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51.
52.
Ebrahim Ahmadi Abolfazl Shirazi Naser Shams‐Esfandabadi Hassan Nazari 《Reproduction in domestic animals》2019,54(3):595-603
Despite the numerous potential applications of oocyte cryopreservation, the poor success rate has limited its practical applications. In livestock, particularly in ovine, the oocytes have low developmental competence following vitrification/warming process. Considering the occurrence of osmotic and oxidative stresses during the vitrification/warming process, the application of antioxidants and osmolytes may improve the developmental competence of vitrified/warmed oocytes. In the present study, we aimed to evaluate the effects of the addition of ascorbic acid (AA) and N‐acetyl cysteine (NAC) as antioxidants and glycine as an organic osmolyte either to the vitrification/warming solutions (VWS) or to the IVM medium on the developmental competence of vitrified/warmed ovine germinal vesicle stage oocytes. The survival rate in the vitrified groups was significantly lower than fresh ones. In vitrified/warmed oocytes, there was no significant difference in survival rate between supplemented and non‐supplemented groups. The addition of AA and/or NAC to the VWS or IVM medium and adding glycine to the IVM medium reduced the proportion of apoptotic oocytes and fragmented embryos, which was reflected as an increase in the proportions of metaphase II stage oocytes and blastocyst production. The best result was achieved by supplementing the IVM medium with NAC. In our study condition, antioxidants and glycine could improve the developmental competence of vitrified/warmed ovine immature oocytes, especially when added during IVM. 相似文献
53.
Sakineh Ahmadi Behrouz Harighi Jafar Abdollahzadeh 《European journal of plant pathology / European Foundation for Plant Pathology》2018,150(3):679-689
Bacterial canker is one of the most important diseases of stone fruit trees in various locations of Kurdistan province, Iran. Genetic diversity and evolutionary relationships among 20 fluorescent pseudomonads isolated from stone fruit trees with symptoms similar to bacterial canker were investigated using a polyphasic approach by means of phenotypic characterizations, repetitive PCR using the REP and ERIC primers and multilocus sequence typing (MLST) of four housekeeping genes (gapA, rpoD, gyrB and gltA). The pathogenicity of strains was carried out under greenhouse conditions. Twelve strains produced an expected amplified DNA fragment of about 752-bp which indicated the presence of the syrB gene. Based on MLST, these strains belonged to P. syringae species complex and included in the genomospecies 1, phylogroup 2b and 2d. Phylogenetic analysis of the other eight fluorescent pseudomonad strains by using gyrB and rpoD sequences allowed the identification of strains into P. fluorescens, P. putida and P. lutea groups. Unweighted pair group method analysis (UPGMA) of genomic fingerprints obtained by rep-PCR revealed 17 different patterns which grouped P. syringae strains into three clusters clearly separated from other fluorescent pseudomonads. MLST confirmed the genetic variability among strains obtained by rep-PCR. Grouping identified of P. syringae strains by both rep-PCR and MLST was related to geographic locations of strains. 相似文献
54.
Journal of Plant Diseases and Protection - The predatory flower bug Orius similis Zheng (Heteroptera, Anthocoridae) which originated in China is a polyphagous predator that feeds on a wide range of... 相似文献
55.
Laboratory/greenhouse and field experiments were conducted to evaluate the effects of salinity levels ranging from 1 to 12 dS/m on germination rate, 8 leaf seedling dry matter, seed yield, and seed oil content of the 8 Canola (Brassica napus) cultivars: ACSN1, Falcon, Shirali, Ceres, Tower, Cobra, Global, and Oyerka. Statistical results revealed that the factors: salinity, cultivar, and their interaction had significant (P<0.01) effect on germination rate and 8 leaf seedling dry matter. Based on statistical analysis seed yield was significantly influenced by both salinity and cultivar at the 5% significance level; while the cultivar factor had a significant effect on seed oil content, salinity did not show any effect on seed oil content. Analytical results, using the well-known sigmoid or S-shape salinity response function gave reliable results for determining tolerant and sensitive cultivars to salinity. Applying an existing model on canola response to salinity levels in different growth stages, the values of C
50 and P parameters were developed for local canola cultivars. Results showed that the response of cultivars to salinity levels vary in different growth stages. While a cultivar is tolerant in a growth stage, it may be sensitive to salinity in another growth stage. Based on observed data and ANOVA analysis, we concluded that ACSN1, Shiraly, and Falcon can be ranked as salt-tolerant, and Global and Oyerka as the salt-sensitive cultivars. 相似文献
56.
Due to urban growth, some agricultural lands have been replaced by residential, municipal, and industrial areas. In some cases the remaining agricultural land will not have enough water because of transfers from agriculture to M&I (municipal and industrial) users. Therefore, in many places, especially in arid and semi-arid regions, the use of treated wastewater as a reliable source of irrigation water has already been, or will be, considered in the future. Due to its unique characteristics, this new resource has many challenges that cannot be ignored, such as health issues, water quality, and long- and short-term effects on soils and crops. The study described herein considered the development of a new GIS-based model for planning and managing the reuse of treated wastewater for the irrigation of agricultural and green lands, considering various factors such as population and urban growth. The model is composed of several different modules, including an urban growth model. These modules are designed to help in the decision-making process for allocations of water resources to agricultural areas, considering factors such as crop types, crop pattern, water salinity, soil characteristics, pumping and conveyance costs, and also by comparing different management scenarios. Appropriate crops that can be grown with a specific water salinity and soil characteristics, proper water resources for each farm (according to pumping and conveyance costs, and analysis of water demand, and water supply) can be determined through the application of this model. The model can also rank agricultural areas and open spaces in and near an urban area according to their suitability for irrigated agriculture. 相似文献
57.
Integrated use of GIS,remote sensing and multi-criteria decision analysis to assess ecological land suitability in multi-functional forestry 总被引:1,自引:0,他引:1
The Zagros forests are a treasure of valuable oak forests, but they have been severely degraded from long-term misuse. Geographic information systems (GIS) and multi-criteria decision analysis (MCDA) have been increasingly used to improve the management of vulnerable ecosystems to prevent further degradation and increase the sustainability of land use. This study presents a methodology to assess land suitability using remote sensing (RS) to obtain wall-to-wall data for the calculations, GIS to analyze the data, and MCDA to rank alternative land uses. The criteria and subcriteria affecting the suitability of land for different uses were identified and weighted using an analytic hierarchy process. Variables used as subcriteria were assessed using satellite data and other sources of information such as existing maps and field surveys. Numerical values for the subcriteria were classified, and each class was given a priority rating according to expert judgments. Based on the ratings and weights of the subcriteria, a priority map was created for each land use using the weighted linear combination method. The priority maps for different land uses were overlaid to obtain a preliminary land use map, which often indicated several simultaneous land uses for the same location. The preliminary map was further edited by removing unrealistic, mutually exclusive land-use combinations. The study tested and demonstrated the potential of integrating RS, GIS and MCDA techniques for solving complicated land allocation problems in forested regions using a scientifically sound and practical approach for efficient and sustainable allocation of forestland for different uses. 相似文献
58.
F. Razzaghi S. H. Ahmadi V. I. Adolf C. R. Jensen S.‐E. Jacobsen M. N. Andersen 《Journal of Agronomy and Crop Science》2011,197(5):348-360
Drought and salinity are the two major factors limiting crop growth and production in arid and semi‐arid regions. The separate and combined effects of salinity and progressive drought in quinoa (Chenopodium quinoa Willd.) were studied in a greenhouse experiment. Stomatal conductance (gs), leaf water potential (Ψl), shoot and root abscisic acid concentration ([ABA]) and transpiration rate were measured in full irrigation (FI; around 95 % of water holding capacity (WHC)) and progressive drought (PD) treatments using the irrigation water with five salinity levels (0, 10, 20, 30 and 40 dS m?1); the treatments are referred to as FI0, FI10, FI20, FI30, FI40; PD0, PD10, PD20, PD30, PD40, respectively. The measurements were carried out over 9 days of continuous drought. The results showed that increasing salinity levels decreased the total soil water potential (ΨT) and consequently decreased gs and Ψl values in both FI and PD. During the drought period, the xylem [ABA] extracted from the shoots increased faster than that extracted from the roots. A reduction in ΨT, caused by salinity and soil drying, reduced transpiration and increased apparent root resistance (R) to water uptake, especially in PD0 and PD40 during the last days of the drought period. The reasons for the increase in apparent root resistance are discussed. At the end of the drought period, the minimum value of relative available soil water (RAW) was reached in PD0. Under non‐saline conditions, Ψl decreased sharply when RAW reached 0.42 or lower, but under the saline conditions of PD10 and PD20, the threshold values of RAW were 0.67 and 0.96, respectively. In conclusion, due to the additive effect of osmotic and matric potential during soil drying on soil water availability, quinoa should be re‐irrigated at higher RAW in salt‐affected soils, i.e. before the soil water content reaches the critical threshold level causing the drop in Ψl resulting in stomatal closure. 相似文献
59.
A new empirical-based scaling method is introduced to predict saturated hydraulic conductivity (K s ) of compacted soils. This method is an improvement of the former non-similar media concept (NSMC) model that is generalized for tilled and untilled conditions. In this method, geometric mean particle size diameter (dg ), geometric standard deviation (σ g ) and saturated soil water content (total porosity) are successfully incorporated in the empirical-based scaling factor of K s . Results showed that the scaled model overestimated K s by ~18%, whereas the NSMC model underestimated K s by ~21%. However, the scaled model based on the similar media concept (SMC) failed to predict K s . Because of the complexity and high uncertainty in determining the shape factor parameter in the NSMC model, it is suggested that the new scaled model might be used reliably in practical cases to predict K s in the various layers of compacted soils irrespective of the tillage condition. Further assessment of the new scaling model in other areas, in which new collected data are available, is recommended. 相似文献
60.
Mohammad Valipour Mirkhalegh Ziatabar Ahmadi Mahmoud Raeini-Sarjaz Mohammad Ali Gholami Sefidkouhi Ali Shahnazari Ramin Fazlola 《Archives of Agronomy and Soil Science》2013,59(5):657-678
The present paper aims to estimate the areas equipped for irrigation and desirability of agricultural water management in the world. For this purpose, all necessary information was gathered from Food and Agriculture Organization and checked using World Bank Group. The selected 18 indices were analysed for all 26 regions in the area studied, and the extent of area equipped for irrigation to cultivated area was estimated by 2 different formulas and other 9 indices. In addition, an average index was calculated using various methods to assess region conditions for agricultural water management. The results show that Central Asia is the best region for agricultural water management and the value of relative error is less than 20%. The capability of irrigation and drainage systems was studied using other eight indices with more limited information. The results indicated that trial-and-error policies should be avoided and expert comments be applied to irrigation systems for any crop. 相似文献