PLANT AND ECOSYSTEM
Year:2015 | Volume:10 | Issue:41|Papers Count:9

The 1466 hectares Asadabad catchment with an altitude of 2050-2650 m is located in the East of Ashtian. The amount of the annual precipitation and the average annual temperature of the area is 283 mm and 10.33ºC, respectively. The purpose of this research was the identification of the plant species, the introduction of the flora, and the determination of the life forms and the geographical distribution of species in the area. For so doing, plant samples were collected from the area and identified by means of different flora during the growing season in 2012. The biological spectrum of the species was plotted by means of the life forms results. The position of the area within Iran’s phytogeography classification was studied based on the chorotype of the species and the available resources. In this area, 180 species were identified, which belonged to 39 families and 122 genera. The following families had the highest number of species: Asteraceae (30 species), Papilionaceae (20 species), Poaceae (18 species), Lamiaceae (14 species), and Liliaceae (12 species). Hemicryptophytes, with 89 species (49.5 %), were the most frequent life form in the region. The geographical distribution of 138 species (76.67 %) was limited to Irano-Turanian region.

Chalpo region is located in the Northeast of Iran, 18 km from Kashmar, between 58o 22’ 11” to 58o 32’ 44” Eastern longitude and 35o 43’ 31” to 35o 37’ 32” Northern latitude. The surface area of this region is approximately 14107.68 ha. This area is mountainous with an average annual precipitation of 335 mm. The average maximum and minimum temperature is 25.6 c in ugust and -7 c in January, respectively. The flora of the region was studied and the life forms and the geographical distribution of the plants were identified. Generally speaking, 31 families containing 112 genera and 127 species were identified. The most significant plant families were Asteraseae with 17 species, Poaseae with 13 species, and Lamiaceae with 9 species. Hemicriptophytes, therophytes, Chamophytes, Phanerophytes and Geophytes were the most frequent life forms, respectively with 53 (41.7%), 28 (22%), 17 (13.3%), 15 (11.8%), and 14 species (11%). The high percentage of Hemicryptophytes indicated that the area had a cold and mountainous climate. Irano-Turanian plants were the most frequent choryotype of the area with 74 species (10.2%).

In the present experiment, random amplified polymorphic DNA (RAPD) markers have been used to characterize the genetic diversity among 10 landraces of Aloe vera in Iran. From among the 20 primers used in this study, 10 amplified 126 scorable RAPD bands, among which 106 were polymorphic (84.1%). The average number of the bands was 12.6 for each primer. Dice similarity index was used for measuring the genetic similarities among the landraces. The highest amount of similarity (0.62) was found between Borazjan a and Sarcorreh a populations, whereas the lowest belonged to Boushher b and Sarcorreh b. UPGMA algorithm was used for the cluster analysis. The cluster analysis separated the 10 landraces into two main groups. The results indicated that RAPDs could be efficient markers to assess the genetic diversity in Aloe vera populations.

In this study, the impact of different sources of carbon, abscisic acid (ABA) – alone and in combination with polyethylene glycol (PEG) in different concentrations – on the percent of early embryos responding to the secondary embryo (SE) induction and the average number of SEs in each early embryo within Global, PF704, and Option cultivars was analyzed. Exploring the average interactions between the embryos responding to SE induction indicated that the 0.2 and 0.3 M sorbitols induced the highest secondary embryogenesis percentage (SE%). With respect to the average number of the induced SEs on MDE, the 0.3 M (300 mOsml-1) glucose in Option cultivar had the highest number of SEs and the fructose in all concentrations produced the lowest number of SEs per microspore-derived embryos. An increase in the concentration of the abscisic acid left a negative impact on the induction of SEs. The 0 mM concentration (control) produced the highest number of SEs. With respect to the maturation trait of the SEs on early embryos, it was observed that the abscisic acid left a positive impact on the three cultivars. The variance analysis of the impact of PEG and the abscisic acid on the average number of induced SEs of the Option cultivar demonstrated significant differences between the simple effect of PEG and the interaction effects of PEG and the abscisic acid at P<0.001 and 0.01, respectively. The simple effect of the abscisic acid was not significant. In addition, the effect of PEG and the interaction effects of PEG and the abscisic acid on the maturation of SEs was significant at 0.1 and 0.5% confidence intervals, respectively. Comparing the mean of different levels of PEG with the mean of the number of induced SEs/MDE in Global cultivar indicated that PEG had a negative impact on SE induction and reduced this trait.

The cancer rate has been increasing rapidly through the recent years. An extensive research is taking place in an attempt to find new and effective anticancer reagents. While the anticancer impacts of polysaccharides extracted from different microorganisms have been extensively studied, research on the anticancer effect of cyanobacterial polysaccharide is scant. Cyanobacterial polysaccharides have special characteristics compared to the polysaccharides of the other microorganisms. In the present study, two species of cyanobacteria i.e., Nostoc sp. ISC26 and Nostoc sp. ISC101, were cultivated in BG11 environment. The polysaccharides of Nostoc sp. ISC26 and Nostoc sp. ISC101 were extracted. The structure of the extracted polysaccharides was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and their quality was analyzed by spectroscopy and gel electrophoresis. The anticancer impact of the extracted polysaccharides on lymphoblastoid cell lines was measured by MTT procedure. The results indicated that both of the extracted polysaccharides had significant anticancer effect on LCL and their anticancer impact was dose dependent.

To explore the effect of different types of Zinc and Manganese fertilization on the quantitative and qualitative yield of wheat, a factorial experiment was carried out in a randomized complete block design with 3 replications in the greenhouse of the research farm of the Faculty of Agriculture, Islamic Azad University, Saveh branch, in November 2008. The factors of this research included 3 levels of soil Manganese consumption, 2 levels of spraying, and 3 levels of soil Zn consumption. The results indicated that the highest grain yield belonged to 5 mgr/kg concentration of soil Manganese consumption and 10 mgr/kg of soil Zn consumption. It was observed that the soil Manganese consumption significantly increased grain yield, 1000 grain weight, the number of grains per spike, and the concentration and quality of Zn and Manganese in shoot, whereas the Manganese spraying only significantly increased the concentration of Manganese and Zn in the grain, the quality of grain Manganese, and the concentration of Manganese and Zn in the shoot. According to the results, the soil Zn consumption significantly increased yield indices, the number of tiller, the concentration and quality of Zn and Manganese in grain, and the concentration of Zn and Manganese in shoot. However, the number of tiller and protein percentage did not significantly improved. Additionally, the results indicated that the application of Zn in the form of spraying compared to the control treatment significantly increased grain yield, the concentration and quality of Zn and Manganese in the grain, and the concentration of Zn and Manganese in the shoot.

The present research was carried out to estimate the amount of biomass and carbon sequestration in the leaf and the mean area of the leaves of the Quercus persica in Shahanshah forest in Lorestan province. In the present experiment, 50 oak coppices were randomly selected and 5 leaves were collected from the 4 main geographical directions from each oak coppice at 1.5 m height. After drying, the average amount of leaf biomass was calculated for each sample. The amount of the carbon stored in the leaf was estimated by burning and using electric furnace and leaf area was calculated by means of leaf area meter. The results were estimated for the whole area using allometric equations. The results indicated that the mean of the leaf biomass, leaf carbon sequestration, and leaf area were 860.21, 662.48 kg/ha and 4732 m2/ha respectively. In addition, on the basis of the results obtained from the analysis of variance and Duncan test, it was observed that there were significant differences between the Northern direction with the Southern and Eastern ones with respect to the amount of carbon sequestration, biomass, and mean area of leaf at P<0.5.

Regeneration of the tree plant of Pistacia atlantica in the wooded pastures depends on the presence of the understory plant species. Due to the fact that overgraze has caused the depletion of forage species in wooded pastures, artificial range management in these ecosystems is essential to compensate for this inhibiting effect on the regeneration of forest species. Since the determination of the species which are resistant to mastic inhibitors is essential for this purpose, the present experiment was carried out in an attempt to investigate the allelopathic effects of Pistacia atlantica’s leaf extract on the germination percentage, the rate of germination, the length of rootlet, and the length of stalk in two seedy plants i.e., Agropyron deserto rum and Agropyron elongatum, which are widely used to improve and revive rangelands in Iran. For so doing, the powder of plant's leave tissues were collected from the natural habitats and dried. Four treatments including 0 (control), 25, 50, and 100g of the powder combined with 1000g of washed sand were applied separately in greenhouse with three replications following a complete randomized design. After the cultivation of 25 healthy seeds of the experimental species in each vase, the dependent variables were analyzed using one way ANOVA test and Dunkan multi-amplitude method. Additionally, for comparing the condition of the allelochemicals of the under- and between-plant, sample soil was collected from the habitat to conduct the two treatments and compare them using the independent tTest. The 100 gr/1000kg soil treatment left a negative impact on all of the analyzed traits of A deserterum. Considering the shoot growth rate of A elongatum in 50 gr/1000 gr sand treatment and the synergetic effect of root growth of A elongatum from the plant under soil, it can be concluded that these two species are not highly sensitive to allelochemicals of Pistacia atlantica. The results of the present experiment indicated that it is possible to successfully resuscitate the understory with low tree density.

Today, climate change is considered as one of the six environmental issues influential in the sustainable development and poverty eradication. Hence, it is essential to identify methods for reducing the risks of global warming. Improving the process of carbon sequestration in soil and plant appear to be the best options. From among the various parts of the ecosystem, the rangelands have a significant potential for carbon sequestration due to their large size. However, carbon sequestration is affected by natural and human factors, one of which is grazing management. The present experiment was carried out in an attempt to investigate the effects of grazing on carbon sequestration in Atriplex verucifrum and the soil in and out of the exclosure areas of Tez Kharab region in Urmia. The results indicated that, carbon storage in the organs of At.verruciferum significantly increased by exclosure. The results also showed that the amount of carbon storage in the biomass of the whole exclosure area (201.07 Kg/ha) is more than the grazing site (106.33 Kg/ha) out of the exclosure area. A comparison of the total amount of carbon in the areas under the study revealed that the total amount of the stored carbon in the exclosure site (73.069 Ton/ha) is more than the grazing site out of the exclosure area (61.65Ton/ha). The analysis of the soil characteristics including: pH, EC, K, P, N, lime, and soil bulk density indicated that there were differences in soil characteristics, except for phosphorus and lime (P<0.01).