Journal of Plant Research
Year:2015 | Volume:28 | Issue:2|Papers Count:20

CentaureaL. with about 700 species in the world and 70 species in Iran is the largest genus in the family Asteraceae. Centaurea species are used for the treatment of various ailments in the popular medicine in some countries. The aim of the present study was to investigate total phenol and flavonoid contents, antioxidant potency and antibacterial activities of the methanolic extracts from capitulum and aerial parts of three Centaurea species, namely C. imperialis, C. iransharii and C. glastifolia. Total phenolic and flavonoid contents were evaluated by Folin-Ciocalteu and aluminum chloride methods, respectively. Antioxidant activity was evaluated by DPPH radical scavenging assay. In addition, antibacterial activity of the extracts was studied by disc diffusion method. Results from the study showed that total phenol content in the extracts were found to a range between 32.92 and 73 mg gallic acid/g extract and total flavonoid content varied from 4.45 to 5.30 mg quercetin /g extract. A significant antioxidant capacity was found in all studied extracts and aerial part extract of C. iransharii showed the highest antioxidant activity (IC50=0.11 mg/ml). In addition, the studied species represented strong antimicrobial activity against Gram positive bacteria.

Sorbus aucopariais an important forest tree from Sorbus genus in Rosaceae family. It is an important medicinal, industrial and ornamental plant. Sorbus aucoparia is potentially useful for reforestation in high altitudes. This species is one of the endangered species of the Northern forests of Iran. Micropropagation of the adult trees by bud culture helps conserve this valuable species. In this study, proliferation of Sorbus aucopariain photoautotrophic (artificial CO2 nutrition) and semi photoautotrophic (by the use of available CO2 in the space around the dishes in growth chamber) conditions was performed. Shoots of tissue cultured plantlets from mature trees, were used as explants. The explants were cultured on DKW media supplemented with and without sucrose with agar or vermiculite for six weeks, in Magenta (G7) containers. Gas exchange rate of culture containers under photoautotrophic and semi photoautotrophic conditions were measured. The results showed that shoot height, shoot and bud numbers, dry weight, leaf number, leaf area, chlorophyll quantity, rooting percentage and leaf greenness under photoautotrophic condition have significant differences with semi-photoautotrophic condition. These findings suggested that, photoautotrophic technique is a more applicable method than semi-photoautotrophic technique for micro propagation of Sorbus aucoparia.

Artemisia is a widely distributed genus from Asteraceae. Some species of the genus despite having allelopathic effects, provide favorable microclimatic conditions for the establishment of range plants under its canopy. Therefor, study of nurse plant, s allelopathic effect such as Artemisia korassanica Krasch. on understory like Bromus kopetdaghensis Drobov. is necessary. In this research, sampling was carried out in a range site in Baharkish, Ghochan by systemic randomized method at four different stages of the growth and development of shoot and root of A. khorassanica. we studied effect of water extraction on level (3% W/ V) of shoot and root of A. khorassanica on dry weight, chlorophyll content and soluble carbohydrate content of the shoot and root in B. kopetdaghensis seedling, and also we studied the amount of phenolic compounds and their changes during the different stages of growth and development in A. khorassanica. Results indicated that shoot extract of Artemisia had stronger inhibitory effect than the root extract and caused significant decrease on thedry weight and growth of leaf and root in B. kopetdaghensis. Total phenolics content in shoot extract as well as its inhibitor effect decreased gradually from the beginning towards the end of growth season. According to the results of the present research, it seems that the most suitable time for planting of Bromus seeds under the Artemisia canopies is in October, when Artemisia plants are in the seed rippening stage.

The effect of different cytokinins on micropropagation of lavandula vera were investigated. Two nodal explants from greenhouse plant were cultured in MS medium supplemented with benzyl aminopurine (BAP), 2-isopentenyl adenine (2ip), Kinetin (Kin) solely or in combination. Results indicated that shoot proliferation depended on type and concentration of hormone. The highest number of nods and new shoots per explants and stem length was produced in the medium with BAP (2 mgl-1). Growth of internodes was significantly increased in the medium with Kin and 2ip (1 mgl-1).In the subculture media, the highest number of nodes and new shoots per explants was obtained in the medium with BAP (1 mgl-1). Maximum of internode length was achieved in the medium with Kin (2 mgl-1). In vitro shoots were rooted in vitro or ex vitro. By using in vitro method, microshoots were cultured in the media supplemented with different concentration of indole butyric acid (IBA) and Kin. In ex vitro method, the base of micro shoots was treated with IBA (300 mgl-1). The highest number of roots as well as length of roots was obtained in ex vitro rooting method.

The study forest habitat is located in 24 km east and north-east of Ardabil, and 9 km south eastern of Namin on the area about 913 ha. From this area, 252 ha is forest habitat and study of flora was conducted only at these areas. Forty three families, 108 genera and 128 species were identified. Rosaceae, Poaceae, Fabaceae, Apiaceae and Asteraceae families have the highest frequency in these areas. Hemicryptophytes with 47% (61 species) and Phanerophytes with 22% (28 species) are with the highest frequency life forms at the study area. Choryotypes identification show that most of the species belongs to Euro- Siberian (Hyrcanian) and Irano-Turanean regions.

Mentha pulegium L. is a permanent and grassy plant which has an almostly cylindrical shape. Mentha pulegium L. is from mint family and it is used as a condiment and medicinal herb. Because large areas of Iran are covered by saline soils, study of the effect of salinity on plant development, including Mentha pulegium L. is important. In Iran this plant is native to the north of the country. In this study, samples were treated with concentrations 20, 50, 65, 80 and 95 mM NaCl, then buds and young flowers at different stages of development were removed and fixed in FAA, and next they were embedded in paraffin and sliced at 7-10 μm. Staining was carried out with Hematoxylin –Eosin. Now the best slices were studied by light microscope. The results showed that ovary is created from cell divisions of the middle and deep parts of the sporangiare meristem. In Mentha pulegium L. development of the ovary is postponed in comparison with stamen. Ovules are anatropous. Megaspore mother cell produces embryonic sac on the mature ovule by its division. Investigating the anatomical generative meristem in Mentha pulegium L., showed accelerated growth of stamen primordia proportional to carpel primordium in the 20 mM treatment, simultaneous growth of the carpel and stamen primordia in the 50 mM treatment, and delayed initiation of petal and carpel primordia in the 65, 80 and 95 mM treatments respectively.

Heavy metals are defined as the group of elements with an atomic density greater than 5 g/cm3. Existence of heavy metals can affect growth and physiology of plants. Chromium is a transition metal located in the group VI-B of the periodic table that is the seventh most abundant element on the earth and is known as a toxic metal for microorganisms and plants. This study was performed in a complementary randomized design with six levels of chromium (0, 10, 25, 50, 75 and 100 mg/kg) and four replications, in the research greenhouse of the Kharazmi University. The results indicated that increasing of chromium concentration significantly decreased the dry and fresh weight of the shoots and roots. Moreover, Chla, Chl b, Chl (a+b) and carotenoids contents, growth ratio and RWC significantly decreased in the whole treated plants, whereas flavonoids, anthocyanin and proline contents increased.

Salicylic acid (SA), a plant phenolic compound is considered as a plant growth regulator and its role in the defense mechanisms against biotic and abiotic stresses has been well characterized. This experiment was conducted to investigate the impact of SA on growth, physiology and biochemical parameters ofTriticum aestivum grown under salt stress. For this purpose, Triticum aestivum L (Shiraz and Star cultivars) seeds were soaked in SA (0, 0.5 and 1 mM) and then salinity was applied by NaCl (0, 100 and 200 mM). FW (fresh wight), photosynthetic pigment and total protein contents decreased sharply with increasing stress levels. Prolin, MDA and H2O2 content increased significantly under salt stress. However, seeds pretreated with salicylic acid along with the salinity levels showed enhancement in growth parameters, photosynthetic pigments, and total protein content, while proline, MDA and H2O2 levels decreased. The results showed that deleterious effects of salinity in Triticum aestivum plants were significantly encountered by the pretreatment with salicylic acid. It is concluded that salicylic acid could ameliorates the negative effects of salinity in Triticum aestivum cultivars.

Changes in species diversity may result from relationship between species, environmental and human factors. In this study, the role of environmental and human factors (grazing and land use changes) was investigated on the species diversity changes in pastures around the Veshteh village located in middle Taleghan region. Five plant types were identified in this region that one of them was from abandoned agricultural lands, another one was near the watering point with intensive grazing and 3 other types include average, light and without grazing types. Sampling was done using 4 transects with 150 meters length and 15 plots of 1 m2 were placed 10 meters apart from each other along each transect. In the beginning and end of each transect a profile excavated and soil samples from 0- 30 cm depth were taken. After data collection, heterogeneity, uniformity and species richness indices were calculated using Past and Ecological methodology. Principle component analysis also used to determine the most important factors affecting species richness. Results of principle component analysis showed that texture, organic matter, nitrogen, height, electrical conductivity and PH affect the diversity changes in the region. Besides environmental factors, effect of human factors such as grazing and land use conversion was investigated on species diversity but these factors didn’t recognized effective on diversity of this region, but despite the impact of these factors, the diversity indices values were high. Rank-abundance model also was used to illustrate the distribution pattern of species in studied types. Results indicate that all types had log normal distribution and represent relatively stable plant communities with number of species that their average abundance was very high.

Plant tissue culture techniques are a useful tool to increase the genetic diversity, crop production and production of plants virus free. The purpose of this study was reached to a useful method for callus induction. The experiment was set up based on factorial experiment and completely randomized design (CRD) with 4 replications. The effect of different concentrations of 2, 4- D (0, 1, 2, 4 mg/l), Kin (0.25 mg/l) plant growth regulators and two explants (leaf and internode) were evaluated on callus induction. Results of analysis of variance showed that there was significant difference between two types of explants (leaf and internode) for diameter and fresh weight and percentage of callus induction traits, also different concentrations of 2, 4- D and Kinetin were significant for all traits. The interaction of PGR*explant was significant for all traits. The results of means comparison showed that the highest percentage of callus induction (75%) was in leaf explants at a concentration of 2 mg/l (2, 4- D) and for internode explant (87.5%) at 4 mg/l of 2, 4- D. Diameter and fresh weight of callus were maximum in leaf explant (5.60 mm and 0.55 g) and in internode explant (9.13 mm and 0.92 g) at 2 mg/l concentration of 2, 4- D.

In order to study of the effects of biofertilizers on growth indices and contribution of dry matter remobilization in wheat grain yield, a factorial experiment was conducted based on randomized complete block design with three replications. Factors were: nitrogen application time at three levels, (1/3 planting, 1/3 tillering and stem elongation, 1/3 before flowering), (1/4 planting, 1/2 tillering and stem elongation stages, 1/4 before flowering) and (1/4 planting, 1/4 emergence, 1/4 stem elongation, 1/4 flowering) as N1, N2 and N3 respectively. Seed inoculation treatments with PGPR containing control (without inoculation) seed inoculation with Azotobacter chrocoococum strain 5, Psedomunas strain 41 and 186. Maximum of dry matter remobilization per plant was obtained in nitrogen application time as N1 without seed inoculation and the least was obtained in nitrogen application as N3 and seed inoculation with Azotobacter. Grain yield per plant, number of grains per spike, hundred seed weight, plant height, root weight and protein content (%) increased at nitrogen application as N1 and seed inoculation with PGPR. Dry matter accumulation increased slowly at all treatment combinations until 40 days after sowing (DAF), then increased rapidly till 70 (DAF). Then it decreased till harvest time due to aging of leaves. So, it can be suggested that in order to increase grain yield and other growth indices, nitrogen should be applied as N1 in combination with seed inoculation with Azotobacter.

In this research, the effects of aeration and agitation of culture vessel onSpirulina biomass production were studied in five various culture media.Spirulina was cultivated in Zarrouk, Jourdan, F2, Schlosser, and seawater salt culture media. In the cultivation system with aeration, mixing was performed with air flow of 0.2 vvm, and in cultivation system with agitation of culture vessel, shaking was performed continiously at 150 rpm using a shaker. Temperature and lighting were kept constant in all cultures and at 26±2ºC and 40 mE m-2s-1, respectively. Spirulina was grown in all cultures, reached to highest cell concentrations of 4.0 g L-1 by agitation system and 3.68 g L-1 by aeration system. In agitation, highest level of biomass production obtained in Zarrouk culture medium equal to 4.0 g L-1 wheares lowest level was obtained in seawater salt culture medium equal to 2.49 g L-1. In aeration, the highest level of biomass production of 3.69 g L-1 was obtained in seawater salt culture medium wheares lowest of 2.3 g L-1 was obtained in F2 culture medium. The pH increased continuously up to 10.9 during cultivation in agitation system, but in the aeration system, the pH increase up to the 7th cultivation day and then stopped at 10.1. In the seawater salt culture medium, biomass production in the aeration system was higher than in the agitation of culture vessel. The finding of this study indicate that stress has high effects on Spirulina growth and biomass production, and by reducing the stress, the yield of Spirulina production can be increased for commercial purposes.

Anthocyanins are a subclass of flavonoids and are responsible for red, purple, and blue colors of many flowers, fruits and vegetables. The stability of anthocyanin color can be improved by copigmentation. Copigments are colorless substances which can form a colored cluster with colorless forms of anthocyanins. The color changes in fruits, vegetables and flowers may be caused by these reactions between anthocyanins and various organic compounds present in higher plants. In this study copigmentation of anthocyanin in red onion was investigated with four copigments: tannic acid, coumaric acid, caffeic acid, and benzoic acid in five levels of copigment concentrations: 0, 120, 240, 480, 960 (mg/l). The effect of the copigmentation process on copigment concentration and the effect of sugar on the process were examined. The copigmentation of anthocyanin resulted in increase in both hyperchromic effect and bathochoromic shifts. In this study, tannic acid had the highest hyperchromic effect (0.093) and benzoic acid had the lowest one (0.051). Copigments had the highest effects in their highest concentrations. Low concentration of sucrose (10%) improved the stability of anthocyanin-copigment complex. In this study, tannic acid was the predominant among the other copigments.

Dorema ammoniacum is a native medicinal plant in Iran, which due to ruinous harvesting practices and its natural habitats are destroyed in the country, the species is getting endangered. Somatic embryogenesis is considered as useful method for propagation of plants. In the present study induction of embryogenic callus from zygotic embryo of this plant were investigated using MS and 1/2 MS basal media and also the different concentrations of NAA and BA hormones. It was observed that MS medium containing 1 mg/l NAA with 0.5 mg/l BA hormones was the best medium for callus induction and maximum number of somatic embryos production. Furthermore, MS basal medium compared to ½ MS basal medium showed a better result, not only in the callus formation but also in the somatic embryogenesis. No embryogenesis was observed after sub-culturing of non-embryogenic calluses in hormone-free MS basal medium. When embryos were transferred to media without growth regulators, whole plantlets were regenerated.

Here and for the first time, this paper reports sex determination of cycad (Cycas revoluta Thunb.) befor maturity and cone formation. Sex determination in cycad is possible only after maturity and cone formation. At least, the 10 to 12 years in optimal conditions is needed for cycad to reach maturity. In this research, two-year old male and female off-shoots of cycad were separated from the adult male and female plants and were treated in natural conditions, uniformly. Morphological characteristics of male and female plants were visually compared. Anatomical features were studied on the sections prepared from primary leaf rachis, leaflet and root by light microscope. According to the Discriminate Analysis (DA) method, differences between morphological characteristics of male and female plants such as leaf rachis diameter, leaflets width, leaflets distance on the rachis, leaflets angle on the rachis, roots diameter and length, were significant. The arrangement of leaves in one third of middle part was bipinnate with opposite leaflets and bipinnate with alternate leaflets in male and female plants, respectively. New leaflet initiates to forms befor and after completely formation of previous leaflet in female and male plants, respectively. Anatomical studies showed that the difference between the lengths of lower stomata in male and female leaflets were significant. Type of stoma in cycad leaf is actinocytic.

In order to rehabilitate the degraded mountainous forests in village's vicinity with fast-growing species, one experimental sites was selected in east, northern of Iran. The selected sites was located in Farim (Sangdeh) in Mazandaran provinces. eleven seedlings of different species and clones of Poplar and Paulownia were planted in 5x5 groups in frame of Randomized Complete Block Design (RCBD) with 3 replications. Results of survival percetage and wood production after 5 years of study showed that some of species and poplar clones such as, Populus euramerican 488, Populus. trichocarpa Torr, Populus euramericana 561.41., Populus tremula L., and Populus euramericana triplo., were the most promising species which can be introduced for rehabilitation and wood production in the study area. Paulownia was not successful and it is not suitable in the higher elevations. This species need to more study in future.

In the present study, the effects of two types of extraction methods: traditional and microwave-assisted extraction (MAE) on antioxidant activity of Urtica dioica L. was investigated. Water, methanol and ethanol extracts of leaf and stem of Urtica dioica L. were obtained from both traditional and MAE methods and evaluated for their radical scavenging capacity (RSC) by high performance liquid chromatography (HPLC) -separated antioxidants with the 2, 2‘-diphenyl-1-picrylhydrazyl radicals (DPPH). The antioxidant activities of all the extracts were determined by high performance liquid chromatography at 517 nm using 1, 1-diphenyl-2-picrylhydrazyl free radical (DPPH). It was determined that antioxidant activity of leaf and stem (ethanol extracts) of Urtica dioica L. by MAE method was higher compared to traditional method, however, was not significantly different (p>0.05). In conclusion, HPLC-DPPH assay did not show significant difference between MAE and traditional methods in antioxidant activity of leaf and stem of Urtica dioica L.

Salvia L. is one of the most important members of the Lamiaceae family. Several species of this genus have many pharmaceutical applications. A very limited number of investigations have been reported for fatty acid and phytosterol profiles in this genus. This study was accomplished in order to quantify of oil content and to determinate fatty acid and phytosterol profiles of the seeds from three Salvia species of Iran. Seed oils were extracted using n-hexane as solvent in a Soxhlet apparatus. Free fatty acids were prepared by the saponification of the oils and after methylation were analyzed by GC method. Conjugated and free sterols were extracted from the unsaponifcable fraction of the seed oils and after derivatization were analyzed by GC. Five major fatty acids including a-linolenic (41.84±0.51-49.28±2.28%), linoleic (20.63±0.03-30.25±0.36%), oleic (14.02±0.72-19.94±0.16%), stearic (2.13±0.01-2.41±0.06%) and palmitic acid (3.77±0.07-6.01±0.03%) were identified in the seeds oil. Omega-3 and omega-6 fatty acids contained 45.58-49.56% and 20.99-24.45% of total fatty acids in the seed oils, respectively. The highest amount of total sterols was detected in the seeds of S. virgata with 38.11 mg /100 g D.W and the lowest was measured in the seed S. nemorosa with 31.59 mg /100 g D.W, respectively. b-sitosterol, stigmasterol and campsterol were the main sterol constituents of the seed oils. In general, Salvia seed oils are rich sources in omega-3 and omega-6 essential fatty acids, as well as b-sitosterol and can be used in pharmaceutical and food industries.

The aim of this study was to assess the effects of forest logging on vegetation characteristics in forest of Shafaroud, Guilan. To do this, two regions, cultivated and control regions, with identical physiographical conditions were selected at Series 9 of Shafaroud forest. In each region, 25 main plots and in each of them, 4 sub-main plots were used in sampling to record the data on the vegetation. Also, soil samples were taken from center of each plot to measure tissue, bulk density, particle density, porosity, acidity of the soil and to analyze its nitrogen, phosphorus, organic matter, calcium, magnesium and sodium. After determining the plots centers, the vegetation sampling was done twice (one and five years after logging) in the cultivated region. The results showed that the control region had higher diversity and richness than the cultivated one. But the species dominance was lower in the control region. The Jaccard similarity index showed that the regions of control and 5-year after logging, have the most vegetation similarity compared with the others. Finally, the results suggest that the plant species concentration tends to be higher in the regions with high amounts of N, P, organic matter and soil porosity.

This study was designed aimed to investigated the allelopathic effect of olive pomace, laying on growth and biochemical characteristics of three cultivars wheat seedlings. Various concentrations of olive pomace (1, 3, 5 and 7 percentage) was mixed with soil and three different varieties of wheat were planted in the soil. After growth, the plant length, leaf and root dry weight, content of photosynthetic pigments, soluble carbohydrates and proline were measured in the seedling stage. The results shows that the plant lenght, leaf and root dry weight, photosynthetic pigment content, decreased in three varietis with the increasing amount of olive pomace in the soil compared to the control. But the amount of sugar and proline content shows Increase in wheats with increasing amount of olive pomace in the soil compared to control. According to the results obtained the inhibitory effects of olive pomace increased with increasing levels of olive pomace in the soil. Olive pomace has phenolic substances that its inhibitory effect can be attributed to these compounds.