مجله پژوهشهای گیاهی (زیست شناسی ایران)
سال بیست و هشتم شماره 5 (زمستان 1394)

Investigation of ecological properties of plant species products basic information for ecosystems management. In this research, the ecological properties of two species H. globiferum and H. aucheri were studied in Qushchy rangeland at 70 km of Orumieh- Gharedagh road. These species belong to the Composite family and are the multipurpose species that are used as forage, medicinal plants and soil conservation. 1m2 plots were used to determine the density and canopy cover and cut and weight method was used to measured production at different elevations. Soil chemical and physical properties were studied in their habitats. The amount of nitrogen, phosphorus, potassium and carbon, also forage quality of species were measured. The climate condition and penology of these species were studied. The results showed that H. globiferum had more cover percentage, density, frequency and production than other species. Soil studies showed that both H. globiferum and H. aucheri had more distribution in clay – sand soils with low alkalinity. Above ground parts of studied species had more nitrogen, phosphorus and potassium than underground parts, also amount of them were more in H. aucheri than other. In general, H. globiferum had more production and cover percentage then can be use as medicinal and soil conservation species and H. aucheri had more quality and nutritional value for animal forage.

Biodiversity at all levels of study and research, it is always noteworthy and appropriate strategies, to determine the sustainability and maintain ecosystems in natural resource management has been the state pen. This study compared Corticolous lichen diversity in two populations predominantly parottia – Carpinus and Acer velutinum (with relatively similar physiographic features) is in the forest of South Noshahr. For statistical study, 30 selected pieces (15 pieces of each type) in each plot type and percent cover of lichen species using frames (quadrates) 60 × 40 cm at breast height of trees located was the lichens were harvested Survey data showed that 38 species belonging to 14 families and 41 species belonging to 17 families in Acer velotinum type in the parottia - Carpinus found .The mean value of Shannon - Weiner and N Hill in the parottia - Carpinus, respectively, 3.252, 8.274 and type Maple 2.162, 3.073 and the mean species richness and evenness in type Ironwood - Carpinus (21.641 , 0.851) higher than the platform type (20.124, 0.461), respectively, The main reason it can be distributed and the presence of different tree species with different ecological characteristics, the mass of interwoven hornbeam - Gospel attributed.

Investigation of plant diversity of country as a essential bed to studies of ecosystem, PASTURE , plant gen bank, agriculture and medicine is of much considerable important. In this research the flora of Saverz mountain in the Kohgiloyeh country from Kohgiloyeh and boyerahmad province has been investigated. This region is located in the 80 kilometers away in the southwestern of yasuj. the research by collecting the essential information in order to floristic study started. The plants of region has collected and pressed, then we provide a samples of herbarium and in centeral herbarium of yasuj university with use of existing flora resources have been identified. This investigation showed that in the saverz mountain, there are sixty two families ,two hundreds and two genous, two hundreds and ninety five species than include 6.44% of Phanerophytes, 5.76% chamephits, 46.78% Hemicryptophytes, 12.88% geophytes, 26.78% Therophytes and low percentage of hydrophytes and parasites. Also in this research, the growth region of existing species in this region has been determined. Analyses shows that most of species of region belongs to the growth area of Iran-o-Turanian Region with having 67.7% of region flora. Number of 47species of Iran endemic , 47 of rare species, 60 of medicine species, 52 of poison species of total of two hundreds and ninety five species has identified and determined and 74 species is of waste potential or is prone to waste and weedy.

To study the effect of 5- aminolevulinic acid (ALA) on some physiological responses of Capsicum annuum under drought stress, a factorial experiment in randomized complete block design in four replications was carried out in greenhouse. This study was conducted with two main factors, 5-aminolevulinic acid in four concentrations (0, 0.25, 0.5, and 1 mM) and drought stress in three levels (irrigation at 100, 60 and 30% of field capacity). Exogenous application of 5- aminolevulinic acid protected pepper against drought stress that its protective effect was related to regulation of antioxidant enzymes. 5- aminolevulinic acid had significant effects on yield, total phenols, soluble sugars, polyphenol oxidase and superoxide dismutase activities, hydrogen peroxide concentration and leaf area, tolerance and harvest indices. In drought stress condition, total phenol content, soluble sugar contents, free radicals, hydrogen peroxide and activities of superoxide dismutase and polyphenol oxidase enzymes in leaves increased while growth parameters decreased. Thus it can be stated that the pepper plant treated with 5 - aminolevulinic acid the activity of antioxidant enzymes and compounds such as soluble sugar and total phenol improve and amend the effect of drought stress on the morphological and physiological characteristics.

In order to evaluate the physiological and morphological traits and Photochemical efficiency of photosystem II of Salvia leriifolia under freezing stress in controlled condition, an experiment was carried out as a factorial experiment based on completely randomized design with three replications in Ferdowsi University of Mashhad. The plants exposed to twelve freezing temperatures (0, -2, -4, -6, -8,-10, -12, -14, -16, -18, -20 and -22˚C) in seedling stage. Leaf area and dry weight, root length and dry weight, Electrolyte Leakage (EL), survival percentage after three weeks and chlorophyll fluorescence parameters in recovery periods (0, 6, 12, 24 and 72 hr. after stress) were studied. Results showed that effect of freezing temperatures on all traits were significant (P≤ 0.001). EL increased significantly with decreasing temperature and reached to maximum 83% at -20 ˚C. Although plant survival percentage did not affect until -14 ˚C, all seedlings were died in -220C. Lethal temperature based on survival (LT50su) and electrolyte leakage (LT50el) were -17.0 and -11.8. Results also indicated that Reduced Dry Matter Temperature 50% (RDMT50) was -16.5 °C. Photochemical efficiency of photosystem II (F′v /F′m) was not affected up to -6˚C, but it decreased by 70% with decreasing temperature to -22 ˚C. F′v /F′m decreased by 40% during 24 hours after recovery compared to control, but it increased when recovery continued to 72 hr. Results also indicated that EL had negative correlation with survival percent (r= -0.82***) and F′v /F′m (-0.95***).

In order to study the allelopathic potential of wheat aqueous extract on germination and early growth of two summer weeds (redroot pigweed and dodder) two separate experiments were conducted using randomized complete block design with 3 replications. Plant materials for extracting were obtained from our original wheat field which has been grown in research field of Tarbiat Modares University during 2010 – 2011 growing season. In each experiment wheat areal parts in three phenological stages (tillering, soft dough and physiological maturity) were extracted into different concentrations of (25, 50, 75 and 100%). The extracts were treated on weed seeds following to the procedures of International Seed Testing Association (ISTA). The result showed that wheat shoots extracts have allelopathic effects depending to the stage of plant phenology and the weeds species sensitivity. In general, increasing concentrations of extract significantly reduced final germination, the number of normal seedlings, coefficient of velocity and length of weeds seedling, So that the highest inhibitory was observed in complete concentration (100 percent). Overall, the extracts of wheat shoot particularly in tillering and maturity stages have the most negative effect on germination indices of redroot pigweed and dodder respectively. This finding is agreeing with total phenol measurement of wheat extract especially in tillering stage. Therefore application of wheat green manure in tillering stage or mixing the plant residues with the soil could be considered as a non-chemical strategy for weed control in following summer crops.

Stomatal traits are of interest in physiological studies and in the development of cultivars to improve to drought resistance. To consider effect of terminal drought stress on Stomatal traits of barely genotypes, a field experiment was conducted in research farm of Zanjan University in 1390-1391. The experiment was done on two groups of barely genotypes including 32 landraces genotypes selected from ICARDA barely gene pool and 24 Iranian cultivars in simple lattice design in both well-watered and terminal drought condition by stopping watering after flowering time. Significant variation was found in stomatal frequency and size between genotypes in both flag leaf surfaces in drought and control conditions. Stomatal frequency was negatively correlated with stomatal size. There were significant changes in genotype rank order for stomatal frequency and size in different water stress conditions. Results showed that Stomatal frequency increased under dry environment and the effects of drought stress on the Stomatal traits in lower surface of leaf stomatal are more than upper surface.

The purpose of this study is to identify plant communities of Gharabagh rangelands in Azerbaijan province and determining effective factors on their distribution. So, sampling was performed using random-systematic method in the key area. Sampling was done along 4 transects of 150 m which were vertical, in each site. Quadrate size and numbers were respectively determined using minimal area and statistic methods and 15 plots of 1 m2 were placed 10 m away from each other along each transect. Soil samples were taken from 0-20 cm at the first and end points of each transect according to the soil depth and gravel, clay, silt and sand percentages, organic matter, pH, lime, electrical conductivity, potassium and phosphorous were measured. Species type and vegetation cover were also determined. Two-way indicator species analysis (TWINSPAN) and principal components analysis (PCA) were used to plant communities and determining the most important factors affecting distribution of plant communities, respectively. The results showed that there are five ecological groups in the study area which were conformed to the plant. There is also a relationship between the plant communities' distribution and environmental factors and the parameters like texture, lime, nitrogen and potassium have the greatest impact on the distribution of plant communities among the study factors.

In this study, abundance change of Arbuscular mycorrhizal fungi (AMF) and root colonization of indicator species were investigated in relation to plant biodiversity indices in different ecological groups. Plant species composition was assessed on 53 sampling plots with area of 400 m2 located systematically on a 150 m × 200 m grid that extended at 400 m to 1700 m above sea level. TWINSPAN (Two Way Indicators Species Analysis) method was employed to classify sampling plots into six different ecological groups. Species richness, diversity, evenness and dominance indices were calculated in each sampling plot. The phytosociological data revealed obvious differences in the plant species biodiversity among ecological groups. AM colonization and arbuscular mycorrhizal fungi (AMF) spore densities were also differed in ecological groups and were significantly related to some of biodiversity indices. There was no relationship between spore numbers and plant species richness, but diversity and evenness reduced with increasing spore densities. In contrast, evenness indices showed significant positive correlation to spore densities and AM colonization.

Plants grown starts from seed germination stage and continues with the seedling in soil. To evaluate the role of mucilage on improving of drought tolerance of Lepidium sativum L. in seed germination and early seedling growth a completely randomized experiment was conducted in a factorial arrangement with four replications. Drought stress levels (0, -5, -9, - 14.5, -21 MPa) and seed type (with mucilage, and without mucilage) were considered as first and second factors, respectively. Results indicate that seed germination percentage, speed of germination, shoot and root length as well as seed vigor were significantly reduced (p

Seed dormancy is a defensive system against unfavorable environmental conditions. This research was designed to evaluate the drought stress effects on seed germination and dormancy of Hordeum spontaneum genotypes. Therefore, 19 genotypes of the species and the Nosrat (cultivated barley) cultivar were evaluated under normal water condition and drought stress in a green house study. Complete randomized block design with three replications were used in this study and two stress levels including 95-100%FC and 25-30% FC, were imposed to the plants. Based on results, drought stress had significant effects on germination index, germination percentage, seed dormancy, germination value and germination energy. Drought stress increased the seed dormancy in most of Hordeum spontaneum genotypes. Principle components analysis of the traits in both water conditions showed that, stress tolerance index and length of coleoptiles are positively related, which indicates that genotypes with longer coleoptiles are more tolerant to drought stress conditions, and it seems that, this trait has evolved to increase the adaptation to drier climates.

Saltbush (Atriplex leucoclada) is one of the endemic halophyte plants of Iran, useful for desertification, restoring and modifying rangelands in arid and desert areas cultivation. To assess the effects of mechanical and chemical treatments in break seed dormancy and to stimulate seed germination in dimorph seeds of Atriplex leucoclada, two tests were performed in completely randomized design with three replicates for both of its two seed types. Treatments were: scratch pre-treatment, gibberellic acid or kinetin, ethephon, potassium nitrate or thiourea all performed for 24 h or 48 h at 4˚C or 20˚C, pre-treatment running water, moist chilling (20 days/4˚C) + 14-days treatment with gibberellic acid or potassium nitrate or thiourea, scratching with a sand paper, making a gap with a needle, hot water (70˚C or 90˚C for 15 min), sulphoric acid (75%), dry-storing (3 months/20˚C), stratification (3 months/4˚C). As the twice-scratched pretreatment caused the highest germination percentage (73.3%) and vigour index (8860) in the brown seeds and for the black ones these values were 63.3% and 7710, respectively. Overall, it is concluded the seed dormancy in both types of seeds in A. leucoclada could be physical.

The Effects of priming by different levels of salicylic acid (SA) and sowing dates on nutrient elements concentration and distribution in the parts of wheat spike, cv. Alvand, was investigated under field conditions. The factors were including seven levels of priming by SA (0, 400, 800, 1200, 1600, 2000 and 2400 µM), two sowing dates including conventional sowing date (23 October) and late sowing (22 November) and spike parts (Above, Middle and Below) was evaluated. Results showed that interaction between sowing dates, SA and spike different parts were significant on all elements. Salicylic acid improved amount of macro and micro nutrients, especially in the upper and middle parts of spike. Among the priming levels, 400 µM concentration of SA had highest values than other primed levels and control treatment on nutrient elements. It seems that the central section seeds of spike due to greater speed and duration of grain filling showed higher nutrient elements concentration. The highest concentration of nitrogen, phosphor, iron and manganese was found in middle part of spike. But, the highest value for copper observed in upper part and for potassium in lower part of spike. Generally, wheat seed priming with salicylic acid increased concentration of macro and micro nutrients elements, especially in the upper and middle parts of spike.

In this study effect of different hardness of 0 (control), 200, 400, 600 mg CaCO3/l of culture medium on purification and colony formation of green alga Scenedesmus quadricauda were investigated. Results showed that medium hardness had significant (P

In order to evaluate the allelopatic potential of Eucalyptus camaldulesis alcoholic extract on antioxidant enzyme activites, cell membrane damage and sucrose synthesis enzymes activity of Xantium strumarium, the expriments was coducted in Islamic Azad University, Shoushtar branch at 2012. The experiment was laid out according to Completely Randomized Design with four replications and treatments were various concentration of E. camaldulesis alcoholic extract (0, 4, 8, 12, 16 and gr/L). Results indicated E. camaldulesis alcoholic extract application exhibited gradual rise inhibitory effect on seedling weight, antioxidants enzymes activities and sucrose synthetesis enzymes activity but elevated the malondialdehyde concentration in Xantium strumarium seedlings. The lowest sucrose synthesis activity (2.11 nmol prot-1 min-2), seedling dry weight (2.76mg) and highest malondialdehyde concentration (0.92 nmol gr fw-1) were noted at 20 gr L-1 concentration of E. camaldulesis alcoholic extract. In conclusion, E. camaldulesis alcoholic extract decreased seedling growth, chlorophyll content, antioxidant enzymes activates and sucrose synthesis enzymes activity of X. strumarium seedling.

One of the most important and applicable tissue culture techniques is micropropagation. Lisianthus (Eustoma grandiflorum) is an ornamental plant which studies on its micropropagation is insufficient. The aim of this study was to evaluate the effect of different concentrations of NAA and KIN on micropropagation of lisianthus. For this purpose, the explants were cultured on MS medium with different concentrations of NAA and KIN (0, 0.5, 1 and 2 mg l-1). Results showed that the longest shoot (2.325 cm/explant) was obtained in medium containing 1 mg l-1 KIN (without NAA). The largest number of shoots (with average of 2.800 and 2.550/explant) was produced in medium containing 1 and 0.5 mg l-1 KIN (without NAA). The highest number of node (with average of 8.358/explant) was obtained in medium supplemented with 0.5 mg l-1 (without NAA). Maximum number of roots (with average of 2.650/explant) was produced in medium containing 0.5 mg l-1 NAA along with 2 mg l-1 KIN. Regenerated plants showed 100% survival in ex vitro conditions.

Pennyroyal (Mentha pulegium L.) is a medicinal plant of the Labiatae family. In this study, it was investigated the effect of salinity on leaf area, shoot length, root length, activities of superoxide dismutase (SOD), peroxidase (POD), polyphenol oxidase (PPO), catalase (CAT), and ascorbate peroxidase (APX) in pennyroyal species. Seeds were sown in Tref peat in greenhouse conditions with 16 h light/ 8 h dark period per 24 h and day/ night temperatures of 25/ 18 ˚C. Then, 60 days seedlings transferred to pots containing perlite and grew in hoagland solution with different concentrations of 0, 25, 50, and 75 mM NaCl. Seedlings were harvested for physiological and biochemical analyzes, after four different harvest times (10, 20, 30, and 40 days). The results showed that leaf area and shoot length decreased with increasing salinity levels, whereas root length increased to 50 mM NaCl and then decreased. Delay in harvest time caused more decrease in leaf area and shoot length. With increasing NaCl, activity of all the enzymes significantly increased at four harvest times. Activities of SOD, PPO, and APX were higher in root than that of leaf and shoot, whereas CAT activity was higher in leaf. On the basis of the obtained data, it can be concluded that pennyroyal reduced negative effects of salinity stress with increasing activities of antioxidant enzymes in leaf, shoot, and root. Antioxidative response of M pulegium has a direct relationship to salt stress time duration.

Crataegus from Rosaceae family is a tree that has medical and ornamental applications. Seeds of this genus have germination problem. There are limited data about germination of different species. Therefore, study on germination of three native species of Iran C. persica, C. assadii and C. babakhanloui is conducted and the best and most effective treatment is determined. To evaluate the germination and breaking seed dormancy of three species, an experiment was carried out as a completely randomized design with twenty two treatment and three replications. Seeds were imposed under physical and chemical stimulator treatment¡ including, scarification and warmth followed by cold stratification, giberlic acid, kno3 & Sulfuric acid. Results indicated that in all treatments scarification is effective for permeability to water of seed coat and breakage of seed dormancy. The highest percentages of germination are in treatments 'sowing the seeds outdoors at the beginning of summer" and 'running water followed by warmth and cold stratification'.

In this research, the effect of pretreatment of seeds with arginine (amino acid precursor of nitric oxide and polyamine) on growth parameter, Kﳖ ratio and reduction of oxidative damages induced by salinity (300 mM) were investigated in wheat plant.. Results showed that salinity stress had no significant effect on growth parameters while increased the total oxidative stress index such as lipid peroxidation hydrogen peroxide content and antioxidant enzymes activity. Saking of seeds in arginine (0.5 mM) for 24 hours, reduced the lipid peroxidation and hydrogen peroxide in plants which were under stress. In plants which were under salt stress, pretreatment of seeds with arginine also increased the activity of root and shoot GPX and shoot APX enzymes when compared with non pretreated plants. In this research the K /Na ratio decreased under salt stress and arginine pretreatment increased this ration in plants. According to the protective role of some arginine metabolism compouns such as nitric oxide and polyamines that report in previous study,in this research it seems that arginie caused increasing salt tolerance directly or indirectly throuth some compounds such as nitric oxid and polyamines production

Ornamental Amaranthus (Amaranthus cruentus) is one of the valuable ornamental, medicinal and edible plants .The A. cruentus seeds plant have problem in germination and number of few cultivated seed will germinated. Therefore, in present study the effect of treatments includes: sulfuric acid, freezing, boiling water, wetting and drying, cold and scarification were investigated on break dormancy of this plant seeds and germination percentage and velocity of germination were determined. This study were done based on Completely randomized design experimental design with with 4 replications in Petri-Dish in Germinator. Then, obtained data along the experiment were analyzed using SPSS package (p