جستجوی مقالات مرتبط با کلیدواژه « ارتفاع » در نشریات گروه « باغبانی »

Turfgrasses, as one of the important components of urban landscapes, have played a vital role in this regard. However, the main problems of turfgrass development are the cost of turfgrass seeds, maintenance costs such as moving, as well as the high water requirement in arid and semi-arid regions. Thus, the reduction of lawn culture in the landscape is one of the decision has taken in parks and green spaces organization of Tehran, Isfahan and even Mashhad. For over ten years, researchers have been looking for alternatives to conventional grass lawns to reduce the high cost of maintenance especially irrigation cost in urban landscapes. According to many researches, one of the potential ground cover alternatives that might be used instead of turfgrass is White Clover. Clover (Trifolium spp.) from Fabaceae family is a genus of about 300 species.

The aim of this experiment was to compare three common turfgrasses with two clover varieties as turf replacement to reduce landscape maintenance cost specially moving cost. So, some growth and qualitative factors of clover lawn: Trifolium repens var. Calway and Trifolium repens var. Pipolina (micro clover) and three turfgrasses of Festuca arundinacea L. and Lolium perenne L. and commercial sport turf mixture (from NAk-Nederland Ltd.) were compared together. This research was conducted in randomized complete block design with three replications in the research field of the Department of Horticultural Science and Landscape Engineering‚ Faculty of Agricultural‚ Ferdowsi University of Mashhad‚ Mashhad‚ Iran, during 2016 and 2017. The site (59º 38′ E and 36º 16 ′ N; elevation 989 m) is located in an arid and semi- arid region with mean annual rainfall 233.8 mm and long term averages of maximum and minimum temperature are 22.5 ºC and 9.3 ºC‚ respectively. Turfgrass plots were established by directly sowing the seeds in April, 2016. The planting rate of the seedling considering their pure live seeds (PLS) were 45 g.m-2 for Lolium perenne, 34 g.m-2 for Festuca arundinacea, 6.5 g.m-2 for Trifolium repens, 5.5 g.m-2 for micro clover and 39 g.m-2 for commercial mixture of sport turf. The plots were 1 m2 (1m×1m) in size and were prepared after plowing and leveling the soil. The seeds were hand sown and covered with a thin layer of leaf compost and sand.

According to the results in the first evaluation of emergence percentage, Lolium perenne had the highest emergence percentage. After 36 days from culture, all plants had 92-98 % coverage which did not have any significant difference among grasses with clover lawns. In terms of density, uniformity and weed density, there was no significant difference between the studied plants. In the other hands, white clover showed the best quality after clipping in both years. At the point of growth index, which have done in this experiment by measuring height and dry weight of clipping, grass lawns had the higher growth index in compered to clover lawn in both years. Festuca arundinacea and Lolium perenne had the highest growth index and white and micro clover had the lowest growth. Also, with air warming, Festuca arundinacea became dominated plant in height and clipping dry weight. In July, Festuca arundinacea produced the highest clipping dry weight by 40 gr.m-2, Lolium perenne (19.52), commercial sport turf (15.68), white clover (6.24) and micro clover (0.36) gr.m-2.

One of the problems of landscape is reduction of maintenance costs such as mowing. So, the low growth of white and micro clover is a positive factor in reduction of the moving costs than turfgrasses. Also, the coverage and proper density of clover lawns are similar to grass lawns and did not have a significant difference with them. The character of low growth can be effective in reduction of irrigation costs in white and micro clover, which requires more research and examination in future. This is a positive point in the white clover and micro clover that do not need to move or cut every months. Almost, clover moving is recommended for removing their flower. Therefore, it is recommended to use white and micro clover as a replacement with less maintenance costs in landscape. Finally, the results of cultivation of grass and clover as monoculture in this study can be used to produce clover-grass mixtures suitable for the climate of our country (arid and semi-arid regions), instead of importing turf mixtures from European countries.

The phytochemical and biological properties of medicinal plants depend on the climatic conditions of the area under development, the growth stage, genetic factors and other factors. Therefore the study of the wild flora in the geographical areas with different climatic conditions is important. It has been proved that the extract of Epilobium has high antioxidant capacity, which is associated with a high concentration of flavonoids content. Studies on five species of Epilobium genus (E. parviflorum schreb., E. roseum schreb., E. tetragonum L., E. montanum L., E. angustifolium L.), had shown that E. parviflorum had the highest antioxidant capacity among studied species. The occurrence of E. parviflorum in wide range of altitudinal zones in Iran makes it as ideal species to study the variation of antioxidant capacity among ecotypes. The present study aims to screen Epilobium parviflorum ecotypes (n=16) of Iran in terms of antioxidant capacity (AOX).

Total phenol content (TPH), Total flavonoid (TFL), antioxidant capacity (AOX) and anthocyanin content (ACY) were measured by Folin- Ciocalteu, flavonoid-aluminum chloride (AlCl3), Ferric reducing antioxidant power (FRAP) and the differential PH methods, respectively. Regression analysis was used for studying the relationships between antioxidant capacity, altitude and latitude. The Pearson correlation coefficient was used to determine whether there is a linear relationship between variables.

There was a high correlation between total phenol content and total flavonoid in ecotypes (r = 0.7, P = 0.002, n = 16). There was a positive and significant correlation between AOX content with TPH (r = 0.71, P = 0.002, n = 16) and also between AOX with TFL (r = 0.73, P = 0.001, n = 16). According to several studies, high antioxidant capacity has been attributed to high concentrations of flavonoids and phenols, which is consistent with the results observed in this study. The results also showed that the Iranian E. parviflorum ecotypes had considerably TFL, TPH and AOX content as compare to previous reports on E. parviflorum (in other country) and also other Epilobium species. Principal component analysis showed that the two main components explained 87.87% total variation. The high contribution of the two first components suggested a considerable correlation between three phytochemical traits, the contribution of the first component alone was 62.13% and the portion of the second component was 25.74%. In the first component, TFL, TPH and AOX were with coefficients of 0.78, 0.77 and 0.88, respectively. The high contribution of the two first components had a significant relationship between three phytochemical traits. The ecotypes of E. parviflorum were clearly separated based on the first principal component. Ten ecotypes had a correlation with the first main component (PC1) shown by TFL, TPH and AOX. Among them six ecotypes had a positive correlation (r> 0.6) and 4 ecotypes had a negative correlation (r> 0.6) with the first main component (PC1). Thus, out of the 16 ecotypes of E. parviflorum in Iran, six ecotypes including EPP3, EPP6, EPP8, EPP10, EPP13 and EPP9 had the desired content of TFL, TPH and subsequently antioxidant capacity, most of which belonged to the Zagros and crossroad of Zagros and Alborz mountains. The ecotypes that did not have the desired content of TFL, TPH and AOX (negative correlation with the first main component, PC1) mostly belong to the Alborz Mountains. The highest levels of TPH, TFL and AOX capacity were observed for the Sangan ecotype with values of 1761, 32.64 mg/g DW and 93.50 mM/g DW, respectively, and the lowest was observed in Kaleybar ecotype. Out of 16 ecotypes, 6 ecotypes had the desired content of TFL, TPH, and subsequently AOX, most of which belonged to the Zagros and crossroad of Zagros and Alborz Mountains. Regression analysis showed no relation between AOX capacity with altitude (R2 = 0.04) and also with latitude (R2 = 0.14).

This research is the first study that screens AOX capacity by including multiple ecotypes (n=16) from E. parviflorum species to evaluate intra ecotypes phytochemical variation for E. parviflorum. We found positive and significant correlation between TFL, TPH and AOX. We did not find any significant correlation between TFL, TPH content and AOX capacity of E. parviflorum with altitude above sea. Our results also showed Iranian E. parviflorum ecotypes (especially Sangan ecotype, EPP10) have considerably TFL, TPH and AOX capacity compared to previous reports. The results of this study indicate that there is a remarkable variation among Iranian E. parviflorum ecotypes for the studied traits, which can be used to carry out breeding programs and protection of germplasm.

Horsemint (Mentha longifolia L.) is a valuable medicinal and aromatic plant belonging to Lamiaceae family. It was reported that the contents and composition of perceived pharmacological properties varied significantly among populations. The genus Mentha L. (Lamiaceae), is widely distributed in all continents (except in South America and Antarctica). The systematic of the genus is not very elucidated because of the strong morphologic variations, levels of ploidy (2n = 2x = 24 to 2n = 6x = 96), and hybridizations intra- and interspecific (or between spontaneous and cultivated forms). M. longifolia or horsemint is a fast-growing and perennial herb which cultivated in all regions. The species possesses antimicrobial and antioxidant properties. The antimicrobial properties of the essential oils can be attributed to the presence of pulegone, menthone and neomenthone because they can destroy the structure of different polysaccharides, fatty acids and phospholipids by altering the permeability of the cell membrane and destroying the bacterial wall. The essential oils of horsemint are said to be cyclohexane and aromatic, and pulegone is the main compound of these oils has a definite aroma in the range of intense to spicy mint. The effects of environmental conditions on the plant growth and development, reproduction and distribution are well known in plant ecology. Many studies have been carried out about the relationships among plant chemical contents, biological activity and environmental variables in the natural and cultivated plant species. This information has been used to determine the medicinal value and economic importance of plant products.

In this research, the effects of six habitats with different altitudes (habitats of Amol city) on some morphological and biochemical characteristics of horsemint plants were investigated in a completely randomized design with three replications. This study was done to compare the amount of pulegone, total phenol, total flavonoids, antioxidant activity, chlorophyll a, chlorophyll b, total chlorophyll, carotenoid and also morphological features of horsemint such as number of leaves per plant, number of branches per plant, number of flowers and number of nodes.  For antioxidant properties using DPPH method in 517 nm wavelength, total amount of phenol using Folin-Ciocalteu method in 765 nm wavelength and the total amount of flavonoid were done using the aluminum chloride method in 415 nm wavelength and they were measured by spectrophotometer. Essential oil was extracted from dried aerial parts using distillation by Clevenger apparatus for 3 hours. Gas chromatography (GC) was used to measure pulegone.

The results showed that the altitude and ecotype significantly affecting the growth and biochemical characteristics of horsemint plant. The highest number of leaves (25) and the shoots (27) of horsemint were obtained in the Gat Lash region with 2000 meters and Siozmin with 1850 meters above sea level, respectively. Gat Lash and Siozmin had the highest and lowest content of photosynthetic pigments, respectively. Although there was no significant difference between the content of phenol and flavonoids in different habitats, the highest rates were observed in the Pardemeh and Gat Lash habitats. The results showed that the highest and lowest oil were obtained from ecotypes of Gat Lesh with 2000 meters and Vash Verin with 2300 meters above sea level, respectively. As the height increased, the amount of pulegone was also increased in the leaves, so that the highest amount of pulegone was found in Pardemeh )6069 ppm) habitat by 2600 meters above sea level.

Generally, for obtaining the highest essential oil content and pulegone, the best ecotypes were Gat Lash and Pardemeh habitats, respectively. Due to the importance and usage of secondary metabolites in the human life, investigating the relationship between environmental conditions with the production and accumulation of secondary metabolites in plants can be very useful. Our results showed that the climatic conditions had a significant effect on the morphological characteristics of the horsemint, thereby increasing or decreasing the essential oil. In the present study, the best habitat for the highest pulegone was Pardemeh habitat but the habitat of Gat Lash could be a suitable habitat for domestication and cultivation of this plant because of its higher essential oil yield and relatively good pulegone content. For this purpose, it is recommended to study different habitats of this species in other parts of the country for finding the best ecotypes.

Drought is one of the most detrimental abiotic stresses for turfgrass growth across a wide range of geographic locations. Most cool-season grass species are not well adapted to extended periods of drought, particularly during summer months. Decline in turf quality caused by drought stress is a major concern in turfgrass culture. Therefore, developing management practices for improving drought resistance of turfgrasses has become essential in arid and semi-arid regions, especially during water use restriction. One strategy to improve plant drought resistance is to promote drought avoidance by reducing water loss during drought, which may be achieved by slowing growth rate of shoots and lowering leaf area canopy to reduce demand for water. Application of growth regulators is one of the methods for increasing resistance of plants to biotic and abiotic stresses. Trinexapac-ethyl (TE) is one of the most widely used PGRs in the management of cool-season and warm-season turfgrass species. TE absorbed quickly by foliage and slow cell elongation through inhibiting of converting one form of gibberellic acid (GA20) to another (GA1). Most studies conducted under non-stressed conditions found that TE application increased chlorophyll content, turf quality, turf density and reduced shoot extension rate. We hypothesized that TE may influence plant tolerance to drought stress. Limited available data─ as reported in the above referred studies─ suggest that TE application may be beneficial for plant tolerance to stresses, but the effectiveness varies with turfgrass species, dose and duration of TE treatment, and type of stress. The main aim of this research is to evaluate the effect of Trinexapac-ethyl on increased resistance to drought stress in wheatgrass.
Wheatgrass (Agropyron desertorum L.) was used in this study. This study was conducted in field conditions at Isfahan University of Technology, Isfahan, Iran.. Wheatgrass native seeds (Agropyron desertorum L.), collected from the turfgrass research farm at Fereydan, Isfahan, which were cultivated hand broadcast in plots (3m × 2m) with seeding rates of 30 gm–2. A factorial experiment based on randomized complete block design (RCBD) with three replications was conducted for TE (Primo Maxx; Syngenta Crop Protection, Inc., Greensboro, NC) and drought stress. Treatments involved three levels of Trinexapac-ethyl growth regulator (0, 0.25 and 0.5 kg/h) and two levels of drought stress (with irrigation and without irrigation). After planting, the plots were irrigated to maintain soil moisture at 80% field capacity or higher. Irrigation was applied as required to prevent any drought stress during grass establishment. Turfgrass species were maintained at cutting height of 4 cm and were mowed once a week using a reel-type mower. All data were subjected to analysis of variance using SAS 9.1 (SAS Institute Inc., Cary, NC) and Fisher’s protected LSD test was employed at the 5% probability level.
Results indicated that Trinexapac-ethyl and drought reduced growth, fresh weight and dried above ground organs significantly. Wheatgrass growth in concentrations 0.25 and 0.5 kg/h were 19.20 and 26.90%, respectively. Previous studies reported plants that have slow-growing shoots may survive more extended periods than faster-growing plants in drought conditions. Slow growth may reduce the adverse impact of drought by conserving water and carbon energy, and plants can use limited water to survive drought for an extended period of time. Unlike drought stress, Trinexapac-ethyl improved the quality of plant tissues and their color. Increase in turf quality under TE treatment might occur as a result of improved canopy photosynthesis capacity and single-leaf photochemical efficiency. Drought stress reduced relative water and chlorophyll content, increased proline level and finally led to electrolyte leakage. Trinexapac-ethyl improved wheatgrass in drought stress conditions by increasing relative water content, prolin, chlorophyll and decreasing electrolyte leakage and increased wheatgrass to drought stress resistance. Proline acts as an osmotic regulator in cytoplasm and vacuoles, protects proteins against dehydration, adjusts osmosis; detoxify radical active oxygen species, keeping more stable antioxidant enzymes. Proline immediate increase under drought stress is associated with decreasing leaf water content, in turn, induced drought tolerance. Under drought stress conditions, penetration of root depth and effective root depth has been increased, while Trinexapac-ethyl did not affect root traits significantly. The results of the present study indicated that TE decreased damages on drought stress probably via improving turf quality, chlorophyll concentration, leaf water content, proline content and less electrolyte leakage in Wheatgrass.

Chelidonium majus L. belonging to the Papaveraceae family، grows naturally in north of Iran with anti-cancer and anti-HIV properties because of isoquinoline alkaloids such as morphine، codeine، papaverine، thebaine and noscapine. The aim of this study was to quantify the amounts of the mentioned isoquinoline alkaloids in the samples collected from different altitudes of north of Iran، and investigate the effect of environmental factors on the amounts of these compounds. Therefore، five regions were selected including Mazandaran، Golestan، and Firoozkouh، and after quantitative measurements of alkaloids، the effect of altitude was also evaluated to determine its impact on the amount of these compounds. According to the obtained results، the maximum amount of the compounds mentioned above were 0. 25، 0. 18، 0. 02، 2. 14 and 0. 27 w/w، and the minimum were 0. 11، 0. 0، 0. 0، 0. 11 and 0. 0 w/w، respectively. Altitude showed a significant negative correlation (p<0. 01) with the amount of these compounds.

Among the most important and most valuable medicinal species that grows mainly in mountainous areas and areas of high botanical family as thyme or Thymus kotschyanusLabyath is, different species belonging to the dark Ha¬Y though almost all over the world Prakndh¬And but specifically in the areas ofclimate and geographical distribution of species Mdytranh¬Ay more accumulation in Turkey, Iran, Iraq and the Caucasus have been reported. To evaluate the effect of growth in height and four different drying method (direct sunlight, shade, 900 and 360 watt microwave) and genetic and ecological conditions on the plant are examples of plants at three altitude regions (2100, 2700 and 3300) at 100% flowering with a height of 10 cm from the ground up and in vitro, in essence Klvnjrv essential oil with gas chromatography connected to mass spectrometry (GC-MS) were examined. According to the results of analysis of variance on height and different drying methods showed that Sf¬HayVzn¬Tr with (36.667) and the humidity with (39.118) and essential oils (71.1) and oil percentage (26.0) was statistically significant at the one percent level, as well as the drying of essential oils (07.0) at the level of a statistical percentage and oil percentage (03.0) at the level of five percent were statistically significant. The effect of height and different drying methods on the amount of essential oil of thyme showed that most of thymol, carvacrol, alpha-terpinene, followed by Seaman, terpinene, borneol, caryophyllene, and caryophyllene oxide Dltakadynn and at one percent were statistically significant.

The use of such biostimulants as humic materials has recently become common in turf management operations. These products have been used to help the establishment of turfgrass and to enhance the turf stress tolerance capacity. This experiment was aimed at studying the effect of humic acid on some growth factors in turf grass. It was carried out in a factorial Randomized Complete Block Design (RCBD) of four replications and in controlled conditions. Turf seeds were sowed in polyethylene pots and following the establishment of the plants, they were monthly sprayed with Leonardite humic acid in concentrations of 0, 100, 400 and 1000 mg/L. Nine weeks past the start of treatments, such characteristics as height, fresh and dry weight, as well as the level of such elements as micro and macro nutrients were measured along with the visual quality of samples assayed. The results revealed that application of humic acid in concentrations of 100 and 400 mg/L were more effective than 1000 mg/L. The concentration of 100 mg/L positively affected the fresh and dry weight as well as the visual quality of the plants while the 400 mg/L concentration more profoundly affected K and Fe. The two concentrations of 400 and 1000 mg/L exerted a more serious effect on Zn content. None of these concentrations played any role on P content. An increase in humic acid concentration (1000 mg/L) caused a reduction in the height of the plants.