مجله پژوهشهای گیاهی (زیست شناسی ایران)
سال بیست و هشتم شماره 1 (بهار 1394)

Diversity of plant species in a community changes in response to topographic factors such as altitude، aspect and slope. This study examined diversity changes in relation to topography in Dodangeh Forests، South of Sari، Iran. Plant species were collected in sampling units and the cover percentage of each species was estimated based on 400 m2 quadrats. There were 237 plant species in the area. Quadrats divided into 7 altitudinal classes، 3 slope and 8 aspect ones. Discriminant function analysis showed that altitude is the most effective factor to discriminate plant communities. The data were also subjected to analysis by specific diversity packages to characterize and obtain species diversity and evenness indices as well as species abundance models. The highest species diversity (Shannon H'' =1. 5-1. 6) and evenness (Smith & Wilson’s E= 0. 38-0. 42) were observed in the moderate classes of altitude. South، southeast and southwest facing slopes were more diverse than northwest one because of more available radiation and temperature. Gleason’s continuum view of plant communities can be considered for vegetation of the area.

Cultivation programming of medicinal plants is necessary for curing، limiting natural habitats، little reproduction and inexpedient cutting. The aim of this research to determine the most suitable treatment to overcoming seed dormancy and germination of Thymus transcaucasicus and Zataria moltiflora were conducted. Seeds of species were collected from their main habitats and treatments were tested including Gibberllic acid (for 100، 500 and 1000 ppm)، cold (10، 20 and 30 days)، Thio urea 1 Molar and KNO3. Seeds were sown in Petridishes for 15 days. This experiment was conducted in a completely randomized design with four replications. The results of analysis of variance showed that the effect of various treatments on Thymus transcaucasicus and Zataria moltiflora seeds germination percentage were highly significant different (p<0. 01). Treatments of gibberllic acid 100 PPM and Cold (10 and 20 days) have the highest seed germination percentage on Thymus transcaucasicus and KNO3 and Cold (10 and 20 days) on Zataria moltiflora seeds. The highest and lowest vigor index was in Thymus transcaucasicus، gibberllic acid 100 PPM (16. 2) and KNO3 (2. 4)، in Zataria moltiflora Thio urea 1 Molar (10. 9) and Cold 20 days (1. 37).

Saline land area is increasing and salinity is one of the most important challenges in the world. The investigations have showed that salinity decrease seed germination and limit plant growth. Arachis hypogaea is an annual legume that belongs to fabaceae family and because of high oil quality and protein content is cultivated in 109 countries. In order to study the effect of different levels of salinity on germination of four genotype of Arachis hypogaea (Local cultivar، ICGV95148، ICGV96177 and ICGV03060) an experiment was conducted using four levels of NaCl (0، 50، 100 and 150 mM) in plant physiology laboratory، University of Guilan. The seed germination percentage and speed were examined at fifth، seven، ninth، eleventh and thirteenth days. On day thirteenth، length of radicle and plumule and their ratios، fresh and dry weight of seedling and seed vigor determined. Results showed that salinity and cultivar has a significant effect on all of the examined characteristics except for dry seedling weight and length of radicle. Moreover the results indicated that the interaction effect of cultivar and salinity had a significant effect on germination percent and speed، length of radicle and radical length /plumule، Total of length of radicle and plumule، seedling fresh weight and seed vigor. Local cultivar was found the most tolerant cultivars to salinity.

Antibiotic resistance has contrived use of medicinal plants with less side effects instead of common drugs. The present study was done to investigate antibacterial effects of garlic ethanolic extract against antibiotic resistant Staphylococcus aureus strains isolated from nasopharyngeal samples. Extraction was done using vacuum distillation (rotary). A total of 17 Staphylococcal strains were isolated from nasopharyngeal swabs of in- and outpatients in Ali-Ebne-Abitaleb hospital (zabol). Antibiotic resistance was determined using Kirby Bauer method and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of garlic extract was determined using micro-broth dilution method. Antibiotic resistance of the isolates was as follow: Penicillin (88. 2%)، Erythromycin (82. 4%)، Cefoxitin (82. 4%)، Trimethoprim (70. 6%)، Ampicillin (70. 0%)، Ceftazidime (29. 4%)، Tetracycline (23. 4%)، Ceftriaxone (23. 5%)، and Amikacin (5. 9%). The MIC and MBC for garlic extract were 1. 25 and 5 mg/ml resoectively. Garlic extract has high anti staphylococcal effects compared with common antibiotics and could be used as a benefit medicinal plant. However، it is suggest more studies to ensure its medical effects before wide medical usage.

Titanium is not essential micro element but it has reported that it is useful for better growth and improvement of metabolic processes in plants. In this study، the effect of titanium on growth rate and synthesis of pigments، rate of photosynthesis and respiration of algae were measured. For this purpose، the different concentrations of 100، 150 and 200 µM of Ti+3 were applied on the D. salina. Based on results in all treatments on listed parameters no significant differences were observed but in the presence of EDTA were increased. Effect of pH was similar with results of effect of titanium in the presence of EDTA. Photosynthesis and respiration in the long-time treatment of 150 µM of Ti+3 decreased over 24 hours. In short-time treatment photosynthesis increased by the increase of Titanium concentration in the medium by 150 µM. Higher concentration had negative effect. Respiration in 50 µM of Ti+3 increased campared to the other concentrations and it was decreased with increasing of Ti+3 concentrations by 200 µM.

This study was carried out to investigate the relationship between vegetation and environmental factors of Quercus petraea habitat in the district No. 8 of Asalem forests، Guilan. Data were selectively collected in 30 sampling plots of 50 m × 50 m. In each plot، diameter at breast height (dbh) of trees ≥ 10 cm were measured considering the tree species. Herbaceous species data were taken using Whittaker’s nested plot sampling، the species coverage were estimated using Domin criterion، and types of the species were identified in each plot. In addition، the most important topographical factors were recorded in each plot. Soil samples were taken from depths 0 to 20 cm in each plot center and to characterize ecological species groups، TIWNSPAN method was used. Also، Canonical Correspondence Analysis (CCA) was applied to study relationship between environmental factors and vegetation composition on plot level. Results indicated that there are four ecological groups in the studied area; and that elevation، aspect، bulk density، gravel percent، organic carbon، organic matter and total nitrogen were the most important factors in determining the ecological groups.

Environmental pollution with heavy metals is increasing and Lead is one of the most important pollutants of the environment. In this research Solanum melongena was selected and studied on ovule developmental stages of Eggplant، which is one of the main agricultural plants in Asia and Africa continents. For this aim، this project was set as CRD design with 4 treatments including different concentrations of lead acetate 0mM، 3mM، 6mM and 9mM، were spread on the experimental plants. Then the flowers were collected in different developmental stages and fixed in FAA then subjected for developmental studies and studied with photomicroscope. Results of microscopically studies showed that Lead treatment could influence developmental staged of pollen grains، so that the increase of lead concentration increases abnormalities in plants. Some of these abnormalities in plants that treated by Lead acetate such as، accumulation of dark particles، vacuolated pollen grain، change in natural shape of pollen grains، formation of tetrads and pollen wall were shown. Decrease of fertility and viability in pollen grains was also seen in plant treated with Lead acetate.

In order to study the anatomy and ontogeny of generative meristem in Ziziphus jujuba generative meristem and young buds (tiny buds to mature buds)، in different developmental stages، were removed، fixded in FAA embedded in paraffin and sliced at 7-10 µm. staining was carried out with Hematoylin – Eosin. The generative meristems and young buds were studied with light microscope after staining. Results showed that vegetative meristems developed to generative meristem and different components of flower were formed. Anther primordium and carpel primordium and petals were formed from sporangiare meristem. sepals were formed from initial ring. As well as carbohydrate contents and antioxidants enzymes activities in different seasonal conditions (spring and summer 1390) in two cities (Behshahr، Mazandaran; Galikesh، Golestan) measured. As seasonal changes، proteins levels and peroxydase activity increased in two cities، while catalase and ascorbate peroxydase activities reduced. Soluble and insoluble carbohydrates levels don’t have any significant difference. Proteins levels and peroxydase activity were more in Behshar and catalase activity in Galikesh respectively.

In order to investigate the influence of soil factors on plant diversity and ecological groups in the Northern Khorasan Province، 220 hectares of Joezak-Darkesh forest was studied. At first، 55 sample plots 20 m x 20 m were selected for vegetation determination. Then، 18 samples from superficial layer of soil (depths of 0-10، 10-20 and 20-30 cm) were taken and electric conductivity، pH، organic matter (OC)، total nitrogen، available phosphorus، soil texture، K and C: N ratio measured. The first ecological species groups using two-way analysis method of TWINSPAN was conducted and the study area to five different ecological units Cotoneaster integeryma (A)، Fraxinus excelsior (B)، Prunus divaricata (C)، Carpinus betulus (D) and Acer laetum (E) was divided. Analysis of ecological species groups showed that different groups had significant difference (p <0. 05) on Simpson diversity. Duncan’s test revealed that the highest species diversity allocated to E، B and D ecological groups، respectively. This is while that، in terms of other biodiversity indices، no significant differences was detected among the ecological. Pearson regression Analysis displayed that increased of pH in 3rd depth of soil had negative effect on the Simpson diversity index and Margalef species richness. The amount of OC and K in first soil depth had positive effect on the Simpson diversity. Other soil characteristics did not affect the diversity indices. From this research it can be deduced that among the affecting factors، OC and K of first soil depth separated five-fold ecological groups in the investigated site.

In this study، the influence of foliar application of Na2SeO3 (1. 5، 10 and 100 mg l-1) on some physiological parameters was investigated in two cultivars of spring wheat. Results indicated that application of selenium (Se) increased biomass accumulation in Zagros and Chamran cultivars. The highest content of Se in grain (1. 01 mg kg-1 DW in Zagros and 0. 465 mg kg-1 DW in Chamran) was detected under application of 10 mg Se l-1. Concentrations of malondoialdehyde (MDA) and hydrogen peroxide (H2O2) remained unchanged in Se-supplemented plants obviously because of an efficient scavenging following significant enhancement of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity. These results suggest that foliar applications at 10 mg Se l-1 alleviate oxidative stress and cause a significantly higher growth rate in both cultivars. In addition، our results indicated that Se can be used for biofortification of wheat grains thus، for increasing dietary Se intake in human.

The effect of forest management was investigated on natural forest stands at district 7- Shenrood (Siahkal). Parcel 2 of the given district (81 ha) was selected as an unmanaged region while parcels 3 and 4 (in total 80 ha) were considered as managed ones. Inventory was based on a systematic method. However، the starting sampling point was based on a randomized method. The dimensions of inventory were 200 × 150 m with circular plots 0. 1 ha. At each sample plot، we measured the kind of species، diameter at breast height، the height of two witness trees and the quality condition of trees. We also recorded all tree regenerations with diameter at breast less than 12. 5 cm. The obtain results showed that there are no significant differences between the average of basal area، volume per hectare and the degree of tree quality in managed and unmanaged parcels. There were also no significant differences between numbers and standing volume per hectare، mean Lorry’s height and regeneration in the managed and unmanaged forest stands at 0. 05 confidence levels. The number of beech species was respectively obtained 83. 87% and 97. 15% in managed and unmanaged parcels. Management practices in forest stands caused an important change from the gross beech forest stands to the pure beech forest stands and it also increased regeneration abundance of beech. The result also showed that the range of the altitudes is suitable for establishment of beech species.

Edible pistachio (Pistacia vera L.) is an important species of Pistacia genus and Anacardiaceae family. The morphological and anatomical traits of the male flower، anther and the pollen grain developmental stages of pistachio were investigated by cytohistological methods. The results showed that the male flowers are in grappe inflorescence and have 4-7 stamens with large anthers، 2-3 sepals and 0-1 bracktes. Two sacks of each side (theca) of the anther are completely separated from each other and are deeply dehiscent in length at the connective area. The cytoplasm division، during the microspore mother cell meiosis، occurs simultaneousely. The attained tetrad is tetrahedral and the tapetum layer is glandular. The number of the layers of the middle layer is three or more. These are remarkably viable and at the end of the maturation، degenerate with tapetum or even at the time of anther dehiscence. The mechanical layer has fibrous ornamentation and the epidermis is settled on it. The pollen grains are circular with 3-5 germinative pores and are brochate in surface.

Drought stress is one of the most important factors limiting the survival and growth of plants in the Drought stress is one of the most important factors limiting the survival and growth of plants in the different habitats of Iran. Detailed knowledge about the ecophysiological responses of native plants to drought stress could contribute to the success of re-vegetation programs. Different accessions of two perennial chamomiles، Anthemis tinctoria and Tripleurospermum servanes were subjected to four drought treatments، i. e. well-watered (control)، mild drought stress (75% field capacity)، moderate drought stress (55% field capacity)، and sever drought stress (35% field capacity). Osmotic solutes (proline and soluble sugars)، Relative water content (RWC)، antioxidant enzymes (peroxidase and polyphenoloxidase) and pigments were investigated. Drought stress significantly increased accumulations of osmotic solutes، but decreased relative water content، total proteins content، dry matter percentage in the studied species. In both species the chlorophyll a and total chlorophyll contents did not changed in drought stresses، however the cartenoids content and the ratio of cartenoids to total chlorophylls significantly increased. Although the peroxidase activity، as an antioxidant enzyme، of all three accessions of T. servanes increased in sever drought stress، but in two accessions (of three accessions) A. tinctoria considerably decreased. These findings suggested that the A. tinctoria and T. servanes showed a moderate tolerance to drought، although in both species some accessions had higher tolerance to sever drought stress than the other accessions due to higher capacities of osmotic adjustment.

In this research، seeds and seedlings of two alfalfa cultivars (Yazdi and Hamedani) were inoculated singly or in combination by strains of Sinorhizobium and Bacillus species and grown at 2 levels (0 and 100 mM NaCl) of salinity. Rhizobium strains were isolated from nodules of alfalfa plants and Bacillus was isolated from rhizosphere soils of fields in Isfahan-Dolatabad. Salt tolerant strains were detected by drop plate method on YMA and PVK culture medium containing 100 mM NaCl. Salinity increased electrolyte leakage and reduced fresh and dry weight of plants، chlorophyll a، b content، in both cultivars. Cultivar ''Hamedani'' was more sensitive to salinity compared to cultivar ''Yazdi''. Inoculation with Sinorhizobium and Bacillus improved plants growth، chlorophyll content and membrane stability under both non-saline and saline conditions compared with the non-inoculated control plants. Two bacterial strains acted synergistically، so that، co-inoculation was often more effective than single inoculation with Rhizobium or Bacillus. Our results suggest that inoculation by strains of these two bacterial species could help to alleviate salinity stress in alfalfa plant.

Study of the Phenology is the most important ecological issues and it can be a foundation for Resource Management. Phenology Recognition of different rangelands species in relation of grazing management and sustainable utilization of rangelands forage is an important issues. Without knowing Phenology of different rangelands species is not possible to determine the grazing season and grazing management and livestock. Therefore in order to determine of Entering livestock time and on time exit of the rangeland، phenology of Atriplex verrucifera as dominant species In the semi-steppe rangelands of Uromieh Tzkhrab and Soil moisture condition Was studied. The interpretation of Phonological stages was done by climate data. Result showed that the beginning of July to Second half of June and the end September to late October is the best time to start grazing of the Atriplex verrucifera species. Also Soil moisture result showed livestock entrance to rangeland in the late May will not cause a problem.

Heavy metal pollution is one of the most important ecological problems in the whole world. According to the environmental protection agency (EPA)، Pb is the most common heavy metal contaminant in the environment. In this study the effects of Pb stress (0، 120، 240، 500، 1000 μM Pb) on 7 days seedlings of Medicago sativa L. were investigated in hydroponic culture. The our results indicated Pb accumulation in roots and aerial parts and an increasing trend in total biomass was observed with increas of Pb concentration in medium which reduced later. Compared with control seedlings، increase in the contents of MDA and H2O2 were observed in those the seedlings under Pb stress. Moreover، increase in total flavonoids content، and peroxidase activity in roots and shoots of the treated seedlings were observed under Pb stress. Content of total phenolics decreased in roots and increased in shoots comparing to than the control.

Soil salinity is one of the most important factors reducing the growth and yield of plants worldwide and determining plant distribution. Antioxidant systems play a crucial role in salt tolerance of plants. In this investigation، the effect of salt stress and its interaction with ascorbic acid on production of H2O2، malondialdehyde، membrane stability and root activities of catalase and peroxidase in Lepidium sativum L. were investigated. The experiment was conducted in a completely randomized design with four replications. Plants were harvested one week after starting treatments. The results showed that salinity increased the amount of H2O2 and malondialdehyde in leaves and roots، and catalase and peroxidase enzymes activities of the roots. Salinity decreased fresh weight of the shoots and roots، and membrane stability of the leaves. This reports shows that exogenous ascorbic acid can alleviate salinity stress effects on plants. As a whole، these data suggest that the ascorbic acid increased the tolerance of Lepidium sativum under salinity stress by overcoming the oxidative effects.

In the present study، the effects of indole acetic acid (IAA) on certain physiological and biochemical parameters in Glycine max (L.) Merr under aluminum chloride (AlCl3) stress were studied. Seeds were sterilized and cultured in petri-dishes. Six days old seedlings were transferred to pots، and then they were irrigated with Hoagland solution in a growth chamber (with 16 h light period per 24 h، with day / night temperatures of 25/18 ºC respectively). Fourteen days old plants were treated with different concentrations of AlCl3 (0، 50، 100، 200 and 300 µM) and IAA (0، 50 and 100 µM). Plants were harvested 15 days after treatment. With increasing of aluminum concentration، NAR، RLGR، RWC، protein and soluble sugars contents decreased، however، SLA and peroxidase and catalase activities increased. With addition of IAA to culture solutions containing aluminum، the plants showed further decrease in the amount of soluble sugars، but the other parameters were adjusted. With increasing of aluminum concentration to culture solutions with and without IAA unsoluble sugars increased. Exogenous indoleacetic acid counteracted the deleteriots effects of Al3+ stress and helped plants to grow successfully under these adverse unfavorable conditions.

The current investigation concerns the flora of a political boundary mountainous area of Arzaneh، 70 km northwest of Taybad، Khorassan-e Razavi province. A total of 255 plant species belonging to 51 families and 186 genera were identified during 2011 and 2012. Hemicryptophytes (37. 5%)، therophytes (32. 8%)، geophytes (14. 8%)، chamaephytes (9. 8%) and phanerophytes (4. 7%) constitute the life form spectrum of the study area. From a chorological point of view، Irano-Turanian elements were dominant chorotypes (55. 9%) and the rest of plants were related to one، two، three or various other phytogeographical regions. The area comprises 31 Iranian endemic species. According to IUCN conservation categories، seven species of the area were classified as vulnerable (VU) and lower risk (LR) in Iranian red data list.

In this study، effect of different concentrations of AgNO3 (for 4 hours treatment) and CuSO4 (for 16 hours treatment) elicitors were investigated on gene expression of FNS I and anti oxidant system in 21-day Cuminum cyminum seedlings. Semi-quantitative study of FNS I gene expression was shown a significant increase at 25 and 50 µM Ag concentrations rather than the control sample which decreased by the increase elicitor concentration up to 100 µM. On the other hand، by the increase elicitor concentrations، total flavonoid and anthocyanin contents and activity of some antioxidant enzyme as well as total protein content significantly increased. The gene expression were significantly elevated in treated seedlings by Cu elicitor at 4 and 8 µM treatments and its expression completely inhibited at 16 µM concentration. In this condition، total flavonoid and anthocyanin contents showed a similar trend and their contents were significantly reduced at 16 µM compared to the control sample. In contrast، the activity of antioxidant enzymes including catalase and superoxide dismutase، increased by the increase elicitor concentration، while total protein content drastically decreased. Based on the results، it deduced the increase FNS I gene expression and flavonoid and anthocyanin contents، were resulting in oxidative stress following absorption of these elicitors and activation of plant antioxidants system.