فصلنامه گیاه و زیست بوم
پیاپی 40 (پاییز 1393)

The destruction of (AstragalusgossypinusFisch.) habitats in Isfahan province has had several environmental and socio-economic impacts. To restore these habitats by means of planting AstragalusgossypinusFisch., determining its potential habitats in the province becomes essential. In an attempt to fulfill this objective, first, the significant environmental and biological factorsof A.gossypinusFisch.in different habitats of the provinces were selected. The relation between them was then examined and illustrated in the form of RDA graphs. Afterwards, using the length of the vector in each of these environmental factors in graphs, their ultimate impact on the final model was determined and the potential habitats of this species across Isfahan province were identified by means of AHP approach. According to the results, the ecological characteristics required for optimizing the growth of A.gossypinusFisch.in Isfahan province rangelands include: 200-400 mm of precipitation, 100 frozen days per year, about 8 degrees of slope, 160 ppm K in soil, 30% clay, 40% sand, and pH of 7.9.

A fundamental base inthe ecology of plant societies is that the plant species separately respond to the environmental gradients anddepending on the habitat conditions, the ecological requirements of the plants and their tolerance range can vary. In order to identify the relation between plant vegetation parameters and the environmental and edaphic elements, some parts of the protected area of Jahannama in Saraliabad rangelands in Gorgan were examined. One meter square plots were randomly established through field experiments and ten R plots were used for measuring tree altitude in the fields. The percent of canopy and topographic factors (slope, direction, &altitude) were considered as dependent and independent variables in each plot, respectively. Afterwards, soil samples were collected from each region for edphic analysis as independent variable. The most effective factors on percent of canopy of plant vegetation were determined using multivariate stepwise regression analysis. The results indicated that the physical rather than the soil factors associated with altitude, slop, and direction significantly contributed to the distribution of plant vegetation (P<0.05). The relation between the physical factors and the percent of canopy the dominant species indicated that Juniperussabina, Cousiniaglaucopsisreversely correlated with altitude and slope while Festucaovina positively correlated with these factors. No Association was found betweenOnobrychiscornataand heightwhereas it significantly and negatively correlated withslope percent. Canopy percent inJuniperusSabina, Festucaovina,and Cousiniaglaucopsis decreasedwith soil acidification and positively correlated with the electrical conductivity of soil. In addition, canopy percent of JuniperusSabina, Onobrychiscornata, and Cousiniaglaucopsis increased as the soil got rocky but Festucaovina decreased with an increase in the percent of sand in the soil. With an increase in the effective depth of soil, the canopy percent of JuniperusSabina increased. InOnobrychiscornata and Juniperuscommunis, the canopy percent increased up to 75cm soil depth but decreased in deeper levels of soil.

Oak tree forests of Kakareza are situated on 45 km North East of Khorramabadin middle Zagross region. The present experiment was carried out in an attempt to investigate the changes in the surface and canopy density of the region in different heights and distances from the village by interpreting the aerial photos taken in 1955 (1:55000) and 1997 (1:40000) and by means of GIS software. For this purpose, the pictures were first geometrically corrected and then the layers of canopy thickness wereidentified in a 2 millimeter dotted network. The frontier line of separated layers was drawn in the form of closed polygons and the area of these polygons was measured separately. Any changes in the area of these polygons in every stage of photographs were compared through software. At each stage, the photos were compared and the map of the changes in the layers of canopy thickness was developed. The mapsof the heights in threeclasses(1400-1700 m, 1700-2000m, &over 2000m) andthe distancesfromthe villagemapsin threeclasses(0-300 m, 300-600m and600-900m) were prepared for two periods in Arcviewsoftware. By combining each of these maps withthe density mapdesigned in 1955 and 1997,the amount of forest change in different heights and distances from the village were determined. The results indicated that the biggest and the smallest areas of dense (F1), semi-dense (F2), and sparse (F3) densities respectively belonged to the heights of 1700-2000 m beyond 2000 m. The results also indicated that the forest density in dense (F1) and semi-dense layers (F2) had the biggest area in distances far from the village and the smallest areas in parts which were closer to the village. On the contrary, the sparse (F3) layer had the biggest area in places near the village and the smallest areas belonged to longer distances.

The present study examined the separate and collective impacts of using compost and solarization on tomato (Lycopersicumesculentum). Tomato cultivation area was solarized for 14 hours a day over a 2 months period in order to increase the soil temperature beyond 60 degree Centigrade. At the end of this period, the compost which was created using different strategies was added into the 20 cm depth of the soil. The purpose of solarization in this experiment was removing weeds and pests in an attempt to decrease the competitive ability and increase the fruit growth, plant germination, and photosynthesis in a randomized complete block factorial design. Accordingly, by removing the weeds, the amount of shadowing on the plant was decreased and this increased the photosynthesis. The purpose for using compost was increasing the growth and nutritional abilities of the plants by means of the organic materials. In other words, the overall purpose was operationalizing an experiment in an organic farm. The results indicated that the fruit weigh significantly increased. The plant yield also increased up to 37% which can be attributed to the removing of the weeds by means of solarization. This way, the weed shadowing is removed and due to the absence of another weed, there is no competition between the plant and the weed. Using compost significantly increased the photosynthesis and plant growth. The existence of nutrients, organic materials, and organisms such as ectinomisets and protozas, which enhance the stabilization process, made the soil nutritious. Destruction of pathogens can be considered as one of the significant aspects in the process of producing compost. The process of producing compost and its collective function with solarization omitted pathogens.

In an attempt to investigate the impact of magneticwateronseedhyoscine and the growth of two Datura species (i.e. Datura.metelstramonium&Datura. Stramonium), an experiment was carried out in split plotrandomized completeblock designinthreereplications inDamavand in 2010. The traits under analysis included: the percent of hyoscinealkaloids, 1000-seed weight(g), the flower number, the leaf number, the average number of club per plant, and fruitweightper plant(g). The results of response curves in regressionanalysis indicated that the values ofthe magneticwateronthetraitofseedalkaloidhyoscine were significant at 5% confidence interval. The linear regression of fruitweightper plantwas significant at P<0.01. In addition, for the flower trait, the numberoflinearandquadraticeffectswassignificantat 1% confidence interval. The linear regression of the leaf number and the quadratic effect of the average number of club per plant were respectively significant at P<0.01 and 0.05. The interaction effect between the species and the magnetic water indicated that the linear regression of the percent of seed hyoscinealkaloids, the linear regression and quadratic effect of 1000 seed weight, flower number, and the average number of club per plant, and the quadratic effect in the number of leaves were all significant at P<0.01. The results of the correlation analysis illustrated thatthecharacteristicleaf number, the meanof seedweightper plant,andthe average number offruitsperplantwandhad meaningfulcorrelation. The relationship between thenumber of leavesperplant, the averageseed weight, and the meannumber offruitsperplantwas alsosignificant. Stepwiseregressionanalysisshowed that1000seed weightandthe number of leaveshavea positive effect onthe grainofhyoscinealkaloids.

In the present study, the cut roses (Rosa hybrida cv. Full house) were treated with different concentrations (25, 50 and 100 ppm) of silver nanoparticles for 1 hour. After the pulsing treatment, the flowers were kept in distilled water for analysis during the rest of the study. The impact of silver nanoparticles on postharvest qualities of the cut roses including vase life, flower diameter,soluble carbohydrate content in leaves and petals, anthocyanin content of the petal, leaf chlorophyll content, the relative fresh weight,and petal turgidity content were examined.The results indicated that 50 ppm silver nanoparticle significantly delayed the senescence of the cut rose flowers. In addition, the aforementioned treatment significantly improved other postharvest parameters under study including the maximum vase life. The amount of soluble carbohydrate content in petals and leaves, anthocyanin concentration in petals, leaf chlorophyll, petal turgidity, and relative fresh weigh decreased during the evaluation stages in the postharvest period. The minimum amount of decrease was observed in 50 ppm silver nanoparticle treatment. The 100 ppm silver nanoparticle treatment negatively impacted the trait under analysis and resulted in the minimum amount of vase life. It can be concluded that 50 ppm sliver nanoparticle treatment is suggested for increasing the vase life of the cut roses cv. Full house.

Thymus is one of the significant species of Lamiaceae family. This genus has 350 permanent aromatic herbaceous or shrub species with various uses in food, sanitary, cosmetics, and pharmaceutical industries. In the present study, the low germination rate in Thyme samples obtained from the Gene Bank of the Natural Resources Institute along with the seeds collected from the national project of the genetic resources of the medicinal plants were examined using the suggested ISTA strategies, i.e. the dormancy test. The results indicated that the lack of germination in the sample seeds of the Gene Bank and the arena settlement problem relate to the long storage time (seed deterioration) and inappropriate time of seed collection. Although, using tetrazolium test, arelatively high percent of seed viability was obtained, but the result was not confirmed by standard germination test. The results indicated that the appropriate chilling period for dormancy breaking should not exceed one month. With an increase in the chilling time, no significant difference was observed among treatments with respect to the germination. It was also found that the long storage of the seeds (more than 7 years) results in seed deterioration and viability which can be attributed to the factors involved in seed collection such as the time of treatment. It can be concluded that the Thyme seeds which are collected for the Gene Bank must be harvested at maximum physiological maturity to present a high seed quality and storability.

Lamiaceae family has about 200 genus and 4000 species including Thymus. Most of the plants in this family have essences which can be applied in different pharmaceutical, cosmetics, hygienic, and food industries. Thymus genus hasdifferent species which are spread in different provinces of Iran. The purpose of the present study is to investigate the existing compounds in the essential oil obtained from the shoot organs of this plant species and their antibacterial impact. Samples were collected at the flowering stage from the plants in PereskinAlashtarof Lorestan province in 2011.The produced samples were shadow dried. To study the anatomical properties, the samples were stained with brown Bismarck and methyl green. Their essences were extracted by means of Hydrodistilation method using Clevenger device. Afterwards, the components and percent of the essential chemical compounds were recognized and separated completely using GC and GC/MS devices. Plate sink strategy was used to investigate the antibacterial impact of the essential oil of the species against four g+ and g-pathogen bacteria (i.e. Staphylocococus Aureus, Escherichia Coli, Pseudomonas aeroginosa, & β.streoptocococs) with the assistance of MAHmedium and measuring thediameter of inhibition zone. The laboratory analyses indicated that the species under study had anatomical similarities with other species such as T. eriocalyxand T. kotschyanusinLorestan. Based on the retention volume, retention time, Kovats retention index, and the comparison of these parameters with the standard components, the results revealed that this species has 45 components in its essence which together comprise 98.85% of the total essence. The main components included: Thymol (42.60%), Carvacrol (32.33%), Cymol (4.05%), γ-terpinene (3%), and Borneol (2.12%).The results confirmed the findings of the previous research with respect to the main compounds in the essence. However, the obtained amounts were different from the previous studies which can be attributed to the impact of the environmental factors or the strategies applied for collecting the samples on the biosynthesis of the essence. These factors include: the time and place of collection, plant growth stage, and the climatic changes. In addition, the results confirmed that the essence of the aforementioned species has antibacterial impacts.

Persian Cumin (Buniumpersicum[Boiss] B. Fedtsch) is a medicinal and aromatic plant which belongs to Apiaceae family. The purpose of the present study is identification and comparison of the chemical combinations in BuniumpersicumBoiss. essences in three different habitats of Kerman province. The Persian Cumin fruits were collected from three different habitats in Darehdor, Bibihayat, and Ravar in Kerman. The oils were obtained from fruits using hydro-distillationmethod and analyzed by means of GC-MS. The obtainedessential oil yields were 2.8, 3.2, and 4.4% (v/w), respectively. 27, 26 and 22 compounds were identified in samples which constituted 95.66, 97.39, and 97.81% of the total oils obtained from the three habitats, respectively. The main compounds in the samples obtained from Darehdor were γ-Terpinene (25.7%), Cumin aldehyde (18.4%), Limonene (9.3%), ρ-Cymene (8.1%), ρ-Cymene-α-ol (6.5%), and β-Pinene (6.2%) were found as the major components. InBibihayat sample, γ-Terpinene (29.1%), Cumin aldehyde (19.9%), ρ-Cymene (9.9%), Limonene (9.2%), ρ-Cymene-α-ol (8.6%), and 2-Carene-10-ol (6%) were characterized as the main compounds. In the essential oil from Ravar habitat, constituents such as γ-Terpinene (28.4%), Cumin aldehyde (20.1%), ρ-Cymene (14.5%), 3-Carene-10-ol (8.92%), Limonene (8.9%), and 2-Carene-10-ol (6.6%) were determined as the principal ones. Comparing the compounds comprising the essences in the samples under the study indicated that the essential oils were qualitatively and quantitatively different. This can be attributed to the ecological differences in the habitats including temperature, humidity, height from the sea level, and other soil, geographical, and genetic factors.