مجله پژوهشهای گیاهی (زیست شناسی ایران)
سال بیست و هشتم شماره 4 (زمستان 1394)

Mycorrhizal fungi are essential element of farming systems and play an important role in improving the growth of plants. In this research, first, fungi were recognized mycorrhizal fungi in rhizosphere of Thymus daenensis in Tehran and Eyvan areas. In total, was seen nine species of this fungi that were belong to Glomus and Scutellospora genuses. In second, for the studing the effect of Gloums intraradices on shoot height, fresh and dry weight, nitrogen and polyamines content, inoculum containing spores and colonized roots with this fungi was introduces to plants that were grown in green house conditions. The percent of root length colonization was 47.71. No significant difference between control and treatment shoot dry weight and stem height were detected. But in terms of shoot fresh weight and nitrogen levels, this difference was significant and conjugated putrecine in treamtments was decresed.

Methyl jasmonate is a phytohormone widely distributed and plays an important role in some physiology activities in plant. Copper is an essential element for plants. On the other hand, excess copper is present in certain regions and environments, and can be potentially toxic to plants causing phytotoxicity by the formation of reactive oxygen species that damage cells. In this study, we examined impact of various concentrations of methyl jasmonate (0, 5, 10, and 20 µM) on reducing of oxidative stress in Garden cress (Lepidium sativum L.) under different levels of Cu (50, 100, and 200 µM CuSO4) copper stress.The results showed that copper stress treatment alone increased MDA, H2O2 and antioxidative enzyme activity like catalase (CAT), guaiacol peroxidase (GPX), ascorbate peroxidase (APX) and plant survival under copper stress. It is indicating that methyl jasmonate treatment caused decrease in oxidative damge and increase copper tolerance of plants significantly.

Rice (Oryza sativa L.) and Barnyardgrass (Echinochloa crus- galli L.) are annual plants and belong to Gramineae. Barnyardgrass is the most important weeds of rice paddies in Iran and the world. In this study, the effects of barnyardgrass allelopathy on anatomical characteristics of rice (Tarommahalli) at flowering and grain-ripening stages were investigated. Experiment were conducted to evaluate the effects of aqueous extracts obtained from root and shoot of barnyardgrass at 50% and 100% concentrations on anatomy traits of rice. The results of treatments with aqueous extracts of root of barnyardgrass at 100% concentration at both flowering and grain ripening stages showed an increase in number and size of silica grains on epidermal cells of stem and lower layer of leaf and well as increased size of stomata files. The cross-section of the rice stem showed that the number and size of silica knobs on its surface and also size of vascular bundles have increased. Rice treated with aqueous extracts of root from barnyardgrass indicated that as silica on the leaf and stem of rice increased, stem elongation was augmented and production yield also increased. Moreover, the treatment caused resistance to stem borer (Chilo suppressalis) and stem strength against lodging (stem stooping by wind and rain) occurred. The results revealed that the aqueous root extracts from barnyardgrass had positive effects on number and size of silica grains and silica knobs of leaf and stem which resulted in higher resistance and strength of rice stems leading to higher production yields of rice.

In this study effect of foliar application of salicylic acid and chitosan in low irrigation condition on quantitative and qualitative characteristics of Safflower (Carthamus tinctorius L.) (Goldasht) as a split plot experiment based on a complete block design with three replications was conducted. The main plot was irrigation at three levels on the basis of (A1) 75 % field capacity (control), (A2) watering 50 % of field capacity (mild stress), (A3) 25 % field capacity (high stress) and acid salicylic acid and chitosan as sub plots. Water stress significantly decreased plant height , number of branches, seed yield , seed weight, biological yield and harvest index , protein, carbohydrates and seed oil. Salicilic acid and chitosan increased all parameters instead of chlorophyll and leaf area index in control condition. The results showed that the biological yield in stress condition significantly was increased by chitosan and salicilic acid. In conclusion, Salicilic acid and chitosan are effective to reduce oxidative damages and increase the Safflower yield.

Camel, s thorn plant with scientific name Alhagi from Fabaceae family with non-edible fruit with medicinal properties is considered. Camel's thorn was a native of southern Europe and is found in many regions of Iran. Due to the lack of scientific information, regarding the characteristics of plant morphology, anatomical structure of vegetative and generative organs of the plant species Alhagi persarum was considered. Study of anatomical structure of vegetative meristem and flower with the fixator to stabilize the samples and passing the stages in preparation for embedding paraffin and slices at 7-10µm with microtome. Staining was carried out with Hematoxylin-Eozine. The sections were observed with light microscope and were taken picture from sample by photomicroscope .Vegetative meristem is composed of two layers Tunica and corpus. Flowers on this plant are complete, zygomorphic(irregular) and stamens are diadelphus.The tapetum is secretorial type. Ovule is anatropous and is covered with two layers of teguments.

Linum album of the member Linaceae is a herbaceous Iranian endemic medicinal plant, having podophyllotoxin (PTOX) metabolite. This important pharmaceutical compound used as a precursor for the synthesis of important antitumor drugs like Etoposide, Teniposide and Etopophos. Plant tissues culture is a appropriate method of increasimg secondary metabolits production. In this research, callus induction were investigated to regeneration under in vitro condition. Calli were initiated from shoot segment of young plant on Murashige and Skoog (MS) culture medium supplemented with (0- 0.4- 0.8- 1- 1.5- 2- 2.5 mg l-1) naphthalene acetic acid (NAA) and (0- 0.2- 0.4 mg l-1 ) kinetin (KIN) in the dark. The heaviest callus were obtained in 2 mg l-1 NAA with 0.4 mg l-1 KIN. Then, calli were transferred to MS medium supplemented with 6-benzyladenine (1-2.5 mg l-1 BA) either alone or in combination with 0.2 mg l-1 NAA for shoot regeneration. The 2.0 mg l-1 BA was identified more effective on shoot regeneration. For induction root from shoots, the optimal result obtained from half-strength MS medium supplemented with 1 mg l-1 NAA.

Heavy metals such as cadmium generating by urban activities, industrial and agricultural create abiotic stress in the plants which is one of the most important stress affecting physiological activities of plants. In this study, the effects of Cd was investigated on chlorophyll fluorescence (Fv/Fm, Fo, and Fm), photosynthetic pigments (a and b), and proline in one-year-old seedlings of Celtis caucasica and Robinia pseudoacacia. Saline solution containing Cd was sprayed on the leaves. The seedlings were treated during ten days, two times, with different concentrations of Cd (0 (control), 250, 500, 1000 and 2000 mg/L). Chlorophyll fluorescence was measured every other day during ten days. Chlorophyll and proline contents were measured ten days after Cd treatments. The results indicated that chlorophyll fluorescence of C. caucasica and R. pseudoacaci were affected slightly by high concentrations (1000 and 2000 mg/L) of Cd, so that Fv/Fm in both species decreased. The chlorophyll a of Robinia at 1000 and 2000 mg/L of Cd increased and in Celtis showed no significant difference in all treatments of Cd. The chlorophyll b showed no significant difference in all treatments of cadmium in C. caucasica and R. pseudoacaci. Proline content in the C. caucasica increased at 250, 500, 1000 and 2000 mg/L of Cd. C. caucasica and R. pseudoacaci were affected slightly by Cd. Photosystem II, chlorophyll pigments didn’t damage by Cd stress. Other physiological characteristics should be considered in future studies in order to selecting of tree species for afforestation projects in urban polluted areas.

Cuscuta L. (Convolvulaceae) species, as holoparasitic flowering plants, are weeds of the wild, horticultural and agricultural crop plants and have a vast distribution in the world. Pollen morphology of six species and seed morphology of five species out of nine taxa distributed in Khorassan provinces was investigated by using the light and scanning electron microscopy, in order to determine the significance of pollen and seed features as taxonomic characters. Results revealed that the pollen grains of Cuscuta are mostly oblate, zonocolpate and tricolpate. The largest pollen grain belongs to C. epithymum with 48.18 µm diameter in equatorial view and 44.82 µm in polar view. The smallest pollen grain belongs to Cuscuta campestris, with 30.95 µm diameter in equatorial view and 26.97 µm in polar view. Also, three distinct ektexine types are recognized including echinate, finely reticulate, and coarsely reticulate. Seed morphological study showed that seed shape, anticlinal and periclinal cell walls are the most important characters to separate the taxa. The results indicate that ultra-structural characters of pollen grains and seeds are useful for delimitation of Cuscuta species.

In the present research project effect of three culture medium and light intensity on carotenoides of algae, Dunaliella salina.In this study, Dunaliella species were collected from the lake and then was purified agar plate method. To study the effect of culture medium on the carotenoides of this species six treatments in triplicateof each culture medium by salinity 1.03, 2.99, 4.96 M in light intensity of 40, 120 and 200 micromol photon. m-2.s-1special culture module. Algae cells were counted regularly using Hemocitometry counting chamber in 3 replicates on daily basis. The growth curve was plotted out in Microsoft Excel software.
The carotenoides synthesized curve was plotted out in Microsoft Excel software and compared within treatments by means of two ways ANOVA Analysis.
Specific growth rate showed significant differences in various treatments (P

In order to comparison of tree species diversity were located 12 sample plots in 1 ha and 100×100 meters, and diameter at the breast height all of trees measured after registering species in the beech managed and unmanaged forest stands of Shastkalateh forest. Then, species diversity indices average based on basal area was calculated in sample plots and was used independent T-Test for comparison of average difference. In this study, richness indices (Margalef and Menhinick), heterogeneity indices (Simpson, Shannon- wiener) and evenness indices (Simpson, Smith-Wilson, modified Nee, Camargo) were calculated. The results showed that richness indices were significantly greater in managed stands. Average of heterogeneity indices were greater in managed stands and average of evenness indices were greater in unmanaged stands. But there are not significant differences in the 0.05 confidence interval. In general, richness and heterogeneity are more and eveness is less in manaed stands. Simpson, Smith- Wilson and Margalef indices calculated as appropriate indices for evaluate of heterogeneity, evenness and richness indices in the study area. According to the results of this research, single tree cutting is suggested as a appropriate approach for maintain and even increase of species diversity natural stands of north forests because it is follow of natural degradation condition in small scale.

The widely area of each state consist of rangeland with special vegetation and livestock in which are compatible to existing conditions. Livestock has special grazing and feeding behavior in pasture. Due to the large scale of rangelands area and high costs of improvement projects, this is essential to identifying the animal requirements and preference value of plant species for them before any practices. Winter and summer pastures in GarmSar city are mainly used to feeding livestock such as camel, sheep and goat. This research was conducted by using timing method to evaluate the preference value of the plant species for camel in summer and winter pastures for three consecutive years (86 -88). The results showed that camel feeds on thorny forb and thorny shrub such as Alhagi psedoalhagi, Halocnenum strobilaceum and Tamarix leptopetata in summer and winter rangelands. Other life form plant was consumed less than thorny plants and grasses such as psathyrostachys fragilis and does not used generally.

Silene sect. Auriculatae is represented by 36 species including 22 endemic species, is the most important section of the genus in Iran. A comparative anatomical study of stem and leaf of S. renzii, S. microphylla, S. parjumanensis, S. persica, S. rhynchocarpa, S. nizvana, S. gertraudiae and S. sojakii was performed at the population level from Iran. 19 quantitative and qualitative anatomical features of stem and 25 characters of leaf were measured on the 5 well prepared photographs. The taxa studied are distinguished by some anatomical features such as; cuticle thickness, dimension of epidermal cells, the location and dimension of crystal, the thickness of cortex parenchyma, the thickness of sclerenchyma layer, the number of vascular bundle in stem, the arrangement of phloem and xylem, the thickness of xylem and phloem tissue, the thickness of pith and mesophyll thickness. The results of the present research in accordance with the morphological study are confirmed the absent of S. rhynchocarpa in Iran, the ambiguity in nomenclature of S. renzii at intraspecific level and the distinction of Yazd population of S. microphylla from Semnan population.

Heavy metals pollution is a major problem for the large parts of the world. Lead is a heavy metal with high toxicity that absorbed by plants mainly through the root system and in minor amounts through the leaves. After entering the cells, lead inhibits activities of many enzymes, and affects membrane structure and permeability. The objective of this research was to evaluate the effect of different concentrations of Salicylic Acid (SA) and Ascorbic Acid (AsA) on the content of photosynthetic pigments and antioxidant enzyme activities of Ocimum basilicum L. under Pb stress. Factorial experiment in a completely randomized design with three replications was conducted. Treatments were combination of 3 levels application of Pb (0, 350 & 700 mg.l-1) and 2 concentrations of SA (0, 0.1 mM) and AsA (0, 100 & 200 ppm). The results revealed that increasing lead concentration reduced chlorophyll and carotenoid content and increased activity of antioxidant enzymes (SOD, CAT). On the other hand, application SA and AsA alone and/or together, significantly increased chlorophyll content and reduced activity of antioxidant enzymes. Generally, the results of this study indicate that SA and AsA applications improved plant physiological parameters of Ocimum basilicum L.

Bromus is a large genus of Poaceae. Some species are important as forages while some are famous weeds. This genus is distributed in different habitats of Iran by 44 species. In this project, 44 accessions of 13 species of Bromus have been studied for chromosome counting. Chromosome number of species were from 2n=2x=14 to 2n=6x=42. B. scoparius, B. sterilis, B. madritensis, B. briziformis, B. danthoniae, B. sericeus, B. pseudodanthoniae, B. tectorum, B. rubens var. rubens were diploid (2n=2x=14). In B. japonicus all accessions were triploid (2n=3x=21). B. oxyodon has 2n=4x=28 chromosome number. B. kopetdaghensis one diploid accessions with 2n=2x=14 and two hexaploid accessions 2n=6x=42 were observed for the first time. B. tomentellus was found to be pentaploid (2n=5x=35).

Lavaner (Lavandula angustifolia ) related to the lamiaceae family of plants .Lavander is a native of Mediterranean region of Europe and cultivated in many regions as medicinal and ornamental plant. This plant has antioxidant properties and this study was designed to evaluated antioxidant activity of Lavandula angustifolia leaf calli in MS medium supplemented with various concentration of NAA(1 and 2 mg/l ) and BAP(1,2,3 and 4 mg/l). The antioxidant activity and phenolics , flavonoids and rosmarinic acid content were determined. As a result the highest antioxidant capacity( Ic50:9.506±0.467 µg/ml) and the highest values of total flavonoid (0.0948±0.009 mg/gDW) and rosmarinic acid(27.867±0.086 µg/gDW) were obtained from the medium supplemented with 2mg/L BAP and 4 mg/L NAA . The biomass yield was significantly improved on mentioned medium. There was no significant difference between various media considering phenolic compounds. As a result tissue culture of lavender plant may be potent source of natural antioxidants.

The broad spectrum protective effect of the non-protein amino acid β-aminobutyric acid (BABA) against numerous plant stresses has been well-documented in the literature. This research shows a possibility to increase plant tolerance for drought stress through effective priming of the preexisting defense pathways in rapeseed plant. Results showed that rapeseed plants which were under drought stress had lower percentage of membrane stability index (MSI) and relative water content (RWC), higher lipid peroxidation products when compared with control plants. Pretreatment of plants with BABA increased the MSI and RWC and decreased the amount of aldehydes in water stress plants. H2O2 content was increased under drought stress. Pretreatment of plants with BABA decreased the amount of hydrogen peroxide. In drought stress condition, activity of SOD, APX, GR and POD were elevated over the controls while CAT activity decreased. In plants which pretreated with BABA and then exposed to drought stress the activity of mentioned enzymes increased.

The Khan Valley gallery forest with an area of ca. 80 ha is situated south of Urmia in west Azerbaijan province, NW Iran. Using transect method, this study examines flora, life form, and chorotypes of the plant species growing in the area. Woody plants were studied within fifty 400 m2 (20 x 20 meter) sample plots centered at 0, 20, 50, 100, and 200 m along transects perpendicular to the river axis on both sides at 200 m intervals. Herbaceous plants were examined within 100 m2 (10 x 10 meter) sample plots inside the main plots. In this study, 252 species belonging to 43 families and 169 genera were identified, of which Asteraceae, Brassicaceae, Lamiaceae, Fabaceae (Faboidae), Poaceae, and Apiaceae are most abundant in the study area. Our floristic study reveals that the most common plant taxa in the study site are therophytes (38.09%) and hemicryptophytes (34.92%), based on Raunkiær system, and phytogeographically belong jointly to Irano-Turanian and Euro-Siberian regions.

To perform any breeding work on seed, determination of its life ability amount via germination test is very important. In general, biotechnical tests present rapid methods for evaluating viability of seed samples and specificalty to assess non-germinable seeds which seems to be dormant through the measurement of weak or dead tissue. Tetrazolium test is the most common of these tests. This study aims to optimize Tetrazolium test conditions including concentration, temperature and storage time on seeds in Fagus orientalis. Factorial experiment was conducted in completely randomized design in three replications. the results of this experiment was compared with the obtained results from embryo culture test (in MS medium) for evaluating the best condition of tetrazolium. Soaking treatment of seeds for 18 h at 30°C in a solution of 0/5% Tetrazolium test results with the greatest similarity to embryos cultured was selected as suitable treatment for germination test using tetrazolium protocol in Fagus orientalis.

Ulmus glabra is a economical important tree species found in forests. However it is endangered due to high susceptibility to Dutch Elm Disease. Therefore, an efficient micropropagation method is important for breeding and genetic improvement of elm. This is the first report on induction of direct somatic embryogenesis from in vitro leaf explants in elm. The first experiment conducted with MS medium supplemented with different concentrations of BA or Kin or TDZ under light condition. Second experiment, carried out with MS basal media supplemented with 200 mg l–1 casein hydrolysed and different levels of 2,4-D and Kinetin in darkness. In third experiment 1/2 MS media supplemented with 200 mg l–1 casein hydrolysed and low levels of 2,4-D in combination with Kin were used, and the effects of light and darkness were investigated. Globular somatic embryos were achieved directly just on small leaves of genotype 2 in experiment 3. Non-embryogenic calli were induced in other experiments. The frequency of embryogenesis in most of the treatments of experiment 3 was 100%. However high number of embryos per explants was achieved in presence of 0.2 mgl-1 2,4-D without Kin (60.48) and 0.4 mgl-1 2,4-D combined with 0.2 mgl-1 Kin (47.76). Additionally, the percentage of embryogenesis and the average number of embryos per explants were higher in dark compared to the light condition.

Morphogenesis of flower buds of two commercial apricot cvs. ‘Noori’ (early blooming) and ‘Shahroodi’ (late blooming) were studied in Karaj climatic condition. The effect of foliar application of gibberellin (GA3, 250 mgL-1) on flower bud development of two cultivars was also studied. GA3 was applied at three times during autumn (first week of October, third week of October and second week of November). Scanning electron microscope was used to study flower bud development. Based on results, the first stage of flower bud development in both cultivars showed the same growth pattern. Growth of floral parts was continued until the beginning of dormancy period. Stamens were developed, but no pollen grains were formed during the autumn. At this stage, pistil developed and ovarian cavity was observed in both cultivars in mid-November but no ovules were observed. Both cultivars were different in second and third stages of flower bud development. Final stage of flower bud development was earlier in ‘Noori’ in compare to ‘Shahroodi’. The results showed that all three times of foliar applications of GA3, were delayed final stage of flower bud development and the longest delay was with exogenous application of GA3 in mid-November. The results suggested that the application of GA3 at autumn increased GA3 levels at dormancy stage, thus the flowering was delayed that is a way to avoid to exposure to late spring frosts. So, the differences between both early and late blooming cultivars can relate to the content of gibberellin within flower buds during dormancy stage.