مجله پژوهشهای گیاهی (زیست شناسی ایران)
سال بیست و هفتم شماره 4 (زمستان 1393)

This research was carried out in Asalem/Guilan province where، Acer velutinum show preferred establishment and distribution. In this research، soil chemical and physical properties and topographic factors effected on establishment and distribution of Acer velutinum was investigated to determine the most important ecological factors. Using tree type and topographic maps، the sampling plots were taken randomly in appropriate distribution sites of Acer velutinum. In each sample plot، aspect، slope، elevation، tree species، diameter of each tree and soil samples were taken and then the most important soil properties were analyzed. Regeneration of tree species was also taken in center of each main plot in micro-plot. The results showed that C، N and water holding capacity (WHC) have positive and significant correlation with distribution of Acer velutinum and among topographic factors، north aspect also showed this correlation. C، P، WHC، sand content and elevation showed positive and significant correlation and Ca، Mg showed negative correlation with regeneration of Acer velutinum. The final results of this research showed that productive sites with fertile soils are the main factors for establishment and distribution of Acer velutinum.

Determination of spatial pattern of trees in forest stands, as one of the most important characteristics of stand structure, is essential in tending, reclamation and management programs. This research was carried out in Rikhalan forest of Marivan, Kurdistan province, to identify the spatial pattern of sprout-clumps of oaks. Three quadratic plots with different areas of 0.5, 0.75 and one ha with same origin point were considered. All of trees were numbered and their origin as well as the smallest and largest crown diameters was measured. Coordinates of all trees were determined using azimuth-distance method and spatial point pattern was analyzed by Ripley's K-function. Based on results, the main species was Brant`s oak (Quercus brantii Lindl.) and the tree density was 111 per ha. The mean values of crown diameter and crown area were 5.6 m and 28.2 m2 in one ha plot, respectively. Analysis of data by PAST software showed that the spatial pattern of Brant`s oak was cluster type. Furthermore, the suitable plot size to study spatial pattern in the studied stand was 0.75 hectare which is recommended for similar stands.

The study of reproductive organs development is important in taxonomy and developmental biology. In this research, developmental process of ovule and pollen grains were studies in Anthemis odontostephana. According to results of this study, anthers are tetrasporangiated type and development of anther wall is of dicotyledonus type and composed of one-layered epidermis, an endothecium, one middle layer and tapetum. ¬Tapetum layer indicated high polyploidy level that necessary for metabolism and it is of the secretory type. Microspore tetrads are tetrahedral, in the main, and tetragonal in some cases. Pollen grains are three colpated with echinated sculpturing, at the shedding time. The size of some microspores increased it seems that they showed Nemec phenomenon. Presence of asteroid crystals in the cells of endothecium layer and connective tissue is the characteristic of this species. Ovule is anatropous, unitegmic and tenuiucellate. Cell division of megaspore mother cells is of both longitudinal and transverse type and resulted to form linear, T-shaped or massive tetrads. Embryo sac development is of the Polygonum type and antipodal cells increase up to 6-8 and their nuclei become polyploidy. The polar cells are migrated toward egg apparatus and combined prior to fertilization. Formation of ovate to polygonal crystals is the characteristic of this species.

Drought is one of the most important yield limiting factors for canola (Brassica napus L. cv. Okapi). In this research, we studied effect of selenium (Se) treatment on increasing drought tolerance in canola plants under field and greenhouse conditions. In the field experiment, plants were treated with Se (5 and 10 g ha-1 as sodium selenate) two times, as both soil application and leaf spraying. In greenhouse grown plants, Se was added (at 100 μg plant-1) to the growth substrate (perlite) directly. In the field grown plants, vegetative biomass and seed yield of drought-stressed plants were significantly increased by Se application as leaf spraying. Results of the greenhouse experiment showed that, Se ameliorated growth reduction of drought-stressed canola plants through increasing plants ability for water uptake. Formation of more fine roots and increasing photosynthesis that provided more soluble sugars as osmoticum for supporting water uptake, were mechanisms for this response.

Study of tobacco plant transformed with AtNRT2.1 gene, which belongs to HATS ‎‎(High Affinity Transporter System), indicated that using of wet and dry weight ‎measurement is not sensitive to show the differences between transgenic tobacco ‎plants in comparison with wild types. Thus, in this study, chlorophyll a ‎fluorescence measurement, a more sensitive method, was performed. For this ‎purpose, the plants were grown in hydroponic medium, and nitrate was applied in ‎low concentration (in HATS activity range). Then fresh weight, relative ‎chlorophyll content and chlorophyll a fluorescence and performance index (PIABS) ‎were measured. Results showed there is no significant difference in fresh weight ‎and relative chlorophyll content of wild type in comparison with transgenic plants. ‎It seems that significant difference in performance index (PIABS) of transgenic ‎plants in comparison with wild type plants in 4h after commencement of ‎experiment is due to better absorption of nitrate by over expression of transformed ‎gene at first hours of experiment. ‎

Saffron (Crocus sativus l.), member of Iridaceae which was used as spice and also in medicine. An investigation was set up in order to select suitable samples to improve saffron production. The activities and isoforms of antioxidant enzymes which were affected on H2O2/O2 ratio, that represented the potential of organogenesis was carried out by using electrophoresis and five different segments of saffron immature flora. The number of peroxidase isoforms which were specific-tissue and developmental stages that consumer of H2O2 and Superoxide dismutase which produce H2O2 from superoxide showed high ratio in ovary and low in perianth segments. Catalase was repressed by higher but responses by lower level of H2O2, acts versus peroxidase. The other Three enzymes, Polyphenoloxidase is specific-growth and represent defense system, Malatedehydrogenase, showed relationship between organs and their growth and also produced H2O2 and Estrase was specific- organization of tissue all gave us useful information to select right segments for our propose.

In order to study the impacts of usage of bio and chemical phosphate fertilizer on growth, yield, yield components and essential oil of Fennel, a field study conducted during spring planting season 2010 at station research farm of medicinal plants at Shahed university. Bio fertilizer treatment contains 3 levels of nitrogen fixer mycorhizae (no inoculation, inoculation with Pirimospora indica and inoculation with Sabacina vermifera) and phosphate solubilizing microorganism (Pseudomonas putida bacteria) in two levels (with and without inoculation with microorganism) and 3 levels of chemical phosphate fertilizers (consisted of 0, 50 and 100 kg ha-1 of P2O5). The impacts was evaluated in split plot based on randomized block design with three replications. At each replications a chemical fertilizer (NPK) control plots were considered as a comparison to bio fertilizer application. Results showed that all measured traits in compounds phosphate solubilizing microorganism and nitrogen fixer mycorrhizae were higher than other treatments. So, applied treatments have a significant influence on grain yield with the rate of 516 kg ha-1, biological yield with rate of 4.125 kg ha-1, compound of umbels per a plant with number of 512.9, harvest index with rate of 12.5% and essential oil yield with rate of 126.63 lit ha-1.

Male and female individuals of dioecious plant such as Pistacia atlantica desf are difficult to recognize from each other without sexual organs e.g. flowers. In this study for identification of males and female plants used of the morphological variation of 180 leaves from 60 individuals of P. atlantica in Arasbaran frosts of North West Iran. Several the quantitative and qualitative characteristics morphologic were compared by spss softwar, the results of morphological analyses show that leaf length, leaf area, leaf width, terminal leaflet width, the presence of alternate leaflet and opposite leaflet and presence of triplet leaflet are in males and femals different significantly from each other. Discriminate analysis proved accuracy of distinction in individuals about 70.6% using morphological traits. In this study suggesting that application morphological characteristic of vegetative organs e.g. leaf can be helpful in sex differentiation in dioecious plant species at earlier stages before sexual reproductive organs appearance.

Juniperus excelsa is one of the native and valuable Gymnosperm species of Iran belonging to Cupressaceae family. It distributes considerable parts of Irano-Turanian region. According to available problems in natural regeneration and costly process of juniper seedlings production in nurseries an experiment was carried out to investigate effects of culture bed on morphological and physiological characteristics of transplanted one year’s junipers seedlings. Treatments include three culture beds (soil A:16 soil+8 sand, soil B: 20 soil+ 4 dung, soil C: 20 soil+ 2 dung+ 2 sand(usually used in nursery)). Experiment design was completely randomized design. Each treatment included three replicates and each replicate include 20 seedlings (in total 180 seedlings). The results showed that treatments had a significant effect on survival, root biomass and root to shoot biomass ratio. soil A (16 soil +8 sand) was considered to be the best media to provide higher survival and seedling quality.

Satureja khuzistanica Jamzad is a native plant that is dispersed throughout southern Iran. This plant has been used as analgesic and antiseptic medication among the inhabitants of southern parts of Iran. Carvacrol as the main component of the wild S. khuzistanica (≤90%) has been found to have significant antioxidant properties. In this study, the shoot cultures of Satureja khuzestanica in LS medium were affected by different concentrations of FOS and MEV (0, 10, 25, 50, 75 and 100µM) for 21 days. Then the Carvacrol content in different treatments was assayed by HPLC method. The level of 1-Deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) gene expression in concentrations above and optimal concentration (75 µM) from zero to 100 hours was monitored by Semi-quantitative RT-PCR method. Our results showed that Concentrations in some inhibitors can have an influence on DXR expression and carvacrol contents. The changes observed in carvacrol can be considered as a result of different levels of DXR expression.

Phenology studying in the rangelands is important for adjustment of grazing programs, optimal and proper utilization from rangelands plants and prevent from early and untimely grazing and recognition of palatability and nutritional value of plant species in different stages. So in order to determine the timing of entry and exit of livestock to and from rangeland this study was carried out in a semi-steppe rangeland in Alamut of Ghazvin province, 100 km North eastern of Ghazvin five years from 2006 to 2010. The two studied wheat species was Bromus tomentellus and Festuca ovina that has moderate palatability for livestock. From each species 10 basic selected. So information of phenology plant noted in 2 stages: growth stage in every 15days and reproductive stage in every 7 days. The time of the start and end of the species growth varied in the different years in this species affected by rainfall and temperature, and length of period in the rainy years is longer than drought periods. Generally their flowering time is the last week of Ordibehesht (April) to the first week of (May) and it lasts for 3 to 6 weeks depending upon the dryness status or wetness position of the year. In the last week of May, we do the seeding phase.

Tecomella undulate (Roxb.) Seem. is deciduous or nearly evergreen tree that is highly valuable due to showy and beautiful flowers, resistance against extereme temperature and drought, stabilizing of shifting sand dunes, medicinal properties, wood production and so on. In this study, morphology and anatomy of flower was surveyed. The inflorescence is raceme-cyme; the perianth is pentamerous and adnate; the calyx is persistent, regular and cup (bell)- shaped. The corolla is tubular-cup shaped, bilobate and irregular in the top. The androcium contains four functional and almost didynamous stamens and one staminode. The anthers are dorsifixed, at maturation apifixed and pollen sacs seem somewhat biloculate due to grown placentoid. Epidermal celles are tangentially elongated and function as endothecium. Tapetem is secretory type. Ggynoecium is bicarpillary, syncarpous with bilocular and elongated ovary, long and open style and bilabiate stigma. Ovary is located on well-developed nectary disc and has many anatropous, unitegmic; tenuinucellate ovules. Flowers open in the morning and are protandrous, as the stamens dehisce after their opening but stigmas are receptive in the afternoon. Pollen grains are heteromorphous specially dimorphous, tricolpate with reticulate sculpture. No seeds form in this species in under study areas.

The changes in growth, and content of proline, MDA and phycobiliproteins and the involvement of the antioxidant enzymes in relation to salt stress tolerance were investigated in Nostoc ellipsosporum and N. piscinale. Both microalgae were grown in BG-11 medium in the presence of various concentrations of NaCl (0, 50 100, 150, 200, and 250 mM) and. Both species showed an increase in dry weight under stress. N. ellipsosporum was more tolerant to NaCl stress than that of N. piscinale and N. ellipsosporum obtained more biomass under salinity stress in comparison to N. piscinale. Salt stress induced catalase (CAT), peroxides (POX), polyphenol oxidase (PPO) and superoxide dismutase (SOD) activities in N. ellipsosporum and N. piscinale after 9. Salinity treatment significantly induced increase in phycobiliprotein in N. piscinale and in N. ellipsosporum. This increase was prominent in N. ellipsosporum than that of N. piscinale. Moreover, the variability of phycobilisome size was also examined. The size of phycobilisomes can be usually represented by the ratio [PE + PC/APC]. The size of phycobilisomes (by elongation of the phycobilisome rods) increased significantly under salt stress.

During 2009-2011 some of the ruderal and segetal areas inside of Hamedan city and its suburb (to 30 km of Hamedan) involving some of the farms, gardens, green spaces, waste lands and also margin of terrafic regions (streets and superhighways) were compared based on ecological-floristical view in relation to presence and dispersal of Anchusa L. genus. Two species and one sub species from this genus already have been observed and collected from studied areas, Anchusa italica Retz. (with two varieties, A. italica var. italica and A. italica var. kurdica) and Anchusa strigosa Labill. species and Anchusa arvensis (L.) Bieb. subsp. orientalis (L.) Nordth.sub species. The most dispersal belongs to A. italica with its two varieties in environments with H3 (β-euhemerob) and H4 (α-euhemerobe) hemeroby degrees. A. arvensis subsp. orientalis was mostly observed in agricultural areas, with relatively a few numbers, in two blue and white colors. A. strigosa species with H3 (β-euhemerob) hemeroby degree, was observed with highly limited dispersal only in one region, outside of the city.

The aim of this study was to evaluate herbaceous species diversity in a pure and an untouched beech forest. For this purpose, 170 ha of Roudbar forest of Guilan province were investigated. With using biological indices, numerical values of species diversity, richness and evenness calculated and the results were compared to similar studies. Results showed that values of indices obtained are less than other studies. Causes of this problem are a lot of litter depth, high canopy percentage, being the study area at high altitudes and the lack utilizing in the region due to lack of road networks. The evenness amount had more effective than richness in diversity amount. Abundance distribution curve of species followed log normal model.The most cover percentage was related to Bromus benekenii species that is an exotic species and is considered a serious threat to biodiversity in the region.

In this research the first experiment was performed in order to evaluating effect of various concentrations (20, 40, 60, 80, 100 % by volume) of vermicompost extract on some indices of seed germination and seedling growth of Nigella sativa in petri dishes. In the second experiment the effect of solid vermicompost substitution with 4 levels (0, 25, 50, 75% by volume) on the emergence and vegetative growth of plant was investigated in a pot experiment. Results showed that 20, 40% concentrations of vermicompost extract increased germination capacity, germination value, germination max value and length of root, shoot and vigor index. Also 25 and 50% substitutions of solid vermicompost increased emergence indices and length, dry and fresh weight of root and aerial parts, content of a, b, total chlorophyll and carotenoid in 3 old month's plants significantly as compared to the control. But high concentrations of vermicompost or its extract reduced these parameters. Thus, the effect of vermicompost on seed germination and vegetative growth of plant is dependent on concentration.

This study has investigated the effects of the different levels of Salicylic acid(SA) on the total fresh weight, Chl(a, b, and total), prolin, total soluble protein, soluble and insoluble sugar under stress of cadmium(Cd) in the plant of the wheat(Triticum aestivum L. cu. Zarrin). The seedlings received pretreatment of salicylic acid (0, 10-4 and 10-3M) and treatment of Cd(0, 25 and 50µM). The results showed that the total fresh weight at 50µM of Cd in the Cd treatments without SA had a significant increase by comparison with control. At SA treatments without Cd, the concentration of Chl a and the total Chl at 10-4M from SA increased. At Cd treatments without SA in 25µM of Cd the amount of the root prolin by comparison with control increased whereas the amount of the leaf prolin decreased. At the lack of Cd with increasing SA, the amount of the leaf prolin by comparison with control decreased. By increasing the concentration of SA in the lack of Cd, the level of the root protein increased. In the absence of SA with increasing Cd, the amount of soluble sugar of the root and leaf decreased. In the SA treatments without Cd, the amount of the soluble sugar of the root was decreased. With the lack of SA within increasing Cd, the amount of insoluble sugar of the root and leaf in 25µM of Cd decreased. In the SA treatments with the lack of Cd, the amount of insoluble sugar of the leaf increased.

The late stage of decomposition process identified by that when decomposition and degradation of lignin had been occurred, i.e. at about 1 year after the incubation. The regulating factors for degradation of lignin, and thus of litter, in late decomposition stages are little known and we know very little about how they vary among litter species and sites with different climatic and edaphic conditions. Therefore, this study was done inorder to determine whether the control of lignin decay, and thus of litter mass-loss rate, by N, Ca and Mn in leaf litters of Norway spruce (Picea abies (L) Karst), Alder (Alnus subcordata C.A.Meyer) and Maple (Acer velutinum Boiss.) in pure and mixed Norway spruce sites after 400 day in lajim region. The results showed that decomposition rates of litter species exclusive of Maple, in mixed Norway spruce site were significantly higher than pure Norway spruce site. In the pure Norway spruce site decomposition rates of litter species were positively and significantly correlated with Mn and Ca concentrations, but had not significant correlation between Mn and Ca concentrations with lignin concentration. In the mixed Norway spruce site decomposition rates of litter species had significantly positively and negatively correlated with N and lignin concentrations respectively. Also in this site, there was negatively and significantly correlation between Ca and lignin concentrations. In relation with litter type, exclusive of needle litter, that Nitrogen amount is important regulating factor, nor of descriptive and qualitative factors (N, lignin, Mn, Ca) had not effect on the decomposition in late stage.

For achievement tosustainable development and conservation of natural ecosystems and their biodiversity,study on topographic factors and their effects is necessary.Regarding to topographical condition of Arasbaran forests of Iran,slope is an important ecological factor controlling many other dependant variables.So the inventory grid was designed by a random-systematic method with dimension of 300×300 meter and 160 sample circle plot with 314 square meters area were taken in Arasbaranforests.Shrub and arborous species were measured in main sample plot.Species,the percentage of coverage crown and the number of basis were considered as the measurement standards of plant coverage.Grassy species were measured in micro sample plots each with3.14 square meter.In micro sample plots,species and the percentage of the grass coverage were both determined.Site slope weredividedtothree classes including(0-25,25-50,and over50percent)in order to determined the biodiversity of plant species in different slope classes,and then indices of Margalef,Menhinick,Modified Nee, SmithandWilson,Simpson and Shanon-Wiener was calculated in each class.To determine the difference between slope classes we used one-way variance analysis and multi range comparing Duncan test.The results show evenness index of the range of plant do not have significant impact, however, its effect on the richness and heterogeneity index is a mean.Also the results showed that the index of species richness has a significant role in increasing biodiversityof region studied with increasing slope.Coefficient of variation toidentify the best indicator of the statistics and Pearson correlation coefficient was used.The result showed that to measure of richness,Margalef index,to measure of the evenness,Modified index and to measure of the heterogeneity,the Shanon-Wiener index,are the best indicators.

Every year for different reasons, more lands turn into salty soils, therefore we can’t rely on their production cycle and utilization. So the first step to repel this problem is recognition of regions that are salty such as Hoze Soltan lake. According to the floristic study in this region,47 plant species from 42 genera belonging to 21 families were collected and determined. The richest family in the studied area is Chenopodiaceae (% 29.79), considering life form spectrum, the highest proportion of life forms belonged to therophytes constituting (%51.06) of the biological types that showed dry and steppe climate, the most tolerant halophytes is Halocnemum strobilaceum and the most sensitive halophyte is Artemisia sieberi. To determine soil characteristics such as soil texture, pH, EC, anions and cations in different plant layers, some profiles about 1.5 km around the lake were installed. By soil sampling in the depths of (0-20) cm and(20-60) cm, the soil analysis was done. The research findings represent that the soil categorized in salty and alkaline and from surface to depth the amount of clay and alkalin is increased but salt decreased. The most important factors in plant distribution are salt and soil texture.