PLANT AND ECOSYSTEM
Year:2009 | Volume:5 | Issue:18|Papers Count:8

In this survey flora of Taknar copper mine region in Bardascan ‏ has been studied. Collected plants were recognized and determined families, genera and species of them by using of indispensable references. Alphabetically list of taxa in this region was provided on the base of families and scientific name. Collected plants were transmited to Herbarium of Reserch Center for plant Sciences in Ferdowsi university of Mashhad. The life form of plant species was determined by using ‏ Raunkier’s method. The plants of Taknar copper mine region ‏ including 39 families, 121 genera and 159 species the more species belong to Asteraceae with 22 species. Life forms of plants of Taknar copper mine region are including: 60% 38.‏ therophyte and%20.75 hemicryptophyte, %9.43 geophyte, %5.66 chamephyte and%3.77 phanerophyte.

In order to investigate the effect of seed hardening on germination percentage and germination rate of Common bean (Akhtar cultivar) an experiment was conducted in 2008 in seed laboratory of the Islamic Azad University, Shahre-rey branch. The experimental design was completely randomized design with four replications. Five treatments of seed hardening including, 12 hours soaking and 12 hours drying of seeds at three times, 12 hours soaking and 12 hours drying of seeds at four times, 24 hours soaking and 24 hours drying of seeds at tree times, 24 hours soaking and 24 hours drying of seeds at four times and no hardening of seeds (control) were studied. Results showed that the effect of seed hardening on germination percentage and germination rate was significant at p< 0.01. Soaking and drying of seeds in comparison with control treatment, increased germination percentage and germination rate. The highest germination percentage (99.25%) and germination rate (1.77 days) was achieved in 24 hours soaking and 24 hours drying of seeds at four times.

In order to study the effect of plant density on the forage yield, grain yield and yield components of three barley genotypes in dual-purpose sowing conditions, a field experiment was conducted in 2004-2005 growing season. The experiment was split-plot with RCB design and three replicates. Main plots were three barley genotypes (Jonoob, Tropy and 13 Sarasary) and sub-plots were four plant densities (300, 400, 500 and 600 plats per m2 ). Forage was removed from five cm above the ground at the beginning of the stem elongation phase. Results indicated that the genotype and plant density effect on grain yield was not significant. The interaction effect of the experimental treatments was not significant for grain weight and grain yield, but it was significant for biological yield, number of spike per unit area, number of grain per spike and harvest index traits. The highest grain yield, biological yield, number of spike per unit area and grain weight was in Tropy genotype. The differences among genotypes and genotype._density were not significant for hay (dry forage) and forage (fresh forage) yields. The highest and the lowest hay and forage yields were in 600 and 300 plants per m2 treatments, respectively.

This experiment was conducted in the spring‏ 2007 at Ardakan in order to assess the genetic diversity (or variation) in morphological and phonological traits in 204 naked barley lines and to determine the affecting factors on yield by multivariate statistical analysis. Due to the high number of genotypes, measurements were based on planting rows without replication. Selection was according to the morphological and phonological traits. Genotypes showed significant differences in all measured traits especially for seed yield. The highest seed yield was obtained from genotypes by numbers 28, 31, 34, 36 and 37. Yield had the highest correlation coefficient with green cover percentage (r=%43), days to flowering (r=%39) and height (r=%38). According to the path coefficient analysis, the yield components including‏ of tillers‏ of seeds and 1000 seed weight showed positive direct effect on grain yield and 1000 seed weight showed the highest amont for it. Principal‏ Component Analysis (PCA) showed 4 main components including HI, spike position relate to height, lodging percent and potential seed yield According to the factor analysis based on the first factor stem elongation was distinguishly separated from the other traits. So may low temperature had a major effect on it. Dendogram derived from cluster analysis based on squared euclidian distance divided the trait in‏to two groups. Grain yield showed the most similarity with date of flowering. According to results of stepwise regression, emergence percentage, height and days to flowering caused the most variation in yield respectively, and they entered to the regression model. Therefore, in yield improvement approaches, selection can be done according to the vegetative traits including green cover percent, height and days to flowering.

Pistachio (pistacia vera L) is one of the strategic products of our country and after oil ‏this product has devoted the most amount of exporting to itself. Considering the chilling injury of pistachio it is an endangered product. Determining the critical temperatures at the time of happening, the damage has helped the use of on time and suitable ways for preventing the happening ‏damage and it can also be used to estimate the amount of damage of the product. This damage is resulted from the decreasing of temperature in the early spring which sometimes causes considerable. damage for this reason this research was carried out in Dameghan Azad university during 2007-2008. This experiment was done in a factorial form with a completely randomized block design with two factors of type cultivar with three kinds of pistachio cultivar including Abasali, Shahpasand and Khanjarie. The factor of temperature was with 5 levels of +2, 0, -2, -4, -6 degree centigrade. The experiment was done in three growth of productive parts including: swallowed bud, bloomed bud and the new formed fruit nuts. Samples were put in a freezing chamber (low-temperature incubator) in which temperature was decreased with a rate of 2oC per hour. At each thermal level, some samples were taken out and injury was studied. The results showed that the most sensitive stage to frost was bloomed bud and The most damage in to the frost was in the temperatures of -6 degree centigrade.The results showed that Abasali cultivar was more resistance cultivar and the Shahpasand was more sensitive one to spring frost. The Khanjari cultivar was semi resistance cultivar to spring frost.

This research was conducted to determine the more salinity tolerant species of Medicago sativa and Onobrichis sativa. Two genotypes ‏ selected for each species experiment was conducted based on a factorial design including five salinity levels of 0, 100, 200, 300 and 400 mM Nacl and Cacl2 treatments.Data were recorded and analyzed for Chlorophyll (a) concentration (chl.a), Chlorophyll (b) concentration (chl.b) and total Chlorophyll (t) concentration (chl.t).The result of chlorophyllmetri revealed that there was a significant difference (P<0/01) between species, chl.a and chl.t‏‏. ‏Also, in the study of intraction between species and salinity Onobrichis in highest different‏ levels had the highest concentration of chlorophyll (a) and comparison diagrams shown that Onobrichis had the more resistance in compaire with medicago in all of salinity levels.

This zone which is studied is located in north eastern of Tehran with 45 to 77 kilometers in distance in Tehran –Firoozkouh path, and it is between 51/ 59 to 52 /23 east longitude and 35‏/ 35 to 35/ 45 north latitude. The height of this zone from sea surface (in the lowest part 1800 and the highest part 2300 meters) and the area of total studied area was 20.000 hac.The stages to this research were Soil Survey, Soil sampling, Laboratory analysis of soil samples, Collection of Climatic farming System for Selected Crops. Soil Suitability mapped with the use‏ of GIS system, and evaluation of qualitative Land Suitability for Land Utilization types in the study area. For qualitative evaluation of Lands data’s from detailed soil Survey, studies and Climatological figures and Topography Characteristics were used as the physical parameters, as Compared with crop requirements of using the standard and rating tables of sys and parametric methods proposed by FAO in 1973. Qualitative evaluation was carried out according to both simple limitation and parametric approaches by comparing climate, topography and soil characteristic to crop requirements. Results of qualitative land evaluation indicated that the climatic characteristics will cause limitation of %5.5 and %37.5 respecting for Safflower- Soybean growth and production in the research area some. soil characteristics and topography are limiting factors too. For All production, the main limiting factors included percentage of calsium. For safflower: the limiting factors included Coarse fragment and Relief and PH. For soybean: : the limiting factors included Coarse frag‏ment.Based on actual yield of crops in studied region the square root method was superior to simple limiting method in determining land suitability of land units.

The objective of this study was to examine the effect of different amounts of Super AB A 200 water-absorbent hydrogel on different types of porosity, water holding capacity and hydraulic conductivity of sandy loam soils in 2008-2009. The treatments of the experiment were: 1) soil type including sandy loam soils and 2) Super AB A 200 water-absorbent hydrogel in six levels including 0 (control), 0.05, 0.15, 0.30, 0.45 and 0.60 percent by weight.‏The study was carried out using a completely randomized block design with three replications, with 1.5*1.5 m plots, in research field of the Islamic Azad University, Shahre-rey Branch. The results showed that the addition of hydrogel and increased usage levels of it resulted in porosity augmentation, especially capillary porosity, as compared to the control.The application of water-absorbent hydrogel in levels of 0.45 and 0.60 percent increased the available water by 2 and 2.5 times, respectively. The hydraulic conductivity of soil was increased with increasing the level of water-absorbent hydrogel.‏The statistical analysis of means showed that there was a significant difference (pr< 0.001) between different levels of hydrogel usage together and with the control, in augmentation of capillary porosity, available water and soil hydraulic conductivity.‏According to the statistical analysis and economic aspects ‏, the application of 0.45% Super AB A 200 water-absorbent hydrogel is recommended to improve structure in sandy loam soils and increase their water holding capacity for optimum plant growth.