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241.
Owing to the importance of after anthesis water deficit in Mediterranean regions (such as Iran), this study has focused on harmful impact of after anthesis drought stress on grain yield (GY), photosynthesis, and some physiological characteristics of wheat. To this aim, a factorial experiment based on randomized complete block design with three replications was used in greenhouse conditions in Razi University in Kermanshah city of Iran, during 2010–2011 growing season. Two bread wheat genotypes, “Zagros” (tolerant to drought) and “Marvdasht” (sensitive to drought) were grown in normal water supply condition (100% of field capacity) and drought stress from anthesis until maturity (50% of field capacity). The results indicated that after anthesis water deficit considerably reduced grain and biological yields, thousand grain weight (TGW) and a number of grains per spike (NGS) among different traits in genotypes. Under well-watered and drought-treated conditions, genotypes in terms of all evaluated traits had considerable variations. Water deficit caused more reduction of net photosynthesis rate (Pn), stomatal conductance (gs), relative water content (RWC) of leaf, chlorophyll a, b (Chl), and soluble proteins content in sensitive genotype; values were respectively 66.3, 73.2, 14.6, 32.1, 46.2, and 25.6%. Better performance of tolerant genotype under water deficit was associated with a great ability in production of some osmoprotectants as inositol, glycerol, and erythritol sugars. Rather adaptation of tolerant genotype to water deficit may be attributable to having maximum soluble protein, sugar alcohols, Chl content, RWC, gs and Pn in drought stress, and with respect to the results, wheat might not be able to synthesize mannitol. Transfer of gene(s) producing mannitol may cause more improvement of growth performance of wheat under stresses. 相似文献
242.
243.
Nastaran Nazariani Asghar Fallah Majid Lotfalian Mojtaba Imani Rastabi 《Journal of Sustainable Forestry》2017,36(3):199-212
Zagros forests are one of the vegetative regions which have been located in the west of Iran. The investigation of sustainable forest management in Zagros is one of the key issues which make us to consider the challenges concerned with the protection of forest resources and socioeconomic problems of local people. Demand for criteria evaluation and indicators for sustainable forest management from local to national level to conduct administrative affairs have been increased. The aim of the present study is to evaluate 7 criteria and 65 sustainable indicators which have been utilized in the Near East. Accordingly, a questionnaire, with its reliability confirmed by experts, was distributed among involved participants. The results indicated that the Cronbach’s alpha coefficient for the questionnaire was 0/729. Then, using DEMATEL model, the sustainability criteria were prioritized and the significant correlation among them determined. Likert scale was also utilized to rank all the indicators, and in terms of their relative weight they were compared with. The result indicated that the most significant criteria were legal, political, and institutional frameworks, and protective functions of forest criterion were the most influential factor. By analyzing the experts’ attitudes, reliance on natural regeneration indicator with the relative weight of 31/15% was the most significant criteria in the region. The existence of number of seed provenance with the relative weight of 9/17% was the least significant role. At the end, 27 verifiers, 25 threshold values, and the most significant indicators in this research were determined. 相似文献
244.
Sayyed-Hassan Tabatabaei Seyyed Mohammad Mousavi Seyed Majid Mirlatifi Rezvan Sadat Sharifnia 《Journal of plant nutrition》2017,40(8):1133-1142
Knowing the concentrations of the nutrient elements in soils is important due to their toxic effect on humans and the environment. The aims of this study were to assess the effects of water quality, depths, and distances of lateral installation on soil chemical properties during turfgrass cultivation. A field experiment was conducted using a Split-Split-Plot design based on the randomized complete block (RCB) design with two treatments (well water and wastewater) and eight sub-treatments (45 and 60 cm distance of the laterals and 15, 20, 25, and 30 cm depths of laterals) in three replicates on a sandy loam soil, in Shahrekord, Iran. Soil samples were collected from 0 to 30 and 30 to 60 cm depth for measuring nitrate (NO3?), electrical conductivity (EC), and pH at the end of the experiment. During the experiment, fecal coliform was also measured at the soil surface. Results indicated that by increasing lateral distance, NO3? level increased in both layers. With installing laterals in deeper levels, NO3? concentration decreased at the beginning, then increased in the first layer, whereas in the second layer, NO3? concentration decreased. In addition, installing laterals in deeper depth caused an increase in soil EC in the top layer, but a decrease in the lower layer. However, the results showed that there was no significant effect of the treatments (well water and wastewater) and the sub-treatments (distance and depths of laterals) on soil pH. The results also show that with increasing laterals depth, fecal coliform level decreased at the soil surface. 相似文献
245.
Mahmood Sinaie Kazem Darvish Bastami Masoud Ghorbanpour Hossein Najafzadeh Majid Shekari Sara Haghparast 《Fish physiology and biochemistry》2010,36(4):1235-1242
It is of crucial importance to study on the biomarkers types to assess the specification of the pollutants and health status
of marine ecosystems in environmental evaluation projects. In this respect, total metallothionein biosynthesis and mercury
bioaccumulation in the liver and gills under acute mercury exposure were investigated in fish, Scat (Scatophagus argus). Spotted scat was exposed to different mercury concentrations (0, 10, 20, 30) for 24, 48, 72 h. Total MT levels were determined
by enzyme-linked immunosorbent assay (ELISA) method. Mercury contents were determined through cold vapor atomic absorption
spectrometry (CVAAS). Induction of MT during exposure was tissue specific, displaying different response pattern in gills
and liver. Mercury accumulated in liver much higher than in gills and the latter also showed lower MT level (P < 0.05). MT biosynthesis in liver showed a significant (P < 0.05) increase after exposure to different mercury concentration with increase in exposure time, whereas total MT content
did not significantly (P > 0.05) change in gills except for 72 h exposure at 30 μg l−1. Nonetheless, the relationship between MT biosynthesis and Mercury bioaccumulation in both tissues was significant (P < 0.05). The results suggest that this form of MT in S. argus was Hg inducible and could be extended as a biomarker of mercury pollution in marine ecosystems. 相似文献
246.
Late blight (LB), caused by Phytophthora infestans, is one of the most devastating diseases of tomato (Solanum lycopersicum) worldwide. Aggressive pathogen isolates resistant to fungicides have driven research in favour of finding new sources of host resistance for tomato breeding. Recently, we reported S. pimpinellifolium accession PI 270443 exhibiting LB resistance stronger than all commercial LB-resistant tomato cultivars. The purpose of this study was to examine the inheritance of LB resistance conferred by this accession. An interspecific cross was made between PI 270443 and a LB-susceptible tomato breeding line and advanced to F10 generation. A total of 166 F9 and corresponding F10 recombinant inbred lines (RILs) were evaluated for response to LB in four replicated greenhouse experiments. Estimates of heritability (h2) of LB resistance, determined by parent–offspring (F9:F10) correlation analysis, ranged from 0.66 to 0.81, with an average of 0.76. The moderately high h2 of LB resistance in PI 270443 suggests the utility of this accession for tomato breeding. Molecular mapping and RNA-sequencing efforts are underway to identify genes underlying LB resistance in PI 270443. 相似文献
247.
Fatemeh Rajaei Abbas Esmaili Sari Abdolrassoul Salmanmahiny Majid Delavar Ali Reza Massah Bavani Raghavan Srinivasan 《Paddy and Water Environment》2017,15(3):541-552
Pasture, forest, and farmland are the dominant land covers in the Tajan River watershed and this landscape status has a direct connection with nitrate pollution. Understanding the correlations between landscape variables and nitrate pollutant is a priority in order to assess pollutants loading and predicting the impact on surface water quality. The soil and water assessment tool was used to simulate nitrate loads in different land cover types in different years. The landscape pattern was calculated by FRAGSTATS. The contributing share of each land use/land cover shows nitrate pollutant produced by grassland (5.7%) and forest (29%) are less than those produced by agricultural land (64.2%). Agricultural land was identified as the main source of nitrate pollution. Paddy fields and orchards had the most intensive soluble nitrate loss especially in spring and summer. Statistical analysis indicated that nitrate was positively associated with patch density, edge density, patch number, total edge, effective mesh size, largest patch index, and landscape shape index (p ≤ 0.01). We then analyzed how nitrate was related to landscape attributes in six different sites. Also the regression analysis results suggested that landscape metrics could account for more than 94% of the variance of nitrate in the whole catchment. The regression models confirmed the great importance of the agriculture metrics and forest metric in predicting nitrate in watershed. Defining the generation and extent of pollution in this particular watershed which discharges into the Caspian Sea can constitute an important step toward protecting this ecosystem. 相似文献
248.
Sareh Sayari Majid Rahimpour Mohammad Zounemat-Kermani 《Paddy and Water Environment》2017,15(4):879-887
In this study, a zero-inertia finite element model (ZIFEM) is developed and applied for simulating all phases of furrow irrigation based on Saint–Venant equations. The complexity and nonlinear behavior of the Saint–Venant equations are the major difficulty in developing a finite element model to simulate furrow irrigation. Therefore, through the Galerkin FEM approach, the model assesses the free surface flow on a variable cell length at each time step and determines the suitable element length for each individual cell and the model solves the equations by using an iterative method. Along with the free surface flow phase, the infiltration phase is estimated by the Kostiakov–Lewis equation. The ZIFEM model is verified using seven experimental data sets collected from the literature and observed data from the farm consisting of two free drainage furrows with a length of 72 m, a top width of 0.8 m, a depth of 0.25 m and a slope of 0.2%. The model accuracy is studied to simulate advance and recession trajectories and runoff by calculating the root-mean-square error (RMSE), relative error and percentage error. It is observed that in all irrigation events, the proposed model reasonably agreed with field measurements. An evaluation of the RMSE shows that in 81.25% irrigation events the ZIFEM is more accurate than the WinSRFR model. In overall, the results of the model suggest that the ZIFEM can be introduced as a potential numerical tool for analyzing and evaluating furrow irrigation. 相似文献