indicate the fish age. Age determination and study of growth factors of this endemic and rare species will be useful in the population dynamic studies helping in its conservation.