Journal of Plant Research
Year:2015 | Volume:28 | Issue:3|Papers Count:19

The effect of drought stress and application of mineral zeolite was evaluated on morphological and physiological traits of mallow on complete random blocks design with three replications in greenhouse conditions in Maragheh (2011). Factors including, drought stress (control (100 percent FC), mild drought stress (75 percent FC) and intense drought stress (50 percent FC)) and zeolite (0, 2, 4, 6, 8 gr/kg soil). Significant differences were observed between the treatments. The results show that the highest shoot fresh weight (164 gr), root (87.66 gr), shoot length (79 cm), stomata conductance (875.00 milli mol/m2/second) electrolytic leakage (87.72 milli mol.cm-1), a and b chlorophyll (25.72 and 9.06 mg g-1) were observed in 8 gram zeolite and 100 percent moisture field capacity. Also the highest amount of soluble sugar (155.20 mg.g-1 DW) and prolin content (1.41 mM.g-1 FW) was belong to zeolite control level, 50 percent moisture field capacity. The application of different levels of zeolite in each three moisture conditions improved agricultural traits. Totally, the results of this research shows that the application of zeolite in combination with soil prevent from water waste and facilitate water availability to plant.

Rice (Oryza sativa L.) is a member of Gramineae and umbrella sedge (Cyperus difformis L.) is one of the common weeds of the rice paddies. An experiment was set up in order to investigate the allelopathic effects of aqueous extracts obtained from root and shoot of umbrella sedge with 50% and 100% concentrations on seed germination and seedling stages of rice. The results showed that aqueous extracts reduced germination percentage, germination rate and total dry weight of rice compared with control (%72, 0.884seed/day and 0.322g respectively) and the difference was significant (p£0.05). At the seedling stage, the shoot length of the rice plant was reduced with all treatments and was not significant. Moreover, water content of seedling leaves was increased with all concentrations but with 50% root‘s extract (%50.90g) compared with control (%53.07g) was declined significant (p£0.05). The fresh and dry weights of shoots increased in the all treatments in comparison with control (0.0764g and 0.0123g respectively) and difference were significant (p£0.05). The fresh weight of root also increased with both extracts of root and shoot at 50% concentration but the increase was not significant. The results showed that seed germination stage of rice was significantly inhibited by all aqueous extracts of umbrella sedge (p£0.05), but the aqueous extracts of umbrella sedge had different morphological and physiological effects on seedling stage that depended on organ type e.g. shoot length decline was not significant, but fresh and dry weights of shoot and water content of seedling leaves showed significant increase (p£0.05) compared with control.

Recognition of vegetation and study of their ecological features are considered a criterion for the quality of forest ecosystems. So such researches in these habitats is necessary in order to study floristic combination accurately since according to their outcomes, we can predict the trend of future changes and preserve endangered plant species. Therefore, this survey was done in order to study one of the most significant plain forests in the south of Caspian Sea relying on plant characteristics in outdoor recreation zone. First of all, 80 plots were chosen by means of random-systematic sampling. Then features of quantity and quality related to tree, shrub and herbaceous coverage in those plots were measured. In this matter, density, coverage percentage, frequency, abundance and presence for forest stand and forest coverage were calculated.According to the results, 35 plant species including 17 tree species and 18 herbaceous species were recognized in outdoor recreation zone of Sisangan forest park. The relationship between the coverage percentage of upper storey and forest bottom plants reflect the relationship between falling rate of upper storey and rising rate of forest bottom coverage. All in all, in outdoor recreation zone, the frequency of Buxus Hyrcana and Carpinus betulus is dramatically more than other species. As a matter of fact, considering their conservation importance, full attention to this reserve is essential.Taking everything into consideration, in order to preserve plant species of this area, it is necessary that responsible organizations pay special attention to this reserve where conservation plant species according to the red list of IUCN exist.

Nitrogen cycle includes fixation, mineralization of nitrogenous organic compounds, nitrification and denitrification that microorganisms have important role. The aim of this project was to study of microbial population involved in nitrogen cycle, nitrification potential and nitrate reductase assay in disturbed and undisturbed habitats of beech (Fagus orientalis). Microbial population of ammonium oxidizer, nitrite oxidizer and denitrifier were measured by MPN method. Nitrification potential and nitrate reductase assay was done by colorimetric methods. Results indicated difference between disturbed and undisturbed habitats in microbial population, nitrification potential and nitrate reductase activity. The highest amount of microbial population was seen in optimal stage of undisturbed habitats. The amount of microbial population was higher in undisturbed habitats than disturbed ones. This may result from better ecological situation for microbial growth in undisturbed. Nitrification potential was more in disturbed habitats in spring but less in disturbed habitats in fall due to decrease of temperature and plant exudates. Nitrate reductase activity was more in disturbed habitats in Gilan in both seasons that indicates more substrate for enzyme because of habitat disturbance. But in Mazandaran habitats nitrate reductase activity was more in undisturbed habitats. In conclusion it seems microbial parameters are good tools to determine soil condition in forest ecosystem.

The present study was aimed to measure the rate of litter decomposition and home field advantage in Pinus brutia. Ten and Quercus castanefolia monocultures in Darabkola- Mazandaran. Fresh fallen litters were collected from the forest floor of those stands and after drying in Lab (65°C) were placed into litterbags (2 mm mesh). Three categories of litterbag were prepared and located on the mineral soil surface after removal of organic layers. One pocket bags filled with pure leaf and needle litter (10 g), one pocket bags filled with mixed litter (5g needle and 5g leaf) and two pocket bags filled with mixed litter (10g leaf and 10 g needle in each pockets, separately but connected). During one year incubation period, litterbags were collected from the field after 2, 4, 6, 8 and 12 months. Results showed that, the annual average of decomposition rate for pure needle in pine stand (4.01) was lower than in oak stand (4.18) but for pure leaf in pine stand (4.60) was higher than oak stand (4.58). The decomposition rate of mixed litter (two pocket bags) in oak stand was higher than in pine stand. Measuring of home field advantage showed that, litter decomposition rates were increased in home stand after 180 days.

The aim of this research was the studying influence of endemic and exotic afforestation on biodiversity of plant species and woody regeneration in Qaemshahr Chai-Bagh district, located in Mazandaran Province. Due to, 2 hectare area were considered in afforested stands of Acer velutinum, Alnus subcordata, Cupressus sempervirens, Pinus nigra with control area. To doing this research, 15 sample plots with 20m × 20m area were taken in each plantation and also control area. We recorded type and individual of woody regeneration with covering percent all of herbal species in micro sample plots with 1m × 1m area. For biodiversity analyses; Simpson, Shannon Wiener' s, McIntosh diversity; Margalef, Mechanic's richness; Pit and Hill's evenness indices were employed. Analyses of variance whole studied indices (for plant species and also woody regeneration) were significantly different among afforested stands. About plant biodiversity, the control area showed the most values of Simpson, McIntosh, Margalef, Mechanic, Pit and Hill's indices whereas the maximum of Shannon Wiener was detected in Pinus nigra stand. But, about the woody regeneration the greater amounts were observed in Acer velutinum for all of biodiversity indices. According to these findings, it is recommended that broad-leaved has more priority compared to needle-leaved for afforestation due to biodiversity (especially woody regeneration) development and conservation. Planting of need-leaved species should be considered in especial condition and with especial purpose beside precision studies of region ecosystem.

The stability and health of natural ecosystems can be dependent on plant species diversity. So determination the factors that control the diversity and have positive or negative effect on plant species diversity are very important in the ecology. With this aim four Oak (Quercous persica) sites in Ilam city were selected on the basis of history of management and disturbance: conservation management for 5 years, conservation management for 20 years, highly disturbed and undisturbed. The area of each site is approximately 100 hectare. Systematic-random sampling method (100×200 m) was used to gather data from 50 plots (400 m2) within each site. Three soil samples at the depths of 0–30 cm were randomly taken around the center of each sampling plot using soil auger, and then mixed to obtain 1 composite sample for laboratory analysis.Shannon index was used to determine the plant diversity. In this study the direct and indirect effects of each independent variable on the dependent variable evaluated using path analysis. Result showed that CEC, K+, mg++, NH4+and percent tree canopy had a positive direct effect on of Plant species diversity. Between these factors NH4+had the greatest influence. The most important factor in changing the Plant species diversity has been destruction, but it has a negative role by changing some soil properties and tree canopy.

In order to select new rootstocks For water stress resistance and the identification of biochemical markers associated with this conditions were investigated the effect of water stress and Effective microorganism on the biochemical properties of rooted cuttings of almond rootstocks in Department of Horticultural Science of Ferdowsi University of Mashhad during 2011 -2012. In this research effects of two concentrations of EM (0 and 1%) and three irrigation levels {normal irrigation (control) and irrigation after depletion of 33 and 66% of available soil water}, and four rootstocks of Almond {Selected natural hybrid of peach × almond (H1and H2), GF677 and vegetative rootstock of almond (local control) were evaluated. This experiment was arranged as a factorial experiments based on a randomized complete blocks design with four replications. The measured traits were seedling survival, chlorophyll A, B and total, soluble sugars, starch, protein and proline content in leaves and roots. Analysis of variance showed that effect of rootstock and irrigation levels in all the studied traits were significant at the %1 level. The results showed that effect of Effective microorganisms on starch, protein and proline content in leaves and roots and chlorophyll A were significant 1% level and chlorophyll B was significantly different at 5% level. Consumption of Em, reduced proline and starch in the leaves and roots compared to control but protein was increased at 5% level. Chlorophyll content was different with type of chlorophyll and treatment. According to the results, the characteristics of proline, soluble sugars and proteins of leaves are suitable markers for evaluation of water stress in almond and the H1 rootstock (natural hybrid of peach × almond) was identified as resistant to drought.

The leaf litter decomposition dynamics of four types of leaf litters including Oriental Beech (Fagus orientalis Lipsky), Caucasian Alder (Alnus subcordata C.A.Meyer), Velvet Maple (Acer velutinum Boiss.) and Norway spruce (Picea abies (L) Karst) was studied for 400 days at pure Norway spruce plantation using litterbag method in Lajim Region. In this study limit values of Norway spruce needles were calculated in both pure and mixed mode. The finding of this study showed that limit values of decomposition varied in litter types and it was the least (0.43) in Caucasian Alder leaf litters with highest initial Nitrogen concentration. The results showed that mixing leaf litters with Norway spruce needles significantly had a positive effect on Norway spruce needles decomposition rate. In addition, Norway spruce needles have the least limit values (56.66) in pure mode. Among mixed modes, Norway spruce needles mixed with Oriental Beech leaf litters showed the highest limit value rate (95.33).

Wetlands are characterized with unique flora and vegetation in southern slopes of Alborz Mts. To date, there are scares studies related to mountain wetland indicator species and the main factors affecting their distributional patterns. The aim of the project is to test a hypothesis that represent the considering the wetland species as ecological indicators. To reach this aim, the relationships between altitude, soil properties and the occurrence of indicator species (in 512 relevé) were examined by using TWINSPAN analysis and ecological profile method. Out of 41 studied plant species, 11 species were identified as indicator species in three vegetation groups by TWINSPAN analysis. Group I, with Ligularia persica, Gypsophila elegans were restricted in high altitude (>2500 m) and in acidic (<6.3) and sandy soils (>55%), Group II, with Pedicularis sibtorphii and Carex diluta were observed in the middle level of ecological variables particularly altitude (2050-2550 m) and pH (6.4-7.6), and Group III, with Schoenoplectus lacustris, Carex songorica and Lythrum salicaria have found in the lower altitude (<2000 m), where soil is characterized by high pH (>7.7), EC (>10 ms/cm) and percent of clay (>36%). Finally 12 plant species (out of 41) had significant relationships (p<0.05) with altitude and soil variables by using ecological profile method.

Saponins as secondary metabolites that are found in many plants and some animals are high molecular weight glycosides, consisting of a sugar moiety linked to a triterpens or steroid aglycone. Many saponins have detergency properties and give stable foam in water. Members of the genus Verbascum L. are characterized by yellow flowers and mostly smoke crack and thick leaves. The Verbascum species have active chemicals, which can reduce cyclooxygenase activity. Quantitative and qualitative studies of saponins from the aerial parts and roots of three Verbascum species, namely Verbascum nudicaule, Verbascum sinuatum and Verbascum speciosum were carried out by spectrophotometry and TLC method. In this study, 5 fractions were obtained from each section. Among three species studied, Verbascum speciosum showed high content of saponins in root and also aerial parts. In addition, thin layer chromatography of the extracts of three species on TLC plates represents some saponin spots with different Rf values in the range of 0.13-0.73.

Salvadora oleoides is a shrub or small tree, ever green or semi deciduous is extended in arid and warm regions of India, Pakistan and south east of Iran. In order to survey some phenological phenomens with climate and physiographic properties, this study was carried out in the south-east of Iran from 2008 to 2011. In first step, distribution of species was recognized in Baluchestan province, and then 6 habitats were chosen. These habitats were visited in 2-3 week intervals annually. Three trees were marked in each site and were monitored during four seasons and its phenological stages were recorded.Climatic data were gathered and phenological stages were analyzed. The results of phenological and meteorological data indicated that the growth patterns of Salvadora oleoides may alter with annual temperature and precipitation, distribution of rain and height of sea levels. Salvadora phenological stages are long term and vary 138-148 days in different regions. Buds begin to sprout in February to March and flowers appear in March. Round and green fruits appear on young branches in April. Fruit ripening start in June and fruits are starting to drop in July. In mountain regions, beginning of phenology is done 1 to 2 weeks after another sites. In eastern habitats (near to Pakistan) phenological stages occur in spring and fall. But raw fruits and flowers starting to drop when temperature decreases in autumn. In all conditions, amount of Growth Degree Days (G.D.D) required for ripening fruit is the same and equal to 1500oC.

The application of medicinal plants for the treatment diseases in humans have a long history. It is estimated that more than 10% of the thousands of plant species known to have medicinal uses. Drought causes plants osmotic imbalance and inhibits plant growth and productivity. The aim of this study was to investigate the effect of drought on some biochemical and physiological trait of Lippia citriodora genus of verbeneceae family. Drought stress induced by polyethylene glycol (PEG) with different concentrations, 0%, 5%, 10%, 20% and 25%. Result showed that FW (Fresh Wight) and RWC (Relative Water Contents) decreased significantly under drought stress in comparison to control. Root length not show significant changes under drought stress.At low levels of PEG Pigment content under drought stress increased significantly while reduced significantly in high level of PEG. Under drought stress, protein, proline, MDA (malondialdehyd) and hydrogen peroxide (H2O2) contents have been increased significantly. The antioxidant enzyme activity increased under drought stress when compared with control plants. Under drought stress Decreases in some parameter such as FW and RWC indicative sensitivity of this plant to stress on the other hand it responses to stress by increases in some compounds such as prolin, H2O2 and also increases in antioxidant enzyme activity.

The comparison of different Robinia pseudoacacia organs regarding amount of deriving nitrogen from biological nitrogen fixation process. Black locust (Robinia pseudoacacia L.) is one of the most famous plant species in the world, regarding nitrogen fixation ability. It is widely used in reforestation projects in the world. The main question of this study was that, whether the different parts of Robinia (i.e. roots, stems and leaf) derived same proportion of their required nitrogen from biological nitrogen fixation process.The collected seeds of Robinia were planted in similar greenhouse conditions. After 2 months, the seedlings of Robinia were inoculated with a suspension of mixed Rhizobium. At six months from the start of the greenhouse trials, the seedlings received the equal amount of (NH4) 2 SO4 (100 cc) contain 11.03 N15. After one week, they were harvested and separated into leaves, stems, and roots. The samples were dried, weighed, and the N15 excess was measured. The N15 excess concentration was used as an index for comparison the amount of nitrogen derived from biological nitrogen fixation for each plant organs. The results did not show any significant difference amongst leaf, stem and roots of Robinia in terms of the nitrogen derived from biological nitrogen fixation procedure. Therefore, the most accessible part of plant (i.e. leaf) can be used for calculating the nitrogen proportion of nitrogen derived from biological nitrogen fixation process.

A major challenge for industrial microalgae production is cultivation problems.Photobioreactors with different volumes are one of the systems applied for microalgal mass cultivation. Following species identification, design and optimization of a photobioreactor are necessary. In the present study, growth (doubling time, cell density and dry weight) and chlorophyll a content of Nannochloropsis oculata were investigated using Guillard (f/2) and Walne media for two periods of 15 days. Cells density, chlorophyll a and dry weight of microalgae grown in both media were measured with three replications. The results showed significant influence (P<0.05) of Walne than Guillard media from days 3 to 10, and from 2 to 15 (except day14), respectively. Cell density from days 10 to 15 showed significant influence (P<0.05) of Guillard than Walne media. While dry weight (mg) increased in both media until day 6, Walne medium displayed higher weight increase than Guillard medium from days 6 to 11. Conversely, Guillard medium showed greater weight elevation than Walne medium from days 11 to 15. Specific growth rate (SGR) averaged 0.3 and 0.25 d-1 at Walne and Guillard media, respectively. N. oculata displayed a minimum doubling time of 1.5 day at Walne medium during the first 3 days of cultivation. Based on these results, excellence of Walne medium observed.

In this project stem anatomical structure of 61 populations of 6 annual Polygonum L.species of Iran, comprising P. aviculare, P. arenastrum, P. polycnemoides, P. patulum P. argyrocoleon and P. olivascens were studied. Polygonum is a genus with palisade mesophyl under stem epidermis, containing oxalate calcium crystals and a specialized xylem tissue. Stem anatomical structures are compared between species. Species relationships and affinities are discussed due to the results of statistical analysis. Results indicated the difference between fiber patch numbers, vascular bundles, stem average diameter, and stem protruding shape in cross sections, stele diameter and general outline of stem cross sections. P. aviculare show a great variation in studied species of this genus in Iran. Based on observed differences identification was done for species.Results indicate that stem anatomical characters can provide some diagnostic values for species delimitation in some morphologically similar species of this genus in Iran.

Pomegranate is one of the most important fruit crop in Iran which its demand was increased because of its pleasant taste and its medicinal properties. Almost all of pomegranate consumers prefere soft-seeded fruits. Current research was designed to investigate the effect of two palnt growth regulators and streptomycin on improving fruit and seed quality of pomegranate. Indole-3-acetic acid (IAA) (10mg/l), kinetin (Ki) (10mg/l) and streptomycin (SM) (200mg/l) were sprayed at two growth stages of fruit set and four weeks after that on pomegranate trees cv. Malase Yazdi. Then, at harvest stage, effect of these treatments on edible portion of fruit, weight, size, water content and fiber aggregation in seed and chemical properties of fruit were studied. Results indicated a significant increase in maturity index of treated fruits in comparison to those of control. Plus, higest total phenolic content was observed in SM treated fruits.Application of IAA at fruit set stage and Ki both at fruit set stage and four weeks after that increased edible portion through increasing size and weight of aril. Furthermore, application of SM especially at fruit set stage and application of Ki at fruit set stage significantly reduced lignification of seed. The results were demonstrated that Ki and IAA could increase fruit quality of pomegranate cv. Malase Yazdi, however, SM at beginning of fruit set stage reduced fiber aggregation in inner layer of seed, in addition to fruit quality.

Economical consumption of natural plant resource always depended to the wise plan with dual policy of maximum harvest and minimum damage on plant survival and growth. In this respect, the white Astragalus (Astragalus gossypinus fisher) reported as an invaluable natural plant with several advantages such as high productivity and secretion of considerable quality of tragacanth gum currently are facing severely threatened as a result of habitat destruction, over-harvesting and a few additional environmental as well as man-made factors. In general several key factors influence quantity and quality of Production of gum tragacanth in different climate and soil condition and characteristics which need fitting suitable model for identification of related factors to maximize end point production amount. For this known motivation, the purpose of the present study was the determination of the linear model of gum production in As. gossypinus according to the soil habitats in Isfahan Tiran and Karvan. For this purpose the plants of introduced species have been harvested in different years with different ages, therefore the gum sample was taken along the transects at each vegetation types according to soil properties and the data were analysis by using SPSS software (method of Enter) to regression equation and modeling. The result of the study showed the existence of high various coefficients about game production in different regions. We demonstrated that production and storage gum in the plant require different time according to soil characterizes that to be ignorable.