Effects of 15N-labelled ammonium nitrate and urea on soil nitrogen during growth of wheat (Triticum aestivum L.) under field conditions     

A. Hamid  M. Ahmad 《Biology and Fertility of Soils》1994,17(3):232-236

We studied the effects of ¹⁵N-labelled ammonium nitrate and urea on the yield and uptake of labelled and unlabelled N by wheat (Triticum aestivum L., cv. Mexi-Pak-65) in a field experiment. The dry matter and N yields were significantly increased with fertilizer N application compared to those from unfertilized soil. The wheat crop used 33.6–51.5 and 30.5–40.9% of the N from ammonium nitrate and urea, respectively. Splitting the fertilizer N application had a significant effect on the uptake of fertilizer N by the wheat. The fertilizer N uptake showed that ammonium nitrate was a more available source of N for wheat than urea. The effective use of fertilizer N (ratio of fertilizer N in grain to fertilizer N in whole plant) was statistically similar for the two N fertilizers. The application of fertilizer N increased the uptake of unlabelled soil N by wheat, a result attributed to a positive added N interaction, which varied according to the fertilizer N split; six split applications gave the highest added N interaction compared to a single application or two split applications for both fertilizers. Ammonium nitrate gave 90.5, 33.5, and 48.5% more added N interaction than urea with one, two, and six split N applications. A values were not significantly correlated with the added N interaction (r=0.557). The observed added N interaction may have been the result of pool substitution, whereby added labelled fertilizer N replaced unlabelled soil N.  相似文献   

Effects of irrigation strategies and soils on field grown potatoes: Root distribution   总被引：1，自引：0，他引：1  

Seyed Hamid Ahmadi  Finn PlauborgMathias N. Andersen  Ali Reza SepaskhahChristian R. Jensen  Søren Hansen 《Agricultural Water Management》2011,98(8):1280-1290

Root distribution of field grown potatoes (cv. Folva) was studied in 4.32 m² lysimeters and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. Drip irrigation was applied for all irrigations. Irrigations were run in three different soils: coarse sand, loamy sand, and sandy loam. Irrigation treatments started after tuber bulking and lasted until final harvest with PRD and DI receiving 65% of FI. Potatoes irrigated with water-saving irrigation techniques (PRD and DI) did not show statistically different dry root mass and root length density (RLD, cm root per cm³ soil) compared with root development in fully irrigated (FI) potatoes. Highest RLD existed in the top 30-40 cm of the ridge below which it decreased sharply. The RLD was distributed homogenously along the ridge and furrow but heterogeneously across the ridge and furrow with highest root density in the furrow. Most roots accumulated in the surface layers of coarse sand as compared to the other soil types. In the deep soil profile (30-70 cm) a higher root density was found in loamy sand compared with the sandy loam and coarse sand. Approximately twice the amounts of roots were found below the furrows compared with the corresponding layers below the ridges. The RLD values in the soil profile of the ridges and the furrows followed the Gerwitz and Page model: RLD = α × exp(−β × z). The highest value of surface root density (α) and rate of change in density (β) was found in coarse sand while the lowest values of α and β were found in the sandy loam and loamy sand. The model estimated the effective rooting depth in coarse sand and sandy loam quite well but did slightly overestimate it in the loamy sand. Statistical analysis showed that one α and β value can be used for each soil irrespective of the irrigation treatment. Thus, the effective rooting depths corresponding to root length densities of 0.1 and 0.25 cm cm⁻³ for sandy loam, loamy sand, and coarse sand soils were 99, 141, and 94 cm, and 80, 115, and 78 cm, respectively, calculated from top of the ridge. The findings of this study can be used in practice for efficient use of water and nutrients in the field.  相似文献   

An illustrated review on manifestation of pome fruit germplasm in the historic miniatures of ancient Persia     

Abdollahi  Hamid 《Genetic Resources and Crop Evolution》2021,68(7):2775-2791

Genetic Resources and Crop Evolution - Throughout history, territories under the rule of ancient Persian empires, including the plateau of Iran, parts of Central Asia and Transcaucasia, have been...  相似文献   

Association Study of rs1333040 and rs1004638 Polymorphisms in the 9p21 Locus with Coronary Artery Disease in Southwest of Iran     

Khadijeh Golabgir Khademi  Ali Mohammad Foroughmand  Hamid Galehdari  Saied Yazdankhah  Mahdi Pourmahdi Borujeni  Zahra Shahbazi  Parvaneh Dinarvand 《Iranian Biomedical Journal》2016,20(2):122-127

Background:

Coronary artery disease (CAD) is a multifactorial and heterogenic disease. Recently, genome-wide association studies have reported that rs1333040 (C/T) and rs1004638 (A/T) single nucleotide polymorphisms (SNPs) in the 9p21 locus have very strong association with CAD. This study aimed to examine these associations in Southwest of Iran.

Methods:

Blood samples were collected from 200 CAD patients and 110 healthy individuals with no CAD. The association of two SNPs with CAD was evaluated by PCR and restriction fragment length polymorphism.

Results:

Chi-square test showed no association between rs1333040 SNP and CAD (X²: 4.66, df: 2, P=0.09). Also, there was no association between rs1004638 SNP and CAD (X²: 0.27, df: 2, P=0.88).

Conclusion:

No association was observed between rs1333040 and rs1004638 SNPs in the 9P21 region and CAD in Southwest of Iran. Key Words: Coronary artery disease, Single nucleotide polymorphisms, Genetic association study, Iran  相似文献   

干旱区城市化对城市内河水质的影响研究——以吐曼河为例     

艾尼瓦尔·买买提  麦麦提吐尔逊·艾则孜  海米提·依米提 《水土保持研究》2007,14(3):188-191

随着城市社会经济的迅速发展，工业主导的城市化过程带来了许多城市生态环境问题，引起了城市内河水质的恶化。采用1996～2000年喀什市吐曼河水质观测数据、1990年与1999年卫星遥感图像和城市发展中有关的社会经济统计数据与土地利用资料，在3S技术的支持下，运用地表水污染综合指数法，对吐曼河水质进行评价，定量与定性相结合分析了干旱区城市化对城市内河水质的影响。结果表明：大气中的总悬浮颗粒是导致吐曼河水质严重污染的主要原因。此外，城市化所带来得人口增加、工业化与土地利用方式的改变也一定程度的影响了吐曼河的水质。  相似文献   

Heat inactivation of leafroll virus in potato tuber tissues     

A. Hamid  S. B. Locke 《American Journal of Potato Research》1961,38(9):304-310

Heat inactivation of leafroll virus in tuber tissues of three potato varieties (Russet Burbank, Katahdin, and Mohawk) was studied. Russet Burbank did not tolerate high constant temperatures and a low proportion of tubers and eye-pieces survived the treatments. On the other hand, Russet Burbank eye-pieces survived, with few exceptions, treatment at 40 C for four hours alternating with room temperaure (16–20 C) for 20 hours daily for as long as eight weeks. Inactivation of the virus was complete after six weeks of this treatment. Results obtained with the Katahdin and Mohawk varieties in similar tests were variable, and this possibly may be attributed to the higher room temperature (25–30 C) prevailing during these experiments.  相似文献   

Ultra-fast separation of wheat glutenin subunits by reversed-phase HPLC using a superficially porous silica-based column     

Hamid A. Naeem  Harry D. Sapirstein 《Journal of Cereal Science》2007

A relatively new, unique column packing material for reversed-phase high-performance liquid chromatography (RP-HPLC) was evaluated for rapid separation of wheat glutenin protein subunits. The product named “Poroshell” by the manufacturer consists of a solid core and a porous coat instead of solid silica spheres used in conventional RP-HPLC column packing. This architecture favours rapid mass transfer, facilitating faster reversed-phase separations of biomolecules compared to conventional silica columns. The main objective of this study was to evaluate the quality of separations of glutenin subunits (GS), as well as to optimize conditions to produce the fastest possible run times without sacrificing resolution using a Poroshell 300SB-C₈ 2.1×75 mm column. The stability of GS separations over time was also assessed. Two different bread wheat genotypes were used for optimization of separation conditions and six more common and durum wheat genotypes possessing different subunit combinations were used for further evaluation. Glutenin protein was extracted with 0.08 M Tris–HCl buffer (pH 7.5) containing 50% 1-propanol under reducing conditions after pre-extraction of soluble proteins with 50% 1-propanol. Optimization of GS resolution and sample throughput by RP-HPLC was assessed in response to variation in eluent flow rate, acetonitrile (ACN) gradient, and column temperature. The best resolution of both HMW- and LMW-GS was obtained in 13 min using a 23–44% ACN gradient with a flow rate of 0.7 mL/min at 65 °C. Subunit elution times and integrated areas were highly repeatable even after several hundred injections. Highly satisfactory separation of HMW-GS and quantification of ratio of HMW- to LMW-GS were achieved in less than 4 min per sample using a modified HPLC gradient. Ratio of HMW- to LMW-GS was unaffected by the speed of the separations. As well, the elution order of HMW- and LMW-GS was unaffected by the rapid analysis, compared to conventional RP-HPLC separations, so no new learning was required for interpreting chromatograms and classification of subunits. The rapid RP-HPLC method using the Poroshell column appears to be very well suited for routine quantification of HMW-GS and LMW-GS especially for purposes of wheat quality screening and wheat cultivar development activities where large numbers of samples are typically encountered.  相似文献   

Common carotid artery intima-media thickness and atherosclerotic plaques in carotid bulb in patients with chronic kidney disease on hemodialysis: a case-control study     

Shakeri A  Abdi M  Khosroshahi HT  Fouladi RF 《Pakistan journal of biological sciences: PJBS》2011,14(17):844-848

The Common Carotid artery Intima-Media Thickness (CCIMT) can reflect systemic atherosclerosis in renal patients on hemodialysis. This study aimed to compare CCIMT measured by color Doppler ultrasonography between two groups including dialytic patients and normal subjects. In this case-control setting, 48 patients with Chronic Kidney Disease (CKD) on hemodialysis (case group) and 46 age and sex-matched healthy subjects (control group) were enrolled in this study. Color Doppler ultrasound was used to measure CCIMT and determine presence of atherosclerotic plaques in carotid bulb in both groups. Various laboratory parameters were also determined. Serum levels of triglyceride, total cholesterol, low-density lipoprotein, fasting sugar, ionized calcium, inorganic phosphorus and magnesium were comparable between the two groups. Hypertension and elevated levels of serum C-reactive protein, as well as the mean levels of serum non-fasting homocysteine and phosphate were significantly higher in the case group. Mean levels of serum high-density lipoprotein and albumin were significantly higher in the controls. Mean maximum CCIMT was significantly higher in the case group than in controls (0.73 +/- 0.15 vs. 0.68 +/- 0.08 mm, p = 0.01) even after adjusting for other confounding variables. Frequency of patients with atherosclerotic plaques in carotid bulbs was not significantly different between case and controls. In conclusion, this study showed that CCIMT is significantly higher in CKD patients on hemodialysis comparing with matched normal counterparts. Furthermore, this difference was independent of other conventional risk factors for atherosclerosis.  相似文献   

INTERACTION BETWEEN WATER ALKALINITY AND NUTRIENT SOLUTION PH ON THE VEGETATIVE GROWTH,CHLOROPHYLL FLUORESCENCE AND LEAF MAGNESIUM,IRON, MANGANESE,AND ZINC CONCENTRATIONS IN LETTUCE     

Hamid R. Roosta 《Journal of plant nutrition》2013,36(5):717-731

Alkalinity of water is considered critical for plant growth. Interactions between water alkalinity and solution pH on lettuce were investigated. Seeds of romaine type lettuce were sown in pots containing perlite and irrigated with a high alkaline nutrient solution at four pH values (5, 6, 7, and 8). Considering the high amount of Fv/Fm at pH 5; higher shoot growth (at pH 5) could be due to the improvement of the efficiency of the photosynthesis apparatus of plants and consequently higher photochemical quantum yield. Although, magnesium (Mg) concentration in leaves increased with elevating pH up to 7 and then decreased at 8, but iron (Fe), manganese (Mn), and zinc (Zn) concentrations decreased at higher solution pH levels, constantly. In commercial lettuce production in which water with high pH and carbonate species is normally used, it is better to use safe acids to reduce the pH in nutrient solutions to 5.  相似文献   

Long-term land-use change effects on phosphorus fractionation in Zrêbar Lake margin soils     

Mohsen Sheklabadi  Hamid Mahmoudzadeh  Ali Akbar Mahboubi  Bahram Gharabaghi  Beau Ahrens 《Archives of Agronomy and Soil Science》2013,59(6):737-749

The aim of this study was to survey long-term changes in phosphorus (P) fractions in soils in different land uses. Sequential extraction had been used to determine soil P fractionation on the basis of land-use change, i.e. native forest to vineyard and wetland to both alfalfa and wheat at the end of 30 and 20 years, respectively. The highest values of labile-P (L-P) fractions in surface soil layers were observed in the cultivated land. The calcium-bound P was the most affected fraction by land-use change with the lowest amount in the vineyard and the highest amount in the alfalfa land. Conversion of forest to vineyards causes P in the soils to be more vulnerable to transmission; thus, the least amount of total P (T-P) in vineyard may be attributed to the removal of sediment and sediment bond P from runoff in response to land-use changes. Average L-P in alfalfa land was two times more than that in vineyard. Results showed that 44.5% of T-P in native land was stored in surface layer; besides, the portion of the arable surface horizon in T-P sequestration was 33%.  相似文献